diff options
Diffstat (limited to 'drivers/iommu/arm-smmu-v3.c')
| -rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index fc6eb752ab35..eb9937225d64 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -683,7 +683,13 @@ static void queue_inc_cons(struct arm_smmu_queue *q) u32 cons = (Q_WRP(q, q->cons) | Q_IDX(q, q->cons)) + 1; q->cons = Q_OVF(q, q->cons) | Q_WRP(q, cons) | Q_IDX(q, cons); - writel(q->cons, q->cons_reg); + + /* + * Ensure that all CPU accesses (reads and writes) to the queue + * are complete before we update the cons pointer. + */ + mb(); + writel_relaxed(q->cons, q->cons_reg); } static int queue_sync_prod(struct arm_smmu_queue *q) |