[v9,07/11] drm: Handle aspect-ratio info in getblob

Commit Message

Nautiyal, Ankit K March 22, 2018, 8:18 a.m. UTC

From: Ankit Nautiyal <[e-mail]>

If the user-space does not support aspect-ratio, then getblob called
with the blob id of a user-mode, should clear the aspect-ratio
information in the blob data.

Currently for a given blob id, there is no way to determine if the
blob stores user-mode or not. This can only be ascertained when the
blob is used for an atomic modeset call.

This patch:
-adds a new field 'is_video_mode' in drm_property_blob to
 differentiate between the video mode blobs and the other blobs.
-sets the field 'is_video_mode' when the blob is used for modeset.
-removes the aspect-ratio info from the user-mode data if aspect-ratio
 is not supported by the user, while returning the blob to the user,
 in getblob ioctl.

Signed-off-by: Ankit Nautiyal <[e-mail]>

V5: This patch is introduced in the rev-5 of the series.
V6: As suggested by Ville:
    -added helper functions for determining if aspect-ratio is
     expected in user-mode and for allowing/disallowing the
     aspect-ratio, if its not expected.
    -avoided clobbering of blob-data, instead cleared the aspect-ratio
     in the user-mode only, so that another client with aspect-ratio
     cap, can still get the aspect-ratio information from getblob.
V7: Fixed warning [Wint-to-pointer-cast] for 32 bit platforms.
V8: Changed the parameter of aspect-ratio helper functions from 32 bit
    flags to user-mode, to avoid passing random integers, as suggested
    by Ville.
V9: Handled the case when blob is null for a given blob-id.
---
 drivers/gpu/drm/drm_atomic.c   |  5 +++++
 drivers/gpu/drm/drm_modes.c    | 47 ++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_property.c | 21 ++++++++++++++++++-
 include/drm/drm_modes.h        |  4 ++++
 include/drm/drm_property.h     |  2 ++
 5 files changed, 78 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 7d25c42..18dc384 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -494,6 +494,11 @@  int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 	else if (property == config->prop_mode_id) {
 		struct drm_property_blob *mode =
 			drm_property_lookup_blob(dev, val);
+		if (mode)
+			mode->is_video_mode = true;
+		else
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] Blob not found.\n",
+					 crtc->base.id, crtc->name);
 		ret = drm_atomic_set_mode_prop_for_crtc(state, mode);
 		drm_property_blob_put(mode);
 		return ret;
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index df459cb..8d51790 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1753,3 +1753,50 @@  bool drm_mode_is_420(const struct drm_display_info *display,
 		drm_mode_is_420_also(display, mode);
 }
 EXPORT_SYMBOL(drm_mode_is_420);
+
+/**
+ * drm_mode_aspect_ratio_allowed - checks if the aspect-ratio information
+ * is expected from the user-mode.
+ *
+ * If the user has set aspect-ratio cap, then the flag of the user-mode is
+ * allowed to contain aspect-ratio value.
+ * If the user does not set aspect-ratio cap, then the only value allowed in the
+ * flags bits is aspect-ratio NONE.
+ *
+ * @file_priv: file private structure to get the user capabilities
+ * @umode: drm_mode_modeinfo struct, whose flag carry the aspect ratio
+ * information.
+ *
+ * Returns:
+ * true if the aspect-ratio info is allowed in the user-mode flags.
+ * false, otherwise.
+ */
+bool
+drm_mode_aspect_ratio_allowed(const struct drm_file *file_priv,
+			      struct drm_mode_modeinfo *umode)
+{
+	return file_priv->aspect_ratio_allowed || (umode->flags &
+		DRM_MODE_FLAG_PIC_AR_MASK) == DRM_MODE_FLAG_PIC_AR_NONE;
+}
+EXPORT_SYMBOL(drm_mode_aspect_ratio_allowed);
+
+/**
+ * drm_mode_filter_aspect_ratio_flags - filters the aspect-ratio bits in the
+ * user-mode flags.
+ *
+ * Checks if the aspect-ratio information is allowed. Resets the aspect-ratio
+ * bits in the user-mode flags, if aspect-ratio info is not allowed.
+ *
+ * @file_priv: file private structure to get the user capabilities.
+ * @umode: drm_mode_modeinfo struct, whose flags' aspect-ratio bits needs to
+ * be filtered.
+ *
+ */
+void
+drm_mode_filter_aspect_ratio_flags(const struct drm_file *file_priv,
+				   struct drm_mode_modeinfo *umode)
+{
+	if (!drm_mode_aspect_ratio_allowed(file_priv, umode))
+		umode->flags &= ~DRM_MODE_FLAG_PIC_AR_MASK;
+}
+EXPORT_SYMBOL(drm_mode_filter_aspect_ratio_flags);
diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c
index 8f4672d..c031af9 100644
--- a/drivers/gpu/drm/drm_property.c
+++ b/drivers/gpu/drm/drm_property.c
@@ -765,7 +765,26 @@  int drm_mode_getblob_ioctl(struct drm_device *dev,
 		return -ENOENT;
 
 	if (out_resp->length == blob->length) {
-		if (copy_to_user(u64_to_user_ptr(out_resp->data),
+		if (blob->is_video_mode) {
+			struct drm_property_blob *temp_blob;
+			struct drm_mode_modeinfo *mode;
+
+			temp_blob = drm_property_create_blob(dev,
+							     out_resp->length,
+							     blob->data);
+			mode = (struct drm_mode_modeinfo *) temp_blob->data;
+			drm_mode_filter_aspect_ratio_flags(file_priv, mode);
+			if (copy_to_user(u64_to_user_ptr(out_resp->data),
+					 temp_blob->data,
+					 temp_blob->length)) {
+				drm_property_blob_put(temp_blob);
+				ret = -EFAULT;
+				goto unref;
+			}
+			drm_property_blob_put(temp_blob);
+		}
+
+		else if (copy_to_user(u64_to_user_ptr(out_resp->data),
 				 blob->data,
 				 blob->length)) {
 			ret = -EFAULT;
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 2f78b7e..e0b060d 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -461,6 +461,10 @@  bool drm_mode_is_420_also(const struct drm_display_info *display,
 			  const struct drm_display_mode *mode);
 bool drm_mode_is_420(const struct drm_display_info *display,
 		     const struct drm_display_mode *mode);
+bool drm_mode_aspect_ratio_allowed(const struct drm_file *file_priv,
+				   struct drm_mode_modeinfo *umode);
+void drm_mode_filter_aspect_ratio_flags(const struct drm_file *file_priv,
+					struct drm_mode_modeinfo *umode);
 
 struct drm_display_mode *drm_cvt_mode(struct drm_device *dev,
 				      int hdisplay, int vdisplay, int vrefresh,
diff --git a/include/drm/drm_property.h b/include/drm/drm_property.h
index d1423c7f..fc18d53 100644
--- a/include/drm/drm_property.h
+++ b/include/drm/drm_property.h
@@ -194,6 +194,7 @@  struct drm_property {
  * @head_global: entry on the global blob list in
  * 	&drm_mode_config.property_blob_list.
  * @head_file: entry on the per-file blob list in &drm_file.blobs list.
+ * @is_video_mode: flag to mark the blobs that contain drm_mode_modeinfo.
  * @length: size of the blob in bytes, invariant over the lifetime of the object
  * @data: actual data, embedded at the end of this structure
  *
@@ -208,6 +209,7 @@  struct drm_property_blob {
 	struct drm_device *dev;
 	struct list_head head_global;
 	struct list_head head_file;
+	bool is_video_mode;
 	size_t length;
 	void *data;
 };