Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 479ed93a authored by Hiroshi Doyu's avatar Hiroshi Doyu Committed by Marek Szyprowski
Browse files

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



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: default avatarHiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
parent 665bad7b

arch/arm/mm/dma-mapping.c

+36 −0
Original line number Diff line number Diff line
@@ -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);