/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mm.h" static u64 get_coherent_dma_mask(struct device *dev) { u64 mask = (u64)arm_dma_limit; 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 ((~mask) & (u64)arm_dma_limit) { dev_warn(dev, "coherent DMA mask %#llx is smaller " "than system GFP_DMA mask %#llx\n", mask, (u64)arm_dma_limit); return 0; } } return mask; } /* * 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; void *ptr; u64 mask = get_coherent_dma_mask(dev); #ifdef CONFIG_DMA_API_DEBUG u64 limit = (mask + 1) & ~mask; if (limit && size >= limit) { dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n", size, mask); return NULL; } #endif if (!mask) return NULL; if (mask < 0xffffffffULL) gfp |= GFP_DMA; page = alloc_pages(gfp, order); if (!page) 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); /* * Ensure that the allocated pages are zeroed, and that any data * lurking in the kernel direct-mapped region is invalidated. */ ptr = page_address(page); memset(ptr, 0, size); dmac_flush_range(ptr, ptr + size); outer_flush_range(__pa(ptr), __pa(ptr) + size); 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 /* Sanity check size */ #if (CONSISTENT_DMA_SIZE % SZ_2M) #error "CONSISTENT_DMA_SIZE must be multiple of 2MiB" #endif #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) #define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PMD_SHIFT) #define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PMD_SHIFT) /* * These are the page tables (2MB each) covering uncached, DMA consistent allocations */ static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; #include "vmregion.h" static struct arm_vmregion_head consistent_head = { .vm_lock = __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock), .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), .vm_start = CONSISTENT_BASE, .vm_end = CONSISTENT_END, }; #ifdef CONFIG_HUGETLB_PAGE #error ARM Coherent DMA allocator does not (yet) support huge TLB #endif /* * Initialise the consistent memory allocation. */ static int __init consistent_init(void) { int ret = 0; pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; int i = 0; u32 base = CONSISTENT_BASE; do { pgd = pgd_offset(&init_mm, base); pud = pud_alloc(&init_mm, pgd, base); if (!pud) { printk(KERN_ERR "%s: no pud tables\n", __func__); ret = -ENOMEM; break; } pmd = pmd_alloc(&init_mm, pud, base); if (!pmd) { printk(KERN_ERR "%s: no pmd tables\n", __func__); ret = -ENOMEM; break; } WARN_ON(!pmd_none(*pmd)); pte = pte_alloc_kernel(pmd, base); if (!pte) { printk(KERN_ERR "%s: no pte tables\n", __func__); ret = -ENOMEM; break; } consistent_pte[i++] = pte; base += PMD_SIZE; } while (base < CONSISTENT_END); return ret; } core_initcall(consistent_init); static void * __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot) { struct arm_vmregion *c; size_t align; int bit; if (!consistent_pte[0]) { printk(KERN_ERR "%s: not initialised\n", __func__); dump_stack(); return NULL; } /* * Align the virtual region allocation - maximum alignment is * a section size, minimum is a page size. This helps reduce * fragmentation of the DMA space, and also prevents allocations * smaller than a section from crossing a section boundary. */ bit = fls(size - 1); if (bit > SECTION_SHIFT) bit = SECTION_SHIFT; align = 1 << bit; /* * Allocate a virtual address in the consistent mapping region. */ c = arm_vmregion_alloc(&consistent_head, align, size, gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); if (c) { pte_t *pte; int idx = CONSISTENT_PTE_INDEX(c->vm_start); u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); pte = consistent_pte[idx] + off; c->vm_pages = page; do { BUG_ON(!pte_none(*pte)); set_pte_ext(pte, mk_pte(page, prot), 0); page++; pte++; off++; if (off >= PTRS_PER_PTE) { off = 0; pte = consistent_pte[++idx]; } } while (size -= PAGE_SIZE); dsb(); return (void *)c->vm_start; } return NULL; } static void __dma_free_remap(void *cpu_addr, size_t size) { struct arm_vmregion *c; unsigned long addr; pte_t *ptep; int idx; u32 off; c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr); if (!c) { printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", __func__, cpu_addr); dump_stack(); return; } if ((c->vm_end - c->vm_start) != size) { printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", __func__, c->vm_end - c->vm_start, size); dump_stack(); size = c->vm_end - c->vm_start; } idx = CONSISTENT_PTE_INDEX(c->vm_start); off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); ptep = consistent_pte[idx] + off; addr = c->vm_start; do { pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); ptep++; addr += PAGE_SIZE; off++; if (off >= PTRS_PER_PTE) { off = 0; ptep = consistent_pte[++idx]; } if (pte_none(pte) || !pte_present(pte)) printk(KERN_CRIT "%s: bad page in kernel page table\n", __func__); } while (size -= PAGE_SIZE); flush_tlb_kernel_range(c->vm_start, c->vm_end); arm_vmregion_free(&consistent_head, c); } #else /* !CONFIG_MMU */ #define __dma_alloc_remap(page, size, gfp, prot) page_address(page) #define __dma_free_remap(addr, size) do { } while (0) #endif /* CONFIG_MMU */ static void * __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, pgprot_t prot) { struct page *page; void *addr; *handle = ~0; size = PAGE_ALIGN(size); page = __dma_alloc_buffer(dev, size, gfp); if (!page) return NULL; if (!arch_is_coherent()) addr = __dma_alloc_remap(page, size, gfp, prot); else addr = page_address(page); if (addr) *handle = pfn_to_dma(dev, page_to_pfn(page)); return addr; } /* * Allocate DMA-coherent memory space and return both the kernel remapped * virtual and bus address for that space. */ void * dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) { void *memory; if (dma_alloc_from_coherent(dev, size, handle, &memory)) return memory; return __dma_alloc(dev, size, handle, gfp, pgprot_dmacoherent(pgprot_kernel)); } EXPORT_SYMBOL(dma_alloc_coherent); /* * Allocate a writecombining region, in much the same way as * dma_alloc_coherent above. */ void * dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) { return __dma_alloc(dev, size, handle, gfp, pgprot_writecombine(pgprot_kernel)); } EXPORT_SYMBOL(dma_alloc_writecombine); static int dma_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size) { int ret = -ENXIO; #ifdef CONFIG_MMU unsigned long user_size, kern_size; struct arm_vmregion *c; user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); if (c) { unsigned long off = vma->vm_pgoff; kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; if (off < kern_size && user_size <= (kern_size - off)) { ret = remap_pfn_range(vma, vma->vm_start, page_to_pfn(c->vm_pages) + off, user_size << PAGE_SHIFT, vma->vm_page_prot); } } #endif /* CONFIG_MMU */ return ret; } int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size) { vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot); return dma_mmap(dev, vma, cpu_addr, dma_addr, size); } EXPORT_SYMBOL(dma_mmap_coherent); int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size) { vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); return dma_mmap(dev, vma, cpu_addr, dma_addr, size); } EXPORT_SYMBOL(dma_mmap_writecombine); /* * free a page as defined by the above mapping. * Must not be called with IRQs disabled. */ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle) { WARN_ON(irqs_disabled()); if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) return; size = PAGE_ALIGN(size); if (!arch_is_coherent()) __dma_free_remap(cpu_addr, size); __dma_free_buffer(pfn_to_page(dma_to_pfn(dev, handle)), size); } EXPORT_SYMBOL(dma_free_coherent); /* * Make an area consistent for devices. * Note: Drivers should NOT use this function directly, as it will break * platforms with CONFIG_DMABOUNCE. * Use the driver DMA support - see dma-mapping.h (dma_sync_*) */ void ___dma_single_cpu_to_dev(const void *kaddr, size_t size, enum dma_data_direction dir) { unsigned long paddr; BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1)); dmac_map_area(kaddr, size, dir); paddr = __pa(kaddr); if (dir == DMA_FROM_DEVICE) { outer_inv_range(paddr, paddr + size); } else { outer_clean_range(paddr, paddr + size); } /* FIXME: non-speculating: flush on bidirectional mappings? */ } EXPORT_SYMBOL(___dma_single_cpu_to_dev); void ___dma_single_dev_to_cpu(const void *kaddr, size_t size, enum dma_data_direction dir) { BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1)); /* FIXME: non-speculating: not required */ /* don't bother invalidating if DMA to device */ if (dir != DMA_TO_DEVICE) { unsigned long paddr = __pa(kaddr); outer_inv_range(paddr, paddr + size); } dmac_unmap_area(kaddr, size, dir); } EXPORT_SYMBOL(___dma_single_dev_to_cpu); static void dma_cache_maint_page(struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir, void (*op)(const void *, size_t, int)) { /* * 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. */ size_t left = size; do { size_t len = left; void *vaddr; if (PageHighMem(page)) { if (len + offset > PAGE_SIZE) { if (offset >= PAGE_SIZE) { page += offset / PAGE_SIZE; offset %= PAGE_SIZE; } len = PAGE_SIZE - offset; } vaddr = kmap_high_get(page); if (vaddr) { vaddr += offset; op(vaddr, len, dir); kunmap_high(page); } else if (cache_is_vipt()) { /* unmapped pages might still be cached */ vaddr = kmap_atomic(page); op(vaddr + offset, len, dir); kunmap_atomic(vaddr); } } else { vaddr = page_address(page) + offset; op(vaddr, len, dir); } offset = 0; page++; left -= len; } while (left); } void ___dma_page_cpu_to_dev(struct page *page, unsigned long off, size_t size, enum dma_data_direction dir) { unsigned long 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? */ } EXPORT_SYMBOL(___dma_page_cpu_to_dev); void ___dma_page_dev_to_cpu(struct page *page, unsigned long off, size_t size, enum dma_data_direction dir) { unsigned long paddr = page_to_phys(page) + off; /* FIXME: non-speculating: not required */ /* 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 this page to avoid extra flushing. */ if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE) set_bit(PG_dcache_clean, &page->flags); } EXPORT_SYMBOL(___dma_page_dev_to_cpu); /** * dma_map_sg - map a set of SG buffers for streaming mode DMA * @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 dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir) { struct scatterlist *s; int i, j; BUG_ON(!valid_dma_direction(dir)); for_each_sg(sg, s, nents, i) { s->dma_address = __dma_map_page(dev, sg_page(s), s->offset, s->length, dir); if (dma_mapping_error(dev, s->dma_address)) goto bad_mapping; } debug_dma_map_sg(dev, sg, nents, nents, dir); return nents; bad_mapping: for_each_sg(sg, s, i, j) __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir); return 0; } EXPORT_SYMBOL(dma_map_sg); /** * 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 dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir) { struct scatterlist *s; int i; debug_dma_unmap_sg(dev, sg, nents, dir); for_each_sg(sg, s, nents, i) __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir); } EXPORT_SYMBOL(dma_unmap_sg); /** * dma_sync_sg_for_cpu * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices * @sg: list of buffers * @nents: number of buffers to map (returned from dma_map_sg) * @dir: DMA transfer direction (same as was passed to dma_map_sg) */ void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir) { struct scatterlist *s; int i; for_each_sg(sg, s, nents, i) { if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0, sg_dma_len(s), dir)) continue; __dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir); } debug_dma_sync_sg_for_cpu(dev, sg, nents, dir); } EXPORT_SYMBOL(dma_sync_sg_for_cpu); /** * dma_sync_sg_for_device * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices * @sg: list of buffers * @nents: number of buffers to map (returned from dma_map_sg) * @dir: DMA transfer direction (same as was passed to dma_map_sg) */ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir) { struct scatterlist *s; int i; for_each_sg(sg, s, nents, i) { if (!dmabounce_sync_for_device(dev, sg_dma_address(s), 0, sg_dma_len(s), dir)) continue; __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); } debug_dma_sync_sg_for_device(dev, sg, nents, dir); } EXPORT_SYMBOL(dma_sync_sg_for_device); /* * 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) { if (mask < (u64)arm_dma_limit) return 0; return 1; } EXPORT_SYMBOL(dma_supported); int dma_set_mask(struct device *dev, u64 dma_mask) { if (!dev->dma_mask || !dma_supported(dev, dma_mask)) return -EIO; #ifndef CONFIG_DMABOUNCE *dev->dma_mask = dma_mask; #endif return 0; } EXPORT_SYMBOL(dma_set_mask); #define PREALLOC_DMA_DEBUG_ENTRIES 4096 static int __init dma_debug_do_init(void) { dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); return 0; } fs_initcall(dma_debug_do_init);