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dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods 

This will allow IOMMU drivers to allocate non-contigous memory and
return a vmapped virtual address.

Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Christoph Hellwig 2020-09-01 13:59:45 +02:00
parent efa70f2fdc
commit de7cf91776
2 changed files with 32 additions and 6 deletions
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5
include/linux/dma-mapping.h
View File

@ -74,6 +74,11 @@ struct dma_map_ops {
gfp_t gfp);
void (*free_pages)(struct device *dev, size_t size, struct page *vaddr,
dma_addr_t dma_handle, enum dma_data_direction dir);
void* (*alloc_noncoherent)(struct device *dev, size_t size,
dma_addr_t *dma_handle, enum dma_data_direction dir,
gfp_t gfp);
void (*free_noncoherent)(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, enum dma_data_direction dir);
int (*mmap)(struct device *, struct vm_area_struct *,
void *, dma_addr_t, size_t,
unsigned long attrs);

33
kernel/dma/mapping.c
View File

@ -513,19 +513,40 @@ 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;
const struct dma_map_ops *ops = get_dma_ops(dev);
void *vaddr;
page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
if (!page)
return NULL;
return page_address(page);
if (!ops || !ops->alloc_noncoherent) {
struct page *page;
page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
if (!page)
return NULL;
return page_address(page);
}
size = PAGE_ALIGN(size);
vaddr = ops->alloc_noncoherent(dev, size, dma_handle, dir, gfp);
if (vaddr)
debug_dma_map_page(dev, virt_to_page(vaddr), 0, size, dir,
*dma_handle);
return vaddr;
}
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);
const struct dma_map_ops *ops = get_dma_ops(dev);
if (!ops || !ops->free_noncoherent) {
dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
return;
}
size = PAGE_ALIGN(size);
debug_dma_unmap_page(dev, dma_handle, size, dir);
ops->free_noncoherent(dev, size, vaddr, dma_handle, dir);
}
EXPORT_SYMBOL_GPL(dma_free_noncoherent);