From: Rob Clark <[email protected]> Add an io-pgtable method to walk the pgtable returning the raw PTEs that would be traversed for a given iova access.
Signed-off-by: Rob Clark <[email protected]> --- drivers/iommu/io-pgtable-arm.c | 26 ++++++++++++++++++++++++++ include/linux/io-pgtable.h | 15 +++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 88b128c77893..c51c48851f9f 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -762,6 +762,31 @@ static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops, return iopte_to_paddr(d.pte, data) | iova; } +static int visit_pgtable_walk(struct io_pgtable_walk_data *walk_data, int lvl, + arm_lpae_iopte *ptep, size_t size) +{ + struct arm_lpae_io_pgtable_walk_data *data = walk_data->data; + data->ptes[lvl] = *ptep; + data->level = lvl + 1; + return 0; +} + +static int arm_lpae_pgtable_walk(struct io_pgtable_ops *ops, unsigned long iova, + void *wd) +{ + struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops); + struct io_pgtable_walk_data walk_data = { + .data = wd, + .visit = visit_pgtable_walk, + .addr = iova, + .end = iova + 1, + }; + + ((struct arm_lpae_io_pgtable_walk_data *)wd)->level = 0; + + return __arm_lpae_iopte_walk(data, &walk_data, data->pgd, data->start_level); +} + static int io_pgtable_visit(struct arm_lpae_io_pgtable *data, struct io_pgtable_walk_data *walk_data, arm_lpae_iopte *ptep, int lvl) @@ -937,6 +962,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) .unmap_pages = arm_lpae_unmap_pages, .iova_to_phys = arm_lpae_iova_to_phys, .read_and_clear_dirty = arm_lpae_read_and_clear_dirty, + .pgtable_walk = arm_lpae_pgtable_walk, }; return data; diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h index b1ecfc3cd5bc..d7bfbf351975 100644 --- a/include/linux/io-pgtable.h +++ b/include/linux/io-pgtable.h @@ -178,12 +178,26 @@ struct io_pgtable_cfg { }; }; +/** + * struct arm_lpae_io_pgtable_walk_data - information from a pgtable walk + * + * @ptes: The recorded PTE values from the walk + * @level: The level of the last PTE + * + * @level also specifies the last valid index in @ptes + */ +struct arm_lpae_io_pgtable_walk_data { + u64 ptes[4]; + int level; +}; + /** * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers. * * @map_pages: Map a physically contiguous range of pages of the same size. * @unmap_pages: Unmap a range of virtually contiguous pages of the same size. * @iova_to_phys: Translate iova to physical address. + * @pgtable_walk: (optional) Perform a page table walk for a given iova. * * These functions map directly onto the iommu_ops member functions with * the same names. @@ -197,6 +211,7 @@ struct io_pgtable_ops { struct iommu_iotlb_gather *gather); phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops, unsigned long iova); + int (*pgtable_walk)(struct io_pgtable_ops *ops, unsigned long iova, void *wd); int (*read_and_clear_dirty)(struct io_pgtable_ops *ops, unsigned long iova, size_t size, unsigned long flags, -- 2.47.1
