xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dma-mapping: add a new dma_alloc_pages API

Browse Source 
This API is the equivalent of alloc_pages, except that the returned memory
is guaranteed to be DMA addressable by the passed in device.  The
implementation will also be used to provide a more sensible replacement
for DMA_ATTR_NON_CONSISTENT flag.

Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages
as its backend.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
This commit is contained in:
Christoph Hellwig
2020-09-01 13:34:33 +02:00
parent 5a84292271
commit efa70f2fdc
23 changed files with 206 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
kernel/dma/mapping.c
View File

@@ -341,9 +341,7 @@ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
{
if (force_dma_unencrypted(dev))
prot = pgprot_decrypted(prot);
if (dev_is_dma_coherent(dev) ||
(IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
(attrs & DMA_ATTR_NON_CONSISTENT)))
if (dev_is_dma_coherent(dev))
return prot;
#ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
if (attrs & DMA_ATTR_WRITE_COMBINE)
@@ -472,6 +470,65 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
}
EXPORT_SYMBOL(dma_free_attrs);
struct page *dma_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
struct page *page;
if (WARN_ON_ONCE(!dev->coherent_dma_mask))
return NULL;
if (WARN_ON_ONCE(gfp & (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)))
return NULL;
size = PAGE_ALIGN(size);
if (dma_alloc_direct(dev, ops))
page = dma_direct_alloc_pages(dev, size, dma_handle, dir, gfp);
else if (ops->alloc_pages)
page = ops->alloc_pages(dev, size, dma_handle, dir, gfp);
else
return NULL;
debug_dma_map_page(dev, page, 0, size, dir, *dma_handle);
return page;
}
EXPORT_SYMBOL_GPL(dma_alloc_pages);
void dma_free_pages(struct device *dev, size_t size, struct page *page,
dma_addr_t dma_handle, enum dma_data_direction dir)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
size = PAGE_ALIGN(size);
debug_dma_unmap_page(dev, dma_handle, size, dir);
if (dma_alloc_direct(dev, ops))
dma_direct_free_pages(dev, size, page, dma_handle, dir);
else if (ops->free_pages)
ops->free_pages(dev, size, page, dma_handle, dir);
}
EXPORT_SYMBOL_GPL(dma_free_pages);
void *dma_alloc_noncoherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
{
struct page *page;
page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
if (!page)
return NULL;
return page_address(page);
}
EXPORT_SYMBOL_GPL(dma_alloc_noncoherent);
void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, enum dma_data_direction dir)
{
dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
}
EXPORT_SYMBOL_GPL(dma_free_noncoherent);
int dma_supported(struct device *dev, u64 mask)
{
const struct dma_map_ops *ops = get_dma_ops(dev);