From: Rob Clark <robdclark@xxxxxxxxxxxx>
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 <robdclark@xxxxxxxxxxxx>
---
drivers/iommu/io-pgtable-arm.c | 25 +++++++++++++++++++++++++
include/linux/io-pgtable.h | 15 +++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 88b128c77893..6739e1fa54ec 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -762,6 +762,30 @@ 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[data->level++] = *ptep;
+ 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 +961,7 @@ 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,
--
2.47.0
