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* [PATCH 1/3] iommu/tegra: smmu: Remove unnecessary PTC/TLB flush all
@ 2012-11-28 13:52 Hiroshi Doyu
       [not found] ` <1354110775-11810-1-git-send-email-hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
  0 siblings, 1 reply; 5+ messages in thread
From: Hiroshi Doyu @ 2012-11-28 13:52 UTC (permalink / raw)
  To: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	joro-zLv9SwRftAIdnm+yROfE0A
  Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA

smmu_flush_regs() does TLB/PTC flush all when freeing a second level
page table. This isn't necessay at all since each pte entry has been
already maintained by address in the above flush_ptc_and_tlb().

Signed-off-by: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/tegra-smmu.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 4167863..46f5712 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -694,10 +694,8 @@ static void __smmu_iommu_unmap(struct smmu_as *as, dma_addr_t iova)
 	*pte = _PTE_VACANT(iova);
 	FLUSH_CPU_DCACHE(pte, page, sizeof(*pte));
 	flush_ptc_and_tlb(as->smmu, as, iova, pte, page, 0);
-	if (!--(*count)) {
+	if (!--(*count))
 		free_ptbl(as, iova);
-		smmu_flush_regs(as->smmu, 0);
-	}
 }
 
 static void __smmu_iommu_map_pfn(struct smmu_as *as, dma_addr_t iova,
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2012-11-30  5:07 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-11-28 13:52 [PATCH 1/3] iommu/tegra: smmu: Remove unnecessary PTC/TLB flush all Hiroshi Doyu
     [not found] ` <1354110775-11810-1-git-send-email-hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2012-11-28 13:52   ` [PATCH 2/3] iommu/tegra: gart: Move bus_set_iommu after probe for multi arch Hiroshi Doyu
2012-11-28 13:52   ` [PATCH 3/3] iommu/tegra: smmu: " Hiroshi Doyu
     [not found]     ` <1354110775-11810-3-git-send-email-hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2012-11-30  5:07       ` Mark Zhang
2012-11-28 19:40   ` [PATCH 1/3] iommu/tegra: smmu: Remove unnecessary PTC/TLB flush all Joerg Roedel

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