diff options
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 1346 |
1 files changed, 1147 insertions, 199 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index db23ae4aaaa..106c4c0ebcc 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -17,8 +17,12 @@ #include <linux/init.h> #include <linux/device.h> #include <linux/dma-mapping.h> +#include <linux/dma-contiguous.h> #include <linux/highmem.h> +#include <linux/memblock.h> #include <linux/slab.h> +#include <linux/iommu.h> +#include <linux/vmalloc.h> #include <asm/memory.h> #include <asm/highmem.h> @@ -26,9 +30,112 @@ #include <asm/tlbflush.h> #include <asm/sizes.h> #include <asm/mach/arch.h> +#include <asm/dma-iommu.h> +#include <asm/mach/map.h> +#include <asm/system_info.h> +#include <asm/dma-contiguous.h> #include "mm.h" +/* + * The DMA API is built upon the notion of "buffer ownership". A buffer + * is either exclusively owned by the CPU (and therefore may be accessed + * by it) or exclusively owned by the DMA device. These helper functions + * represent the transitions between these two ownership states. + * + * Note, however, that on later ARMs, this notion does not work due to + * speculative prefetches. We model our approach on the assumption that + * the CPU does do speculative prefetches, which means we clean caches + * before transfers and delay cache invalidation until transfer completion. + * + */ +static void __dma_page_cpu_to_dev(struct page *, unsigned long, + size_t, enum dma_data_direction); +static void __dma_page_dev_to_cpu(struct page *, unsigned long, + size_t, enum dma_data_direction); + +/** + * arm_dma_map_page - map a portion of a page for streaming DMA + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @page: page that buffer resides in + * @offset: offset into page for start of buffer + * @size: size of buffer to map + * @dir: DMA transfer direction + * + * Ensure that any data held in the cache is appropriately discarded + * or written back. + * + * The device owns this memory once this call has completed. The CPU + * can regain ownership by calling dma_unmap_page(). + */ +static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + if (!arch_is_coherent()) + __dma_page_cpu_to_dev(page, offset, size, dir); + return pfn_to_dma(dev, page_to_pfn(page)) + offset; +} + +/** + * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page() + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @handle: DMA address of buffer + * @size: size of buffer (same as passed to dma_map_page) + * @dir: DMA transfer direction (same as passed to dma_map_page) + * + * Unmap a page streaming mode DMA translation. The handle and size + * must match what was provided in the previous dma_map_page() call. + * All other usages are undefined. + * + * After this call, reads by the CPU to the buffer are guaranteed to see + * whatever the device wrote there. + */ +static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + if (!arch_is_coherent()) + __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)), + handle & ~PAGE_MASK, size, dir); +} + +static void arm_dma_sync_single_for_cpu(struct device *dev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ + unsigned int offset = handle & (PAGE_SIZE - 1); + struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset)); + if (!arch_is_coherent()) + __dma_page_dev_to_cpu(page, offset, size, dir); +} + +static void arm_dma_sync_single_for_device(struct device *dev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ + unsigned int offset = handle & (PAGE_SIZE - 1); + struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset)); + if (!arch_is_coherent()) + __dma_page_cpu_to_dev(page, offset, size, dir); +} + +static int arm_dma_set_mask(struct device *dev, u64 dma_mask); + +struct dma_map_ops arm_dma_ops = { + .alloc = arm_dma_alloc, + .free = arm_dma_free, + .mmap = arm_dma_mmap, + .map_page = arm_dma_map_page, + .unmap_page = arm_dma_unmap_page, + .map_sg = arm_dma_map_sg, + .unmap_sg = arm_dma_unmap_sg, + .sync_single_for_cpu = arm_dma_sync_single_for_cpu, + .sync_single_for_device = arm_dma_sync_single_for_device, + .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu, + .sync_sg_for_device = arm_dma_sync_sg_for_device, + .set_dma_mask = arm_dma_set_mask, +}; +EXPORT_SYMBOL(arm_dma_ops); + static u64 get_coherent_dma_mask(struct device *dev) { u64 mask = (u64)arm_dma_limit; @@ -56,6 +163,21 @@ static u64 get_coherent_dma_mask(struct device *dev) return mask; } +static void __dma_clear_buffer(struct page *page, size_t size) +{ + void *ptr; + /* + * Ensure that the allocated pages are zeroed, and that any data + * lurking in the kernel direct-mapped region is invalidated. + */ + ptr = page_address(page); + if (ptr) { + memset(ptr, 0, size); + dmac_flush_range(ptr, ptr + size); + outer_flush_range(__pa(ptr), __pa(ptr) + size); + } +} + /* * Allocate a DMA buffer for 'dev' of size 'size' using the * specified gfp mask. Note that 'size' must be page aligned. @@ -64,23 +186,6 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gf { unsigned long order = get_order(size); struct page *page, *p, *e; - void *ptr; - u64 mask = get_coherent_dma_mask(dev); - -#ifdef CONFIG_DMA_API_DEBUG - u64 limit = (mask + 1) & ~mask; - if (limit && size >= limit) { - dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n", - size, mask); - return NULL; - } -#endif - - if (!mask) - return NULL; - - if (mask < 0xffffffffULL) - gfp |= GFP_DMA; page = alloc_pages(gfp, order); if (!page) @@ -93,14 +198,7 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gf for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++) __free_page(p); - /* - * Ensure that the allocated pages are zeroed, and that any data - * lurking in the kernel direct-mapped region is invalidated. - */ - ptr = page_address(page); - memset(ptr, 0, size); - dmac_flush_range(ptr, ptr + size); - outer_flush_range(__pa(ptr), __pa(ptr) + size); + __dma_clear_buffer(page, size); return page; } @@ -170,6 +268,9 @@ static int __init consistent_init(void) unsigned long base = consistent_base; unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT; + if (IS_ENABLED(CONFIG_CMA) && !IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) + return 0; + consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL); if (!consistent_pte) { pr_err("%s: no memory\n", __func__); @@ -184,14 +285,14 @@ static int __init consistent_init(void) pud = pud_alloc(&init_mm, pgd, base); if (!pud) { - printk(KERN_ERR "%s: no pud tables\n", __func__); + pr_err("%s: no pud tables\n", __func__); ret = -ENOMEM; break; } pmd = pmd_alloc(&init_mm, pud, base); if (!pmd) { - printk(KERN_ERR "%s: no pmd tables\n", __func__); + pr_err("%s: no pmd tables\n", __func__); ret = -ENOMEM; break; } @@ -199,7 +300,7 @@ static int __init consistent_init(void) pte = pte_alloc_kernel(pmd, base); if (!pte) { - printk(KERN_ERR "%s: no pte tables\n", __func__); + pr_err("%s: no pte tables\n", __func__); ret = -ENOMEM; break; } @@ -210,9 +311,101 @@ static int __init consistent_init(void) return ret; } - core_initcall(consistent_init); +static void *__alloc_from_contiguous(struct device *dev, size_t size, + pgprot_t prot, struct page **ret_page); + +static struct arm_vmregion_head coherent_head = { + .vm_lock = __SPIN_LOCK_UNLOCKED(&coherent_head.vm_lock), + .vm_list = LIST_HEAD_INIT(coherent_head.vm_list), +}; + +size_t coherent_pool_size = DEFAULT_CONSISTENT_DMA_SIZE / 8; + +static int __init early_coherent_pool(char *p) +{ + coherent_pool_size = memparse(p, &p); + return 0; +} +early_param("coherent_pool", early_coherent_pool); + +/* + * Initialise the coherent pool for atomic allocations. + */ +static int __init coherent_init(void) +{ + pgprot_t prot = pgprot_dmacoherent(pgprot_kernel); + size_t size = coherent_pool_size; + struct page *page; + void *ptr; + + if (!IS_ENABLED(CONFIG_CMA)) + return 0; + + ptr = __alloc_from_contiguous(NULL, size, prot, &page); + if (ptr) { + coherent_head.vm_start = (unsigned long) ptr; + coherent_head.vm_end = (unsigned long) ptr + size; + printk(KERN_INFO "DMA: preallocated %u KiB pool for atomic coherent allocations\n", + (unsigned)size / 1024); + return 0; + } + printk(KERN_ERR "DMA: failed to allocate %u KiB pool for atomic coherent allocation\n", + (unsigned)size / 1024); + return -ENOMEM; +} +/* + * CMA is activated by core_initcall, so we must be called after it. + */ +postcore_initcall(coherent_init); + +struct dma_contig_early_reserve { + phys_addr_t base; + unsigned long size; +}; + +static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata; + +static int dma_mmu_remap_num __initdata; + +void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) +{ + dma_mmu_remap[dma_mmu_remap_num].base = base; + dma_mmu_remap[dma_mmu_remap_num].size = size; + dma_mmu_remap_num++; +} + +void __init dma_contiguous_remap(void) +{ + int i; + for (i = 0; i < dma_mmu_remap_num; i++) { + phys_addr_t start = dma_mmu_remap[i].base; + phys_addr_t end = start + dma_mmu_remap[i].size; + struct map_desc map; + unsigned long addr; + + if (end > arm_lowmem_limit) + end = arm_lowmem_limit; + if (start >= end) + return; + + map.pfn = __phys_to_pfn(start); + map.virtual = __phys_to_virt(start); + map.length = end - start; + map.type = MT_MEMORY_DMA_READY; + + /* + * Clear previous low-memory mapping + */ + for (addr = __phys_to_virt(start); addr < __phys_to_virt(end); + addr += PMD_SIZE) + pmd_clear(pmd_off_k(addr)); + + iotable_init(&map, 1); + } +} + static void * __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, const void *caller) @@ -222,7 +415,7 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, int bit; if (!consistent_pte) { - printk(KERN_ERR "%s: not initialised\n", __func__); + pr_err("%s: not initialised\n", __func__); dump_stack(); return NULL; } @@ -249,7 +442,7 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); pte = consistent_pte[idx] + off; - c->vm_pages = page; + c->priv = page; do { BUG_ON(!pte_none(*pte)); @@ -281,14 +474,14 @@ static void __dma_free_remap(void *cpu_addr, size_t size) c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr); if (!c) { - printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", + pr_err("%s: trying to free invalid coherent area: %p\n", __func__, cpu_addr); dump_stack(); return; } if ((c->vm_end - c->vm_start) != size) { - printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", + pr_err("%s: freeing wrong coherent size (%ld != %d)\n", __func__, c->vm_end - c->vm_start, size); dump_stack(); size = c->vm_end - c->vm_start; @@ -310,8 +503,8 @@ static void __dma_free_remap(void *cpu_addr, size_t size) } if (pte_none(pte) || !pte_present(pte)) - printk(KERN_CRIT "%s: bad page in kernel page table\n", - __func__); + pr_crit("%s: bad page in kernel page table\n", + __func__); } while (size -= PAGE_SIZE); flush_tlb_kernel_range(c->vm_start, c->vm_end); @@ -319,20 +512,182 @@ static void __dma_free_remap(void *cpu_addr, size_t size) arm_vmregion_free(&consistent_head, c); } +static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr, + void *data) +{ + struct page *page = virt_to_page(addr); + pgprot_t prot = *(pgprot_t *)data; + + set_pte_ext(pte, mk_pte(page, prot), 0); + return 0; +} + +static void __dma_remap(struct page *page, size_t size, pgprot_t prot) +{ + unsigned long start = (unsigned long) page_address(page); + unsigned end = start + size; + + apply_to_page_range(&init_mm, start, size, __dma_update_pte, &prot); + dsb(); + flush_tlb_kernel_range(start, end); +} + +static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, + pgprot_t prot, struct page **ret_page, + const void *caller) +{ + struct page *page; + void *ptr; + page = __dma_alloc_buffer(dev, size, gfp); + if (!page) + return NULL; + + ptr = __dma_alloc_remap(page, size, gfp, prot, caller); + if (!ptr) { + __dma_free_buffer(page, size); + return NULL; + } + + *ret_page = page; + return ptr; +} + +static void *__alloc_from_pool(struct device *dev, size_t size, + struct page **ret_page, const void *caller) +{ + struct arm_vmregion *c; + size_t align; + + if (!coherent_head.vm_start) { + printk(KERN_ERR "%s: coherent pool not initialised!\n", + __func__); + dump_stack(); + return NULL; + } + + /* + * Align the region allocation - allocations from pool are rather + * small, so align them to their order in pages, minimum is a page + * size. This helps reduce fragmentation of the DMA space. + */ + align = PAGE_SIZE << get_order(size); + c = arm_vmregion_alloc(&coherent_head, align, size, 0, caller); + if (c) { + void *ptr = (void *)c->vm_start; + struct page *page = virt_to_page(ptr); + *ret_page = page; + return ptr; + } + return NULL; +} + +static int __free_from_pool(void *cpu_addr, size_t size) +{ + unsigned long start = (unsigned long)cpu_addr; + unsigned long end = start + size; + struct arm_vmregion *c; + + if (start < coherent_head.vm_start || end > coherent_head.vm_end) + return 0; + + c = arm_vmregion_find_remove(&coherent_head, (unsigned long)start); + + if ((c->vm_end - c->vm_start) != size) { + printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", + __func__, c->vm_end - c->vm_start, size); + dump_stack(); + size = c->vm_end - c->vm_start; + } + + arm_vmregion_free(&coherent_head, c); + return 1; +} + +static void *__alloc_from_contiguous(struct device *dev, size_t size, + pgprot_t prot, struct page **ret_page) +{ + unsigned long order = get_order(size); + size_t count = size >> PAGE_SHIFT; + struct page *page; + + page = dma_alloc_from_contiguous(dev, count, order); + if (!page) + return NULL; + + __dma_clear_buffer(page, size); + __dma_remap(page, size, prot); + + *ret_page = page; + return page_address(page); +} + +static void __free_from_contiguous(struct device *dev, struct page *page, + size_t size) +{ + __dma_remap(page, size, pgprot_kernel); + dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT); +} + +static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot) +{ + prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ? + pgprot_writecombine(prot) : + pgprot_dmacoherent(prot); + return prot; +} + +#define nommu() 0 + #else /* !CONFIG_MMU */ -#define __dma_alloc_remap(page, size, gfp, prot, c) page_address(page) -#define __dma_free_remap(addr, size) do { } while (0) +#define nommu() 1 + +#define __get_dma_pgprot(attrs, prot) __pgprot(0) +#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL +#define __alloc_from_pool(dev, size, ret_page, c) NULL +#define __alloc_from_contiguous(dev, size, prot, ret) NULL +#define __free_from_pool(cpu_addr, size) 0 +#define __free_from_contiguous(dev, page, size) do { } while (0) +#define __dma_free_remap(cpu_addr, size) do { } while (0) #endif /* CONFIG_MMU */ -static void * -__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, - pgprot_t prot, const void *caller) +static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp, + struct page **ret_page) +{ + struct page *page; + page = __dma_alloc_buffer(dev, size, gfp); + if (!page) + return NULL; + + *ret_page = page; + return page_address(page); +} + + + +static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp, pgprot_t prot, const void *caller) { + u64 mask = get_coherent_dma_mask(dev); struct page *page; void *addr; +#ifdef CONFIG_DMA_API_DEBUG + u64 limit = (mask + 1) & ~mask; + if (limit && size >= limit) { + dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n", + size, mask); + return NULL; + } +#endif + + if (!mask) + return NULL; + + if (mask < 0xffffffffULL) + gfp |= GFP_DMA; + /* * Following is a work-around (a.k.a. hack) to prevent pages * with __GFP_COMP being passed to split_page() which cannot @@ -342,22 +697,20 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, */ gfp &= ~(__GFP_COMP); - *handle = ~0; + *handle = DMA_ERROR_CODE; size = PAGE_ALIGN(size); - page = __dma_alloc_buffer(dev, size, gfp); - if (!page) - return NULL; - - if (!arch_is_coherent()) - addr = __dma_alloc_remap(page, size, gfp, prot, caller); + if (arch_is_coherent() || nommu()) + addr = __alloc_simple_buffer(dev, size, gfp, &page); + else if (!IS_ENABLED(CONFIG_CMA)) + addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller); + else if (gfp & GFP_ATOMIC) + addr = __alloc_from_pool(dev, size, &page, caller); else - addr = page_address(page); + addr = __alloc_from_contiguous(dev, size, prot, &page); if (addr) *handle = pfn_to_dma(dev, page_to_pfn(page)); - else - __dma_free_buffer(page, size); return addr; } @@ -366,138 +719,71 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, * Allocate DMA-coherent memory space and return both the kernel remapped * virtual and bus address for that space. */ -void * -dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) +void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp, struct dma_attrs *attrs) { + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel); void *memory; if (dma_alloc_from_coherent(dev, size, handle, &memory)) return memory; - return __dma_alloc(dev, size, handle, gfp, - pgprot_dmacoherent(pgprot_kernel), + return __dma_alloc(dev, size, handle, gfp, prot, __builtin_return_address(0)); } -EXPORT_SYMBOL(dma_alloc_coherent); /* - * Allocate a writecombining region, in much the same way as - * dma_alloc_coherent above. + * Create userspace mapping for the DMA-coherent memory. */ -void * -dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) -{ - return __dma_alloc(dev, size, handle, gfp, - pgprot_writecombine(pgprot_kernel), - __builtin_return_address(0)); -} -EXPORT_SYMBOL(dma_alloc_writecombine); - -static int dma_mmap(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, size_t size) +int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + struct dma_attrs *attrs) { int ret = -ENXIO; #ifdef CONFIG_MMU - unsigned long user_size, kern_size; - struct arm_vmregion *c; + unsigned long pfn = dma_to_pfn(dev, dma_addr); + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); - user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) + return ret; - c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); - if (c) { - unsigned long off = vma->vm_pgoff; - - kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; - - if (off < kern_size && - user_size <= (kern_size - off)) { - ret = remap_pfn_range(vma, vma->vm_start, - page_to_pfn(c->vm_pages) + off, - user_size << PAGE_SHIFT, - vma->vm_page_prot); - } - } + ret = remap_pfn_range(vma, vma->vm_start, + pfn + vma->vm_pgoff, + vma->vm_end - vma->vm_start, + vma->vm_page_prot); #endif /* CONFIG_MMU */ return ret; } -int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, size_t size) -{ - vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot); - return dma_mmap(dev, vma, cpu_addr, dma_addr, size); -} -EXPORT_SYMBOL(dma_mmap_coherent); - -int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, size_t size) -{ - vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); - return dma_mmap(dev, vma, cpu_addr, dma_addr, size); -} -EXPORT_SYMBOL(dma_mmap_writecombine); - /* - * free a page as defined by the above mapping. - * Must not be called with IRQs disabled. + * Free a buffer as defined by the above mapping. */ -void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle) +void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs) { - WARN_ON(irqs_disabled()); + struct page *page = pfn_to_page(dma_to_pfn(dev, handle)); if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) return; size = PAGE_ALIGN(size); - if (!arch_is_coherent()) + if (arch_is_coherent() || nommu()) { + __dma_free_buffer(page, size); + } else if (!IS_ENABLED(CONFIG_CMA)) { __dma_free_remap(cpu_addr, size); - - __dma_free_buffer(pfn_to_page(dma_to_pfn(dev, handle)), size); -} -EXPORT_SYMBOL(dma_free_coherent); - -/* - * Make an area consistent for devices. - * Note: Drivers should NOT use this function directly, as it will break - * platforms with CONFIG_DMABOUNCE. - * Use the driver DMA support - see dma-mapping.h (dma_sync_*) - */ -void ___dma_single_cpu_to_dev(const void *kaddr, size_t size, - enum dma_data_direction dir) -{ - unsigned long paddr; - - BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1)); - - dmac_map_area(kaddr, size, dir); - - paddr = __pa(kaddr); - if (dir == DMA_FROM_DEVICE) { - outer_inv_range(paddr, paddr + size); + __dma_free_buffer(page, size); } else { - outer_clean_range(paddr, paddr + size); - } - /* FIXME: non-speculating: flush on bidirectional mappings? */ -} -EXPORT_SYMBOL(___dma_single_cpu_to_dev); - -void ___dma_single_dev_to_cpu(const void *kaddr, size_t size, - enum dma_data_direction dir) -{ - BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1)); - - /* FIXME: non-speculating: not required */ - /* don't bother invalidating if DMA to device */ - if (dir != DMA_TO_DEVICE) { - unsigned long paddr = __pa(kaddr); - outer_inv_range(paddr, paddr + size); + if (__free_from_pool(cpu_addr, size)) + return; + /* + * Non-atomic allocations cannot be freed with IRQs disabled + */ + WARN_ON(irqs_disabled()); + __free_from_contiguous(dev, page, size); } - - dmac_unmap_area(kaddr, size, dir); } -EXPORT_SYMBOL(___dma_single_dev_to_cpu); static void dma_cache_maint_page(struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir, @@ -543,7 +829,13 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, } while (left); } -void ___dma_page_cpu_to_dev(struct page *page, unsigned long off, +/* + * Make an area consistent for devices. + * Note: Drivers should NOT use this function directly, as it will break + * platforms with CONFIG_DMABOUNCE. + * Use the driver DMA support - see dma-mapping.h (dma_sync_*) + */ +static void __dma_page_cpu_to_dev(struct page *page, unsigned long off, size_t size, enum dma_data_direction dir) { unsigned long paddr; @@ -558,9 +850,8 @@ void ___dma_page_cpu_to_dev(struct page *page, unsigned long off, } /* FIXME: non-speculating: flush on bidirectional mappings? */ } -EXPORT_SYMBOL(___dma_page_cpu_to_dev); -void ___dma_page_dev_to_cpu(struct page *page, unsigned long off, +static void __dma_page_dev_to_cpu(struct page *page, unsigned long off, size_t size, enum dma_data_direction dir) { unsigned long paddr = page_to_phys(page) + off; @@ -578,10 +869,9 @@ void ___dma_page_dev_to_cpu(struct page *page, unsigned long off, if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE) set_bit(PG_dcache_clean, &page->flags); } -EXPORT_SYMBOL(___dma_page_dev_to_cpu); /** - * dma_map_sg - map a set of SG buffers for streaming mode DMA + * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices * @sg: list of buffers * @nents: number of buffers to map @@ -596,32 +886,32 @@ EXPORT_SYMBOL(___dma_page_dev_to_cpu); * Device ownership issues as mentioned for dma_map_single are the same * here. */ -int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction dir) +int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir, struct dma_attrs *attrs) { + struct dma_map_ops *ops = get_dma_ops(dev); struct scatterlist *s; int i, j; - BUG_ON(!valid_dma_direction(dir)); - for_each_sg(sg, s, nents, i) { - s->dma_address = __dma_map_page(dev, sg_page(s), s->offset, - s->length, dir); +#ifdef CONFIG_NEED_SG_DMA_LENGTH + s->dma_length = s->length; +#endif + s->dma_address = ops->map_page(dev, sg_page(s), s->offset, + s->length, dir, attrs); if (dma_mapping_error(dev, s->dma_address)) goto bad_mapping; } - debug_dma_map_sg(dev, sg, nents, nents, dir); return nents; bad_mapping: for_each_sg(sg, s, i, j) - __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir); + ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs); return 0; } -EXPORT_SYMBOL(dma_map_sg); /** - * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg + * arm_dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices * @sg: list of buffers * @nents: number of buffers to unmap (same as was passed to dma_map_sg) @@ -630,70 +920,55 @@ EXPORT_SYMBOL(dma_map_sg); * Unmap a set of streaming mode DMA translations. Again, CPU access * rules concerning calls here are the same as for dma_unmap_single(). */ -void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction dir) +void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir, struct dma_attrs *attrs) { + struct dma_map_ops *ops = get_dma_ops(dev); struct scatterlist *s; - int i; - debug_dma_unmap_sg(dev, sg, nents, dir); + int i; for_each_sg(sg, s, nents, i) - __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir); + ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs); } -EXPORT_SYMBOL(dma_unmap_sg); /** - * dma_sync_sg_for_cpu + * arm_dma_sync_sg_for_cpu * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices * @sg: list of buffers * @nents: number of buffers to map (returned from dma_map_sg) * @dir: DMA transfer direction (same as was passed to dma_map_sg) */ -void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, +void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir) { + struct dma_map_ops *ops = get_dma_ops(dev); struct scatterlist *s; int i; - for_each_sg(sg, s, nents, i) { - if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0, - sg_dma_len(s), dir)) - continue; - - __dma_page_dev_to_cpu(sg_page(s), s->offset, - s->length, dir); - } - - debug_dma_sync_sg_for_cpu(dev, sg, nents, dir); + for_each_sg(sg, s, nents, i) + ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length, + dir); } -EXPORT_SYMBOL(dma_sync_sg_for_cpu); /** - * dma_sync_sg_for_device + * arm_dma_sync_sg_for_device * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices * @sg: list of buffers * @nents: number of buffers to map (returned from dma_map_sg) * @dir: DMA transfer direction (same as was passed to dma_map_sg) */ -void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, +void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir) { + struct dma_map_ops *ops = get_dma_ops(dev); struct scatterlist *s; int i; - for_each_sg(sg, s, nents, i) { - if (!dmabounce_sync_for_device(dev, sg_dma_address(s), 0, - sg_dma_len(s), dir)) - continue; - - __dma_page_cpu_to_dev(sg_page(s), s->offset, - s->length, dir); - } - - debug_dma_sync_sg_for_device(dev, sg, nents, dir); + for_each_sg(sg, s, nents, i) + ops->sync_single_for_device(dev, sg_dma_address(s), s->length, + dir); } -EXPORT_SYMBOL(dma_sync_sg_for_device); /* * Return whether the given device DMA address mask can be supported @@ -709,18 +984,15 @@ int dma_supported(struct device *dev, u64 mask) } EXPORT_SYMBOL(dma_supported); -int dma_set_mask(struct device *dev, u64 dma_mask) +static int arm_dma_set_mask(struct device *dev, u64 dma_mask) { if (!dev->dma_mask || !dma_supported(dev, dma_mask)) return -EIO; -#ifndef CONFIG_DMABOUNCE *dev->dma_mask = dma_mask; -#endif return 0; } -EXPORT_SYMBOL(dma_set_mask); #define PREALLOC_DMA_DEBUG_ENTRIES 4096 @@ -733,3 +1005,679 @@ static int __init dma_debug_do_init(void) return 0; } fs_initcall(dma_debug_do_init); + +#ifdef CONFIG_ARM_DMA_USE_IOMMU + +/* IOMMU */ + +static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping, + size_t size) +{ + unsigned int order = get_order(size); + unsigned int align = 0; + unsigned int count, start; + unsigned long flags; + + count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) + + (1 << mapping->order) - 1) >> mapping->order; + + if (order > mapping->order) + align = (1 << (order - mapping->order)) - 1; + + spin_lock_irqsave(&mapping->lock, flags); + start = bitmap_find_next_zero_area(mapping->bitmap, mapping->bits, 0, + count, align); + if (start > mapping->bits) { + spin_unlock_irqrestore(&mapping->lock, flags); + return DMA_ERROR_CODE; + } + + bitmap_set(mapping->bitmap, start, count); + spin_unlock_irqrestore(&mapping->lock, flags); + + return mapping->base + (start << (mapping->order + PAGE_SHIFT)); +} + +static inline void __free_iova(struct dma_iommu_mapping *mapping, + dma_addr_t addr, size_t size) +{ + unsigned int start = (addr - mapping->base) >> + (mapping->order + PAGE_SHIFT); + unsigned int count = ((size >> PAGE_SHIFT) + + (1 << mapping->order) - 1) >> mapping->order; + unsigned long flags; + + spin_lock_irqsave(&mapping->lock, flags); + bitmap_clear(mapping->bitmap, start, count); + spin_unlock_irqrestore(&mapping->lock, flags); +} + +static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp) +{ + struct page **pages; + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int i = 0; + + if (array_size <= PAGE_SIZE) + pages = kzalloc(array_size, gfp); + else + pages = vzalloc(array_size); + if (!pages) + return NULL; + + while (count) { + int j, order = __ffs(count); + + pages[i] = alloc_pages(gfp | __GFP_NOWARN, order); + while (!pages[i] && order) + pages[i] = alloc_pages(gfp | __GFP_NOWARN, --order); + if (!pages[i]) + goto error; + + if (order) + split_page(pages[i], order); + j = 1 << order; + while (--j) + pages[i + j] = pages[i] + j; + + __dma_clear_buffer(pages[i], PAGE_SIZE << order); + i += 1 << order; + count -= 1 << order; + } + + return pages; +error: + while (--i) + if (pages[i]) + __free_pages(pages[i], 0); + if (array_size < PAGE_SIZE) + kfree(pages); + else + vfree(pages); + return NULL; +} + +static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t size) +{ + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int i; + for (i = 0; i < count; i++) + if (pages[i]) + __free_pages(pages[i], 0); + if (array_size < PAGE_SIZE) + kfree(pages); + else + vfree(pages); + return 0; +} + +/* + * Create a CPU mapping for a specified pages + */ +static void * +__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot) +{ + struct arm_vmregion *c; + size_t align; + size_t count = size >> PAGE_SHIFT; + int bit; + + if (!consistent_pte[0]) { + pr_err("%s: not initialised\n", __func__); + dump_stack(); + return NULL; + } + + /* + * Align the virtual region allocation - maximum alignment is + * a section size, minimum is a page size. This helps reduce + * fragmentation of the DMA space, and also prevents allocations + * smaller than a section from crossing a section boundary. + */ + bit = fls(size - 1); + if (bit > SECTION_SHIFT) + bit = SECTION_SHIFT; + align = 1 << bit; + + /* + * Allocate a virtual address in the consistent mapping region. + */ + c = arm_vmregion_alloc(&consistent_head, align, size, + gfp & ~(__GFP_DMA | __GFP_HIGHMEM), NULL); + if (c) { + pte_t *pte; + int idx = CONSISTENT_PTE_INDEX(c->vm_start); + int i = 0; + u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); + + pte = consistent_pte[idx] + off; + c->priv = pages; + + do { + BUG_ON(!pte_none(*pte)); + + set_pte_ext(pte, mk_pte(pages[i], prot), 0); + pte++; + off++; + i++; + if (off >= PTRS_PER_PTE) { + off = 0; + pte = consistent_pte[++idx]; + } + } while (i < count); + + dsb(); + + return (void *)c->vm_start; + } + return NULL; +} + +/* + * Create a mapping in device IO address space for specified pages + */ +static dma_addr_t +__iommu_create_mapping(struct device *dev, struct page **pages, size_t size) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + dma_addr_t dma_addr, iova; + int i, ret = DMA_ERROR_CODE; + + dma_addr = __alloc_iova(mapping, size); + if (dma_addr == DMA_ERROR_CODE) + return dma_addr; + + iova = dma_addr; + for (i = 0; i < count; ) { + unsigned int next_pfn = page_to_pfn(pages[i]) + 1; + phys_addr_t phys = page_to_phys(pages[i]); + unsigned int len, j; + + for (j = i + 1; j < count; j++, next_pfn++) + if (page_to_pfn(pages[j]) != next_pfn) + break; + + len = (j - i) << PAGE_SHIFT; + ret = iommu_map(mapping->domain, iova, phys, len, 0); + if (ret < 0) + goto fail; + iova += len; + i = j; + } + return dma_addr; +fail: + iommu_unmap(mapping->domain, dma_addr, iova-dma_addr); + __free_iova(mapping, dma_addr, size); + return DMA_ERROR_CODE; +} + +static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + + /* + * add optional in-page offset from iova to size and align + * result to page size + */ + size = PAGE_ALIGN((iova & ~PAGE_MASK) + size); + iova &= PAGE_MASK; + + iommu_unmap(mapping->domain, iova, size); + __free_iova(mapping, iova, size); + return 0; +} + +static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, + dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) +{ + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel); + struct page **pages; + void *addr = NULL; + + *handle = DMA_ERROR_CODE; + size = PAGE_ALIGN(size); + + pages = __iommu_alloc_buffer(dev, size, gfp); + if (!pages) + return NULL; + + *handle = __iommu_create_mapping(dev, pages, size); + if (*handle == DMA_ERROR_CODE) + goto err_buffer; + + addr = __iommu_alloc_remap(pages, size, gfp, prot); + if (!addr) + goto err_mapping; + + return addr; + +err_mapping: + __iommu_remove_mapping(dev, *handle, size); +err_buffer: + __iommu_free_buffer(dev, pages, size); + return NULL; +} + +static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + struct dma_attrs *attrs) +{ + struct arm_vmregion *c; + + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); + c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); + + if (c) { + struct page **pages = c->priv; + + unsigned long uaddr = vma->vm_start; + unsigned long usize = vma->vm_end - vma->vm_start; + int i = 0; + + do { + int ret; + + ret = vm_insert_page(vma, uaddr, pages[i++]); + if (ret) { + pr_err("Remapping memory, error: %d\n", ret); + return ret; + } + + uaddr += PAGE_SIZE; + usize -= PAGE_SIZE; + } while (usize > 0); + } + return 0; +} + +/* + * free a page as defined by the above mapping. + * Must not be called with IRQs disabled. + */ +void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs) +{ + struct arm_vmregion *c; + size = PAGE_ALIGN(size); + + c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); + if (c) { + struct page **pages = c->priv; + __dma_free_remap(cpu_addr, size); + __iommu_remove_mapping(dev, handle, size); + __iommu_free_buffer(dev, pages, size); + } +} + +/* + * Map a part of the scatter-gather list into contiguous io address space + */ +static int __map_sg_chunk(struct device *dev, struct scatterlist *sg, + size_t size, dma_addr_t *handle, + enum dma_data_direction dir) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + dma_addr_t iova, iova_base; + int ret = 0; + unsigned int count; + struct scatterlist *s; + + size = PAGE_ALIGN(size); + *handle = DMA_ERROR_CODE; + + iova_base = iova = __alloc_iova(mapping, size); + if (iova == DMA_ERROR_CODE) + return -ENOMEM; + + for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s)) { + phys_addr_t phys = page_to_phys(sg_page(s)); + unsigned int len = PAGE_ALIGN(s->offset + s->length); + + if (!arch_is_coherent()) + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); + + ret = iommu_map(mapping->domain, iova, phys, len, 0); + if (ret < 0) + goto fail; + count += len >> PAGE_SHIFT; + iova += len; + } + *handle = iova_base; + + return 0; +fail: + iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE); + __free_iova(mapping, iova_base, size); + return ret; +} + +/** + * arm_iommu_map_sg - map a set of SG buffers for streaming mode DMA + * @dev: valid struct device pointer + * @sg: list of buffers + * @nents: number of buffers to map + * @dir: DMA transfer direction + * + * Map a set of buffers described by scatterlist in streaming mode for DMA. + * The scatter gather list elements are merged together (if possible) and + * tagged with the appropriate dma address and length. They are obtained via + * sg_dma_{address,length}. + */ +int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + struct scatterlist *s = sg, *dma = sg, *start = sg; + int i, count = 0; + unsigned int offset = s->offset; + unsigned int size = s->offset + s->length; + unsigned int max = dma_get_max_seg_size(dev); + + for (i = 1; i < nents; i++) { + s = sg_next(s); + + s->dma_address = DMA_ERROR_CODE; + s->dma_length = 0; + + if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) { + if (__map_sg_chunk(dev, start, size, &dma->dma_address, + dir) < 0) + goto bad_mapping; + + dma->dma_address += offset; + dma->dma_length = size - offset; + + size = offset = s->offset; + start = s; + dma = sg_next(dma); + count += 1; + } + size += s->length; + } + if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0) + goto bad_mapping; + + dma->dma_address += offset; + dma->dma_length = size - offset; + + return count+1; + +bad_mapping: + for_each_sg(sg, s, count, i) + __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s)); + return 0; +} + +/** + * arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg + * @dev: valid struct device pointer + * @sg: list of buffers + * @nents: number of buffers to unmap (same as was passed to dma_map_sg) + * @dir: DMA transfer direction (same as was passed to dma_map_sg) + * + * Unmap a set of streaming mode DMA translations. Again, CPU access + * rules concerning calls here are the same as for dma_unmap_single(). + */ +void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) { + if (sg_dma_len(s)) + __iommu_remove_mapping(dev, sg_dma_address(s), + sg_dma_len(s)); + if (!arch_is_coherent()) + __dma_page_dev_to_cpu(sg_page(s), s->offset, + s->length, dir); + } +} + +/** + * arm_iommu_sync_sg_for_cpu + * @dev: valid struct device pointer + * @sg: list of buffers + * @nents: number of buffers to map (returned from dma_map_sg) + * @dir: DMA transfer direction (same as was passed to dma_map_sg) + */ +void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) + if (!arch_is_coherent()) + __dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir); + +} + +/** + * arm_iommu_sync_sg_for_device + * @dev: valid struct device pointer + * @sg: list of buffers + * @nents: number of buffers to map (returned from dma_map_sg) + * @dir: DMA transfer direction (same as was passed to dma_map_sg) + */ +void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) + if (!arch_is_coherent()) + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); +} + + +/** + * arm_iommu_map_page + * @dev: valid struct device pointer + * @page: page that buffer resides in + * @offset: offset into page for start of buffer + * @size: size of buffer to map + * @dir: DMA transfer direction + * + * IOMMU aware version of arm_dma_map_page() + */ +static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + dma_addr_t dma_addr; + int ret, len = PAGE_ALIGN(size + offset); + + if (!arch_is_coherent()) + __dma_page_cpu_to_dev(page, offset, size, dir); + + dma_addr = __alloc_iova(mapping, len); + if (dma_addr == DMA_ERROR_CODE) + return dma_addr; + + ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0); + if (ret < 0) + goto fail; + + return dma_addr + offset; +fail: + __free_iova(mapping, dma_addr, len); + return DMA_ERROR_CODE; +} + +/** + * arm_iommu_unmap_page + * @dev: valid struct device pointer + * @handle: DMA address of buffer + * @size: size of buffer (same as passed to dma_map_page) + * @dir: DMA transfer direction (same as passed to dma_map_page) + * + * IOMMU aware version of arm_dma_unmap_page() + */ +static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + dma_addr_t iova = handle & PAGE_MASK; + struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); + int offset = handle & ~PAGE_MASK; + int len = PAGE_ALIGN(size + offset); + + if (!iova) + return; + + if (!arch_is_coherent()) + __dma_page_dev_to_cpu(page, offset, size, dir); + + iommu_unmap(mapping->domain, iova, len); + __free_iova(mapping, iova, len); +} + +static void arm_iommu_sync_single_for_cpu(struct device *dev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + dma_addr_t iova = handle & PAGE_MASK; + struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); + unsigned int offset = handle & ~PAGE_MASK; + + if (!iova) + return; + + if (!arch_is_coherent()) + __dma_page_dev_to_cpu(page, offset, size, dir); +} + +static void arm_iommu_sync_single_for_device(struct device *dev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + dma_addr_t iova = handle & PAGE_MASK; + struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); + unsigned int offset = handle & ~PAGE_MASK; + + if (!iova) + return; + + __dma_page_cpu_to_dev(page, offset, size, dir); +} + +struct dma_map_ops iommu_ops = { + .alloc = arm_iommu_alloc_attrs, + .free = arm_iommu_free_attrs, + .mmap = arm_iommu_mmap_attrs, + + .map_page = arm_iommu_map_page, + .unmap_page = arm_iommu_unmap_page, + .sync_single_for_cpu = arm_iommu_sync_single_for_cpu, + .sync_single_for_device = arm_iommu_sync_single_for_device, + + .map_sg = arm_iommu_map_sg, + .unmap_sg = arm_iommu_unmap_sg, + .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu, + .sync_sg_for_device = arm_iommu_sync_sg_for_device, +}; + +/** + * arm_iommu_create_mapping + * @bus: pointer to the bus holding the client device (for IOMMU calls) + * @base: start address of the valid IO address space + * @size: size of the valid IO address space + * @order: accuracy of the IO addresses allocations + * + * Creates a mapping structure which holds information about used/unused + * IO address ranges, which is required to perform memory allocation and + * mapping with IOMMU aware functions. + * + * The client device need to be attached to the mapping with + * arm_iommu_attach_device function. + */ +struct dma_iommu_mapping * +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size, + int order) +{ + unsigned int count = size >> (PAGE_SHIFT + order); + unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long); + struct dma_iommu_mapping *mapping; + int err = -ENOMEM; + + if (!count) + return ERR_PTR(-EINVAL); + + mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL); + if (!mapping) + goto err; + + mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL); + if (!mapping->bitmap) + goto err2; + + mapping->base = base; + mapping->bits = BITS_PER_BYTE * bitmap_size; + mapping->order = order; + spin_lock_init(&mapping->lock); + + mapping->domain = iommu_domain_alloc(bus); + if (!mapping->domain) + goto err3; + + kref_init(&mapping->kref); + return mapping; +err3: + kfree(mapping->bitmap); +err2: + kfree(mapping); +err: + return ERR_PTR(err); +} + +static void release_iommu_mapping(struct kref *kref) +{ + struct dma_iommu_mapping *mapping = + container_of(kref, struct dma_iommu_mapping, kref); + + iommu_domain_free(mapping->domain); + kfree(mapping->bitmap); + kfree(mapping); +} + +void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping) +{ + if (mapping) + kref_put(&mapping->kref, release_iommu_mapping); +} + +/** + * arm_iommu_attach_device + * @dev: valid struct device pointer + * @mapping: io address space mapping structure (returned from + * arm_iommu_create_mapping) + * + * Attaches specified io address space mapping to the provided device, + * this replaces the dma operations (dma_map_ops pointer) with the + * IOMMU aware version. More than one client might be attached to + * the same io address space mapping. + */ +int arm_iommu_attach_device(struct device *dev, + struct dma_iommu_mapping *mapping) +{ + int err; + + err = iommu_attach_device(mapping->domain, dev); + if (err) + return err; + + kref_get(&mapping->kref); + dev->archdata.mapping = mapping; + set_dma_ops(dev, &iommu_ops); + + pr_info("Attached IOMMU controller to %s device.\n", dev_name(dev)); + return 0; +} + +#endif |