[RFC PATCH v2 38/58] iommu/io-pgtable-arm: Add post table walker callback

[Mostafa Saleh <smostafa@google.com>]

Add a callback for postable, this would be used by pKVM to
cleanup tables next.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
---
 drivers/iommu/io-pgtable-arm-common.c | 15 ++++++++++++++-
 include/linux/io-pgtable-arm.h        |  2 ++
 include/linux/io-pgtable.h            |  2 ++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-common.c b/drivers/iommu/io-pgtable-arm-common.c
index 4fc0b03494e3..076240eaec19 100644
--- a/drivers/iommu/io-pgtable-arm-common.c
+++ b/drivers/iommu/io-pgtable-arm-common.c
@@ -523,6 +523,13 @@ static int visit_pgtable_walk(struct io_pgtable_walk_data *walk_data, int lvl,
 	return 0;
 }
 
+static void visit_pgtable_post_table(struct arm_lpae_io_pgtable_walk_data *data,
+				     arm_lpae_iopte *ptep, int lvl)
+{
+	if (data->visit_post_table)
+		data->visit_post_table(data, ptep, lvl);
+}
+
 static int arm_lpae_pgtable_walk(struct io_pgtable_ops *ops, unsigned long iova,
 				 size_t size, struct io_pgtable_walk_common *walker)
 {
@@ -530,6 +537,7 @@ static int arm_lpae_pgtable_walk(struct io_pgtable_ops *ops, unsigned long iova,
 	struct io_pgtable_walk_data walk_data = {
 		.data = walker,
 		.visit = visit_pgtable_walk,
+		.visit_post_table = visit_pgtable_post_table,
 		.addr = iova,
 		.end = iova + size,
 	};
@@ -562,7 +570,12 @@ static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
 	}
 
 	ptep = iopte_deref(pte, data);
-	return __arm_lpae_iopte_walk(data, walk_data, ptep, lvl + 1);
+	ret = __arm_lpae_iopte_walk(data, walk_data, ptep, lvl + 1);
+
+	if (walk_data->visit_post_table)
+		walk_data->visit_post_table(data, ptep, lvl);
+
+	return ret;
 }
 
 static int __arm_lpae_iopte_walk(struct arm_lpae_io_pgtable *data,
diff --git a/include/linux/io-pgtable-arm.h b/include/linux/io-pgtable-arm.h
index 9e5878c37d78..c00eb0cb7e43 100644
--- a/include/linux/io-pgtable-arm.h
+++ b/include/linux/io-pgtable-arm.h
@@ -21,6 +21,8 @@ struct io_pgtable_walk_data {
 	struct io_pgtable_walk_common	*data;
 	int (*visit)(struct io_pgtable_walk_data *walk_data, int lvl,
 		     arm_lpae_iopte *ptep, size_t size);
+	void (*visit_post_table)(struct arm_lpae_io_pgtable_walk_data *data,
+				 arm_lpae_iopte *ptep, int lvl);
 	unsigned long			flags;
 	u64				addr;
 	const u64			end;
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index da50e17b0177..86226571cdb8 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -193,6 +193,8 @@ struct arm_lpae_io_pgtable_walk_data {
 	u64 ptes[4];
 	int level;
 	void *cookie;
+	void (*visit_post_table)(struct arm_lpae_io_pgtable_walk_data *data,
+				 arm_lpae_iopte *ptep, int lvl);
 };
 
 /**
-- 
2.47.0.338.g60cca15819-goog