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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 <[email protected]>
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drivers/iommu/arm-smmu-v3.c

Lines changed: 13 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -418,8 +418,7 @@
418418

419419
/* High-level queue structures */
420420
#define ARM_SMMU_POLL_TIMEOUT_US 100
421-
#define ARM_SMMU_CMDQ_DRAIN_TIMEOUT_US 1000000 /* 1s! */
422-
#define ARM_SMMU_SYNC_TIMEOUT_US 1000000 /* 1s! */
421+
#define ARM_SMMU_CMDQ_SYNC_TIMEOUT_US 1000000 /* 1s! */
423422

424423
#define MSI_IOVA_BASE 0x8000000
425424
#define MSI_IOVA_LENGTH 0x100000
@@ -767,17 +766,17 @@ static void queue_inc_prod(struct arm_smmu_queue *q)
767766
* Wait for the SMMU to consume items. If drain is true, wait until the queue
768767
* is empty. Otherwise, wait until there is at least one free slot.
769768
*/
770-
static int queue_poll_cons(struct arm_smmu_queue *q, bool drain, bool wfe)
769+
static int queue_poll_cons(struct arm_smmu_queue *q, bool sync, bool wfe)
771770
{
772771
ktime_t timeout;
773772
unsigned int delay = 1;
774773

775-
/* Wait longer if it's queue drain */
776-
timeout = ktime_add_us(ktime_get(), drain ?
777-
ARM_SMMU_CMDQ_DRAIN_TIMEOUT_US :
774+
/* Wait longer if it's a CMD_SYNC */
775+
timeout = ktime_add_us(ktime_get(), sync ?
776+
ARM_SMMU_CMDQ_SYNC_TIMEOUT_US :
778777
ARM_SMMU_POLL_TIMEOUT_US);
779778

780-
while (queue_sync_cons(q), (drain ? !queue_empty(q) : queue_full(q))) {
779+
while (queue_sync_cons(q), (sync ? !queue_empty(q) : queue_full(q))) {
781780
if (ktime_compare(ktime_get(), timeout) > 0)
782781
return -ETIMEDOUT;
783782

@@ -986,10 +985,13 @@ static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
986985
*/
987986
static int __arm_smmu_sync_poll_msi(struct arm_smmu_device *smmu, u32 sync_idx)
988987
{
989-
ktime_t timeout = ktime_add_us(ktime_get(), ARM_SMMU_SYNC_TIMEOUT_US);
990-
u32 val = smp_cond_load_acquire(&smmu->sync_count,
991-
(int)(VAL - sync_idx) >= 0 ||
992-
!ktime_before(ktime_get(), timeout));
988+
ktime_t timeout;
989+
u32 val;
990+
991+
timeout = ktime_add_us(ktime_get(), ARM_SMMU_CMDQ_SYNC_TIMEOUT_US);
992+
val = smp_cond_load_acquire(&smmu->sync_count,
993+
(int)(VAL - sync_idx) >= 0 ||
994+
!ktime_before(ktime_get(), timeout));
993995

994996
return (int)(val - sync_idx) < 0 ? -ETIMEDOUT : 0;
995997
}

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