[PATCH 2/9] iommu/arm-smmu-v3: Use the HW arm_smmu_cmd in cmdq selection functions
Mostafa Saleh
smostafa at google.com
Thu May 7 02:21:28 PDT 2026
On Fri, May 01, 2026 at 11:29:11AM -0300, Jason Gunthorpe wrote:
> Start removing the use of struct arm_smmu_cmdq_ent, starting at the
> lower levels of the call chain. Change the functions that determine what
> cmdq to issue the batch to into using struct arm_smmu_cmd directly.
>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 47 ++++++++++++-------
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 8 ++--
> .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 8 ++--
> 3 files changed, 38 insertions(+), 25 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 e8d7dbe495f030..5cdeaec890592f 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -371,12 +371,12 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
> }
>
> static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu,
> - struct arm_smmu_cmdq_ent *ent)
> + struct arm_smmu_cmd *cmd)
> {
> struct arm_smmu_cmdq *cmdq = NULL;
>
> if (smmu->impl_ops && smmu->impl_ops->get_secondary_cmdq)
> - cmdq = smmu->impl_ops->get_secondary_cmdq(smmu, ent);
> + cmdq = smmu->impl_ops->get_secondary_cmdq(smmu, cmd);
>
> return cmdq ?: &smmu->cmdq;
> }
> @@ -924,16 +924,16 @@ static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
> struct arm_smmu_cmdq_ent *ent,
> bool sync)
> {
> - u64 cmd[CMDQ_ENT_DWORDS];
> + struct arm_smmu_cmd cmd;
>
> - if (unlikely(arm_smmu_cmdq_build_cmd(cmd, ent))) {
> + if (unlikely(arm_smmu_cmdq_build_cmd(cmd.data, ent))) {
> dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n",
> ent->opcode);
> return -EINVAL;
> }
>
> return arm_smmu_cmdq_issue_cmdlist(
> - smmu, arm_smmu_get_cmdq(smmu, ent), cmd, 1, sync);
> + smmu, arm_smmu_get_cmdq(smmu, &cmd), cmd.data, 1, sync);
> }
>
> static int arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
> @@ -948,42 +948,55 @@ static int arm_smmu_cmdq_issue_cmd_with_sync(struct arm_smmu_device *smmu,
> return __arm_smmu_cmdq_issue_cmd(smmu, ent, true);
> }
>
> +static void arm_smmu_cmdq_batch_init_cmd(struct arm_smmu_device *smmu,
> + struct arm_smmu_cmdq_batch *cmds,
> + struct arm_smmu_cmd *cmd)
> +{
> + cmds->num = 0;
> + cmds->cmdq = arm_smmu_get_cmdq(smmu, cmd);
> +}
> +
> static void arm_smmu_cmdq_batch_init(struct arm_smmu_device *smmu,
> struct arm_smmu_cmdq_batch *cmds,
> struct arm_smmu_cmdq_ent *ent)
> {
> - cmds->num = 0;
> - cmds->cmdq = arm_smmu_get_cmdq(smmu, ent);
> + struct arm_smmu_cmd cmd;
> +
> + arm_smmu_cmdq_build_cmd(cmd.data, ent);
> + arm_smmu_cmdq_batch_init_cmd(smmu, cmds, &cmd);
> }
>
> static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
> struct arm_smmu_cmdq_batch *cmds,
> - struct arm_smmu_cmdq_ent *cmd)
> + struct arm_smmu_cmdq_ent *ent)
> {
> - bool unsupported_cmd = !arm_smmu_cmdq_supports_cmd(cmds->cmdq, cmd);
> bool force_sync = (cmds->num == CMDQ_BATCH_ENTRIES - 1) &&
> (smmu->options & ARM_SMMU_OPT_CMDQ_FORCE_SYNC);
> + struct arm_smmu_cmd cmd;
> + bool unsupported_cmd;
> int index;
>
> + if (unlikely(arm_smmu_cmdq_build_cmd(cmd.data, ent))) {
> + dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n",
> + ent->opcode);
> + return;
> + }
> +
> + unsupported_cmd = !arm_smmu_cmdq_supports_cmd(cmds->cmdq, &cmd);
> if (force_sync || unsupported_cmd) {
> arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
> cmds->num, true);
> - arm_smmu_cmdq_batch_init(smmu, cmds, cmd);
> + arm_smmu_cmdq_batch_init_cmd(smmu, cmds, &cmd);
> }
>
> if (cmds->num == CMDQ_BATCH_ENTRIES) {
> arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
> cmds->num, false);
> - arm_smmu_cmdq_batch_init(smmu, cmds, cmd);
> + arm_smmu_cmdq_batch_init_cmd(smmu, cmds, &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;
> - }
> -
> + memcpy(&cmds->cmds[index], cmd.data, sizeof(cmd.data));
Maybe this would be better squashed with other arm_smmu_cmdq_batch
patch to avoid this memcpy, but no strong opinion.
Reviewed-by: Mostafa Saleh <smostafa at google.com>
Thanks,
Mostafa
> cmds->num++;
> }
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index 092179f689e9f1..6d73f6b63e64a9 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -641,13 +641,13 @@ struct arm_smmu_cmdq {
> atomic_long_t *valid_map;
> atomic_t owner_prod;
> atomic_t lock;
> - bool (*supports_cmd)(struct arm_smmu_cmdq_ent *ent);
> + bool (*supports_cmd)(struct arm_smmu_cmd *cmd);
> };
>
> static inline bool arm_smmu_cmdq_supports_cmd(struct arm_smmu_cmdq *cmdq,
> - struct arm_smmu_cmdq_ent *ent)
> + struct arm_smmu_cmd *cmd)
> {
> - return cmdq->supports_cmd ? cmdq->supports_cmd(ent) : true;
> + return cmdq->supports_cmd ? cmdq->supports_cmd(cmd) : true;
> }
>
> struct arm_smmu_cmdq_batch {
> @@ -815,7 +815,7 @@ struct arm_smmu_impl_ops {
> void (*device_remove)(struct arm_smmu_device *smmu);
> int (*init_structures)(struct arm_smmu_device *smmu);
> struct arm_smmu_cmdq *(*get_secondary_cmdq)(
> - struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent);
> + struct arm_smmu_device *smmu, struct arm_smmu_cmd *cmd);
> /*
> * An implementation should define its own type other than the default
> * IOMMU_HW_INFO_TYPE_ARM_SMMUV3. And it must validate the input @type
> diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
> index 83f6e9f6c51d6b..b4d8c1f2fd3878 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
> @@ -367,9 +367,9 @@ static irqreturn_t tegra241_cmdqv_isr(int irq, void *devid)
>
> /* Command Queue Function */
>
> -static bool tegra241_guest_vcmdq_supports_cmd(struct arm_smmu_cmdq_ent *ent)
> +static bool tegra241_guest_vcmdq_supports_cmd(struct arm_smmu_cmd *cmd)
> {
> - switch (ent->opcode) {
> + switch (FIELD_GET(CMDQ_0_OP, cmd->data[0])) {
> case CMDQ_OP_TLBI_NH_ASID:
> case CMDQ_OP_TLBI_NH_VA:
> case CMDQ_OP_ATC_INV:
> @@ -381,7 +381,7 @@ static bool tegra241_guest_vcmdq_supports_cmd(struct arm_smmu_cmdq_ent *ent)
>
> static struct arm_smmu_cmdq *
> tegra241_cmdqv_get_cmdq(struct arm_smmu_device *smmu,
> - struct arm_smmu_cmdq_ent *ent)
> + struct arm_smmu_cmd *cmd)
> {
> struct tegra241_cmdqv *cmdqv =
> container_of(smmu, struct tegra241_cmdqv, smmu);
> @@ -409,7 +409,7 @@ tegra241_cmdqv_get_cmdq(struct arm_smmu_device *smmu,
> return NULL;
>
> /* Unsupported CMD goes for smmu->cmdq pathway */
> - if (!arm_smmu_cmdq_supports_cmd(&vcmdq->cmdq, ent))
> + if (!arm_smmu_cmdq_supports_cmd(&vcmdq->cmdq, cmd))
> return NULL;
> return &vcmdq->cmdq;
> }
> --
> 2.43.0
>
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