[PATCH v5 16/18] iommu/arm-smmu-v3: Factor out CMDQ batch force-sync conditions

[Nicolin Chen]

arm_smmu_cmdq_batch_add_cmd_p() carries two distinct reasons for flushing
the current batch with a CMD_SYNC before appending the new command:

  - The batch's pre-assigned cmdq does not support the new command.
  - The Arm erratum 2812531 workaround (ARM_SMMU_OPT_CMDQ_FORCE_SYNC)
    forces a SYNC at one entry before the batch is full.

Factor those checks into a new arm_smmu_cmdq_batch_force_sync() helper so
that adding another force-sync condition becomes a one-line addition.

No functional change.

Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 23 +++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

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 a18a56ceeb7fb..0697bbc558d0e 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -928,16 +928,27 @@ static int arm_smmu_cmdq_batch_issue(struct arm_smmu_device *smmu,
 					   cmds->num, sync);
 }
 
+static bool arm_smmu_cmdq_batch_force_sync(struct arm_smmu_device *smmu,
+					   struct arm_smmu_cmdq_batch *cmds,
+					   struct arm_smmu_cmd *cmd)
+{
+	/* The batch's pre-assigned cmdq doesn't support the new command */
+	if (!arm_smmu_cmdq_supports_cmd(cmds->cmdq, cmd))
+		return true;
+
+	/* Arm erratum 2812531 */
+	if (cmds->num == CMDQ_BATCH_ENTRIES - 1 &&
+	    (smmu->options & ARM_SMMU_OPT_CMDQ_FORCE_SYNC))
+		return true;
+
+	return false;
+}
+
 static void arm_smmu_cmdq_batch_add_cmd_p(struct arm_smmu_device *smmu,
 					  struct arm_smmu_cmdq_batch *cmds,
 					  struct arm_smmu_cmd *cmd)
 {
-	bool force_sync = (cmds->num == CMDQ_BATCH_ENTRIES - 1) &&
-			  (smmu->options & ARM_SMMU_OPT_CMDQ_FORCE_SYNC);
-	bool unsupported_cmd;
-
-	unsupported_cmd = !arm_smmu_cmdq_supports_cmd(cmds->cmdq, cmd);
-	if (force_sync || unsupported_cmd) {
+	if (arm_smmu_cmdq_batch_force_sync(smmu, cmds, cmd)) {
 		arm_smmu_cmdq_batch_issue(smmu, cmds, true);
 		arm_smmu_cmdq_batch_init_cmd(smmu, cmds, cmd);
 	}
-- 
2.43.0