drm/colorop: Introduce new drm_colorop mode object

This patches introduces a new drm_colorop mode object. This
object represents color transformations and can be used to
define color pipelines.

We also introduce the drm_colorop_state here, as well as
various helpers and state tracking bits.

Reviewed-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Reviewed-by: Sebastian Wick <sebastian.wick@redhat.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patch.msgid.link/20251115000237.3561250-5-alex.hung@amd.com

include/drm/drm_atomic.h

@@ -30,6 +30,7 @@
 
 #include <drm/drm_crtc.h>
 #include <drm/drm_util.h>
+#include <drm/drm_colorop.h>
 
 /**
  * struct drm_crtc_commit - track modeset commits on a CRTC
@@ -157,6 +158,11 @@ struct drm_crtc_commit {
 	bool abort_completion;
 };
 
+struct __drm_colorops_state {
+	struct drm_colorop *ptr;
+	struct drm_colorop_state *state, *old_state, *new_state;
+};
+
 struct __drm_planes_state {
 	struct drm_plane *ptr;
 
@@ -531,6 +537,14 @@ struct drm_atomic_state {
 	 */
 	bool checked : 1;
 
+	/**
+	 * @colorops:
+	 *
+	 * Pointer to array of @drm_colorop and @drm_colorop_state part of this
+	 * update.
+	 */
+	struct __drm_colorops_state *colorops;
+
 	/**
 	 * @planes:
 	 *
@@ -672,6 +686,9 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state,
 struct drm_plane_state * __must_check
 drm_atomic_get_plane_state(struct drm_atomic_state *state,
 			   struct drm_plane *plane);
+struct drm_colorop_state *
+drm_atomic_get_colorop_state(struct drm_atomic_state *state,
+			     struct drm_colorop *colorop);
 struct drm_connector_state * __must_check
 drm_atomic_get_connector_state(struct drm_atomic_state *state,
 			       struct drm_connector *connector);
@@ -768,6 +785,36 @@ drm_atomic_get_new_plane_state(const struct drm_atomic_state *state,
 	return state->planes[drm_plane_index(plane)].new_state;
 }
 
+/**
+ * drm_atomic_get_old_colorop_state - get colorop state, if it exists
+ * @state: global atomic state object
+ * @colorop: colorop to grab
+ *
+ * This function returns the old colorop state for the given colorop, or
+ * NULL if the colorop is not part of the global atomic state.
+ */
+static inline struct drm_colorop_state *
+drm_atomic_get_old_colorop_state(struct drm_atomic_state *state,
+				 struct drm_colorop *colorop)
+{
+	return state->colorops[drm_colorop_index(colorop)].old_state;
+}
+
+/**
+ * drm_atomic_get_new_colorop_state - get colorop state, if it exists
+ * @state: global atomic state object
+ * @colorop: colorop to grab
+ *
+ * This function returns the new colorop state for the given colorop, or
+ * NULL if the colorop is not part of the global atomic state.
+ */
+static inline struct drm_colorop_state *
+drm_atomic_get_new_colorop_state(struct drm_atomic_state *state,
+				 struct drm_colorop *colorop)
+{
+	return state->colorops[drm_colorop_index(colorop)].new_state;
+}
+
 /**
  * drm_atomic_get_old_connector_state - get connector state, if it exists
  * @state: global atomic state object
@@ -998,6 +1045,29 @@ void drm_state_dump(struct drm_device *dev, struct drm_printer *p);
 			     (new_crtc_state) = (__state)->crtcs[__i].new_state, \
 			     (void)(new_crtc_state) /* Only to avoid unused-but-set-variable warning */, 1))
 
+/**
+ * for_each_oldnew_colorop_in_state - iterate over all colorops in an atomic update
+ * @__state: &struct drm_atomic_state pointer
+ * @colorop: &struct drm_colorop iteration cursor
+ * @old_colorop_state: &struct drm_colorop_state iteration cursor for the old state
+ * @new_colorop_state: &struct drm_colorop_state iteration cursor for the new state
+ * @__i: int iteration cursor, for macro-internal use
+ *
+ * This iterates over all colorops in an atomic update, tracking both old and
+ * new state. This is useful in places where the state delta needs to be
+ * considered, for example in atomic check functions.
+ */
+#define for_each_oldnew_colorop_in_state(__state, colorop, old_colorop_state,	\
+					 new_colorop_state, __i)		\
+	for ((__i) = 0;								\
+	     (__i) < (__state)->dev->mode_config.num_colorop;			\
+	     (__i)++)								\
+		for_each_if ((__state)->colorops[__i].ptr &&			\
+			     ((colorop) = (__state)->colorops[__i].ptr,		\
+			      (void)(colorop) /* Only to avoid unused-but-set-variable warning */, \
+			      (old_colorop_state) = (__state)->colorops[__i].old_state,\
+			      (new_colorop_state) = (__state)->colorops[__i].new_state, 1))
+
 /**
  * for_each_oldnew_plane_in_state - iterate over all planes in an atomic update
  * @__state: &struct drm_atomic_state pointer

include/drm/drm_atomic_uapi.h

@@ -37,6 +37,7 @@ struct drm_crtc;
 struct drm_connector_state;
 struct dma_fence;
 struct drm_framebuffer;
+struct drm_colorop;
 
 int __must_check
 drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,

include/drm/drm_colorop.h

@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2023 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#ifndef __DRM_COLOROP_H__
+#define __DRM_COLOROP_H__
+
+#include <drm/drm_mode_object.h>
+#include <drm/drm_mode.h>
+#include <drm/drm_property.h>
+
+/**
+ * struct drm_colorop_state - mutable colorop state
+ */
+struct drm_colorop_state {
+	/** @colorop: backpointer to the colorop */
+	struct drm_colorop *colorop;
+
+	/*
+	 * Color properties
+	 *
+	 * The following fields are not always valid, their usage depends
+	 * on the colorop type. See their associated comment for more
+	 * information.
+	 */
+
+	/** @state: backpointer to global drm_atomic_state */
+	struct drm_atomic_state *state;
+};
+
+/**
+ * struct drm_colorop - DRM color operation control structure
+ *
+ * A colorop represents one color operation. They can be chained via
+ * the 'next' pointer to build a color pipeline.
+ *
+ * Since colorops cannot stand-alone and are used to describe colorop
+ * operations on a plane they don't have their own locking mechanism but
+ * are locked and programmed along with their associated &drm_plane.
+ *
+ */
+struct drm_colorop {
+	/** @dev: parent DRM device */
+	struct drm_device *dev;
+
+	/**
+	 * @head:
+	 *
+	 * List of all colorops on @dev, linked from &drm_mode_config.colorop_list.
+	 * Invariant over the lifetime of @dev and therefore does not need
+	 * locking.
+	 */
+	struct list_head head;
+
+	/**
+	 * @index: Position inside the mode_config.list, can be used as an array
+	 * index. It is invariant over the lifetime of the colorop.
+	 */
+	unsigned int index;
+
+	/** @base: base mode object */
+	struct drm_mode_object base;
+
+	/**
+	 * @plane:
+	 *
+	 * The plane on which the colorop sits. A drm_colorop is always unique
+	 * to a plane.
+	 */
+	struct drm_plane *plane;
+
+	/**
+	 * @state:
+	 *
+	 * Current atomic state for this colorop.
+	 *
+	 * This is protected by @mutex. Note that nonblocking atomic commits
+	 * access the current colorop state without taking locks.
+	 */
+	struct drm_colorop_state *state;
+
+	/*
+	 * Color properties
+	 *
+	 * The following fields are not always valid, their usage depends
+	 * on the colorop type. See their associated comment for more
+	 * information.
+	 */
+
+	/** @properties: property tracking for this colorop */
+	struct drm_object_properties properties;
+
+};
+
+#define obj_to_colorop(x) container_of(x, struct drm_colorop, base)
+
+/**
+ * drm_colorop_find - look up a Colorop object from its ID
+ * @dev: DRM device
+ * @file_priv: drm file to check for lease against.
+ * @id: &drm_mode_object ID
+ *
+ * This can be used to look up a Colorop from its userspace ID. Only used by
+ * drivers for legacy IOCTLs and interface, nowadays extensions to the KMS
+ * userspace interface should be done using &drm_property.
+ */
+static inline struct drm_colorop *drm_colorop_find(struct drm_device *dev,
+						   struct drm_file *file_priv,
+						   uint32_t id)
+{
+	struct drm_mode_object *mo;
+
+	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_COLOROP);
+	return mo ? obj_to_colorop(mo) : NULL;
+}
+
+struct drm_colorop_state *
+drm_atomic_helper_colorop_duplicate_state(struct drm_colorop *colorop);
+
+void drm_colorop_atomic_destroy_state(struct drm_colorop *colorop,
+				      struct drm_colorop_state *state);
+
+/**
+ * drm_colorop_reset - reset colorop atomic state
+ * @colorop: drm colorop
+ *
+ * Resets the atomic state for @colorop by freeing the state pointer (which might
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_colorop_reset(struct drm_colorop *colorop);
+
+/**
+ * drm_colorop_index - find the index of a registered colorop
+ * @colorop: colorop to find index for
+ *
+ * Given a registered colorop, return the index of that colorop within a DRM
+ * device's list of colorops.
+ */
+static inline unsigned int drm_colorop_index(const struct drm_colorop *colorop)
+{
+	return colorop->index;
+}
+
+#define drm_for_each_colorop(colorop, dev) \
+	list_for_each_entry(colorop, &(dev)->mode_config.colorop_list, head)
+
+#endif /* __DRM_COLOROP_H__ */

include/drm/drm_mode_config.h

@@ -500,6 +500,24 @@ struct drm_mode_config {
 	 */
 	struct raw_spinlock panic_lock;
 
+	/**
+	 * @num_colorop:
+	 *
+	 * Number of colorop objects on this device.
+	 * This is invariant over the lifetime of a device and hence doesn't
+	 * need any locks.
+	 */
+	int num_colorop;
+
+	/**
+	 * @colorop_list:
+	 *
+	 * List of colorop objects linked with &drm_colorop.head. This is
+	 * invariant over the lifetime of a device and hence doesn't need any
+	 * locks.
+	 */
+	struct list_head colorop_list;
+
 	/**
 	 * @num_crtc:
 	 *

include/drm/drm_plane.h

@@ -243,6 +243,14 @@ struct drm_plane_state {
 	 */
 	enum drm_scaling_filter scaling_filter;
 
+	/**
+	 * @color_pipeline:
+	 *
+	 * The first colorop of the active color pipeline, or NULL, if no
+	 * color pipeline is active.
+	 */
+	struct drm_colorop *color_pipeline;
+
 	/**
 	 * @commit: Tracks the pending commit to prevent use-after-free conditions,
 	 * and for async plane updates.