[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>
diff --git a/arch/sparc64/kernel/pci_iommu.c b/arch/sparc64/kernel/pci_iommu.c
index cdee7d9..a11910b 100644
--- a/arch/sparc64/kernel/pci_iommu.c
+++ b/arch/sparc64/kernel/pci_iommu.c
@@ -49,12 +49,6 @@
/* 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 @@
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 @@
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 @@
}
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 @@
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 @@
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 @@
((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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
/* 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 @@
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 @@
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 @@
}
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 @@
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 @@
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 @@
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);
diff --git a/include/asm-sparc64/pbm.h b/include/asm-sparc64/pbm.h
index c067407..dd35a2c 100644
--- a/include/asm-sparc64/pbm.h
+++ b/include/asm-sparc64/pbm.h
@@ -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 @@
*/
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 @@
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)];