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dma-mapping: support non-coherent devices in dma_common_get_sgtable 

We can use the arch_dma_coherent_to_pfn hook to provide a ->get_sgtable
implementation.  Note that this isn't an endorsement of this interface
(which is a horrible bad idea), but it is required to move arm64 over
to the generic code without a loss of functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
hifive-unleashed-5.1
Christoph Hellwig 2018-08-23 09:39:38 +02:00
parent 58b0440663
commit 9406a49fd1
3 changed files with 21 additions and 11 deletions
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2
drivers/xen/swiotlb-xen.c
View File

@ -689,7 +689,7 @@ xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
handle, size, attrs);
}
#endif
return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size);
return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size, attrs);
}
static int xen_swiotlb_mapping_error(struct device *dev, dma_addr_t dma_addr)

7
include/linux/dma-mapping.h
View File

@ -483,8 +483,8 @@ dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
int
dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size);
dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr,
dma_addr_t dma_addr, size_t size, unsigned long attrs);
static inline int
dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr,
@ -496,7 +496,8 @@ dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr,
if (ops->get_sgtable)
return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
attrs);
return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size);
return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
attrs);
}
#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)

23
kernel/dma/mapping.c
View File

@ -202,17 +202,26 @@ EXPORT_SYMBOL(dmam_release_declared_memory);
* 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)
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
struct page *page = virt_to_page(cpu_addr);
struct page *page;
int ret;
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (unlikely(ret))
return ret;
if (!dev_is_dma_coherent(dev)) {
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
return -ENXIO;
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
return 0;
page = pfn_to_page(arch_dma_coherent_to_pfn(dev, cpu_addr,
dma_addr));
} else {
page = virt_to_page(cpu_addr);
}
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (!ret)
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
return ret;
}
EXPORT_SYMBOL(dma_common_get_sgtable);