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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/arm/mm/dma-mapping.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r-- | arch/arm/mm/dma-mapping.c | 735 |
1 files changed, 735 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c new file mode 100644 index 00000000..cb5821be --- /dev/null +++ b/arch/arm/mm/dma-mapping.c @@ -0,0 +1,735 @@ +/* + * 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/module.h> +#include <linux/mm.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/highmem.h> +#include <linux/slab.h> + +#include <asm/memory.h> +#include <asm/highmem.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/sizes.h> +#include <asm/mach/arch.h> + +#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 + +#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - consistent_base) >> PAGE_SHIFT) +#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PMD_SHIFT) + +/* + * These are the page tables (2MB each) covering uncached, DMA consistent allocations + */ +static pte_t **consistent_pte; + +#define DEFAULT_CONSISTENT_DMA_SIZE SZ_4M + +unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE; + +void __init init_consistent_dma_size(unsigned long size) +{ + unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M); + + BUG_ON(consistent_pte); /* Check we're called before DMA region init */ + BUG_ON(base < VMALLOC_END); + + /* Grow region to accommodate specified size */ + if (base < consistent_base) + consistent_base = base; +} + +#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_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; + unsigned long base = consistent_base; + unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT; + + consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL); + if (!consistent_pte) { + pr_err("%s: no memory\n", __func__); + return -ENOMEM; + } + + pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END); + consistent_head.vm_start = 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, + const void *caller) +{ + struct arm_vmregion *c; + size_t align; + int bit; + + if (!consistent_pte) { + 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), caller); + 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, c) 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, const void *caller) +{ + struct page *page; + void *addr; + + /* + * 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 = ~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, caller); + else + addr = page_address(page); + + if (addr) + *handle = pfn_to_dma(dev, page_to_pfn(page)); + else + __dma_free_buffer(page, size); + + 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), + __builtin_return_address(0)); +} +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), + __builtin_return_address(0)); +} +EXPORT_SYMBOL(dma_alloc_writecombine); + +static int dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size) +{ + int 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) +{ +#ifdef CONFIG_MMU + arm_vmregion_create_proc("dma-mappings", &consistent_head); +#endif + dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); + return 0; +} +fs_initcall(dma_debug_do_init); |