drm: Plumb modifiers through plane init

This is the plumbing for supporting fb modifiers on planes. Modifiers
have already been introduced to some extent, but this series will extend
this to allow querying modifiers per plane. Based on this, the client to
enable optimal modifications for framebuffers.

This patch simply allows the DRM drivers to initialize their list of
supported modifiers upon initializing the plane.

v2: A minor addition from Daniel

v3:
* Updated commit message
* s/INVALID/DRM_FORMAT_MOD_INVALID (Liviu)
* Remove some excess newlines (Liviu)
* Update comment for > 64 modifiers (Liviu)

v4: Minor comment adjustments (Liviu)

v5: Some new platforms added due to rebase

v6: Add some missed plane inits (or maybe they're new - who knows at
this point) (Daniel)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Daniel Stone <daniels@collabora.com> (v2)
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Stone <daniels@collabora.com>

1 files changed, 35 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 5dc8c4350602..d3fc561d7b48 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -70,6 +70,8 @@ static unsigned int drm_num_planes(struct drm_device *dev)
  * @funcs: callbacks for the new plane
  * @formats: array of supported formats (DRM_FORMAT\_\*)
  * @format_count: number of elements in @formats
+ * @format_modifiers: array of struct drm_format modifiers terminated by
+ *                    DRM_FORMAT_MOD_INVALID
  * @type: type of plane (overlay, primary, cursor)
  * @name: printf style format string for the plane name, or NULL for default name
  *
@@ -82,10 +84,12 @@ int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane,
 			     uint32_t possible_crtcs,
 			     const struct drm_plane_funcs *funcs,
 			     const uint32_t *formats, unsigned int format_count,
+			     const uint64_t *format_modifiers,
 			     enum drm_plane_type type,
 			     const char *name, ...)
 {
 	struct drm_mode_config *config = &dev->mode_config;
+	unsigned int format_modifier_count = 0;
 	int ret;
 
 	ret = drm_mode_object_add(dev, &plane->base, DRM_MODE_OBJECT_PLANE);
@@ -105,6 +109,31 @@ int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane,
 		return -ENOMEM;
 	}
 
+	/*
+	 * First driver to need more than 64 formats needs to fix this. Each
+	 * format is encoded as a bit and the current code only supports a u64.
+	 */
+	if (WARN_ON(format_count > 64))
+		return -EINVAL;
+
+	if (format_modifiers) {
+		const uint64_t *temp_modifiers = format_modifiers;
+		while (*temp_modifiers++ != DRM_FORMAT_MOD_INVALID)
+			format_modifier_count++;
+	}
+
+	plane->modifier_count = format_modifier_count;
+	plane->modifiers = kmalloc_array(format_modifier_count,
+					 sizeof(format_modifiers[0]),
+					 GFP_KERNEL);
+
+	if (format_modifier_count && !plane->modifiers) {
+		DRM_DEBUG_KMS("out of memory when allocating plane\n");
+		kfree(plane->format_types);
+		drm_mode_object_unregister(dev, &plane->base);
+		return -ENOMEM;
+	}
+
 	if (name) {
 		va_list ap;
 
@@ -117,12 +146,15 @@ int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane,
 	}
 	if (!plane->name) {
 		kfree(plane->format_types);
+		kfree(plane->modifiers);
 		drm_mode_object_unregister(dev, &plane->base);
 		return -ENOMEM;
 	}
 
 	memcpy(plane->format_types, formats, format_count * sizeof(uint32_t));
 	plane->format_count = format_count;
+	memcpy(plane->modifiers, format_modifiers,
+	       format_modifier_count * sizeof(format_modifiers[0]));
 	plane->possible_crtcs = possible_crtcs;
 	plane->type = type;
 
@@ -205,7 +237,8 @@ int drm_plane_init(struct drm_device *dev, struct drm_plane *plane,
 
 	type = is_primary ? DRM_PLANE_TYPE_PRIMARY : DRM_PLANE_TYPE_OVERLAY;
 	return drm_universal_plane_init(dev, plane, possible_crtcs, funcs,
-					formats, format_count, type, NULL);
+					formats, format_count,
+					NULL, type, NULL);
 }
 EXPORT_SYMBOL(drm_plane_init);
 
@@ -224,6 +257,7 @@ void drm_plane_cleanup(struct drm_plane *plane)
 	drm_modeset_lock_fini(&plane->mutex);
 
 	kfree(plane->format_types);
+	kfree(plane->modifiers);
 	drm_mode_object_unregister(dev, &plane->base);
 
 	BUG_ON(list_empty(&plane->head));