From 60513ed06a41049768a6875229b025b6e726e148 Mon Sep 17 00:00:00 2001 From: Dongli Zhang Date: Fri, 18 Jan 2019 15:10:28 +0800 Subject: 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 Signed-off-by: Dongli Zhang Signed-off-by: Konrad Rzeszutek Wilk --- kernel/dma/swiotlb.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel/dma') diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index bedc9f945836..a01b83e95a2a 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -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; -- cgit v1.2.3