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....@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zh...@oracle.com>
---
Changed since v2:
* move #ifdef folding to previous patch (suggested by Konrad Rzeszutek Wilk)
kernel/dma/swiotlb.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index bedc9f9..a01b83e 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;
--
2.7.4
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
