[PATCH v4 21/24] iommu/arm-smmu-v3: Move arm_smmu_invs_for_each_entry to header

[Nicolin Chen]

A subsequent change will use this helper in a lockless context. Since this
this is a macro, move it to the header file so other functions can use it.

Also, add READ_ONCE to invs->num_invs for lockless use.

Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 28 +++++++++++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 28 ---------------------
 2 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 2074814534fef..b5ace01c05a5d 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -803,6 +803,34 @@ struct arm_smmu_invs {
 	struct arm_smmu_inv inv[] __counted_by(max_invs);
 };
 
+/* Invalidation array manipulation functions */
+static inline struct arm_smmu_inv *
+arm_smmu_invs_iter_next(struct arm_smmu_invs *invs, size_t next, size_t *idx)
+{
+	while (true) {
+		if (next >= READ_ONCE(invs->num_invs)) {
+			*idx = next;
+			return NULL;
+		}
+		if (!READ_ONCE(invs->inv[next].users)) {
+			next++;
+			continue;
+		}
+		*idx = next;
+		return &invs->inv[next];
+	}
+}
+
+/**
+ * arm_smmu_invs_for_each_entry - Iterate over all non-trash entries in invs
+ * @invs: the base invalidation array
+ * @idx: a stack variable of 'size_t', to store the array index
+ * @cur: a stack variable of 'struct arm_smmu_inv *'
+ */
+#define arm_smmu_invs_for_each_entry(invs, idx, cur)                           \
+	for (cur = arm_smmu_invs_iter_next(invs, 0, &(idx)); cur;              \
+	     cur = arm_smmu_invs_iter_next(invs, idx + 1, &(idx)))
+
 static inline struct arm_smmu_invs *arm_smmu_invs_alloc(size_t num_invs)
 {
 	struct arm_smmu_invs *new_invs;
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 4f2b23b1e8163..c95297acf2cfe 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -979,34 +979,6 @@ static void arm_smmu_page_response(struct device *dev, struct iopf_fault *unused
 	 */
 }
 
-/* Invalidation array manipulation functions */
-static inline struct arm_smmu_inv *
-arm_smmu_invs_iter_next(struct arm_smmu_invs *invs, size_t next, size_t *idx)
-{
-	while (true) {
-		if (next >= invs->num_invs) {
-			*idx = next;
-			return NULL;
-		}
-		if (!READ_ONCE(invs->inv[next].users)) {
-			next++;
-			continue;
-		}
-		*idx = next;
-		return &invs->inv[next];
-	}
-}
-
-/**
- * arm_smmu_invs_for_each_entry - Iterate over all non-trash entries in invs
- * @invs: the base invalidation array
- * @idx: a stack variable of 'size_t', to store the array index
- * @cur: a stack variable of 'struct arm_smmu_inv *'
- */
-#define arm_smmu_invs_for_each_entry(invs, idx, cur)                           \
-	for (cur = arm_smmu_invs_iter_next(invs, 0, &(idx)); cur;              \
-	     cur = arm_smmu_invs_iter_next(invs, idx + 1, &(idx)))
-
 static int arm_smmu_inv_cmp(const struct arm_smmu_inv *inv_l,
 			    const struct arm_smmu_inv *inv_r)
 {
-- 
2.43.0