iommu/tegra-smmu: Factor out tegra_smmu_set_pde()

This code is used both when creating a new page directory entry and when
tearing it down, with only the PDE value changing between both cases.

Factor the code out so that it can be reused.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[treding@nvidia.com: make commit message more accurate]
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 74ad1f43265aca614af8078c934f3f24a579359e..2f1481ad4aa51a4dcd175babe5631fc85800a004 100644 (file)
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -495,6 +495,27 @@ static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *de
        }
 }
 
+static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
+                              u32 value)
+{
+       unsigned int pd_index = iova_pd_index(iova);
+       struct tegra_smmu *smmu = as->smmu;
+       u32 *pd = page_address(as->pd);
+       unsigned long offset = pd_index * sizeof(*pd);
+
+       /* Set the page directory entry first */
+       pd[pd_index] = value;
+
+       /* The flush the page directory entry from caches */
+       dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,
+                                        sizeof(*pd), DMA_TO_DEVICE);
+
+       /* And flush the iommu */
+       smmu_flush_ptc(smmu, as->pd_dma, offset);
+       smmu_flush_tlb_section(smmu, as->id, iova);
+       smmu_flush(smmu);
+}
+
 static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova)
 {
        u32 *pt = page_address(pt_page);
@@ -522,7 +543,6 @@ 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);
        unsigned int pde = iova_pd_index(iova);
        struct tegra_smmu *smmu = as->smmu;
 
@@ -550,16 +570,13 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
 
                as->pts[pde] = page;
 
-               pd[pde] = SMMU_MK_PDE(dma, SMMU_PDE_ATTR | SMMU_PDE_NEXT);
-
-               dma_sync_single_range_for_device(smmu->dev, as->pd_dma,
-                                                pde << 2, 4, DMA_TO_DEVICE);
-               smmu_flush_ptc(smmu, as->pd_dma, pde << 2);
-               smmu_flush_tlb_section(smmu, as->id, iova);
-               smmu_flush(smmu);
+               tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR |
+                                                             SMMU_PDE_NEXT));
 
                *dmap = dma;
        } else {
+               u32 *pd = page_address(as->pd);
+
                *dmap = smmu_pde_to_dma(pd[pde]);
        }
 
@@ -575,9 +592,7 @@ static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
 
 static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
 {
-       struct tegra_smmu *smmu = as->smmu;
        unsigned int pde = iova_pd_index(iova);
-       u32 *pd = page_address(as->pd);
        struct page *page = as->pts[pde];
 
        /*
@@ -585,20 +600,12 @@ static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
         * memory page to the system.
         */
        if (--as->count[pde] == 0) {
-               unsigned int offset = pde * sizeof(*pd);
+               struct tegra_smmu *smmu = as->smmu;
+               u32 *pd = page_address(as->pd);
                dma_addr_t pte_dma = smmu_pde_to_dma(pd[pde]);
 
-               /* Clear the page directory entry first */
-               pd[pde] = 0;
-
-               /* Flush the page directory entry */
-               dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,
-                                                sizeof(*pd), DMA_TO_DEVICE);
-               smmu_flush_ptc(smmu, as->pd_dma, offset);
-               smmu_flush_tlb_section(smmu, as->id, iova);
-               smmu_flush(smmu);
+               tegra_smmu_set_pde(as, iova, 0);
 
-               /* Finally, free the page */
                dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
                __free_page(page);
                as->pts[pde] = NULL;