Commit 1d61261b authored by Fabio M. De Francesco's avatar Fabio M. De Francesco Committed by Christoph Hellwig
Browse files

swiotlb: replace kmap_atomic() with memcpy_{from,to}_page() 



The use of kmap_atomic() is being deprecated in favor of
kmap_local_page(), which can also be used in atomic context (including
interrupts).

Replace kmap_atomic() with kmap_local_page(). Instead of open coding
mapping, memcpy(), and un-mapping, use the memcpy_{from,to}_page() helper.

Suggested-by: default avatarIra Weiny <ira.weiny@intel.com>
Signed-off-by: default avatarFabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 521a547c

kernel/dma/swiotlb.c

+4 −6
Original line number Diff line number Diff line
@@ -545,9 +545,8 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size 
	}



	if (PageHighMem(pfn_to_page(pfn))) {

		/* The buffer does not have a mapping.  Map it in and copy */

		unsigned int offset = orig_addr & ~PAGE_MASK;

		char *buffer;

		struct page *page;

		unsigned int sz = 0;

		unsigned long flags;
@@ -555,12 +554,11 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size 
			sz = min_t(size_t, PAGE_SIZE - offset, size);



			local_irq_save(flags);

			buffer = kmap_atomic(pfn_to_page(pfn));

			page = pfn_to_page(pfn);

			if (dir == DMA_TO_DEVICE)

				memcpy(vaddr, buffer + offset, sz);

				memcpy_from_page(vaddr, page, offset, sz);

			else

				memcpy(buffer + offset, vaddr, sz);

			kunmap_atomic(buffer);

				memcpy_to_page(page, offset, vaddr, sz);

			local_irq_restore(flags);



			size -= sz;