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ARM: dma-mapping: IOMMU allocates pages from atomic_pool with GFP_ATOMIC

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Make use of the same atomic pool as DMA does, and skip a kernel page
mapping which can involve sleep'able operations at allocating a kernel
page table.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
This commit is contained in:
Hiroshi Doyu 2012-08-28 08:13:04 +03:00 committed by Marek Szyprowski
parent 665bad7bb9
commit 479ed93a4b
1 changed files with 36 additions and 0 deletions
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36
arch/arm/mm/dma-mapping.c
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@ -1161,6 +1161,34 @@ static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
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, struct page **pages,
dma_addr_t handle, size_t size)
{
__iommu_remove_mapping(dev, handle, size);
__free_from_pool(page_address(pages[0]), size);
}
static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
{
@ -1171,6 +1199,9 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
*handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);
if (gfp & GFP_ATOMIC)
return __iommu_alloc_atomic(dev, size, handle);
pages = __iommu_alloc_buffer(dev, size, gfp);
if (!pages)
return NULL;
@ -1237,6 +1268,11 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
return;
}
if (__in_atomic_pool(cpu_addr, size)) {
__iommu_free_atomic(dev, pages, handle, size);
return;
}
if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) {
unmap_kernel_range((unsigned long)cpu_addr, size);
vunmap(cpu_addr);