- 根目录:
- drivers
- parisc
- sba_iommu.c
/*
** System Bus Adapter (SBA) I/O MMU manager
**
** (c) Copyright 2000-2004 Grant Grundler <grundler @ parisc-linux x org>
** (c) Copyright 2004 Naresh Kumar Inna <knaresh at india x hp x com>
** (c) Copyright 2000-2004 Hewlett-Packard Company
**
** Portions (c) 1999 Dave S. Miller (from sparc64 I/O MMU code)
**
** 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.
**
**
** This module initializes the IOC (I/O Controller) found on B1000/C3000/
** J5000/J7000/N-class/L-class machines and their successors.
**
** FIXME: add DMA hint support programming in both sba and lba modules.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/scatterlist.h>
#include <linux/iommu-helper.h>
#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/dma.h> /* for DMA_CHUNK_SIZE */
#include <asm/hardware.h> /* for register_parisc_driver() stuff */
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <asm/ropes.h>
#include <asm/mckinley.h> /* for proc_mckinley_root */
#include <asm/runway.h> /* for proc_runway_root */
#include <asm/page.h> /* for PAGE0 */
#include <asm/pdc.h> /* for PDC_MODEL_* */
#include <asm/pdcpat.h> /* for is_pdc_pat() */
#include <asm/parisc-device.h>
#define MODULE_NAME "SBA"
/*
** The number of debug flags is a clue - this code is fragile.
** Don't even think about messing with it unless you have
** plenty of 710's to sacrifice to the computer gods. :^)
*/
#undef DEBUG_SBA_INIT
#undef DEBUG_SBA_RUN
#undef DEBUG_SBA_RUN_SG
#undef DEBUG_SBA_RESOURCE
#undef ASSERT_PDIR_SANITY
#undef DEBUG_LARGE_SG_ENTRIES
#undef DEBUG_DMB_TRAP
#ifdef DEBUG_SBA_INIT
#define DBG_INIT(x...) printk(x)
#else
#define DBG_INIT(x...)
#endif
#ifdef DEBUG_SBA_RUN
#define DBG_RUN(x...) printk(x)
#else
#define DBG_RUN(x...)
#endif
#ifdef DEBUG_SBA_RUN_SG
#define DBG_RUN_SG(x...) printk(x)
#else
#define DBG_RUN_SG(x...)
#endif
#ifdef DEBUG_SBA_RESOURCE
#define DBG_RES(x...) printk(x)
#else
#define DBG_RES(x...)
#endif
#define SBA_INLINE __inline__
#define DEFAULT_DMA_HINT_REG 0
struct sba_device *sba_list;
EXPORT_SYMBOL_GPL(sba_list);
static unsigned long ioc_needs_fdc = 0;
/* global count of IOMMUs in the system */
static unsigned int global_ioc_cnt = 0;
/* PA8700 (Piranha 2.2) bug workaround */
static unsigned long piranha_bad_128k = 0;
/* Looks nice and keeps the compiler happy */
#define SBA_DEV(d) ((struct sba_device *) (d))
#ifdef CONFIG_AGP_PARISC
#define SBA_AGP_SUPPORT
#endif /*CONFIG_AGP_PARISC*/
#ifdef SBA_AGP_SUPPORT
static int sba_reserve_agpgart = 1;
module_param(sba_reserve_agpgart, int, 0444);
MODULE_PARM_DESC(sba_reserve_agpgart, "Reserve half of IO pdir as AGPGART");
#endif
/************************************
** SBA register read and write support
**
** BE WARNED: register writes are posted.
** (ie follow writes which must reach HW with a read)
**
** Superdome (in particular, REO) allows only 64-bit CSR accesses.
*/
#define READ_REG32(addr) readl(addr)
#define READ_REG64(addr) readq(addr)
#define WRITE_REG32(val, addr) writel((val), (addr))
#define WRITE_REG64(val, addr) writeq((val), (addr))
#ifdef CONFIG_64BIT
#define READ_REG(addr) READ_REG64(addr)
#define WRITE_REG(value, addr) WRITE_REG64(value, addr)
#else
#define READ_REG(addr) READ_REG32(addr)
#define WRITE_REG(value, addr) WRITE_REG32(value, addr)
#endif
#ifdef DEBUG_SBA_INIT
/* NOTE: When CONFIG_64BIT isn't defined, READ_REG64() is two 32-bit reads */
/**
* sba_dump_ranges - debugging only - print ranges assigned to this IOA
* @hpa: base address of the sba
*
* Print the MMIO and IO Port address ranges forwarded by an Astro/Ike/RIO
* IO Adapter (aka Bus Converter).
*/
static void
sba_dump_ranges(void __iomem *hpa)
{
DBG_INIT("SBA at 0x%p\n", hpa);
DBG_INIT("IOS_DIST_BASE : %Lx\n", READ_REG64(hpa+IOS_DIST_BASE));
DBG_INIT("IOS_DIST_MASK : %Lx\n", READ_REG64(hpa+IOS_DIST_MASK));
DBG_INIT("IOS_DIST_ROUTE : %Lx\n", READ_REG64(hpa+IOS_DIST_ROUTE));
DBG_INIT("\n");
DBG_INIT("IOS_DIRECT_BASE : %Lx\n", READ_REG64(hpa+IOS_DIRECT_BASE));
DBG_INIT("IOS_DIRECT_MASK : %Lx\n", READ_REG64(hpa+IOS_DIRECT_MASK));
DBG_INIT("IOS_DIRECT_ROUTE: %Lx\n", READ_REG64(hpa+IOS_DIRECT_ROUTE));
}
/**
* sba_dump_tlb - debugging only - print IOMMU operating parameters
* @hpa: base address of the IOMMU
*
* Print the size/location of the IO MMU PDIR.
*/
static void sba_dump_tlb(void __iomem *hpa)
{
DBG_INIT("IO TLB at 0x%p\n", hpa);
DBG_INIT("IOC_IBASE : 0x%Lx\n", READ_REG64(hpa+IOC_IBASE));
DBG_INIT("IOC_IMASK : 0x%Lx\n", READ_REG64(hpa+IOC_IMASK));
DBG_INIT("IOC_TCNFG : 0x%Lx\n", READ_REG64(hpa+IOC_TCNFG));
DBG_INIT("IOC_PDIR_BASE: 0x%Lx\n", READ_REG64(hpa+IOC_PDIR_BASE));
DBG_INIT("\n");
}
#else
#define sba_dump_ranges(x)
#define sba_dump_tlb(x)
#endif /* DEBUG_SBA_INIT */
#ifdef ASSERT_PDIR_SANITY
/**
* sba_dump_pdir_entry - debugging only - print one IOMMU PDIR entry
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @msg: text to print ont the output line.
* @pide: pdir index.
*
* Print one entry of the IO MMU PDIR in human readable form.
*/
static void
sba_dump_pdir_entry(struct ioc *ioc, char *msg, uint pide)
{
/* start printing from lowest pde in rval */
u64 *ptr = &(ioc->pdir_base[pide & (~0U * BITS_PER_LONG)]);
unsigned long *rptr = (unsigned long *) &(ioc->res_map[(pide >>3) & ~(sizeof(unsigned long) - 1)]);
uint rcnt;
printk(KERN_DEBUG "SBA: %s rp %p bit %d rval 0x%lx\n",
msg,
rptr, pide & (BITS_PER_LONG - 1), *rptr);
rcnt = 0;
while (rcnt < BITS_PER_LONG) {
printk(KERN_DEBUG "%s %2d %p %016Lx\n",
(rcnt == (pide & (BITS_PER_LONG - 1)))
? " -->" : " ",
rcnt, ptr, *ptr );
rcnt++;
ptr++;
}
printk(KERN_DEBUG "%s", msg);
}
/**
* sba_check_pdir - debugging only - consistency checker
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @msg: text to print ont the output line.
*
* Verify the resource map and pdir state is consistent
*/
static int
sba_check_pdir(struct ioc *ioc, char *msg)
{
u32 *rptr_end = (u32 *) &(ioc->res_map[ioc->res_size]);
u32 *rptr = (u32 *) ioc->res_map; /* resource map ptr */
u64 *pptr = ioc->pdir_base; /* pdir ptr */
uint pide = 0;
while (rptr < rptr_end) {
u32 rval = *rptr;
int rcnt = 32; /* number of bits we might check */
while (rcnt) {
/* Get last byte and highest bit from that */
u32 pde = ((u32) (((char *)pptr)[7])) << 24;
if ((rval ^ pde) & 0x80000000)
{
/*
** BUMMER! -- res_map != pdir --
** Dump rval and matching pdir entries
*/
sba_dump_pdir_entry(ioc, msg, pide);
return(1);
}
rcnt--;
rval <<= 1; /* try the next bit */
pptr++;
pide++;
}
rptr++; /* look at next word of res_map */
}
/* It'd be nice if we always got here :^) */
return 0;
}
/**
* sba_dump_sg - debugging only - print Scatter-Gather list
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @startsg: head of the SG list
* @nents: number of entries in SG list
*
* print the SG list so we can verify it's correct by hand.
*/
static void
sba_dump_sg( struct ioc *ioc, struct scatterlist *startsg, int nents)
{
while (nents-- > 0) {
printk(KERN_DEBUG " %d : %08lx/%05x %p/%05x\n",
nents,
(unsigned long) sg_dma_address(startsg),
sg_dma_len(startsg),
sg_virt(startsg), startsg->length);
startsg++;
}
}
#endif /* ASSERT_PDIR_SANITY */
/**************************************************************
*
* I/O Pdir Resource Management
*
* Bits set in the resource map are in use.
* Each bit can represent a number of pages.
* LSbs represent lower addresses (IOVA's).
*
***************************************************************/
#define PAGES_PER_RANGE 1 /* could increase this to 4 or 8 if needed */
/* Convert from IOVP to IOVA and vice versa. */
#ifdef ZX1_SUPPORT
/* Pluto (aka ZX1) boxes need to set or clear the ibase bits appropriately */
#define SBA_IOVA(ioc,iovp,offset,hint_reg) ((ioc->ibase) | (iovp) | (offset))
#define SBA_IOVP(ioc,iova) ((iova) & (ioc)->iovp_mask)
#else
/* only support Astro and ancestors. Saves a few cycles in key places */
#define SBA_IOVA(ioc,iovp,offset,hint_reg) ((iovp) | (offset))
#define SBA_IOVP(ioc,iova) (iova)
#endif
#define PDIR_INDEX(iovp) ((iovp)>>IOVP_SHIFT)
#define RESMAP_MASK(n) (~0UL << (BITS_PER_LONG - (n)))
#define RESMAP_IDX_MASK (sizeof(unsigned long) - 1)
static unsigned long ptr_to_pide(struct ioc *ioc, unsigned long *res_ptr,
unsigned int bitshiftcnt)
{
return (((unsigned long)res_ptr - (unsigned long)ioc->res_map) << 3)
+ bitshiftcnt;
}
/**
* sba_search_bitmap - find free space in IO PDIR resource bitmap
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @bits_wanted: number of entries we need.
*
* Find consecutive free bits in resource bitmap.
* Each bit represents one entry in the IO Pdir.
* Cool perf optimization: search for log2(size) bits at a time.
*/
static SBA_INLINE unsigned long
sba_search_bitmap(struct ioc *ioc, struct device *dev,
unsigned long bits_wanted)
{
unsigned long *res_ptr = ioc->res_hint;
unsigned long *res_end = (unsigned long *) &(ioc->res_map[ioc->res_size]);
unsigned long pide = ~0UL, tpide;
unsigned long boundary_size;
unsigned long shift;
int ret;
boundary_size = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1,
1ULL << IOVP_SHIFT) >> IOVP_SHIFT;
#if defined(ZX1_SUPPORT)
BUG_ON(ioc->ibase & ~IOVP_MASK);
shift = ioc->ibase >> IOVP_SHIFT;
#else
shift = 0;
#endif
if (bits_wanted > (BITS_PER_LONG/2)) {
/* Search word at a time - no mask needed */
for(; res_ptr < res_end; ++res_ptr) {
tpide = ptr_to_pide(ioc, res_ptr, 0);
ret = iommu_is_span_boundary(tpide, bits_wanted,
shift,
boundary_size);
if ((*res_ptr == 0) && !ret) {
*res_ptr = RESMAP_MASK(bits_wanted);
pide = tpide;
break;
}
}
/* point to the next word on next pass */
res_ptr++;
ioc->res_bitshift = 0;
} else {
/*
** Search the resource bit map on well-aligned values.
** "o" is the alignment.
** We need the alignment to invalidate I/O TLB using
** SBA HW features in the unmap path.
*/
unsigned long o = 1 << get_order(bits_wanted << PAGE_SHIFT);
uint bitshiftcnt = ALIGN(ioc->res_bitshift, o);
unsigned long mask;
if (bitshiftcnt >= BITS_PER_LONG) {
bitshiftcnt = 0;
res_ptr++;
}
mask = RESMAP_MASK(bits_wanted) >> bitshiftcnt;
DBG_RES("%s() o %ld %p", __func__, o, res_ptr);
while(res_ptr < res_end)
{
DBG_RES(" %p %lx %lx\n", res_ptr, mask, *res_ptr);
WARN_ON(mask == 0);
tpide = ptr_to_pide(ioc, res_ptr, bitshiftcnt);
ret = iommu_is_span_boundary(tpide, bits_wanted,
shift,
boundary_size);
if ((((*res_ptr) & mask) == 0) && !ret) {
*res_ptr |= mask; /* mark resources busy! */
pide = tpide;
break;
}
mask >>= o;
bitshiftcnt += o;
if (mask == 0) {
mask = RESMAP_MASK(bits_wanted);
bitshiftcnt=0;
res_ptr++;
}
}
/* look in the same word on the next pass */
ioc->res_bitshift = bitshiftcnt + bits_wanted;
}
/* wrapped ? */
if (res_end <= res_ptr) {
ioc->res_hint = (unsigned long *) ioc->res_map;
ioc->res_bitshift = 0;
} else {
ioc->res_hint = res_ptr;
}
return (pide);
}
/**
* sba_alloc_range - find free bits and mark them in IO PDIR resource bitmap
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @size: number of bytes to create a mapping for
*
* Given a size, find consecutive unmarked and then mark those bits in the
* resource bit map.
*/
static int
sba_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
{
unsigned int pages_needed = size >> IOVP_SHIFT;
#ifdef SBA_COLLECT_STATS
unsigned long cr_start = mfctl(16);
#endif
unsigned long pide;
pide = sba_search_bitmap(ioc, dev, pages_needed);
if (pide >= (ioc->res_size << 3)) {
pide = sba_search_bitmap(ioc, dev, pages_needed);
if (pide >= (ioc->res_size << 3))
panic("%s: I/O MMU @ %p is out of mapping resources\n",
__FILE__, ioc->ioc_hpa);
}
#ifdef ASSERT_PDIR_SANITY
/* verify the first enable bit is clear */
if(0x00 != ((u8 *) ioc->pdir_base)[pide*sizeof(u64) + 7]) {
sba_dump_pdir_entry(ioc, "sba_search_bitmap() botched it?", pide);
}
#endif
DBG_RES("%s(%x) %d -> %lx hint %x/%x\n",
__func__, size, pages_needed, pide,
(uint) ((unsigned long) ioc->res_hint - (unsigned long) ioc->res_map),
ioc->res_bitshift );
#ifdef SBA_COLLECT_STATS
{
unsigned long cr_end = mfctl(16);
unsigned long tmp = cr_end - cr_start;
/* check for roll over */
cr_start = (cr_end < cr_start) ? -(tmp) : (tmp);
}
ioc->avg_search[ioc->avg_idx++] = cr_start;
ioc->avg_idx &= SBA_SEARCH_SAMPLE - 1;
ioc->used_pages += pages_needed;
#endif
return (pide);
}
/**
* sba_free_range - unmark bits in IO PDIR resource bitmap
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @iova: IO virtual address which was previously allocated.
* @size: number of bytes to create a mapping for
*
* clear bits in the ioc's resource map
*/
static SBA_INLINE void
sba_free_range(struct ioc *ioc, dma_addr_t iova, size_t size)
{
unsigned long iovp = SBA_IOVP(ioc, iova);
unsigned int pide = PDIR_INDEX(iovp);
unsigned int ridx = pide >> 3; /* convert bit to byte address */
unsigned long *res_ptr = (unsigned long *) &((ioc)->res_map[ridx & ~RESMAP_IDX_MASK]);
int bits_not_wanted = size >> IOVP_SHIFT;
/* 3-bits "bit" address plus 2 (or 3) bits for "byte" == bit in word */
unsigned long m = RESMAP_MASK(bits_not_wanted) >> (pide & (BITS_PER_LONG - 1));
DBG_RES("%s( ,%x,%x) %x/%lx %x %p %lx\n",
__func__, (uint) iova, size,
bits_not_wanted, m, pide, res_ptr, *res_ptr);
#ifdef SBA_COLLECT_STATS
ioc->used_pages -= bits_not_wanted;
#endif
*res_ptr &= ~m;
}
/**************************************************************
*
* "Dynamic DMA Mapping" support (aka "Coherent I/O")
*
***************************************************************/
#ifdef SBA_HINT_SUPPORT
#define SBA_DMA_HINT(ioc, val) ((val) << (ioc)->hint_shift_pdir)
#endif
typedef unsigned long space_t;
#define KERNEL_SPACE 0
/**
* sba_io_pdir_entry - fill in one IO PDIR entry
* @pdir_ptr: pointer to IO PDIR entry
* @sid: process Space ID - currently only support KERNEL_SPACE
* @vba: Virtual CPU address of buffer to map
* @hint: DMA hint set to use for this mapping
*
* SBA Mapping Routine
*
* Given a virtual address (vba, arg2) and space id, (sid, arg1)
* sba_io_pdir_entry() loads the I/O PDIR entry pointed to by
* pdir_ptr (arg0).
* Using the bass-ackwards HP bit numbering, Each IO Pdir entry
* for Astro/Ike looks like:
*
*
* 0 19 51 55 63
* +-+---------------------+----------------------------------+----+--------+
* |V| U | PPN[43:12] | U | VI |
* +-+---------------------+----------------------------------+----+--------+
*
* Pluto is basically identical, supports fewer physical address bits:
*
* 0 23 51 55 63
* +-+------------------------+-------------------------------+----+--------+
* |V| U | PPN[39:12] | U | VI |
* +-+------------------------+-------------------------------+----+--------+
*
* V == Valid Bit (Most Significant Bit is bit 0)
* U == Unused
* PPN == Physical Page Number
* VI == Virtual Index (aka Coherent Index)
*
* LPA instruction output is put into PPN field.
* LCI (Load Coherence Index) instruction provides the "VI" bits.
*
* We pre-swap the bytes since PCX-W is Big Endian and the
* IOMMU uses little endian for the pdir.
*/
static void SBA_INLINE
sba_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
unsigned long hint)
{
u64 pa; /* physical address */
register unsigned ci; /* coherent index */
pa = virt_to_phys(vba);
pa &= IOVP_MASK;
mtsp(sid,1);
asm("lci 0(%%sr1, %1), %0" : "=r" (ci) : "r" (vba));
pa |= (ci >> PAGE_SHIFT) & 0xff; /* move CI (8 bits) into lowest byte */
pa |= SBA_PDIR_VALID_BIT; /* set "valid" bit */
*pdir_ptr = cpu_to_le64(pa); /* swap and store into I/O Pdir */
/*
* If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit set
* (bit #61, big endian), we have to flush and sync every time
* IO-PDIR is changed in Ike/Astro.
*/
if (ioc_needs_fdc)
asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
}
/**
* sba_mark_invalid - invalidate one or more IO PDIR entries
* @ioc: IO MMU structure which owns the pdir we are interested in.
* @iova: IO Virtual Address mapped earlier
* @byte_cnt: number of bytes this mapping covers.
*
* Marking the IO PDIR entry(ies) as Invalid and invalidate
* corresponding IO TLB entry. The Ike PCOM (Purge Command Register)
* is to purge stale entries in the IO TLB when unmapping entries.
*
* The PCOM register supports purging of multiple pages, with a minium
* of 1 page and a maximum of 2GB. Hardware requires the address be
* aligned to the size of the range being purged. The size of the range
* must be a power of 2. The "Cool perf optimization" in the
* allocation routine helps keep that true.
*/
static SBA_INLINE void
sba_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
{
u32 iovp = (u32) SBA_IOVP(ioc,iova);
u64 *pdir_ptr = &ioc->pdir_base[PDIR_INDEX(iovp)];
#ifdef ASSERT_PDIR_SANITY
/* Assert first pdir entry is set.
**
** Even though this is a big-endian machine, the entries
** in the iopdir are little endian. That's why we look at
** the byte at +7 instead of at +0.
*/
if (0x80 != (((u8 *) pdir_ptr)[7])) {
sba_dump_pdir_entry(ioc,"sba_mark_invalid()", PDIR_INDEX(iovp));
}
#endif
if (byte_cnt > IOVP_SIZE)
{
#if 0
unsigned long entries_per_cacheline = ioc_needs_fdc ?
L1_CACHE_ALIGN(((unsigned long) pdir_ptr))
- (unsigned long) pdir_ptr;
: 262144;
#endif
/* set "size" field for PCOM */
iovp |= get_order(byte_cnt) + PAGE_SHIFT;
do {
/* clear I/O Pdir entry "valid" bit first */
((u8 *) pdir_ptr)[7] = 0;
if (ioc_needs_fdc) {
asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
#if 0
entries_per_cacheline = L1_CACHE_SHIFT - 3;
#endif
}
pdir_ptr++;
byte_cnt -= IOVP_SIZE;
} while (byte_cnt > IOVP_SIZE);
} else
iovp |= IOVP_SHIFT; /* set "size" field for PCOM */
/*
** clear I/O PDIR entry "valid" bit.
** We have to R/M/W the cacheline regardless how much of the
** pdir entry that we clobber.
** The rest of the entry would be useful for debugging if we
** could dump core on HPMC.
*/
((u8 *) pdir_ptr)[7] = 0;
if (ioc_needs_fdc)
asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
WRITE_REG( SBA_IOVA(ioc, iovp, 0, 0), ioc->ioc_hpa+IOC_PCOM);
}
/**
* sba_dma_supported - PCI driver can query DMA support
* @dev: instance of PCI owned by the driver that's asking
* @mask: number of address bits this PCI device can handle
*
* See Documentation/DMA-API-HOWTO.txt
*/
static int sba_dma_supported( struct device *dev, u64 mask)
{
struct ioc *ioc;
if (dev == NULL) {
printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
BUG();
return(0);
}
/* Documentation/DMA-API-HOWTO.txt tells drivers to try 64-bit
* first, then fall back to 32-bit if that fails.
* We are just "encouraging" 32-bit DMA masks here since we can
* never allow IOMMU bypass unless we add special support for ZX1.
*/
if (mask > ~0U)
return 0;
ioc = GET_IOC(dev);
/*
* check if mask is >= than the current max IO Virt Address
* The max IO Virt address will *always* < 30 bits.
*/
return((int)(mask >= (ioc->ibase - 1 +
(ioc->pdir_size / sizeof(u64) * IOVP_SIZE) )));
}
/**
* sba_map_single - map one buffer and return IOVA for DMA
* @dev: instance of PCI owned by the driver that's asking.
* @addr: driver buffer to map.
* @size: number of bytes to map in driver buffer.
* @direction: R/W or both.
*
* See Documentation/DMA-API-HOWTO.txt
*/
static dma_addr_t
sba_map_single(struct device *dev, void *addr, size_t size,
enum dma_data_direction direction)
{
struct ioc *ioc;
unsigned long flags;
dma_addr_t iovp;
dma_addr_t offset;
u64 *pdir_start;
int pide;
ioc = GET_IOC(dev);
/* save offset bits */
offset = ((dma_addr_t) (long) addr) & ~IOVP_MASK;
/* round up to nearest IOVP_SIZE */
size = (size + offset + ~IOVP_MASK) & IOVP_MASK;
spin_lock_irqsave(&ioc->res_lock, flags);
#ifdef ASSERT_PDIR_SANITY
sba_check_pdir(ioc,"Check before sba_map_single()");
#endif
#ifdef SBA_COLLECT_STATS
ioc->msingle_calls++;
ioc->msingle_pages += size >> IOVP_SHIFT;
#endif
pide = sba_alloc_range(ioc, dev, size);
iovp = (dma_addr_t) pide << IOVP_SHIFT;
DBG_RUN("%s() 0x%p -> 0x%lx\n",
__func__, addr, (long) iovp | offset);
pdir_start = &(ioc->pdir_base[pide]);
while (size > 0) {
sba_io_pdir_entry(pdir_start, KERNEL_SPACE, (unsigned long) addr, 0);
DBG_RUN(" pdir 0x%p %02x%02x%02x%02x%02x%02x%02x%02x\n",
pdir_start,
(u8) (((u8 *) pdir_start)[7]),
(u8) (((u8 *) pdir_start)[6]),
(u8) (((u8 *) pdir_start)[5]),
(u8) (((u8 *) pdir_start)[4]),
(u8) (((u8 *) pdir_start)[3]),
(u8) (((u8 *) pdir_start)[2]),
(u8) (((u8 *) pdir_start)[1]),
(u8) (((u8 *) pdir_start)[0])
);
addr += IOVP_SIZE;
size -= IOVP_SIZE;
pdir_start++;
}
/* force FDC ops in io_pdir_entry() to be visible to IOMMU */
if (ioc_needs_fdc)
asm volatile("sync" : : );
#ifdef ASSERT_PDIR_SANITY
sba_check_pdir(ioc,"Check after sba_map_single()");
#endif
spin_unlock_irqrestore(&ioc->res_lock, flags);
/* form complete address */
return SBA_IOVA(ioc, iovp, offset, DEFAULT_DMA_HINT_REG);
}
/**
* sba_unmap_single - unmap one IOVA and free resources
* @dev: instance of PCI owned by the driver that's asking.
* @iova: IOVA of driver buffer previously mapped.
* @size: number of bytes mapped in driver buffer.
* @direction: R/W or both.
*
* See Documentation/DMA-API-HOWTO.txt
*/
static void
sba_unmap_single(struct device *dev, dma_addr_t iova, size_t size,
enum dma_data_direction direction)
{
struct ioc *ioc;
#if DELAYED_RESOURCE_CNT > 0
struct sba_dma_pair *d;
#endif
unsigned long flags;
dma_addr_t offset;
DBG_RUN("%s() iovp 0x%lx/%x\n", __func__, (long) iova, size);
ioc = GET_IOC(dev);
offset = iova & ~IOVP_MASK;
iova ^= offset; /* clear offset bits */
size += offset;
size = ALIGN(size, IOVP_SIZE);
spin_lock_irqsave(&ioc->res_lock, flags);
#ifdef SBA_COLLECT_STATS
ioc->usingle_calls++;
ioc->usingle_pages += size >> IOVP_SHIFT;
#endif
sba_mark_invalid(ioc, iova, size);
#if DELAYED_RESOURCE_CNT > 0
/* Delaying when we re-use a IO Pdir entry reduces the number
* of MMIO reads needed to flush writes to the PCOM register.
*/
d = &(ioc->saved[ioc->saved_cnt]);
d->iova = iova;
d->size = size;
if (++(ioc->saved_cnt) >= DELAYED_RESOURCE_CNT) {
int cnt = ioc->saved_cnt;
while (cnt--) {
sba_free_range(ioc, d->iova, d->size);
d--;
}
ioc->saved_cnt = 0;
READ_REG(ioc->ioc_hpa+IOC_PCOM); /* flush purges */
}
#else /* DELAYED_RESOURCE_CNT == 0 */
sba_free_range(ioc, iova, size);
/* If fdc's were issued, force fdc's to be visible now */
if (ioc_needs_fdc)
asm volatile("sync" : : );
READ_REG(ioc->ioc_hpa+IOC_PCOM); /* flush purges */
#endif /* DELAYED_RESOURCE_CNT == 0 */
spin_unlock_irqrestore(&ioc->res_lock, flags);
/* XXX REVISIT for 2.5 Linux - need syncdma for zero-copy support.
** For Astro based systems this isn't a big deal WRT performance.
** As long as 2.4 kernels copyin/copyout data from/to userspace,
** we don't need the syncdma. The issue here is I/O MMU cachelines
** are *not* coherent in all cases. May be hwrev dependent.
** Need to investigate more.
asm volatile("syncdma");
*/
}
/**
* sba_alloc_consistent - allocate/map shared mem for DMA
* @hwdev: instance of PCI owned by the driver that's asking.
* @size: number of bytes mapped in driver buffer.
* @dma_handle: IOVA of new buffer.
*
* See Documentation/DMA-API-HOWTO.txt
*/
static void *sba_alloc_consistent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
void *ret;
if (!hwdev) {
/* only support PCI */
*dma_handle = 0;
return NULL;
}
ret = (void *) __get_free_pages(gfp, get_order(size));
if (ret) {
memset(ret, 0, size);
*dma_handle = sba_map_single(hwdev, ret, size, 0);
}
return ret;
}
/**
* sba_free_consistent - free/unmap shared mem for DMA
* @hwdev: instance of PCI owned by the driver that's asking.
* @size: number of bytes mapped in driver buffer.
* @vaddr: virtual address IOVA of "consistent" buffer.
* @dma_handler: IO virtual address of "consistent" buffer.
*
* See Documentation/DMA-API-HOWTO.txt
*/
static void
sba_free_consistent(struct device *hwdev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
sba_unmap_single(hwdev, dma_handle, size, 0);
free_pages((unsigned long) vaddr, get_order(size));
}
/*
** Since 0 is a valid pdir_base index value, can't use that
** to determine if a value is valid or not. Use a flag to indicate
** the SG list entry contains a valid pdir index.
*/
#define PIDE_FLAG 0x80000000UL
#ifdef SBA_COLLECT_STATS
#define IOMMU_MAP_STATS
#endif
#include "iommu-helpers.h"
#ifdef DEBUG_LARGE_SG_ENTRIES
int dump_run_sg = 0;
#endif
/**
* sba_map_sg - map Scatter/Gather list
* @dev: instance of PCI owned by the driver that's asking.
* @sglist: array of buffer/length pairs
* @nents: number of entries in list
* @direction: R/W or both.
*
* See Documentation/DMA-API-HOWTO.txt
*/
static int
sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
enum dma_data_direction direction)
{
struct ioc *ioc;
int coalesced, filled = 0;
unsigned long flags;
DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
ioc = GET_IOC(dev);
/* Fast path single entry scatterlists. */
if (nents == 1) {
sg_dma_address(sglist) = sba_map_single(dev, sg_virt(sglist),
sglist->length, direction);
sg_dma_len(sglist) = sglist->length;
return 1;
}
spin_lock_irqsave(&ioc->res_lock, flags);
#ifdef ASSERT_PDIR_SANITY
if (sba_check_pdir(ioc,"Check before sba_map_sg()"))
{
sba_dump_sg(ioc, sglist, nents);
panic("Check before sba_map_sg()");
}
#endif
#ifdef SBA_COLLECT_STATS
ioc->msg_calls++;
#endif
/*
** First coalesce the chunks and allocate I/O pdir space
**
** If this is one DMA stream, we can properly map using the
** correct virtual address associated with each DMA page.
** w/o this association, we wouldn't have coherent DMA!
** Access to the virtual address is what forces a two pass algorithm.
*/
coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, sba_alloc_range);
/*
** Program the I/O Pdir
**
** map the virtual addresses to the I/O Pdir
** o dma_address will contain the pdir index
** o dma_len will contain the number of bytes to map
** o address contains the virtual address.
*/
filled = iommu_fill_pdir(ioc, sglist, nents, 0, sba_io_pdir_entry);
/* force FDC ops in io_pdir_entry() to be visible to IOMMU */
if (ioc_needs_fdc)
asm volatile("sync" : : );
#ifdef ASSERT_PDIR_SANITY
if (sba_check_pdir(ioc,"Check after sba_map_sg()"))
{
sba_dump_sg(ioc, sglist, nents);
panic("Check after sba_map_sg()\n");
}
#endif
spin_unlock_irqrestore(&ioc->res_lock, flags);
DBG_RUN_SG("%s() DONE %d mappings\n", __func__, filled);
return filled;
}
/**
* sba_unmap_sg - unmap Scatter/Gather list
* @dev: instance of PCI owned by the driver that's asking.
* @sglist: array of buffer/length pairs
* @nents: number of entries in list
* @direction: R/W or both.
*
* See Documentation/DMA-API-HOWTO.txt
*/
static void
sba_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
enum dma_data_direction direction)
{
struct ioc *ioc;
#ifdef ASSERT_PDIR_SANITY
unsigned long flags;
#endif
DBG_RUN_SG("%s() START %d entries, %p,%x\n",
__func__, nents, sg_virt(sglist), sglist->length);
ioc = GET_IOC(dev);
#ifdef SBA_COLLECT_STATS
ioc->usg_calls++;
#endif
#ifdef ASSERT_PDIR_SANITY
spin_lock_irqsave(&ioc->res_lock, flags);
sba_check_pdir(ioc,"Check before sba_unmap_sg()");
spin_unlock_irqrestore(&ioc->res_lock, flags);
#endif
while (sg_dma_len(sglist) && nents--) {
sba_unmap_single(dev, sg_dma_address(sglist), sg_dma_len(sglist), direction);
#ifdef SBA_COLLECT_STATS
ioc->usg_pages += ((sg_dma_address(sglist) & ~IOVP_MASK) + sg_dma_len(sglist) + IOVP_SIZE - 1) >> PAGE_SHIFT;
ioc->usingle_calls--; /* kluge since call is unmap_sg() */
#endif
++sglist;
}
DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents);
#ifdef ASSERT_PDIR_SANITY
spin_lock_irqsave(&ioc->res_lock, flags);
sba_check_pdir(ioc,"Check after sba_unmap_sg()");
spin_unlock_irqrestore(&ioc->res_lock, flags);
#endif
}
static struct hppa_dma_ops sba_ops = {
.dma_supported = sba_dma_supported,
.alloc_consistent = sba_alloc_consistent,
.alloc_noncoherent = sba_alloc_consistent,
.free_consistent = sba_free_consistent,
.map_single = sba_map_single,
.unmap_single = sba_unmap_single,
.map_sg = sba_map_sg,
.unmap_sg = sba_unmap_sg,
.dma_sync_single_for_cpu = NULL,
.dma_sync_single_for_device = NULL,
.dma_sync_sg_for_cpu = NULL,
.dma_sync_sg_for_device = NULL,
};
/**************************************************************************
**
** SBA PAT PDC support
**
** o call pdc_pat_cell_module()
** o store ranges in PCI "resource" structures
**
**************************************************************************/
static void
sba_get_pat_resources(struct sba_device *sba_dev)
{
#if 0
/*
** TODO/REVISIT/FIXME: support for directed ranges requires calls to
** PAT PDC to program the SBA/LBA directed range registers...this
** burden may fall on the LBA code since it directly supports the
** PCI subsystem. It's not clear yet. - ggg
*/
PAT_MOD(mod)->mod_info.mod_pages = PAT_GET_MOD_PAGES(temp);
FIXME : ???
PAT_MOD(mod)->mod_info.dvi = PAT_GET_DVI(temp);
Tells where the dvi bits are located in the address.
PAT_MOD(mod)->mod_info.ioc = PAT_GET_IOC(temp);
FIXME : ???
#endif
}
/**************************************************************
*
* Initialization and claim
*
***************************************************************/
#define PIRANHA_ADDR_MASK 0x00160000UL /* bit 17,18,20 */
#define PIRANHA_ADDR_VAL 0x00060000UL /* bit 17,18 on */
static void *
sba_alloc_pdir(unsigned int pdir_size)
{
unsigned long pdir_base;
unsigned long pdir_order = get_order(pdir_size);
pdir_base = __get_free_pages(GFP_KERNEL, pdir_order);
if (NULL == (void *) pdir_base) {
panic("%s() could not allocate I/O Page Table\n",
__func__);
}
/* If this is not PA8700 (PCX-W2)
** OR newer than ver 2.2
** OR in a system that doesn't need VINDEX bits from SBA,
**
** then we aren't exposed to the HW bug.
*/
if ( ((boot_cpu_data.pdc.cpuid >> 5) & 0x7f) != 0x13
|| (boot_cpu_data.pdc.versions > 0x202)
|| (boot_cpu_data.pdc.capabilities & 0x08L) )
return (void *) pdir_base;
/*
* PA8700 (PCX-W2, aka piranha) silent data corruption fix
*
* An interaction between PA8700 CPU (Ver 2.2 or older) and
* Ike/Astro can cause silent data corruption. This is only
* a problem if the I/O PDIR is located in memory such that
* (little-endian) bits 17 and 18 are on and bit 20 is off.
*
* Since the max IO Pdir size is 2MB, by cleverly allocating the
* right physical address, we can either avoid (IOPDIR <= 1MB)
* or minimize (2MB IO Pdir) the problem if we restrict the
* IO Pdir to a maximum size of 2MB-128K (1902K).
*
* Because we always allocate 2^N sized IO pdirs, either of the
* "bad" regions will be the last 128K if at all. That's easy
* to test for.
*
*/
if (pdir_order <= (19-12)) {
if (((virt_to_phys(pdir_base)+pdir_size-1) & PIRANHA_ADDR_MASK) == PIRANHA_ADDR_VAL) {
/* allocate a new one on 512k alignment */
unsigned long new_pdir = __get_free_pages(GFP_KERNEL, (19-12));
/* release original */
free_pages(pdir_base, pdir_order);
pdir_base = new_pdir;
/* release excess */
while (pdir_order < (19-12)) {
new_pdir += pdir_size;
free_pages(new_pdir, pdir_order);
pdir_order +=1;
pdir_size <<=1;
}
}
} else {
/*
** 1MB or 2MB Pdir
** Needs to be aligned on an "odd" 1MB boundary.
*/
unsigned long new_pdir = __get_free_pages(GFP_KERNEL, pdir_order+1); /* 2 or 4MB */
/* release original */
free_pages( pdir_base, pdir_order);
/* release first 1MB */
free_pages(new_pdir, 20-12);
pdir_base = new_pdir + 1024*1024;
if (pdir_order > (20-12)) {
/*
** 2MB Pdir.
**
** Flag tells init_bitmap() to mark bad 128k as used
** and to reduce the size by 128k.
*/
piranha_bad_128k = 1;
new_pdir += 3*1024*1024;
/* release last 1MB */
free_pages(new_pdir, 20-12);
/* release unusable 128KB */
free_pages(new_pdir - 128*1024 , 17-12);
pdir_size -= 128*1024;
}
}
memset((void *) pdir_base, 0, pdir_size);
return (void *) pdir_base;
}
struct ibase_data_struct {
struct ioc *ioc;
int ioc_num;
};
static int setup_ibase_imask_callback(struct device *dev, void *data)
{
/* lba_set_iregs() is in drivers/parisc/lba_pci.c */
extern void lba_set_iregs(struct parisc_device *, u32, u32);
struct parisc_device *lba = to_parisc_device(dev);
struct ibase_data_struct *ibd = data;
int rope_num = (lba->hpa.start >> 13) & 0xf;
if (rope_num >> 3 == ibd->ioc_num)
lba_set_iregs(lba, ibd->ioc->ibase, ibd->ioc->imask);
return 0;
}
/* setup Mercury or Elroy IBASE/IMASK registers. */
static void
setup_ibase_imask(struct parisc_device *sba, struct ioc *ioc, int ioc_num)
{
struct ibase_data_struct ibase_data = {
.ioc = ioc,
.ioc_num = ioc_num,
};
device_for_each_child(&sba->dev, &ibase_data,
setup_ibase_imask_callback);
}
#ifdef SBA_AGP_SUPPORT
static int
sba_ioc_find_quicksilver(struct device *dev, void *data)
{
int *agp_found = data;
struct parisc_device *lba = to_parisc_device(dev);
if (IS_QUICKSILVER(lba))
*agp_found = 1;
return 0;
}
#endif
static void
sba_ioc_init_pluto(struct parisc_device *sba, struct ioc *ioc, int ioc_num)
{
u32 iova_space_mask;
u32 iova_space_size;
int iov_order, tcnfg;
#ifdef SBA_AGP_SUPPORT
int agp_found = 0;
#endif
/*
** Firmware programs the base and size of a "safe IOVA space"
** (one that doesn't overlap memory or LMMIO space) in the
** IBASE and IMASK registers.
*/
ioc->ibase = READ_REG(ioc->ioc_hpa + IOC_IBASE);
iova_space_size = ~(READ_REG(ioc->ioc_hpa + IOC_IMASK) & 0xFFFFFFFFUL) + 1;
if ((ioc->ibase < 0xfed00000UL) && ((ioc->ibase + iova_space_size) > 0xfee00000UL)) {
printk("WARNING: IOV space overlaps local config and interrupt message, truncating\n");
iova_space_size /= 2;
}
/*
** iov_order is always based on a 1GB IOVA space since we want to
** turn on the other half for AGP GART.
*/
iov_order = get_order(iova_space_size >> (IOVP_SHIFT - PAGE_SHIFT));
ioc->pdir_size = (iova_space_size / IOVP_SIZE) * sizeof(u64);
DBG_INIT("%s() hpa 0x%p IOV %dMB (%d bits)\n",
__func__, ioc->ioc_hpa, iova_space_size >> 20,
iov_order + PAGE_SHIFT);
ioc->pdir_base = (void *) __get_free_pages(GFP_KERNEL,
get_order(ioc->pdir_size));
if (!ioc->pdir_base)
panic("Couldn't allocate I/O Page Table\n");
memset(ioc->pdir_base, 0, ioc->pdir_size);
DBG_INIT("%s() pdir %p size %x\n",
__func__, ioc->pdir_base, ioc->pdir_size);
#ifdef SBA_HINT_SUPPORT
ioc->hint_shift_pdir = iov_order + PAGE_SHIFT;
ioc->hint_mask_pdir = ~(0x3 << (iov_order + PAGE_SHIFT));
DBG_INIT(" hint_shift_pdir %x hint_mask_pdir %lx\n",
ioc->hint_shift_pdir, ioc->hint_mask_pdir);
#endif
WARN_ON((((unsigned long) ioc->pdir_base) & PAGE_MASK) != (unsigned long) ioc->pdir_base);
WRITE_REG(virt_to_phys(ioc->pdir_base), ioc->ioc_hpa + IOC_PDIR_BASE);
/* build IMASK for IOC and Elroy */
iova_space_mask = 0xffffffff;
iova_space_mask <<= (iov_order + PAGE_SHIFT);
ioc->imask = iova_space_mask;
#ifdef ZX1_SUPPORT
ioc->iovp_mask = ~(iova_space_mask + PAGE_SIZE - 1);
#endif
sba_dump_tlb(ioc->ioc_hpa);
setup_ibase_imask(sba, ioc, ioc_num);
WRITE_REG(ioc->imask, ioc->ioc_hpa + IOC_IMASK);
#ifdef CONFIG_64BIT
/*
** Setting the upper bits makes checking for bypass addresses
** a little faster later on.
*/
ioc->imask |= 0xFFFFFFFF00000000UL;
#endif
/* Set I/O PDIR Page size to system page size */
switch (PAGE_SHIFT) {
case 12: tcnfg = 0; break; /* 4K */
case 13: tcnfg = 1; break; /* 8K */
case 14: tcnfg = 2; break; /* 16K */
case 16: tcnfg = 3; break; /* 64K */
default:
panic(__FILE__ "Unsupported system page size %d",
1 << PAGE_SHIFT);
break;
}
WRITE_REG(tcnfg, ioc->ioc_hpa + IOC_TCNFG);
/*
** Program the IOC's ibase and enable IOVA translation
** Bit zero == enable bit.
*/
WRITE_REG(ioc->ibase | 1, ioc->ioc_hpa + IOC_IBASE);
/*
** Clear I/O TLB of any possible entries.
** (Yes. This is a bit paranoid...but so what)
*/
WRITE_REG(ioc->ibase | 31, ioc->ioc_hpa + IOC_PCOM);
#ifdef SBA_AGP_SUPPORT
/*
** If an AGP device is present, only use half of the IOV space
** for PCI DMA. Unfortunately we can't know ahead of time
** whether GART support will actually be used, for now we
** can just key on any AGP device found in the system.
** We program the next pdir index after we stop w/ a key for
** the GART code to handshake on.
*/
device_for_each_child(&sba->dev, &agp_found, sba_ioc_find_quicksilver);
if (agp_found && sba_reserve_agpgart) {
printk(KERN_INFO "%s: reserving %dMb of IOVA space for agpgart\n",
__func__, (iova_space_size/2) >> 20);
ioc->pdir_size /= 2;
ioc->pdir_base[PDIR_INDEX(iova_space_size/2)] = SBA_AGPGART_COOKIE;
}
#endif /*SBA_AGP_SUPPORT*/
}
static void
sba_ioc_init(struct parisc_device *sba, struct ioc *ioc, int ioc_num)
{
u32 iova_space_size, iova_space_mask;
unsigned int pdir_size, iov_order, tcnfg;
/*
** Determine IOVA Space size from memory size.
**
** Ideally, PCI drivers would register the maximum number
** of DMA they can have outstanding for each device they
** own. Next best thing would be to guess how much DMA
** can be outstanding based on PCI Class/sub-class. Both
** methods still require some "extra" to support PCI
** Hot-Plug/Removal of PCI cards. (aka PCI OLARD).
**
** While we have 32-bits "IOVA" space, top two 2 bits are used
** for DMA hints - ergo only 30 bits max.
*/
iova_space_size = (u32) (totalram_pages/global_ioc_cnt);
/* limit IOVA space size to 1MB-1GB */
if (iova_space_size < (1 << (20 - PAGE_SHIFT))) {
iova_space_size = 1 << (20 - PAGE_SHIFT);
}
else if (iova_space_size > (1 << (30 - PAGE_SHIFT))) {
iova_space_size = 1 << (30 - PAGE_SHIFT);
}
/*
** iova space must be log2() in size.
** thus, pdir/res_map will also be log2().
** PIRANHA BUG: Exception is when IO Pdir is 2MB (gets reduced)
*/
iov_order = get_order(iova_space_size << PAGE_SHIFT);
/* iova_space_size is now bytes, not pages */
iova_space_size = 1 << (iov_order + PAGE_SHIFT);
ioc->pdir_size = pdir_size = (iova_space_size/IOVP_SIZE) * sizeof(u64);
DBG_INIT("%s() hpa 0x%lx mem %ldMB IOV %dMB (%d bits)\n",
__func__,
ioc->ioc_hpa,
(unsigned long) totalram_pages >> (20 - PAGE_SHIFT),
iova_space_size>>20,
iov_order + PAGE_SHIFT);
ioc->pdir_base = sba_alloc_pdir(pdir_size);
DBG_INIT("%s() pdir %p size %x\n",
__func__, ioc->pdir_base, pdir_size);
#ifdef SBA_HINT_SUPPORT
/* FIXME : DMA HINTs not used */
ioc->hint_shift_pdir = iov_order + PAGE_SHIFT;
ioc->hint_mask_pdir = ~(0x3 << (iov_order + PAGE_SHIFT));
DBG_INIT(" hint_shift_pdir %x hint_mask_pdir %lx\n",
ioc->hint_shift_pdir, ioc->hint_mask_pdir);
#endif
WRITE_REG64(virt_to_phys(ioc->pdir_base), ioc->ioc_hpa + IOC_PDIR_BASE);
/* build IMASK for IOC and Elroy */
iova_space_mask = 0xffffffff;
iova_space_mask <<= (iov_order + PAGE_SHIFT);
/*
** On C3000 w/512MB mem, HP-UX 10.20 reports:
** ibase=0, imask=0xFE000000, size=0x2000000.
*/
ioc->ibase = 0;
ioc->imask = iova_space_mask; /* save it */
#ifdef ZX1_SUPPORT
ioc->iovp_mask = ~(iova_space_mask + PAGE_SIZE - 1);
#endif
DBG_INIT("%s() IOV base 0x%lx mask 0x%0lx\n",
__func__, ioc->ibase, ioc->imask);
/*
** FIXME: Hint registers are programmed with default hint
** values during boot, so hints should be sane even if we
** can't reprogram them the way drivers want.
*/
setup_ibase_imask(sba, ioc, ioc_num);
/*
** Program the IOC's ibase and enable IOVA translation
*/
WRITE_REG(ioc->ibase | 1, ioc->ioc_hpa+IOC_IBASE);
WRITE_REG(ioc->imask, ioc->ioc_hpa+IOC_IMASK);
/* Set I/O PDIR Page size to system page size */
switch (PAGE_SHIFT) {
case 12: tcnfg = 0; break; /* 4K */
case 13: tcnfg = 1; break; /* 8K */
case 14: tcnfg = 2; break; /* 16K */
case 16: tcnfg = 3; break; /* 64K */
default:
panic(__FILE__ "Unsupported system page size %d",
1 << PAGE_SHIFT);
break;
}
/* Set I/O PDIR Page size to PAGE_SIZE (4k/16k/...) */
WRITE_REG(tcnfg, ioc->ioc_hpa+IOC_TCNFG);
/*
** Clear I/O TLB of any possible entries.
** (Yes. This is a bit paranoid...but so what)
*/
WRITE_REG(0 | 31, ioc->ioc_hpa+IOC_PCOM);
ioc->ibase = 0; /* used by SBA_IOVA and related macros */
DBG_INIT("%s() DONE\n", __func__);
}
/**************************************************************************
**
** SBA initialization code (HW and SW)
**
** o identify SBA chip itself
** o initialize SBA chip modes (HardFail)
** o initialize SBA chip modes (HardFail)
** o FIXME: initialize DMA hints for reasonable defaults
**
**************************************************************************/
static void __iomem *ioc_remap(struct sba_device *sba_dev, unsigned int offset)
{
return ioremap_nocache(sba_dev->dev->hpa.start + offset, SBA_FUNC_SIZE);
}
static void sba_hw_init(struct sba_device *sba_dev)
{
int i;
int num_ioc;
u64 ioc_ctl;
if (!is_pdc_pat()) {
/* Shutdown the USB controller on Astro-based workstations.
** Once we reprogram the IOMMU, the next DMA performed by
** USB will HPMC the box. USB is only enabled if a
** keyboard is present and found.
**
** With serial console, j6k v5.0 firmware says:
** mem_kbd hpa 0xfee003f8 sba 0x0 pad 0x0 cl_class 0x7
**
** FIXME: Using GFX+USB console at power up but direct
** linux to serial console is still broken.
** USB could generate DMA so we must reset USB.
** The proper sequence would be:
** o block console output
** o reset USB device
** o reprogram serial port
** o unblock console output
*/
if (PAGE0->mem_kbd.cl_class == CL_KEYBD) {
pdc_io_reset_devices();
}
}
#if 0
printk("sba_hw_init(): mem_boot 0x%x 0x%x 0x%x 0x%x\n", PAGE0->mem_boot.hpa,
PAGE0->mem_boot.spa, PAGE0->mem_boot.pad, PAGE0->mem_boot.cl_class);
/*
** Need to deal with DMA from LAN.
** Maybe use page zero boot device as a handle to talk
** to PDC about which device to shutdown.
**
** Netbooting, j6k v5.0 firmware says:
** mem_boot hpa 0xf4008000 sba 0x0 pad 0x0 cl_class 0x1002
** ARGH! invalid class.
*/
if ((PAGE0->mem_boot.cl_class != CL_RANDOM)
&& (PAGE0->mem_boot.cl_class != CL_SEQU)) {
pdc_io_reset();
}
#endif
if (!IS_PLUTO(sba_dev->dev)) {
ioc_ctl = READ_REG(sba_dev->sba_hpa+IOC_CTRL);
DBG_INIT("%s() hpa 0x%lx ioc_ctl 0x%Lx ->",
__func__, sba_dev->sba_hpa, ioc_ctl);
ioc_ctl &= ~(IOC_CTRL_RM | IOC_CTRL_NC | IOC_CTRL_CE);
ioc_ctl |= IOC_CTRL_DD | IOC_CTRL_D4 | IOC_CTRL_TC;
/* j6700 v1.6 firmware sets 0x294f */
/* A500 firmware sets 0x4d */
WRITE_REG(ioc_ctl, sba_dev->sba_hpa+IOC_CTRL);
#ifdef DEBUG_SBA_INIT
ioc_ctl = READ_REG64(sba_dev->sba_hpa+IOC_CTRL);
DBG_INIT(" 0x%Lx\n", ioc_ctl);
#endif
} /* if !PLUTO */
if (IS_ASTRO(sba_dev->dev)) {
int err;
sba_dev->ioc[0].ioc_hpa = ioc_remap(sba_dev, ASTRO_IOC_OFFSET);
num_ioc = 1;
sba_dev->chip_resv.name = "Astro Intr Ack";
sba_dev->chip_resv.start = PCI_F_EXTEND | 0xfef00000UL;
sba_dev->chip_resv.end = PCI_F_EXTEND | (0xff000000UL - 1) ;
err = request_resource(&iomem_resource, &(sba_dev->chip_resv));
BUG_ON(err < 0);
} else if (IS_PLUTO(sba_dev->dev)) {
int err;
sba_dev->ioc[0].ioc_hpa = ioc_remap(sba_dev, PLUTO_IOC_OFFSET);
num_ioc = 1;
sba_dev->chip_resv.name = "Pluto Intr/PIOP/VGA";
sba_dev->chip_resv.start = PCI_F_EXTEND | 0xfee00000UL;
sba_dev->chip_resv.end = PCI_F_EXTEND | (0xff200000UL - 1);
err = request_resource(&iomem_resource, &(sba_dev->chip_resv));
WARN_ON(err < 0);
sba_dev->iommu_resv.name = "IOVA Space";
sba_dev->iommu_resv.start = 0x40000000UL;
sba_dev->iommu_resv.end = 0x50000000UL - 1;
err = request_resource(&iomem_resource, &(sba_dev->iommu_resv));
WARN_ON(err < 0);
} else {
/* IKE, REO */
sba_dev->ioc[0].ioc_hpa = ioc_remap(sba_dev, IKE_IOC_OFFSET(0));
sba_dev->ioc[1].ioc_hpa = ioc_remap(sba_dev, IKE_IOC_OFFSET(1));
num_ioc = 2;
/* TODO - LOOKUP Ike/Stretch chipset mem map */
}
/* XXX: What about Reo Grande? */
sba_dev->num_ioc = num_ioc;
for (i = 0; i < num_ioc; i++) {
void __iomem *ioc_hpa = sba_dev->ioc[i].ioc_hpa;
unsigned int j;
for (j=0; j < sizeof(u64) * ROPES_PER_IOC; j+=sizeof(u64)) {
/*
* Clear ROPE(N)_CONFIG AO bit.
* Disables "NT Ordering" (~= !"Relaxed Ordering")
* Overrides bit 1 in DMA Hint Sets.
* Improves netperf UDP_STREAM by ~10% for bcm5701.
*/
if (IS_PLUTO(sba_dev->dev)) {
void __iomem *rope_cfg;
unsigned long cfg_val;
rope_cfg = ioc_hpa + IOC_ROPE0_CFG + j;
cfg_val = READ_REG(rope_cfg);
cfg_val &= ~IOC_ROPE_AO;
WRITE_REG(cfg_val, rope_cfg);
}
/*
** Make sure the box crashes on rope errors.
*/
WRITE_REG(HF_ENABLE, ioc_hpa + ROPE0_CTL + j);
}
/* flush out the last writes */
READ_REG(sba_dev->ioc[i].ioc_hpa + ROPE7_CTL);
DBG_INIT(" ioc[%d] ROPE_CFG 0x%Lx ROPE_DBG 0x%Lx\n",
i,
READ_REG(sba_dev->ioc[i].ioc_hpa + 0x40),
READ_REG(sba_dev->ioc[i].ioc_hpa + 0x50)
);
DBG_INIT(" STATUS_CONTROL 0x%Lx FLUSH_CTRL 0x%Lx\n",
READ_REG(sba_dev->ioc[i].ioc_hpa + 0x108),
READ_REG(sba_dev->ioc[i].ioc_hpa + 0x400)
);
if (IS_PLUTO(sba_dev->dev)) {
sba_ioc_init_pluto(sba_dev->dev, &(sba_dev->ioc[i]), i);
} else {
sba_ioc_init(sba_dev->dev, &(sba_dev->ioc[i]), i);
}
}
}
static void
sba_common_init(struct sba_device *sba_dev)
{
int i;
/* add this one to the head of the list (order doesn't matter)
** This will be useful for debugging - especially if we get coredumps
*/
sba_dev->next = sba_list;
sba_list = sba_dev;
for(i=0; i< sba_dev->num_ioc; i++) {
int res_size;
#ifdef DEBUG_DMB_TRAP
extern void iterate_pages(unsigned long , unsigned long ,
void (*)(pte_t * , unsigned long),
unsigned long );
void set_data_memory_break(pte_t * , unsigned long);
#endif
/* resource map size dictated by pdir_size */
res_size = sba_dev->ioc[i].pdir_size/sizeof(u64); /* entries */
/* Second part of PIRANHA BUG */
if (piranha_bad_128k) {
res_size -= (128*1024)/sizeof(u64);
}
res_size >>= 3; /* convert bit count to byte count */
DBG_INIT("%s() res_size 0x%x\n",
__func__, res_size);
sba_dev->ioc[i].res_size = res_size;
sba_dev->ioc[i].res_map = (char *) __get_free_pages(GFP_KERNEL, get_order(res_size));
#ifdef DEBUG_DMB_TRAP
iterate_pages( sba_dev->ioc[i].res_map, res_size,
set_data_memory_break, 0);
#endif
if (NULL == sba_dev->ioc[i].res_map)
{
panic("%s:%s() could not allocate resource map\n",
__FILE__, __func__ );
}
memset(sba_dev->ioc[i].res_map, 0, res_size);
/* next available IOVP - circular search */
sba_dev->ioc[i].res_hint = (unsigned long *)
&(sba_dev->ioc[i].res_map[L1_CACHE_BYTES]);
#ifdef ASSERT_PDIR_SANITY
/* Mark first bit busy - ie no IOVA 0 */
sba_dev->ioc[i].res_map[0] = 0x80;
sba_dev->ioc[i].pdir_base[0] = 0xeeffc0addbba0080ULL;
#endif
/* Third (and last) part of PIRANHA BUG */
if (piranha_bad_128k) {
/* region from +1408K to +1536 is un-usable. */
int idx_start = (1408*1024/sizeof(u64)) >> 3;
int idx_end = (1536*1024/sizeof(u64)) >> 3;
long *p_start = (long *) &(sba_dev->ioc[i].res_map[idx_start]);
long *p_end = (long *) &(sba_dev->ioc[i].res_map[idx_end]);
/* mark that part of the io pdir busy */
while (p_start < p_end)
*p_start++ = -1;
}
#ifdef DEBUG_DMB_TRAP
iterate_pages( sba_dev->ioc[i].res_map, res_size,
set_data_memory_break, 0);
iterate_pages( sba_dev->ioc[i].pdir_base, sba_dev->ioc[i].pdir_size,
set_data_memory_break, 0);
#endif
DBG_INIT("%s() %d res_map %x %p\n",
__func__, i, res_size, sba_dev->ioc[i].res_map);
}
spin_lock_init(&sba_dev->sba_lock);
ioc_needs_fdc = boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC;
#ifdef DEBUG_SBA_INIT
/*
* If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit set
* (bit #61, big endian), we have to flush and sync every time
* IO-PDIR is changed in Ike/Astro.
*/
if (ioc_needs_fdc) {
printk(KERN_INFO MODULE_NAME " FDC/SYNC required.\n");
} else {
printk(KERN_INFO MODULE_NAME " IOC has cache coherent PDIR.\n");
}
#endif
}
#ifdef CONFIG_PROC_FS
static int sba_proc_info(struct seq_file *m, void *p)
{
struct sba_device *sba_dev = sba_list;
struct ioc *ioc = &sba_dev->ioc[0]; /* FIXME: Multi-IOC support! */
int total_pages = (int) (ioc->res_size << 3); /* 8 bits per byte */
#ifdef SBA_COLLECT_STATS
unsigned long avg = 0, min, max;
#endif
int i;
seq_printf(m, "%s rev %d.%d\n",
sba_dev->name,
(sba_dev->hw_rev & 0x7) + 1,
(sba_dev->hw_rev & 0x18) >> 3);
seq_printf(m, "IO PDIR size : %d bytes (%d entries)\n",
(int)((ioc->res_size << 3) * sizeof(u64)), /* 8 bits/byte */
total_pages);
seq_printf(m, "Resource bitmap : %d bytes (%d pages)\n",
ioc->res_size, ioc->res_size << 3); /* 8 bits per byte */
seq_printf(m, "LMMIO_BASE/MASK/ROUTE %08x %08x %08x\n",
READ_REG32(sba_dev->sba_hpa + LMMIO_DIST_BASE),
READ_REG32(sba_dev->sba_hpa + LMMIO_DIST_MASK),
READ_REG32(sba_dev->sba_hpa + LMMIO_DIST_ROUTE));
for (i=0; i<4; i++)
seq_printf(m, "DIR%d_BASE/MASK/ROUTE %08x %08x %08x\n",
i,
READ_REG32(sba_dev->sba_hpa + LMMIO_DIRECT0_BASE + i*0x18),
READ_REG32(sba_dev->sba_hpa + LMMIO_DIRECT0_MASK + i*0x18),
READ_REG32(sba_dev->sba_hpa + LMMIO_DIRECT0_ROUTE + i*0x18));
#ifdef SBA_COLLECT_STATS
seq_printf(m, "IO PDIR entries : %ld free %ld used (%d%%)\n",
total_pages - ioc->used_pages, ioc->used_pages,
(int)(ioc->used_pages * 100 / total_pages));
min = max = ioc->avg_search[0];
for (i = 0; i < SBA_SEARCH_SAMPLE; i++) {
avg += ioc->avg_search[i];
if (ioc->avg_search[i] > max) max = ioc->avg_search[i];
if (ioc->avg_search[i] < min) min = ioc->avg_search[i];
}
avg /= SBA_SEARCH_SAMPLE;
seq_printf(m, " Bitmap search : %ld/%ld/%ld (min/avg/max CPU Cycles)\n",
min, avg, max);
seq_printf(m, "pci_map_single(): %12ld calls %12ld pages (avg %d/1000)\n",
ioc->msingle_calls, ioc->msingle_pages,
(int)((ioc->msingle_pages * 1000)/ioc->msingle_calls));
/* KLUGE - unmap_sg calls unmap_single for each mapped page */
min = ioc->usingle_calls;
max = ioc->usingle_pages - ioc->usg_pages;
seq_printf(m, "pci_unmap_single: %12ld calls %12ld pages (avg %d/1000)\n",
min, max, (int)((max * 1000)/min));
seq_printf(m, "pci_map_sg() : %12ld calls %12ld pages (avg %d/1000)\n",
ioc->msg_calls, ioc->msg_pages,
(int)((ioc->msg_pages * 1000)/ioc->msg_calls));
seq_printf(m, "pci_unmap_sg() : %12ld calls %12ld pages (avg %d/1000)\n",
ioc->usg_calls, ioc->usg_pages,
(int)((ioc->usg_pages * 1000)/ioc->usg_calls));
#endif
return 0;
}
static int
sba_proc_open(struct inode *i, struct file *f)
{
return single_open(f, &sba_proc_info, NULL);
}
static const struct file_operations sba_proc_fops = {
.owner = THIS_MODULE,
.open = sba_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int
sba_proc_bitmap_info(struct seq_file *m, void *p)
{
struct sba_device *sba_dev = sba_list;
struct ioc *ioc = &sba_dev->ioc[0]; /* FIXME: Multi-IOC support! */
seq_hex_dump(m, " ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
ioc->res_size, false);
seq_putc(m, '\n');
return 0;
}
static int
sba_proc_bitmap_open(struct inode *i, struct file *f)
{
return single_open(f, &sba_proc_bitmap_info, NULL);
}
static const struct file_operations sba_proc_bitmap_fops = {
.owner = THIS_MODULE,
.open = sba_proc_bitmap_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif /* CONFIG_PROC_FS */
static struct parisc_device_id sba_tbl[] = {
{ HPHW_IOA, HVERSION_REV_ANY_ID, ASTRO_RUNWAY_PORT, 0xb },
{ HPHW_BCPORT, HVERSION_REV_ANY_ID, IKE_MERCED_PORT, 0xc },
{ HPHW_BCPORT, HVERSION_REV_ANY_ID, REO_MERCED_PORT, 0xc },
{ HPHW_BCPORT, HVERSION_REV_ANY_ID, REOG_MERCED_PORT, 0xc },
{ HPHW_IOA, HVERSION_REV_ANY_ID, PLUTO_MCKINLEY_PORT, 0xc },
{ 0, }
};
static int sba_driver_callback(struct parisc_device *);
static struct parisc_driver sba_driver = {
.name = MODULE_NAME,
.id_table = sba_tbl,
.probe = sba_driver_callback,
};
/*
** Determine if sba should claim this chip (return 0) or not (return 1).
** If so, initialize the chip and tell other partners in crime they
** have work to do.
*/
static int sba_driver_callback(struct parisc_device *dev)
{
struct sba_device *sba_dev;
u32 func_class;
int i;
char *version;
void __iomem *sba_addr = ioremap_nocache(dev->hpa.start, SBA_FUNC_SIZE);
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *root;
#endif
sba_dump_ranges(sba_addr);
/* Read HW Rev First */
func_class = READ_REG(sba_addr + SBA_FCLASS);
if (IS_ASTRO(dev)) {
unsigned long fclass;
static char astro_rev[]="Astro ?.?";
/* Astro is broken...Read HW Rev First */
fclass = READ_REG(sba_addr);
astro_rev[6] = '1' + (char) (fclass & 0x7);
astro_rev[8] = '0' + (char) ((fclass & 0x18) >> 3);
version = astro_rev;
} else if (IS_IKE(dev)) {
static char ike_rev[] = "Ike rev ?";
ike_rev[8] = '0' + (char) (func_class & 0xff);
version = ike_rev;
} else if (IS_PLUTO(dev)) {
static char pluto_rev[]="Pluto ?.?";
pluto_rev[6] = '0' + (char) ((func_class & 0xf0) >> 4);
pluto_rev[8] = '0' + (char) (func_class & 0x0f);
version = pluto_rev;
} else {
static char reo_rev[] = "REO rev ?";
reo_rev[8] = '0' + (char) (func_class & 0xff);
version = reo_rev;
}
if (!global_ioc_cnt) {
global_ioc_cnt = count_parisc_driver(&sba_driver);
/* Astro and Pluto have one IOC per SBA */
if ((!IS_ASTRO(dev)) || (!IS_PLUTO(dev)))
global_ioc_cnt *= 2;
}
printk(KERN_INFO "%s found %s at 0x%llx\n",
MODULE_NAME, version, (unsigned long long)dev->hpa.start);
sba_dev = kzalloc(sizeof(struct sba_device), GFP_KERNEL);
if (!sba_dev) {
printk(KERN_ERR MODULE_NAME " - couldn't alloc sba_device\n");
return -ENOMEM;
}
parisc_set_drvdata(dev, sba_dev);
for(i=0; i<MAX_IOC; i++)
spin_lock_init(&(sba_dev->ioc[i].res_lock));
sba_dev->dev = dev;
sba_dev->hw_rev = func_class;
sba_dev->name = dev->name;
sba_dev->sba_hpa = sba_addr;
sba_get_pat_resources(sba_dev);
sba_hw_init(sba_dev);
sba_common_init(sba_dev);
hppa_dma_ops = &sba_ops;
#ifdef CONFIG_PROC_FS
switch (dev->id.hversion) {
case PLUTO_MCKINLEY_PORT:
root = proc_mckinley_root;
break;
case ASTRO_RUNWAY_PORT:
case IKE_MERCED_PORT:
default:
root = proc_runway_root;
break;
}
proc_create("sba_iommu", 0, root, &sba_proc_fops);
proc_create("sba_iommu-bitmap", 0, root, &sba_proc_bitmap_fops);
#endif
parisc_has_iommu();
return 0;
}
/*
** One time initialization to let the world know the SBA was found.
** This is the only routine which is NOT static.
** Must be called exactly once before pci_init().
*/
void __init sba_init(void)
{
register_parisc_driver(&sba_driver);
}
/**
* sba_get_iommu - Assign the iommu pointer for the pci bus controller.
* @dev: The parisc device.
*
* Returns the appropriate IOMMU data for the given parisc PCI controller.
* This is cached and used later for PCI DMA Mapping.
*/
void * sba_get_iommu(struct parisc_device *pci_hba)
{
struct parisc_device *sba_dev = parisc_parent(pci_hba);
struct sba_device *sba = dev_get_drvdata(&sba_dev->dev);
char t = sba_dev->id.hw_type;
int iocnum = (pci_hba->hw_path >> 3); /* rope # */
WARN_ON((t != HPHW_IOA) && (t != HPHW_BCPORT));
return &(sba->ioc[iocnum]);
}
/**
* sba_directed_lmmio - return first directed LMMIO range routed to rope
* @pa_dev: The parisc device.
* @r: resource PCI host controller wants start/end fields assigned.
*
* For the given parisc PCI controller, determine if any direct ranges
* are routed down the corresponding rope.
*/
void sba_directed_lmmio(struct parisc_device *pci_hba, struct resource *r)
{
struct parisc_device *sba_dev = parisc_parent(pci_hba);
struct sba_device *sba = dev_get_drvdata(&sba_dev->dev);
char t = sba_dev->id.hw_type;
int i;
int rope = (pci_hba->hw_path & (ROPES_PER_IOC-1)); /* rope # */
BUG_ON((t!=HPHW_IOA) && (t!=HPHW_BCPORT));
r->start = r->end = 0;
/* Astro has 4 directed ranges. Not sure about Ike/Pluto/et al */
for (i=0; i<4; i++) {
int base, size;
void __iomem *reg = sba->sba_hpa + i*0x18;
base = READ_REG32(reg + LMMIO_DIRECT0_BASE);
if ((base & 1) == 0)
continue; /* not enabled */
size = READ_REG32(reg + LMMIO_DIRECT0_ROUTE);
if ((size & (ROPES_PER_IOC-1)) != rope)
continue; /* directed down different rope */
r->start = (base & ~1UL) | PCI_F_EXTEND;
size = ~ READ_REG32(reg + LMMIO_DIRECT0_MASK);
r->end = r->start + size;
r->flags = IORESOURCE_MEM;
}
}
/**
* sba_distributed_lmmio - return portion of distributed LMMIO range
* @pa_dev: The parisc device.
* @r: resource PCI host controller wants start/end fields assigned.
*
* For the given parisc PCI controller, return portion of distributed LMMIO
* range. The distributed LMMIO is always present and it's just a question
* of the base address and size of the range.
*/
void sba_distributed_lmmio(struct parisc_device *pci_hba, struct resource *r )
{
struct parisc_device *sba_dev = parisc_parent(pci_hba);
struct sba_device *sba = dev_get_drvdata(&sba_dev->dev);
char t = sba_dev->id.hw_type;
int base, size;
int rope = (pci_hba->hw_path & (ROPES_PER_IOC-1)); /* rope # */
BUG_ON((t!=HPHW_IOA) && (t!=HPHW_BCPORT));
r->start = r->end = 0;
base = READ_REG32(sba->sba_hpa + LMMIO_DIST_BASE);
if ((base & 1) == 0) {
BUG(); /* Gah! Distr Range wasn't enabled! */
return;
}
r->start = (base & ~1UL) | PCI_F_EXTEND;
size = (~READ_REG32(sba->sba_hpa + LMMIO_DIST_MASK)) / ROPES_PER_IOC;
r->start += rope * (size + 1); /* adjust base for this rope */
r->end = r->start + size;
r->flags = IORESOURCE_MEM;
}