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[SPARC64]: Eliminate PCI IOMMU dma mapping size limit. 

The hairy fast allocator in the sparc64 PCI IOMMU code
has a hard limit of 256 pages.  Certain devices can
exceed this when performing very large I/Os.

So replace with a more simple allocator, based largely
upon the arch/ppc64/kernel/iommu.c code.

Signed-off-by: David S. Miller <davem@davemloft.net>
5bit-waveforms
David S. Miller 2005-10-13 22:15:24 -07:00
parent 51e8513615
commit 688cb30bdc
2 changed files with 145 additions and 248 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

365
arch/sparc64/kernel/pci_iommu.c
View File

@ -49,12 +49,6 @@ static void __iommu_flushall(struct pci_iommu *iommu)
/* Ensure completion of previous PIO writes. */
(void) pci_iommu_read(iommu->write_complete_reg);
/* Now update everyone's flush point. */
for (entry = 0; entry < PBM_NCLUSTERS; entry++) {
iommu->alloc_info[entry].flush =
iommu->alloc_info[entry].next;
}
}
#define IOPTE_CONSISTENT(CTX) \
@ -80,9 +74,61 @@ static void inline iopte_make_dummy(struct pci_iommu *iommu, iopte_t *iopte)
iopte_val(*iopte) = val;
}
/* Based largely upon the ppc64 iommu allocator. */
static long pci_arena_alloc(struct pci_iommu *iommu, unsigned long npages)
{
struct pci_iommu_arena *arena = &iommu->arena;
unsigned long n, i, start, end, limit;
int pass;
limit = arena->limit;
start = arena->hint;
pass = 0;
again:
n = find_next_zero_bit(arena->map, limit, start);
end = n + npages;
if (unlikely(end >= limit)) {
if (likely(pass < 1)) {
limit = start;
start = 0;
__iommu_flushall(iommu);
pass++;
goto again;
} else {
/* Scanned the whole thing, give up. */
return -1;
}
}
for (i = n; i < end; i++) {
if (test_bit(i, arena->map)) {
start = i + 1;
goto again;
}
}
for (i = n; i < end; i++)
__set_bit(i, arena->map);
arena->hint = end;
return n;
}
static void pci_arena_free(struct pci_iommu_arena *arena, unsigned long base, unsigned long npages)
{
unsigned long i;
for (i = base; i < (base + npages); i++)
__clear_bit(i, arena->map);
}
void pci_iommu_table_init(struct pci_iommu *iommu, int tsbsize, u32 dma_offset, u32 dma_addr_mask)
{
unsigned long i, tsbbase, order;
unsigned long i, tsbbase, order, sz, num_tsb_entries;
num_tsb_entries = tsbsize / sizeof(iopte_t);
/* Setup initial software IOMMU state. */
spin_lock_init(&iommu->lock);
@ -90,27 +136,16 @@ void pci_iommu_table_init(struct pci_iommu *iommu, int tsbsize, u32 dma_offset,
iommu->page_table_map_base = dma_offset;
iommu->dma_addr_mask = dma_addr_mask;
switch (tsbsize / (8 * 1024)) {
case 64:
iommu->page_table_sz_bits = 16;
break;
case 128:
iommu->page_table_sz_bits = 17;
break;
default:
prom_printf("PCI_IOMMU: Illegal TSB size %d\n",
tsbsize / (8 * 1024));
/* Allocate and initialize the free area map. */
sz = num_tsb_entries / 8;
sz = (sz + 7UL) & ~7UL;
iommu->arena.map = kmalloc(sz, GFP_KERNEL);
if (!iommu->arena.map) {
prom_printf("PCI_IOMMU: Error, kmalloc(arena.map) failed.\n");
prom_halt();
break;
};
iommu->lowest_consistent_map =
1 << (iommu->page_table_sz_bits - PBM_LOGCLUSTERS);
for (i = 0; i < PBM_NCLUSTERS; i++) {
iommu->alloc_info[i].flush = 0;
iommu->alloc_info[i].next = 0;
}
memset(iommu->arena.map, 0, sz);
iommu->arena.limit = num_tsb_entries;
/* Allocate and initialize the dummy page which we
* set inactive IO PTEs to point to.
@ -132,114 +167,24 @@ void pci_iommu_table_init(struct pci_iommu *iommu, int tsbsize, u32 dma_offset,
}
iommu->page_table = (iopte_t *)tsbbase;
for (i = 0; i < tsbsize / sizeof(iopte_t); i++)
for (i = 0; i < num_tsb_entries; i++)
iopte_make_dummy(iommu, &iommu->page_table[i]);
}
static iopte_t *alloc_streaming_cluster(struct pci_iommu *iommu, unsigned long npages)
static inline iopte_t *alloc_npages(struct pci_iommu *iommu, unsigned long npages)
{
iopte_t *iopte, *limit, *first;
unsigned long cnum, ent, flush_point;
long entry;
cnum = 0;
while ((1UL << cnum) < npages)
cnum++;
iopte = (iommu->page_table +
(cnum << (iommu->page_table_sz_bits - PBM_LOGCLUSTERS)));
entry = pci_arena_alloc(iommu, npages);
if (unlikely(entry < 0))
return NULL;
if (cnum == 0)
limit = (iommu->page_table +
iommu->lowest_consistent_map);
else
limit = (iopte +
(1 << (iommu->page_table_sz_bits - PBM_LOGCLUSTERS)));
iopte += ((ent = iommu->alloc_info[cnum].next) << cnum);
flush_point = iommu->alloc_info[cnum].flush;
first = iopte;
for (;;) {
if (IOPTE_IS_DUMMY(iommu, iopte)) {
if ((iopte + (1 << cnum)) >= limit)
ent = 0;
else
ent = ent + 1;
iommu->alloc_info[cnum].next = ent;
if (ent == flush_point)
__iommu_flushall(iommu);
break;
}
iopte += (1 << cnum);
ent++;
if (iopte >= limit) {
iopte = (iommu->page_table +
(cnum <<
(iommu->page_table_sz_bits - PBM_LOGCLUSTERS)));
ent = 0;
}
if (ent == flush_point)
__iommu_flushall(iommu);
if (iopte == first)
goto bad;
}
/* I've got your streaming cluster right here buddy boy... */
return iopte;
bad:
printk(KERN_EMERG "pci_iommu: alloc_streaming_cluster of npages(%ld) failed!\n",
npages);
return NULL;
return iommu->page_table + entry;
}
static void free_streaming_cluster(struct pci_iommu *iommu, dma_addr_t base,
unsigned long npages, unsigned long ctx)
static inline void free_npages(struct pci_iommu *iommu, dma_addr_t base, unsigned long npages)
{
unsigned long cnum, ent;
cnum = 0;
while ((1UL << cnum) < npages)
cnum++;
ent = (base << (32 - IO_PAGE_SHIFT + PBM_LOGCLUSTERS - iommu->page_table_sz_bits))
>> (32 + PBM_LOGCLUSTERS + cnum - iommu->page_table_sz_bits);
/* If the global flush might not have caught this entry,
* adjust the flush point such that we will flush before
* ever trying to reuse it.
*/
#define between(X,Y,Z) (((Z) - (Y)) >= ((X) - (Y)))
if (between(ent, iommu->alloc_info[cnum].next, iommu->alloc_info[cnum].flush))
iommu->alloc_info[cnum].flush = ent;
#undef between
}
/* We allocate consistent mappings from the end of cluster zero. */
static iopte_t *alloc_consistent_cluster(struct pci_iommu *iommu, unsigned long npages)
{
iopte_t *iopte;
iopte = iommu->page_table + (1 << (iommu->page_table_sz_bits - PBM_LOGCLUSTERS));
while (iopte > iommu->page_table) {
iopte--;
if (IOPTE_IS_DUMMY(iommu, iopte)) {
unsigned long tmp = npages;
while (--tmp) {
iopte--;
if (!IOPTE_IS_DUMMY(iommu, iopte))
break;
}
if (tmp == 0) {
u32 entry = (iopte - iommu->page_table);
if (entry < iommu->lowest_consistent_map)
iommu->lowest_consistent_map = entry;
return iopte;
}
}
}
return NULL;
pci_arena_free(&iommu->arena, base >> IO_PAGE_SHIFT, npages);
}
static int iommu_alloc_ctx(struct pci_iommu *iommu)
@ -279,7 +224,7 @@ void *pci_alloc_consistent(struct pci_dev *pdev, size_t size, dma_addr_t *dma_ad
struct pcidev_cookie *pcp;
struct pci_iommu *iommu;
iopte_t *iopte;
unsigned long flags, order, first_page, ctx;
unsigned long flags, order, first_page;
void *ret;
int npages;
@ -297,9 +242,10 @@ void *pci_alloc_consistent(struct pci_dev *pdev, size_t size, dma_addr_t *dma_ad
iommu = pcp->pbm->iommu;
spin_lock_irqsave(&iommu->lock, flags);
iopte = alloc_consistent_cluster(iommu, size >> IO_PAGE_SHIFT);
if (iopte == NULL) {
spin_unlock_irqrestore(&iommu->lock, flags);
iopte = alloc_npages(iommu, size >> IO_PAGE_SHIFT);
spin_unlock_irqrestore(&iommu->lock, flags);
if (unlikely(iopte == NULL)) {
free_pages(first_page, order);
return NULL;
}
@ -308,31 +254,15 @@ void *pci_alloc_consistent(struct pci_dev *pdev, size_t size, dma_addr_t *dma_ad
((iopte - iommu->page_table) << IO_PAGE_SHIFT));
ret = (void *) first_page;
npages = size >> IO_PAGE_SHIFT;
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = iommu_alloc_ctx(iommu);
first_page = __pa(first_page);
while (npages--) {
iopte_val(*iopte) = (IOPTE_CONSISTENT(ctx) |
iopte_val(*iopte) = (IOPTE_CONSISTENT(0UL) |
IOPTE_WRITE |
(first_page & IOPTE_PAGE));
iopte++;
first_page += IO_PAGE_SIZE;
}
{
int i;
u32 daddr = *dma_addrp;
npages = size >> IO_PAGE_SHIFT;
for (i = 0; i < npages; i++) {
pci_iommu_write(iommu->iommu_flush, daddr);
daddr += IO_PAGE_SIZE;
}
}
spin_unlock_irqrestore(&iommu->lock, flags);
return ret;
}
@ -342,7 +272,7 @@ void pci_free_consistent(struct pci_dev *pdev, size_t size, void *cpu, dma_addr_
struct pcidev_cookie *pcp;
struct pci_iommu *iommu;
iopte_t *iopte;
unsigned long flags, order, npages, i, ctx;
unsigned long flags, order, npages;
npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
pcp = pdev->sysdata;
@ -352,46 +282,7 @@ void pci_free_consistent(struct pci_dev *pdev, size_t size, void *cpu, dma_addr_
spin_lock_irqsave(&iommu->lock, flags);
if ((iopte - iommu->page_table) ==
iommu->lowest_consistent_map) {
iopte_t *walk = iopte + npages;
iopte_t *limit;
limit = (iommu->page_table +
(1 << (iommu->page_table_sz_bits - PBM_LOGCLUSTERS)));
while (walk < limit) {
if (!IOPTE_IS_DUMMY(iommu, walk))
break;
walk++;
}
iommu->lowest_consistent_map =
(walk - iommu->page_table);
}
/* Data for consistent mappings cannot enter the streaming
* buffers, so we only need to update the TSB. We flush
* the IOMMU here as well to prevent conflicts with the
* streaming mapping deferred tlb flush scheme.
*/
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
for (i = 0; i < npages; i++, iopte++)
iopte_make_dummy(iommu, iopte);
if (iommu->iommu_ctxflush) {
pci_iommu_write(iommu->iommu_ctxflush, ctx);
} else {
for (i = 0; i < npages; i++) {
u32 daddr = dvma + (i << IO_PAGE_SHIFT);
pci_iommu_write(iommu->iommu_flush, daddr);
}
}
iommu_free_ctx(iommu, ctx);
free_npages(iommu, dvma, npages);
spin_unlock_irqrestore(&iommu->lock, flags);
@ -418,25 +309,27 @@ dma_addr_t pci_map_single(struct pci_dev *pdev, void *ptr, size_t sz, int direct
iommu = pcp->pbm->iommu;
strbuf = &pcp->pbm->stc;
if (direction == PCI_DMA_NONE)
BUG();
if (unlikely(direction == PCI_DMA_NONE))
goto bad_no_ctx;
oaddr = (unsigned long)ptr;
npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
npages >>= IO_PAGE_SHIFT;
spin_lock_irqsave(&iommu->lock, flags);
base = alloc_npages(iommu, npages);
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = iommu_alloc_ctx(iommu);
spin_unlock_irqrestore(&iommu->lock, flags);
base = alloc_streaming_cluster(iommu, npages);
if (base == NULL)
if (unlikely(!base))
goto bad;
bus_addr = (iommu->page_table_map_base +
((base - iommu->page_table) << IO_PAGE_SHIFT));
ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
base_paddr = __pa(oaddr & IO_PAGE_MASK);
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = iommu_alloc_ctx(iommu);
if (strbuf->strbuf_enabled)
iopte_protection = IOPTE_STREAMING(ctx);
else
@ -447,12 +340,13 @@ dma_addr_t pci_map_single(struct pci_dev *pdev, void *ptr, size_t sz, int direct
for (i = 0; i < npages; i++, base++, base_paddr += IO_PAGE_SIZE)
iopte_val(*base) = iopte_protection | base_paddr;
spin_unlock_irqrestore(&iommu->lock, flags);
return ret;
bad:
spin_unlock_irqrestore(&iommu->lock, flags);
iommu_free_ctx(iommu, ctx);
bad_no_ctx:
if (printk_ratelimit())
WARN_ON(1);
return PCI_DMA_ERROR_CODE;
}
@ -527,10 +421,13 @@ void pci_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int
struct pci_iommu *iommu;
struct pci_strbuf *strbuf;
iopte_t *base;
unsigned long flags, npages, ctx;
unsigned long flags, npages, ctx, i;
if (direction == PCI_DMA_NONE)
BUG();
if (unlikely(direction == PCI_DMA_NONE)) {
if (printk_ratelimit())
WARN_ON(1);
return;
}
pcp = pdev->sysdata;
iommu = pcp->pbm->iommu;
@ -556,13 +453,14 @@ void pci_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int
/* Step 1: Kick data out of streaming buffers if necessary. */
if (strbuf->strbuf_enabled)
pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
pci_strbuf_flush(strbuf, iommu, bus_addr, ctx,
npages, direction);
/* Step 2: Clear out first TSB entry. */
iopte_make_dummy(iommu, base);
/* Step 2: Clear out TSB entries. */
for (i = 0; i < npages; i++)
iopte_make_dummy(iommu, base + i);
free_streaming_cluster(iommu, bus_addr - iommu->page_table_map_base,
npages, ctx);
free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);
iommu_free_ctx(iommu, ctx);
@ -667,6 +565,8 @@ int pci_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int
pci_map_single(pdev,
(page_address(sglist->page) + sglist->offset),
sglist->length, direction);
if (unlikely(sglist->dma_address == PCI_DMA_ERROR_CODE))
return 0;
sglist->dma_length = sglist->length;
return 1;
}
@ -675,21 +575,29 @@ int pci_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int
iommu = pcp->pbm->iommu;
strbuf = &pcp->pbm->stc;
if (direction == PCI_DMA_NONE)
BUG();
if (unlikely(direction == PCI_DMA_NONE))
goto bad_no_ctx;
/* Step 1: Prepare scatter list. */
npages = prepare_sg(sglist, nelems);
/* Step 2: Allocate a cluster. */
/* Step 2: Allocate a cluster and context, if necessary. */
spin_lock_irqsave(&iommu->lock, flags);
base = alloc_streaming_cluster(iommu, npages);
base = alloc_npages(iommu, npages);
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = iommu_alloc_ctx(iommu);
spin_unlock_irqrestore(&iommu->lock, flags);
if (base == NULL)
goto bad;
dma_base = iommu->page_table_map_base + ((base - iommu->page_table) << IO_PAGE_SHIFT);
dma_base = iommu->page_table_map_base +
((base - iommu->page_table) << IO_PAGE_SHIFT);
/* Step 3: Normalize DMA addresses. */
used = nelems;
@ -702,30 +610,28 @@ int pci_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int
}
used = nelems - used;
/* Step 4: Choose a context if necessary. */
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = iommu_alloc_ctx(iommu);
/* Step 5: Create the mappings. */
/* Step 4: Create the mappings. */
if (strbuf->strbuf_enabled)
iopte_protection = IOPTE_STREAMING(ctx);
else
iopte_protection = IOPTE_CONSISTENT(ctx);
if (direction != PCI_DMA_TODEVICE)
iopte_protection |= IOPTE_WRITE;
fill_sg (base, sglist, used, nelems, iopte_protection);
fill_sg(base, sglist, used, nelems, iopte_protection);
#ifdef VERIFY_SG
verify_sglist(sglist, nelems, base, npages);
#endif
spin_unlock_irqrestore(&iommu->lock, flags);
return used;
bad:
spin_unlock_irqrestore(&iommu->lock, flags);
return PCI_DMA_ERROR_CODE;
iommu_free_ctx(iommu, ctx);
bad_no_ctx:
if (printk_ratelimit())
WARN_ON(1);
return 0;
}
/* Unmap a set of streaming mode DMA translations. */
@ -738,8 +644,10 @@ void pci_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems,
unsigned long flags, ctx, i, npages;
u32 bus_addr;
if (direction == PCI_DMA_NONE)
BUG();
if (unlikely(direction == PCI_DMA_NONE)) {
if (printk_ratelimit())
WARN_ON(1);
}
pcp = pdev->sysdata;
iommu = pcp->pbm->iommu;
@ -751,7 +659,8 @@ void pci_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems,
if (sglist[i].dma_length == 0)
break;
i--;
npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) - bus_addr) >> IO_PAGE_SHIFT;
npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
bus_addr) >> IO_PAGE_SHIFT;
base = iommu->page_table +
((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
@ -772,11 +681,11 @@ void pci_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems,
if (strbuf->strbuf_enabled)
pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
/* Step 2: Clear out first TSB entry. */
iopte_make_dummy(iommu, base);
/* Step 2: Clear out the TSB entries. */
for (i = 0; i < npages; i++)
iopte_make_dummy(iommu, base + i);
free_streaming_cluster(iommu, bus_addr - iommu->page_table_map_base,
npages, ctx);
free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);
iommu_free_ctx(iommu, ctx);

28
include/asm-sparc64/pbm.h
View File

@ -27,23 +27,27 @@
* PCI bus.
*/
#define PBM_LOGCLUSTERS 3
#define PBM_NCLUSTERS (1 << PBM_LOGCLUSTERS)
struct pci_controller_info;
/* This contains the software state necessary to drive a PCI
* controller's IOMMU.
*/
struct pci_iommu_arena {
unsigned long *map;
unsigned int hint;
unsigned int limit;
};
struct pci_iommu {
/* This protects the controller's IOMMU and all
* streaming buffers underneath.
*/
spinlock_t lock;
struct pci_iommu_arena arena;
/* IOMMU page table, a linear array of ioptes. */
iopte_t *page_table; /* The page table itself. */
int page_table_sz_bits; /* log2 of ow many pages does it map? */
/* Base PCI memory space address where IOMMU mappings
* begin.
@ -62,12 +66,6 @@ struct pci_iommu {
*/
unsigned long write_complete_reg;
/* The lowest used consistent mapping entry. Since
* we allocate consistent maps out of cluster 0 this
* is relative to the beginning of closter 0.
*/
u32 lowest_consistent_map;
/* In order to deal with some buggy third-party PCI bridges that
* do wrong prefetching, we never mark valid mappings as invalid.
* Instead we point them at this dummy page.
@ -75,16 +73,6 @@ struct pci_iommu {
unsigned long dummy_page;
unsigned long dummy_page_pa;
/* If PBM_NCLUSTERS is ever decreased to 4 or lower,
* or if largest supported page_table_sz * 8K goes above
* 2GB, you must increase the size of the type of
* these counters. You have been duly warned. -DaveM
*/
struct {
u16 next;
u16 flush;
} alloc_info[PBM_NCLUSTERS];
/* CTX allocation. */
unsigned long ctx_lowest_free;
unsigned long ctx_bitmap[IOMMU_NUM_CTXS / (sizeof(unsigned long) * 8)];