Re: [PATCH V1] accel/amdxdna: Support submit commands without arguments

[Mario Limonciello <mario.limonciello@amd.com>]

On 5/7/2025 11:15 AM, Lizhi Hou wrote:
> The latest userspace runtime allows generating commands which do not
> have any argument. Remove the corresponding check in driver IOCTL to
> enable this use case.
> 
> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>

Can the userspace handle discovery of the difference?  Or does this need 
any sort of ABI discovery command introduced too?

The code change itself below looks good to me though.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>

> ---
>   drivers/accel/amdxdna/amdxdna_ctx.c | 22 ++++++++++++----------
>   1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/accel/amdxdna/amdxdna_ctx.c b/drivers/accel/amdxdna/amdxdna_ctx.c
> index 43442b9e273b..be073224bd69 100644
> --- a/drivers/accel/amdxdna/amdxdna_ctx.c
> +++ b/drivers/accel/amdxdna/amdxdna_ctx.c
> @@ -496,11 +496,11 @@ static int amdxdna_drm_submit_execbuf(struct amdxdna_client *client,
>   				      struct amdxdna_drm_exec_cmd *args)
>   {
>   	struct amdxdna_dev *xdna = client->xdna;
> -	u32 *arg_bo_hdls;
> +	u32 *arg_bo_hdls = NULL;
>   	u32 cmd_bo_hdl;
>   	int ret;
>   
> -	if (!args->arg_count || args->arg_count > MAX_ARG_COUNT) {
> +	if (args->arg_count > MAX_ARG_COUNT) {
>   		XDNA_ERR(xdna, "Invalid arg bo count %d", args->arg_count);
>   		return -EINVAL;
>   	}
> @@ -512,14 +512,16 @@ static int amdxdna_drm_submit_execbuf(struct amdxdna_client *client,
>   	}
>   
>   	cmd_bo_hdl = (u32)args->cmd_handles;
> -	arg_bo_hdls = kcalloc(args->arg_count, sizeof(u32), GFP_KERNEL);
> -	if (!arg_bo_hdls)
> -		return -ENOMEM;
> -	ret = copy_from_user(arg_bo_hdls, u64_to_user_ptr(args->args),
> -			     args->arg_count * sizeof(u32));
> -	if (ret) {
> -		ret = -EFAULT;
> -		goto free_cmd_bo_hdls;
> +	if (args->arg_count) {
> +		arg_bo_hdls = kcalloc(args->arg_count, sizeof(u32), GFP_KERNEL);
> +		if (!arg_bo_hdls)
> +			return -ENOMEM;
> +		ret = copy_from_user(arg_bo_hdls, u64_to_user_ptr(args->args),
> +				     args->arg_count * sizeof(u32));
> +		if (ret) {
> +			ret = -EFAULT;
> +			goto free_cmd_bo_hdls;
> +		}
>   	}
>   
>   	ret = amdxdna_cmd_submit(client, cmd_bo_hdl, arg_bo_hdls,