diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index abc48c76c770c87c45f59e134a97bb0705f6d2bd..275bf9bdf5493526a1f0c44fe4f58a5bea8be36a 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -801,6 +801,83 @@ static size_t arm_lpae_split_block(struct io_pgtable_ops *ops, return __arm_lpae_split_block(data, iova, size, lvl, ptep); } +static size_t __arm_lpae_merge_page(struct arm_lpae_io_pgtable *data, + unsigned long iova, phys_addr_t paddr, + size_t size, int lvl, arm_lpae_iopte *ptep, + arm_lpae_iopte prot) +{ + arm_lpae_iopte pte, *tablep; + struct io_pgtable *iop = &data->iop; + struct io_pgtable_cfg *cfg = &data->iop.cfg; + + if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS)) + return 0; + + ptep += ARM_LPAE_LVL_IDX(iova, lvl, data); + pte = READ_ONCE(*ptep); + if (WARN_ON(!pte)) + return 0; + + if (size == ARM_LPAE_BLOCK_SIZE(lvl, data)) { + if (iopte_leaf(pte, lvl, iop->fmt)) + return size; + + /* Race does not exist */ + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_BBML1) { + prot |= ARM_LPAE_PTE_NT; + __arm_lpae_init_pte(data, paddr, prot, lvl, ptep); + io_pgtable_tlb_flush_walk(iop, iova, size, + ARM_LPAE_GRANULE(data)); + + prot &= ~(ARM_LPAE_PTE_NT); + __arm_lpae_init_pte(data, paddr, prot, lvl, ptep); + } else { + __arm_lpae_init_pte(data, paddr, prot, lvl, ptep); + } + + tablep = iopte_deref(pte, data); + __arm_lpae_free_pgtable(data, lvl + 1, tablep); + return size; + } else if (iopte_leaf(pte, lvl, iop->fmt)) { + /* The size is too small, already merged */ + return size; + } + + /* Keep on walkin */ + ptep = iopte_deref(pte, data); + return __arm_lpae_merge_page(data, iova, paddr, size, lvl + 1, ptep, prot); +} + +static size_t arm_lpae_merge_page(struct io_pgtable_ops *ops, unsigned long iova, + phys_addr_t paddr, size_t size, int iommu_prot) +{ + struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops); + struct io_pgtable_cfg *cfg = &data->iop.cfg; + arm_lpae_iopte *ptep = data->pgd; + int lvl = data->start_level; + arm_lpae_iopte prot; + long iaext = (s64)iova >> cfg->ias; + + if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size)) + return 0; + + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1) + iaext = ~iaext; + if (WARN_ON(iaext || paddr >> cfg->oas)) + return 0; + + /* If no access, then nothing to do */ + if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE))) + return size; + + /* If it is smallest granule, then nothing to do */ + if (size == ARM_LPAE_BLOCK_SIZE(ARM_LPAE_MAX_LEVELS - 1, data)) + return size; + + prot = arm_lpae_prot_to_pte(data, iommu_prot); + return __arm_lpae_merge_page(data, iova, paddr, size, lvl, ptep, prot); +} + static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg) { unsigned long granule, page_sizes; @@ -880,6 +957,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) .unmap = arm_lpae_unmap, .iova_to_phys = arm_lpae_iova_to_phys, .split_block = arm_lpae_split_block, + .merge_page = arm_lpae_merge_page, }; return data; diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h index 8a8711baa4f17838c59d7d54084be15fc9cdb85e..caa3436cf09c463750fedd307f642a1c663ada37 100644 --- a/include/linux/io-pgtable.h +++ b/include/linux/io-pgtable.h @@ -169,6 +169,8 @@ struct io_pgtable_ops { unsigned long iova); size_t (*split_block)(struct io_pgtable_ops *ops, unsigned long iova, size_t size); + size_t (*merge_page)(struct io_pgtable_ops *ops, unsigned long iova, + phys_addr_t phys, size_t size, int prot); }; /**