Messages in this thread Patch in this message | | | From | Zhen Lei <> | Subject | [PATCH v2 1/2] iommu/arm-smmu-v3: Properly handle the return value of arm_smmu_cmdq_build_cmd() | Date | Wed, 18 Aug 2021 16:04:51 +0800 |
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1. Build command CMD_SYNC cannot fail. So the return value can be ignored. 2. The arm_smmu_cmdq_build_cmd() almost never fails, the addition of "unlikely()" can optimize the instruction pipeline. 3. Check the return value in arm_smmu_cmdq_batch_add().
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 18 ++++++++++++------ 1 file changed, 12 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 3646bf8f021cd4c..01e95b56ffa07d1 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -409,10 +409,7 @@ static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu, dev_err(smmu->dev, "\t0x%016llx\n", (unsigned long long)cmd[i]); /* Convert the erroneous command into a CMD_SYNC */ - if (arm_smmu_cmdq_build_cmd(cmd, &cmd_sync)) { - dev_err(smmu->dev, "failed to convert to CMD_SYNC\n"); - return; - } + arm_smmu_cmdq_build_cmd(cmd, &cmd_sync); queue_write(Q_ENT(q, cons), cmd, q->ent_dwords); } @@ -860,7 +857,7 @@ static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, { u64 cmd[CMDQ_ENT_DWORDS]; - if (arm_smmu_cmdq_build_cmd(cmd, ent)) { + if (unlikely(arm_smmu_cmdq_build_cmd(cmd, ent))) { dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", ent->opcode); return -EINVAL; @@ -885,11 +882,20 @@ static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu, struct arm_smmu_cmdq_batch *cmds, struct arm_smmu_cmdq_ent *cmd) { + int index; + if (cmds->num == CMDQ_BATCH_ENTRIES) { arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, false); cmds->num = 0; } - arm_smmu_cmdq_build_cmd(&cmds->cmds[cmds->num * CMDQ_ENT_DWORDS], cmd); + + index = cmds->num * CMDQ_ENT_DWORDS; + if (unlikely(arm_smmu_cmdq_build_cmd(&cmds->cmds[index], cmd))) { + dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", + cmd->opcode); + return; + } + cmds->num++; } -- 2.26.0.106.g9fadedd
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