drm/v3d: add generic ioctl extension

Add support to attach generic extensions on job submission. This patch
is third prep work to enable multiple syncobjs on job submission. With
this work, when the job submission interface needs to be extended to
accommodate a new feature, we will use a generic extension struct where
an id determines the data type to be pointed. The first application is
to enable multiples in/out syncobj (next patch), but the base is
already done for future features. Therefore, to attach a new feature,
a specific extension struct should subclass drm_v3d_extension and
update the list of extensions in a job submission.

v2:
- remove redundant elements to subclass struct (Daniel)

v3:
- add comment for v3d_get_extensions

Signed-off-by: Melissa Wen <mwen@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ed53b1cd7e3125b76f18fe3fb995a04393639bc6.1633016479.git.mwen@igalia.com

1 files changed, 71 insertions, 3 deletions

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
index f932e73fb5c6..93f130fb3a13 100644
--- a/drivers/gpu/drm/v3d/v3d_gem.c
+++ b/drivers/gpu/drm/v3d/v3d_gem.c
@@ -537,6 +537,36 @@ v3d_attach_fences_and_unlock_reservation(struct drm_file *file_priv,
 	}
 }
 
+/* Whenever userspace sets ioctl extensions, v3d_get_extensions parses data
+ * according to the extension id (name).
+ */
+static int
+v3d_get_extensions(struct drm_file *file_priv, u64 ext_handles)
+{
+	struct drm_v3d_extension __user *user_ext;
+
+	user_ext = u64_to_user_ptr(ext_handles);
+	while (user_ext) {
+		struct drm_v3d_extension ext;
+
+		if (copy_from_user(&ext, user_ext, sizeof(ext))) {
+			DRM_DEBUG("Failed to copy submit extension\n");
+			return -EFAULT;
+		}
+
+		switch (ext.id) {
+		case 0:
+		default:
+			DRM_DEBUG_DRIVER("Unknown extension id: %d\n", ext.id);
+			return -EINVAL;
+		}
+
+		user_ext = u64_to_user_ptr(ext.next);
+	}
+
+	return 0;
+}
+
 /**
  * v3d_submit_cl_ioctl() - Submits a job (frame) to the V3D.
  * @dev: DRM device
@@ -565,15 +595,24 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 
 	trace_v3d_submit_cl_ioctl(&v3d->drm, args->rcl_start, args->rcl_end);
 
-	if (args->pad != 0)
+	if (args->pad)
 		return -EINVAL;
 
-	if (args->flags != 0 &&
-	    args->flags != DRM_V3D_SUBMIT_CL_FLUSH_CACHE) {
+	if (args->flags &&
+	    args->flags & ~(DRM_V3D_SUBMIT_CL_FLUSH_CACHE |
+			    DRM_V3D_SUBMIT_EXTENSION)) {
 		DRM_INFO("invalid flags: %d\n", args->flags);
 		return -EINVAL;
 	}
 
+	if (args->flags & DRM_V3D_SUBMIT_EXTENSION) {
+		ret = v3d_get_extensions(file_priv, args->extensions);
+		if (ret) {
+			DRM_DEBUG("Failed to get extensions.\n");
+			return ret;
+		}
+	}
+
 	ret = v3d_job_init(v3d, file_priv, (void *)&render, sizeof(*render),
 			   v3d_render_job_free, args->in_sync_rcl, V3D_RENDER);
 	if (ret)
@@ -702,6 +741,19 @@ v3d_submit_tfu_ioctl(struct drm_device *dev, void *data,
 
 	trace_v3d_submit_tfu_ioctl(&v3d->drm, args->iia);
 
+	if (args->flags && !(args->flags & DRM_V3D_SUBMIT_EXTENSION)) {
+		DRM_DEBUG("invalid flags: %d\n", args->flags);
+		return -EINVAL;
+	}
+
+	if (args->flags & DRM_V3D_SUBMIT_EXTENSION) {
+		ret = v3d_get_extensions(file_priv, args->extensions);
+		if (ret) {
+			DRM_DEBUG("Failed to get extensions.\n");
+			return ret;
+		}
+	}
+
 	ret = v3d_job_init(v3d, file_priv, (void *)&job, sizeof(*job),
 			   v3d_job_free, args->in_sync, V3D_TFU);
 	if (ret)
@@ -786,11 +838,27 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data,
 
 	trace_v3d_submit_csd_ioctl(&v3d->drm, args->cfg[5], args->cfg[6]);
 
+	if (args->pad)
+		return -EINVAL;
+
 	if (!v3d_has_csd(v3d)) {
 		DRM_DEBUG("Attempting CSD submit on non-CSD hardware\n");
 		return -EINVAL;
 	}
 
+	if (args->flags && !(args->flags & DRM_V3D_SUBMIT_EXTENSION)) {
+		DRM_INFO("invalid flags: %d\n", args->flags);
+		return -EINVAL;
+	}
+
+	if (args->flags & DRM_V3D_SUBMIT_EXTENSION) {
+		ret = v3d_get_extensions(file_priv, args->extensions);
+		if (ret) {
+			DRM_DEBUG("Failed to get extensions.\n");
+			return ret;
+		}
+	}
+
 	ret = v3d_job_init(v3d, file_priv, (void *)&job, sizeof(*job),
 			   v3d_job_free, args->in_sync, V3D_CSD);
 	if (ret)