Commit 2fc0ac18 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Joerg Roedel
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iommu/tegra: gart: Optimize mapping / unmapping performance 



Currently GART writes one page entry at a time. More optimal would be to
aggregate the writes and flush BUS buffer in the end, this gives map/unmap
10-40% performance boost (depending on size of mapping) in comparison to
flushing after each page entry update.

Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
Acked-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 1d7ae53b

drivers/iommu/tegra-gart.c

+10 −2
Original line number Diff line number Diff line
@@ -290,7 +290,6 @@ static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova, 
		}

	}

	gart_set_pte(gart, iova, GART_PTE(pfn));

	FLUSH_GART_REGS(gart);

	spin_unlock_irqrestore(&gart->pte_lock, flags);

	return 0;

}
@@ -307,7 +306,6 @@ static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova, 


	spin_lock_irqsave(&gart->pte_lock, flags);

	gart_set_pte(gart, iova, 0);

	FLUSH_GART_REGS(gart);

	spin_unlock_irqrestore(&gart->pte_lock, flags);

	return bytes;

}
@@ -373,6 +371,14 @@ static int gart_iommu_of_xlate(struct device *dev, 
	return 0;

}



static void gart_iommu_sync(struct iommu_domain *domain)

{

	struct gart_domain *gart_domain = to_gart_domain(domain);

	struct gart_device *gart = gart_domain->gart;



	FLUSH_GART_REGS(gart);

}



static const struct iommu_ops gart_iommu_ops = {

	.capable	= gart_iommu_capable,

	.domain_alloc	= gart_iommu_domain_alloc,
@@ -387,6 +393,8 @@ static const struct iommu_ops gart_iommu_ops = { 
	.iova_to_phys	= gart_iommu_iova_to_phys,

	.pgsize_bitmap	= GART_IOMMU_PGSIZES,

	.of_xlate	= gart_iommu_of_xlate,

	.iotlb_sync_map	= gart_iommu_sync,

	.iotlb_sync	= gart_iommu_sync,

};



static int tegra_gart_suspend(struct device *dev)

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