From 7ffc6f066eb73b07a0ef7c94d05107aef271ac21 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 6 Aug 2015 14:56:39 +0200 Subject: [PATCH] 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 [treding@nvidia.com: extract and write commit message] Signed-off-by: Thierry Reding --- drivers/iommu/tegra-smmu.c | 17 +++++++++++------ 1 file 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);