iommu/arm-smmu-v3: Consolidate identical timeouts

We have separate (identical) timeout values for polling for a queue to
drain and waiting for an MSI to signal CMD_SYNC completion. In reality,
we only wait for the command queue to drain if we're waiting on a sync,
so just merged these two timeouts into a single constant.

Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 3876a032858938f4c59850022ea637855bf30d4b..c148f76dd8e282f1adf4a274fa70043894f1eb60 100644 (file)
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -418,8 +418,7 @@
 
 /* High-level queue structures */
 #define ARM_SMMU_POLL_TIMEOUT_US       100
-#define ARM_SMMU_CMDQ_DRAIN_TIMEOUT_US 1000000 /* 1s! */
-#define ARM_SMMU_SYNC_TIMEOUT_US       1000000 /* 1s! */
+#define ARM_SMMU_CMDQ_SYNC_TIMEOUT_US  1000000 /* 1s! */
 
 #define MSI_IOVA_BASE                  0x8000000
 #define MSI_IOVA_LENGTH                        0x100000
@@ -767,17 +766,17 @@ static void queue_inc_prod(struct arm_smmu_queue *q)
  * Wait for the SMMU to consume items. If drain is true, wait until the queue
  * is empty. Otherwise, wait until there is at least one free slot.
  */
-static int queue_poll_cons(struct arm_smmu_queue *q, bool drain, bool wfe)
+static int queue_poll_cons(struct arm_smmu_queue *q, bool sync, bool wfe)
 {
        ktime_t timeout;
        unsigned int delay = 1;
 
-       /* Wait longer if it's queue drain */
-       timeout = ktime_add_us(ktime_get(), drain ?
-                                           ARM_SMMU_CMDQ_DRAIN_TIMEOUT_US :
+       /* Wait longer if it's a CMD_SYNC */
+       timeout = ktime_add_us(ktime_get(), sync ?
+                                           ARM_SMMU_CMDQ_SYNC_TIMEOUT_US :
                                            ARM_SMMU_POLL_TIMEOUT_US);
 
-       while (queue_sync_cons(q), (drain ? !queue_empty(q) : queue_full(q))) {
+       while (queue_sync_cons(q), (sync ? !queue_empty(q) : queue_full(q))) {
                if (ktime_compare(ktime_get(), timeout) > 0)
                        return -ETIMEDOUT;
 
@@ -986,10 +985,13 @@ static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
  */
 static int __arm_smmu_sync_poll_msi(struct arm_smmu_device *smmu, u32 sync_idx)
 {
-       ktime_t timeout = ktime_add_us(ktime_get(), ARM_SMMU_SYNC_TIMEOUT_US);
-       u32 val = smp_cond_load_acquire(&smmu->sync_count,
-                                       (int)(VAL - sync_idx) >= 0 ||
-                                       !ktime_before(ktime_get(), timeout));
+       ktime_t timeout;
+       u32 val;
+
+       timeout = ktime_add_us(ktime_get(), ARM_SMMU_CMDQ_SYNC_TIMEOUT_US);
+       val = smp_cond_load_acquire(&smmu->sync_count,
+                                   (int)(VAL - sync_idx) >= 0 ||
+                                   !ktime_before(ktime_get(), timeout));
 
        return (int)(val - sync_idx) < 0 ? -ETIMEDOUT : 0;
 }