From: Dongli Zhang <dongli.zhang@oracle.com>
To: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org
Cc: konrad.wilk@oracle.com, hch@lst.de, m.szyprowski@samsung.com,
robin.murphy@arm.com, joe.jin@oracle.com,
dongli.zhang@oracle.com
Subject: [PATCH v3 3/3] swiotlb: checking whether swiotlb buffer is full with io_tlb_used
Date: Fri, 18 Jan 2019 15:10:28 +0800 [thread overview]
Message-ID: <1547795428-10595-3-git-send-email-dongli.zhang@oracle.com> (raw)
In-Reply-To: <1547795428-10595-1-git-send-email-dongli.zhang@oracle.com>
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>
---
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
next prev parent reply other threads:[~2019-01-18 7:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-18 7:10 [PATCH v3 1/3] swiotlb: fix comment on swiotlb_bounce() Dongli Zhang
2019-01-18 7:10 ` [PATCH v3 2/3] swiotlb: add debugfs to track swiotlb buffer usage Dongli Zhang
2019-01-18 7:10 ` Dongli Zhang [this message]
2019-02-12 18:47 ` [PATCH v3 1/3] swiotlb: fix comment on swiotlb_bounce() Konrad Rzeszutek Wilk
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