7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fangyu Yu [ Upstream commit 4c50bec3d54288230aafb7fe3d2930d42beb14fd ] Do not wait for IOFENCE.C completion when the command failed to enter the queue. The command was not published to hardware, so waiting for its producer index can only report a misleading execution timeout. Fixes: 856c0cfe5c5f ("iommu/riscv: Command and fault queue support") Signed-off-by: Fangyu Yu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/riscv/iommu.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c index e335beb70e422..fe8e6d0f8a23b 100644 --- a/drivers/iommu/riscv/iommu.c +++ b/drivers/iommu/riscv/iommu.c @@ -419,8 +419,9 @@ static int riscv_iommu_queue_wait_for_space(struct riscv_iommu_queue *queue, } /* Enqueue an entry and publish it to the hardware queue. */ -static unsigned int riscv_iommu_queue_send(struct riscv_iommu_queue *queue, - void *entry, size_t entry_size) +static int riscv_iommu_queue_send(struct riscv_iommu_queue *queue, + void *entry, size_t entry_size, + unsigned int *out_prod) { unsigned int prod; unsigned int head; @@ -462,14 +463,16 @@ static unsigned int riscv_iommu_queue_send(struct riscv_iommu_queue *queue, atomic_set(&queue->tail, prod + 1); atomic_set(&queue->prod, prod + 1); - raw_spin_unlock_irqrestore(&queue->lock, flags); + if (out_prod) + *out_prod = prod; - return prod; + raw_spin_unlock_irqrestore(&queue->lock, flags); + return 0; err_busy: /* Report the failure and continue; full RAS recovery is not implemented. */ dev_err_once(queue->iommu->dev, "Hardware error: command enqueue failed\n"); - return prod; + return ret; } /* @@ -508,7 +511,7 @@ static irqreturn_t riscv_iommu_cmdq_process(int irq, void *data) static void riscv_iommu_cmd_send(struct riscv_iommu_device *iommu, struct riscv_iommu_command *cmd) { - riscv_iommu_queue_send(&iommu->cmdq, cmd, sizeof(*cmd)); + riscv_iommu_queue_send(&iommu->cmdq, cmd, sizeof(*cmd), NULL); } /* Send IOFENCE.C command and wait for all scheduled commands to complete. */ @@ -517,9 +520,12 @@ static void riscv_iommu_cmd_sync(struct riscv_iommu_device *iommu, { struct riscv_iommu_command cmd; unsigned int prod; + int ret; riscv_iommu_cmd_iofence(&cmd); - prod = riscv_iommu_queue_send(&iommu->cmdq, &cmd, sizeof(cmd)); + ret = riscv_iommu_queue_send(&iommu->cmdq, &cmd, sizeof(cmd), &prod); + if (ret) + return; if (!timeout_us) return; -- 2.53.0