linux-kernel - [PATCH 8/9] iommu/amd: Optimize amd_iommu_iova_to_phys for new fetch

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Date:	Wed,  1 Apr 2015 14:58:51 +0200
From:	Joerg Roedel <joro@...tes.org>
To:	iommu@...ts.linux-foundation.org
Cc:	Suravee.Suthikulpanit@....com, linux-kernel@...r.kernel.org,
	Joerg Roedel <jroedel@...e.de>
Subject: [PATCH 8/9] iommu/amd: Optimize amd_iommu_iova_to_phys for new fetch_pte interface

From: Joerg Roedel <jroedel@...e.de>

Now that fetch_pte returns the page-size of the pte, this
function can be optimized too.

Signed-off-by: Joerg Roedel <jroedel@...e.de>
---
 drivers/iommu/amd_iommu.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index f97441b..7a00e5d 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3375,7 +3375,6 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
 {
 	struct protection_domain *domain = dom->priv;
 	unsigned long offset_mask, pte_pgsize;
-	phys_addr_t paddr;
 	u64 *pte, __pte;
 
 	if (domain->mode == PAGE_MODE_NONE)
@@ -3386,15 +3385,10 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
 	if (!pte || !IOMMU_PTE_PRESENT(*pte))
 		return 0;
 
-	if (PM_PTE_LEVEL(*pte) == 0)
-		offset_mask = PAGE_SIZE - 1;
-	else
-		offset_mask = PTE_PAGE_SIZE(*pte) - 1;
-
-	__pte = *pte & PM_ADDR_MASK;
-	paddr = (__pte & ~offset_mask) | (iova & offset_mask);
+	offset_mask = pte_pgsize - 1;
+	__pte	    = *pte & PM_ADDR_MASK;
 
-	return paddr;
+	return (__pte & ~offset_mask) | (iova & offset_mask);
 }
 
 static bool amd_iommu_capable(enum iommu_cap cap)
-- 
1.9.1

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