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Commit adbfa4e6 authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: support DMA_ATTR_NO_KERNEL_MAPPING attribute 



An application that doesn't need kernel mapping of the DMA memory it
allocates may specify DMA_ATTR_NO_KERNEL_MAPPING attribute to allocation
function. Support this attribute and return address of the first struct
page that covers the allocation.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 3f2bbf44

arch/xtensa/kernel/pci-dma.c

+8 −2
Original line number Diff line number Diff line
@@ -116,6 +116,10 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, 


	*handle = phys_to_dma(dev, page_to_phys(page));



	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {

		return page;

	}



#ifdef CONFIG_MMU

	if (PageHighMem(page)) {

		void *p;
@@ -147,7 +151,9 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr, 
	unsigned long addr = (unsigned long)vaddr;

	struct page *page;



	if (addr >= XCHAL_KSEG_BYPASS_VADDR &&

	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {

		page = vaddr;

	} else if (addr >= XCHAL_KSEG_BYPASS_VADDR &&

		   addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE) {

		addr += XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;

		page = virt_to_page(addr);