* [PATCH] iommu/amd: Free already flushed ring-buffer entries before full-check
@ 2017-06-22 10:16 Joerg Roedel
0 siblings, 0 replies; only message in thread
From: Joerg Roedel @ 2017-06-22 10:16 UTC (permalink / raw)
To: iommu; +Cc: linux-kernel, Joerg Roedel
From: Joerg Roedel <jroedel@suse.de>
To benefit from IOTLB flushes on other CPUs we have to free
the already flushed IOVAs from the ring-buffer before we do
the queue_ring_full() check.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/amd_iommu.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 623ab53..34a6cac 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1883,14 +1883,20 @@ static void queue_add(struct dma_ops_domain *dom,
spin_lock_irqsave(&queue->lock, flags);
/*
+ * First remove the enries from the ring-buffer that are already
+ * flushed to make the below queue_ring_full() check less likely
+ */
+ queue_ring_free_flushed(dom, queue);
+
+ /*
* When ring-queue is full, flush the entries from the IOTLB so
* that we can free all entries with queue_ring_free_flushed()
* below.
*/
- if (queue_ring_full(queue))
+ if (queue_ring_full(queue)) {
dma_ops_domain_flush_tlb(dom);
-
- queue_ring_free_flushed(dom, queue);
+ queue_ring_free_flushed(dom, queue);
+ }
idx = queue_ring_add(queue);
--
2.7.4
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2017-06-22 10:17 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-06-22 10:16 [PATCH] iommu/amd: Free already flushed ring-buffer entries before full-check Joerg Roedel
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).