/*
* Cell Broadband Engine OProfile Support
*
* (C) Copyright IBM Corporation 2006
*
* Author: David Erb (djerb@us.ibm.com)
* Modifications:
* Carl Love <carll@us.ibm.com>
* Maynard Johnson <maynardj@us.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kthread.h>
#include <linux/oprofile.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <asm/cell-pmu.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/io.h>
#include <asm/oprofile_impl.h>
#include <asm/processor.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/reg.h>
#include <asm/rtas.h>
#include <asm/cell-regs.h>
#include "../platforms/cell/interrupt.h"
#include "cell/pr_util.h"
#define PPU_PROFILING 0
#define SPU_PROFILING_CYCLES 1
#define SPU_PROFILING_EVENTS 2
#define SPU_EVENT_NUM_START 4100
#define SPU_EVENT_NUM_STOP 4399
#define SPU_PROFILE_EVENT_ADDR 4363 /* spu, address trace, decimal */
#define SPU_PROFILE_EVENT_ADDR_MASK_A 0x146 /* sub unit set to zero */
#define SPU_PROFILE_EVENT_ADDR_MASK_B 0x186 /* sub unit set to zero */
#define NUM_SPUS_PER_NODE 8
#define SPU_CYCLES_EVENT_NUM 2 /* event number for SPU_CYCLES */
#define PPU_CYCLES_EVENT_NUM 1 /* event number for CYCLES */
#define PPU_CYCLES_GRP_NUM 1 /* special group number for identifying
* PPU_CYCLES event
*/
#define CBE_COUNT_ALL_CYCLES 0x42800000 /* PPU cycle event specifier */
#define NUM_THREADS 2 /* number of physical threads in
* physical processor
*/
#define NUM_DEBUG_BUS_WORDS 4
#define NUM_INPUT_BUS_WORDS 2
#define MAX_SPU_COUNT 0xFFFFFF /* maximum 24 bit LFSR value */
/* Minimum HW interval timer setting to send value to trace buffer is 10 cycle.
* To configure counter to send value every N cycles set counter to
* 2^32 - 1 - N.
*/
#define NUM_INTERVAL_CYC 0xFFFFFFFF - 10
/*
* spu_cycle_reset is the number of cycles between samples.
* This variable is used for SPU profiling and should ONLY be set
* at the beginning of cell_reg_setup; otherwise, it's read-only.
*/
static unsigned int spu_cycle_reset;
static unsigned int profiling_mode;
static int spu_evnt_phys_spu_indx;
struct pmc_cntrl_data {
unsigned long vcntr;
unsigned long evnts;
unsigned long masks;
unsigned long enabled;
};
/*
* ibm,cbe-perftools rtas parameters
*/
struct pm_signal {
u16 cpu; /* Processor to modify */
u16 sub_unit; /* hw subunit this applies to (if applicable)*/
short int signal_group; /* Signal Group to Enable/Disable */
u8 bus_word; /* Enable/Disable on this Trace/Trigger/Event
* Bus Word(s) (bitmask)
*/
u8 bit; /* Trigger/Event bit (if applicable) */
};
/*
* rtas call arguments
*/
enum {
SUBFUNC_RESET = 1,
SUBFUNC_ACTIVATE = 2,
SUBFUNC_DEACTIVATE = 3,
PASSTHRU_IGNORE = 0,
PASSTHRU_ENABLE = 1,
PASSTHRU_DISABLE = 2,
};
struct pm_cntrl {
u16 enable;
u16 stop_at_max;
u16 trace_mode;
u16 freeze;
u16 count_mode;
u16 spu_addr_trace;
u8 trace_buf_ovflw;
};
static struct {
u32 group_control;
u32 debug_bus_control;
struct pm_cntrl pm_cntrl;
u32 pm07_cntrl[NR_PHYS_CTRS];
} pm_regs;
#define GET_SUB_UNIT(x) ((x & 0x0000f000) >> 12)
#define GET_BUS_WORD(x) ((x & 0x000000f0) >> 4)
#define GET_BUS_TYPE(x) ((x & 0x00000300) >> 8)
#define GET_POLARITY(x) ((x & 0x00000002) >> 1)
#define GET_COUNT_CYCLES(x) (x & 0x00000001)
#define GET_INPUT_CONTROL(x) ((x & 0x00000004) >> 2)
static DEFINE_PER_CPU(unsigned long[NR_PHYS_CTRS], pmc_values);
static unsigned long spu_pm_cnt[MAX_NUMNODES * NUM_SPUS_PER_NODE];
static struct pmc_cntrl_data pmc_cntrl[NUM_THREADS][NR_PHYS_CTRS];
/*
* The CELL profiling code makes rtas calls to setup the debug bus to
* route the performance signals. Additionally, SPU profiling requires
* a second rtas call to setup the hardware to capture the SPU PCs.
* The EIO error value is returned if the token lookups or the rtas
* call fail. The EIO error number is the best choice of the existing
* error numbers. The probability of rtas related error is very low. But
* by returning EIO and printing additional information to dmsg the user
* will know that OProfile did not start and dmesg will tell them why.
* OProfile does not support returning errors on Stop. Not a huge issue
* since failure to reset the debug bus or stop the SPU PC collection is
* not a fatel issue. Chances are if the Stop failed, Start doesn't work
* either.
*/
/*
* Interpetation of hdw_thread:
* 0 - even virtual cpus 0, 2, 4,...
* 1 - odd virtual cpus 1, 3, 5, ...
*
* FIXME: this is strictly wrong, we need to clean this up in a number
* of places. It works for now. -arnd
*/
static u32 hdw_thread;
static u32 virt_cntr_inter_mask;
static struct timer_list timer_virt_cntr;
static struct timer_list timer_spu_event_swap;
/*
* pm_signal needs to be global since it is initialized in
* cell_reg_setup at the time when the necessary information
* is available.
*/
static struct pm_signal pm_signal[NR_PHYS_CTRS];
static int pm_rtas_token; /* token for debug bus setup call */
static int spu_rtas_token; /* token for SPU cycle profiling */
static u32 reset_value[NR_PHYS_CTRS];
static int num_counters;
static int oprofile_running;
static DEFINE_SPINLOCK(cntr_lock);
static u32 ctr_enabled;
static unsigned char input_bus[NUM_INPUT_BUS_WORDS];
/*
* Firmware interface functions
*/
static int
rtas_ibm_cbe_perftools(int subfunc, int passthru,
void *address, unsigned long length)
{
u64 paddr = __pa(address);
return rtas_call(pm_rtas_token, 5, 1, NULL, subfunc,
passthru, paddr >> 32, paddr & 0xffffffff, length);
}
static void pm_rtas_reset_signals(u32 node)
{
int ret;
struct pm_signal pm_signal_local;
/*
* The debug bus is being set to the passthru disable state.
* However, the FW still expects atleast one legal signal routing
* entry or it will return an error on the arguments. If we don't
* supply a valid entry, we must ignore all return values. Ignoring
* all return values means we might miss an error we should be
* concerned about.
*/
/* fw expects physical cpu #. */
pm_signal_local.cpu = node;
pm_signal_local.signal_group = 21;
pm_signal_local.bus_word = 1;
pm_signal_local.sub_unit = 0;
pm_signal_local.bit = 0;
ret = rtas_ibm_cbe_perftools(SUBFUNC_RESET, PASSTHRU_DISABLE,
&pm_signal_local,
sizeof(struct pm_signal));
if (unlikely(ret))
/*
* Not a fatal error. For Oprofile stop, the oprofile
* functions do not support returning an error for
* failure to stop OProfile.
*/
printk(KERN_WARNING "%s: rtas returned: %d\n",
__func__, ret);
}
static int pm_rtas_activate_signals(u32 node, u32 count)
{
int ret;
int i, j;
struct pm_signal pm_signal_local[NR_PHYS_CTRS];
/*
* There is no debug setup required for the cycles event.
* Note that only events in the same group can be used.
* Otherwise, there will be conflicts in correctly routing
* the signals on the debug bus. It is the responsibility
* of the OProfile user tool to check the events are in
* the same group.
*/
i = 0;
for (j = 0; j < count; j++) {
if (pm_signal[j].signal_group != PPU_CYCLES_GRP_NUM) {
/* fw expects physical cpu # */
pm_signal_local[i].cpu = node;
pm_signal_local[i].signal_group
= pm_signal[j].signal_group;
pm_signal_local[i].bus_word = pm_signal[j].bus_word;
pm_signal_local[i].sub_unit = pm_signal[j].sub_unit;
pm_signal_local[i].bit = pm_signal[j].bit;
i++;
}
}
if (i != 0) {
ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE, PASSTHRU_ENABLE,
pm_signal_local,
i * sizeof(struct pm_signal));
if (unlikely(ret)) {
printk(KERN_WARNING "%s: rtas returned: %d\n",
__func__, ret);
return -EIO;
}
}
return 0;
}
/*
* PM Signal functions
*/
static void set_pm_event(u32 ctr, int event, u32 unit_mask)
{
struct pm_signal *p;
u32 signal_bit;
u32 bus_word, bus_type, count_cycles, polarity, input_control;
int j, i;
if (event == PPU_CYCLES_EVENT_NUM) {
/* Special Event: Count all cpu cycles */
pm_regs.pm07_cntrl[ctr] = CBE_COUNT_ALL_CYCLES;
p = &(pm_signal[ctr]);
p->signal_group = PPU_CYCLES_GRP_NUM;
p->bus_word = 1;
p->sub_unit = 0;
p->bit = 0;
goto out;
} else {
pm_regs.pm07_cntrl[ctr] = 0;
}
bus_word = GET_BUS_WORD(unit_mask);
bus_type = GET_BUS_TYPE(unit_mask);
count_cycles = GET_COUNT_CYCLES(unit_mask);
polarity = GET_POLARITY(unit_mask);
input_control = GET_INPUT_CONTROL(unit_mask);
signal_bit = (event % 100);
p = &(pm_signal[ctr]);
p->signal_group = event / 100;
p->bus_word = bus_word;
p->sub_unit = GET_SUB_UNIT(unit_mask);
pm_regs.pm07_cntrl[ctr] = 0;
pm_regs.pm07_cntrl[ctr] |= PM07_CTR_COUNT_CYCLES(count_cycles);
pm_regs.pm07_cntrl[ctr] |= PM07_CTR_POLARITY(polarity);
pm_regs.pm07_cntrl[ctr] |= PM07_CTR_INPUT_CONTROL(input_control);
/*
* Some of the islands signal selection is based on 64 bit words.
* The debug bus words are 32 bits, the input words to the performance
* counters are defined as 32 bits. Need to convert the 64 bit island
* specification to the appropriate 32 input bit and bus word for the
* performance counter event selection. See the CELL Performance
* monitoring signals manual and the Perf cntr hardware descriptions
* for the details.
*/
if (input_control == 0) {
if (signal_bit > 31) {
signal_bit -= 32;
if (bus_word == 0x3)
bus_word = 0x2;
else if (bus_word == 0xc)
bus_word = 0x8;
}
if ((bus_type == 0) && p->signal_group >= 60)
bus_type = 2;
if ((bus_type == 1) && p->signal_group >= 50)
bus_type = 0;
pm_regs.pm07_cntrl[ctr] |= PM07_CTR_INPUT_MUX(signal_bit);
} else {
pm_regs.pm07_cntrl[ctr] = 0;
p->bit = signal_bit;
}
for (i = 0; i < NUM_DEBUG_BUS_WORDS; i++) {
if (bus_word & (1 << i)) {
pm_regs.debug_bus_control |=
(bus_type << (30 - (2 * i)));
for (j = 0; j < NUM_INPUT_BUS_WORDS; j++) {
if (input_bus[j] == 0xff) {
input_bus[j] = i;
pm_regs.group_control |=
(i << (30 - (2 * j)));
break;
}
}
}
}
out:
;
}
static void write_pm_cntrl(int cpu)
{
/*
* Oprofile will use 32 bit counters, set bits 7:10 to 0
* pmregs.pm_cntrl is a global
*/
u32 val = 0;
if (pm_regs.pm_cntrl.enable == 1)
val |= CBE_PM_ENABLE_PERF_MON;
if (pm_regs.pm_cntrl.stop_at_max == 1)
val |= CBE_PM_STOP_AT_MAX;
if (pm_regs.pm_cntrl.trace_mode != 0)
val |= CBE_PM_TRACE_MODE_SET(pm_regs.pm_cntrl.trace_mode);
if (pm_regs.pm_cntrl.trace_buf_ovflw == 1)
val |= CBE_PM_TRACE_BUF_OVFLW(pm_regs.pm_cntrl.trace_buf_ovflw);
if (pm_regs.pm_cntrl.freeze == 1)
val |= CBE_PM_FREEZE_ALL_CTRS;
val |= CBE_PM_SPU_ADDR_TRACE_SET(pm_regs.pm_cntrl.spu_addr_trace);
/*
* Routine set_count_mode must be called previously to set
* the count mode based on the user selection of user and kernel.
*/
val |= CBE_PM_COUNT_MODE_SET(pm_regs.pm_cntrl.count_mode);
cbe_write_pm(cpu, pm_control, val);
}
static inline void
set_count_mode(u32 kernel, u32 user)
{
/*
* The user must specify user and kernel if they want them. If
* neither is specified, OProfile will count in hypervisor mode.
* pm_regs.pm_cntrl is a global
*/
if (kernel) {
if (user)
pm_regs.pm_cntrl.count_mode = CBE_COUNT_ALL_MODES;
else
pm_regs.pm_cntrl.count_mode =
CBE_COUNT_SUPERVISOR_MODE;
} else {
if (user)
pm_regs.pm_cntrl.count_mode = CBE_COUNT_PROBLEM_MODE;
else
pm_regs.pm_cntrl.count_mode =
CBE_COUNT_HYPERVISOR_MODE;
}
}
static inline void enable_ctr(u32 cpu, u32 ctr, u32 *pm07_cntrl)
{
pm07_cntrl[ctr] |= CBE_PM_CTR_ENABLE;
cbe_write_pm07_control(cpu, ctr, pm07_cntrl[ctr]);
}
/*
* Oprofile is expected to collect data on all CPUs simultaneously.
* However, there is one set of performance counters per node. There are
* two hardware threads or virtual CPUs on each node. Hence, OProfile must
* multiplex in time the performance counter collection on the two virtual
* CPUs. The multiplexing of the performance counters is done by this
* virtual counter routine.
*
* The pmc_values used below is defined as 'per-cpu' but its use is
* more akin to 'per-node'. We need to store two sets of counter
* values per node -- one for the previous run and one for the next.
* The per-cpu[NR_PHYS_CTRS] gives us the storage we need. Each odd/even
* pair of per-cpu arrays is used for storing the previous and next
* pmc values for a given node.
* NOTE: We use the per-cpu variable to improve cache performance.
*
* This routine will alternate loading the virtual counters for
* virtual CPUs
*/
static void cell_virtual_cntr(unsigned long data)
{
int i, prev_hdw_thread, next_hdw_thread;
u32 cpu;
unsigned long flags;
/*
* Make sure that the interrupt_hander and the virt counter are
* not both playing with the counters on the same node.
*/
spin_lock_irqsave(&cntr_lock, flags);
prev_hdw_thread = hdw_thread;
/* switch the cpu handling the interrupts */
hdw_thread = 1 ^ hdw_thread;
next_hdw_thread = hdw_thread;
pm_regs.group_control = 0;
pm_regs.debug_bus_control = 0;
for (i = 0; i < NUM_INPUT_BUS_WORDS; i++)
input_bus[i] = 0xff;
/*
* There are some per thread events. Must do the
* set event, for the thread that is being started
*/
for (i = 0; i < num_counters; i++)
set_pm_event(i,
pmc_cntrl[next_hdw_thread][i].evnts,
pmc_cntrl[next_hdw_thread][i].masks);
/*
* The following is done only once per each node, but
* we need cpu #, not node #, to pass to the cbe_xxx functions.
*/
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
/*
* stop counters, save counter values, restore counts
* for previous thread
*/
cbe_disable_pm(cpu);
cbe_disable_pm_interrupts(cpu);
for (i = 0; i < num_counters; i++) {
per_cpu(pmc_values, cpu + prev_hdw_thread)[i]
= cbe_read_ctr(cpu, i);
if (per_cpu(pmc_values, cpu + next_hdw_thread)[i]
== 0xFFFFFFFF)
/* If the cntr value is 0xffffffff, we must
* reset that to 0xfffffff0 when the current
* thread is restarted. This will generate a
* new interrupt and make sure that we never
* restore the counters to the max value. If
* the counters were restored to the max value,
* they do not increment and no interrupts are
* generated. Hence no more samples will be
* collected on that cpu.
*/
cbe_write_ctr(cpu, i, 0xFFFFFFF0);
else
cbe_write_ctr(cpu, i,
per_cpu(pmc_values,
cpu +
next_hdw_thread)[i]);
}
/*
* Switch to the other thread. Change the interrupt
* and control regs to be scheduled on the CPU
* corresponding to the thread to execute.
*/
for (i = 0; i < num_counters; i++) {
if (pmc_cntrl[next_hdw_thread][i].enabled) {
/*
* There are some per thread events.
* Must do the set event, enable_cntr
* for each cpu.
*/
enable_ctr(cpu, i,
pm_regs.pm07_cntrl);
} else {
cbe_write_pm07_control(cpu, i, 0);
}
}
/* Enable interrupts on the CPU thread that is starting */
cbe_enable_pm_interrupts(cpu, next_hdw_thread,
virt_cntr_inter_mask);
cbe_enable_pm(cpu);
}
spin_unlock_irqrestore(&cntr_lock, flags);
mod_timer(&timer_virt_cntr, jiffies + HZ / 10);
}
static void start_virt_cntrs(void)
{
init_timer(&timer_virt_cntr);
timer_virt_cntr.function = cell_virtual_cntr;
timer_virt_cntr.data = 0UL;
timer_virt_cntr.expires = jiffies + HZ / 10;
add_timer(&timer_virt_cntr);
}
static int cell_reg_setup_spu_cycles(struct op_counter_config *ctr,
struct op_system_config *sys, int num_ctrs)
{
spu_cycle_reset = ctr[0].count;
/*
* Each node will need to make the rtas call to start
* and stop SPU profiling. Get the token once and store it.
*/
spu_rtas_token = rtas_token("ibm,cbe-spu-perftools");
if (unlikely(spu_rtas_token == RTAS_UNKNOWN_SERVICE)) {
printk(KERN_ERR
"%s: rtas token ibm,cbe-spu-perftools unknown\n",
__func__);
return -EIO;
}
return 0;
}
/* Unfortunately, the hardware will only support event profiling
* on one SPU per node at a time. Therefore, we must time slice
* the profiling across all SPUs in the node. Note, we do this
* in parallel for each node. The following routine is called
* periodically based on kernel timer to switch which SPU is
* being monitored in a round robbin fashion.
*/
static void spu_evnt_swap(unsigned long data)
{
int node;
int cur_phys_spu, nxt_phys_spu, cur_spu_evnt_phys_spu_indx;
unsigned long flags;
int cpu;
int ret;
u32 interrupt_mask;
/* enable interrupts on cntr 0 */
interrupt_mask = CBE_PM_CTR_OVERFLOW_INTR(0);
hdw_thread = 0;
/* Make sure spu event interrupt handler and spu event swap
* don't access the counters simultaneously.
*/
spin_lock_irqsave(&cntr_lock, flags);
cur_spu_evnt_phys_spu_indx = spu_evnt_phys_spu_indx;
if (++(spu_evnt_phys_spu_indx) == NUM_SPUS_PER_NODE)
spu_evnt_phys_spu_indx = 0;
pm_signal[0].sub_unit = spu_evnt_phys_spu_indx;
pm_signal[1].sub_unit = spu_evnt_phys_spu_indx;
pm_signal[2].sub_unit = spu_evnt_phys_spu_indx;
/* switch the SPU being profiled on each node */
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
node = cbe_cpu_to_node(cpu);
cur_phys_spu = (node * NUM_SPUS_PER_NODE)
+ cur_spu_evnt_phys_spu_indx;
nxt_phys_spu = (node * NUM_SPUS_PER_NODE)
+ spu_evnt_phys_spu_indx;
/*
* stop counters, save counter values, restore counts
* for previous physical SPU
*/
cbe_disable_pm(cpu);
cbe_disable_pm_interrupts(cpu);
spu_pm_cnt[cur_phys_spu]
= cbe_read_ctr(cpu, 0);
/* restore previous count for the next spu to sample */
/* NOTE, hardware issue, counter will not start if the
* counter value is at max (0xFFFFFFFF).
*/
if (spu_pm_cnt[nxt_phys_spu] >= 0xFFFFFFFF)
cbe_write_ctr(cpu, 0, 0xFFFFFFF0);
else
cbe_write_ctr(cpu, 0, spu_pm_cnt[nxt_phys_spu]);
pm_rtas_reset_signals(cbe_cpu_to_node(cpu));
/* setup the debug bus measure the one event and
* the two events to route the next SPU's PC on
* the debug bus
*/
ret = pm_rtas_activate_signals(cbe_cpu_to_node(cpu), 3);
if (ret)
printk(KERN_ERR "%s: pm_rtas_activate_signals failed, "
"SPU event swap\n", __func__);
/* clear the trace buffer, don't want to take PC for
* previous SPU*/
cbe_write_pm(cpu, trace_address, 0);
enable_ctr(cpu, 0, pm_regs.pm07_cntrl);
/* Enable interrupts on the CPU thread that is starting */
cbe_enable_pm_interrupts(cpu, hdw_thread,
interrupt_mask);
cbe_enable_pm(cpu);
}
spin_unlock_irqrestore(&cntr_lock, flags);
/* swap approximately every 0.1 seconds */
mod_timer(&timer_spu_event_swap, jiffies + HZ / 25);
}
static void start_spu_event_swap(void)
{
init_timer(&timer_spu_event_swap);
timer_spu_event_swap.function = spu_evnt_swap;
timer_spu_event_swap.data = 0UL;
timer_spu_event_swap.expires = jiffies + HZ / 25;
add_timer(&timer_spu_event_swap);
}
static int cell_reg_setup_spu_events(struct op_counter_config *ctr,
struct op_system_config *sys, int num_ctrs)
{
int i;
/* routine is called once for all nodes */
spu_evnt_phys_spu_indx = 0;
/*
* For all events except PPU CYCLEs, each node will need to make
* the rtas cbe-perftools call to setup and reset the debug bus.
* Make the token lookup call once and store it in the global
* variable pm_rtas_token.
*/
pm_rtas_token = rtas_token("ibm,cbe-perftools");
if (unlikely(pm_rtas_token == RTAS_UNKNOWN_SERVICE)) {
printk(KERN_ERR
"%s: rtas token ibm,cbe-perftools unknown\n",
__func__);
return -EIO;
}
/* setup the pm_control register settings,
* settings will be written per node by the
* cell_cpu_setup() function.
*/
pm_regs.pm_cntrl.trace_buf_ovflw = 1;
/* Use the occurrence trace mode to have SPU PC saved
* to the trace buffer. Occurrence data in trace buffer
* is not used. Bit 2 must be set to store SPU addresses.
*/
pm_regs.pm_cntrl.trace_mode = 2;
pm_regs.pm_cntrl.spu_addr_trace = 0x1; /* using debug bus
event 2 & 3 */
/* setup the debug bus event array with the SPU PC routing events.
* Note, pm_signal[0] will be filled in by set_pm_event() call below.
*/
pm_signal[1].signal_group = SPU_PROFILE_EVENT_ADDR / 100;
pm_signal[1].bus_word = GET_BUS_WORD(SPU_PROFILE_EVENT_ADDR_MASK_A);
pm_signal[1].bit = SPU_PROFILE_EVENT_ADDR % 100;
pm_signal[1].sub_unit = spu_evnt_phys_spu_indx;
pm_signal[2].signal_group = SPU_PROFILE_EVENT_ADDR / 100;
pm_signal[2].bus_word = GET_BUS_WORD(SPU_PROFILE_EVENT_ADDR_MASK_B);
pm_signal[2].bit = SPU_PROFILE_EVENT_ADDR % 100;
pm_signal[2].sub_unit = spu_evnt_phys_spu_indx;
/* Set the user selected spu event to profile on,
* note, only one SPU profiling event is supported
*/
num_counters = 1; /* Only support one SPU event at a time */
set_pm_event(0, ctr[0].event, ctr[0].unit_mask);
reset_value[0] = 0xFFFFFFFF - ctr[0].count;
/* global, used by cell_cpu_setup */
ctr_enabled |= 1;
/* Initialize the count for each SPU to the reset value */
for (i=0; i < MAX_NUMNODES * NUM_SPUS_PER_NODE; i++)
spu_pm_cnt[i] = reset_value[0];
return 0;
}
static int cell_reg_setup_ppu(struct op_counter_config *ctr,
struct op_system_config *sys, int num_ctrs)
{
/* routine is called once for all nodes */
int i, j, cpu;
num_counters = num_ctrs;
if (unlikely(num_ctrs > NR_PHYS_CTRS)) {
printk(KERN_ERR
"%s: Oprofile, number of specified events " \
"exceeds number of physical counters\n",
__func__);
return -EIO;
}
set_count_mode(sys->enable_kernel, sys->enable_user);
/* Setup the thread 0 events */
for (i = 0; i < num_ctrs; ++i) {
pmc_cntrl[0][i].evnts = ctr[i].event;
pmc_cntrl[0][i].masks = ctr[i].unit_mask;
pmc_cntrl[0][i].enabled = ctr[i].enabled;
pmc_cntrl[0][i].vcntr = i;
for_each_possible_cpu(j)
per_cpu(pmc_values, j)[i] = 0;
}
/*
* Setup the thread 1 events, map the thread 0 event to the
* equivalent thread 1 event.
*/
for (i = 0; i < num_ctrs; ++i) {
if ((ctr[i].event >= 2100) && (ctr[i].event <= 2111))
pmc_cntrl[1][i].evnts = ctr[i].event + 19;
else if (ctr[i].event == 2203)
pmc_cntrl[1][i].evnts = ctr[i].event;
else if ((ctr[i].event >= 2200) && (ctr[i].event <= 2215))
pmc_cntrl[1][i].evnts = ctr[i].event + 16;
else
pmc_cntrl[1][i].evnts = ctr[i].event;
pmc_cntrl[1][i].masks = ctr[i].unit_mask;
pmc_cntrl[1][i].enabled = ctr[i].enabled;
pmc_cntrl[1][i].vcntr = i;
}
for (i = 0; i < NUM_INPUT_BUS_WORDS; i++)
input_bus[i] = 0xff;
/*
* Our counters count up, and "count" refers to
* how much before the next interrupt, and we interrupt
* on overflow. So we calculate the starting value
* which will give us "count" until overflow.
* Then we set the events on the enabled counters.
*/
for (i = 0; i < num_counters; ++i) {
/* start with virtual counter set 0 */
if (pmc_cntrl[0][i].enabled) {
/* Using 32bit counters, reset max - count */
reset_value[i] = 0xFFFFFFFF - ctr[i].count;
set_pm_event(i,
pmc_cntrl[0][i].evnts,
pmc_cntrl[0][i].masks);
/* global, used by cell_cpu_setup */
ctr_enabled |= (1 << i);
}
}
/* initialize the previous counts for the virtual cntrs */
for_each_online_cpu(cpu)
for (i = 0; i < num_counters; ++i) {
per_cpu(pmc_values, cpu)[i] = reset_value[i];
}
return 0;
}
/* This function is called once for all cpus combined */
static int cell_reg_setup(struct op_counter_config *ctr,
struct op_system_config *sys, int num_ctrs)
{
int ret=0;
spu_cycle_reset = 0;
/* initialize the spu_arr_trace value, will be reset if
* doing spu event profiling.
*/
pm_regs.group_control = 0;
pm_regs.debug_bus_control = 0;
pm_regs.pm_cntrl.stop_at_max = 1;
pm_regs.pm_cntrl.trace_mode = 0;
pm_regs.pm_cntrl.freeze = 1;
pm_regs.pm_cntrl.trace_buf_ovflw = 0;
pm_regs.pm_cntrl.spu_addr_trace = 0;
/*
* For all events except PPU CYCLEs, each node will need to make
* the rtas cbe-perftools call to setup and reset the debug bus.
* Make the token lookup call once and store it in the global
* variable pm_rtas_token.
*/
pm_rtas_token = rtas_token("ibm,cbe-perftools");
if (unlikely(pm_rtas_token == RTAS_UNKNOWN_SERVICE)) {
printk(KERN_ERR
"%s: rtas token ibm,cbe-perftools unknown\n",
__func__);
return -EIO;
}
if (ctr[0].event == SPU_CYCLES_EVENT_NUM) {
profiling_mode = SPU_PROFILING_CYCLES;
ret = cell_reg_setup_spu_cycles(ctr, sys, num_ctrs);
} else if ((ctr[0].event >= SPU_EVENT_NUM_START) &&
(ctr[0].event <= SPU_EVENT_NUM_STOP)) {
profiling_mode = SPU_PROFILING_EVENTS;
spu_cycle_reset = ctr[0].count;
/* for SPU event profiling, need to setup the
* pm_signal array with the events to route the
* SPU PC before making the FW call. Note, only
* one SPU event for profiling can be specified
* at a time.
*/
cell_reg_setup_spu_events(ctr, sys, num_ctrs);
} else {
profiling_mode = PPU_PROFILING;
ret = cell_reg_setup_ppu(ctr, sys, num_ctrs);
}
return ret;
}
/* This function is called once for each cpu */
static int cell_cpu_setup(struct op_counter_config *cntr)
{
u32 cpu = smp_processor_id();
u32 num_enabled = 0;
int i;
int ret;
/* Cycle based SPU profiling does not use the performance
* counters. The trace array is configured to collect
* the data.
*/
if (profiling_mode == SPU_PROFILING_CYCLES)
return 0;
/* There is one performance monitor per processor chip (i.e. node),
* so we only need to perform this function once per node.
*/
if (cbe_get_hw_thread_id(cpu))
return 0;
/* Stop all counters */
cbe_disable_pm(cpu);
cbe_disable_pm_interrupts(cpu);
cbe_write_pm(cpu, pm_start_stop, 0);
cbe_write_pm(cpu, group_control, pm_regs.group_control);
cbe_write_pm(cpu, debug_bus_control, pm_regs.debug_bus_control);
write_pm_cntrl(cpu);
for (i = 0; i < num_counters; ++i) {
if (ctr_enabled & (1 << i)) {
pm_signal[num_enabled].cpu = cbe_cpu_to_node(cpu);
num_enabled++;
}
}
/*
* The pm_rtas_activate_signals will return -EIO if the FW
* call failed.
*/
if (profiling_mode == SPU_PROFILING_EVENTS) {
/* For SPU event profiling also need to setup the
* pm interval timer
*/
ret = pm_rtas_activate_signals(cbe_cpu_to_node(cpu),
num_enabled+2);
/* store PC from debug bus to Trace buffer as often
* as possible (every 10 cycles)
*/
cbe_write_pm(cpu, pm_interval, NUM_INTERVAL_CYC);
return ret;
} else
return pm_rtas_activate_signals(cbe_cpu_to_node(cpu),
num_enabled);
}
#define ENTRIES 303
#define MAXLFSR 0xFFFFFF
/* precomputed table of 24 bit LFSR values */
static int initial_lfsr[] = {
8221349, 12579195, 5379618, 10097839, 7512963, 7519310, 3955098, 10753424,
15507573, 7458917, 285419, 2641121, 9780088, 3915503, 6668768, 1548716,
4885000, 8774424, 9650099, 2044357, 2304411, 9326253, 10332526, 4421547,
3440748, 10179459, 13332843, 10375561, 1313462, 8375100, 5198480, 6071392,
9341783, 1526887, 3985002, 1439429, 13923762, 7010104, 11969769, 4547026,
2040072, 4025602, 3437678, 7939992, 11444177, 4496094, 9803157, 10745556,
3671780, 4257846, 5662259, 13196905, 3237343, 12077182, 16222879, 7587769,
14706824, 2184640, 12591135, 10420257, 7406075, 3648978, 11042541, 15906893,
11914928, 4732944, 10695697, 12928164, 11980531, 4430912, 11939291, 2917017,
6119256, 4172004, 9373765, 8410071, 14788383, 5047459, 5474428, 1737756,
15967514, 13351758, 6691285, 8034329, 2856544, 14394753, 11310160, 12149558,
7487528, 7542781, 15668898, 12525138, 12790975, 3707933, 9106617, 1965401,
16219109, 12801644, 2443203, 4909502, 8762329, 3120803, 6360315, 9309720,
15164599, 10844842, 4456529, 6667610, 14924259, 884312, 6234963, 3326042,
15973422, 13919464, 5272099, 6414643, 3909029, 2764324, 5237926, 4774955,
10445906, 4955302, 5203726, 10798229, 11443419, 2303395, 333836, 9646934,
3464726, 4159182, 568492, 995747, 10318756, 13299332, 4836017, 8237783,
3878992, 2581665, 11394667, 5672745, 14412947, 3159169, 9094251, 16467278,
8671392, 15230076, 4843545, 7009238, 15504095, 1494895, 9627886, 14485051,
8304291, 252817, 12421642, 16085736, 4774072, 2456177, 4160695, 15409741,
4902868, 5793091, 13162925, 16039714, 782255, 11347835, 14884586, 366972,
16308990, 11913488, 13390465, 2958444, 10340278, 1177858, 1319431, 10426302,
2868597, 126119, 5784857, 5245324, 10903900, 16436004, 3389013, 1742384,
14674502, 10279218, 8536112, 10364279, 6877778, 14051163, 1025130, 6072469,
1988305, 8354440, 8216060, 16342977, 13112639, 3976679, 5913576, 8816697,
6879995, 14043764, 3339515, 9364420, 15808858, 12261651, 2141560, 5636398,
10345425, 10414756, 781725, 6155650, 4746914, 5078683, 7469001, 6799140,
10156444, 9667150, 10116470, 4133858, 2121972, 1124204, 1003577, 1611214,
14304602, 16221850, 13878465, 13577744, 3629235, 8772583, 10881308, 2410386,
7300044, 5378855, 9301235, 12755149, 4977682, 8083074, 10327581, 6395087,
9155434, 15501696, 7514362, 14520507, 15808945, 3244584, 4741962, 9658130,
14336147, 8654727, 7969093, 15759799, 14029445, 5038459, 9894848, 8659300,
13699287, 8834306, 10712885, 14753895, 10410465, 3373251, 309501, 9561475,
5526688, 14647426, 14209836, 5339224, 207299, 14069911, 8722990, 2290950,
3258216, 12505185, 6007317, 9218111, 14661019, 10537428, 11731949, 9027003,
6641507, 9490160, 200241, 9720425, 16277895, 10816638, 1554761, 10431375,
7467528, 6790302, 3429078, 14633753, 14428997, 11463204, 3576212, 2003426,
6123687, 820520, 9992513, 15784513, 5778891, 6428165, 8388607
};
/*
* The hardware uses an LFSR counting sequence to determine when to capture
* the SPU PCs. An LFSR sequence is like a puesdo random number sequence
* where each number occurs once in the sequence but the sequence is not in
* numerical order. The SPU PC capture is done when the LFSR sequence reaches
* the last value in the sequence. Hence the user specified value N
* corresponds to the LFSR number that is N from the end of the sequence.
*
* To avoid the time to compute the LFSR, a lookup table is used. The 24 bit
* LFSR sequence is broken into four ranges. The spacing of the precomputed
* values is adjusted in each range so the error between the user specifed
* number (N) of events between samples and the actual number of events based
* on the precomputed value will be les then about 6.2%. Note, if the user
* specifies N < 2^16, the LFSR value that is 2^16 from the end will be used.
* This is to prevent the loss of samples because the trace buffer is full.
*
* User specified N Step between Index in
* precomputed values precomputed
* table
* 0 to 2^16-1 ---- 0
* 2^16 to 2^16+2^19-1 2^12 1 to 128
* 2^16+2^19 to 2^16+2^19+2^22-1 2^15 129 to 256
* 2^16+2^19+2^22 to 2^24-1 2^18 257 to 302
*
*
* For example, the LFSR values in the second range are computed for 2^16,
* 2^16+2^12, ... , 2^19-2^16, 2^19 and stored in the table at indicies
* 1, 2,..., 127, 128.
*
* The 24 bit LFSR value for the nth number in the sequence can be
* calculated using the following code:
*
* #define size 24
* int calculate_lfsr(int n)
* {
* int i;
* unsigned int newlfsr0;
* unsigned int lfsr = 0xFFFFFF;
* unsigned int howmany = n;
*
* for (i = 2; i < howmany + 2; i++) {
* newlfsr0 = (((lfsr >> (size - 1 - 0)) & 1) ^
* ((lfsr >> (size - 1 - 1)) & 1) ^
* (((lfsr >> (size - 1 - 6)) & 1) ^
* ((lfsr >> (size - 1 - 23)) & 1)));
*
* lfsr >>= 1;
* lfsr = lfsr | (newlfsr0 << (size - 1));
* }
* return lfsr;
* }
*/
#define V2_16 (0x1 << 16)
#define V2_19 (0x1 << 19)
#define V2_22 (0x1 << 22)
static int calculate_lfsr(int n)
{
/*
* The ranges and steps are in powers of 2 so the calculations
* can be done using shifts rather then divide.
*/
int index;
if ((n >> 16) == 0)
index = 0;
else if (((n - V2_16) >> 19) == 0)
index = ((n - V2_16) >> 12) + 1;
else if (((n - V2_16 - V2_19) >> 22) == 0)
index = ((n - V2_16 - V2_19) >> 15 ) + 1 + 128;
else if (((n - V2_16 - V2_19 - V2_22) >> 24) == 0)
index = ((n - V2_16 - V2_19 - V2_22) >> 18 ) + 1 + 256;
else
index = ENTRIES-1;
/* make sure index is valid */
if ((index >= ENTRIES) || (index < 0))
index = ENTRIES-1;
return initial_lfsr[index];
}
static int pm_rtas_activate_spu_profiling(u32 node)
{
int ret, i;
struct pm_signal pm_signal_local[NUM_SPUS_PER_NODE];
/*
* Set up the rtas call to configure the debug bus to
* route the SPU PCs. Setup the pm_signal for each SPU
*/
for (i = 0; i < ARRAY_SIZE(pm_signal_local); i++) {
pm_signal_local[i].cpu = node;
pm_signal_local[i].signal_group = 41;
/* spu i on word (i/2) */
pm_signal_local[i].bus_word = 1 << i / 2;
/* spu i */
pm_signal_local[i].sub_unit = i;
pm_signal_local[i].bit = 63;
}
ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE,
PASSTHRU_ENABLE, pm_signal_local,
(ARRAY_SIZE(pm_signal_local)
* sizeof(struct pm_signal)));
if (unlikely(ret)) {
printk(KERN_WARNING "%s: rtas returned: %d\n",
__func__, ret);
return -EIO;
}
return 0;
}
#ifdef CONFIG_CPU_FREQ
static int
oprof_cpufreq_notify(struct notifier_block *nb, unsigned long val, void *data)
{
int ret = 0;
struct cpufreq_freqs *frq = data;
if ((val == CPUFREQ_PRECHANGE && frq->old < frq->new) ||
(val == CPUFREQ_POSTCHANGE && frq->old > frq->new) ||
(val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE))
set_spu_profiling_frequency(frq->new, spu_cycle_reset);
return ret;
}
static struct notifier_block cpu_freq_notifier_block = {
.notifier_call = oprof_cpufreq_notify
};
#endif
/*
* Note the generic OProfile stop calls do not support returning
* an error on stop. Hence, will not return an error if the FW
* calls fail on stop. Failure to reset the debug bus is not an issue.
* Failure to disable the SPU profiling is not an issue. The FW calls
* to enable the performance counters and debug bus will work even if
* the hardware was not cleanly reset.
*/
static void cell_global_stop_spu_cycles(void)
{
int subfunc, rtn_value;
unsigned int lfsr_value;
int cpu;
oprofile_running = 0;
smp_wmb();
#ifdef CONFIG_CPU_FREQ
cpufreq_unregister_notifier(&cpu_freq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
#endif
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
subfunc = 3; /*
* 2 - activate SPU tracing,
* 3 - deactivate
*/
lfsr_value = 0x8f100000;
rtn_value = rtas_call(spu_rtas_token, 3, 1, NULL,
subfunc, cbe_cpu_to_node(cpu),
lfsr_value);
if (unlikely(rtn_value != 0)) {
printk(KERN_ERR
"%s: rtas call ibm,cbe-spu-perftools " \
"failed, return = %d\n",
__func__, rtn_value);
}
/* Deactivate the signals */
pm_rtas_reset_signals(cbe_cpu_to_node(cpu));
}
stop_spu_profiling_cycles();
}
static void cell_global_stop_spu_events(void)
{
int cpu;
oprofile_running = 0;
stop_spu_profiling_events();
smp_wmb();
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
cbe_sync_irq(cbe_cpu_to_node(cpu));
/* Stop the counters */
cbe_disable_pm(cpu);
cbe_write_pm07_control(cpu, 0, 0);
/* Deactivate the signals */
pm_rtas_reset_signals(cbe_cpu_to_node(cpu));
/* Deactivate interrupts */
cbe_disable_pm_interrupts(cpu);
}
del_timer_sync(&timer_spu_event_swap);
}
static void cell_global_stop_ppu(void)
{
int cpu;
/*
* This routine will be called once for the system.
* There is one performance monitor per node, so we
* only need to perform this function once per node.
*/
del_timer_sync(&timer_virt_cntr);
oprofile_running = 0;
smp_wmb();
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
cbe_sync_irq(cbe_cpu_to_node(cpu));
/* Stop the counters */
cbe_disable_pm(cpu);
/* Deactivate the signals */
pm_rtas_reset_signals(cbe_cpu_to_node(cpu));
/* Deactivate interrupts */
cbe_disable_pm_interrupts(cpu);
}
}
static void cell_global_stop(void)
{
if (profiling_mode == PPU_PROFILING)
cell_global_stop_ppu();
else if (profiling_mode == SPU_PROFILING_EVENTS)
cell_global_stop_spu_events();
else
cell_global_stop_spu_cycles();
}
static int cell_global_start_spu_cycles(struct op_counter_config *ctr)
{
int subfunc;
unsigned int lfsr_value;
int cpu;
int ret;
int rtas_error;
unsigned int cpu_khzfreq = 0;
/* The SPU profiling uses time-based profiling based on
* cpu frequency, so if configured with the CPU_FREQ
* option, we should detect frequency changes and react
* accordingly.
*/
#ifdef CONFIG_CPU_FREQ
ret = cpufreq_register_notifier(&cpu_freq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
if (ret < 0)
/* this is not a fatal error */
printk(KERN_ERR "CPU freq change registration failed: %d\n",
ret);
else
cpu_khzfreq = cpufreq_quick_get(smp_processor_id());
#endif
set_spu_profiling_frequency(cpu_khzfreq, spu_cycle_reset);
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
/*
* Setup SPU cycle-based profiling.
* Set perf_mon_control bit 0 to a zero before
* enabling spu collection hardware.
*/
cbe_write_pm(cpu, pm_control, 0);
if (spu_cycle_reset > MAX_SPU_COUNT)
/* use largest possible value */
lfsr_value = calculate_lfsr(MAX_SPU_COUNT-1);
else
lfsr_value = calculate_lfsr(spu_cycle_reset);
/* must use a non zero value. Zero disables data collection. */
if (lfsr_value == 0)
lfsr_value = calculate_lfsr(1);
lfsr_value = lfsr_value << 8; /* shift lfsr to correct
* register location
*/
/* debug bus setup */
ret = pm_rtas_activate_spu_profiling(cbe_cpu_to_node(cpu));
if (unlikely(ret)) {
rtas_error = ret;
goto out;
}
subfunc = 2; /* 2 - activate SPU tracing, 3 - deactivate */
/* start profiling */
ret = rtas_call(spu_rtas_token, 3, 1, NULL, subfunc,
cbe_cpu_to_node(cpu), lfsr_value);
if (unlikely(ret != 0)) {
printk(KERN_ERR
"%s: rtas call ibm,cbe-spu-perftools failed, " \
"return = %d\n", __func__, ret);
rtas_error = -EIO;
goto out;
}
}
rtas_error = start_spu_profiling_cycles(spu_cycle_reset);
if (rtas_error)
goto out_stop;
oprofile_running = 1;
return 0;
out_stop:
cell_global_stop_spu_cycles(); /* clean up the PMU/debug bus */
out:
return rtas_error;
}
static int cell_global_start_spu_events(struct op_counter_config *ctr)
{
int cpu;
u32 interrupt_mask = 0;
int rtn = 0;
hdw_thread = 0;
/* spu event profiling, uses the performance counters to generate
* an interrupt. The hardware is setup to store the SPU program
* counter into the trace array. The occurrence mode is used to
* enable storing data to the trace buffer. The bits are set
* to send/store the SPU address in the trace buffer. The debug
* bus must be setup to route the SPU program counter onto the
* debug bus. The occurrence data in the trace buffer is not used.
*/
/* This routine gets called once for the system.
* There is one performance monitor per node, so we
* only need to perform this function once per node.
*/
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
/*
* Setup SPU event-based profiling.
* Set perf_mon_control bit 0 to a zero before
* enabling spu collection hardware.
*
* Only support one SPU event on one SPU per node.
*/
if (ctr_enabled & 1) {
cbe_write_ctr(cpu, 0, reset_value[0]);
enable_ctr(cpu, 0, pm_regs.pm07_cntrl);
interrupt_mask |=
CBE_PM_CTR_OVERFLOW_INTR(0);
} else {
/* Disable counter */
cbe_write_pm07_control(cpu, 0, 0);
}
cbe_get_and_clear_pm_interrupts(cpu);
cbe_enable_pm_interrupts(cpu, hdw_thread, interrupt_mask);
cbe_enable_pm(cpu);
/* clear the trace buffer */
cbe_write_pm(cpu, trace_address, 0);
}
/* Start the timer to time slice collecting the event profile
* on each of the SPUs. Note, can collect profile on one SPU
* per node at a time.
*/
start_spu_event_swap();
start_spu_profiling_events();
oprofile_running = 1;
smp_wmb();
return rtn;
}
static int cell_global_start_ppu(struct op_counter_config *ctr)
{
u32 cpu, i;
u32 interrupt_mask = 0;
/* This routine gets called once for the system.
* There is one performance monitor per node, so we
* only need to perform this function once per node.
*/
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
interrupt_mask = 0;
for (i = 0; i < num_counters; ++i) {
if (ctr_enabled & (1 << i)) {
cbe_write_ctr(cpu, i, reset_value[i]);
enable_ctr(cpu, i, pm_regs.pm07_cntrl);
interrupt_mask |= CBE_PM_CTR_OVERFLOW_INTR(i);
} else {
/* Disable counter */
cbe_write_pm07_control(cpu, i, 0);
}
}
cbe_get_and_clear_pm_interrupts(cpu);
cbe_enable_pm_interrupts(cpu, hdw_thread, interrupt_mask);
cbe_enable_pm(cpu);
}
virt_cntr_inter_mask = interrupt_mask;
oprofile_running = 1;
smp_wmb();
/*
* NOTE: start_virt_cntrs will result in cell_virtual_cntr() being
* executed which manipulates the PMU. We start the "virtual counter"
* here so that we do not need to synchronize access to the PMU in
* the above for-loop.
*/
start_virt_cntrs();
return 0;
}
static int cell_global_start(struct op_counter_config *ctr)
{
if (profiling_mode == SPU_PROFILING_CYCLES)
return cell_global_start_spu_cycles(ctr);
else if (profiling_mode == SPU_PROFILING_EVENTS)
return cell_global_start_spu_events(ctr);
else
return cell_global_start_ppu(ctr);
}
/* The SPU interrupt handler
*
* SPU event profiling works as follows:
* The pm_signal[0] holds the one SPU event to be measured. It is routed on
* the debug bus using word 0 or 1. The value of pm_signal[1] and
* pm_signal[2] contain the necessary events to route the SPU program
* counter for the selected SPU onto the debug bus using words 2 and 3.
* The pm_interval register is setup to write the SPU PC value into the
* trace buffer at the maximum rate possible. The trace buffer is configured
* to store the PCs, wrapping when it is full. The performance counter is
* initialized to the max hardware count minus the number of events, N, between
* samples. Once the N events have occurred, a HW counter overflow occurs
* causing the generation of a HW counter interrupt which also stops the
* writing of the SPU PC values to the trace buffer. Hence the last PC
* written to the trace buffer is the SPU PC that we want. Unfortunately,
* we have to read from the beginning of the trace buffer to get to the
* last value written. We just hope the PPU has nothing better to do then
* service this interrupt. The PC for the specific SPU being profiled is
* extracted from the trace buffer processed and stored. The trace buffer
* is cleared, interrupts are cleared, the counter is reset to max - N.
* A kernel timer is used to periodically call the routine spu_evnt_swap()
* to switch to the next physical SPU in the node to profile in round robbin
* order. This way data is collected for all SPUs on the node. It does mean
* that we need to use a relatively small value of N to ensure enough samples
* on each SPU are collected each SPU is being profiled 1/8 of the time.
* It may also be necessary to use a longer sample collection period.
*/
static void cell_handle_interrupt_spu(struct pt_regs *regs,
struct op_counter_config *ctr)
{
u32 cpu, cpu_tmp;
u64 trace_entry;
u32 interrupt_mask;
u64 trace_buffer[2];
u64 last_trace_buffer;
u32 sample;
u32 trace_addr;
unsigned long sample_array_lock_flags;
int spu_num;
unsigned long flags;
/* Make sure spu event interrupt handler and spu event swap
* don't access the counters simultaneously.
*/
cpu = smp_processor_id();
spin_lock_irqsave(&cntr_lock, flags);
cpu_tmp = cpu;
cbe_disable_pm(cpu);
interrupt_mask = cbe_get_and_clear_pm_interrupts(cpu);
sample = 0xABCDEF;
trace_entry = 0xfedcba;
last_trace_buffer = 0xdeadbeaf;
if ((oprofile_running == 1) && (interrupt_mask != 0)) {
/* disable writes to trace buff */
cbe_write_pm(cpu, pm_interval, 0);
/* only have one perf cntr being used, cntr 0 */
if ((interrupt_mask & CBE_PM_CTR_OVERFLOW_INTR(0))
&& ctr[0].enabled)
/* The SPU PC values will be read
* from the trace buffer, reset counter
*/
cbe_write_ctr(cpu, 0, reset_value[0]);
trace_addr = cbe_read_pm(cpu, trace_address);
while (!(trace_addr & CBE_PM_TRACE_BUF_EMPTY)) {
/* There is data in the trace buffer to process
* Read the buffer until you get to the last
* entry. This is the value we want.
*/
cbe_read_trace_buffer(cpu, trace_buffer);
trace_addr = cbe_read_pm(cpu, trace_address);
}
/* SPU Address 16 bit count format for 128 bit
* HW trace buffer is used for the SPU PC storage
* HDR bits 0:15
* SPU Addr 0 bits 16:31
* SPU Addr 1 bits 32:47
* unused bits 48:127
*
* HDR: bit4 = 1 SPU Address 0 valid
* HDR: bit5 = 1 SPU Address 1 valid
* - unfortunately, the valid bits don't seem to work
*
* Note trace_buffer[0] holds bits 0:63 of the HW
* trace buffer, trace_buffer[1] holds bits 64:127
*/
trace_entry = trace_buffer[0]
& 0x00000000FFFF0000;
/* only top 16 of the 18 bit SPU PC address
* is stored in trace buffer, hence shift right
* by 16 -2 bits */
sample = trace_entry >> 14;
last_trace_buffer = trace_buffer[0];
spu_num = spu_evnt_phys_spu_indx
+ (cbe_cpu_to_node(cpu) * NUM_SPUS_PER_NODE);
/* make sure only one process at a time is calling
* spu_sync_buffer()
*/
spin_lock_irqsave(&oprof_spu_smpl_arry_lck,
sample_array_lock_flags);
spu_sync_buffer(spu_num, &sample, 1);
spin_unlock_irqrestore(&oprof_spu_smpl_arry_lck,
sample_array_lock_flags);
smp_wmb(); /* insure spu event buffer updates are written
* don't want events intermingled... */
/* The counters were frozen by the interrupt.
* Reenable the interrupt and restart the counters.
*/
cbe_write_pm(cpu, pm_interval, NUM_INTERVAL_CYC);
cbe_enable_pm_interrupts(cpu, hdw_thread,
virt_cntr_inter_mask);
/* clear the trace buffer, re-enable writes to trace buff */
cbe_write_pm(cpu, trace_address, 0);
cbe_write_pm(cpu, pm_interval, NUM_INTERVAL_CYC);
/* The writes to the various performance counters only writes
* to a latch. The new values (interrupt setting bits, reset
* counter value etc.) are not copied to the actual registers
* until the performance monitor is enabled. In order to get
* this to work as desired, the performance monitor needs to
* be disabled while writing to the latches. This is a
* HW design issue.
*/
write_pm_cntrl(cpu);
cbe_enable_pm(cpu);
}
spin_unlock_irqrestore(&cntr_lock, flags);
}
static void cell_handle_interrupt_ppu(struct pt_regs *regs,
struct op_counter_config *ctr)
{
u32 cpu;
u64 pc;
int is_kernel;
unsigned long flags = 0;
u32 interrupt_mask;
int i;
cpu = smp_processor_id();
/*
* Need to make sure the interrupt handler and the virt counter
* routine are not running at the same time. See the
* cell_virtual_cntr() routine for additional comments.
*/
spin_lock_irqsave(&cntr_lock, flags);
/*
* Need to disable and reenable the performance counters
* to get the desired behavior from the hardware. This
* is hardware specific.
*/
cbe_disable_pm(cpu);
interrupt_mask = cbe_get_and_clear_pm_interrupts(cpu);
/*
* If the interrupt mask has been cleared, then the virt cntr
* has cleared the interrupt. When the thread that generated
* the interrupt is restored, the data count will be restored to
* 0xffffff0 to cause the interrupt to be regenerated.
*/
if ((oprofile_running == 1) && (interrupt_mask != 0)) {
pc = regs->nip;
is_kernel = is_kernel_addr(pc);
for (i = 0; i < num_counters; ++i) {
if ((interrupt_mask & CBE_PM_CTR_OVERFLOW_INTR(i))
&& ctr[i].enabled) {
oprofile_add_ext_sample(pc, regs, i, is_kernel);
cbe_write_ctr(cpu, i, reset_value[i]);
}
}
/*
* The counters were frozen by the interrupt.
* Reenable the interrupt and restart the counters.
* If there was a race between the interrupt handler and
* the virtual counter routine. The virtual counter
* routine may have cleared the interrupts. Hence must
* use the virt_cntr_inter_mask to re-enable the interrupts.
*/
cbe_enable_pm_interrupts(cpu, hdw_thread,
virt_cntr_inter_mask);
/*
* The writes to the various performance counters only writes
* to a latch. The new values (interrupt setting bits, reset
* counter value etc.) are not copied to the actual registers
* until the performance monitor is enabled. In order to get
* this to work as desired, the performance monitor needs to
* be disabled while writing to the latches. This is a
* HW design issue.
*/
cbe_enable_pm(cpu);
}
spin_unlock_irqrestore(&cntr_lock, flags);
}
static void cell_handle_interrupt(struct pt_regs *regs,
struct op_counter_config *ctr)
{
if (profiling_mode == PPU_PROFILING)
cell_handle_interrupt_ppu(regs, ctr);
else
cell_handle_interrupt_spu(regs, ctr);
}
/*
* This function is called from the generic OProfile
* driver. When profiling PPUs, we need to do the
* generic sync start; otherwise, do spu_sync_start.
*/
static int cell_sync_start(void)
{
if ((profiling_mode == SPU_PROFILING_CYCLES) ||
(profiling_mode == SPU_PROFILING_EVENTS))
return spu_sync_start();
else
return DO_GENERIC_SYNC;
}
static int cell_sync_stop(void)
{
if ((profiling_mode == SPU_PROFILING_CYCLES) ||
(profiling_mode == SPU_PROFILING_EVENTS))
return spu_sync_stop();
else
return 1;
}
struct op_powerpc_model op_model_cell = {
.reg_setup = cell_reg_setup,
.cpu_setup = cell_cpu_setup,
.global_start = cell_global_start,
.global_stop = cell_global_stop,
.sync_start = cell_sync_start,
.sync_stop = cell_sync_stop,
.handle_interrupt = cell_handle_interrupt,
};