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Diffstat (limited to 'arch/sparc64/kernel/iommu.c')
-rw-r--r--arch/sparc64/kernel/iommu.c352
1 files changed, 237 insertions, 115 deletions
diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
index 5623a4d59df..d3276ebcfb4 100644
--- a/arch/sparc64/kernel/iommu.c
+++ b/arch/sparc64/kernel/iommu.c
@@ -1,6 +1,6 @@
/* iommu.c: Generic sparc64 IOMMU support.
*
- * Copyright (C) 1999, 2007 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
* Copyright (C) 1999, 2000 Jakub Jelinek (jakub@redhat.com)
*/
@@ -10,6 +10,7 @@
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
+#include <linux/iommu-helper.h>
#ifdef CONFIG_PCI
#include <linux/pci.h>
@@ -41,7 +42,7 @@
"i" (ASI_PHYS_BYPASS_EC_E))
/* Must be invoked under the IOMMU lock. */
-static void __iommu_flushall(struct iommu *iommu)
+static void iommu_flushall(struct iommu *iommu)
{
if (iommu->iommu_flushinv) {
iommu_write(iommu->iommu_flushinv, ~(u64)0);
@@ -83,54 +84,91 @@ static inline void iopte_make_dummy(struct iommu *iommu, iopte_t *iopte)
iopte_val(*iopte) = val;
}
-/* Based largely upon the ppc64 iommu allocator. */
-static long arena_alloc(struct iommu *iommu, unsigned long npages)
+/* Based almost entirely upon the ppc64 iommu allocator. If you use the 'handle'
+ * facility it must all be done in one pass while under the iommu lock.
+ *
+ * On sun4u platforms, we only flush the IOMMU once every time we've passed
+ * over the entire page table doing allocations. Therefore we only ever advance
+ * the hint and cannot backtrack it.
+ */
+unsigned long iommu_range_alloc(struct device *dev,
+ struct iommu *iommu,
+ unsigned long npages,
+ unsigned long *handle)
{
+ unsigned long n, end, start, limit, boundary_size;
struct iommu_arena *arena = &iommu->arena;
- unsigned long n, i, start, end, limit;
- int pass;
+ int pass = 0;
+
+ /* This allocator was derived from x86_64's bit string search */
+
+ /* Sanity check */
+ if (unlikely(npages == 0)) {
+ if (printk_ratelimit())
+ WARN_ON(1);
+ return DMA_ERROR_CODE;
+ }
+
+ if (handle && *handle)
+ start = *handle;
+ else
+ start = arena->hint;
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)) {
+ /* The case below can happen if we have a small segment appended
+ * to a large, or when the previous alloc was at the very end of
+ * the available space. If so, go back to the beginning and flush.
+ */
+ if (start >= limit) {
+ start = 0;
+ if (iommu->flush_all)
+ iommu->flush_all(iommu);
+ }
+
+ again:
+
+ if (dev)
+ boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
+ 1 << IO_PAGE_SHIFT);
+ else
+ boundary_size = ALIGN(1UL << 32, 1 << IO_PAGE_SHIFT);
+
+ n = iommu_area_alloc(arena->map, limit, start, npages, 0,
+ boundary_size >> IO_PAGE_SHIFT, 0);
+ if (n == -1) {
if (likely(pass < 1)) {
- limit = start;
+ /* First failure, rescan from the beginning. */
start = 0;
- __iommu_flushall(iommu);
+ if (iommu->flush_all)
+ iommu->flush_all(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;
+ /* Second failure, give up */
+ return DMA_ERROR_CODE;
}
}
- for (i = n; i < end; i++)
- __set_bit(i, arena->map);
+ end = n + npages;
arena->hint = end;
+ /* Update handle for SG allocations */
+ if (handle)
+ *handle = end;
+
return n;
}
-static void arena_free(struct iommu_arena *arena, unsigned long base, unsigned long npages)
+void iommu_range_free(struct iommu *iommu, dma_addr_t dma_addr, unsigned long npages)
{
- unsigned long i;
+ struct iommu_arena *arena = &iommu->arena;
+ unsigned long entry;
- for (i = base; i < (base + npages); i++)
- __clear_bit(i, arena->map);
+ entry = (dma_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
+
+ iommu_area_free(arena->map, entry, npages);
}
int iommu_table_init(struct iommu *iommu, int tsbsize,
@@ -156,6 +194,9 @@ int iommu_table_init(struct iommu *iommu, int tsbsize,
}
iommu->arena.limit = num_tsb_entries;
+ if (tlb_type != hypervisor)
+ iommu->flush_all = iommu_flushall;
+
/* Allocate and initialize the dummy page which we
* set inactive IO PTEs to point to.
*/
@@ -192,22 +233,18 @@ out_free_map:
return -ENOMEM;
}
-static inline iopte_t *alloc_npages(struct iommu *iommu, unsigned long npages)
+static inline iopte_t *alloc_npages(struct device *dev, struct iommu *iommu,
+ unsigned long npages)
{
- long entry;
+ unsigned long entry;
- entry = arena_alloc(iommu, npages);
- if (unlikely(entry < 0))
+ entry = iommu_range_alloc(dev, iommu, npages, NULL);
+ if (unlikely(entry == DMA_ERROR_CODE))
return NULL;
return iommu->page_table + entry;
}
-static inline void free_npages(struct iommu *iommu, dma_addr_t base, unsigned long npages)
-{
- arena_free(&iommu->arena, base >> IO_PAGE_SHIFT, npages);
-}
-
static int iommu_alloc_ctx(struct iommu *iommu)
{
int lowest = iommu->ctx_lowest_free;
@@ -258,7 +295,7 @@ static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
iommu = dev->archdata.iommu;
spin_lock_irqsave(&iommu->lock, flags);
- iopte = alloc_npages(iommu, size >> IO_PAGE_SHIFT);
+ iopte = alloc_npages(dev, iommu, size >> IO_PAGE_SHIFT);
spin_unlock_irqrestore(&iommu->lock, flags);
if (unlikely(iopte == NULL)) {
@@ -296,7 +333,7 @@ static void dma_4u_free_coherent(struct device *dev, size_t size,
spin_lock_irqsave(&iommu->lock, flags);
- free_npages(iommu, dvma - iommu->page_table_map_base, npages);
+ iommu_range_free(iommu, dvma, npages);
spin_unlock_irqrestore(&iommu->lock, flags);
@@ -327,7 +364,7 @@ static dma_addr_t dma_4u_map_single(struct device *dev, void *ptr, size_t sz,
npages >>= IO_PAGE_SHIFT;
spin_lock_irqsave(&iommu->lock, flags);
- base = alloc_npages(iommu, npages);
+ base = alloc_npages(dev, iommu, npages);
ctx = 0;
if (iommu->iommu_ctxflush)
ctx = iommu_alloc_ctx(iommu);
@@ -465,7 +502,7 @@ static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr,
for (i = 0; i < npages; i++)
iopte_make_dummy(iommu, base + i);
- free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);
+ iommu_range_free(iommu, bus_addr, npages);
iommu_free_ctx(iommu, ctx);
@@ -475,124 +512,209 @@ static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr,
static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
- unsigned long flags, ctx, i, npages, iopte_protection;
- struct scatterlist *sg;
+ struct scatterlist *s, *outs, *segstart;
+ unsigned long flags, handle, prot, ctx;
+ dma_addr_t dma_next = 0, dma_addr;
+ unsigned int max_seg_size;
+ int outcount, incount, i;
struct strbuf *strbuf;
struct iommu *iommu;
- iopte_t *base;
- u32 dma_base;
-
- /* Fast path single entry scatterlists. */
- if (nelems == 1) {
- sglist->dma_address =
- dma_4u_map_single(dev, sg_virt(sglist),
- sglist->length, direction);
- if (unlikely(sglist->dma_address == DMA_ERROR_CODE))
- return 0;
- sglist->dma_length = sglist->length;
- return 1;
- }
+
+ BUG_ON(direction == DMA_NONE);
iommu = dev->archdata.iommu;
strbuf = dev->archdata.stc;
-
- if (unlikely(direction == DMA_NONE))
- goto bad_no_ctx;
-
- npages = calc_npages(sglist, nelems);
+ if (nelems == 0 || !iommu)
+ return 0;
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);
-
- if (base == NULL)
- goto bad;
-
- dma_base = iommu->page_table_map_base +
- ((base - iommu->page_table) << IO_PAGE_SHIFT);
-
if (strbuf->strbuf_enabled)
- iopte_protection = IOPTE_STREAMING(ctx);
+ prot = IOPTE_STREAMING(ctx);
else
- iopte_protection = IOPTE_CONSISTENT(ctx);
+ prot = IOPTE_CONSISTENT(ctx);
if (direction != DMA_TO_DEVICE)
- iopte_protection |= IOPTE_WRITE;
-
- for_each_sg(sglist, sg, nelems, i) {
- unsigned long paddr = SG_ENT_PHYS_ADDRESS(sg);
- unsigned long slen = sg->length;
- unsigned long this_npages;
+ prot |= IOPTE_WRITE;
+
+ outs = s = segstart = &sglist[0];
+ outcount = 1;
+ incount = nelems;
+ handle = 0;
+
+ /* Init first segment length for backout at failure */
+ outs->dma_length = 0;
+
+ max_seg_size = dma_get_max_seg_size(dev);
+ for_each_sg(sglist, s, nelems, i) {
+ unsigned long paddr, npages, entry, slen;
+ iopte_t *base;
+
+ slen = s->length;
+ /* Sanity check */
+ if (slen == 0) {
+ dma_next = 0;
+ continue;
+ }
+ /* Allocate iommu entries for that segment */
+ paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
+ npages = iommu_num_pages(paddr, slen);
+ entry = iommu_range_alloc(dev, iommu, npages, &handle);
+
+ /* Handle failure */
+ if (unlikely(entry == DMA_ERROR_CODE)) {
+ if (printk_ratelimit())
+ printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
+ " npages %lx\n", iommu, paddr, npages);
+ goto iommu_map_failed;
+ }
- this_npages = iommu_num_pages(paddr, slen);
+ base = iommu->page_table + entry;
- sg->dma_address = dma_base | (paddr & ~IO_PAGE_MASK);
- sg->dma_length = slen;
+ /* Convert entry to a dma_addr_t */
+ dma_addr = iommu->page_table_map_base +
+ (entry << IO_PAGE_SHIFT);
+ dma_addr |= (s->offset & ~IO_PAGE_MASK);
+ /* Insert into HW table */
paddr &= IO_PAGE_MASK;
- while (this_npages--) {
- iopte_val(*base) = iopte_protection | paddr;
-
+ while (npages--) {
+ iopte_val(*base) = prot | paddr;
base++;
paddr += IO_PAGE_SIZE;
- dma_base += IO_PAGE_SIZE;
}
+
+ /* If we are in an open segment, try merging */
+ if (segstart != s) {
+ /* We cannot merge if:
+ * - allocated dma_addr isn't contiguous to previous allocation
+ */
+ if ((dma_addr != dma_next) ||
+ (outs->dma_length + s->length > max_seg_size)) {
+ /* Can't merge: create a new segment */
+ segstart = s;
+ outcount++;
+ outs = sg_next(outs);
+ } else {
+ outs->dma_length += s->length;
+ }
+ }
+
+ if (segstart == s) {
+ /* This is a new segment, fill entries */
+ outs->dma_address = dma_addr;
+ outs->dma_length = slen;
+ }
+
+ /* Calculate next page pointer for contiguous check */
+ dma_next = dma_addr + slen;
}
- return nelems;
+ spin_unlock_irqrestore(&iommu->lock, flags);
+
+ if (outcount < incount) {
+ outs = sg_next(outs);
+ outs->dma_address = DMA_ERROR_CODE;
+ outs->dma_length = 0;
+ }
+
+ return outcount;
+
+iommu_map_failed:
+ for_each_sg(sglist, s, nelems, i) {
+ if (s->dma_length != 0) {
+ unsigned long vaddr, npages, entry, i;
+ iopte_t *base;
+
+ vaddr = s->dma_address & IO_PAGE_MASK;
+ npages = iommu_num_pages(s->dma_address, s->dma_length);
+ iommu_range_free(iommu, vaddr, npages);
+
+ entry = (vaddr - iommu->page_table_map_base)
+ >> IO_PAGE_SHIFT;
+ base = iommu->page_table + entry;
+
+ for (i = 0; i < npages; i++)
+ iopte_make_dummy(iommu, base + i);
+
+ s->dma_address = DMA_ERROR_CODE;
+ s->dma_length = 0;
+ }
+ if (s == outs)
+ break;
+ }
+ spin_unlock_irqrestore(&iommu->lock, flags);
-bad:
- iommu_free_ctx(iommu, ctx);
-bad_no_ctx:
- if (printk_ratelimit())
- WARN_ON(1);
return 0;
}
+/* If contexts are being used, they are the same in all of the mappings
+ * we make for a particular SG.
+ */
+static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
+{
+ unsigned long ctx = 0;
+
+ if (iommu->iommu_ctxflush) {
+ iopte_t *base;
+ u32 bus_addr;
+
+ bus_addr = sg->dma_address & IO_PAGE_MASK;
+ base = iommu->page_table +
+ ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+
+ ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
+ }
+ return ctx;
+}
+
static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
- unsigned long flags, ctx, i, npages;
+ unsigned long flags, ctx;
+ struct scatterlist *sg;
struct strbuf *strbuf;
struct iommu *iommu;
- iopte_t *base;
- u32 bus_addr;
- if (unlikely(direction == DMA_NONE)) {
- if (printk_ratelimit())
- WARN_ON(1);
- }
+ BUG_ON(direction == DMA_NONE);
iommu = dev->archdata.iommu;
strbuf = dev->archdata.stc;
- bus_addr = sglist->dma_address & IO_PAGE_MASK;
+ ctx = fetch_sg_ctx(iommu, sglist);
- npages = calc_npages(sglist, nelems);
+ spin_lock_irqsave(&iommu->lock, flags);
- base = iommu->page_table +
- ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+ sg = sglist;
+ while (nelems--) {
+ dma_addr_t dma_handle = sg->dma_address;
+ unsigned int len = sg->dma_length;
+ unsigned long npages, entry;
+ iopte_t *base;
+ int i;
- spin_lock_irqsave(&iommu->lock, flags);
+ if (!len)
+ break;
+ npages = iommu_num_pages(dma_handle, len);
+ iommu_range_free(iommu, dma_handle, npages);
- /* Record the context, if any. */
- ctx = 0;
- if (iommu->iommu_ctxflush)
- ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
+ entry = ((dma_handle - iommu->page_table_map_base)
+ >> IO_PAGE_SHIFT);
+ base = iommu->page_table + entry;
- /* Step 1: Kick data out of streaming buffers if necessary. */
- if (strbuf->strbuf_enabled)
- strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
+ dma_handle &= IO_PAGE_MASK;
+ if (strbuf->strbuf_enabled)
+ strbuf_flush(strbuf, iommu, dma_handle, ctx,
+ npages, direction);
- /* Step 2: Clear out the TSB entries. */
- for (i = 0; i < npages; i++)
- iopte_make_dummy(iommu, base + i);
+ for (i = 0; i < npages; i++)
+ iopte_make_dummy(iommu, base + i);
- free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);
+ sg = sg_next(sg);
+ }
iommu_free_ctx(iommu, ctx);