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

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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: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Fabio M. De Francesco 2022-09-01 15:29:06 +02:00 committed by Christoph Hellwig
parent 521a547ced
commit 1d61261bfe
1 changed files with 4 additions and 6 deletions
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10
kernel/dma/swiotlb.c
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@ -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;