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Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 1832 |
1 files changed, 1832 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c new file mode 100644 index 000000000..d7909091c --- /dev/null +++ b/arch/arm/mm/dma-mapping.c @@ -0,0 +1,1832 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/mm/dma-mapping.c + * + * Copyright (C) 2000-2004 Russell King + * + * DMA uncached mapping support. + */ +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/genalloc.h> +#include <linux/gfp.h> +#include <linux/errno.h> +#include <linux/list.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/dma-direct.h> +#include <linux/dma-map-ops.h> +#include <linux/highmem.h> +#include <linux/memblock.h> +#include <linux/slab.h> +#include <linux/iommu.h> +#include <linux/io.h> +#include <linux/vmalloc.h> +#include <linux/sizes.h> +#include <linux/cma.h> + +#include <asm/memory.h> +#include <asm/highmem.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/mach/arch.h> +#include <asm/dma-iommu.h> +#include <asm/mach/map.h> +#include <asm/system_info.h> +#include <asm/xen/xen-ops.h> + +#include "dma.h" +#include "mm.h" + +struct arm_dma_alloc_args { + struct device *dev; + size_t size; + gfp_t gfp; + pgprot_t prot; + const void *caller; + bool want_vaddr; + int coherent_flag; +}; + +struct arm_dma_free_args { + struct device *dev; + size_t size; + void *cpu_addr; + struct page *page; + bool want_vaddr; +}; + +#define NORMAL 0 +#define COHERENT 1 + +struct arm_dma_allocator { + void *(*alloc)(struct arm_dma_alloc_args *args, + struct page **ret_page); + void (*free)(struct arm_dma_free_args *args); +}; + +struct arm_dma_buffer { + struct list_head list; + void *virt; + struct arm_dma_allocator *allocator; +}; + +static LIST_HEAD(arm_dma_bufs); +static DEFINE_SPINLOCK(arm_dma_bufs_lock); + +static struct arm_dma_buffer *arm_dma_buffer_find(void *virt) +{ + struct arm_dma_buffer *buf, *found = NULL; + unsigned long flags; + + spin_lock_irqsave(&arm_dma_bufs_lock, flags); + list_for_each_entry(buf, &arm_dma_bufs, list) { + if (buf->virt == virt) { + list_del(&buf->list); + found = buf; + break; + } + } + spin_unlock_irqrestore(&arm_dma_bufs_lock, flags); + return found; +} + +/* + * 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_clear_buffer(struct page *page, size_t size, int coherent_flag) +{ + /* + * Ensure that the allocated pages are zeroed, and that any data + * lurking in the kernel direct-mapped region is invalidated. + */ + if (PageHighMem(page)) { + phys_addr_t base = __pfn_to_phys(page_to_pfn(page)); + phys_addr_t end = base + size; + while (size > 0) { + void *ptr = kmap_atomic(page); + memset(ptr, 0, PAGE_SIZE); + if (coherent_flag != COHERENT) + dmac_flush_range(ptr, ptr + PAGE_SIZE); + kunmap_atomic(ptr); + page++; + size -= PAGE_SIZE; + } + if (coherent_flag != COHERENT) + outer_flush_range(base, end); + } else { + void *ptr = page_address(page); + memset(ptr, 0, size); + if (coherent_flag != COHERENT) { + 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. + */ +static struct page *__dma_alloc_buffer(struct device *dev, size_t size, + gfp_t gfp, int coherent_flag) +{ + unsigned long order = get_order(size); + struct page *page, *p, *e; + + page = alloc_pages(gfp, order); + if (!page) + return NULL; + + /* + * Now split the huge page and free the excess pages + */ + split_page(page, order); + for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++) + __free_page(p); + + __dma_clear_buffer(page, size, coherent_flag); + + return page; +} + +/* + * Free a DMA buffer. 'size' must be page aligned. + */ +static void __dma_free_buffer(struct page *page, size_t size) +{ + struct page *e = page + (size >> PAGE_SHIFT); + + while (page < e) { + __free_page(page); + page++; + } +} + +static void *__alloc_from_contiguous(struct device *dev, size_t size, + pgprot_t prot, struct page **ret_page, + const void *caller, bool want_vaddr, + int coherent_flag, gfp_t gfp); + +static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, + pgprot_t prot, struct page **ret_page, + const void *caller, bool want_vaddr); + +#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K +static struct gen_pool *atomic_pool __ro_after_init; + +static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE; + +static int __init early_coherent_pool(char *p) +{ + atomic_pool_size = memparse(p, &p); + return 0; +} +early_param("coherent_pool", early_coherent_pool); + +/* + * Initialise the coherent pool for atomic allocations. + */ +static int __init atomic_pool_init(void) +{ + pgprot_t prot = pgprot_dmacoherent(PAGE_KERNEL); + gfp_t gfp = GFP_KERNEL | GFP_DMA; + struct page *page; + void *ptr; + + atomic_pool = gen_pool_create(PAGE_SHIFT, -1); + if (!atomic_pool) + goto out; + /* + * The atomic pool is only used for non-coherent allocations + * so we must pass NORMAL for coherent_flag. + */ + if (dev_get_cma_area(NULL)) + ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot, + &page, atomic_pool_init, true, NORMAL, + GFP_KERNEL); + else + ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot, + &page, atomic_pool_init, true); + if (ptr) { + int ret; + + ret = gen_pool_add_virt(atomic_pool, (unsigned long)ptr, + page_to_phys(page), + atomic_pool_size, -1); + if (ret) + goto destroy_genpool; + + gen_pool_set_algo(atomic_pool, + gen_pool_first_fit_order_align, + NULL); + pr_info("DMA: preallocated %zu KiB pool for atomic coherent allocations\n", + atomic_pool_size / 1024); + return 0; + } + +destroy_genpool: + gen_pool_destroy(atomic_pool); + atomic_pool = NULL; +out: + pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n", + atomic_pool_size / 1024); + return -ENOMEM; +} +/* + * CMA is activated by core_initcall, so we must be called after it. + */ +postcore_initcall(atomic_pool_init); + +#ifdef CONFIG_CMA_AREAS +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) + continue; + + 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 to ensure that the + * TLB does not see any conflicting entries, then flush + * the TLB of the old entries before creating new mappings. + * + * This ensures that any speculatively loaded TLB entries + * (even though they may be rare) can not cause any problems, + * and ensures that this code is architecturally compliant. + */ + for (addr = __phys_to_virt(start); addr < __phys_to_virt(end); + addr += PMD_SIZE) + pmd_clear(pmd_off_k(addr)); + + flush_tlb_kernel_range(__phys_to_virt(start), + __phys_to_virt(end)); + + iotable_init(&map, 1); + } +} +#endif + +static int __dma_update_pte(pte_t *pte, unsigned long addr, void *data) +{ + struct page *page = virt_to_page((void *)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); + 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, bool want_vaddr) +{ + struct page *page; + void *ptr = NULL; + /* + * __alloc_remap_buffer is only called when the device is + * non-coherent + */ + page = __dma_alloc_buffer(dev, size, gfp, NORMAL); + if (!page) + return NULL; + if (!want_vaddr) + goto out; + + ptr = dma_common_contiguous_remap(page, size, prot, caller); + if (!ptr) { + __dma_free_buffer(page, size); + return NULL; + } + + out: + *ret_page = page; + return ptr; +} + +static void *__alloc_from_pool(size_t size, struct page **ret_page) +{ + unsigned long val; + void *ptr = NULL; + + if (!atomic_pool) { + WARN(1, "coherent pool not initialised!\n"); + return NULL; + } + + val = gen_pool_alloc(atomic_pool, size); + if (val) { + phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val); + + *ret_page = phys_to_page(phys); + ptr = (void *)val; + } + + return ptr; +} + +static bool __in_atomic_pool(void *start, size_t size) +{ + return gen_pool_has_addr(atomic_pool, (unsigned long)start, size); +} + +static int __free_from_pool(void *start, size_t size) +{ + if (!__in_atomic_pool(start, size)) + return 0; + + gen_pool_free(atomic_pool, (unsigned long)start, size); + + return 1; +} + +static void *__alloc_from_contiguous(struct device *dev, size_t size, + pgprot_t prot, struct page **ret_page, + const void *caller, bool want_vaddr, + int coherent_flag, gfp_t gfp) +{ + unsigned long order = get_order(size); + size_t count = size >> PAGE_SHIFT; + struct page *page; + void *ptr = NULL; + + page = dma_alloc_from_contiguous(dev, count, order, gfp & __GFP_NOWARN); + if (!page) + return NULL; + + __dma_clear_buffer(page, size, coherent_flag); + + if (!want_vaddr) + goto out; + + if (PageHighMem(page)) { + ptr = dma_common_contiguous_remap(page, size, prot, caller); + if (!ptr) { + dma_release_from_contiguous(dev, page, count); + return NULL; + } + } else { + __dma_remap(page, size, prot); + ptr = page_address(page); + } + + out: + *ret_page = page; + return ptr; +} + +static void __free_from_contiguous(struct device *dev, struct page *page, + void *cpu_addr, size_t size, bool want_vaddr) +{ + if (want_vaddr) { + if (PageHighMem(page)) + dma_common_free_remap(cpu_addr, size); + else + __dma_remap(page, size, PAGE_KERNEL); + } + dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT); +} + +static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot) +{ + prot = (attrs & DMA_ATTR_WRITE_COMBINE) ? + pgprot_writecombine(prot) : + pgprot_dmacoherent(prot); + return prot; +} + +static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp, + struct page **ret_page) +{ + struct page *page; + /* __alloc_simple_buffer is only called when the device is coherent */ + page = __dma_alloc_buffer(dev, size, gfp, COHERENT); + if (!page) + return NULL; + + *ret_page = page; + return page_address(page); +} + +static void *simple_allocator_alloc(struct arm_dma_alloc_args *args, + struct page **ret_page) +{ + return __alloc_simple_buffer(args->dev, args->size, args->gfp, + ret_page); +} + +static void simple_allocator_free(struct arm_dma_free_args *args) +{ + __dma_free_buffer(args->page, args->size); +} + +static struct arm_dma_allocator simple_allocator = { + .alloc = simple_allocator_alloc, + .free = simple_allocator_free, +}; + +static void *cma_allocator_alloc(struct arm_dma_alloc_args *args, + struct page **ret_page) +{ + return __alloc_from_contiguous(args->dev, args->size, args->prot, + ret_page, args->caller, + args->want_vaddr, args->coherent_flag, + args->gfp); +} + +static void cma_allocator_free(struct arm_dma_free_args *args) +{ + __free_from_contiguous(args->dev, args->page, args->cpu_addr, + args->size, args->want_vaddr); +} + +static struct arm_dma_allocator cma_allocator = { + .alloc = cma_allocator_alloc, + .free = cma_allocator_free, +}; + +static void *pool_allocator_alloc(struct arm_dma_alloc_args *args, + struct page **ret_page) +{ + return __alloc_from_pool(args->size, ret_page); +} + +static void pool_allocator_free(struct arm_dma_free_args *args) +{ + __free_from_pool(args->cpu_addr, args->size); +} + +static struct arm_dma_allocator pool_allocator = { + .alloc = pool_allocator_alloc, + .free = pool_allocator_free, +}; + +static void *remap_allocator_alloc(struct arm_dma_alloc_args *args, + struct page **ret_page) +{ + return __alloc_remap_buffer(args->dev, args->size, args->gfp, + args->prot, ret_page, args->caller, + args->want_vaddr); +} + +static void remap_allocator_free(struct arm_dma_free_args *args) +{ + if (args->want_vaddr) + dma_common_free_remap(args->cpu_addr, args->size); + + __dma_free_buffer(args->page, args->size); +} + +static struct arm_dma_allocator remap_allocator = { + .alloc = remap_allocator_alloc, + .free = remap_allocator_free, +}; + +static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp, pgprot_t prot, bool is_coherent, + unsigned long attrs, const void *caller) +{ + u64 mask = min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit); + struct page *page = NULL; + void *addr; + bool allowblock, cma; + struct arm_dma_buffer *buf; + struct arm_dma_alloc_args args = { + .dev = dev, + .size = PAGE_ALIGN(size), + .gfp = gfp, + .prot = prot, + .caller = caller, + .want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0), + .coherent_flag = is_coherent ? COHERENT : NORMAL, + }; + +#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 + + buf = kzalloc(sizeof(*buf), + gfp & ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)); + if (!buf) + 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 + * handle them. The real problem is that this flag probably + * should be 0 on ARM as it is not supported on this + * platform; see CONFIG_HUGETLBFS. + */ + gfp &= ~(__GFP_COMP); + args.gfp = gfp; + + *handle = DMA_MAPPING_ERROR; + allowblock = gfpflags_allow_blocking(gfp); + cma = allowblock ? dev_get_cma_area(dev) : NULL; + + if (cma) + buf->allocator = &cma_allocator; + else if (is_coherent) + buf->allocator = &simple_allocator; + else if (allowblock) + buf->allocator = &remap_allocator; + else + buf->allocator = &pool_allocator; + + addr = buf->allocator->alloc(&args, &page); + + if (page) { + unsigned long flags; + + *handle = phys_to_dma(dev, page_to_phys(page)); + buf->virt = args.want_vaddr ? addr : page; + + spin_lock_irqsave(&arm_dma_bufs_lock, flags); + list_add(&buf->list, &arm_dma_bufs); + spin_unlock_irqrestore(&arm_dma_bufs_lock, flags); + } else { + kfree(buf); + } + + return args.want_vaddr ? addr : page; +} + +/* + * Free a buffer as defined by the above mapping. + */ +static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, unsigned long attrs, + bool is_coherent) +{ + struct page *page = phys_to_page(dma_to_phys(dev, handle)); + struct arm_dma_buffer *buf; + struct arm_dma_free_args args = { + .dev = dev, + .size = PAGE_ALIGN(size), + .cpu_addr = cpu_addr, + .page = page, + .want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0), + }; + + buf = arm_dma_buffer_find(cpu_addr); + if (WARN(!buf, "Freeing invalid buffer %p\n", cpu_addr)) + return; + + buf->allocator->free(&args); + kfree(buf); +} + +static void dma_cache_maint_page(struct page *page, unsigned long offset, + size_t size, enum dma_data_direction dir, + void (*op)(const void *, size_t, int)) +{ + unsigned long pfn; + size_t left = size; + + pfn = page_to_pfn(page) + offset / PAGE_SIZE; + offset %= PAGE_SIZE; + + /* + * A single sg entry may refer to multiple physically contiguous + * pages. But we still need to process highmem pages individually. + * If highmem is not configured then the bulk of this loop gets + * optimized out. + */ + do { + size_t len = left; + void *vaddr; + + page = pfn_to_page(pfn); + + if (PageHighMem(page)) { + if (len + offset > PAGE_SIZE) + len = PAGE_SIZE - offset; + + if (cache_is_vipt_nonaliasing()) { + vaddr = kmap_atomic(page); + op(vaddr + offset, len, dir); + kunmap_atomic(vaddr); + } else { + vaddr = kmap_high_get(page); + if (vaddr) { + op(vaddr + offset, len, dir); + kunmap_high(page); + } + } + } else { + vaddr = page_address(page) + offset; + op(vaddr, len, dir); + } + offset = 0; + pfn++; + left -= len; + } while (left); +} + +/* + * Make an area consistent for devices. + * Note: Drivers should NOT use this function directly. + * 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) +{ + phys_addr_t paddr; + + dma_cache_maint_page(page, off, size, dir, dmac_map_area); + + paddr = page_to_phys(page) + off; + if (dir == DMA_FROM_DEVICE) { + outer_inv_range(paddr, paddr + size); + } else { + outer_clean_range(paddr, paddr + size); + } + /* FIXME: non-speculating: flush on bidirectional mappings? */ +} + +static void __dma_page_dev_to_cpu(struct page *page, unsigned long off, + size_t size, enum dma_data_direction dir) +{ + phys_addr_t paddr = page_to_phys(page) + off; + + /* FIXME: non-speculating: not required */ + /* in any case, don't bother invalidating if DMA to device */ + if (dir != DMA_TO_DEVICE) { + outer_inv_range(paddr, paddr + size); + + dma_cache_maint_page(page, off, size, dir, dmac_unmap_area); + } + + /* + * Mark the D-cache clean for these pages to avoid extra flushing. + */ + if (dir != DMA_TO_DEVICE && size >= PAGE_SIZE) { + unsigned long pfn; + size_t left = size; + + pfn = page_to_pfn(page) + off / PAGE_SIZE; + off %= PAGE_SIZE; + if (off) { + pfn++; + left -= PAGE_SIZE - off; + } + while (left >= PAGE_SIZE) { + page = pfn_to_page(pfn++); + set_bit(PG_dcache_clean, &page->flags); + left -= PAGE_SIZE; + } + } +} + +#ifdef CONFIG_ARM_DMA_USE_IOMMU + +static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs) +{ + int prot = 0; + + if (attrs & DMA_ATTR_PRIVILEGED) + prot |= IOMMU_PRIV; + + switch (dir) { + case DMA_BIDIRECTIONAL: + return prot | IOMMU_READ | IOMMU_WRITE; + case DMA_TO_DEVICE: + return prot | IOMMU_READ; + case DMA_FROM_DEVICE: + return prot | IOMMU_WRITE; + default: + return prot; + } +} + +/* IOMMU */ + +static int extend_iommu_mapping(struct dma_iommu_mapping *mapping); + +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; + size_t mapping_size = mapping->bits << PAGE_SHIFT; + unsigned long flags; + dma_addr_t iova; + int i; + + if (order > CONFIG_ARM_DMA_IOMMU_ALIGNMENT) + order = CONFIG_ARM_DMA_IOMMU_ALIGNMENT; + + count = PAGE_ALIGN(size) >> PAGE_SHIFT; + align = (1 << order) - 1; + + spin_lock_irqsave(&mapping->lock, flags); + for (i = 0; i < mapping->nr_bitmaps; i++) { + start = bitmap_find_next_zero_area(mapping->bitmaps[i], + mapping->bits, 0, count, align); + + if (start > mapping->bits) + continue; + + bitmap_set(mapping->bitmaps[i], start, count); + break; + } + + /* + * No unused range found. Try to extend the existing mapping + * and perform a second attempt to reserve an IO virtual + * address range of size bytes. + */ + if (i == mapping->nr_bitmaps) { + if (extend_iommu_mapping(mapping)) { + spin_unlock_irqrestore(&mapping->lock, flags); + return DMA_MAPPING_ERROR; + } + + start = bitmap_find_next_zero_area(mapping->bitmaps[i], + mapping->bits, 0, count, align); + + if (start > mapping->bits) { + spin_unlock_irqrestore(&mapping->lock, flags); + return DMA_MAPPING_ERROR; + } + + bitmap_set(mapping->bitmaps[i], start, count); + } + spin_unlock_irqrestore(&mapping->lock, flags); + + iova = mapping->base + (mapping_size * i); + iova += start << PAGE_SHIFT; + + return iova; +} + +static inline void __free_iova(struct dma_iommu_mapping *mapping, + dma_addr_t addr, size_t size) +{ + unsigned int start, count; + size_t mapping_size = mapping->bits << PAGE_SHIFT; + unsigned long flags; + dma_addr_t bitmap_base; + u32 bitmap_index; + + if (!size) + return; + + bitmap_index = (u32) (addr - mapping->base) / (u32) mapping_size; + BUG_ON(addr < mapping->base || bitmap_index > mapping->extensions); + + bitmap_base = mapping->base + mapping_size * bitmap_index; + + start = (addr - bitmap_base) >> PAGE_SHIFT; + + if (addr + size > bitmap_base + mapping_size) { + /* + * The address range to be freed reaches into the iova + * range of the next bitmap. This should not happen as + * we don't allow this in __alloc_iova (at the + * moment). + */ + BUG(); + } else + count = size >> PAGE_SHIFT; + + spin_lock_irqsave(&mapping->lock, flags); + bitmap_clear(mapping->bitmaps[bitmap_index], start, count); + spin_unlock_irqrestore(&mapping->lock, flags); +} + +/* We'll try 2M, 1M, 64K, and finally 4K; array must end with 0! */ +static const int iommu_order_array[] = { 9, 8, 4, 0 }; + +static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, + gfp_t gfp, unsigned long attrs, + int coherent_flag) +{ + struct page **pages; + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int i = 0; + int order_idx = 0; + + if (array_size <= PAGE_SIZE) + pages = kzalloc(array_size, GFP_KERNEL); + else + pages = vzalloc(array_size); + if (!pages) + return NULL; + + if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) + { + unsigned long order = get_order(size); + struct page *page; + + page = dma_alloc_from_contiguous(dev, count, order, + gfp & __GFP_NOWARN); + if (!page) + goto error; + + __dma_clear_buffer(page, size, coherent_flag); + + for (i = 0; i < count; i++) + pages[i] = page + i; + + return pages; + } + + /* Go straight to 4K chunks if caller says it's OK. */ + if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES) + order_idx = ARRAY_SIZE(iommu_order_array) - 1; + + /* + * IOMMU can map any pages, so himem can also be used here + */ + gfp |= __GFP_NOWARN | __GFP_HIGHMEM; + + while (count) { + int j, order; + + order = iommu_order_array[order_idx]; + + /* Drop down when we get small */ + if (__fls(count) < order) { + order_idx++; + continue; + } + + if (order) { + /* See if it's easy to allocate a high-order chunk */ + pages[i] = alloc_pages(gfp | __GFP_NORETRY, order); + + /* Go down a notch at first sign of pressure */ + if (!pages[i]) { + order_idx++; + continue; + } + } else { + pages[i] = alloc_pages(gfp, 0); + 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, coherent_flag); + i += 1 << order; + count -= 1 << order; + } + + return pages; +error: + while (i--) + if (pages[i]) + __free_pages(pages[i], 0); + kvfree(pages); + return NULL; +} + +static int __iommu_free_buffer(struct device *dev, struct page **pages, + size_t size, unsigned long attrs) +{ + int count = size >> PAGE_SHIFT; + int i; + + if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { + dma_release_from_contiguous(dev, pages[0], count); + } else { + for (i = 0; i < count; i++) + if (pages[i]) + __free_pages(pages[i], 0); + } + + kvfree(pages); + return 0; +} + +/* + * 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, + unsigned long attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + dma_addr_t dma_addr, iova; + int i; + + dma_addr = __alloc_iova(mapping, size); + if (dma_addr == DMA_MAPPING_ERROR) + return dma_addr; + + iova = dma_addr; + for (i = 0; i < count; ) { + int ret; + + 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, + __dma_info_to_prot(DMA_BIDIRECTIONAL, attrs)); + 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_MAPPING_ERROR; +} + +static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + + /* + * 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 struct page **__atomic_get_pages(void *addr) +{ + struct page *page; + phys_addr_t phys; + + phys = gen_pool_virt_to_phys(atomic_pool, (unsigned long)addr); + page = phys_to_page(phys); + + return (struct page **)page; +} + +static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs) +{ + if (__in_atomic_pool(cpu_addr, PAGE_SIZE)) + return __atomic_get_pages(cpu_addr); + + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) + return cpu_addr; + + return dma_common_find_pages(cpu_addr); +} + +static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp, + dma_addr_t *handle, int coherent_flag, + unsigned long attrs) +{ + struct page *page; + void *addr; + + if (coherent_flag == COHERENT) + addr = __alloc_simple_buffer(dev, size, gfp, &page); + else + addr = __alloc_from_pool(size, &page); + if (!addr) + return NULL; + + *handle = __iommu_create_mapping(dev, &page, size, attrs); + if (*handle == DMA_MAPPING_ERROR) + goto err_mapping; + + return addr; + +err_mapping: + __free_from_pool(addr, size); + return NULL; +} + +static void __iommu_free_atomic(struct device *dev, void *cpu_addr, + dma_addr_t handle, size_t size, int coherent_flag) +{ + __iommu_remove_mapping(dev, handle, size); + if (coherent_flag == COHERENT) + __dma_free_buffer(virt_to_page(cpu_addr), size); + else + __free_from_pool(cpu_addr, size); +} + +static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, + dma_addr_t *handle, gfp_t gfp, unsigned long attrs) +{ + pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL); + struct page **pages; + void *addr = NULL; + int coherent_flag = dev->dma_coherent ? COHERENT : NORMAL; + + *handle = DMA_MAPPING_ERROR; + size = PAGE_ALIGN(size); + + if (coherent_flag == COHERENT || !gfpflags_allow_blocking(gfp)) + return __iommu_alloc_simple(dev, size, gfp, handle, + coherent_flag, attrs); + + /* + * Following is a work-around (a.k.a. hack) to prevent pages + * with __GFP_COMP being passed to split_page() which cannot + * handle them. The real problem is that this flag probably + * should be 0 on ARM as it is not supported on this + * platform; see CONFIG_HUGETLBFS. + */ + gfp &= ~(__GFP_COMP); + + pages = __iommu_alloc_buffer(dev, size, gfp, attrs, coherent_flag); + if (!pages) + return NULL; + + *handle = __iommu_create_mapping(dev, pages, size, attrs); + if (*handle == DMA_MAPPING_ERROR) + goto err_buffer; + + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) + return pages; + + addr = dma_common_pages_remap(pages, size, prot, + __builtin_return_address(0)); + if (!addr) + goto err_mapping; + + return addr; + +err_mapping: + __iommu_remove_mapping(dev, *handle, size); +err_buffer: + __iommu_free_buffer(dev, pages, size, attrs); + 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, + unsigned long attrs) +{ + struct page **pages = __iommu_get_pages(cpu_addr, attrs); + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; + int err; + + if (!pages) + return -ENXIO; + + if (vma->vm_pgoff >= nr_pages) + return -ENXIO; + + if (!dev->dma_coherent) + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); + + err = vm_map_pages(vma, pages, nr_pages); + if (err) + pr_err("Remapping memory failed: %d\n", err); + + return err; +} + +/* + * free a page as defined by the above mapping. + * Must not be called with IRQs disabled. + */ +static void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, unsigned long attrs) +{ + int coherent_flag = dev->dma_coherent ? COHERENT : NORMAL; + struct page **pages; + size = PAGE_ALIGN(size); + + if (coherent_flag == COHERENT || __in_atomic_pool(cpu_addr, size)) { + __iommu_free_atomic(dev, cpu_addr, handle, size, coherent_flag); + return; + } + + pages = __iommu_get_pages(cpu_addr, attrs); + if (!pages) { + WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); + return; + } + + if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0) + dma_common_free_remap(cpu_addr, size); + + __iommu_remove_mapping(dev, handle, size); + __iommu_free_buffer(dev, pages, size, attrs); +} + +static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt, + void *cpu_addr, dma_addr_t dma_addr, + size_t size, unsigned long attrs) +{ + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct page **pages = __iommu_get_pages(cpu_addr, attrs); + + if (!pages) + return -ENXIO; + + return sg_alloc_table_from_pages(sgt, pages, count, 0, size, + GFP_KERNEL); +} + +/* + * 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, unsigned long attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t iova, iova_base; + int ret = 0; + unsigned int count; + struct scatterlist *s; + int prot; + + size = PAGE_ALIGN(size); + *handle = DMA_MAPPING_ERROR; + + iova_base = iova = __alloc_iova(mapping, size); + if (iova == DMA_MAPPING_ERROR) + 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 (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); + + prot = __dma_info_to_prot(dir, attrs); + + ret = iommu_map(mapping->domain, iova, phys, len, prot); + 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}. + */ +static int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + struct scatterlist *s = sg, *dma = sg, *start = sg; + int i, count = 0, ret; + 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_length = 0; + + if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) { + ret = __map_sg_chunk(dev, start, size, + &dma->dma_address, dir, attrs); + if (ret < 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; + } + ret = __map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs); + if (ret < 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)); + if (ret == -ENOMEM) + return ret; + return -EINVAL; +} + +/** + * 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(). + */ +static void arm_iommu_unmap_sg(struct device *dev, + struct scatterlist *sg, int nents, + enum dma_data_direction dir, + unsigned long 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 (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __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) + */ +static 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; + + if (dev->dma_coherent) + return; + + for_each_sg(sg, s, nents, i) + __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) + */ +static 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; + + if (dev->dma_coherent) + return; + + for_each_sg(sg, s, nents, i) + __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, + unsigned long attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t dma_addr; + int ret, prot, len = PAGE_ALIGN(size + offset); + + if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_page_cpu_to_dev(page, offset, size, dir); + + dma_addr = __alloc_iova(mapping, len); + if (dma_addr == DMA_MAPPING_ERROR) + return dma_addr; + + prot = __dma_info_to_prot(dir, attrs); + + ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot); + if (ret < 0) + goto fail; + + return dma_addr + offset; +fail: + __free_iova(mapping, dma_addr, len); + return DMA_MAPPING_ERROR; +} + +/** + * 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, unsigned long attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t iova = handle & PAGE_MASK; + struct page *page; + int offset = handle & ~PAGE_MASK; + int len = PAGE_ALIGN(size + offset); + + if (!iova) + return; + + if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { + page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); + __dma_page_dev_to_cpu(page, offset, size, dir); + } + + iommu_unmap(mapping->domain, iova, len); + __free_iova(mapping, iova, len); +} + +/** + * arm_iommu_map_resource - map a device resource for DMA + * @dev: valid struct device pointer + * @phys_addr: physical address of resource + * @size: size of resource to map + * @dir: DMA transfer direction + */ +static dma_addr_t arm_iommu_map_resource(struct device *dev, + phys_addr_t phys_addr, size_t size, + enum dma_data_direction dir, unsigned long attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t dma_addr; + int ret, prot; + phys_addr_t addr = phys_addr & PAGE_MASK; + unsigned int offset = phys_addr & ~PAGE_MASK; + size_t len = PAGE_ALIGN(size + offset); + + dma_addr = __alloc_iova(mapping, len); + if (dma_addr == DMA_MAPPING_ERROR) + return dma_addr; + + prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO; + + ret = iommu_map(mapping->domain, dma_addr, addr, len, prot); + if (ret < 0) + goto fail; + + return dma_addr + offset; +fail: + __free_iova(mapping, dma_addr, len); + return DMA_MAPPING_ERROR; +} + +/** + * arm_iommu_unmap_resource - unmap a device DMA resource + * @dev: valid struct device pointer + * @dma_handle: DMA address to resource + * @size: size of resource to map + * @dir: DMA transfer direction + */ +static void arm_iommu_unmap_resource(struct device *dev, dma_addr_t dma_handle, + size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t iova = dma_handle & PAGE_MASK; + unsigned int offset = dma_handle & ~PAGE_MASK; + size_t len = PAGE_ALIGN(size + offset); + + if (!iova) + return; + + 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 = to_dma_iommu_mapping(dev); + dma_addr_t iova = handle & PAGE_MASK; + struct page *page; + unsigned int offset = handle & ~PAGE_MASK; + + if (dev->dma_coherent || !iova) + return; + + page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); + __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 = to_dma_iommu_mapping(dev); + dma_addr_t iova = handle & PAGE_MASK; + struct page *page; + unsigned int offset = handle & ~PAGE_MASK; + + if (dev->dma_coherent || !iova) + return; + + page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); + __dma_page_cpu_to_dev(page, offset, size, dir); +} + +static const struct dma_map_ops iommu_ops = { + .alloc = arm_iommu_alloc_attrs, + .free = arm_iommu_free_attrs, + .mmap = arm_iommu_mmap_attrs, + .get_sgtable = arm_iommu_get_sgtable, + + .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, + + .map_resource = arm_iommu_map_resource, + .unmap_resource = arm_iommu_unmap_resource, +}; + +/** + * 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: maximum size of the valid IO address space + * + * 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, u64 size) +{ + unsigned int bits = size >> PAGE_SHIFT; + unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long); + struct dma_iommu_mapping *mapping; + int extensions = 1; + int err = -ENOMEM; + + /* currently only 32-bit DMA address space is supported */ + if (size > DMA_BIT_MASK(32) + 1) + return ERR_PTR(-ERANGE); + + if (!bitmap_size) + return ERR_PTR(-EINVAL); + + if (bitmap_size > PAGE_SIZE) { + extensions = bitmap_size / PAGE_SIZE; + bitmap_size = PAGE_SIZE; + } + + mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL); + if (!mapping) + goto err; + + mapping->bitmap_size = bitmap_size; + mapping->bitmaps = kcalloc(extensions, sizeof(unsigned long *), + GFP_KERNEL); + if (!mapping->bitmaps) + goto err2; + + mapping->bitmaps[0] = kzalloc(bitmap_size, GFP_KERNEL); + if (!mapping->bitmaps[0]) + goto err3; + + mapping->nr_bitmaps = 1; + mapping->extensions = extensions; + mapping->base = base; + mapping->bits = BITS_PER_BYTE * bitmap_size; + + spin_lock_init(&mapping->lock); + + mapping->domain = iommu_domain_alloc(bus); + if (!mapping->domain) + goto err4; + + kref_init(&mapping->kref); + return mapping; +err4: + kfree(mapping->bitmaps[0]); +err3: + kfree(mapping->bitmaps); +err2: + kfree(mapping); +err: + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(arm_iommu_create_mapping); + +static void release_iommu_mapping(struct kref *kref) +{ + int i; + struct dma_iommu_mapping *mapping = + container_of(kref, struct dma_iommu_mapping, kref); + + iommu_domain_free(mapping->domain); + for (i = 0; i < mapping->nr_bitmaps; i++) + kfree(mapping->bitmaps[i]); + kfree(mapping->bitmaps); + kfree(mapping); +} + +static int extend_iommu_mapping(struct dma_iommu_mapping *mapping) +{ + int next_bitmap; + + if (mapping->nr_bitmaps >= mapping->extensions) + return -EINVAL; + + next_bitmap = mapping->nr_bitmaps; + mapping->bitmaps[next_bitmap] = kzalloc(mapping->bitmap_size, + GFP_ATOMIC); + if (!mapping->bitmaps[next_bitmap]) + return -ENOMEM; + + mapping->nr_bitmaps++; + + return 0; +} + +void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping) +{ + if (mapping) + kref_put(&mapping->kref, release_iommu_mapping); +} +EXPORT_SYMBOL_GPL(arm_iommu_release_mapping); + +static 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); + to_dma_iommu_mapping(dev) = mapping; + + pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev)); + return 0; +} + +/** + * 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 = __arm_iommu_attach_device(dev, mapping); + if (err) + return err; + + set_dma_ops(dev, &iommu_ops); + return 0; +} +EXPORT_SYMBOL_GPL(arm_iommu_attach_device); + +/** + * arm_iommu_detach_device + * @dev: valid struct device pointer + * + * Detaches the provided device from a previously attached map. + * This overwrites the dma_ops pointer with appropriate non-IOMMU ops. + */ +void arm_iommu_detach_device(struct device *dev) +{ + struct dma_iommu_mapping *mapping; + + mapping = to_dma_iommu_mapping(dev); + if (!mapping) { + dev_warn(dev, "Not attached\n"); + return; + } + + iommu_detach_device(mapping->domain, dev); + kref_put(&mapping->kref, release_iommu_mapping); + to_dma_iommu_mapping(dev) = NULL; + set_dma_ops(dev, NULL); + + pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); +} +EXPORT_SYMBOL_GPL(arm_iommu_detach_device); + +static void arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *iommu, bool coherent) +{ + struct dma_iommu_mapping *mapping; + + mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); + if (IS_ERR(mapping)) { + pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", + size, dev_name(dev)); + return; + } + + if (__arm_iommu_attach_device(dev, mapping)) { + pr_warn("Failed to attached device %s to IOMMU_mapping\n", + dev_name(dev)); + arm_iommu_release_mapping(mapping); + return; + } + + set_dma_ops(dev, &iommu_ops); +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + + if (!mapping) + return; + + arm_iommu_detach_device(dev); + arm_iommu_release_mapping(mapping); +} + +#else + +static void arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *iommu, bool coherent) +{ +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) { } + +#endif /* CONFIG_ARM_DMA_USE_IOMMU */ + +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *iommu, bool coherent) +{ + /* + * Due to legacy code that sets the ->dma_coherent flag from a bus + * notifier we can't just assign coherent to the ->dma_coherent flag + * here, but instead have to make sure we only set but never clear it + * for now. + */ + if (coherent) + dev->dma_coherent = true; + + /* + * Don't override the dma_ops if they have already been set. Ideally + * this should be the only location where dma_ops are set, remove this + * check when all other callers of set_dma_ops will have disappeared. + */ + if (dev->dma_ops) + return; + + if (iommu) + arm_setup_iommu_dma_ops(dev, dma_base, size, iommu, coherent); + + xen_setup_dma_ops(dev); + dev->archdata.dma_ops_setup = true; +} + +void arch_teardown_dma_ops(struct device *dev) +{ + if (!dev->archdata.dma_ops_setup) + return; + + arm_teardown_iommu_dma_ops(dev); + /* Let arch_setup_dma_ops() start again from scratch upon re-probe */ + set_dma_ops(dev, NULL); +} + +void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, + enum dma_data_direction dir) +{ + __dma_page_cpu_to_dev(phys_to_page(paddr), paddr & (PAGE_SIZE - 1), + size, dir); +} + +void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, + enum dma_data_direction dir) +{ + __dma_page_dev_to_cpu(phys_to_page(paddr), paddr & (PAGE_SIZE - 1), + size, dir); +} + +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) +{ + return __dma_alloc(dev, size, dma_handle, gfp, + __get_dma_pgprot(attrs, PAGE_KERNEL), false, + attrs, __builtin_return_address(0)); +} + +void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t dma_handle, unsigned long attrs) +{ + __arm_dma_free(dev, size, cpu_addr, dma_handle, attrs, false); +} |