[PATCH v2 02/23] iommu/tegra: Do not use struct page as the handle for pts
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2025-02-14 17:14:26
Also in:
asahi, linux-iommu, linux-patches, linux-riscv, linux-rockchip, linux-samsung-soc, linux-sunxi, linux-tegra
Subsystem:
iommu subsystem, tegra iommu drivers, the rest · Maintainers:
Joerg Roedel, Will Deacon, Thierry Reding, Linus Torvalds
Instead use the virtual address and dma_map_single() like as->pd uses. Introduce a small struct tegra_pt instead of void * to have some clarity what is using this API and add compile safety during the conversion. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/tegra-smmu.c | 74 ++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 35 deletions(-)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index b6e61f5c0861b0..c134647292fb22 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c@@ -52,6 +52,7 @@ struct tegra_smmu { }; struct tegra_pd; +struct tegra_pt; struct tegra_smmu_as { struct iommu_domain domain;
@@ -59,7 +60,7 @@ struct tegra_smmu_as { unsigned int use_count; spinlock_t lock; u32 *count; - struct page **pts; + struct tegra_pt **pts; struct tegra_pd *pd; dma_addr_t pd_dma; unsigned id;
@@ -161,6 +162,10 @@ struct tegra_pd { u32 val[SMMU_NUM_PDE]; }; +struct tegra_pt { + u32 val[SMMU_NUM_PTE]; +}; + static unsigned int iova_pd_index(unsigned long iova) { return (iova >> SMMU_PDE_SHIFT) & (SMMU_NUM_PDE - 1);
@@ -570,11 +575,9 @@ static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova, smmu_flush(smmu); } -static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova) +static u32 *tegra_smmu_pte_offset(struct tegra_pt *pt, unsigned long iova) { - u32 *pt = page_address(pt_page); - - return pt + iova_pt_index(iova); + return &pt->val[iova_pt_index(iova)]; } static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
@@ -582,19 +585,19 @@ static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova, { unsigned int pd_index = iova_pd_index(iova); struct tegra_smmu *smmu = as->smmu; - struct page *pt_page; + struct tegra_pt *pt; - pt_page = as->pts[pd_index]; - if (!pt_page) + pt = as->pts[pd_index]; + if (!pt) return NULL; *dmap = smmu_pde_to_dma(smmu, as->pd->val[pd_index]); - return tegra_smmu_pte_offset(pt_page, iova); + return tegra_smmu_pte_offset(pt, iova); } static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova, - dma_addr_t *dmap, struct page *page) + dma_addr_t *dmap, struct tegra_pt *pt) { unsigned int pde = iova_pd_index(iova); struct tegra_smmu *smmu = as->smmu;
@@ -602,21 +605,21 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova, if (!as->pts[pde]) { dma_addr_t dma; - dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT, - DMA_TO_DEVICE); + dma = dma_map_single(smmu->dev, pt, SMMU_SIZE_PT, + DMA_TO_DEVICE); if (dma_mapping_error(smmu->dev, dma)) { - __iommu_free_pages(page, 0); + iommu_free_page(pt); return NULL; } if (!smmu_dma_addr_valid(smmu, dma)) { - dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT, - DMA_TO_DEVICE); - __iommu_free_pages(page, 0); + dma_unmap_single(smmu->dev, dma, SMMU_SIZE_PT, + DMA_TO_DEVICE); + iommu_free_page(pt); return NULL; } - as->pts[pde] = page; + as->pts[pde] = pt; tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR | SMMU_PDE_NEXT));
@@ -639,7 +642,7 @@ 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) { unsigned int pde = iova_pd_index(iova); - struct page *page = as->pts[pde]; + struct tegra_pt *pt = as->pts[pde]; /* * When no entries in this page table are used anymore, return the
@@ -651,8 +654,9 @@ static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova) tegra_smmu_set_pde(as, iova, 0); - dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE); - __iommu_free_pages(page, 0); + dma_unmap_single(smmu->dev, pte_dma, SMMU_SIZE_PT, + DMA_TO_DEVICE); + iommu_free_page(pt); as->pts[pde] = NULL; } }
@@ -672,16 +676,16 @@ static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova, smmu_flush(smmu); } -static struct page *as_get_pde_page(struct tegra_smmu_as *as, - unsigned long iova, gfp_t gfp, - unsigned long *flags) +static struct tegra_pt *as_get_pde_page(struct tegra_smmu_as *as, + unsigned long iova, gfp_t gfp, + unsigned long *flags) { unsigned int pde = iova_pd_index(iova); - struct page *page = as->pts[pde]; + struct tegra_pt *pt = as->pts[pde]; /* at first check whether allocation needs to be done at all */ - if (page) - return page; + if (pt) + return pt; /* * In order to prevent exhaustion of the atomic memory pool, we
@@ -691,7 +695,7 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as, if (gfpflags_allow_blocking(gfp)) spin_unlock_irqrestore(&as->lock, *flags); - page = __iommu_alloc_pages(gfp | __GFP_DMA, 0); + pt = iommu_alloc_page(gfp | __GFP_DMA); if (gfpflags_allow_blocking(gfp)) spin_lock_irqsave(&as->lock, *flags);
@@ -702,13 +706,13 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as, * if allocation succeeded and the allocation failure isn't fatal. */ if (as->pts[pde]) { - if (page) - __iommu_free_pages(page, 0); + if (pt) + iommu_free_page(pt); - page = as->pts[pde]; + pt = as->pts[pde]; } - return page; + return pt; } static int
@@ -718,15 +722,15 @@ __tegra_smmu_map(struct iommu_domain *domain, unsigned long iova, { struct tegra_smmu_as *as = to_smmu_as(domain); dma_addr_t pte_dma; - struct page *page; + struct tegra_pt *pt; u32 pte_attrs; u32 *pte; - page = as_get_pde_page(as, iova, gfp, flags); - if (!page) + pt = as_get_pde_page(as, iova, gfp, flags); + if (!pt) return -ENOMEM; - pte = as_get_pte(as, iova, &pte_dma, page); + pte = as_get_pte(as, iova, &pte_dma, pt); if (!pte) return -ENOMEM;
--
2.43.0