accel/amdxdna: Support submit commands without arguments

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.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://lore.kernel.org/r/20250507161500.2339701-1-lizhi.hou@amd.com
Link: https://lore.kernel.org/r/20250507161500.2339701-1-lizhi.hou@amd.com

Author: houlz0507

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,