- 根目录:
- drivers
- base
- dma-mapping.c
/*
* drivers/base/dma-mapping.c - arch-independent dma-mapping routines
*
* Copyright (c) 2006 SUSE Linux Products GmbH
* Copyright (c) 2006 Tejun Heo <teheo@suse.de>
*
* This file is released under the GPLv2.
*/
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <asm-generic/dma-coherent.h>
/*
* Managed DMA API
*/
struct dma_devres {
size_t size;
void *vaddr;
dma_addr_t dma_handle;
};
static void dmam_coherent_release(struct device *dev, void *res)
{
struct dma_devres *this = res;
dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
}
static void dmam_noncoherent_release(struct device *dev, void *res)
{
struct dma_devres *this = res;
dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
}
static int dmam_match(struct device *dev, void *res, void *match_data)
{
struct dma_devres *this = res, *match = match_data;
if (this->vaddr == match->vaddr) {
WARN_ON(this->size != match->size ||
this->dma_handle != match->dma_handle);
return 1;
}
return 0;
}
/**
* dmam_alloc_coherent - Managed dma_alloc_coherent()
* @dev: Device to allocate coherent memory for
* @size: Size of allocation
* @dma_handle: Out argument for allocated DMA handle
* @gfp: Allocation flags
*
* Managed dma_alloc_coherent(). Memory allocated using this function
* will be automatically released on driver detach.
*
* RETURNS:
* Pointer to allocated memory on success, NULL on failure.
*/
void * dmam_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
struct dma_devres *dr;
void *vaddr;
dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
if (!dr)
return NULL;
vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
if (!vaddr) {
devres_free(dr);
return NULL;
}
dr->vaddr = vaddr;
dr->dma_handle = *dma_handle;
dr->size = size;
devres_add(dev, dr);
return vaddr;
}
EXPORT_SYMBOL(dmam_alloc_coherent);
/**
* dmam_free_coherent - Managed dma_free_coherent()
* @dev: Device to free coherent memory for
* @size: Size of allocation
* @vaddr: Virtual address of the memory to free
* @dma_handle: DMA handle of the memory to free
*
* Managed dma_free_coherent().
*/
void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
struct dma_devres match_data = { size, vaddr, dma_handle };
dma_free_coherent(dev, size, vaddr, dma_handle);
WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
&match_data));
}
EXPORT_SYMBOL(dmam_free_coherent);
/**
* dmam_alloc_non_coherent - Managed dma_alloc_non_coherent()
* @dev: Device to allocate non_coherent memory for
* @size: Size of allocation
* @dma_handle: Out argument for allocated DMA handle
* @gfp: Allocation flags
*
* Managed dma_alloc_non_coherent(). Memory allocated using this
* function will be automatically released on driver detach.
*
* RETURNS:
* Pointer to allocated memory on success, NULL on failure.
*/
void *dmam_alloc_noncoherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
struct dma_devres *dr;
void *vaddr;
dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
if (!dr)
return NULL;
vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
if (!vaddr) {
devres_free(dr);
return NULL;
}
dr->vaddr = vaddr;
dr->dma_handle = *dma_handle;
dr->size = size;
devres_add(dev, dr);
return vaddr;
}
EXPORT_SYMBOL(dmam_alloc_noncoherent);
/**
* dmam_free_coherent - Managed dma_free_noncoherent()
* @dev: Device to free noncoherent memory for
* @size: Size of allocation
* @vaddr: Virtual address of the memory to free
* @dma_handle: DMA handle of the memory to free
*
* Managed dma_free_noncoherent().
*/
void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
struct dma_devres match_data = { size, vaddr, dma_handle };
dma_free_noncoherent(dev, size, vaddr, dma_handle);
WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
&match_data));
}
EXPORT_SYMBOL(dmam_free_noncoherent);
#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
static void dmam_coherent_decl_release(struct device *dev, void *res)
{
dma_release_declared_memory(dev);
}
/**
* dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
* @dev: Device to declare coherent memory for
* @bus_addr: Bus address of coherent memory to be declared
* @device_addr: Device address of coherent memory to be declared
* @size: Size of coherent memory to be declared
* @flags: Flags
*
* Managed dma_declare_coherent_memory().
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags)
{
void *res;
int rc;
res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
if (!res)
return -ENOMEM;
rc = dma_declare_coherent_memory(dev, bus_addr, device_addr, size,
flags);
if (rc == 0)
devres_add(dev, res);
else
devres_free(res);
return rc;
}
EXPORT_SYMBOL(dmam_declare_coherent_memory);
/**
* dmam_release_declared_memory - Managed dma_release_declared_memory().
* @dev: Device to release declared coherent memory for
*
* Managed dmam_release_declared_memory().
*/
void dmam_release_declared_memory(struct device *dev)
{
WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
}
EXPORT_SYMBOL(dmam_release_declared_memory);
#endif
/*
* Create scatter-list for the already allocated DMA buffer.
*/
int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size)
{
struct page *page = virt_to_page(cpu_addr);
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;
}
EXPORT_SYMBOL(dma_common_get_sgtable);
/*
* Create userspace mapping for the DMA-coherent memory.
*/
int dma_common_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_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
unsigned long off = vma->vm_pgoff;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < count && user_count <= (count - off)) {
ret = remap_pfn_range(vma, vma->vm_start,
pfn + off,
user_count << PAGE_SHIFT,
vma->vm_page_prot);
}
#endif /* CONFIG_MMU */
return ret;
}
EXPORT_SYMBOL(dma_common_mmap);