Commit bfd56cd6 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: support highmem in the generic remap allocator 



By using __dma_direct_alloc_pages we can deal entirely with struct page
instead of having to derive a kernel virtual address.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
parent 0c3b3171

kernel/dma/remap.c

+7 −7
Original line number Diff line number Diff line
@@ -196,7 +196,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 
		gfp_t flags, unsigned long attrs)

{

	struct page *page = NULL;

	void *ret, *kaddr;

	void *ret;



	size = PAGE_ALIGN(size);
@@ -208,10 +208,9 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 
		return ret;

	}



	kaddr = dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs);

	if (!kaddr)

	page = __dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs);

	if (!page)

		return NULL;

	page = virt_to_page(kaddr);



	/* remove any dirty cache lines on the kernel alias */

	arch_dma_prep_coherent(page, size);
@@ -221,7 +220,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 
			arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs),

			__builtin_return_address(0));

	if (!ret)

		dma_direct_free_pages(dev, size, kaddr, *dma_handle, attrs);

		__dma_direct_free_pages(dev, size, page);

	return ret;

}
@@ -229,10 +228,11 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr, 
		dma_addr_t dma_handle, unsigned long attrs)

{

	if (!dma_free_from_pool(vaddr, PAGE_ALIGN(size))) {

		void *kaddr = phys_to_virt(dma_to_phys(dev, dma_handle));

		phys_addr_t phys = dma_to_phys(dev, dma_handle);

		struct page *page = pfn_to_page(__phys_to_pfn(phys));



		vunmap(vaddr);

		dma_direct_free_pages(dev, size, kaddr, dma_handle, attrs);

		__dma_direct_free_pages(dev, size, page);

	}

}