From cf5401454863df8e6dc3ebe8faad09141cbec187 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Tue, 4 Mar 2008 14:28:57 -0800 Subject: [PATCH] alpha: make IOMMU respect the segment boundary limits 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 Cc: Richard Henderson Cc: Ivan Kokshaysky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/alpha/kernel/pci_iommu.c | 40 +++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 6 deletions(-) diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c index e54f829528cb..54540c369c90 100644 --- a/arch/alpha/kernel/pci_iommu.c +++ b/arch/alpha/kernel/pci_iommu.c @@ -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; -- 2.30.2