From: Dongli Zhang Date: Tue, 16 Apr 2019 23:49:20 +0000 (+0800) Subject: swiotlb: save io_tlb_used to local variable before leaving critical section X-Git-Tag: v4.1.12-124.31.3~164 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1c64a805c49b69398b06f8bd3cbf91f6041ce404;p=users%2Fjedix%2Flinux-maple.git 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: Håkon Bugge Signed-off-by: Dongli Zhang Signed-off-by: Konrad Rzeszutek Wilk Orabug: 29637525 (cherry picked from commit 53b29c336830db48ad3dc737f88b8c065b1f0851) Signed-off-by: Brian Maly Conflicts: kernel/dma/swiotlb.c does not exist. Signed-off-by: Dongli Zhang Reviewed-By: Joe Jin Signed-off-by: Brian Maly --- diff --git a/lib/swiotlb.c b/lib/swiotlb.c index d08ce286e1d2..6ef2098cbd89 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -442,6 +442,7 @@ 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"); @@ -524,10 +525,12 @@ 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 (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 SWIOTLB_MAP_ERROR; found: io_tlb_used += nslots;