Commit 60513ed0 authored Jan 18, 2019 by Dongli Zhang Committed by Konrad Rzeszutek Wilk Feb 12, 2019

swiotlb: checking whether swiotlb buffer is full with io_tlb_used



This patch uses io_tlb_used to help check whether swiotlb buffer is full.
io_tlb_used is no longer used for only debugfs. It is also used to help
optimize swiotlb_tbl_map_single().

Suggested-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

parent 71602fe6

kernel/dma/swiotlb.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -483,6 +483,10 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
		* request and allocate a buffer from that IO TLB pool.
		*/
		spin_lock_irqsave(&io_tlb_lock, flags);

		if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
		goto not_found;

		index = ALIGN(io_tlb_index, stride);
		if (index >= io_tlb_nslabs)
		index = 0;

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