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- arch
- ia64
- kernel
- perfmon.c
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/*
* This file implements the perfmon-2 subsystem which is used
* to program the IA-64 Performance Monitoring Unit (PMU).
*
* The initial version of perfmon.c was written by
* Ganesh Venkitachalam, IBM Corp.
*
* Then it was modified for perfmon-1.x by Stephane Eranian and
* David Mosberger, Hewlett Packard Co.
*
* Version Perfmon-2.x is a rewrite of perfmon-1.x
* by Stephane Eranian, Hewlett Packard Co.
*
* Copyright (C) 1999-2005 Hewlett Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* More information about perfmon available at:
* http://www.hpl.hp.com/research/linux/perfmon
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/sysctl.h>
#include <linux/list.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/vfs.h>
#include <linux/smp.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/rcupdate.h>
#include <linux/completion.h>
#include <linux/tracehook.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <asm/errno.h>
#include <asm/intrinsics.h>
#include <asm/page.h>
#include <asm/perfmon.h>
#include <asm/processor.h>
#include <asm/signal.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#ifdef CONFIG_PERFMON
/*
* perfmon context state
*/
#define PFM_CTX_UNLOADED 1 /* context is not loaded onto any task */
#define PFM_CTX_LOADED 2 /* context is loaded onto a task */
#define PFM_CTX_MASKED 3 /* context is loaded but monitoring is masked due to overflow */
#define PFM_CTX_ZOMBIE 4 /* owner of the context is closing it */
#define PFM_INVALID_ACTIVATION (~0UL)
#define PFM_NUM_PMC_REGS 64 /* PMC save area for ctxsw */
#define PFM_NUM_PMD_REGS 64 /* PMD save area for ctxsw */
/*
* depth of message queue
*/
#define PFM_MAX_MSGS 32
#define PFM_CTXQ_EMPTY(g) ((g)->ctx_msgq_head == (g)->ctx_msgq_tail)
/*
* type of a PMU register (bitmask).
* bitmask structure:
* bit0 : register implemented
* bit1 : end marker
* bit2-3 : reserved
* bit4 : pmc has pmc.pm
* bit5 : pmc controls a counter (has pmc.oi), pmd is used as counter
* bit6-7 : register type
* bit8-31: reserved
*/
#define PFM_REG_NOTIMPL 0x0 /* not implemented at all */
#define PFM_REG_IMPL 0x1 /* register implemented */
#define PFM_REG_END 0x2 /* end marker */
#define PFM_REG_MONITOR (0x1<<4|PFM_REG_IMPL) /* a PMC with a pmc.pm field only */
#define PFM_REG_COUNTING (0x2<<4|PFM_REG_MONITOR) /* a monitor + pmc.oi+ PMD used as a counter */
#define PFM_REG_CONTROL (0x4<<4|PFM_REG_IMPL) /* PMU control register */
#define PFM_REG_CONFIG (0x8<<4|PFM_REG_IMPL) /* configuration register */
#define PFM_REG_BUFFER (0xc<<4|PFM_REG_IMPL) /* PMD used as buffer */
#define PMC_IS_LAST(i) (pmu_conf->pmc_desc[i].type & PFM_REG_END)
#define PMD_IS_LAST(i) (pmu_conf->pmd_desc[i].type & PFM_REG_END)
#define PMC_OVFL_NOTIFY(ctx, i) ((ctx)->ctx_pmds[i].flags & PFM_REGFL_OVFL_NOTIFY)
/* i assumed unsigned */
#define PMC_IS_IMPL(i) (i< PMU_MAX_PMCS && (pmu_conf->pmc_desc[i].type & PFM_REG_IMPL))
#define PMD_IS_IMPL(i) (i< PMU_MAX_PMDS && (pmu_conf->pmd_desc[i].type & PFM_REG_IMPL))
/* XXX: these assume that register i is implemented */
#define PMD_IS_COUNTING(i) ((pmu_conf->pmd_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
#define PMC_IS_COUNTING(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
#define PMC_IS_MONITOR(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_MONITOR) == PFM_REG_MONITOR)
#define PMC_IS_CONTROL(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_CONTROL) == PFM_REG_CONTROL)
#define PMC_DFL_VAL(i) pmu_conf->pmc_desc[i].default_value
#define PMC_RSVD_MASK(i) pmu_conf->pmc_desc[i].reserved_mask
#define PMD_PMD_DEP(i) pmu_conf->pmd_desc[i].dep_pmd[0]
#define PMC_PMD_DEP(i) pmu_conf->pmc_desc[i].dep_pmd[0]
#define PFM_NUM_IBRS IA64_NUM_DBG_REGS
#define PFM_NUM_DBRS IA64_NUM_DBG_REGS
#define CTX_OVFL_NOBLOCK(c) ((c)->ctx_fl_block == 0)
#define CTX_HAS_SMPL(c) ((c)->ctx_fl_is_sampling)
#define PFM_CTX_TASK(h) (h)->ctx_task
#define PMU_PMC_OI 5 /* position of pmc.oi bit */
/* XXX: does not support more than 64 PMDs */
#define CTX_USED_PMD(ctx, mask) (ctx)->ctx_used_pmds[0] |= (mask)
#define CTX_IS_USED_PMD(ctx, c) (((ctx)->ctx_used_pmds[0] & (1UL << (c))) != 0UL)
#define CTX_USED_MONITOR(ctx, mask) (ctx)->ctx_used_monitors[0] |= (mask)
#define CTX_USED_IBR(ctx,n) (ctx)->ctx_used_ibrs[(n)>>6] |= 1UL<< ((n) % 64)
#define CTX_USED_DBR(ctx,n) (ctx)->ctx_used_dbrs[(n)>>6] |= 1UL<< ((n) % 64)
#define CTX_USES_DBREGS(ctx) (((pfm_context_t *)(ctx))->ctx_fl_using_dbreg==1)
#define PFM_CODE_RR 0 /* requesting code range restriction */
#define PFM_DATA_RR 1 /* requestion data range restriction */
#define PFM_CPUINFO_CLEAR(v) pfm_get_cpu_var(pfm_syst_info) &= ~(v)
#define PFM_CPUINFO_SET(v) pfm_get_cpu_var(pfm_syst_info) |= (v)
#define PFM_CPUINFO_GET() pfm_get_cpu_var(pfm_syst_info)
#define RDEP(x) (1UL<<(x))
/*
* context protection macros
* in SMP:
* - we need to protect against CPU concurrency (spin_lock)
* - we need to protect against PMU overflow interrupts (local_irq_disable)
* in UP:
* - we need to protect against PMU overflow interrupts (local_irq_disable)
*
* spin_lock_irqsave()/spin_unlock_irqrestore():
* in SMP: local_irq_disable + spin_lock
* in UP : local_irq_disable
*
* spin_lock()/spin_lock():
* in UP : removed automatically
* in SMP: protect against context accesses from other CPU. interrupts
* are not masked. This is useful for the PMU interrupt handler
* because we know we will not get PMU concurrency in that code.
*/
#define PROTECT_CTX(c, f) \
do { \
DPRINT(("spinlock_irq_save ctx %p by [%d]\n", c, task_pid_nr(current))); \
spin_lock_irqsave(&(c)->ctx_lock, f); \
DPRINT(("spinlocked ctx %p by [%d]\n", c, task_pid_nr(current))); \
} while(0)
#define UNPROTECT_CTX(c, f) \
do { \
DPRINT(("spinlock_irq_restore ctx %p by [%d]\n", c, task_pid_nr(current))); \
spin_unlock_irqrestore(&(c)->ctx_lock, f); \
} while(0)
#define PROTECT_CTX_NOPRINT(c, f) \
do { \
spin_lock_irqsave(&(c)->ctx_lock, f); \
} while(0)
#define UNPROTECT_CTX_NOPRINT(c, f) \
do { \
spin_unlock_irqrestore(&(c)->ctx_lock, f); \
} while(0)
#define PROTECT_CTX_NOIRQ(c) \
do { \
spin_lock(&(c)->ctx_lock); \
} while(0)
#define UNPROTECT_CTX_NOIRQ(c) \
do { \
spin_unlock(&(c)->ctx_lock); \
} while(0)
#ifdef CONFIG_SMP
#define GET_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)
#define INC_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)++
#define SET_ACTIVATION(c) (c)->ctx_last_activation = GET_ACTIVATION()
#else /* !CONFIG_SMP */
#define SET_ACTIVATION(t) do {} while(0)
#define GET_ACTIVATION(t) do {} while(0)
#define INC_ACTIVATION(t) do {} while(0)
#endif /* CONFIG_SMP */
#define SET_PMU_OWNER(t, c) do { pfm_get_cpu_var(pmu_owner) = (t); pfm_get_cpu_var(pmu_ctx) = (c); } while(0)
#define GET_PMU_OWNER() pfm_get_cpu_var(pmu_owner)
#define GET_PMU_CTX() pfm_get_cpu_var(pmu_ctx)
#define LOCK_PFS(g) spin_lock_irqsave(&pfm_sessions.pfs_lock, g)
#define UNLOCK_PFS(g) spin_unlock_irqrestore(&pfm_sessions.pfs_lock, g)
#define PFM_REG_RETFLAG_SET(flags, val) do { flags &= ~PFM_REG_RETFL_MASK; flags |= (val); } while(0)
/*
* cmp0 must be the value of pmc0
*/
#define PMC0_HAS_OVFL(cmp0) (cmp0 & ~0x1UL)
#define PFMFS_MAGIC 0xa0b4d889
/*
* debugging
*/
#define PFM_DEBUGGING 1
#ifdef PFM_DEBUGGING
#define DPRINT(a) \
do { \
if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
} while (0)
#define DPRINT_ovfl(a) \
do { \
if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
} while (0)
#endif
/*
* 64-bit software counter structure
*
* the next_reset_type is applied to the next call to pfm_reset_regs()
*/
typedef struct {
unsigned long val; /* virtual 64bit counter value */
unsigned long lval; /* last reset value */
unsigned long long_reset; /* reset value on sampling overflow */
unsigned long short_reset; /* reset value on overflow */
unsigned long reset_pmds[4]; /* which other pmds to reset when this counter overflows */
unsigned long smpl_pmds[4]; /* which pmds are accessed when counter overflow */
unsigned long seed; /* seed for random-number generator */
unsigned long mask; /* mask for random-number generator */
unsigned int flags; /* notify/do not notify */
unsigned long eventid; /* overflow event identifier */
} pfm_counter_t;
/*
* context flags
*/
typedef struct {
unsigned int block:1; /* when 1, task will blocked on user notifications */
unsigned int system:1; /* do system wide monitoring */
unsigned int using_dbreg:1; /* using range restrictions (debug registers) */
unsigned int is_sampling:1; /* true if using a custom format */
unsigned int excl_idle:1; /* exclude idle task in system wide session */
unsigned int going_zombie:1; /* context is zombie (MASKED+blocking) */
unsigned int trap_reason:2; /* reason for going into pfm_handle_work() */
unsigned int no_msg:1; /* no message sent on overflow */
unsigned int can_restart:1; /* allowed to issue a PFM_RESTART */
unsigned int reserved:22;
} pfm_context_flags_t;
#define PFM_TRAP_REASON_NONE 0x0 /* default value */
#define PFM_TRAP_REASON_BLOCK 0x1 /* we need to block on overflow */
#define PFM_TRAP_REASON_RESET 0x2 /* we need to reset PMDs */
/*
* perfmon context: encapsulates all the state of a monitoring session
*/
typedef struct pfm_context {
spinlock_t ctx_lock; /* context protection */
pfm_context_flags_t ctx_flags; /* bitmask of flags (block reason incl.) */
unsigned int ctx_state; /* state: active/inactive (no bitfield) */
struct task_struct *ctx_task; /* task to which context is attached */
unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
struct completion ctx_restart_done; /* use for blocking notification mode */
unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
unsigned long ctx_reload_pmds[4]; /* bitmask of force reload PMD on ctxsw in */
unsigned long ctx_all_pmcs[4]; /* bitmask of all accessible PMCs */
unsigned long ctx_reload_pmcs[4]; /* bitmask of force reload PMC on ctxsw in */
unsigned long ctx_used_monitors[4]; /* bitmask of monitor PMC being used */
unsigned long ctx_pmcs[PFM_NUM_PMC_REGS]; /* saved copies of PMC values */
unsigned int ctx_used_ibrs[1]; /* bitmask of used IBR (speedup ctxsw in) */
unsigned int ctx_used_dbrs[1]; /* bitmask of used DBR (speedup ctxsw in) */
unsigned long ctx_dbrs[IA64_NUM_DBG_REGS]; /* DBR values (cache) when not loaded */
unsigned long ctx_ibrs[IA64_NUM_DBG_REGS]; /* IBR values (cache) when not loaded */
pfm_counter_t ctx_pmds[PFM_NUM_PMD_REGS]; /* software state for PMDS */
unsigned long th_pmcs[PFM_NUM_PMC_REGS]; /* PMC thread save state */
unsigned long th_pmds[PFM_NUM_PMD_REGS]; /* PMD thread save state */
unsigned long ctx_saved_psr_up; /* only contains psr.up value */
unsigned long ctx_last_activation; /* context last activation number for last_cpu */
unsigned int ctx_last_cpu; /* CPU id of current or last CPU used (SMP only) */
unsigned int ctx_cpu; /* cpu to which perfmon is applied (system wide) */
int ctx_fd; /* file descriptor used my this context */
pfm_ovfl_arg_t ctx_ovfl_arg; /* argument to custom buffer format handler */
pfm_buffer_fmt_t *ctx_buf_fmt; /* buffer format callbacks */
void *ctx_smpl_hdr; /* points to sampling buffer header kernel vaddr */
unsigned long ctx_smpl_size; /* size of sampling buffer */
void *ctx_smpl_vaddr; /* user level virtual address of smpl buffer */
wait_queue_head_t ctx_msgq_wait;
pfm_msg_t ctx_msgq[PFM_MAX_MSGS];
int ctx_msgq_head;
int ctx_msgq_tail;
struct fasync_struct *ctx_async_queue;
wait_queue_head_t ctx_zombieq; /* termination cleanup wait queue */
} pfm_context_t;
/*
* magic number used to verify that structure is really
* a perfmon context
*/
#define PFM_IS_FILE(f) ((f)->f_op == &pfm_file_ops)
#define PFM_GET_CTX(t) ((pfm_context_t *)(t)->thread.pfm_context)
#ifdef CONFIG_SMP
#define SET_LAST_CPU(ctx, v) (ctx)->ctx_last_cpu = (v)
#define GET_LAST_CPU(ctx) (ctx)->ctx_last_cpu
#else
#define SET_LAST_CPU(ctx, v) do {} while(0)
#define GET_LAST_CPU(ctx) do {} while(0)
#endif
#define ctx_fl_block ctx_flags.block
#define ctx_fl_system ctx_flags.system
#define ctx_fl_using_dbreg ctx_flags.using_dbreg
#define ctx_fl_is_sampling ctx_flags.is_sampling
#define ctx_fl_excl_idle ctx_flags.excl_idle
#define ctx_fl_going_zombie ctx_flags.going_zombie
#define ctx_fl_trap_reason ctx_flags.trap_reason
#define ctx_fl_no_msg ctx_flags.no_msg
#define ctx_fl_can_restart ctx_flags.can_restart
#define PFM_SET_WORK_PENDING(t, v) do { (t)->thread.pfm_needs_checking = v; } while(0);
#define PFM_GET_WORK_PENDING(t) (t)->thread.pfm_needs_checking
/*
* global information about all sessions
* mostly used to synchronize between system wide and per-process
*/
typedef struct {
spinlock_t pfs_lock; /* lock the structure */
unsigned int pfs_task_sessions; /* number of per task sessions */
unsigned int pfs_sys_sessions; /* number of per system wide sessions */
unsigned int pfs_sys_use_dbregs; /* incremented when a system wide session uses debug regs */
unsigned int pfs_ptrace_use_dbregs; /* incremented when a process uses debug regs */
struct task_struct *pfs_sys_session[NR_CPUS]; /* point to task owning a system-wide session */
} pfm_session_t;
/*
* information about a PMC or PMD.
* dep_pmd[]: a bitmask of dependent PMD registers
* dep_pmc[]: a bitmask of dependent PMC registers
*/
typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
typedef struct {
unsigned int type;
int pm_pos;
unsigned long default_value; /* power-on default value */
unsigned long reserved_mask; /* bitmask of reserved bits */
pfm_reg_check_t read_check;
pfm_reg_check_t write_check;
unsigned long dep_pmd[4];
unsigned long dep_pmc[4];
} pfm_reg_desc_t;
/* assume cnum is a valid monitor */
#define PMC_PM(cnum, val) (((val) >> (pmu_conf->pmc_desc[cnum].pm_pos)) & 0x1)
/*
* This structure is initialized at boot time and contains
* a description of the PMU main characteristics.
*
* If the probe function is defined, detection is based
* on its return value:
* - 0 means recognized PMU
* - anything else means not supported
* When the probe function is not defined, then the pmu_family field
* is used and it must match the host CPU family such that:
* - cpu->family & config->pmu_family != 0
*/
typedef struct {
unsigned long ovfl_val; /* overflow value for counters */
pfm_reg_desc_t *pmc_desc; /* detailed PMC register dependencies descriptions */
pfm_reg_desc_t *pmd_desc; /* detailed PMD register dependencies descriptions */
unsigned int num_pmcs; /* number of PMCS: computed at init time */
unsigned int num_pmds; /* number of PMDS: computed at init time */
unsigned long impl_pmcs[4]; /* bitmask of implemented PMCS */
unsigned long impl_pmds[4]; /* bitmask of implemented PMDS */
char *pmu_name; /* PMU family name */
unsigned int pmu_family; /* cpuid family pattern used to identify pmu */
unsigned int flags; /* pmu specific flags */
unsigned int num_ibrs; /* number of IBRS: computed at init time */
unsigned int num_dbrs; /* number of DBRS: computed at init time */
unsigned int num_counters; /* PMC/PMD counting pairs : computed at init time */
int (*probe)(void); /* customized probe routine */
unsigned int use_rr_dbregs:1; /* set if debug registers used for range restriction */
} pmu_config_t;
/*
* PMU specific flags
*/
#define PFM_PMU_IRQ_RESEND 1 /* PMU needs explicit IRQ resend */
/*
* debug register related type definitions
*/
typedef struct {
unsigned long ibr_mask:56;
unsigned long ibr_plm:4;
unsigned long ibr_ig:3;
unsigned long ibr_x:1;
} ibr_mask_reg_t;
typedef struct {
unsigned long dbr_mask:56;
unsigned long dbr_plm:4;
unsigned long dbr_ig:2;
unsigned long dbr_w:1;
unsigned long dbr_r:1;
} dbr_mask_reg_t;
typedef union {
unsigned long val;
ibr_mask_reg_t ibr;
dbr_mask_reg_t dbr;
} dbreg_t;
/*
* perfmon command descriptions
*/
typedef struct {
int (*cmd_func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
char *cmd_name;
int cmd_flags;
unsigned int cmd_narg;
size_t cmd_argsize;
int (*cmd_getsize)(void *arg, size_t *sz);
} pfm_cmd_desc_t;
#define PFM_CMD_FD 0x01 /* command requires a file descriptor */
#define PFM_CMD_ARG_READ 0x02 /* command must read argument(s) */
#define PFM_CMD_ARG_RW 0x04 /* command must read/write argument(s) */
#define PFM_CMD_STOP 0x08 /* command does not work on zombie context */
#define PFM_CMD_NAME(cmd) pfm_cmd_tab[(cmd)].cmd_name
#define PFM_CMD_READ_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_READ)
#define PFM_CMD_RW_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_RW)
#define PFM_CMD_USE_FD(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_FD)
#define PFM_CMD_STOPPED(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_STOP)
#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
typedef struct {
unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
unsigned long pfm_ovfl_intr_count; /* keep track of ovfl interrupts */
unsigned long pfm_ovfl_intr_cycles; /* cycles spent processing ovfl interrupts */
unsigned long pfm_ovfl_intr_cycles_min; /* min cycles spent processing ovfl interrupts */
unsigned long pfm_ovfl_intr_cycles_max; /* max cycles spent processing ovfl interrupts */
unsigned long pfm_smpl_handler_calls;
unsigned long pfm_smpl_handler_cycles;
char pad[SMP_CACHE_BYTES] ____cacheline_aligned;
} pfm_stats_t;
/*
* perfmon internal variables
*/
static pfm_stats_t pfm_stats[NR_CPUS];
static pfm_session_t pfm_sessions; /* global sessions information */
static DEFINE_SPINLOCK(pfm_alt_install_check);
static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
static struct proc_dir_entry *perfmon_dir;
static pfm_uuid_t pfm_null_uuid = {0,};
static spinlock_t pfm_buffer_fmt_lock;
static LIST_HEAD(pfm_buffer_fmt_list);
static pmu_config_t *pmu_conf;
/* sysctl() controls */
pfm_sysctl_t pfm_sysctl;
EXPORT_SYMBOL(pfm_sysctl);
static ctl_table pfm_ctl_table[]={
{
.procname = "debug",
.data = &pfm_sysctl.debug,
.maxlen = sizeof(int),
.mode = 0666,
.proc_handler = proc_dointvec,
},
{
.procname = "debug_ovfl",
.data = &pfm_sysctl.debug_ovfl,
.maxlen = sizeof(int),
.mode = 0666,
.proc_handler = proc_dointvec,
},
{
.procname = "fastctxsw",
.data = &pfm_sysctl.fastctxsw,
.maxlen = sizeof(int),
.mode = 0600,
.proc_handler = proc_dointvec,
},
{
.procname = "expert_mode",
.data = &pfm_sysctl.expert_mode,
.maxlen = sizeof(int),
.mode = 0600,
.proc_handler = proc_dointvec,
},
{}
};
static ctl_table pfm_sysctl_dir[] = {
{
.procname = "perfmon",
.mode = 0555,
.child = pfm_ctl_table,
},
{}
};
static ctl_table pfm_sysctl_root[] = {
{
.procname = "kernel",
.mode = 0555,
.child = pfm_sysctl_dir,
},
{}
};
static struct ctl_table_header *pfm_sysctl_header;
static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
#define pfm_get_cpu_var(v) __ia64_per_cpu_var(v)
#define pfm_get_cpu_data(a,b) per_cpu(a, b)
static inline void
pfm_put_task(struct task_struct *task)
{
if (task != current) put_task_struct(task);
}
static inline void
pfm_reserve_page(unsigned long a)
{
SetPageReserved(vmalloc_to_page((void *)a));
}
static inline void
pfm_unreserve_page(unsigned long a)
{
ClearPageReserved(vmalloc_to_page((void*)a));
}
static inline unsigned long
pfm_protect_ctx_ctxsw(pfm_context_t *x)
{
spin_lock(&(x)->ctx_lock);
return 0UL;
}
static inline void
pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
{
spin_unlock(&(x)->ctx_lock);
}
/* forward declaration */
static const struct dentry_operations pfmfs_dentry_operations;
static struct dentry *
pfmfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data)
{
return mount_pseudo(fs_type, "pfm:", NULL, &pfmfs_dentry_operations,
PFMFS_MAGIC);
}
static struct file_system_type pfm_fs_type = {
.name = "pfmfs",
.mount = pfmfs_mount,
.kill_sb = kill_anon_super,
};
MODULE_ALIAS_FS("pfmfs");
DEFINE_PER_CPU(unsigned long, pfm_syst_info);
DEFINE_PER_CPU(struct task_struct *, pmu_owner);
DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
DEFINE_PER_CPU(unsigned long, pmu_activation_number);
EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
/* forward declaration */
static const struct file_operations pfm_file_ops;
/*
* forward declarations
*/
#ifndef CONFIG_SMP
static void pfm_lazy_save_regs (struct task_struct *ta);
#endif
void dump_pmu_state(const char *);
static int pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
#include "perfmon_itanium.h"
#include "perfmon_mckinley.h"
#include "perfmon_montecito.h"
#include "perfmon_generic.h"
static pmu_config_t *pmu_confs[]={
&pmu_conf_mont,
&pmu_conf_mck,
&pmu_conf_ita,
&pmu_conf_gen, /* must be last */
NULL
};
static int pfm_end_notify_user(pfm_context_t *ctx);
static inline void
pfm_clear_psr_pp(void)
{
ia64_rsm(IA64_PSR_PP);
ia64_srlz_i();
}
static inline void
pfm_set_psr_pp(void)
{
ia64_ssm(IA64_PSR_PP);
ia64_srlz_i();
}
static inline void
pfm_clear_psr_up(void)
{
ia64_rsm(IA64_PSR_UP);
ia64_srlz_i();
}
static inline void
pfm_set_psr_up(void)
{
ia64_ssm(IA64_PSR_UP);
ia64_srlz_i();
}
static inline unsigned long
pfm_get_psr(void)
{
unsigned long tmp;
tmp = ia64_getreg(_IA64_REG_PSR);
ia64_srlz_i();
return tmp;
}
static inline void
pfm_set_psr_l(unsigned long val)
{
ia64_setreg(_IA64_REG_PSR_L, val);
ia64_srlz_i();
}
static inline void
pfm_freeze_pmu(void)
{
ia64_set_pmc(0,1UL);
ia64_srlz_d();
}
static inline void
pfm_unfreeze_pmu(void)
{
ia64_set_pmc(0,0UL);
ia64_srlz_d();
}
static inline void
pfm_restore_ibrs(unsigned long *ibrs, unsigned int nibrs)
{
int i;
for (i=0; i < nibrs; i++) {
ia64_set_ibr(i, ibrs[i]);
ia64_dv_serialize_instruction();
}
ia64_srlz_i();
}
static inline void
pfm_restore_dbrs(unsigned long *dbrs, unsigned int ndbrs)
{
int i;
for (i=0; i < ndbrs; i++) {
ia64_set_dbr(i, dbrs[i]);
ia64_dv_serialize_data();
}
ia64_srlz_d();
}
/*
* PMD[i] must be a counter. no check is made
*/
static inline unsigned long
pfm_read_soft_counter(pfm_context_t *ctx, int i)
{
return ctx->ctx_pmds[i].val + (ia64_get_pmd(i) & pmu_conf->ovfl_val);
}
/*
* PMD[i] must be a counter. no check is made
*/
static inline void
pfm_write_soft_counter(pfm_context_t *ctx, int i, unsigned long val)
{
unsigned long ovfl_val = pmu_conf->ovfl_val;
ctx->ctx_pmds[i].val = val & ~ovfl_val;
/*
* writing to unimplemented part is ignore, so we do not need to
* mask off top part
*/
ia64_set_pmd(i, val & ovfl_val);
}
static pfm_msg_t *
pfm_get_new_msg(pfm_context_t *ctx)
{
int idx, next;
next = (ctx->ctx_msgq_tail+1) % PFM_MAX_MSGS;
DPRINT(("ctx_fd=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
if (next == ctx->ctx_msgq_head) return NULL;
idx = ctx->ctx_msgq_tail;
ctx->ctx_msgq_tail = next;
DPRINT(("ctx=%p head=%d tail=%d msg=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, idx));
return ctx->ctx_msgq+idx;
}
static pfm_msg_t *
pfm_get_next_msg(pfm_context_t *ctx)
{
pfm_msg_t *msg;
DPRINT(("ctx=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
if (PFM_CTXQ_EMPTY(ctx)) return NULL;
/*
* get oldest message
*/
msg = ctx->ctx_msgq+ctx->ctx_msgq_head;
/*
* and move forward
*/
ctx->ctx_msgq_head = (ctx->ctx_msgq_head+1) % PFM_MAX_MSGS;
DPRINT(("ctx=%p head=%d tail=%d type=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, msg->pfm_gen_msg.msg_type));
return msg;
}
static void
pfm_reset_msgq(pfm_context_t *ctx)
{
ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
DPRINT(("ctx=%p msgq reset\n", ctx));
}
static void *
pfm_rvmalloc(unsigned long size)
{
void *mem;
unsigned long addr;
size = PAGE_ALIGN(size);
mem = vzalloc(size);
if (mem) {
//printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);
addr = (unsigned long)mem;
while (size > 0) {
pfm_reserve_page(addr);
addr+=PAGE_SIZE;
size-=PAGE_SIZE;
}
}
return mem;
}
static void
pfm_rvfree(void *mem, unsigned long size)
{
unsigned long addr;
if (mem) {
DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));
addr = (unsigned long) mem;
while ((long) size > 0) {
pfm_unreserve_page(addr);
addr+=PAGE_SIZE;
size-=PAGE_SIZE;
}
vfree(mem);
}
return;
}
static pfm_context_t *
pfm_context_alloc(int ctx_flags)
{
pfm_context_t *ctx;
/*
* allocate context descriptor
* must be able to free with interrupts disabled
*/
ctx = kzalloc(sizeof(pfm_context_t), GFP_KERNEL);
if (ctx) {
DPRINT(("alloc ctx @%p\n", ctx));
/*
* init context protection lock
*/
spin_lock_init(&ctx->ctx_lock);
/*
* context is unloaded
*/
ctx->ctx_state = PFM_CTX_UNLOADED;
/*
* initialization of context's flags
*/
ctx->ctx_fl_block = (ctx_flags & PFM_FL_NOTIFY_BLOCK) ? 1 : 0;
ctx->ctx_fl_system = (ctx_flags & PFM_FL_SYSTEM_WIDE) ? 1: 0;
ctx->ctx_fl_no_msg = (ctx_flags & PFM_FL_OVFL_NO_MSG) ? 1: 0;
/*
* will move to set properties
* ctx->ctx_fl_excl_idle = (ctx_flags & PFM_FL_EXCL_IDLE) ? 1: 0;
*/
/*
* init restart semaphore to locked
*/
init_completion(&ctx->ctx_restart_done);
/*
* activation is used in SMP only
*/
ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
SET_LAST_CPU(ctx, -1);
/*
* initialize notification message queue
*/
ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
init_waitqueue_head(&ctx->ctx_msgq_wait);
init_waitqueue_head(&ctx->ctx_zombieq);
}
return ctx;
}
static void
pfm_context_free(pfm_context_t *ctx)
{
if (ctx) {
DPRINT(("free ctx @%p\n", ctx));
kfree(ctx);
}
}
static void
pfm_mask_monitoring(struct task_struct *task)
{
pfm_context_t *ctx = PFM_GET_CTX(task);
unsigned long mask, val, ovfl_mask;
int i;
DPRINT_ovfl(("masking monitoring for [%d]\n", task_pid_nr(task)));
ovfl_mask = pmu_conf->ovfl_val;
/*
* monitoring can only be masked as a result of a valid
* counter overflow. In UP, it means that the PMU still
* has an owner. Note that the owner can be different
* from the current task. However the PMU state belongs
* to the owner.
* In SMP, a valid overflow only happens when task is
* current. Therefore if we come here, we know that
* the PMU state belongs to the current task, therefore
* we can access the live registers.
*
* So in both cases, the live register contains the owner's
* state. We can ONLY touch the PMU registers and NOT the PSR.
*
* As a consequence to this call, the ctx->th_pmds[] array
* contains stale information which must be ignored
* when context is reloaded AND monitoring is active (see
* pfm_restart).
*/
mask = ctx->ctx_used_pmds[0];
for (i = 0; mask; i++, mask>>=1) {
/* skip non used pmds */
if ((mask & 0x1) == 0) continue;
val = ia64_get_pmd(i);
if (PMD_IS_COUNTING(i)) {
/*
* we rebuild the full 64 bit value of the counter
*/
ctx->ctx_pmds[i].val += (val & ovfl_mask);
} else {
ctx->ctx_pmds[i].val = val;
}
DPRINT_ovfl(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
i,
ctx->ctx_pmds[i].val,
val & ovfl_mask));
}
/*
* mask monitoring by setting the privilege level to 0
* we cannot use psr.pp/psr.up for this, it is controlled by
* the user
*
* if task is current, modify actual registers, otherwise modify
* thread save state, i.e., what will be restored in pfm_load_regs()
*/
mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0UL) continue;
ia64_set_pmc(i, ctx->th_pmcs[i] & ~0xfUL);
ctx->th_pmcs[i] &= ~0xfUL;
DPRINT_ovfl(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
}
/*
* make all of this visible
*/
ia64_srlz_d();
}
/*
* must always be done with task == current
*
* context must be in MASKED state when calling
*/
static void
pfm_restore_monitoring(struct task_struct *task)
{
pfm_context_t *ctx = PFM_GET_CTX(task);
unsigned long mask, ovfl_mask;
unsigned long psr, val;
int i, is_system;
is_system = ctx->ctx_fl_system;
ovfl_mask = pmu_conf->ovfl_val;
if (task != current) {
printk(KERN_ERR "perfmon.%d: invalid task[%d] current[%d]\n", __LINE__, task_pid_nr(task), task_pid_nr(current));
return;
}
if (ctx->ctx_state != PFM_CTX_MASKED) {
printk(KERN_ERR "perfmon.%d: task[%d] current[%d] invalid state=%d\n", __LINE__,
task_pid_nr(task), task_pid_nr(current), ctx->ctx_state);
return;
}
psr = pfm_get_psr();
/*
* monitoring is masked via the PMC.
* As we restore their value, we do not want each counter to
* restart right away. We stop monitoring using the PSR,
* restore the PMC (and PMD) and then re-establish the psr
* as it was. Note that there can be no pending overflow at
* this point, because monitoring was MASKED.
*
* system-wide session are pinned and self-monitoring
*/
if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
/* disable dcr pp */
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
pfm_clear_psr_pp();
} else {
pfm_clear_psr_up();
}
/*
* first, we restore the PMD
*/
mask = ctx->ctx_used_pmds[0];
for (i = 0; mask; i++, mask>>=1) {
/* skip non used pmds */
if ((mask & 0x1) == 0) continue;
if (PMD_IS_COUNTING(i)) {
/*
* we split the 64bit value according to
* counter width
*/
val = ctx->ctx_pmds[i].val & ovfl_mask;
ctx->ctx_pmds[i].val &= ~ovfl_mask;
} else {
val = ctx->ctx_pmds[i].val;
}
ia64_set_pmd(i, val);
DPRINT(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
i,
ctx->ctx_pmds[i].val,
val));
}
/*
* restore the PMCs
*/
mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0UL) continue;
ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
ia64_set_pmc(i, ctx->th_pmcs[i]);
DPRINT(("[%d] pmc[%d]=0x%lx\n",
task_pid_nr(task), i, ctx->th_pmcs[i]));
}
ia64_srlz_d();
/*
* must restore DBR/IBR because could be modified while masked
* XXX: need to optimize
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* now restore PSR
*/
if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
/* enable dcr pp */
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
ia64_srlz_i();
}
pfm_set_psr_l(psr);
}
static inline void
pfm_save_pmds(unsigned long *pmds, unsigned long mask)
{
int i;
ia64_srlz_d();
for (i=0; mask; i++, mask>>=1) {
if (mask & 0x1) pmds[i] = ia64_get_pmd(i);
}
}
/*
* reload from thread state (used for ctxw only)
*/
static inline void
pfm_restore_pmds(unsigned long *pmds, unsigned long mask)
{
int i;
unsigned long val, ovfl_val = pmu_conf->ovfl_val;
for (i=0; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0) continue;
val = PMD_IS_COUNTING(i) ? pmds[i] & ovfl_val : pmds[i];
ia64_set_pmd(i, val);
}
ia64_srlz_d();
}
/*
* propagate PMD from context to thread-state
*/
static inline void
pfm_copy_pmds(struct task_struct *task, pfm_context_t *ctx)
{
unsigned long ovfl_val = pmu_conf->ovfl_val;
unsigned long mask = ctx->ctx_all_pmds[0];
unsigned long val;
int i;
DPRINT(("mask=0x%lx\n", mask));
for (i=0; mask; i++, mask>>=1) {
val = ctx->ctx_pmds[i].val;
/*
* We break up the 64 bit value into 2 pieces
* the lower bits go to the machine state in the
* thread (will be reloaded on ctxsw in).
* The upper part stays in the soft-counter.
*/
if (PMD_IS_COUNTING(i)) {
ctx->ctx_pmds[i].val = val & ~ovfl_val;
val &= ovfl_val;
}
ctx->th_pmds[i] = val;
DPRINT(("pmd[%d]=0x%lx soft_val=0x%lx\n",
i,
ctx->th_pmds[i],
ctx->ctx_pmds[i].val));
}
}
/*
* propagate PMC from context to thread-state
*/
static inline void
pfm_copy_pmcs(struct task_struct *task, pfm_context_t *ctx)
{
unsigned long mask = ctx->ctx_all_pmcs[0];
int i;
DPRINT(("mask=0x%lx\n", mask));
for (i=0; mask; i++, mask>>=1) {
/* masking 0 with ovfl_val yields 0 */
ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
DPRINT(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
}
}
static inline void
pfm_restore_pmcs(unsigned long *pmcs, unsigned long mask)
{
int i;
for (i=0; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0) continue;
ia64_set_pmc(i, pmcs[i]);
}
ia64_srlz_d();
}
static inline int
pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
{
return memcmp(a, b, sizeof(pfm_uuid_t));
}
static inline int
pfm_buf_fmt_exit(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, struct pt_regs *regs)
{
int ret = 0;
if (fmt->fmt_exit) ret = (*fmt->fmt_exit)(task, buf, regs);
return ret;
}
static inline int
pfm_buf_fmt_getsize(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags, int cpu, void *arg, unsigned long *size)
{
int ret = 0;
if (fmt->fmt_getsize) ret = (*fmt->fmt_getsize)(task, flags, cpu, arg, size);
return ret;
}
static inline int
pfm_buf_fmt_validate(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags,
int cpu, void *arg)
{
int ret = 0;
if (fmt->fmt_validate) ret = (*fmt->fmt_validate)(task, flags, cpu, arg);
return ret;
}
static inline int
pfm_buf_fmt_init(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, unsigned int flags,
int cpu, void *arg)
{
int ret = 0;
if (fmt->fmt_init) ret = (*fmt->fmt_init)(task, buf, flags, cpu, arg);
return ret;
}
static inline int
pfm_buf_fmt_restart(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
{
int ret = 0;
if (fmt->fmt_restart) ret = (*fmt->fmt_restart)(task, ctrl, buf, regs);
return ret;
}
static inline int
pfm_buf_fmt_restart_active(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
{
int ret = 0;
if (fmt->fmt_restart_active) ret = (*fmt->fmt_restart_active)(task, ctrl, buf, regs);
return ret;
}
static pfm_buffer_fmt_t *
__pfm_find_buffer_fmt(pfm_uuid_t uuid)
{
struct list_head * pos;
pfm_buffer_fmt_t * entry;
list_for_each(pos, &pfm_buffer_fmt_list) {
entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
if (pfm_uuid_cmp(uuid, entry->fmt_uuid) == 0)
return entry;
}
return NULL;
}
/*
* find a buffer format based on its uuid
*/
static pfm_buffer_fmt_t *
pfm_find_buffer_fmt(pfm_uuid_t uuid)
{
pfm_buffer_fmt_t * fmt;
spin_lock(&pfm_buffer_fmt_lock);
fmt = __pfm_find_buffer_fmt(uuid);
spin_unlock(&pfm_buffer_fmt_lock);
return fmt;
}
int
pfm_register_buffer_fmt(pfm_buffer_fmt_t *fmt)
{
int ret = 0;
/* some sanity checks */
if (fmt == NULL || fmt->fmt_name == NULL) return -EINVAL;
/* we need at least a handler */
if (fmt->fmt_handler == NULL) return -EINVAL;
/*
* XXX: need check validity of fmt_arg_size
*/
spin_lock(&pfm_buffer_fmt_lock);
if (__pfm_find_buffer_fmt(fmt->fmt_uuid)) {
printk(KERN_ERR "perfmon: duplicate sampling format: %s\n", fmt->fmt_name);
ret = -EBUSY;
goto out;
}
list_add(&fmt->fmt_list, &pfm_buffer_fmt_list);
printk(KERN_INFO "perfmon: added sampling format %s\n", fmt->fmt_name);
out:
spin_unlock(&pfm_buffer_fmt_lock);
return ret;
}
EXPORT_SYMBOL(pfm_register_buffer_fmt);
int
pfm_unregister_buffer_fmt(pfm_uuid_t uuid)
{
pfm_buffer_fmt_t *fmt;
int ret = 0;
spin_lock(&pfm_buffer_fmt_lock);
fmt = __pfm_find_buffer_fmt(uuid);
if (!fmt) {
printk(KERN_ERR "perfmon: cannot unregister format, not found\n");
ret = -EINVAL;
goto out;
}
list_del_init(&fmt->fmt_list);
printk(KERN_INFO "perfmon: removed sampling format: %s\n", fmt->fmt_name);
out:
spin_unlock(&pfm_buffer_fmt_lock);
return ret;
}
EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
static int
pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu)
{
unsigned long flags;
/*
* validity checks on cpu_mask have been done upstream
*/
LOCK_PFS(flags);
DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
if (is_syswide) {
/*
* cannot mix system wide and per-task sessions
*/
if (pfm_sessions.pfs_task_sessions > 0UL) {
DPRINT(("system wide not possible, %u conflicting task_sessions\n",
pfm_sessions.pfs_task_sessions));
goto abort;
}
if (pfm_sessions.pfs_sys_session[cpu]) goto error_conflict;
DPRINT(("reserving system wide session on CPU%u currently on CPU%u\n", cpu, smp_processor_id()));
pfm_sessions.pfs_sys_session[cpu] = task;
pfm_sessions.pfs_sys_sessions++ ;
} else {
if (pfm_sessions.pfs_sys_sessions) goto abort;
pfm_sessions.pfs_task_sessions++;
}
DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
/*
* Force idle() into poll mode
*/
cpu_idle_poll_ctrl(true);
UNLOCK_PFS(flags);
return 0;
error_conflict:
DPRINT(("system wide not possible, conflicting session [%d] on CPU%d\n",
task_pid_nr(pfm_sessions.pfs_sys_session[cpu]),
cpu));
abort:
UNLOCK_PFS(flags);
return -EBUSY;
}
static int
pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu)
{
unsigned long flags;
/*
* validity checks on cpu_mask have been done upstream
*/
LOCK_PFS(flags);
DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
if (is_syswide) {
pfm_sessions.pfs_sys_session[cpu] = NULL;
/*
* would not work with perfmon+more than one bit in cpu_mask
*/
if (ctx && ctx->ctx_fl_using_dbreg) {
if (pfm_sessions.pfs_sys_use_dbregs == 0) {
printk(KERN_ERR "perfmon: invalid release for ctx %p sys_use_dbregs=0\n", ctx);
} else {
pfm_sessions.pfs_sys_use_dbregs--;
}
}
pfm_sessions.pfs_sys_sessions--;
} else {
pfm_sessions.pfs_task_sessions--;
}
DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
/* Undo forced polling. Last session reenables pal_halt */
cpu_idle_poll_ctrl(false);
UNLOCK_PFS(flags);
return 0;
}
/*
* removes virtual mapping of the sampling buffer.
* IMPORTANT: cannot be called with interrupts disable, e.g. inside
* a PROTECT_CTX() section.
*/
static int
pfm_remove_smpl_mapping(void *vaddr, unsigned long size)
{
struct task_struct *task = current;
int r;
/* sanity checks */
if (task->mm == NULL || size == 0UL || vaddr == NULL) {
printk(KERN_ERR "perfmon: pfm_remove_smpl_mapping [%d] invalid context mm=%p\n", task_pid_nr(task), task->mm);
return -EINVAL;
}
DPRINT(("smpl_vaddr=%p size=%lu\n", vaddr, size));
/*
* does the actual unmapping
*/
r = vm_munmap((unsigned long)vaddr, size);
if (r !=0) {
printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
}
DPRINT(("do_unmap(%p, %lu)=%d\n", vaddr, size, r));
return 0;
}
/*
* free actual physical storage used by sampling buffer
*/
#if 0
static int
pfm_free_smpl_buffer(pfm_context_t *ctx)
{
pfm_buffer_fmt_t *fmt;
if (ctx->ctx_smpl_hdr == NULL) goto invalid_free;
/*
* we won't use the buffer format anymore
*/
fmt = ctx->ctx_buf_fmt;
DPRINT(("sampling buffer @%p size %lu vaddr=%p\n",
ctx->ctx_smpl_hdr,
ctx->ctx_smpl_size,
ctx->ctx_smpl_vaddr));
pfm_buf_fmt_exit(fmt, current, NULL, NULL);
/*
* free the buffer
*/
pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);
ctx->ctx_smpl_hdr = NULL;
ctx->ctx_smpl_size = 0UL;
return 0;
invalid_free:
printk(KERN_ERR "perfmon: pfm_free_smpl_buffer [%d] no buffer\n", task_pid_nr(current));
return -EINVAL;
}
#endif
static inline void
pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt)
{
if (fmt == NULL) return;
pfm_buf_fmt_exit(fmt, current, NULL, NULL);
}
/*
* pfmfs should _never_ be mounted by userland - too much of security hassle,
* no real gain from having the whole whorehouse mounted. So we don't need
* any operations on the root directory. However, we need a non-trivial
* d_name - pfm: will go nicely and kill the special-casing in procfs.
*/
static struct vfsmount *pfmfs_mnt __read_mostly;
static int __init
init_pfm_fs(void)
{
int err = register_filesystem(&pfm_fs_type);
if (!err) {
pfmfs_mnt = kern_mount(&pfm_fs_type);
err = PTR_ERR(pfmfs_mnt);
if (IS_ERR(pfmfs_mnt))
unregister_filesystem(&pfm_fs_type);
else
err = 0;
}
return err;
}
static ssize_t
pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
{
pfm_context_t *ctx;
pfm_msg_t *msg;
ssize_t ret;
unsigned long flags;
DECLARE_WAITQUEUE(wait, current);
if (PFM_IS_FILE(filp) == 0) {
printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
return -EINVAL;
}
ctx = filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_read: NULL ctx [%d]\n", task_pid_nr(current));
return -EINVAL;
}
/*
* check even when there is no message
*/
if (size < sizeof(pfm_msg_t)) {
DPRINT(("message is too small ctx=%p (>=%ld)\n", ctx, sizeof(pfm_msg_t)));
return -EINVAL;
}
PROTECT_CTX(ctx, flags);
/*
* put ourselves on the wait queue
*/
add_wait_queue(&ctx->ctx_msgq_wait, &wait);
for(;;) {
/*
* check wait queue
*/
set_current_state(TASK_INTERRUPTIBLE);
DPRINT(("head=%d tail=%d\n", ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
ret = 0;
if(PFM_CTXQ_EMPTY(ctx) == 0) break;
UNPROTECT_CTX(ctx, flags);
/*
* check non-blocking read
*/
ret = -EAGAIN;
if(filp->f_flags & O_NONBLOCK) break;
/*
* check pending signals
*/
if(signal_pending(current)) {
ret = -EINTR;
break;
}
/*
* no message, so wait
*/
schedule();
PROTECT_CTX(ctx, flags);
}
DPRINT(("[%d] back to running ret=%ld\n", task_pid_nr(current), ret));
set_current_state(TASK_RUNNING);
remove_wait_queue(&ctx->ctx_msgq_wait, &wait);
if (ret < 0) goto abort;
ret = -EINVAL;
msg = pfm_get_next_msg(ctx);
if (msg == NULL) {
printk(KERN_ERR "perfmon: pfm_read no msg for ctx=%p [%d]\n", ctx, task_pid_nr(current));
goto abort_locked;
}
DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
ret = -EFAULT;
if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
abort_locked:
UNPROTECT_CTX(ctx, flags);
abort:
return ret;
}
static ssize_t
pfm_write(struct file *file, const char __user *ubuf,
size_t size, loff_t *ppos)
{
DPRINT(("pfm_write called\n"));
return -EINVAL;
}
static unsigned int
pfm_poll(struct file *filp, poll_table * wait)
{
pfm_context_t *ctx;
unsigned long flags;
unsigned int mask = 0;
if (PFM_IS_FILE(filp) == 0) {
printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
return 0;
}
ctx = filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_poll: NULL ctx [%d]\n", task_pid_nr(current));
return 0;
}
DPRINT(("pfm_poll ctx_fd=%d before poll_wait\n", ctx->ctx_fd));
poll_wait(filp, &ctx->ctx_msgq_wait, wait);
PROTECT_CTX(ctx, flags);
if (PFM_CTXQ_EMPTY(ctx) == 0)
mask = POLLIN | POLLRDNORM;
UNPROTECT_CTX(ctx, flags);
DPRINT(("pfm_poll ctx_fd=%d mask=0x%x\n", ctx->ctx_fd, mask));
return mask;
}
static long
pfm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
DPRINT(("pfm_ioctl called\n"));
return -EINVAL;
}
/*
* interrupt cannot be masked when coming here
*/
static inline int
pfm_do_fasync(int fd, struct file *filp, pfm_context_t *ctx, int on)
{
int ret;
ret = fasync_helper (fd, filp, on, &ctx->ctx_async_queue);
DPRINT(("pfm_fasync called by [%d] on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
task_pid_nr(current),
fd,
on,
ctx->ctx_async_queue, ret));
return ret;
}
static int
pfm_fasync(int fd, struct file *filp, int on)
{
pfm_context_t *ctx;
int ret;
if (PFM_IS_FILE(filp) == 0) {
printk(KERN_ERR "perfmon: pfm_fasync bad magic [%d]\n", task_pid_nr(current));
return -EBADF;
}
ctx = filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_fasync NULL ctx [%d]\n", task_pid_nr(current));
return -EBADF;
}
/*
* we cannot mask interrupts during this call because this may
* may go to sleep if memory is not readily avalaible.
*
* We are protected from the conetxt disappearing by the get_fd()/put_fd()
* done in caller. Serialization of this function is ensured by caller.
*/
ret = pfm_do_fasync(fd, filp, ctx, on);
DPRINT(("pfm_fasync called on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
fd,
on,
ctx->ctx_async_queue, ret));
return ret;
}
#ifdef CONFIG_SMP
/*
* this function is exclusively called from pfm_close().
* The context is not protected at that time, nor are interrupts
* on the remote CPU. That's necessary to avoid deadlocks.
*/
static void
pfm_syswide_force_stop(void *info)
{
pfm_context_t *ctx = (pfm_context_t *)info;
struct pt_regs *regs = task_pt_regs(current);
struct task_struct *owner;
unsigned long flags;
int ret;
if (ctx->ctx_cpu != smp_processor_id()) {
printk(KERN_ERR "perfmon: pfm_syswide_force_stop for CPU%d but on CPU%d\n",
ctx->ctx_cpu,
smp_processor_id());
return;
}
owner = GET_PMU_OWNER();
if (owner != ctx->ctx_task) {
printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected owner [%d] instead of [%d]\n",
smp_processor_id(),
task_pid_nr(owner), task_pid_nr(ctx->ctx_task));
return;
}
if (GET_PMU_CTX() != ctx) {
printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected ctx %p instead of %p\n",
smp_processor_id(),
GET_PMU_CTX(), ctx);
return;
}
DPRINT(("on CPU%d forcing system wide stop for [%d]\n", smp_processor_id(), task_pid_nr(ctx->ctx_task)));
/*
* the context is already protected in pfm_close(), we simply
* need to mask interrupts to avoid a PMU interrupt race on
* this CPU
*/
local_irq_save(flags);
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
DPRINT(("context_unload returned %d\n", ret));
}
/*
* unmask interrupts, PMU interrupts are now spurious here
*/
local_irq_restore(flags);
}
static void
pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
{
int ret;
DPRINT(("calling CPU%d for cleanup\n", ctx->ctx_cpu));
ret = smp_call_function_single(ctx->ctx_cpu, pfm_syswide_force_stop, ctx, 1);
DPRINT(("called CPU%d for cleanup ret=%d\n", ctx->ctx_cpu, ret));
}
#endif /* CONFIG_SMP */
/*
* called for each close(). Partially free resources.
* When caller is self-monitoring, the context is unloaded.
*/
static int
pfm_flush(struct file *filp, fl_owner_t id)
{
pfm_context_t *ctx;
struct task_struct *task;
struct pt_regs *regs;
unsigned long flags;
unsigned long smpl_buf_size = 0UL;
void *smpl_buf_vaddr = NULL;
int state, is_system;
if (PFM_IS_FILE(filp) == 0) {
DPRINT(("bad magic for\n"));
return -EBADF;
}
ctx = filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_flush: NULL ctx [%d]\n", task_pid_nr(current));
return -EBADF;
}
/*
* remove our file from the async queue, if we use this mode.
* This can be done without the context being protected. We come
* here when the context has become unreachable by other tasks.
*
* We may still have active monitoring at this point and we may
* end up in pfm_overflow_handler(). However, fasync_helper()
* operates with interrupts disabled and it cleans up the
* queue. If the PMU handler is called prior to entering
* fasync_helper() then it will send a signal. If it is
* invoked after, it will find an empty queue and no
* signal will be sent. In both case, we are safe
*/
PROTECT_CTX(ctx, flags);
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
task = PFM_CTX_TASK(ctx);
regs = task_pt_regs(task);
DPRINT(("ctx_state=%d is_current=%d\n",
state,
task == current ? 1 : 0));
/*
* if state == UNLOADED, then task is NULL
*/
/*
* we must stop and unload because we are losing access to the context.
*/
if (task == current) {
#ifdef CONFIG_SMP
/*
* the task IS the owner but it migrated to another CPU: that's bad
* but we must handle this cleanly. Unfortunately, the kernel does
* not provide a mechanism to block migration (while the context is loaded).
*
* We need to release the resource on the ORIGINAL cpu.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
/*
* keep context protected but unmask interrupt for IPI
*/
local_irq_restore(flags);
pfm_syswide_cleanup_other_cpu(ctx);
/*
* restore interrupt masking
*/
local_irq_save(flags);
/*
* context is unloaded at this point
*/
} else
#endif /* CONFIG_SMP */
{
DPRINT(("forcing unload\n"));
/*
* stop and unload, returning with state UNLOADED
* and session unreserved.
*/
pfm_context_unload(ctx, NULL, 0, regs);
DPRINT(("ctx_state=%d\n", ctx->ctx_state));
}
}
/*
* remove virtual mapping, if any, for the calling task.
* cannot reset ctx field until last user is calling close().
*
* ctx_smpl_vaddr must never be cleared because it is needed
* by every task with access to the context
*
* When called from do_exit(), the mm context is gone already, therefore
* mm is NULL, i.e., the VMA is already gone and we do not have to
* do anything here
*/
if (ctx->ctx_smpl_vaddr && current->mm) {
smpl_buf_vaddr = ctx->ctx_smpl_vaddr;
smpl_buf_size = ctx->ctx_smpl_size;
}
UNPROTECT_CTX(ctx, flags);
/*
* if there was a mapping, then we systematically remove it
* at this point. Cannot be done inside critical section
* because some VM function reenables interrupts.
*
*/
if (smpl_buf_vaddr) pfm_remove_smpl_mapping(smpl_buf_vaddr, smpl_buf_size);
return 0;
}
/*
* called either on explicit close() or from exit_files().
* Only the LAST user of the file gets to this point, i.e., it is
* called only ONCE.
*
* IMPORTANT: we get called ONLY when the refcnt on the file gets to zero
* (fput()),i.e, last task to access the file. Nobody else can access the
* file at this point.
*
* When called from exit_files(), the VMA has been freed because exit_mm()
* is executed before exit_files().
*
* When called from exit_files(), the current task is not yet ZOMBIE but we
* flush the PMU state to the context.
*/
static int
pfm_close(struct inode *inode, struct file *filp)
{
pfm_context_t *ctx;
struct task_struct *task;
struct pt_regs *regs;
DECLARE_WAITQUEUE(wait, current);
unsigned long flags;
unsigned long smpl_buf_size = 0UL;
void *smpl_buf_addr = NULL;
int free_possible = 1;
int state, is_system;
DPRINT(("pfm_close called private=%p\n", filp->private_data));
if (PFM_IS_FILE(filp) == 0) {
DPRINT(("bad magic\n"));
return -EBADF;
}
ctx = filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_close: NULL ctx [%d]\n", task_pid_nr(current));
return -EBADF;
}
PROTECT_CTX(ctx, flags);
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
task = PFM_CTX_TASK(ctx);
regs = task_pt_regs(task);
DPRINT(("ctx_state=%d is_current=%d\n",
state,
task == current ? 1 : 0));
/*
* if task == current, then pfm_flush() unloaded the context
*/
if (state == PFM_CTX_UNLOADED) goto doit;
/*
* context is loaded/masked and task != current, we need to
* either force an unload or go zombie
*/
/*
* The task is currently blocked or will block after an overflow.
* we must force it to wakeup to get out of the
* MASKED state and transition to the unloaded state by itself.
*
* This situation is only possible for per-task mode
*/
if (state == PFM_CTX_MASKED && CTX_OVFL_NOBLOCK(ctx) == 0) {
/*
* set a "partial" zombie state to be checked
* upon return from down() in pfm_handle_work().
*
* We cannot use the ZOMBIE state, because it is checked
* by pfm_load_regs() which is called upon wakeup from down().
* In such case, it would free the context and then we would
* return to pfm_handle_work() which would access the
* stale context. Instead, we set a flag invisible to pfm_load_regs()
* but visible to pfm_handle_work().
*
* For some window of time, we have a zombie context with
* ctx_state = MASKED and not ZOMBIE
*/
ctx->ctx_fl_going_zombie = 1;
/*
* force task to wake up from MASKED state
*/
complete(&ctx->ctx_restart_done);
DPRINT(("waking up ctx_state=%d\n", state));
/*
* put ourself to sleep waiting for the other
* task to report completion
*
* the context is protected by mutex, therefore there
* is no risk of being notified of completion before
* begin actually on the waitq.
*/
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&ctx->ctx_zombieq, &wait);
UNPROTECT_CTX(ctx, flags);
/*
* XXX: check for signals :
* - ok for explicit close
* - not ok when coming from exit_files()
*/
schedule();
PROTECT_CTX(ctx, flags);
remove_wait_queue(&ctx->ctx_zombieq, &wait);
set_current_state(TASK_RUNNING);
/*
* context is unloaded at this point
*/
DPRINT(("after zombie wakeup ctx_state=%d for\n", state));
}
else if (task != current) {
#ifdef CONFIG_SMP
/*
* switch context to zombie state
*/
ctx->ctx_state = PFM_CTX_ZOMBIE;
DPRINT(("zombie ctx for [%d]\n", task_pid_nr(task)));
/*
* cannot free the context on the spot. deferred until
* the task notices the ZOMBIE state
*/
free_possible = 0;
#else
pfm_context_unload(ctx, NULL, 0, regs);
#endif
}
doit:
/* reload state, may have changed during opening of critical section */
state = ctx->ctx_state;
/*
* the context is still attached to a task (possibly current)
* we cannot destroy it right now
*/
/*
* we must free the sampling buffer right here because
* we cannot rely on it being cleaned up later by the
* monitored task. It is not possible to free vmalloc'ed
* memory in pfm_load_regs(). Instead, we remove the buffer
* now. should there be subsequent PMU overflow originally
* meant for sampling, the will be converted to spurious
* and that's fine because the monitoring tools is gone anyway.
*/
if (ctx->ctx_smpl_hdr) {
smpl_buf_addr = ctx->ctx_smpl_hdr;
smpl_buf_size = ctx->ctx_smpl_size;
/* no more sampling */
ctx->ctx_smpl_hdr = NULL;
ctx->ctx_fl_is_sampling = 0;
}
DPRINT(("ctx_state=%d free_possible=%d addr=%p size=%lu\n",
state,
free_possible,
smpl_buf_addr,
smpl_buf_size));
if (smpl_buf_addr) pfm_exit_smpl_buffer(ctx->ctx_buf_fmt);
/*
* UNLOADED that the session has already been unreserved.
*/
if (state == PFM_CTX_ZOMBIE) {
pfm_unreserve_session(ctx, ctx->ctx_fl_system , ctx->ctx_cpu);
}
/*
* disconnect file descriptor from context must be done
* before we unlock.
*/
filp->private_data = NULL;
/*
* if we free on the spot, the context is now completely unreachable
* from the callers side. The monitored task side is also cut, so we
* can freely cut.
*
* If we have a deferred free, only the caller side is disconnected.
*/
UNPROTECT_CTX(ctx, flags);
/*
* All memory free operations (especially for vmalloc'ed memory)
* MUST be done with interrupts ENABLED.
*/
if (smpl_buf_addr) pfm_rvfree(smpl_buf_addr, smpl_buf_size);
/*
* return the memory used by the context
*/
if (free_possible) pfm_context_free(ctx);
return 0;
}
static int
pfm_no_open(struct inode *irrelevant, struct file *dontcare)
{
DPRINT(("pfm_no_open called\n"));
return -ENXIO;
}
static const struct file_operations pfm_file_ops = {
.llseek = no_llseek,
.read = pfm_read,
.write = pfm_write,
.poll = pfm_poll,
.unlocked_ioctl = pfm_ioctl,
.open = pfm_no_open, /* special open code to disallow open via /proc */
.fasync = pfm_fasync,
.release = pfm_close,
.flush = pfm_flush
};
static int
pfmfs_delete_dentry(const struct dentry *dentry)
{
return 1;
}
static char *pfmfs_dname(struct dentry *dentry, char *buffer, int buflen)
{
return dynamic_dname(dentry, buffer, buflen, "pfm:[%lu]",
dentry->d_inode->i_ino);
}
static const struct dentry_operations pfmfs_dentry_operations = {
.d_delete = pfmfs_delete_dentry,
.d_dname = pfmfs_dname,
};
static struct file *
pfm_alloc_file(pfm_context_t *ctx)
{
struct file *file;
struct inode *inode;
struct path path;
struct qstr this = { .name = "" };
/*
* allocate a new inode
*/
inode = new_inode(pfmfs_mnt->mnt_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
DPRINT(("new inode ino=%ld @%p\n", inode->i_ino, inode));
inode->i_mode = S_IFCHR|S_IRUGO;
inode->i_uid = current_fsuid();
inode->i_gid = current_fsgid();
/*
* allocate a new dcache entry
*/
path.dentry = d_alloc(pfmfs_mnt->mnt_root, &this);
if (!path.dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
path.mnt = mntget(pfmfs_mnt);
d_add(path.dentry, inode);
file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
if (IS_ERR(file)) {
path_put(&path);
return file;
}
file->f_flags = O_RDONLY;
file->private_data = ctx;
return file;
}
static int
pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long addr, unsigned long size)
{
DPRINT(("CPU%d buf=0x%lx addr=0x%lx size=%ld\n", smp_processor_id(), buf, addr, size));
while (size > 0) {
unsigned long pfn = ia64_tpa(buf) >> PAGE_SHIFT;
if (remap_pfn_range(vma, addr, pfn, PAGE_SIZE, PAGE_READONLY))
return -ENOMEM;
addr += PAGE_SIZE;
buf += PAGE_SIZE;
size -= PAGE_SIZE;
}
return 0;
}
/*
* allocate a sampling buffer and remaps it into the user address space of the task
*/
static int
pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr)
{
struct mm_struct *mm = task->mm;
struct vm_area_struct *vma = NULL;
unsigned long size;
void *smpl_buf;
/*
* the fixed header + requested size and align to page boundary
*/
size = PAGE_ALIGN(rsize);
DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
/*
* check requested size to avoid Denial-of-service attacks
* XXX: may have to refine this test
* Check against address space limit.
*
* if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
* return -ENOMEM;
*/
if (size > task_rlimit(task, RLIMIT_MEMLOCK))
return -ENOMEM;
/*
* We do the easy to undo allocations first.
*
* pfm_rvmalloc(), clears the buffer, so there is no leak
*/
smpl_buf = pfm_rvmalloc(size);
if (smpl_buf == NULL) {
DPRINT(("Can't allocate sampling buffer\n"));
return -ENOMEM;
}
DPRINT(("smpl_buf @%p\n", smpl_buf));
/* allocate vma */
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma) {
DPRINT(("Cannot allocate vma\n"));
goto error_kmem;
}
INIT_LIST_HEAD(&vma->anon_vma_chain);
/*
* partially initialize the vma for the sampling buffer
*/
vma->vm_mm = mm;
vma->vm_file = get_file(filp);
vma->vm_flags = VM_READ|VM_MAYREAD|VM_DONTEXPAND|VM_DONTDUMP;
vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */
/*
* Now we have everything we need and we can initialize
* and connect all the data structures
*/
ctx->ctx_smpl_hdr = smpl_buf;
ctx->ctx_smpl_size = size; /* aligned size */
/*
* Let's do the difficult operations next.
*
* now we atomically find some area in the address space and
* remap the buffer in it.
*/
down_write(&task->mm->mmap_sem);
/* find some free area in address space, must have mmap sem held */
vma->vm_start = get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS);
if (IS_ERR_VALUE(vma->vm_start)) {
DPRINT(("Cannot find unmapped area for size %ld\n", size));
up_write(&task->mm->mmap_sem);
goto error;
}
vma->vm_end = vma->vm_start + size;
vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
DPRINT(("aligned size=%ld, hdr=%p mapped @0x%lx\n", size, ctx->ctx_smpl_hdr, vma->vm_start));
/* can only be applied to current task, need to have the mm semaphore held when called */
if (pfm_remap_buffer(vma, (unsigned long)smpl_buf, vma->vm_start, size)) {
DPRINT(("Can't remap buffer\n"));
up_write(&task->mm->mmap_sem);
goto error;
}
/*
* now insert the vma in the vm list for the process, must be
* done with mmap lock held
*/
insert_vm_struct(mm, vma);
vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file,
vma_pages(vma));
up_write(&task->mm->mmap_sem);
/*
* keep track of user level virtual address
*/
ctx->ctx_smpl_vaddr = (void *)vma->vm_start;
*(unsigned long *)user_vaddr = vma->vm_start;
return 0;
error:
kmem_cache_free(vm_area_cachep, vma);
error_kmem:
pfm_rvfree(smpl_buf, size);
return -ENOMEM;
}
/*
* XXX: do something better here
*/
static int
pfm_bad_permissions(struct task_struct *task)
{
const struct cred *tcred;
kuid_t uid = current_uid();
kgid_t gid = current_gid();
int ret;
rcu_read_lock();
tcred = __task_cred(task);
/* inspired by ptrace_attach() */
DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n",
from_kuid(&init_user_ns, uid),
from_kgid(&init_user_ns, gid),
from_kuid(&init_user_ns, tcred->euid),
from_kuid(&init_user_ns, tcred->suid),
from_kuid(&init_user_ns, tcred->uid),
from_kgid(&init_user_ns, tcred->egid),
from_kgid(&init_user_ns, tcred->sgid)));
ret = ((!uid_eq(uid, tcred->euid))
|| (!uid_eq(uid, tcred->suid))
|| (!uid_eq(uid, tcred->uid))
|| (!gid_eq(gid, tcred->egid))
|| (!gid_eq(gid, tcred->sgid))
|| (!gid_eq(gid, tcred->gid))) && !capable(CAP_SYS_PTRACE);
rcu_read_unlock();
return ret;
}
static int
pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx)
{
int ctx_flags;
/* valid signal */
ctx_flags = pfx->ctx_flags;
if (ctx_flags & PFM_FL_SYSTEM_WIDE) {
/*
* cannot block in this mode
*/
if (ctx_flags & PFM_FL_NOTIFY_BLOCK) {
DPRINT(("cannot use blocking mode when in system wide monitoring\n"));
return -EINVAL;
}
} else {
}
/* probably more to add here */
return 0;
}
static int
pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags,
unsigned int cpu, pfarg_context_t *arg)
{
pfm_buffer_fmt_t *fmt = NULL;
unsigned long size = 0UL;
void *uaddr = NULL;
void *fmt_arg = NULL;
int ret = 0;
#define PFM_CTXARG_BUF_ARG(a) (pfm_buffer_fmt_t *)(a+1)
/* invoke and lock buffer format, if found */
fmt = pfm_find_buffer_fmt(arg->ctx_smpl_buf_id);
if (fmt == NULL) {
DPRINT(("[%d] cannot find buffer format\n", task_pid_nr(task)));
return -EINVAL;
}
/*
* buffer argument MUST be contiguous to pfarg_context_t
*/
if (fmt->fmt_arg_size) fmt_arg = PFM_CTXARG_BUF_ARG(arg);
ret = pfm_buf_fmt_validate(fmt, task, ctx_flags, cpu, fmt_arg);
DPRINT(("[%d] after validate(0x%x,%d,%p)=%d\n", task_pid_nr(task), ctx_flags, cpu, fmt_arg, ret));
if (ret) goto error;
/* link buffer format and context */
ctx->ctx_buf_fmt = fmt;
ctx->ctx_fl_is_sampling = 1; /* assume record() is defined */
/*
* check if buffer format wants to use perfmon buffer allocation/mapping service
*/
ret = pfm_buf_fmt_getsize(fmt, task, ctx_flags, cpu, fmt_arg, &size);
if (ret) goto error;
if (size) {
/*
* buffer is always remapped into the caller's address space
*/
ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr);
if (ret) goto error;
/* keep track of user address of buffer */
arg->ctx_smpl_vaddr = uaddr;
}
ret = pfm_buf_fmt_init(fmt, task, ctx->ctx_smpl_hdr, ctx_flags, cpu, fmt_arg);
error:
return ret;
}
static void
pfm_reset_pmu_state(pfm_context_t *ctx)
{
int i;
/*
* install reset values for PMC.
*/
for (i=1; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_IMPL(i) == 0) continue;
ctx->ctx_pmcs[i] = PMC_DFL_VAL(i);
DPRINT(("pmc[%d]=0x%lx\n", i, ctx->ctx_pmcs[i]));
}
/*
* PMD registers are set to 0UL when the context in memset()
*/
/*
* On context switched restore, we must restore ALL pmc and ALL pmd even
* when they are not actively used by the task. In UP, the incoming process
* may otherwise pick up left over PMC, PMD state from the previous process.
* As opposed to PMD, stale PMC can cause harm to the incoming
* process because they may change what is being measured.
* Therefore, we must systematically reinstall the entire
* PMC state. In SMP, the same thing is possible on the
* same CPU but also on between 2 CPUs.
*
* The problem with PMD is information leaking especially
* to user level when psr.sp=0
*
* There is unfortunately no easy way to avoid this problem
* on either UP or SMP. This definitively slows down the
* pfm_load_regs() function.
*/
/*
* bitmask of all PMCs accessible to this context
*
* PMC0 is treated differently.
*/
ctx->ctx_all_pmcs[0] = pmu_conf->impl_pmcs[0] & ~0x1;
/*
* bitmask of all PMDs that are accessible to this context
*/
ctx->ctx_all_pmds[0] = pmu_conf->impl_pmds[0];
DPRINT(("<%d> all_pmcs=0x%lx all_pmds=0x%lx\n", ctx->ctx_fd, ctx->ctx_all_pmcs[0],ctx->ctx_all_pmds[0]));
/*
* useful in case of re-enable after disable
*/
ctx->ctx_used_ibrs[0] = 0UL;
ctx->ctx_used_dbrs[0] = 0UL;
}
static int
pfm_ctx_getsize(void *arg, size_t *sz)
{
pfarg_context_t *req = (pfarg_context_t *)arg;
pfm_buffer_fmt_t *fmt;
*sz = 0;
if (!pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) return 0;
fmt = pfm_find_buffer_fmt(req->ctx_smpl_buf_id);
if (fmt == NULL) {
DPRINT(("cannot find buffer format\n"));
return -EINVAL;
}
/* get just enough to copy in user parameters */
*sz = fmt->fmt_arg_size;
DPRINT(("arg_size=%lu\n", *sz));
return 0;
}
/*
* cannot attach if :
* - kernel task
* - task not owned by caller
* - task incompatible with context mode
*/
static int
pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
{
/*
* no kernel task or task not owner by caller
*/
if (task->mm == NULL) {
DPRINT(("task [%d] has not memory context (kernel thread)\n", task_pid_nr(task)));
return -EPERM;
}
if (pfm_bad_permissions(task)) {
DPRINT(("no permission to attach to [%d]\n", task_pid_nr(task)));
return -EPERM;
}
/*
* cannot block in self-monitoring mode
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && task == current) {
DPRINT(("cannot load a blocking context on self for [%d]\n", task_pid_nr(task)));
return -EINVAL;
}
if (task->exit_state == EXIT_ZOMBIE) {
DPRINT(("cannot attach to zombie task [%d]\n", task_pid_nr(task)));
return -EBUSY;
}
/*
* always ok for self
*/
if (task == current) return 0;
if (!task_is_stopped_or_traced(task)) {
DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
return -EBUSY;
}
/*
* make sure the task is off any CPU
*/
wait_task_inactive(task, 0);
/* more to come... */
return 0;
}
static int
pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
{
struct task_struct *p = current;
int ret;
/* XXX: need to add more checks here */
if (pid < 2) return -EPERM;
if (pid != task_pid_vnr(current)) {
read_lock(&tasklist_lock);
p = find_task_by_vpid(pid);
/* make sure task cannot go away while we operate on it */
if (p) get_task_struct(p);
read_unlock(&tasklist_lock);
if (p == NULL) return -ESRCH;
}
ret = pfm_task_incompatible(ctx, p);
if (ret == 0) {
*task = p;
} else if (p != current) {
pfm_put_task(p);
}
return ret;
}
static int
pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
pfarg_context_t *req = (pfarg_context_t *)arg;
struct file *filp;
struct path path;
int ctx_flags;
int fd;
int ret;
/* let's check the arguments first */
ret = pfarg_is_sane(current, req);
if (ret < 0)
return ret;
ctx_flags = req->ctx_flags;
ret = -ENOMEM;
fd = get_unused_fd();
if (fd < 0)
return fd;
ctx = pfm_context_alloc(ctx_flags);
if (!ctx)
goto error;
filp = pfm_alloc_file(ctx);
if (IS_ERR(filp)) {
ret = PTR_ERR(filp);
goto error_file;
}
req->ctx_fd = ctx->ctx_fd = fd;
/*
* does the user want to sample?
*/
if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) {
ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req);
if (ret)
goto buffer_error;
}
DPRINT(("ctx=%p flags=0x%x system=%d notify_block=%d excl_idle=%d no_msg=%d ctx_fd=%d\n",
ctx,
ctx_flags,
ctx->ctx_fl_system,
ctx->ctx_fl_block,
ctx->ctx_fl_excl_idle,
ctx->ctx_fl_no_msg,
ctx->ctx_fd));
/*
* initialize soft PMU state
*/
pfm_reset_pmu_state(ctx);
fd_install(fd, filp);
return 0;
buffer_error:
path = filp->f_path;
put_filp(filp);
path_put(&path);
if (ctx->ctx_buf_fmt) {
pfm_buf_fmt_exit(ctx->ctx_buf_fmt, current, NULL, regs);
}
error_file:
pfm_context_free(ctx);
error:
put_unused_fd(fd);
return ret;
}
static inline unsigned long
pfm_new_counter_value (pfm_counter_t *reg, int is_long_reset)
{
unsigned long val = is_long_reset ? reg->long_reset : reg->short_reset;
unsigned long new_seed, old_seed = reg->seed, mask = reg->mask;
extern unsigned long carta_random32 (unsigned long seed);
if (reg->flags & PFM_REGFL_RANDOM) {
new_seed = carta_random32(old_seed);
val -= (old_seed & mask); /* counter values are negative numbers! */
if ((mask >> 32) != 0)
/* construct a full 64-bit random value: */
new_seed |= carta_random32(old_seed >> 32) << 32;
reg->seed = new_seed;
}
reg->lval = val;
return val;
}
static void
pfm_reset_regs_masked(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
{
unsigned long mask = ovfl_regs[0];
unsigned long reset_others = 0UL;
unsigned long val;
int i;
/*
* now restore reset value on sampling overflowed counters
*/
mask >>= PMU_FIRST_COUNTER;
for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
if ((mask & 0x1UL) == 0UL) continue;
ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
}
/*
* Now take care of resetting the other registers
*/
for(i = 0; reset_others; i++, reset_others >>= 1) {
if ((reset_others & 0x1) == 0) continue;
ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
is_long_reset ? "long" : "short", i, val));
}
}
static void
pfm_reset_regs(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
{
unsigned long mask = ovfl_regs[0];
unsigned long reset_others = 0UL;
unsigned long val;
int i;
DPRINT_ovfl(("ovfl_regs=0x%lx is_long_reset=%d\n", ovfl_regs[0], is_long_reset));
if (ctx->ctx_state == PFM_CTX_MASKED) {
pfm_reset_regs_masked(ctx, ovfl_regs, is_long_reset);
return;
}
/*
* now restore reset value on sampling overflowed counters
*/
mask >>= PMU_FIRST_COUNTER;
for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
if ((mask & 0x1UL) == 0UL) continue;
val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
pfm_write_soft_counter(ctx, i, val);
}
/*
* Now take care of resetting the other registers
*/
for(i = 0; reset_others; i++, reset_others >>= 1) {
if ((reset_others & 0x1) == 0) continue;
val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
if (PMD_IS_COUNTING(i)) {
pfm_write_soft_counter(ctx, i, val);
} else {
ia64_set_pmd(i, val);
}
DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
is_long_reset ? "long" : "short", i, val));
}
ia64_srlz_d();
}
static int
pfm_write_pmcs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned long value, pmc_pm;
unsigned long smpl_pmds, reset_pmds, impl_pmds;
unsigned int cnum, reg_flags, flags, pmc_type;
int i, can_access_pmu = 0, is_loaded, is_system, expert_mode;
int is_monitor, is_counting, state;
int ret = -EINVAL;
pfm_reg_check_t wr_func;
#define PFM_CHECK_PMC_PM(x, y, z) ((x)->ctx_fl_system ^ PMC_PM(y, z))
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
task = ctx->ctx_task;
impl_pmds = pmu_conf->impl_pmds[0];
if (state == PFM_CTX_ZOMBIE) return -EINVAL;
if (is_loaded) {
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
}
expert_mode = pfm_sysctl.expert_mode;
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
reg_flags = req->reg_flags;
value = req->reg_value;
smpl_pmds = req->reg_smpl_pmds[0];
reset_pmds = req->reg_reset_pmds[0];
flags = 0;
if (cnum >= PMU_MAX_PMCS) {
DPRINT(("pmc%u is invalid\n", cnum));
goto error;
}
pmc_type = pmu_conf->pmc_desc[cnum].type;
pmc_pm = (value >> pmu_conf->pmc_desc[cnum].pm_pos) & 0x1;
is_counting = (pmc_type & PFM_REG_COUNTING) == PFM_REG_COUNTING ? 1 : 0;
is_monitor = (pmc_type & PFM_REG_MONITOR) == PFM_REG_MONITOR ? 1 : 0;
/*
* we reject all non implemented PMC as well
* as attempts to modify PMC[0-3] which are used
* as status registers by the PMU
*/
if ((pmc_type & PFM_REG_IMPL) == 0 || (pmc_type & PFM_REG_CONTROL) == PFM_REG_CONTROL) {
DPRINT(("pmc%u is unimplemented or no-access pmc_type=%x\n", cnum, pmc_type));
goto error;
}
wr_func = pmu_conf->pmc_desc[cnum].write_check;
/*
* If the PMC is a monitor, then if the value is not the default:
* - system-wide session: PMCx.pm=1 (privileged monitor)
* - per-task : PMCx.pm=0 (user monitor)
*/
if (is_monitor && value != PMC_DFL_VAL(cnum) && is_system ^ pmc_pm) {
DPRINT(("pmc%u pmc_pm=%lu is_system=%d\n",
cnum,
pmc_pm,
is_system));
goto error;
}
if (is_counting) {
/*
* enforce generation of overflow interrupt. Necessary on all
* CPUs.
*/
value |= 1 << PMU_PMC_OI;
if (reg_flags & PFM_REGFL_OVFL_NOTIFY) {
flags |= PFM_REGFL_OVFL_NOTIFY;
}
if (reg_flags & PFM_REGFL_RANDOM) flags |= PFM_REGFL_RANDOM;
/* verify validity of smpl_pmds */
if ((smpl_pmds & impl_pmds) != smpl_pmds) {
DPRINT(("invalid smpl_pmds 0x%lx for pmc%u\n", smpl_pmds, cnum));
goto error;
}
/* verify validity of reset_pmds */
if ((reset_pmds & impl_pmds) != reset_pmds) {
DPRINT(("invalid reset_pmds 0x%lx for pmc%u\n", reset_pmds, cnum));
goto error;
}
} else {
if (reg_flags & (PFM_REGFL_OVFL_NOTIFY|PFM_REGFL_RANDOM)) {
DPRINT(("cannot set ovfl_notify or random on pmc%u\n", cnum));
goto error;
}
/* eventid on non-counting monitors are ignored */
}
/*
* execute write checker, if any
*/
if (likely(expert_mode == 0 && wr_func)) {
ret = (*wr_func)(task, ctx, cnum, &value, regs);
if (ret) goto error;
ret = -EINVAL;
}
/*
* no error on this register
*/
PFM_REG_RETFLAG_SET(req->reg_flags, 0);
/*
* Now we commit the changes to the software state
*/
/*
* update overflow information
*/
if (is_counting) {
/*
* full flag update each time a register is programmed
*/
ctx->ctx_pmds[cnum].flags = flags;
ctx->ctx_pmds[cnum].reset_pmds[0] = reset_pmds;
ctx->ctx_pmds[cnum].smpl_pmds[0] = smpl_pmds;
ctx->ctx_pmds[cnum].eventid = req->reg_smpl_eventid;
/*
* Mark all PMDS to be accessed as used.
*
* We do not keep track of PMC because we have to
* systematically restore ALL of them.
*
* We do not update the used_monitors mask, because
* if we have not programmed them, then will be in
* a quiescent state, therefore we will not need to
* mask/restore then when context is MASKED.
*/
CTX_USED_PMD(ctx, reset_pmds);
CTX_USED_PMD(ctx, smpl_pmds);
/*
* make sure we do not try to reset on
* restart because we have established new values
*/
if (state == PFM_CTX_MASKED) ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
}
/*
* Needed in case the user does not initialize the equivalent
* PMD. Clearing is done indirectly via pfm_reset_pmu_state() so there is no
* possible leak here.
*/
CTX_USED_PMD(ctx, pmu_conf->pmc_desc[cnum].dep_pmd[0]);
/*
* keep track of the monitor PMC that we are using.
* we save the value of the pmc in ctx_pmcs[] and if
* the monitoring is not stopped for the context we also
* place it in the saved state area so that it will be
* picked up later by the context switch code.
*
* The value in ctx_pmcs[] can only be changed in pfm_write_pmcs().
*
* The value in th_pmcs[] may be modified on overflow, i.e., when
* monitoring needs to be stopped.
*/
if (is_monitor) CTX_USED_MONITOR(ctx, 1UL << cnum);
/*
* update context state
*/
ctx->ctx_pmcs[cnum] = value;
if (is_loaded) {
/*
* write thread state
*/
if (is_system == 0) ctx->th_pmcs[cnum] = value;
/*
* write hardware register if we can
*/
if (can_access_pmu) {
ia64_set_pmc(cnum, value);
}
#ifdef CONFIG_SMP
else {
/*
* per-task SMP only here
*
* we are guaranteed that the task is not running on the other CPU,
* we indicate that this PMD will need to be reloaded if the task
* is rescheduled on the CPU it ran last on.
*/
ctx->ctx_reload_pmcs[0] |= 1UL << cnum;
}
#endif
}
DPRINT(("pmc[%u]=0x%lx ld=%d apmu=%d flags=0x%x all_pmcs=0x%lx used_pmds=0x%lx eventid=%ld smpl_pmds=0x%lx reset_pmds=0x%lx reloads_pmcs=0x%lx used_monitors=0x%lx ovfl_regs=0x%lx\n",
cnum,
value,
is_loaded,
can_access_pmu,
flags,
ctx->ctx_all_pmcs[0],
ctx->ctx_used_pmds[0],
ctx->ctx_pmds[cnum].eventid,
smpl_pmds,
reset_pmds,
ctx->ctx_reload_pmcs[0],
ctx->ctx_used_monitors[0],
ctx->ctx_ovfl_regs[0]));
}
/*
* make sure the changes are visible
*/
if (can_access_pmu) ia64_srlz_d();
return 0;
error:
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
static int
pfm_write_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned long value, hw_value, ovfl_mask;
unsigned int cnum;
int i, can_access_pmu = 0, state;
int is_counting, is_loaded, is_system, expert_mode;
int ret = -EINVAL;
pfm_reg_check_t wr_func;
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
ovfl_mask = pmu_conf->ovfl_val;
task = ctx->ctx_task;
if (unlikely(state == PFM_CTX_ZOMBIE)) return -EINVAL;
/*
* on both UP and SMP, we can only write to the PMC when the task is
* the owner of the local PMU.
*/
if (likely(is_loaded)) {
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
}
expert_mode = pfm_sysctl.expert_mode;
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
value = req->reg_value;
if (!PMD_IS_IMPL(cnum)) {
DPRINT(("pmd[%u] is unimplemented or invalid\n", cnum));
goto abort_mission;
}
is_counting = PMD_IS_COUNTING(cnum);
wr_func = pmu_conf->pmd_desc[cnum].write_check;
/*
* execute write checker, if any
*/
if (unlikely(expert_mode == 0 && wr_func)) {
unsigned long v = value;
ret = (*wr_func)(task, ctx, cnum, &v, regs);
if (ret) goto abort_mission;
value = v;
ret = -EINVAL;
}
/*
* no error on this register
*/
PFM_REG_RETFLAG_SET(req->reg_flags, 0);
/*
* now commit changes to software state
*/
hw_value = value;
/*
* update virtualized (64bits) counter
*/
if (is_counting) {
/*
* write context state
*/
ctx->ctx_pmds[cnum].lval = value;
/*
* when context is load we use the split value
*/
if (is_loaded) {
hw_value = value & ovfl_mask;
value = value & ~ovfl_mask;
}
}
/*
* update reset values (not just for counters)
*/
ctx->ctx_pmds[cnum].long_reset = req->reg_long_reset;
ctx->ctx_pmds[cnum].short_reset = req->reg_short_reset;
/*
* update randomization parameters (not just for counters)
*/
ctx->ctx_pmds[cnum].seed = req->reg_random_seed;
ctx->ctx_pmds[cnum].mask = req->reg_random_mask;
/*
* update context value
*/
ctx->ctx_pmds[cnum].val = value;
/*
* Keep track of what we use
*
* We do not keep track of PMC because we have to
* systematically restore ALL of them.
*/
CTX_USED_PMD(ctx, PMD_PMD_DEP(cnum));
/*
* mark this PMD register used as well
*/
CTX_USED_PMD(ctx, RDEP(cnum));
/*
* make sure we do not try to reset on
* restart because we have established new values
*/
if (is_counting && state == PFM_CTX_MASKED) {
ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
}
if (is_loaded) {
/*
* write thread state
*/
if (is_system == 0) ctx->th_pmds[cnum] = hw_value;
/*
* write hardware register if we can
*/
if (can_access_pmu) {
ia64_set_pmd(cnum, hw_value);
} else {
#ifdef CONFIG_SMP
/*
* we are guaranteed that the task is not running on the other CPU,
* we indicate that this PMD will need to be reloaded if the task
* is rescheduled on the CPU it ran last on.
*/
ctx->ctx_reload_pmds[0] |= 1UL << cnum;
#endif
}
}
DPRINT(("pmd[%u]=0x%lx ld=%d apmu=%d, hw_value=0x%lx ctx_pmd=0x%lx short_reset=0x%lx "
"long_reset=0x%lx notify=%c seed=0x%lx mask=0x%lx used_pmds=0x%lx reset_pmds=0x%lx reload_pmds=0x%lx all_pmds=0x%lx ovfl_regs=0x%lx\n",
cnum,
value,
is_loaded,
can_access_pmu,
hw_value,
ctx->ctx_pmds[cnum].val,
ctx->ctx_pmds[cnum].short_reset,
ctx->ctx_pmds[cnum].long_reset,
PMC_OVFL_NOTIFY(ctx, cnum) ? 'Y':'N',
ctx->ctx_pmds[cnum].seed,
ctx->ctx_pmds[cnum].mask,
ctx->ctx_used_pmds[0],
ctx->ctx_pmds[cnum].reset_pmds[0],
ctx->ctx_reload_pmds[0],
ctx->ctx_all_pmds[0],
ctx->ctx_ovfl_regs[0]));
}
/*
* make changes visible
*/
if (can_access_pmu) ia64_srlz_d();
return 0;
abort_mission:
/*
* for now, we have only one possibility for error
*/
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
/*
* By the way of PROTECT_CONTEXT(), interrupts are masked while we are in this function.
* Therefore we know, we do not have to worry about the PMU overflow interrupt. If an
* interrupt is delivered during the call, it will be kept pending until we leave, making
* it appears as if it had been generated at the UNPROTECT_CONTEXT(). At least we are
* guaranteed to return consistent data to the user, it may simply be old. It is not
* trivial to treat the overflow while inside the call because you may end up in
* some module sampling buffer code causing deadlocks.
*/
static int
pfm_read_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
unsigned long val = 0UL, lval, ovfl_mask, sval;
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned int cnum, reg_flags = 0;
int i, can_access_pmu = 0, state;
int is_loaded, is_system, is_counting, expert_mode;
int ret = -EINVAL;
pfm_reg_check_t rd_func;
/*
* access is possible when loaded only for
* self-monitoring tasks or in UP mode
*/
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
ovfl_mask = pmu_conf->ovfl_val;
task = ctx->ctx_task;
if (state == PFM_CTX_ZOMBIE) return -EINVAL;
if (likely(is_loaded)) {
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
/*
* this can be true when not self-monitoring only in UP
*/
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
if (can_access_pmu) ia64_srlz_d();
}
expert_mode = pfm_sysctl.expert_mode;
DPRINT(("ld=%d apmu=%d ctx_state=%d\n",
is_loaded,
can_access_pmu,
state));
/*
* on both UP and SMP, we can only read the PMD from the hardware register when
* the task is the owner of the local PMU.
*/
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
reg_flags = req->reg_flags;
if (unlikely(!PMD_IS_IMPL(cnum))) goto error;
/*
* we can only read the register that we use. That includes
* the one we explicitly initialize AND the one we want included
* in the sampling buffer (smpl_regs).
*
* Having this restriction allows optimization in the ctxsw routine
* without compromising security (leaks)
*/
if (unlikely(!CTX_IS_USED_PMD(ctx, cnum))) goto error;
sval = ctx->ctx_pmds[cnum].val;
lval = ctx->ctx_pmds[cnum].lval;
is_counting = PMD_IS_COUNTING(cnum);
/*
* If the task is not the current one, then we check if the
* PMU state is still in the local live register due to lazy ctxsw.
* If true, then we read directly from the registers.
*/
if (can_access_pmu){
val = ia64_get_pmd(cnum);
} else {
/*
* context has been saved
* if context is zombie, then task does not exist anymore.
* In this case, we use the full value saved in the context (pfm_flush_regs()).
*/
val = is_loaded ? ctx->th_pmds[cnum] : 0UL;
}
rd_func = pmu_conf->pmd_desc[cnum].read_check;
if (is_counting) {
/*
* XXX: need to check for overflow when loaded
*/
val &= ovfl_mask;
val += sval;
}
/*
* execute read checker, if any
*/
if (unlikely(expert_mode == 0 && rd_func)) {
unsigned long v = val;
ret = (*rd_func)(ctx->ctx_task, ctx, cnum, &v, regs);
if (ret) goto error;
val = v;
ret = -EINVAL;
}
PFM_REG_RETFLAG_SET(reg_flags, 0);
DPRINT(("pmd[%u]=0x%lx\n", cnum, val));
/*
* update register return value, abort all if problem during copy.
* we only modify the reg_flags field. no check mode is fine because
* access has been verified upfront in sys_perfmonctl().
*/
req->reg_value = val;
req->reg_flags = reg_flags;
req->reg_last_reset_val = lval;
}
return 0;
error:
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
int
pfm_mod_write_pmcs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_write_pmcs(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_write_pmcs);
int
pfm_mod_read_pmds(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_read_pmds(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_read_pmds);
/*
* Only call this function when a process it trying to
* write the debug registers (reading is always allowed)
*/
int
pfm_use_debug_registers(struct task_struct *task)
{
pfm_context_t *ctx = task->thread.pfm_context;
unsigned long flags;
int ret = 0;
if (pmu_conf->use_rr_dbregs == 0) return 0;
DPRINT(("called for [%d]\n", task_pid_nr(task)));
/*
* do it only once
*/
if (task->thread.flags & IA64_THREAD_DBG_VALID) return 0;
/*
* Even on SMP, we do not need to use an atomic here because
* the only way in is via ptrace() and this is possible only when the
* process is stopped. Even in the case where the ctxsw out is not totally
* completed by the time we come here, there is no way the 'stopped' process
* could be in the middle of fiddling with the pfm_write_ibr_dbr() routine.
* So this is always safe.
*/
if (ctx && ctx->ctx_fl_using_dbreg == 1) return -1;
LOCK_PFS(flags);
/*
* We cannot allow setting breakpoints when system wide monitoring
* sessions are using the debug registers.
*/
if (pfm_sessions.pfs_sys_use_dbregs> 0)
ret = -1;
else
pfm_sessions.pfs_ptrace_use_dbregs++;
DPRINT(("ptrace_use_dbregs=%u sys_use_dbregs=%u by [%d] ret = %d\n",
pfm_sessions.pfs_ptrace_use_dbregs,
pfm_sessions.pfs_sys_use_dbregs,
task_pid_nr(task), ret));
UNLOCK_PFS(flags);
return ret;
}
/*
* This function is called for every task that exits with the
* IA64_THREAD_DBG_VALID set. This indicates a task which was
* able to use the debug registers for debugging purposes via
* ptrace(). Therefore we know it was not using them for
* performance monitoring, so we only decrement the number
* of "ptraced" debug register users to keep the count up to date
*/
int
pfm_release_debug_registers(struct task_struct *task)
{
unsigned long flags;
int ret;
if (pmu_conf->use_rr_dbregs == 0) return 0;
LOCK_PFS(flags);
if (pfm_sessions.pfs_ptrace_use_dbregs == 0) {
printk(KERN_ERR "perfmon: invalid release for [%d] ptrace_use_dbregs=0\n", task_pid_nr(task));
ret = -1;
} else {
pfm_sessions.pfs_ptrace_use_dbregs--;
ret = 0;
}
UNLOCK_PFS(flags);
return ret;
}
static int
pfm_restart(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
pfm_buffer_fmt_t *fmt;
pfm_ovfl_ctrl_t rst_ctrl;
int state, is_system;
int ret = 0;
state = ctx->ctx_state;
fmt = ctx->ctx_buf_fmt;
is_system = ctx->ctx_fl_system;
task = PFM_CTX_TASK(ctx);
switch(state) {
case PFM_CTX_MASKED:
break;
case PFM_CTX_LOADED:
if (CTX_HAS_SMPL(ctx) && fmt->fmt_restart_active) break;
/* fall through */
case PFM_CTX_UNLOADED:
case PFM_CTX_ZOMBIE:
DPRINT(("invalid state=%d\n", state));
return -EBUSY;
default:
DPRINT(("state=%d, cannot operate (no active_restart handler)\n", state));
return -EINVAL;
}
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
/* sanity check */
if (unlikely(task == NULL)) {
printk(KERN_ERR "perfmon: [%d] pfm_restart no task\n", task_pid_nr(current));
return -EINVAL;
}
if (task == current || is_system) {
fmt = ctx->ctx_buf_fmt;
DPRINT(("restarting self %d ovfl=0x%lx\n",
task_pid_nr(task),
ctx->ctx_ovfl_regs[0]));
if (CTX_HAS_SMPL(ctx)) {
prefetch(ctx->ctx_smpl_hdr);
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 0;
if (state == PFM_CTX_LOADED)
ret = pfm_buf_fmt_restart_active(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
else
ret = pfm_buf_fmt_restart(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
} else {
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 1;
}
if (ret == 0) {
if (rst_ctrl.bits.reset_ovfl_pmds)
pfm_reset_regs(ctx, ctx->ctx_ovfl_regs, PFM_PMD_LONG_RESET);
if (rst_ctrl.bits.mask_monitoring == 0) {
DPRINT(("resuming monitoring for [%d]\n", task_pid_nr(task)));
if (state == PFM_CTX_MASKED) pfm_restore_monitoring(task);
} else {
DPRINT(("keeping monitoring stopped for [%d]\n", task_pid_nr(task)));
// cannot use pfm_stop_monitoring(task, regs);
}
}
/*
* clear overflowed PMD mask to remove any stale information
*/
ctx->ctx_ovfl_regs[0] = 0UL;
/*
* back to LOADED state
*/
ctx->ctx_state = PFM_CTX_LOADED;
/*
* XXX: not really useful for self monitoring
*/
ctx->ctx_fl_can_restart = 0;
return 0;
}
/*
* restart another task
*/
/*
* When PFM_CTX_MASKED, we cannot issue a restart before the previous
* one is seen by the task.
*/
if (state == PFM_CTX_MASKED) {
if (ctx->ctx_fl_can_restart == 0) return -EINVAL;
/*
* will prevent subsequent restart before this one is
* seen by other task
*/
ctx->ctx_fl_can_restart = 0;
}
/*
* if blocking, then post the semaphore is PFM_CTX_MASKED, i.e.
* the task is blocked or on its way to block. That's the normal
* restart path. If the monitoring is not masked, then the task
* can be actively monitoring and we cannot directly intervene.
* Therefore we use the trap mechanism to catch the task and
* force it to reset the buffer/reset PMDs.
*
* if non-blocking, then we ensure that the task will go into
* pfm_handle_work() before returning to user mode.
*
* We cannot explicitly reset another task, it MUST always
* be done by the task itself. This works for system wide because
* the tool that is controlling the session is logically doing
* "self-monitoring".
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
DPRINT(("unblocking [%d]\n", task_pid_nr(task)));
complete(&ctx->ctx_restart_done);
} else {
DPRINT(("[%d] armed exit trap\n", task_pid_nr(task)));
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_RESET;
PFM_SET_WORK_PENDING(task, 1);
set_notify_resume(task);
/*
* XXX: send reschedule if task runs on another CPU
*/
}
return 0;
}
static int
pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
unsigned int m = *(unsigned int *)arg;
pfm_sysctl.debug = m == 0 ? 0 : 1;
printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
if (m == 0) {
memset(pfm_stats, 0, sizeof(pfm_stats));
for(m=0; m < NR_CPUS; m++) pfm_stats[m].pfm_ovfl_intr_cycles_min = ~0UL;
}
return 0;
}
/*
* arg can be NULL and count can be zero for this function
*/
static int
pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct thread_struct *thread = NULL;
struct task_struct *task;
pfarg_dbreg_t *req = (pfarg_dbreg_t *)arg;
unsigned long flags;
dbreg_t dbreg;
unsigned int rnum;
int first_time;
int ret = 0, state;
int i, can_access_pmu = 0;
int is_system, is_loaded;
if (pmu_conf->use_rr_dbregs == 0) return -EINVAL;
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
task = ctx->ctx_task;
if (state == PFM_CTX_ZOMBIE) return -EINVAL;
/*
* on both UP and SMP, we can only write to the PMC when the task is
* the owner of the local PMU.
*/
if (is_loaded) {
thread = &task->thread;
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
}
/*
* we do not need to check for ipsr.db because we do clear ibr.x, dbr.r, and dbr.w
* ensuring that no real breakpoint can be installed via this call.
*
* IMPORTANT: regs can be NULL in this function
*/
first_time = ctx->ctx_fl_using_dbreg == 0;
/*
* don't bother if we are loaded and task is being debugged
*/
if (is_loaded && (thread->flags & IA64_THREAD_DBG_VALID) != 0) {
DPRINT(("debug registers already in use for [%d]\n", task_pid_nr(task)));
return -EBUSY;
}
/*
* check for debug registers in system wide mode
*
* If though a check is done in pfm_context_load(),
* we must repeat it here, in case the registers are
* written after the context is loaded
*/
if (is_loaded) {
LOCK_PFS(flags);
if (first_time && is_system) {
if (pfm_sessions.pfs_ptrace_use_dbregs)
ret = -EBUSY;
else
pfm_sessions.pfs_sys_use_dbregs++;
}
UNLOCK_PFS(flags);
}
if (ret != 0) return ret;
/*
* mark ourself as user of the debug registers for
* perfmon purposes.
*/
ctx->ctx_fl_using_dbreg = 1;
/*
* clear hardware registers to make sure we don't
* pick up stale state.
*
* for a system wide session, we do not use
* thread.dbr, thread.ibr because this process
* never leaves the current CPU and the state
* is shared by all processes running on it
*/
if (first_time && can_access_pmu) {
DPRINT(("[%d] clearing ibrs, dbrs\n", task_pid_nr(task)));
for (i=0; i < pmu_conf->num_ibrs; i++) {
ia64_set_ibr(i, 0UL);
ia64_dv_serialize_instruction();
}
ia64_srlz_i();
for (i=0; i < pmu_conf->num_dbrs; i++) {
ia64_set_dbr(i, 0UL);
ia64_dv_serialize_data();
}
ia64_srlz_d();
}
/*
* Now install the values into the registers
*/
for (i = 0; i < count; i++, req++) {
rnum = req->dbreg_num;
dbreg.val = req->dbreg_value;
ret = -EINVAL;
if ((mode == PFM_CODE_RR && rnum >= PFM_NUM_IBRS) || ((mode == PFM_DATA_RR) && rnum >= PFM_NUM_DBRS)) {
DPRINT(("invalid register %u val=0x%lx mode=%d i=%d count=%d\n",
rnum, dbreg.val, mode, i, count));
goto abort_mission;
}
/*
* make sure we do not install enabled breakpoint
*/
if (rnum & 0x1) {
if (mode == PFM_CODE_RR)
dbreg.ibr.ibr_x = 0;
else
dbreg.dbr.dbr_r = dbreg.dbr.dbr_w = 0;
}
PFM_REG_RETFLAG_SET(req->dbreg_flags, 0);
/*
* Debug registers, just like PMC, can only be modified
* by a kernel call. Moreover, perfmon() access to those
* registers are centralized in this routine. The hardware
* does not modify the value of these registers, therefore,
* if we save them as they are written, we can avoid having
* to save them on context switch out. This is made possible
* by the fact that when perfmon uses debug registers, ptrace()
* won't be able to modify them concurrently.
*/
if (mode == PFM_CODE_RR) {
CTX_USED_IBR(ctx, rnum);
if (can_access_pmu) {
ia64_set_ibr(rnum, dbreg.val);
ia64_dv_serialize_instruction();
}
ctx->ctx_ibrs[rnum] = dbreg.val;
DPRINT(("write ibr%u=0x%lx used_ibrs=0x%x ld=%d apmu=%d\n",
rnum, dbreg.val, ctx->ctx_used_ibrs[0], is_loaded, can_access_pmu));
} else {
CTX_USED_DBR(ctx, rnum);
if (can_access_pmu) {
ia64_set_dbr(rnum, dbreg.val);
ia64_dv_serialize_data();
}
ctx->ctx_dbrs[rnum] = dbreg.val;
DPRINT(("write dbr%u=0x%lx used_dbrs=0x%x ld=%d apmu=%d\n",
rnum, dbreg.val, ctx->ctx_used_dbrs[0], is_loaded, can_access_pmu));
}
}
return 0;
abort_mission:
/*
* in case it was our first attempt, we undo the global modifications
*/
if (first_time) {
LOCK_PFS(flags);
if (ctx->ctx_fl_system) {
pfm_sessions.pfs_sys_use_dbregs--;
}
UNLOCK_PFS(flags);
ctx->ctx_fl_using_dbreg = 0;
}
/*
* install error return flag
*/
PFM_REG_RETFLAG_SET(req->dbreg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
static int
pfm_write_ibrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
return pfm_write_ibr_dbr(PFM_CODE_RR, ctx, arg, count, regs);
}
static int
pfm_write_dbrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
return pfm_write_ibr_dbr(PFM_DATA_RR, ctx, arg, count, regs);
}
int
pfm_mod_write_ibrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_write_ibrs(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_write_ibrs);
int
pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_write_dbrs(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_write_dbrs);
static int
pfm_get_features(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
pfarg_features_t *req = (pfarg_features_t *)arg;
req->ft_version = PFM_VERSION;
return 0;
}
static int
pfm_stop(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct pt_regs *tregs;
struct task_struct *task = PFM_CTX_TASK(ctx);
int state, is_system;
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
/*
* context must be attached to issue the stop command (includes LOADED,MASKED,ZOMBIE)
*/
if (state == PFM_CTX_UNLOADED) return -EINVAL;
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
DPRINT(("task [%d] ctx_state=%d is_system=%d\n",
task_pid_nr(PFM_CTX_TASK(ctx)),
state,
is_system));
/*
* in system mode, we need to update the PMU directly
* and the user level state of the caller, which may not
* necessarily be the creator of the context.
*/
if (is_system) {
/*
* Update local PMU first
*
* disable dcr pp
*/
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
ia64_srlz_i();
/*
* update local cpuinfo
*/
PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
/*
* stop monitoring, does srlz.i
*/
pfm_clear_psr_pp();
/*
* stop monitoring in the caller
*/
ia64_psr(regs)->pp = 0;
return 0;
}
/*
* per-task mode
*/
if (task == current) {
/* stop monitoring at kernel level */
pfm_clear_psr_up();
/*
* stop monitoring at the user level
*/
ia64_psr(regs)->up = 0;
} else {
tregs = task_pt_regs(task);
/*
* stop monitoring at the user level
*/
ia64_psr(tregs)->up = 0;
/*
* monitoring disabled in kernel at next reschedule
*/
ctx->ctx_saved_psr_up = 0;
DPRINT(("task=[%d]\n", task_pid_nr(task)));
}
return 0;
}
static int
pfm_start(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct pt_regs *tregs;
int state, is_system;
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
if (state != PFM_CTX_LOADED) return -EINVAL;
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
/*
* in system mode, we need to update the PMU directly
* and the user level state of the caller, which may not
* necessarily be the creator of the context.
*/
if (is_system) {
/*
* set user level psr.pp for the caller
*/
ia64_psr(regs)->pp = 1;
/*
* now update the local PMU and cpuinfo
*/
PFM_CPUINFO_SET(PFM_CPUINFO_DCR_PP);
/*
* start monitoring at kernel level
*/
pfm_set_psr_pp();
/* enable dcr pp */
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
ia64_srlz_i();
return 0;
}
/*
* per-process mode
*/
if (ctx->ctx_task == current) {
/* start monitoring at kernel level */
pfm_set_psr_up();
/*
* activate monitoring at user level
*/
ia64_psr(regs)->up = 1;
} else {
tregs = task_pt_regs(ctx->ctx_task);
/*
* start monitoring at the kernel level the next
* time the task is scheduled
*/
ctx->ctx_saved_psr_up = IA64_PSR_UP;
/*
* activate monitoring at user level
*/
ia64_psr(tregs)->up = 1;
}
return 0;
}
static int
pfm_get_pmc_reset(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned int cnum;
int i;
int ret = -EINVAL;
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
if (!PMC_IS_IMPL(cnum)) goto abort_mission;
req->reg_value = PMC_DFL_VAL(cnum);
PFM_REG_RETFLAG_SET(req->reg_flags, 0);
DPRINT(("pmc_reset_val pmc[%u]=0x%lx\n", cnum, req->reg_value));
}
return 0;
abort_mission:
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
static int
pfm_check_task_exist(pfm_context_t *ctx)
{
struct task_struct *g, *t;
int ret = -ESRCH;
read_lock(&tasklist_lock);
do_each_thread (g, t) {
if (t->thread.pfm_context == ctx) {
ret = 0;
goto out;
}
} while_each_thread (g, t);
out:
read_unlock(&tasklist_lock);
DPRINT(("pfm_check_task_exist: ret=%d ctx=%p\n", ret, ctx));
return ret;
}
static int
pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
struct thread_struct *thread;
struct pfm_context_t *old;
unsigned long flags;
#ifndef CONFIG_SMP
struct task_struct *owner_task = NULL;
#endif
pfarg_load_t *req = (pfarg_load_t *)arg;
unsigned long *pmcs_source, *pmds_source;
int the_cpu;
int ret = 0;
int state, is_system, set_dbregs = 0;
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
/*
* can only load from unloaded or terminated state
*/
if (state != PFM_CTX_UNLOADED) {
DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
req->load_pid,
ctx->ctx_state));
return -EBUSY;
}
DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
if (CTX_OVFL_NOBLOCK(ctx) == 0 && req->load_pid == current->pid) {
DPRINT(("cannot use blocking mode on self\n"));
return -EINVAL;
}
ret = pfm_get_task(ctx, req->load_pid, &task);
if (ret) {
DPRINT(("load_pid [%d] get_task=%d\n", req->load_pid, ret));
return ret;
}
ret = -EINVAL;
/*
* system wide is self monitoring only
*/
if (is_system && task != current) {
DPRINT(("system wide is self monitoring only load_pid=%d\n",
req->load_pid));
goto error;
}
thread = &task->thread;
ret = 0;
/*
* cannot load a context which is using range restrictions,
* into a task that is being debugged.
*/
if (ctx->ctx_fl_using_dbreg) {
if (thread->flags & IA64_THREAD_DBG_VALID) {
ret = -EBUSY;
DPRINT(("load_pid [%d] task is debugged, cannot load range restrictions\n", req->load_pid));
goto error;
}
LOCK_PFS(flags);
if (is_system) {
if (pfm_sessions.pfs_ptrace_use_dbregs) {
DPRINT(("cannot load [%d] dbregs in use\n",
task_pid_nr(task)));
ret = -EBUSY;
} else {
pfm_sessions.pfs_sys_use_dbregs++;
DPRINT(("load [%d] increased sys_use_dbreg=%u\n", task_pid_nr(task), pfm_sessions.pfs_sys_use_dbregs));
set_dbregs = 1;
}
}
UNLOCK_PFS(flags);
if (ret) goto error;
}
/*
* SMP system-wide monitoring implies self-monitoring.
*
* The programming model expects the task to
* be pinned on a CPU throughout the session.
* Here we take note of the current CPU at the
* time the context is loaded. No call from
* another CPU will be allowed.
*
* The pinning via shed_setaffinity()
* must be done by the calling task prior
* to this call.
*
* systemwide: keep track of CPU this session is supposed to run on
*/
the_cpu = ctx->ctx_cpu = smp_processor_id();
ret = -EBUSY;
/*
* now reserve the session
*/
ret = pfm_reserve_session(current, is_system, the_cpu);
if (ret) goto error;
/*
* task is necessarily stopped at this point.
*
* If the previous context was zombie, then it got removed in
* pfm_save_regs(). Therefore we should not see it here.
* If we see a context, then this is an active context
*
* XXX: needs to be atomic
*/
DPRINT(("before cmpxchg() old_ctx=%p new_ctx=%p\n",
thread->pfm_context, ctx));
ret = -EBUSY;
old = ia64_cmpxchg(acq, &thread->pfm_context, NULL, ctx, sizeof(pfm_context_t *));
if (old != NULL) {
DPRINT(("load_pid [%d] already has a context\n", req->load_pid));
goto error_unres;
}
pfm_reset_msgq(ctx);
ctx->ctx_state = PFM_CTX_LOADED;
/*
* link context to task
*/
ctx->ctx_task = task;
if (is_system) {
/*
* we load as stopped
*/
PFM_CPUINFO_SET(PFM_CPUINFO_SYST_WIDE);
PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
if (ctx->ctx_fl_excl_idle) PFM_CPUINFO_SET(PFM_CPUINFO_EXCL_IDLE);
} else {
thread->flags |= IA64_THREAD_PM_VALID;
}
/*
* propagate into thread-state
*/
pfm_copy_pmds(task, ctx);
pfm_copy_pmcs(task, ctx);
pmcs_source = ctx->th_pmcs;
pmds_source = ctx->th_pmds;
/*
* always the case for system-wide
*/
if (task == current) {
if (is_system == 0) {
/* allow user level control */
ia64_psr(regs)->sp = 0;
DPRINT(("clearing psr.sp for [%d]\n", task_pid_nr(task)));
SET_LAST_CPU(ctx, smp_processor_id());
INC_ACTIVATION();
SET_ACTIVATION(ctx);
#ifndef CONFIG_SMP
/*
* push the other task out, if any
*/
owner_task = GET_PMU_OWNER();
if (owner_task) pfm_lazy_save_regs(owner_task);
#endif
}
/*
* load all PMD from ctx to PMU (as opposed to thread state)
* restore all PMC from ctx to PMU
*/
pfm_restore_pmds(pmds_source, ctx->ctx_all_pmds[0]);
pfm_restore_pmcs(pmcs_source, ctx->ctx_all_pmcs[0]);
ctx->ctx_reload_pmcs[0] = 0UL;
ctx->ctx_reload_pmds[0] = 0UL;
/*
* guaranteed safe by earlier check against DBG_VALID
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* set new ownership
*/
SET_PMU_OWNER(task, ctx);
DPRINT(("context loaded on PMU for [%d]\n", task_pid_nr(task)));
} else {
/*
* when not current, task MUST be stopped, so this is safe
*/
regs = task_pt_regs(task);
/* force a full reload */
ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
SET_LAST_CPU(ctx, -1);
/* initial saved psr (stopped) */
ctx->ctx_saved_psr_up = 0UL;
ia64_psr(regs)->up = ia64_psr(regs)->pp = 0;
}
ret = 0;
error_unres:
if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
error:
/*
* we must undo the dbregs setting (for system-wide)
*/
if (ret && set_dbregs) {
LOCK_PFS(flags);
pfm_sessions.pfs_sys_use_dbregs--;
UNLOCK_PFS(flags);
}
/*
* release task, there is now a link with the context
*/
if (is_system == 0 && task != current) {
pfm_put_task(task);
if (ret == 0) {
ret = pfm_check_task_exist(ctx);
if (ret) {
ctx->ctx_state = PFM_CTX_UNLOADED;
ctx->ctx_task = NULL;
}
}
}
return ret;
}
/*
* in this function, we do not need to increase the use count
* for the task via get_task_struct(), because we hold the
* context lock. If the task were to disappear while having
* a context attached, it would go through pfm_exit_thread()
* which also grabs the context lock and would therefore be blocked
* until we are here.
*/
static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
static int
pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task = PFM_CTX_TASK(ctx);
struct pt_regs *tregs;
int prev_state, is_system;
int ret;
DPRINT(("ctx_state=%d task [%d]\n", ctx->ctx_state, task ? task_pid_nr(task) : -1));
prev_state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
/*
* unload only when necessary
*/
if (prev_state == PFM_CTX_UNLOADED) {
DPRINT(("ctx_state=%d, nothing to do\n", prev_state));
return 0;
}
/*
* clear psr and dcr bits
*/
ret = pfm_stop(ctx, NULL, 0, regs);
if (ret) return ret;
ctx->ctx_state = PFM_CTX_UNLOADED;
/*
* in system mode, we need to update the PMU directly
* and the user level state of the caller, which may not
* necessarily be the creator of the context.
*/
if (is_system) {
/*
* Update cpuinfo
*
* local PMU is taken care of in pfm_stop()
*/
PFM_CPUINFO_CLEAR(PFM_CPUINFO_SYST_WIDE);
PFM_CPUINFO_CLEAR(PFM_CPUINFO_EXCL_IDLE);
/*
* save PMDs in context
* release ownership
*/
pfm_flush_pmds(current, ctx);
/*
* at this point we are done with the PMU
* so we can unreserve the resource.
*/
if (prev_state != PFM_CTX_ZOMBIE)
pfm_unreserve_session(ctx, 1 , ctx->ctx_cpu);
/*
* disconnect context from task
*/
task->thread.pfm_context = NULL;
/*
* disconnect task from context
*/
ctx->ctx_task = NULL;
/*
* There is nothing more to cleanup here.
*/
return 0;
}
/*
* per-task mode
*/
tregs = task == current ? regs : task_pt_regs(task);
if (task == current) {
/*
* cancel user level control
*/
ia64_psr(regs)->sp = 1;
DPRINT(("setting psr.sp for [%d]\n", task_pid_nr(task)));
}
/*
* save PMDs to context
* release ownership
*/
pfm_flush_pmds(task, ctx);
/*
* at this point we are done with the PMU
* so we can unreserve the resource.
*
* when state was ZOMBIE, we have already unreserved.
*/
if (prev_state != PFM_CTX_ZOMBIE)
pfm_unreserve_session(ctx, 0 , ctx->ctx_cpu);
/*
* reset activation counter and psr
*/
ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
SET_LAST_CPU(ctx, -1);
/*
* PMU state will not be restored
*/
task->thread.flags &= ~IA64_THREAD_PM_VALID;
/*
* break links between context and task
*/
task->thread.pfm_context = NULL;
ctx->ctx_task = NULL;
PFM_SET_WORK_PENDING(task, 0);
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
ctx->ctx_fl_can_restart = 0;
ctx->ctx_fl_going_zombie = 0;
DPRINT(("disconnected [%d] from context\n", task_pid_nr(task)));
return 0;
}
/*
* called only from exit_thread(): task == current
* we come here only if current has a context attached (loaded or masked)
*/
void
pfm_exit_thread(struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long flags;
struct pt_regs *regs = task_pt_regs(task);
int ret, state;
int free_ok = 0;
ctx = PFM_GET_CTX(task);
PROTECT_CTX(ctx, flags);
DPRINT(("state=%d task [%d]\n", ctx->ctx_state, task_pid_nr(task)));
state = ctx->ctx_state;
switch(state) {
case PFM_CTX_UNLOADED:
/*
* only comes to this function if pfm_context is not NULL, i.e., cannot
* be in unloaded state
*/
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] ctx unloaded\n", task_pid_nr(task));
break;
case PFM_CTX_LOADED:
case PFM_CTX_MASKED:
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
}
DPRINT(("ctx unloaded for current state was %d\n", state));
pfm_end_notify_user(ctx);
break;
case PFM_CTX_ZOMBIE:
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
}
free_ok = 1;
break;
default:
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] unexpected state=%d\n", task_pid_nr(task), state);
break;
}
UNPROTECT_CTX(ctx, flags);
{ u64 psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
BUG_ON(GET_PMU_OWNER());
BUG_ON(ia64_psr(regs)->up);
BUG_ON(ia64_psr(regs)->pp);
}
/*
* All memory free operations (especially for vmalloc'ed memory)
* MUST be done with interrupts ENABLED.
*/
if (free_ok) pfm_context_free(ctx);
}
/*
* functions MUST be listed in the increasing order of their index (see permfon.h)
*/
#define PFM_CMD(name, flags, arg_count, arg_type, getsz) { name, #name, flags, arg_count, sizeof(arg_type), getsz }
#define PFM_CMD_S(name, flags) { name, #name, flags, 0, 0, NULL }
#define PFM_CMD_PCLRWS (PFM_CMD_FD|PFM_CMD_ARG_RW|PFM_CMD_STOP)
#define PFM_CMD_PCLRW (PFM_CMD_FD|PFM_CMD_ARG_RW)
#define PFM_CMD_NONE { NULL, "no-cmd", 0, 0, 0, NULL}
static pfm_cmd_desc_t pfm_cmd_tab[]={
/* 0 */PFM_CMD_NONE,
/* 1 */PFM_CMD(pfm_write_pmcs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 2 */PFM_CMD(pfm_write_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 3 */PFM_CMD(pfm_read_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 4 */PFM_CMD_S(pfm_stop, PFM_CMD_PCLRWS),
/* 5 */PFM_CMD_S(pfm_start, PFM_CMD_PCLRWS),
/* 6 */PFM_CMD_NONE,
/* 7 */PFM_CMD_NONE,
/* 8 */PFM_CMD(pfm_context_create, PFM_CMD_ARG_RW, 1, pfarg_context_t, pfm_ctx_getsize),
/* 9 */PFM_CMD_NONE,
/* 10 */PFM_CMD_S(pfm_restart, PFM_CMD_PCLRW),
/* 11 */PFM_CMD_NONE,
/* 12 */PFM_CMD(pfm_get_features, PFM_CMD_ARG_RW, 1, pfarg_features_t, NULL),
/* 13 */PFM_CMD(pfm_debug, 0, 1, unsigned int, NULL),
/* 14 */PFM_CMD_NONE,
/* 15 */PFM_CMD(pfm_get_pmc_reset, PFM_CMD_ARG_RW, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 16 */PFM_CMD(pfm_context_load, PFM_CMD_PCLRWS, 1, pfarg_load_t, NULL),
/* 17 */PFM_CMD_S(pfm_context_unload, PFM_CMD_PCLRWS),
/* 18 */PFM_CMD_NONE,
/* 19 */PFM_CMD_NONE,
/* 20 */PFM_CMD_NONE,
/* 21 */PFM_CMD_NONE,
/* 22 */PFM_CMD_NONE,
/* 23 */PFM_CMD_NONE,
/* 24 */PFM_CMD_NONE,
/* 25 */PFM_CMD_NONE,
/* 26 */PFM_CMD_NONE,
/* 27 */PFM_CMD_NONE,
/* 28 */PFM_CMD_NONE,
/* 29 */PFM_CMD_NONE,
/* 30 */PFM_CMD_NONE,
/* 31 */PFM_CMD_NONE,
/* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
/* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
};
#define PFM_CMD_COUNT (sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
static int
pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
{
struct task_struct *task;
int state, old_state;
recheck:
state = ctx->ctx_state;
task = ctx->ctx_task;
if (task == NULL) {
DPRINT(("context %d no task, state=%d\n", ctx->ctx_fd, state));
return 0;
}
DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
ctx->ctx_fd,
state,
task_pid_nr(task),
task->state, PFM_CMD_STOPPED(cmd)));
/*
* self-monitoring always ok.
*
* for system-wide the caller can either be the creator of the
* context (to one to which the context is attached to) OR
* a task running on the same CPU as the session.
*/
if (task == current || ctx->ctx_fl_system) return 0;
/*
* we are monitoring another thread
*/
switch(state) {
case PFM_CTX_UNLOADED:
/*
* if context is UNLOADED we are safe to go
*/
return 0;
case PFM_CTX_ZOMBIE:
/*
* no command can operate on a zombie context
*/
DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
return -EINVAL;
case PFM_CTX_MASKED:
/*
* PMU state has been saved to software even though
* the thread may still be running.
*/
if (cmd != PFM_UNLOAD_CONTEXT) return 0;
}
/*
* context is LOADED or MASKED. Some commands may need to have
* the task stopped.
*
* We could lift this restriction for UP but it would mean that
* the user has no guarantee the task would not run between
* two successive calls to perfmonctl(). That's probably OK.
* If this user wants to ensure the task does not run, then
* the task must be stopped.
*/
if (PFM_CMD_STOPPED(cmd)) {
if (!task_is_stopped_or_traced(task)) {
DPRINT(("[%d] task not in stopped state\n", task_pid_nr(task)));
return -EBUSY;
}
/*
* task is now stopped, wait for ctxsw out
*
* This is an interesting point in the code.
* We need to unprotect the context because
* the pfm_save_regs() routines needs to grab
* the same lock. There are danger in doing
* this because it leaves a window open for
* another task to get access to the context
* and possibly change its state. The one thing
* that is not possible is for the context to disappear
* because we are protected by the VFS layer, i.e.,
* get_fd()/put_fd().
*/
old_state = state;
UNPROTECT_CTX(ctx, flags);
wait_task_inactive(task, 0);
PROTECT_CTX(ctx, flags);
/*
* we must recheck to verify if state has changed
*/
if (ctx->ctx_state != old_state) {
DPRINT(("old_state=%d new_state=%d\n", old_state, ctx->ctx_state));
goto recheck;
}
}
return 0;
}
/*
* system-call entry point (must return long)
*/
asmlinkage long
sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
{
struct fd f = {NULL, 0};
pfm_context_t *ctx = NULL;
unsigned long flags = 0UL;
void *args_k = NULL;
long ret; /* will expand int return types */
size_t base_sz, sz, xtra_sz = 0;
int narg, completed_args = 0, call_made = 0, cmd_flags;
int (*func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
int (*getsize)(void *arg, size_t *sz);
#define PFM_MAX_ARGSIZE 4096
/*
* reject any call if perfmon was disabled at initialization
*/
if (unlikely(pmu_conf == NULL)) return -ENOSYS;
if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
DPRINT(("invalid cmd=%d\n", cmd));
return -EINVAL;
}
func = pfm_cmd_tab[cmd].cmd_func;
narg = pfm_cmd_tab[cmd].cmd_narg;
base_sz = pfm_cmd_tab[cmd].cmd_argsize;
getsize = pfm_cmd_tab[cmd].cmd_getsize;
cmd_flags = pfm_cmd_tab[cmd].cmd_flags;
if (unlikely(func == NULL)) {
DPRINT(("invalid cmd=%d\n", cmd));
return -EINVAL;
}
DPRINT(("cmd=%s idx=%d narg=0x%x argsz=%lu count=%d\n",
PFM_CMD_NAME(cmd),
cmd,
narg,
base_sz,
count));
/*
* check if number of arguments matches what the command expects
*/
if (unlikely((narg == PFM_CMD_ARG_MANY && count <= 0) || (narg > 0 && narg != count)))
return -EINVAL;
restart_args:
sz = xtra_sz + base_sz*count;
/*
* limit abuse to min page size
*/
if (unlikely(sz > PFM_MAX_ARGSIZE)) {
printk(KERN_ERR "perfmon: [%d] argument too big %lu\n", task_pid_nr(current), sz);
return -E2BIG;
}
/*
* allocate default-sized argument buffer
*/
if (likely(count && args_k == NULL)) {
args_k = kmalloc(PFM_MAX_ARGSIZE, GFP_KERNEL);
if (args_k == NULL) return -ENOMEM;
}
ret = -EFAULT;
/*
* copy arguments
*
* assume sz = 0 for command without parameters
*/
if (sz && copy_from_user(args_k, arg, sz)) {
DPRINT(("cannot copy_from_user %lu bytes @%p\n", sz, arg));
goto error_args;
}
/*
* check if command supports extra parameters
*/
if (completed_args == 0 && getsize) {
/*
* get extra parameters size (based on main argument)
*/
ret = (*getsize)(args_k, &xtra_sz);
if (ret) goto error_args;
completed_args = 1;
DPRINT(("restart_args sz=%lu xtra_sz=%lu\n", sz, xtra_sz));
/* retry if necessary */
if (likely(xtra_sz)) goto restart_args;
}
if (unlikely((cmd_flags & PFM_CMD_FD) == 0)) goto skip_fd;
ret = -EBADF;
f = fdget(fd);
if (unlikely(f.file == NULL)) {
DPRINT(("invalid fd %d\n", fd));
goto error_args;
}
if (unlikely(PFM_IS_FILE(f.file) == 0)) {
DPRINT(("fd %d not related to perfmon\n", fd));
goto error_args;
}
ctx = f.file->private_data;
if (unlikely(ctx == NULL)) {
DPRINT(("no context for fd %d\n", fd));
goto error_args;
}
prefetch(&ctx->ctx_state);
PROTECT_CTX(ctx, flags);
/*
* check task is stopped
*/
ret = pfm_check_task_state(ctx, cmd, flags);
if (unlikely(ret)) goto abort_locked;
skip_fd:
ret = (*func)(ctx, args_k, count, task_pt_regs(current));
call_made = 1;
abort_locked:
if (likely(ctx)) {
DPRINT(("context unlocked\n"));
UNPROTECT_CTX(ctx, flags);
}
/* copy argument back to user, if needed */
if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
error_args:
if (f.file)
fdput(f);
kfree(args_k);
DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));
return ret;
}
static void
pfm_resume_after_ovfl(pfm_context_t *ctx, unsigned long ovfl_regs, struct pt_regs *regs)
{
pfm_buffer_fmt_t *fmt = ctx->ctx_buf_fmt;
pfm_ovfl_ctrl_t rst_ctrl;
int state;
int ret = 0;
state = ctx->ctx_state;
/*
* Unlock sampling buffer and reset index atomically
* XXX: not really needed when blocking
*/
if (CTX_HAS_SMPL(ctx)) {
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 0;
if (state == PFM_CTX_LOADED)
ret = pfm_buf_fmt_restart_active(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
else
ret = pfm_buf_fmt_restart(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
} else {
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 1;
}
if (ret == 0) {
if (rst_ctrl.bits.reset_ovfl_pmds) {
pfm_reset_regs(ctx, &ovfl_regs, PFM_PMD_LONG_RESET);
}
if (rst_ctrl.bits.mask_monitoring == 0) {
DPRINT(("resuming monitoring\n"));
if (ctx->ctx_state == PFM_CTX_MASKED) pfm_restore_monitoring(current);
} else {
DPRINT(("stopping monitoring\n"));
//pfm_stop_monitoring(current, regs);
}
ctx->ctx_state = PFM_CTX_LOADED;
}
}
/*
* context MUST BE LOCKED when calling
* can only be called for current
*/
static void
pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
{
int ret;
DPRINT(("entering for [%d]\n", task_pid_nr(current)));
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
printk(KERN_ERR "pfm_context_force_terminate: [%d] unloaded failed with %d\n", task_pid_nr(current), ret);
}
/*
* and wakeup controlling task, indicating we are now disconnected
*/
wake_up_interruptible(&ctx->ctx_zombieq);
/*
* given that context is still locked, the controlling
* task will only get access when we return from
* pfm_handle_work().
*/
}
static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
/*
* pfm_handle_work() can be called with interrupts enabled
* (TIF_NEED_RESCHED) or disabled. The down_interruptible
* call may sleep, therefore we must re-enable interrupts
* to avoid deadlocks. It is safe to do so because this function
* is called ONLY when returning to user level (pUStk=1), in which case
* there is no risk of kernel stack overflow due to deep
* interrupt nesting.
*/
void
pfm_handle_work(void)
{
pfm_context_t *ctx;
struct pt_regs *regs;
unsigned long flags, dummy_flags;
unsigned long ovfl_regs;
unsigned int reason;
int ret;
ctx = PFM_GET_CTX(current);
if (ctx == NULL) {
printk(KERN_ERR "perfmon: [%d] has no PFM context\n",
task_pid_nr(current));
return;
}
PROTECT_CTX(ctx, flags);
PFM_SET_WORK_PENDING(current, 0);
regs = task_pt_regs(current);
/*
* extract reason for being here and clear
*/
reason = ctx->ctx_fl_trap_reason;
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
ovfl_regs = ctx->ctx_ovfl_regs[0];
DPRINT(("reason=%d state=%d\n", reason, ctx->ctx_state));
/*
* must be done before we check for simple-reset mode
*/
if (ctx->ctx_fl_going_zombie || ctx->ctx_state == PFM_CTX_ZOMBIE)
goto do_zombie;
//if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
if (reason == PFM_TRAP_REASON_RESET)
goto skip_blocking;
/*
* restore interrupt mask to what it was on entry.
* Could be enabled/diasbled.
*/
UNPROTECT_CTX(ctx, flags);
/*
* force interrupt enable because of down_interruptible()
*/
local_irq_enable();
DPRINT(("before block sleeping\n"));
/*
* may go through without blocking on SMP systems
* if restart has been received already by the time we call down()
*/
ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
DPRINT(("after block sleeping ret=%d\n", ret));
/*
* lock context and mask interrupts again
* We save flags into a dummy because we may have
* altered interrupts mask compared to entry in this
* function.
*/
PROTECT_CTX(ctx, dummy_flags);
/*
* we need to read the ovfl_regs only after wake-up
* because we may have had pfm_write_pmds() in between
* and that can changed PMD values and therefore
* ovfl_regs is reset for these new PMD values.
*/
ovfl_regs = ctx->ctx_ovfl_regs[0];
if (ctx->ctx_fl_going_zombie) {
do_zombie:
DPRINT(("context is zombie, bailing out\n"));
pfm_context_force_terminate(ctx, regs);
goto nothing_to_do;
}
/*
* in case of interruption of down() we don't restart anything
*/
if (ret < 0)
goto nothing_to_do;
skip_blocking:
pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
ctx->ctx_ovfl_regs[0] = 0UL;
nothing_to_do:
/*
* restore flags as they were upon entry
*/
UNPROTECT_CTX(ctx, flags);
}
static int
pfm_notify_user(pfm_context_t *ctx, pfm_msg_t *msg)
{
if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
DPRINT(("ignoring overflow notification, owner is zombie\n"));
return 0;
}
DPRINT(("waking up somebody\n"));
if (msg) wake_up_interruptible(&ctx->ctx_msgq_wait);
/*
* safe, we are not in intr handler, nor in ctxsw when
* we come here
*/
kill_fasync (&ctx->ctx_async_queue, SIGIO, POLL_IN);
return 0;
}
static int
pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds)
{
pfm_msg_t *msg = NULL;
if (ctx->ctx_fl_no_msg == 0) {
msg = pfm_get_new_msg(ctx);
if (msg == NULL) {
printk(KERN_ERR "perfmon: pfm_ovfl_notify_user no more notification msgs\n");
return -1;
}
msg->pfm_ovfl_msg.msg_type = PFM_MSG_OVFL;
msg->pfm_ovfl_msg.msg_ctx_fd = ctx->ctx_fd;
msg->pfm_ovfl_msg.msg_active_set = 0;
msg->pfm_ovfl_msg.msg_ovfl_pmds[0] = ovfl_pmds;
msg->pfm_ovfl_msg.msg_ovfl_pmds[1] = 0UL;
msg->pfm_ovfl_msg.msg_ovfl_pmds[2] = 0UL;
msg->pfm_ovfl_msg.msg_ovfl_pmds[3] = 0UL;
msg->pfm_ovfl_msg.msg_tstamp = 0UL;
}
DPRINT(("ovfl msg: msg=%p no_msg=%d fd=%d ovfl_pmds=0x%lx\n",
msg,
ctx->ctx_fl_no_msg,
ctx->ctx_fd,
ovfl_pmds));
return pfm_notify_user(ctx, msg);
}
static int
pfm_end_notify_user(pfm_context_t *ctx)
{
pfm_msg_t *msg;
msg = pfm_get_new_msg(ctx);
if (msg == NULL) {
printk(KERN_ERR "perfmon: pfm_end_notify_user no more notification msgs\n");
return -1;
}
/* no leak */
memset(msg, 0, sizeof(*msg));
msg->pfm_end_msg.msg_type = PFM_MSG_END;
msg->pfm_end_msg.msg_ctx_fd = ctx->ctx_fd;
msg->pfm_ovfl_msg.msg_tstamp = 0UL;
DPRINT(("end msg: msg=%p no_msg=%d ctx_fd=%d\n",
msg,
ctx->ctx_fl_no_msg,
ctx->ctx_fd));
return pfm_notify_user(ctx, msg);
}
/*
* main overflow processing routine.
* it can be called from the interrupt path or explicitly during the context switch code
*/
static void pfm_overflow_handler(struct task_struct *task, pfm_context_t *ctx,
unsigned long pmc0, struct pt_regs *regs)
{
pfm_ovfl_arg_t *ovfl_arg;
unsigned long mask;
unsigned long old_val, ovfl_val, new_val;
unsigned long ovfl_notify = 0UL, ovfl_pmds = 0UL, smpl_pmds = 0UL, reset_pmds;
unsigned long tstamp;
pfm_ovfl_ctrl_t ovfl_ctrl;
unsigned int i, has_smpl;
int must_notify = 0;
if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) goto stop_monitoring;
/*
* sanity test. Should never happen
*/
if (unlikely((pmc0 & 0x1) == 0)) goto sanity_check;
tstamp = ia64_get_itc();
mask = pmc0 >> PMU_FIRST_COUNTER;
ovfl_val = pmu_conf->ovfl_val;
has_smpl = CTX_HAS_SMPL(ctx);
DPRINT_ovfl(("pmc0=0x%lx pid=%d iip=0x%lx, %s "
"used_pmds=0x%lx\n",
pmc0,
task ? task_pid_nr(task): -1,
(regs ? regs->cr_iip : 0),
CTX_OVFL_NOBLOCK(ctx) ? "nonblocking" : "blocking",
ctx->ctx_used_pmds[0]));
/*
* first we update the virtual counters
* assume there was a prior ia64_srlz_d() issued
*/
for (i = PMU_FIRST_COUNTER; mask ; i++, mask >>= 1) {
/* skip pmd which did not overflow */
if ((mask & 0x1) == 0) continue;
/*
* Note that the pmd is not necessarily 0 at this point as qualified events
* may have happened before the PMU was frozen. The residual count is not
* taken into consideration here but will be with any read of the pmd via
* pfm_read_pmds().
*/
old_val = new_val = ctx->ctx_pmds[i].val;
new_val += 1 + ovfl_val;
ctx->ctx_pmds[i].val = new_val;
/*
* check for overflow condition
*/
if (likely(old_val > new_val)) {
ovfl_pmds |= 1UL << i;
if (PMC_OVFL_NOTIFY(ctx, i)) ovfl_notify |= 1UL << i;
}
DPRINT_ovfl(("ctx_pmd[%d].val=0x%lx old_val=0x%lx pmd=0x%lx ovfl_pmds=0x%lx ovfl_notify=0x%lx\n",
i,
new_val,
old_val,
ia64_get_pmd(i) & ovfl_val,
ovfl_pmds,
ovfl_notify));
}
/*
* there was no 64-bit overflow, nothing else to do
*/
if (ovfl_pmds == 0UL) return;
/*
* reset all control bits
*/
ovfl_ctrl.val = 0;
reset_pmds = 0UL;
/*
* if a sampling format module exists, then we "cache" the overflow by
* calling the module's handler() routine.
*/
if (has_smpl) {
unsigned long start_cycles, end_cycles;
unsigned long pmd_mask;
int j, k, ret = 0;
int this_cpu = smp_processor_id();
pmd_mask = ovfl_pmds >> PMU_FIRST_COUNTER;
ovfl_arg = &ctx->ctx_ovfl_arg;
prefetch(ctx->ctx_smpl_hdr);
for(i=PMU_FIRST_COUNTER; pmd_mask && ret == 0; i++, pmd_mask >>=1) {
mask = 1UL << i;
if ((pmd_mask & 0x1) == 0) continue;
ovfl_arg->ovfl_pmd = (unsigned char )i;
ovfl_arg->ovfl_notify = ovfl_notify & mask ? 1 : 0;
ovfl_arg->active_set = 0;
ovfl_arg->ovfl_ctrl.val = 0; /* module must fill in all fields */
ovfl_arg->smpl_pmds[0] = smpl_pmds = ctx->ctx_pmds[i].smpl_pmds[0];
ovfl_arg->pmd_value = ctx->ctx_pmds[i].val;
ovfl_arg->pmd_last_reset = ctx->ctx_pmds[i].lval;
ovfl_arg->pmd_eventid = ctx->ctx_pmds[i].eventid;
/*
* copy values of pmds of interest. Sampling format may copy them
* into sampling buffer.
*/
if (smpl_pmds) {
for(j=0, k=0; smpl_pmds; j++, smpl_pmds >>=1) {
if ((smpl_pmds & 0x1) == 0) continue;
ovfl_arg->smpl_pmds_values[k++] = PMD_IS_COUNTING(j) ? pfm_read_soft_counter(ctx, j) : ia64_get_pmd(j);
DPRINT_ovfl(("smpl_pmd[%d]=pmd%u=0x%lx\n", k-1, j, ovfl_arg->smpl_pmds_values[k-1]));
}
}
pfm_stats[this_cpu].pfm_smpl_handler_calls++;
start_cycles = ia64_get_itc();
/*
* call custom buffer format record (handler) routine
*/
ret = (*ctx->ctx_buf_fmt->fmt_handler)(task, ctx->ctx_smpl_hdr, ovfl_arg, regs, tstamp);
end_cycles = ia64_get_itc();
/*
* For those controls, we take the union because they have
* an all or nothing behavior.
*/
ovfl_ctrl.bits.notify_user |= ovfl_arg->ovfl_ctrl.bits.notify_user;
ovfl_ctrl.bits.block_task |= ovfl_arg->ovfl_ctrl.bits.block_task;
ovfl_ctrl.bits.mask_monitoring |= ovfl_arg->ovfl_ctrl.bits.mask_monitoring;
/*
* build the bitmask of pmds to reset now
*/
if (ovfl_arg->ovfl_ctrl.bits.reset_ovfl_pmds) reset_pmds |= mask;
pfm_stats[this_cpu].pfm_smpl_handler_cycles += end_cycles - start_cycles;
}
/*
* when the module cannot handle the rest of the overflows, we abort right here
*/
if (ret && pmd_mask) {
DPRINT(("handler aborts leftover ovfl_pmds=0x%lx\n",
pmd_mask<<PMU_FIRST_COUNTER));
}
/*
* remove the pmds we reset now from the set of pmds to reset in pfm_restart()
*/
ovfl_pmds &= ~reset_pmds;
} else {
/*
* when no sampling module is used, then the default
* is to notify on overflow if requested by user
*/
ovfl_ctrl.bits.notify_user = ovfl_notify ? 1 : 0;
ovfl_ctrl.bits.block_task = ovfl_notify ? 1 : 0;
ovfl_ctrl.bits.mask_monitoring = ovfl_notify ? 1 : 0; /* XXX: change for saturation */
ovfl_ctrl.bits.reset_ovfl_pmds = ovfl_notify ? 0 : 1;
/*
* if needed, we reset all overflowed pmds
*/
if (ovfl_notify == 0) reset_pmds = ovfl_pmds;
}
DPRINT_ovfl(("ovfl_pmds=0x%lx reset_pmds=0x%lx\n", ovfl_pmds, reset_pmds));
/*
* reset the requested PMD registers using the short reset values
*/
if (reset_pmds) {
unsigned long bm = reset_pmds;
pfm_reset_regs(ctx, &bm, PFM_PMD_SHORT_RESET);
}
if (ovfl_notify && ovfl_ctrl.bits.notify_user) {
/*
* keep track of what to reset when unblocking
*/
ctx->ctx_ovfl_regs[0] = ovfl_pmds;
/*
* check for blocking context
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && ovfl_ctrl.bits.block_task) {
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_BLOCK;
/*
* set the perfmon specific checking pending work for the task
*/
PFM_SET_WORK_PENDING(task, 1);
/*
* when coming from ctxsw, current still points to the
* previous task, therefore we must work with task and not current.
*/
set_notify_resume(task);
}
/*
* defer until state is changed (shorten spin window). the context is locked
* anyway, so the signal receiver would come spin for nothing.
*/
must_notify = 1;
}
DPRINT_ovfl(("owner [%d] pending=%ld reason=%u ovfl_pmds=0x%lx ovfl_notify=0x%lx masked=%d\n",
GET_PMU_OWNER() ? task_pid_nr(GET_PMU_OWNER()) : -1,
PFM_GET_WORK_PENDING(task),
ctx->ctx_fl_trap_reason,
ovfl_pmds,
ovfl_notify,
ovfl_ctrl.bits.mask_monitoring ? 1 : 0));
/*
* in case monitoring must be stopped, we toggle the psr bits
*/
if (ovfl_ctrl.bits.mask_monitoring) {
pfm_mask_monitoring(task);
ctx->ctx_state = PFM_CTX_MASKED;
ctx->ctx_fl_can_restart = 1;
}
/*
* send notification now
*/
if (must_notify) pfm_ovfl_notify_user(ctx, ovfl_notify);
return;
sanity_check:
printk(KERN_ERR "perfmon: CPU%d overflow handler [%d] pmc0=0x%lx\n",
smp_processor_id(),
task ? task_pid_nr(task) : -1,
pmc0);
return;
stop_monitoring:
/*
* in SMP, zombie context is never restored but reclaimed in pfm_load_regs().
* Moreover, zombies are also reclaimed in pfm_save_regs(). Therefore we can
* come here as zombie only if the task is the current task. In which case, we
* can access the PMU hardware directly.
*
* Note that zombies do have PM_VALID set. So here we do the minimal.
*
* In case the context was zombified it could not be reclaimed at the time
* the monitoring program exited. At this point, the PMU reservation has been
* returned, the sampiing buffer has been freed. We must convert this call
* into a spurious interrupt. However, we must also avoid infinite overflows
* by stopping monitoring for this task. We can only come here for a per-task
* context. All we need to do is to stop monitoring using the psr bits which
* are always task private. By re-enabling secure montioring, we ensure that
* the monitored task will not be able to re-activate monitoring.
* The task will eventually be context switched out, at which point the context
* will be reclaimed (that includes releasing ownership of the PMU).
*
* So there might be a window of time where the number of per-task session is zero
* yet one PMU might have a owner and get at most one overflow interrupt for a zombie
* context. This is safe because if a per-task session comes in, it will push this one
* out and by the virtue on pfm_save_regs(), this one will disappear. If a system wide
* session is force on that CPU, given that we use task pinning, pfm_save_regs() will
* also push our zombie context out.
*
* Overall pretty hairy stuff....
*/
DPRINT(("ctx is zombie for [%d], converted to spurious\n", task ? task_pid_nr(task): -1));
pfm_clear_psr_up();
ia64_psr(regs)->up = 0;
ia64_psr(regs)->sp = 1;
return;
}
static int
pfm_do_interrupt_handler(void *arg, struct pt_regs *regs)
{
struct task_struct *task;
pfm_context_t *ctx;
unsigned long flags;
u64 pmc0;
int this_cpu = smp_processor_id();
int retval = 0;
pfm_stats[this_cpu].pfm_ovfl_intr_count++;
/*
* srlz.d done before arriving here
*/
pmc0 = ia64_get_pmc(0);
task = GET_PMU_OWNER();
ctx = GET_PMU_CTX();
/*
* if we have some pending bits set
* assumes : if any PMC0.bit[63-1] is set, then PMC0.fr = 1
*/
if (PMC0_HAS_OVFL(pmc0) && task) {
/*
* we assume that pmc0.fr is always set here
*/
/* sanity check */
if (!ctx) goto report_spurious1;
if (ctx->ctx_fl_system == 0 && (task->thread.flags & IA64_THREAD_PM_VALID) == 0)
goto report_spurious2;
PROTECT_CTX_NOPRINT(ctx, flags);
pfm_overflow_handler(task, ctx, pmc0, regs);
UNPROTECT_CTX_NOPRINT(ctx, flags);
} else {
pfm_stats[this_cpu].pfm_spurious_ovfl_intr_count++;
retval = -1;
}
/*
* keep it unfrozen at all times
*/
pfm_unfreeze_pmu();
return retval;
report_spurious1:
printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d has no PFM context\n",
this_cpu, task_pid_nr(task));
pfm_unfreeze_pmu();
return -1;
report_spurious2:
printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d, invalid flag\n",
this_cpu,
task_pid_nr(task));
pfm_unfreeze_pmu();
return -1;
}
static irqreturn_t
pfm_interrupt_handler(int irq, void *arg)
{
unsigned long start_cycles, total_cycles;
unsigned long min, max;
int this_cpu;
int ret;
struct pt_regs *regs = get_irq_regs();
this_cpu = get_cpu();
if (likely(!pfm_alt_intr_handler)) {
min = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min;
max = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max;
start_cycles = ia64_get_itc();
ret = pfm_do_interrupt_handler(arg, regs);
total_cycles = ia64_get_itc();
/*
* don't measure spurious interrupts
*/
if (likely(ret == 0)) {
total_cycles -= start_cycles;
if (total_cycles < min) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min = total_cycles;
if (total_cycles > max) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max = total_cycles;
pfm_stats[this_cpu].pfm_ovfl_intr_cycles += total_cycles;
}
}
else {
(*pfm_alt_intr_handler->handler)(irq, arg, regs);
}
put_cpu();
return IRQ_HANDLED;
}
/*
* /proc/perfmon interface, for debug only
*/
#define PFM_PROC_SHOW_HEADER ((void *)(long)nr_cpu_ids+1)
static void *
pfm_proc_start(struct seq_file *m, loff_t *pos)
{
if (*pos == 0) {
return PFM_PROC_SHOW_HEADER;
}
while (*pos <= nr_cpu_ids) {
if (cpu_online(*pos - 1)) {
return (void *)*pos;
}
++*pos;
}
return NULL;
}
static void *
pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return pfm_proc_start(m, pos);
}
static void
pfm_proc_stop(struct seq_file *m, void *v)
{
}
static void
pfm_proc_show_header(struct seq_file *m)
{
struct list_head * pos;
pfm_buffer_fmt_t * entry;
unsigned long flags;
seq_printf(m,
"perfmon version : %u.%u\n"
"model : %s\n"
"fastctxsw : %s\n"
"expert mode : %s\n"
"ovfl_mask : 0x%lx\n"
"PMU flags : 0x%x\n",
PFM_VERSION_MAJ, PFM_VERSION_MIN,
pmu_conf->pmu_name,
pfm_sysctl.fastctxsw > 0 ? "Yes": "No",
pfm_sysctl.expert_mode > 0 ? "Yes": "No",
pmu_conf->ovfl_val,
pmu_conf->flags);
LOCK_PFS(flags);
seq_printf(m,
"proc_sessions : %u\n"
"sys_sessions : %u\n"
"sys_use_dbregs : %u\n"
"ptrace_use_dbregs : %u\n",
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_sys_use_dbregs,
pfm_sessions.pfs_ptrace_use_dbregs);
UNLOCK_PFS(flags);
spin_lock(&pfm_buffer_fmt_lock);
list_for_each(pos, &pfm_buffer_fmt_list) {
entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
seq_printf(m, "format : %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x %s\n",
entry->fmt_uuid[0],
entry->fmt_uuid[1],
entry->fmt_uuid[2],
entry->fmt_uuid[3],
entry->fmt_uuid[4],
entry->fmt_uuid[5],
entry->fmt_uuid[6],
entry->fmt_uuid[7],
entry->fmt_uuid[8],
entry->fmt_uuid[9],
entry->fmt_uuid[10],
entry->fmt_uuid[11],
entry->fmt_uuid[12],
entry->fmt_uuid[13],
entry->fmt_uuid[14],
entry->fmt_uuid[15],
entry->fmt_name);
}
spin_unlock(&pfm_buffer_fmt_lock);
}
static int
pfm_proc_show(struct seq_file *m, void *v)
{
unsigned long psr;
unsigned int i;
int cpu;
if (v == PFM_PROC_SHOW_HEADER) {
pfm_proc_show_header(m);
return 0;
}
/* show info for CPU (v - 1) */
cpu = (long)v - 1;
seq_printf(m,
"CPU%-2d overflow intrs : %lu\n"
"CPU%-2d overflow cycles : %lu\n"
"CPU%-2d overflow min : %lu\n"
"CPU%-2d overflow max : %lu\n"
"CPU%-2d smpl handler calls : %lu\n"
"CPU%-2d smpl handler cycles : %lu\n"
"CPU%-2d spurious intrs : %lu\n"
"CPU%-2d replay intrs : %lu\n"
"CPU%-2d syst_wide : %d\n"
"CPU%-2d dcr_pp : %d\n"
"CPU%-2d exclude idle : %d\n"
"CPU%-2d owner : %d\n"
"CPU%-2d context : %p\n"
"CPU%-2d activations : %lu\n",
cpu, pfm_stats[cpu].pfm_ovfl_intr_count,
cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles,
cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_min,
cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_max,
cpu, pfm_stats[cpu].pfm_smpl_handler_calls,
cpu, pfm_stats[cpu].pfm_smpl_handler_cycles,
cpu, pfm_stats[cpu].pfm_spurious_ovfl_intr_count,
cpu, pfm_stats[cpu].pfm_replay_ovfl_intr_count,
cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_SYST_WIDE ? 1 : 0,
cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_DCR_PP ? 1 : 0,
cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_EXCL_IDLE ? 1 : 0,
cpu, pfm_get_cpu_data(pmu_owner, cpu) ? pfm_get_cpu_data(pmu_owner, cpu)->pid: -1,
cpu, pfm_get_cpu_data(pmu_ctx, cpu),
cpu, pfm_get_cpu_data(pmu_activation_number, cpu));
if (num_online_cpus() == 1 && pfm_sysctl.debug > 0) {
psr = pfm_get_psr();
ia64_srlz_d();
seq_printf(m,
"CPU%-2d psr : 0x%lx\n"
"CPU%-2d pmc0 : 0x%lx\n",
cpu, psr,
cpu, ia64_get_pmc(0));
for (i=0; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_COUNTING(i) == 0) continue;
seq_printf(m,
"CPU%-2d pmc%u : 0x%lx\n"
"CPU%-2d pmd%u : 0x%lx\n",
cpu, i, ia64_get_pmc(i),
cpu, i, ia64_get_pmd(i));
}
}
return 0;
}
const struct seq_operations pfm_seq_ops = {
.start = pfm_proc_start,
.next = pfm_proc_next,
.stop = pfm_proc_stop,
.show = pfm_proc_show
};
static int
pfm_proc_open(struct inode *inode, struct file *file)
{
return seq_open(file, &pfm_seq_ops);
}
/*
* we come here as soon as local_cpu_data->pfm_syst_wide is set. this happens
* during pfm_enable() hence before pfm_start(). We cannot assume monitoring
* is active or inactive based on mode. We must rely on the value in
* local_cpu_data->pfm_syst_info
*/
void
pfm_syst_wide_update_task(struct task_struct *task, unsigned long info, int is_ctxswin)
{
struct pt_regs *regs;
unsigned long dcr;
unsigned long dcr_pp;
dcr_pp = info & PFM_CPUINFO_DCR_PP ? 1 : 0;
/*
* pid 0 is guaranteed to be the idle task. There is one such task with pid 0
* on every CPU, so we can rely on the pid to identify the idle task.
*/
if ((info & PFM_CPUINFO_EXCL_IDLE) == 0 || task->pid) {
regs = task_pt_regs(task);
ia64_psr(regs)->pp = is_ctxswin ? dcr_pp : 0;
return;
}
/*
* if monitoring has started
*/
if (dcr_pp) {
dcr = ia64_getreg(_IA64_REG_CR_DCR);
/*
* context switching in?
*/
if (is_ctxswin) {
/* mask monitoring for the idle task */
ia64_setreg(_IA64_REG_CR_DCR, dcr & ~IA64_DCR_PP);
pfm_clear_psr_pp();
ia64_srlz_i();
return;
}
/*
* context switching out
* restore monitoring for next task
*
* Due to inlining this odd if-then-else construction generates
* better code.
*/
ia64_setreg(_IA64_REG_CR_DCR, dcr |IA64_DCR_PP);
pfm_set_psr_pp();
ia64_srlz_i();
}
}
#ifdef CONFIG_SMP
static void
pfm_force_cleanup(pfm_context_t *ctx, struct pt_regs *regs)
{
struct task_struct *task = ctx->ctx_task;
ia64_psr(regs)->up = 0;
ia64_psr(regs)->sp = 1;
if (GET_PMU_OWNER() == task) {
DPRINT(("cleared ownership for [%d]\n",
task_pid_nr(ctx->ctx_task)));
SET_PMU_OWNER(NULL, NULL);
}
/*
* disconnect the task from the context and vice-versa
*/
PFM_SET_WORK_PENDING(task, 0);
task->thread.pfm_context = NULL;
task->thread.flags &= ~IA64_THREAD_PM_VALID;
DPRINT(("force cleanup for [%d]\n", task_pid_nr(task)));
}
/*
* in 2.6, interrupts are masked when we come here and the runqueue lock is held
*/
void
pfm_save_regs(struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long flags;
u64 psr;
ctx = PFM_GET_CTX(task);
if (ctx == NULL) return;
/*
* we always come here with interrupts ALREADY disabled by
* the scheduler. So we simply need to protect against concurrent
* access, not CPU concurrency.
*/
flags = pfm_protect_ctx_ctxsw(ctx);
if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
struct pt_regs *regs = task_pt_regs(task);
pfm_clear_psr_up();
pfm_force_cleanup(ctx, regs);
BUG_ON(ctx->ctx_smpl_hdr);
pfm_unprotect_ctx_ctxsw(ctx, flags);
pfm_context_free(ctx);
return;
}
/*
* save current PSR: needed because we modify it
*/
ia64_srlz_d();
psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_I));
/*
* stop monitoring:
* This is the last instruction which may generate an overflow
*
* We do not need to set psr.sp because, it is irrelevant in kernel.
* It will be restored from ipsr when going back to user level
*/
pfm_clear_psr_up();
/*
* keep a copy of psr.up (for reload)
*/
ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
/*
* release ownership of this PMU.
* PM interrupts are masked, so nothing
* can happen.
*/
SET_PMU_OWNER(NULL, NULL);
/*
* we systematically save the PMD as we have no
* guarantee we will be schedule at that same
* CPU again.
*/
pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
/*
* save pmc0 ia64_srlz_d() done in pfm_save_pmds()
* we will need it on the restore path to check
* for pending overflow.
*/
ctx->th_pmcs[0] = ia64_get_pmc(0);
/*
* unfreeze PMU if had pending overflows
*/
if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
/*
* finally, allow context access.
* interrupts will still be masked after this call.
*/
pfm_unprotect_ctx_ctxsw(ctx, flags);
}
#else /* !CONFIG_SMP */
void
pfm_save_regs(struct task_struct *task)
{
pfm_context_t *ctx;
u64 psr;
ctx = PFM_GET_CTX(task);
if (ctx == NULL) return;
/*
* save current PSR: needed because we modify it
*/
psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_I));
/*
* stop monitoring:
* This is the last instruction which may generate an overflow
*
* We do not need to set psr.sp because, it is irrelevant in kernel.
* It will be restored from ipsr when going back to user level
*/
pfm_clear_psr_up();
/*
* keep a copy of psr.up (for reload)
*/
ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
}
static void
pfm_lazy_save_regs (struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long flags;
{ u64 psr = pfm_get_psr();
BUG_ON(psr & IA64_PSR_UP);
}
ctx = PFM_GET_CTX(task);
/*
* we need to mask PMU overflow here to
* make sure that we maintain pmc0 until
* we save it. overflow interrupts are
* treated as spurious if there is no
* owner.
*
* XXX: I don't think this is necessary
*/
PROTECT_CTX(ctx,flags);
/*
* release ownership of this PMU.
* must be done before we save the registers.
*
* after this call any PMU interrupt is treated
* as spurious.
*/
SET_PMU_OWNER(NULL, NULL);
/*
* save all the pmds we use
*/
pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
/*
* save pmc0 ia64_srlz_d() done in pfm_save_pmds()
* it is needed to check for pended overflow
* on the restore path
*/
ctx->th_pmcs[0] = ia64_get_pmc(0);
/*
* unfreeze PMU if had pending overflows
*/
if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
/*
* now get can unmask PMU interrupts, they will
* be treated as purely spurious and we will not
* lose any information
*/
UNPROTECT_CTX(ctx,flags);
}
#endif /* CONFIG_SMP */
#ifdef CONFIG_SMP
/*
* in 2.6, interrupts are masked when we come here and the runqueue lock is held
*/
void
pfm_load_regs (struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long pmc_mask = 0UL, pmd_mask = 0UL;
unsigned long flags;
u64 psr, psr_up;
int need_irq_resend;
ctx = PFM_GET_CTX(task);
if (unlikely(ctx == NULL)) return;
BUG_ON(GET_PMU_OWNER());
/*
* possible on unload
*/
if (unlikely((task->thread.flags & IA64_THREAD_PM_VALID) == 0)) return;
/*
* we always come here with interrupts ALREADY disabled by
* the scheduler. So we simply need to protect against concurrent
* access, not CPU concurrency.
*/
flags = pfm_protect_ctx_ctxsw(ctx);
psr = pfm_get_psr();
need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
BUG_ON(psr & IA64_PSR_I);
if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) {
struct pt_regs *regs = task_pt_regs(task);
BUG_ON(ctx->ctx_smpl_hdr);
pfm_force_cleanup(ctx, regs);
pfm_unprotect_ctx_ctxsw(ctx, flags);
/*
* this one (kmalloc'ed) is fine with interrupts disabled
*/
pfm_context_free(ctx);
return;
}
/*
* we restore ALL the debug registers to avoid picking up
* stale state.
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* retrieve saved psr.up
*/
psr_up = ctx->ctx_saved_psr_up;
/*
* if we were the last user of the PMU on that CPU,
* then nothing to do except restore psr
*/
if (GET_LAST_CPU(ctx) == smp_processor_id() && ctx->ctx_last_activation == GET_ACTIVATION()) {
/*
* retrieve partial reload masks (due to user modifications)
*/
pmc_mask = ctx->ctx_reload_pmcs[0];
pmd_mask = ctx->ctx_reload_pmds[0];
} else {
/*
* To avoid leaking information to the user level when psr.sp=0,
* we must reload ALL implemented pmds (even the ones we don't use).
* In the kernel we only allow PFM_READ_PMDS on registers which
* we initialized or requested (sampling) so there is no risk there.
*/
pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
/*
* ALL accessible PMCs are systematically reloaded, unused registers
* get their default (from pfm_reset_pmu_state()) values to avoid picking
* up stale configuration.
*
* PMC0 is never in the mask. It is always restored separately.
*/
pmc_mask = ctx->ctx_all_pmcs[0];
}
/*
* when context is MASKED, we will restore PMC with plm=0
* and PMD with stale information, but that's ok, nothing
* will be captured.
*
* XXX: optimize here
*/
if (pmd_mask) pfm_restore_pmds(ctx->th_pmds, pmd_mask);
if (pmc_mask) pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
/*
* check for pending overflow at the time the state
* was saved.
*/
if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
/*
* reload pmc0 with the overflow information
* On McKinley PMU, this will trigger a PMU interrupt
*/
ia64_set_pmc(0, ctx->th_pmcs[0]);
ia64_srlz_d();
ctx->th_pmcs[0] = 0UL;
/*
* will replay the PMU interrupt
*/
if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
}
/*
* we just did a reload, so we reset the partial reload fields
*/
ctx->ctx_reload_pmcs[0] = 0UL;
ctx->ctx_reload_pmds[0] = 0UL;
SET_LAST_CPU(ctx, smp_processor_id());
/*
* dump activation value for this PMU
*/
INC_ACTIVATION();
/*
* record current activation for this context
*/
SET_ACTIVATION(ctx);
/*
* establish new ownership.
*/
SET_PMU_OWNER(task, ctx);
/*
* restore the psr.up bit. measurement
* is active again.
* no PMU interrupt can happen at this point
* because we still have interrupts disabled.
*/
if (likely(psr_up)) pfm_set_psr_up();
/*
* allow concurrent access to context
*/
pfm_unprotect_ctx_ctxsw(ctx, flags);
}
#else /* !CONFIG_SMP */
/*
* reload PMU state for UP kernels
* in 2.5 we come here with interrupts disabled
*/
void
pfm_load_regs (struct task_struct *task)
{
pfm_context_t *ctx;
struct task_struct *owner;
unsigned long pmd_mask, pmc_mask;
u64 psr, psr_up;
int need_irq_resend;
owner = GET_PMU_OWNER();
ctx = PFM_GET_CTX(task);
psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
BUG_ON(psr & IA64_PSR_I);
/*
* we restore ALL the debug registers to avoid picking up
* stale state.
*
* This must be done even when the task is still the owner
* as the registers may have been modified via ptrace()
* (not perfmon) by the previous task.
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* retrieved saved psr.up
*/
psr_up = ctx->ctx_saved_psr_up;
need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
/*
* short path, our state is still there, just
* need to restore psr and we go
*
* we do not touch either PMC nor PMD. the psr is not touched
* by the overflow_handler. So we are safe w.r.t. to interrupt
* concurrency even without interrupt masking.
*/
if (likely(owner == task)) {
if (likely(psr_up)) pfm_set_psr_up();
return;
}
/*
* someone else is still using the PMU, first push it out and
* then we'll be able to install our stuff !
*
* Upon return, there will be no owner for the current PMU
*/
if (owner) pfm_lazy_save_regs(owner);
/*
* To avoid leaking information to the user level when psr.sp=0,
* we must reload ALL implemented pmds (even the ones we don't use).
* In the kernel we only allow PFM_READ_PMDS on registers which
* we initialized or requested (sampling) so there is no risk there.
*/
pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
/*
* ALL accessible PMCs are systematically reloaded, unused registers
* get their default (from pfm_reset_pmu_state()) values to avoid picking
* up stale configuration.
*
* PMC0 is never in the mask. It is always restored separately
*/
pmc_mask = ctx->ctx_all_pmcs[0];
pfm_restore_pmds(ctx->th_pmds, pmd_mask);
pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
/*
* check for pending overflow at the time the state
* was saved.
*/
if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
/*
* reload pmc0 with the overflow information
* On McKinley PMU, this will trigger a PMU interrupt
*/
ia64_set_pmc(0, ctx->th_pmcs[0]);
ia64_srlz_d();
ctx->th_pmcs[0] = 0UL;
/*
* will replay the PMU interrupt
*/
if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
}
/*
* establish new ownership.
*/
SET_PMU_OWNER(task, ctx);
/*
* restore the psr.up bit. measurement
* is active again.
* no PMU interrupt can happen at this point
* because we still have interrupts disabled.
*/
if (likely(psr_up)) pfm_set_psr_up();
}
#endif /* CONFIG_SMP */
/*
* this function assumes monitoring is stopped
*/
static void
pfm_flush_pmds(struct task_struct *task, pfm_context_t *ctx)
{
u64 pmc0;
unsigned long mask2, val, pmd_val, ovfl_val;
int i, can_access_pmu = 0;
int is_self;
/*
* is the caller the task being monitored (or which initiated the
* session for system wide measurements)
*/
is_self = ctx->ctx_task == task ? 1 : 0;
/*
* can access PMU is task is the owner of the PMU state on the current CPU
* or if we are running on the CPU bound to the context in system-wide mode
* (that is not necessarily the task the context is attached to in this mode).
* In system-wide we always have can_access_pmu true because a task running on an
* invalid processor is flagged earlier in the call stack (see pfm_stop).
*/
can_access_pmu = (GET_PMU_OWNER() == task) || (ctx->ctx_fl_system && ctx->ctx_cpu == smp_processor_id());
if (can_access_pmu) {
/*
* Mark the PMU as not owned
* This will cause the interrupt handler to do nothing in case an overflow
* interrupt was in-flight
* This also guarantees that pmc0 will contain the final state
* It virtually gives us full control on overflow processing from that point
* on.
*/
SET_PMU_OWNER(NULL, NULL);
DPRINT(("releasing ownership\n"));
/*
* read current overflow status:
*
* we are guaranteed to read the final stable state
*/
ia64_srlz_d();
pmc0 = ia64_get_pmc(0); /* slow */
/*
* reset freeze bit, overflow status information destroyed
*/
pfm_unfreeze_pmu();
} else {
pmc0 = ctx->th_pmcs[0];
/*
* clear whatever overflow status bits there were
*/
ctx->th_pmcs[0] = 0;
}
ovfl_val = pmu_conf->ovfl_val;
/*
* we save all the used pmds
* we take care of overflows for counting PMDs
*
* XXX: sampling situation is not taken into account here
*/
mask2 = ctx->ctx_used_pmds[0];
DPRINT(("is_self=%d ovfl_val=0x%lx mask2=0x%lx\n", is_self, ovfl_val, mask2));
for (i = 0; mask2; i++, mask2>>=1) {
/* skip non used pmds */
if ((mask2 & 0x1) == 0) continue;
/*
* can access PMU always true in system wide mode
*/
val = pmd_val = can_access_pmu ? ia64_get_pmd(i) : ctx->th_pmds[i];
if (PMD_IS_COUNTING(i)) {
DPRINT(("[%d] pmd[%d] ctx_pmd=0x%lx hw_pmd=0x%lx\n",
task_pid_nr(task),
i,
ctx->ctx_pmds[i].val,
val & ovfl_val));
/*
* we rebuild the full 64 bit value of the counter
*/
val = ctx->ctx_pmds[i].val + (val & ovfl_val);
/*
* now everything is in ctx_pmds[] and we need
* to clear the saved context from save_regs() such that
* pfm_read_pmds() gets the correct value
*/
pmd_val = 0UL;
/*
* take care of overflow inline
*/
if (pmc0 & (1UL << i)) {
val += 1 + ovfl_val;
DPRINT(("[%d] pmd[%d] overflowed\n", task_pid_nr(task), i));
}
}
DPRINT(("[%d] ctx_pmd[%d]=0x%lx pmd_val=0x%lx\n", task_pid_nr(task), i, val, pmd_val));
if (is_self) ctx->th_pmds[i] = pmd_val;
ctx->ctx_pmds[i].val = val;
}
}
static struct irqaction perfmon_irqaction = {
.handler = pfm_interrupt_handler,
.flags = IRQF_DISABLED,
.name = "perfmon"
};
static void
pfm_alt_save_pmu_state(void *data)
{
struct pt_regs *regs;
regs = task_pt_regs(current);
DPRINT(("called\n"));
/*
* should not be necessary but
* let's take not risk
*/
pfm_clear_psr_up();
pfm_clear_psr_pp();
ia64_psr(regs)->pp = 0;
/*
* This call is required
* May cause a spurious interrupt on some processors
*/
pfm_freeze_pmu();
ia64_srlz_d();
}
void
pfm_alt_restore_pmu_state(void *data)
{
struct pt_regs *regs;
regs = task_pt_regs(current);
DPRINT(("called\n"));
/*
* put PMU back in state expected
* by perfmon
*/
pfm_clear_psr_up();
pfm_clear_psr_pp();
ia64_psr(regs)->pp = 0;
/*
* perfmon runs with PMU unfrozen at all times
*/
pfm_unfreeze_pmu();
ia64_srlz_d();
}
int
pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
{
int ret, i;
int reserve_cpu;
/* some sanity checks */
if (hdl == NULL || hdl->handler == NULL) return -EINVAL;
/* do the easy test first */
if (pfm_alt_intr_handler) return -EBUSY;
/* one at a time in the install or remove, just fail the others */
if (!spin_trylock(&pfm_alt_install_check)) {
return -EBUSY;
}
/* reserve our session */
for_each_online_cpu(reserve_cpu) {
ret = pfm_reserve_session(NULL, 1, reserve_cpu);
if (ret) goto cleanup_reserve;
}
/* save the current system wide pmu states */
ret = on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);
if (ret) {
DPRINT(("on_each_cpu() failed: %d\n", ret));
goto cleanup_reserve;
}
/* officially change to the alternate interrupt handler */
pfm_alt_intr_handler = hdl;
spin_unlock(&pfm_alt_install_check);
return 0;
cleanup_reserve:
for_each_online_cpu(i) {
/* don't unreserve more than we reserved */
if (i >= reserve_cpu) break;
pfm_unreserve_session(NULL, 1, i);
}
spin_unlock(&pfm_alt_install_check);
return ret;
}
EXPORT_SYMBOL_GPL(pfm_install_alt_pmu_interrupt);
int
pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
{
int i;
int ret;
if (hdl == NULL) return -EINVAL;
/* cannot remove someone else's handler! */
if (pfm_alt_intr_handler != hdl) return -EINVAL;
/* one at a time in the install or remove, just fail the others */
if (!spin_trylock(&pfm_alt_install_check)) {
return -EBUSY;
}
pfm_alt_intr_handler = NULL;
ret = on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);
if (ret) {
DPRINT(("on_each_cpu() failed: %d\n", ret));
}
for_each_online_cpu(i) {
pfm_unreserve_session(NULL, 1, i);
}
spin_unlock(&pfm_alt_install_check);
return 0;
}
EXPORT_SYMBOL_GPL(pfm_remove_alt_pmu_interrupt);
/*
* perfmon initialization routine, called from the initcall() table
*/
static int init_pfm_fs(void);
static int __init
pfm_probe_pmu(void)
{
pmu_config_t **p;
int family;
family = local_cpu_data->family;
p = pmu_confs;
while(*p) {
if ((*p)->probe) {
if ((*p)->probe() == 0) goto found;
} else if ((*p)->pmu_family == family || (*p)->pmu_family == 0xff) {
goto found;
}
p++;
}
return -1;
found:
pmu_conf = *p;
return 0;
}
static const struct file_operations pfm_proc_fops = {
.open = pfm_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
int __init
pfm_init(void)
{
unsigned int n, n_counters, i;
printk("perfmon: version %u.%u IRQ %u\n",
PFM_VERSION_MAJ,
PFM_VERSION_MIN,
IA64_PERFMON_VECTOR);
if (pfm_probe_pmu()) {
printk(KERN_INFO "perfmon: disabled, there is no support for processor family %d\n",
local_cpu_data->family);
return -ENODEV;
}
/*
* compute the number of implemented PMD/PMC from the
* description tables
*/
n = 0;
for (i=0; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_IMPL(i) == 0) continue;
pmu_conf->impl_pmcs[i>>6] |= 1UL << (i&63);
n++;
}
pmu_conf->num_pmcs = n;
n = 0; n_counters = 0;
for (i=0; PMD_IS_LAST(i) == 0; i++) {
if (PMD_IS_IMPL(i) == 0) continue;
pmu_conf->impl_pmds[i>>6] |= 1UL << (i&63);
n++;
if (PMD_IS_COUNTING(i)) n_counters++;
}
pmu_conf->num_pmds = n;
pmu_conf->num_counters = n_counters;
/*
* sanity checks on the number of debug registers
*/
if (pmu_conf->use_rr_dbregs) {
if (pmu_conf->num_ibrs > IA64_NUM_DBG_REGS) {
printk(KERN_INFO "perfmon: unsupported number of code debug registers (%u)\n", pmu_conf->num_ibrs);
pmu_conf = NULL;
return -1;
}
if (pmu_conf->num_dbrs > IA64_NUM_DBG_REGS) {
printk(KERN_INFO "perfmon: unsupported number of data debug registers (%u)\n", pmu_conf->num_ibrs);
pmu_conf = NULL;
return -1;
}
}
printk("perfmon: %s PMU detected, %u PMCs, %u PMDs, %u counters (%lu bits)\n",
pmu_conf->pmu_name,
pmu_conf->num_pmcs,
pmu_conf->num_pmds,
pmu_conf->num_counters,
ffz(pmu_conf->ovfl_val));
/* sanity check */
if (pmu_conf->num_pmds >= PFM_NUM_PMD_REGS || pmu_conf->num_pmcs >= PFM_NUM_PMC_REGS) {
printk(KERN_ERR "perfmon: not enough pmc/pmd, perfmon disabled\n");
pmu_conf = NULL;
return -1;
}
/*
* create /proc/perfmon (mostly for debugging purposes)
*/
perfmon_dir = proc_create("perfmon", S_IRUGO, NULL, &pfm_proc_fops);
if (perfmon_dir == NULL) {
printk(KERN_ERR "perfmon: cannot create /proc entry, perfmon disabled\n");
pmu_conf = NULL;
return -1;
}
/*
* create /proc/sys/kernel/perfmon (for debugging purposes)
*/
pfm_sysctl_header = register_sysctl_table(pfm_sysctl_root);
/*
* initialize all our spinlocks
*/
spin_lock_init(&pfm_sessions.pfs_lock);
spin_lock_init(&pfm_buffer_fmt_lock);
init_pfm_fs();
for(i=0; i < NR_CPUS; i++) pfm_stats[i].pfm_ovfl_intr_cycles_min = ~0UL;
return 0;
}
__initcall(pfm_init);
/*
* this function is called before pfm_init()
*/
void
pfm_init_percpu (void)
{
static int first_time=1;
/*
* make sure no measurement is active
* (may inherit programmed PMCs from EFI).
*/
pfm_clear_psr_pp();
pfm_clear_psr_up();
/*
* we run with the PMU not frozen at all times
*/
pfm_unfreeze_pmu();
if (first_time) {
register_percpu_irq(IA64_PERFMON_VECTOR, &perfmon_irqaction);
first_time=0;
}
ia64_setreg(_IA64_REG_CR_PMV, IA64_PERFMON_VECTOR);
ia64_srlz_d();
}
/*
* used for debug purposes only
*/
void
dump_pmu_state(const char *from)
{
struct task_struct *task;
struct pt_regs *regs;
pfm_context_t *ctx;
unsigned long psr, dcr, info, flags;
int i, this_cpu;
local_irq_save(flags);
this_cpu = smp_processor_id();
regs = task_pt_regs(current);
info = PFM_CPUINFO_GET();
dcr = ia64_getreg(_IA64_REG_CR_DCR);
if (info == 0 && ia64_psr(regs)->pp == 0 && (dcr & IA64_DCR_PP) == 0) {
local_irq_restore(flags);
return;
}
printk("CPU%d from %s() current [%d] iip=0x%lx %s\n",
this_cpu,
from,
task_pid_nr(current),
regs->cr_iip,
current->comm);
task = GET_PMU_OWNER();
ctx = GET_PMU_CTX();
printk("->CPU%d owner [%d] ctx=%p\n", this_cpu, task ? task_pid_nr(task) : -1, ctx);
psr = pfm_get_psr();
printk("->CPU%d pmc0=0x%lx psr.pp=%d psr.up=%d dcr.pp=%d syst_info=0x%lx user_psr.up=%d user_psr.pp=%d\n",
this_cpu,
ia64_get_pmc(0),
psr & IA64_PSR_PP ? 1 : 0,
psr & IA64_PSR_UP ? 1 : 0,
dcr & IA64_DCR_PP ? 1 : 0,
info,
ia64_psr(regs)->up,
ia64_psr(regs)->pp);
ia64_psr(regs)->up = 0;
ia64_psr(regs)->pp = 0;
for (i=1; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_IMPL(i) == 0) continue;
printk("->CPU%d pmc[%d]=0x%lx thread_pmc[%d]=0x%lx\n", this_cpu, i, ia64_get_pmc(i), i, ctx->th_pmcs[i]);
}
for (i=1; PMD_IS_LAST(i) == 0; i++) {
if (PMD_IS_IMPL(i) == 0) continue;
printk("->CPU%d pmd[%d]=0x%lx thread_pmd[%d]=0x%lx\n", this_cpu, i, ia64_get_pmd(i), i, ctx->th_pmds[i]);
}
if (ctx) {
printk("->CPU%d ctx_state=%d vaddr=%p addr=%p fd=%d ctx_task=[%d] saved_psr_up=0x%lx\n",
this_cpu,
ctx->ctx_state,
ctx->ctx_smpl_vaddr,
ctx->ctx_smpl_hdr,
ctx->ctx_msgq_head,
ctx->ctx_msgq_tail,
ctx->ctx_saved_psr_up);
}
local_irq_restore(flags);
}
/*
* called from process.c:copy_thread(). task is new child.
*/
void
pfm_inherit(struct task_struct *task, struct pt_regs *regs)
{
struct thread_struct *thread;
DPRINT(("perfmon: pfm_inherit clearing state for [%d]\n", task_pid_nr(task)));
thread = &task->thread;
/*
* cut links inherited from parent (current)
*/
thread->pfm_context = NULL;
PFM_SET_WORK_PENDING(task, 0);
/*
* the psr bits are already set properly in copy_threads()
*/
}
#else /* !CONFIG_PERFMON */
asmlinkage long
sys_perfmonctl (int fd, int cmd, void *arg, int count)
{
return -ENOSYS;
}
#endif /* CONFIG_PERFMON */