Subject: Re: [PATCH 2/9] iommu/arm-smmu-v3: Use the HW arm_smmu_cmd in cmdq selection functions

From: Pranjal Shrivastava <[email-masked]>
Date: Fri, 8 May 2026 07:47:45 +0000

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 <[email-masked]>
> ---
>  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(-)

[...]

>  	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));
>  	cmds->num++;
>  }

The memcpy is a temporary step and goes way in Patch 4.

Reviewed-by: Pranjal Shrivastava <[email-masked]>

Thanks,
Praan