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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-08-06 14:56:39 +0200
committerThierry Reding <treding@nvidia.com>2015-08-13 16:06:43 +0200
commit7ffc6f066eb73b07a0ef7c94d05107aef271ac21 (patch)
tree976b618114e7527e91d1c234bcd710ca6afec72e /drivers/iommu
parentiommu/tegra-smmu: Use __GFP_ZERO to allocate zeroed pages (diff)
downloadlinux-7ffc6f066eb73b07a0ef7c94d05107aef271ac21.tar.xz
linux-7ffc6f066eb73b07a0ef7c94d05107aef271ac21.zip
iommu/tegra-smmu: Extract tegra_smmu_pte_get_use()
Extract the use count reference accounting into a separate function and separate it from allocating the PTE. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> [treding@nvidia.com: extract and write commit message] Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/tegra-smmu.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 27d31f62a822..74ad1f43265a 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -522,7 +522,7 @@ static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
dma_addr_t *dmap)
{
- u32 *pd = page_address(as->pd), *pt;
+ u32 *pd = page_address(as->pd);
unsigned int pde = iova_pd_index(iova);
struct tegra_smmu *smmu = as->smmu;
@@ -563,13 +563,14 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
*dmap = smmu_pde_to_dma(pd[pde]);
}
- pt = tegra_smmu_pte_offset(as->pts[pde], iova);
+ return tegra_smmu_pte_offset(as->pts[pde], iova);
+}
- /* Keep track of entries in this page table. */
- if (*pt == 0)
- as->count[pde]++;
+static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
+{
+ unsigned int pd_index = iova_pd_index(iova);
- return pt;
+ as->count[pd_index]++;
}
static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
@@ -630,6 +631,10 @@ static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
if (!pte)
return -ENOMEM;
+ /* If we aren't overwriting a pre-existing entry, increment use */
+ if (*pte == 0)
+ tegra_smmu_pte_get_use(as, iova);
+
tegra_smmu_set_pte(as, iova, pte, pte_dma,
__phys_to_pfn(paddr) | SMMU_PTE_ATTR);