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authorDongli Zhang <dongli.zhang@oracle.com>2019-04-12 14:38:26 +0300
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2019-04-13 02:44:46 +0300
commit53b29c336830db48ad3dc737f88b8c065b1f0851 (patch)
tree005f8ea4c317a99f2b583c2fa3b9db21f4eeb0b2 /kernel/dma
parent83ca259489409a1fe8a83dad83a82f32174d4f31 (diff)
downloadlinux-53b29c336830db48ad3dc737f88b8c065b1f0851.tar.xz
swiotlb: save io_tlb_used to local variable before leaving critical section
When swiotlb is full, the kernel would print io_tlb_used. However, the result might be inaccurate at that time because we have left the critical section protected by spinlock. Therefore, we backup the io_tlb_used into local variable before leaving critical section. Fixes: 83ca25948940 ("swiotlb: dump used and total slots when swiotlb buffer is full") Suggested-by: HÃ¥kon Bugge <haakon.bugge@oracle.com> Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/swiotlb.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 82c767374c70..38d57218809c 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -445,6 +445,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
unsigned long mask;
unsigned long offset_slots;
unsigned long max_slots;
+ unsigned long tmp_io_tlb_used;
if (no_iotlb_memory)
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
@@ -531,10 +532,12 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
} while (index != wrap);
not_found:
+ tmp_io_tlb_used = io_tlb_used;
+
spin_unlock_irqrestore(&io_tlb_lock, flags);
if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
- dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu, used %lu\n",
- size, io_tlb_nslabs, io_tlb_used);
+ dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
+ size, io_tlb_nslabs, tmp_io_tlb_used);
return DMA_MAPPING_ERROR;
found:
io_tlb_used += nslots;