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dma-mapping.c 51.38 KiB
/*
* 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/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 <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 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;
}
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
#ifdef CONFIG_HUGETLB_PAGE
#warning ARM Coherent DMA allocator does not (yet) support huge TLB
#endif
static void *__alloc_from_contiguous(struct device *dev, size_t size,
pgprot_t prot, struct page **ret_page,
const void *caller);
static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
pgprot_t prot, struct page **ret_page,
const void *caller);
static void *
__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller)
{
struct vm_struct *area;
unsigned long addr;
/*
* DMA allocation can be mapped to user space, so lets
* set VM_USERMAP flags too.
*/
area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
caller);
if (!area)
return NULL;
addr = (unsigned long)area->addr;
area->phys_addr = __pfn_to_phys(page_to_pfn(page));
if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
vunmap((void *)addr);
return NULL;
}
return (void *)addr;
}
static void __dma_free_remap(void *cpu_addr, size_t size)
{
unsigned int flags = VM_ARM_DMA_CONSISTENT | VM_USERMAP;
struct vm_struct *area = find_vm_area(cpu_addr);
if (!area || (area->flags & flags) != flags) {
WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
return;
}
unmap_kernel_range((unsigned long)cpu_addr, size);
vunmap(cpu_addr);
}
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
struct dma_pool {
size_t size;
spinlock_t lock;
unsigned long *bitmap;
unsigned long nr_pages;
void *vaddr;
struct page **pages;
};
static struct dma_pool 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.vaddr);
/*
* 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)
{
struct dma_pool *pool = &atomic_pool;
pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);
gfp_t gfp = GFP_KERNEL | GFP_DMA;
unsigned long nr_pages = pool->size >> PAGE_SHIFT;
unsigned long *bitmap;
struct page *page;
struct page **pages;
void *ptr; int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!bitmap)
goto no_bitmap;
pages = kzalloc(nr_pages * sizeof(struct page *), GFP_KERNEL);
if (!pages)
goto no_pages;
if (IS_ENABLED(CONFIG_DMA_CMA))
ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page,
atomic_pool_init);
else
ptr = __alloc_remap_buffer(NULL, pool->size, gfp, prot, &page,
atomic_pool_init);
if (ptr) {
int i;
for (i = 0; i < nr_pages; i++)
pages[i] = page + i;
spin_lock_init(&pool->lock);
pool->vaddr = ptr;
pool->pages = pages;
pool->bitmap = bitmap;
pool->nr_pages = nr_pages;
pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
(unsigned)pool->size / 1024);
return 0;
}
kfree(pages);
no_pages:
kfree(bitmap);
no_bitmap:
pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
(unsigned)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
*/
for (addr = __phys_to_virt(start); addr < __phys_to_virt(end);
addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
iotable_init(&map, 1);
}
}
static 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)
{
struct page *page;
void *ptr;
page = __dma_alloc_buffer(dev, size, gfp);
if (!page)
return NULL;
ptr = __dma_alloc_remap(page, size, gfp, prot, caller);
if (!ptr) {
__dma_free_buffer(page, size);
return NULL;
}
*ret_page = page;
return ptr;
}
static void *__alloc_from_pool(size_t size, struct page **ret_page)
{
struct dma_pool *pool = &atomic_pool;
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned int pageno;
unsigned long flags;
void *ptr = NULL;
unsigned long align_mask;
if (!pool->vaddr) { WARN(1, "coherent pool not initialised!\n");
return NULL;
}
/*
* Align the region allocation - allocations from pool are rather
* small, so align them to their order in pages, minimum is a page
* size. This helps reduce fragmentation of the DMA space.
*/
align_mask = (1 << get_order(size)) - 1;
spin_lock_irqsave(&pool->lock, flags);
pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages,
0, count, align_mask);
if (pageno < pool->nr_pages) {
bitmap_set(pool->bitmap, pageno, count);
ptr = pool->vaddr + PAGE_SIZE * pageno;
*ret_page = pool->pages[pageno];
} else {
pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n"
"Please increase it with coherent_pool= kernel parameter!\n",
(unsigned)pool->size / 1024);
}
spin_unlock_irqrestore(&pool->lock, flags);
return ptr;
}
static bool __in_atomic_pool(void *start, size_t size)
{
struct dma_pool *pool = &atomic_pool;
void *end = start + size;
void *pool_start = pool->vaddr;
void *pool_end = pool->vaddr + pool->size;
if (start < pool_start || start >= pool_end)
return false;
if (end <= pool_end)
return true;
WARN(1, "Wrong coherent size(%p-%p) from atomic pool(%p-%p)\n",
start, end - 1, pool_start, pool_end - 1);
return false;
}
static int __free_from_pool(void *start, size_t size)
{
struct dma_pool *pool = &atomic_pool;
unsigned long pageno, count;
unsigned long flags;
if (!__in_atomic_pool(start, size))
return 0;
pageno = (start - pool->vaddr) >> PAGE_SHIFT;
count = size >> PAGE_SHIFT;
spin_lock_irqsave(&pool->lock, flags);
bitmap_clear(pool->bitmap, pageno, count);
spin_unlock_irqrestore(&pool->lock, flags);
return 1;
}
static void *__alloc_from_contiguous(struct device *dev, size_t size,
pgprot_t prot, struct page **ret_page,
const void *caller)
{ unsigned long order = get_order(size);
size_t count = size >> PAGE_SHIFT;
struct page *page;
void *ptr;
page = dma_alloc_from_contiguous(dev, count, order);
if (!page)
return NULL;
__dma_clear_buffer(page, size);
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);
}
*ret_page = page;
return ptr;
}
static void __free_from_contiguous(struct device *dev, struct page *page,
void *cpu_addr, size_t size)
{
if (PageHighMem(page))
__dma_free_remap(cpu_addr, size);
else
__dma_remap(page, size, pgprot_kernel);
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
}
static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
{
prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
pgprot_writecombine(prot) :
pgprot_dmacoherent(prot);
return prot;
}
#define nommu() 0
#else /* !CONFIG_MMU */
#define nommu() 1
#define __get_dma_pgprot(attrs, prot) __pgprot(0)
#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL
#define __alloc_from_pool(size, ret_page) NULL
#define __alloc_from_contiguous(dev, size, prot, ret, c) NULL
#define __free_from_pool(cpu_addr, size) 0
#define __free_from_contiguous(dev, page, cpu_addr, size) 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, const void *caller)
{
u64 mask = get_coherent_dma_mask(dev);
struct page *page = NULL;
void *addr;
#ifdef CONFIG_DMA_API_DEBUG
u64 limit = (mask + 1) & ~mask;
if (limit && size >= limit) {
dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
size, mask);
return NULL;
}
#endif
if (!mask)
return NULL;
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
/*
* Following is a work-around (a.k.a. hack) to prevent pages
* with __GFP_COMP being passed to split_page() which cannot
* 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);
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 (!IS_ENABLED(CONFIG_DMA_CMA))
addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
else
addr = __alloc_from_contiguous(dev, size, prot, &page, caller);
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 *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t gfp, struct dma_attrs *attrs)
{
pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
void *memory;
if (dma_alloc_from_coherent(dev, size, handle, &memory))
return memory;
return __dma_alloc(dev, size, handle, gfp, prot, false,
__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, pgprot_kernel);
void *memory;
if (dma_alloc_from_coherent(dev, size, handle, &memory))
return memory;
return __dma_alloc(dev, size, handle, gfp, prot, true,
__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));
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 (!IS_ENABLED(CONFIG_DMA_CMA)) {
__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);
}}
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)
{
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? */
}
static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
unsigned long paddr = page_to_phys(page) + off;
/* 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 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)
{
if (mask < (u64)arm_dma_limit)
return 0;
return 1;
}
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 inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
size_t size)
{
unsigned int order = get_order(size);
unsigned int align = 0;
unsigned int count, start;
unsigned long flags;
if (order > CONFIG_ARM_DMA_IOMMU_ALIGNMENT)
order = CONFIG_ARM_DMA_IOMMU_ALIGNMENT;
count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) + (1 << mapping->order) - 1) >> mapping->order;
if (order > mapping->order)
align = (1 << (order - mapping->order)) - 1;
spin_lock_irqsave(&mapping->lock, flags);
start = bitmap_find_next_zero_area(mapping->bitmap, mapping->bits, 0,
count, align);
if (start > mapping->bits) {
spin_unlock_irqrestore(&mapping->lock, flags);
return DMA_ERROR_CODE;
}
bitmap_set(mapping->bitmap, start, count);
spin_unlock_irqrestore(&mapping->lock, flags);
return mapping->base + (start << (mapping->order + PAGE_SHIFT));
}
static inline void __free_iova(struct dma_iommu_mapping *mapping,
dma_addr_t addr, size_t size)
{
unsigned int start = (addr - mapping->base) >>
(mapping->order + PAGE_SHIFT);
unsigned int count = ((size >> PAGE_SHIFT) +
(1 << mapping->order) - 1) >> mapping->order;
unsigned long flags;
spin_lock_irqsave(&mapping->lock, flags);
bitmap_clear(mapping->bitmap, start, count);
spin_unlock_irqrestore(&mapping->lock, flags);
}
static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
gfp_t gfp, struct 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);
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 = __fls(count);
pages[i] = alloc_pages(gfp, order);
while (!pages[i] && order)
pages[i] = alloc_pages(gfp, --order);
if (!pages[i])
goto error;
if (order) {
split_page(pages[i], order);
j = 1 << order;
while (--j)
pages[i + j] = pages[i] + j;
}
__dma_clear_buffer(pages[i], PAGE_SIZE << order);
i += 1 << order;
count -= 1 << order;
}
return pages;
error:
while (i--)
if (pages[i])
__free_pages(pages[i], 0);
if (array_size <= PAGE_SIZE)
kfree(pages);
else
vfree(pages);
return NULL;
}
static int __iommu_free_buffer(struct device *dev, struct page **pages,
size_t size, 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)
{
unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct vm_struct *area;
unsigned long p;
area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
caller);
if (!area)
return NULL;
area->pages = pages;
area->nr_pages = nr_pages;
p = (unsigned long)area->addr;
for (i = 0; i < nr_pages; i++) {
phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
goto err;
p += PAGE_SIZE;
}
return area->addr;
err:
unmap_kernel_range((unsigned long)area->addr, size);
vunmap(area->addr);
return NULL;
}
/*
* Create a mapping in device IO address space for specified pages
*/
static dma_addr_t
__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
{
struct dma_iommu_mapping *mapping = dev->archdata.mapping;
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
dma_addr_t dma_addr, iova;
int i, ret = DMA_ERROR_CODE;
dma_addr = __alloc_iova(mapping, size);
if (dma_addr == DMA_ERROR_CODE)
return dma_addr;
iova = dma_addr;
for (i = 0; i < count; ) {
unsigned int next_pfn = page_to_pfn(pages[i]) + 1;
phys_addr_t phys = page_to_phys(pages[i]);
unsigned int len, j;
for (j = i + 1; j < count; j++, next_pfn++)
if (page_to_pfn(pages[j]) != next_pfn)
break;
len = (j - i) << PAGE_SHIFT;
ret = iommu_map(mapping->domain, iova, phys, len,
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 = dev->archdata.mapping;
/*
* add optional in-page offset from iova to size and align
* result to page size
*/
size = PAGE_ALIGN((iova & ~PAGE_MASK) + size);
iova &= PAGE_MASK;
iommu_unmap(mapping->domain, iova, size); __free_iova(mapping, iova, size);
return 0;
}
static struct page **__atomic_get_pages(void *addr)
{
struct dma_pool *pool = &atomic_pool;
struct page **pages = pool->pages;
int offs = (addr - pool->vaddr) >> PAGE_SHIFT;
return pages + offs;
}
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, pgprot_kernel);
struct page **pages;
void *addr = NULL;
*handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);
if (gfp & GFP_ATOMIC)
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)) {
unmap_kernel_range((unsigned long)cpu_addr, size);
vunmap(cpu_addr);
}
__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 = dev->archdata.mapping;
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 = dev->archdata.mapping;
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 = dev->archdata.mapping;
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 = dev->archdata.mapping;
dma_addr_t iova = handle & PAGE_MASK;
struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
int offset = handle & ~PAGE_MASK;
int len = PAGE_ALIGN(size + offset);
if (!iova)
return;
if (!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 = dev->archdata.mapping;
dma_addr_t iova = handle & PAGE_MASK;
struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
unsigned int offset = handle & ~PAGE_MASK;
if (!iova)
return;
__dma_page_dev_to_cpu(page, offset, size, dir);
}
static void arm_iommu_sync_single_for_device(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
struct dma_iommu_mapping *mapping = dev->archdata.mapping;
dma_addr_t iova = handle & PAGE_MASK;
struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
unsigned int offset = handle & ~PAGE_MASK;
if (!iova)
return;
__dma_page_cpu_to_dev(page, offset, size, dir);
}
struct dma_map_ops iommu_ops = {
.alloc = arm_iommu_alloc_attrs,
.free = arm_iommu_free_attrs,
.mmap = arm_iommu_mmap_attrs,
.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: size of the valid IO address space
* @order: accuracy of the IO addresses allocations
*
* Creates a mapping structure which holds information about used/unused
* IO address ranges, which is required to perform memory allocation and
* mapping with IOMMU aware functions.
*
* The client device need to be attached to the mapping with
* arm_iommu_attach_device function.
*/
struct dma_iommu_mapping *
arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
int order)
{
unsigned int count = size >> (PAGE_SHIFT + order);
unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
struct dma_iommu_mapping *mapping;
int err = -ENOMEM;
if (!count)
return ERR_PTR(-EINVAL);
mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
if (!mapping)
goto err;
mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!mapping->bitmap)
goto err2;
mapping->base = base;
mapping->bits = BITS_PER_BYTE * bitmap_size;
mapping->order = order;
spin_lock_init(&mapping->lock);
mapping->domain = iommu_domain_alloc(bus);
if (!mapping->domain)
goto err3;
kref_init(&mapping->kref);
return mapping;
err3:
kfree(mapping->bitmap);
err2:
kfree(mapping);
err: return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(arm_iommu_create_mapping);
static void release_iommu_mapping(struct kref *kref)
{
struct dma_iommu_mapping *mapping =
container_of(kref, struct dma_iommu_mapping, kref);
iommu_domain_free(mapping->domain);
kfree(mapping->bitmap);
kfree(mapping);
}
void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
{
if (mapping)
kref_put(&mapping->kref, release_iommu_mapping);
}
EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
/**
* arm_iommu_attach_device
* @dev: valid struct device pointer
* @mapping: io address space mapping structure (returned from
* arm_iommu_create_mapping)
*
* Attaches specified io address space mapping to the provided device,
* this replaces the dma operations (dma_map_ops pointer) with the
* IOMMU aware version. More than one client might be attached to
* the same io address space mapping.
*/
int arm_iommu_attach_device(struct device *dev,
struct dma_iommu_mapping *mapping)
{
int err;
err = iommu_attach_device(mapping->domain, dev);
if (err)
return err;
kref_get(&mapping->kref);
dev->archdata.mapping = mapping;
set_dma_ops(dev, &iommu_ops);
pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
return 0;
}
EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
/**
* arm_iommu_detach_device
* @dev: valid struct device pointer
*
* Detaches the provided device from a previously attached map.
* This voids the dma operations (dma_map_ops pointer)
*/
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);
dev->archdata.mapping = NULL; set_dma_ops(dev, NULL);
pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
}
EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
#endif