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alpha: make IOMMU respect the segment boundary limits

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This patch makes the IOMMU code not allocate a memory area spanning LLD's
segment boundary.

is_span_boundary() judges whether a memory area spans LLD's segment boundary.
If iommu_arena_find_pages() finds such a area, it tries to find the next
available memory area.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
FUJITA Tomonori 2008-03-04 14:28:57 -08:00 committed by Linus Torvalds
parent 23d7e0390a
commit cf54014548
1 changed files with 34 additions and 6 deletions
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40
arch/alpha/kernel/pci_iommu.c
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@ -126,13 +126,34 @@ iommu_arena_new(struct pci_controller *hose, dma_addr_t base,
return iommu_arena_new_node(0, hose, base, window_size, align);
}
static inline int is_span_boundary(unsigned int index, unsigned int nr,
unsigned long shift,
unsigned long boundary_size)
{
shift = (shift + index) & (boundary_size - 1);
return shift + nr > boundary_size;
}
/* Must be called with the arena lock held */
static long
iommu_arena_find_pages(struct pci_iommu_arena *arena, long n, long mask)
iommu_arena_find_pages(struct device *dev, struct pci_iommu_arena *arena,
long n, long mask)
{
unsigned long *ptes;
long i, p, nent;
int pass = 0;
unsigned long base;
unsigned long boundary_size;
BUG_ON(arena->dma_base & ~PAGE_MASK);
base = arena->dma_base >> PAGE_SHIFT;
if (dev)
boundary_size = ALIGN(dma_get_max_seg_size(dev) + 1, PAGE_SIZE)
>> PAGE_SHIFT;
else
boundary_size = ALIGN(1UL << 32, PAGE_SIZE) >> PAGE_SHIFT;
BUG_ON(!is_power_of_2(boundary_size));
/* Search forward for the first mask-aligned sequence of N free ptes */
ptes = arena->ptes;
@ -142,6 +163,11 @@ iommu_arena_find_pages(struct pci_iommu_arena *arena, long n, long mask)
again:
while (i < n && p+i < nent) {
if (!i && is_span_boundary(p, n, base, boundary_size)) {
p = ALIGN(p + 1, mask + 1);
goto again;
}
if (ptes[p+i])
p = ALIGN(p + i + 1, mask + 1), i = 0;
else
@ -170,7 +196,8 @@ again:
}
static long
iommu_arena_alloc(struct pci_iommu_arena *arena, long n, unsigned int align)
iommu_arena_alloc(struct device *dev, struct pci_iommu_arena *arena, long n,
unsigned int align)
{
unsigned long flags;
unsigned long *ptes;
@ -181,7 +208,7 @@ iommu_arena_alloc(struct pci_iommu_arena *arena, long n, unsigned int align)
/* Search for N empty ptes */
ptes = arena->ptes;
mask = max(align, arena->align_entry) - 1;
p = iommu_arena_find_pages(arena, n, mask);
p = iommu_arena_find_pages(dev, arena, n, mask);
if (p < 0) {
spin_unlock_irqrestore(&arena->lock, flags);
return -1;
@ -231,6 +258,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
unsigned long paddr;
dma_addr_t ret;
unsigned int align = 0;
struct device *dev = pdev ? &pdev->dev : NULL;
paddr = __pa(cpu_addr);
@ -278,7 +306,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
/* Force allocation to 64KB boundary for ISA bridges. */
if (pdev && pdev == isa_bridge)
align = 8;
dma_ofs = iommu_arena_alloc(arena, npages, align);
dma_ofs = iommu_arena_alloc(dev, arena, npages, align);
if (dma_ofs < 0) {
printk(KERN_WARNING "pci_map_single failed: "
"could not allocate dma page tables\n");
@ -565,7 +593,7 @@ sg_fill(struct device *dev, struct scatterlist *leader, struct scatterlist *end,
paddr &= ~PAGE_MASK;
npages = calc_npages(paddr + size);
dma_ofs = iommu_arena_alloc(arena, npages, 0);
dma_ofs = iommu_arena_alloc(dev, arena, npages, 0);
if (dma_ofs < 0) {
/* If we attempted a direct map above but failed, die. */
if (leader->dma_address == 0)
@ -832,7 +860,7 @@ iommu_reserve(struct pci_iommu_arena *arena, long pg_count, long align_mask)
/* Search for N empty ptes. */
ptes = arena->ptes;
p = iommu_arena_find_pages(arena, pg_count, align_mask);
p = iommu_arena_find_pages(NULL, arena, pg_count, align_mask);
if (p < 0) {
spin_unlock_irqrestore(&arena->lock, flags);
return -1;