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Diffstat (limited to 'kernel/arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | kernel/arch/arm/mm/dma-mapping.c | 2128 |
1 files changed, 2128 insertions, 0 deletions
diff --git a/kernel/arch/arm/mm/dma-mapping.c b/kernel/arch/arm/mm/dma-mapping.c new file mode 100644 index 000000000..7e7583ddd --- /dev/null +++ b/kernel/arch/arm/mm/dma-mapping.c @@ -0,0 +1,2128 @@ +/* + * linux/arch/arm/mm/dma-mapping.c + * + * Copyright (C) 2000-2004 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * DMA uncached mapping support. + */ +#include <linux/bootmem.h> +#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-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/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/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 (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + __dma_page_cpu_to_dev(page, offset, size, dir); + return pfn_to_dma(dev, page_to_pfn(page)) + offset; +} + +static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + 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 (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + __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)); + __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)); + __dma_page_cpu_to_dev(page, offset, size, dir); +} + +struct dma_map_ops arm_dma_ops = { + .alloc = arm_dma_alloc, + .free = arm_dma_free, + .mmap = arm_dma_mmap, + .get_sgtable = arm_dma_get_sgtable, + .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 void *arm_coherent_dma_alloc(struct device *dev, size_t size, + dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs); +static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs); + +struct dma_map_ops arm_coherent_dma_ops = { + .alloc = arm_coherent_dma_alloc, + .free = arm_coherent_dma_free, + .mmap = arm_dma_mmap, + .get_sgtable = arm_dma_get_sgtable, + .map_page = arm_coherent_dma_map_page, + .map_sg = arm_dma_map_sg, + .set_dma_mask = arm_dma_set_mask, +}; +EXPORT_SYMBOL(arm_coherent_dma_ops); + +static int __dma_supported(struct device *dev, u64 mask, bool warn) +{ + unsigned long max_dma_pfn; + + /* + * If the mask allows for more memory than we can address, + * and we actually have that much memory, then we must + * indicate that DMA to this device is not supported. + */ + if (sizeof(mask) != sizeof(dma_addr_t) && + mask > (dma_addr_t)~0 && + dma_to_pfn(dev, ~0) < max_pfn - 1) { + if (warn) { + dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n", + mask); + dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n"); + } + return 0; + } + + max_dma_pfn = min(max_pfn, arm_dma_pfn_limit); + + /* + * Translate the device's DMA mask to a PFN limit. This + * PFN number includes the page which we can DMA to. + */ + if (dma_to_pfn(dev, mask) < max_dma_pfn) { + if (warn) + dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n", + mask, + dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1, + max_dma_pfn + 1); + return 0; + } + + return 1; +} + +static u64 get_coherent_dma_mask(struct device *dev) +{ + u64 mask = (u64)DMA_BIT_MASK(32); + + if (dev) { + mask = dev->coherent_dma_mask; + + /* + * Sanity check the DMA mask - it must be non-zero, and + * must be able to be satisfied by a DMA allocation. + */ + if (mask == 0) { + dev_warn(dev, "coherent DMA mask is unset\n"); + return 0; + } + + if (!__dma_supported(dev, mask, true)) + return 0; + } + + return mask; +} + +static void __dma_clear_buffer(struct page *page, size_t size) +{ + /* + * 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); + dmac_flush_range(ptr, ptr + PAGE_SIZE); + kunmap_atomic(ptr); + page++; + size -= PAGE_SIZE; + } + outer_flush_range(base, end); + } else { + void *ptr = page_address(page); + 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. + */ +static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp) +{ + 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); + + 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++; + } +} + +#ifdef CONFIG_MMU + +static void *__alloc_from_contiguous(struct device *dev, size_t size, + pgprot_t prot, struct page **ret_page, + const void *caller, bool want_vaddr); + +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); + +static void * +__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, + const void *caller) +{ + /* + * DMA allocation can be mapped to user space, so lets + * set VM_USERMAP flags too. + */ + return dma_common_contiguous_remap(page, size, + VM_ARM_DMA_CONSISTENT | VM_USERMAP, + prot, caller); +} + +static void __dma_free_remap(void *cpu_addr, size_t size) +{ + dma_common_free_remap(cpu_addr, size, + VM_ARM_DMA_CONSISTENT | VM_USERMAP); +} + +#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K +static struct gen_pool *atomic_pool; + +static size_t atomic_pool_size = 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); + +void __init init_dma_coherent_pool_size(unsigned long size) +{ + /* + * Catch any attempt to set the pool size too late. + */ + BUG_ON(atomic_pool); + + /* + * Set architecture specific coherent pool size only if + * it has not been changed by kernel command line parameter. + */ + if (atomic_pool_size == DEFAULT_DMA_COHERENT_POOL_SIZE) + atomic_pool_size = size; +} + +/* + * 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; + + if (dev_get_cma_area(NULL)) + ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot, + &page, atomic_pool_init, true); + 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, + (void *)PAGE_SHIFT); + pr_info("DMA: preallocated %zd 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 %zx 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); + +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); + } +} + +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); + 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; + page = __dma_alloc_buffer(dev, size, gfp); + if (!page) + return NULL; + if (!want_vaddr) + goto out; + + ptr = __dma_alloc_remap(page, size, gfp, 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 addr_in_gen_pool(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) +{ + 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); + if (!page) + return NULL; + + __dma_clear_buffer(page, size); + + if (!want_vaddr) + goto out; + + if (PageHighMem(page)) { + ptr = __dma_alloc_remap(page, size, GFP_KERNEL, 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_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(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 nommu() 1 + +#define __get_dma_pgprot(attrs, prot) __pgprot(0) +#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c, wv) NULL +#define __alloc_from_pool(size, ret_page) NULL +#define __alloc_from_contiguous(dev, size, prot, ret, c, wv) NULL +#define __free_from_pool(cpu_addr, size) 0 +#define __free_from_contiguous(dev, page, cpu_addr, size, wv) do { } while (0) +#define __dma_free_remap(cpu_addr, size) do { } while (0) + +#endif /* CONFIG_MMU */ + +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, bool is_coherent, + struct dma_attrs *attrs, const void *caller) +{ + u64 mask = get_coherent_dma_mask(dev); + struct page *page = NULL; + void *addr; + bool want_vaddr; + +#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 + * 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); + + *handle = DMA_ERROR_CODE; + size = PAGE_ALIGN(size); + want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs); + + if (is_coherent || nommu()) + addr = __alloc_simple_buffer(dev, size, gfp, &page); + else if (!(gfp & __GFP_WAIT)) + addr = __alloc_from_pool(size, &page); + else if (!dev_get_cma_area(dev)) + addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr); + else + addr = __alloc_from_contiguous(dev, size, prot, &page, caller, want_vaddr); + + if (page) + *handle = pfn_to_dma(dev, page_to_pfn(page)); + + return want_vaddr ? addr : page; +} + +/* + * Allocate DMA-coherent memory space and return both the kernel remapped + * virtual and bus address for that space. + */ +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, PAGE_KERNEL); + void *memory; + + if (dma_alloc_from_coherent(dev, size, handle, &memory)) + return memory; + + return __dma_alloc(dev, size, handle, gfp, prot, false, + attrs, __builtin_return_address(0)); +} + +static void *arm_coherent_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, PAGE_KERNEL); + void *memory; + + if (dma_alloc_from_coherent(dev, size, handle, &memory)) + return memory; + + return __dma_alloc(dev, size, handle, gfp, prot, true, + attrs, __builtin_return_address(0)); +} + +/* + * Create userspace mapping for the DMA-coherent memory. + */ +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 nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long pfn = dma_to_pfn(dev, dma_addr); + unsigned long off = vma->vm_pgoff; + + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); + + if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) + return ret; + + if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + pfn + off, + vma->vm_end - vma->vm_start, + vma->vm_page_prot); + } +#endif /* CONFIG_MMU */ + + return ret; +} + +/* + * 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, struct dma_attrs *attrs, + bool is_coherent) +{ + struct page *page = pfn_to_page(dma_to_pfn(dev, handle)); + bool want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs); + + if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) + return; + + size = PAGE_ALIGN(size); + + if (is_coherent || nommu()) { + __dma_free_buffer(page, size); + } else if (__free_from_pool(cpu_addr, size)) { + return; + } else if (!dev_get_cma_area(dev)) { + if (want_vaddr) + __dma_free_remap(cpu_addr, size); + __dma_free_buffer(page, size); + } else { + /* + * Non-atomic allocations cannot be freed with IRQs disabled + */ + WARN_ON(irqs_disabled()); + __free_from_contiguous(dev, page, cpu_addr, size, want_vaddr); + } +} + +void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs) +{ + __arm_dma_free(dev, size, cpu_addr, handle, attrs, false); +} + +static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs) +{ + __arm_dma_free(dev, size, cpu_addr, handle, attrs, true); +} + +int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt, + void *cpu_addr, dma_addr_t handle, size_t size, + struct dma_attrs *attrs) +{ + struct page *page = pfn_to_page(dma_to_pfn(dev, handle)); + int ret; + + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); + if (unlikely(ret)) + return ret; + + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); + return 0; +} + +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, 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) +{ + 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; + } + } +} + +/** + * 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 + * @dir: DMA transfer direction + * + * Map a set of buffers described by scatterlist in streaming mode for DMA. + * This is the scatter-gather version of the dma_map_single interface. + * Here the scatter gather list elements are each tagged with the + * appropriate dma address and length. They are obtained via + * sg_dma_{address,length}. + * + * Device ownership issues as mentioned for dma_map_single are the same + * here. + */ +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; + + for_each_sg(sg, s, nents, i) { +#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; + } + return nents; + + bad_mapping: + for_each_sg(sg, s, i, j) + ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs); + return 0; +} + +/** + * 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) + * @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_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; + + for_each_sg(sg, s, nents, i) + ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs); +} + +/** + * 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 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) + ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length, + dir); +} + +/** + * 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 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) + ops->sync_single_for_device(dev, sg_dma_address(s), s->length, + dir); +} + +/* + * Return whether the given device DMA address mask can be supported + * properly. For example, if your device can only drive the low 24-bits + * during bus mastering, then you would pass 0x00ffffff as the mask + * to this function. + */ +int dma_supported(struct device *dev, u64 mask) +{ + return __dma_supported(dev, mask, false); +} +EXPORT_SYMBOL(dma_supported); + +int arm_dma_set_mask(struct device *dev, u64 dma_mask) +{ + if (!dev->dma_mask || !dma_supported(dev, dma_mask)) + return -EIO; + + *dev->dma_mask = dma_mask; + + return 0; +} + +#define PREALLOC_DMA_DEBUG_ENTRIES 4096 + +static int __init dma_debug_do_init(void) +{ + dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); + return 0; +} +fs_initcall(dma_debug_do_init); + +#ifdef CONFIG_ARM_DMA_USE_IOMMU + +/* 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_ERROR_CODE; + } + + 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_ERROR_CODE; + } + + 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); +} + +static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, + gfp_t gfp, struct dma_attrs *attrs) +{ + 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_KERNEL); + else + pages = vzalloc(array_size); + if (!pages) + return NULL; + + if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) + { + unsigned long order = get_order(size); + struct page *page; + + page = dma_alloc_from_contiguous(dev, count, order); + if (!page) + goto error; + + __dma_clear_buffer(page, size); + + for (i = 0; i < count; i++) + pages[i] = page + i; + + return pages; + } + + /* + * IOMMU can map any pages, so himem can also be used here + */ + gfp |= __GFP_NOWARN | __GFP_HIGHMEM; + + while (count) { + int j, order; + + for (order = __fls(count); order > 0; --order) { + /* + * We do not want OOM killer to be invoked as long + * as we can fall back to single pages, so we force + * __GFP_NORETRY for orders higher than zero. + */ + pages[i] = alloc_pages(gfp | __GFP_NORETRY, order); + if (pages[i]) + break; + } + + if (!pages[i]) { + /* + * Fall back to single page allocation. + * Might invoke OOM killer as last resort. + */ + 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); + 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, struct dma_attrs *attrs) +{ + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int i; + + if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) { + dma_release_from_contiguous(dev, pages[0], count); + } else { + 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, + const void *caller) +{ + return dma_common_pages_remap(pages, size, + VM_ARM_DMA_CONSISTENT | VM_USERMAP, prot, caller); +} + +/* + * 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 = to_dma_iommu_mapping(dev); + 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, + IOMMU_READ|IOMMU_WRITE); + 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 = 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, struct dma_attrs *attrs) +{ + struct vm_struct *area; + + if (__in_atomic_pool(cpu_addr, PAGE_SIZE)) + return __atomic_get_pages(cpu_addr); + + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return cpu_addr; + + area = find_vm_area(cpu_addr); + if (area && (area->flags & VM_ARM_DMA_CONSISTENT)) + return area->pages; + return NULL; +} + +static void *__iommu_alloc_atomic(struct device *dev, size_t size, + dma_addr_t *handle) +{ + struct page *page; + void *addr; + + addr = __alloc_from_pool(size, &page); + if (!addr) + return NULL; + + *handle = __iommu_create_mapping(dev, &page, size); + if (*handle == DMA_ERROR_CODE) + 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) +{ + __iommu_remove_mapping(dev, handle, size); + __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, struct dma_attrs *attrs) +{ + pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL); + struct page **pages; + void *addr = NULL; + + *handle = DMA_ERROR_CODE; + size = PAGE_ALIGN(size); + + if (!(gfp & __GFP_WAIT)) + return __iommu_alloc_atomic(dev, size, handle); + + /* + * 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); + if (!pages) + return NULL; + + *handle = __iommu_create_mapping(dev, pages, size); + if (*handle == DMA_ERROR_CODE) + goto err_buffer; + + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return pages; + + addr = __iommu_alloc_remap(pages, size, gfp, 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, + struct dma_attrs *attrs) +{ + unsigned long uaddr = vma->vm_start; + unsigned long usize = vma->vm_end - vma->vm_start; + struct page **pages = __iommu_get_pages(cpu_addr, attrs); + + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); + + if (!pages) + return -ENXIO; + + do { + int ret = vm_insert_page(vma, uaddr, *pages++); + if (ret) { + pr_err("Remapping memory failed: %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 page **pages; + size = PAGE_ALIGN(size); + + if (__in_atomic_pool(cpu_addr, size)) { + __iommu_free_atomic(dev, cpu_addr, handle, size); + return; + } + + pages = __iommu_get_pages(cpu_addr, attrs); + if (!pages) { + WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); + return; + } + + if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) { + dma_common_free_remap(cpu_addr, size, + VM_ARM_DMA_CONSISTENT | VM_USERMAP); + } + + __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, struct dma_attrs *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); +} + +static int __dma_direction_to_prot(enum dma_data_direction dir) +{ + int prot; + + switch (dir) { + case DMA_BIDIRECTIONAL: + prot = IOMMU_READ | IOMMU_WRITE; + break; + case DMA_TO_DEVICE: + prot = IOMMU_READ; + break; + case DMA_FROM_DEVICE: + prot = IOMMU_WRITE; + break; + default: + prot = 0; + } + + return prot; +} + +/* + * 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_attrs *attrs, + bool is_coherent) +{ + 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_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 (!is_coherent && + !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); + + prot = __dma_direction_to_prot(dir); + + 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; +} + +static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir, struct dma_attrs *attrs, + bool is_coherent) +{ + 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, attrs, is_coherent) < 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, attrs, + is_coherent) < 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_coherent_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 i/o coherent 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_coherent_iommu_map_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, struct dma_attrs *attrs) +{ + return __iommu_map_sg(dev, sg, nents, dir, attrs, true); +} + +/** + * 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) +{ + return __iommu_map_sg(dev, sg, nents, dir, attrs, false); +} + +static void __iommu_unmap_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, struct dma_attrs *attrs, + bool is_coherent) +{ + 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 (!is_coherent && + !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + __dma_page_dev_to_cpu(sg_page(s), s->offset, + s->length, dir); + } +} + +/** + * arm_coherent_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_coherent_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, struct dma_attrs *attrs) +{ + __iommu_unmap_sg(dev, sg, nents, dir, attrs, true); +} + +/** + * 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) +{ + __iommu_unmap_sg(dev, sg, nents, dir, attrs, false); +} + +/** + * 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) + __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) + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); +} + + +/** + * arm_coherent_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 + * + * Coherent IOMMU aware version of arm_dma_map_page() + */ +static dma_addr_t arm_coherent_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 = to_dma_iommu_mapping(dev); + dma_addr_t dma_addr; + int ret, prot, len = PAGE_ALIGN(size + offset); + + dma_addr = __alloc_iova(mapping, len); + if (dma_addr == DMA_ERROR_CODE) + return dma_addr; + + prot = __dma_direction_to_prot(dir); + + 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_ERROR_CODE; +} + +/** + * 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) +{ + if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + __dma_page_cpu_to_dev(page, offset, size, dir); + + return arm_coherent_iommu_map_page(dev, page, offset, size, dir, attrs); +} + +/** + * arm_coherent_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) + * + * Coherent IOMMU aware version of arm_dma_unmap_page() + */ +static void arm_coherent_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 = to_dma_iommu_mapping(dev); + dma_addr_t iova = handle & PAGE_MASK; + int offset = handle & ~PAGE_MASK; + int len = PAGE_ALIGN(size + offset); + + if (!iova) + return; + + iommu_unmap(mapping->domain, iova, len); + __free_iova(mapping, iova, len); +} + +/** + * 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 = to_dma_iommu_mapping(dev); + 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 (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + __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 = to_dma_iommu_mapping(dev); + 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_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 = 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, + .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, + + .set_dma_mask = arm_dma_set_mask, +}; + +struct dma_map_ops iommu_coherent_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_coherent_iommu_map_page, + .unmap_page = arm_coherent_iommu_unmap_page, + + .map_sg = arm_coherent_iommu_map_sg, + .unmap_sg = arm_coherent_iommu_unmap_sg, + + .set_dma_mask = arm_dma_set_mask, +}; + +/** + * 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 = kzalloc(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); + +static 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; + + pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); +} + +/** + * arm_iommu_detach_device + * @dev: valid struct device pointer + * + * Detaches the provided device from a previously attached map. + * This voids the dma operations (dma_map_ops pointer) + */ +void arm_iommu_detach_device(struct device *dev) +{ + __arm_iommu_detach_device(dev); + set_dma_ops(dev, NULL); +} +EXPORT_SYMBOL_GPL(arm_iommu_detach_device); + +static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent) +{ + return coherent ? &iommu_coherent_ops : &iommu_ops; +} + +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu) +{ + struct dma_iommu_mapping *mapping; + + if (!iommu) + return false; + + 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 false; + } + + 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 false; + } + + return true; +} + +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 bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu) +{ + return false; +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) { } + +#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops + +#endif /* CONFIG_ARM_DMA_USE_IOMMU */ + +static struct dma_map_ops *arm_get_dma_map_ops(bool coherent) +{ + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; +} + +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu, bool coherent) +{ + struct dma_map_ops *dma_ops; + + dev->archdata.dma_coherent = coherent; + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) + dma_ops = arm_get_iommu_dma_map_ops(coherent); + else + dma_ops = arm_get_dma_map_ops(coherent); + + set_dma_ops(dev, dma_ops); +} + +void arch_teardown_dma_ops(struct device *dev) +{ + arm_teardown_iommu_dma_ops(dev); +} |