kernel/drivers/gpu/drm/drm_atomic_state_helper.c

/*
 * Copyright (C) 2018 Intel Corp.
 *
 * 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:
 * Rob Clark <robdclark@gmail.com>
 * Daniel Vetter <daniel.vetter@ffwll.ch>
 */

#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_plane.h>
#include <drm/drm_connector.h>
#include <drm/drm_atomic.h>
#include <drm/drm_device.h>

#include <linux/slab.h>
#include <linux/dma-fence.h>

/**
 * DOC: atomic state reset and initialization
 *
 * Both the drm core and the atomic helpers assume that there is always the full
 * and correct atomic software state for all connectors, CRTCs and planes
 * available. Which is a bit a problem on driver load and also after system
 * suspend. One way to solve this is to have a hardware state read-out
 * infrastructure which reconstructs the full software state (e.g. the i915
 * driver).
 *
 * The simpler solution is to just reset the software state to everything off,
 * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
 * the atomic helpers provide default reset implementations for all hooks.
 *
 * On the upside the precise state tracking of atomic simplifies system suspend
 * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
 * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
 * For other drivers the building blocks are split out, see the documentation
 * for these functions.
 */

/**
 * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
 * @crtc: drm CRTC
 *
 * Resets the atomic state for @crtc by freeing the state pointer (which might
 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 */
void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
{
	if (crtc->state)
		__drm_atomic_helper_crtc_destroy_state(crtc->state);

	kfree(crtc->state);
	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);

	if (crtc->state)
		crtc->state->crtc = crtc;
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);

/**
 * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
 * @crtc: CRTC object
 * @state: atomic CRTC state
 *
 * Copies atomic state from a CRTC's current state and resets inferred values.
 * This is useful for drivers that subclass the CRTC state.
 */
void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
					      struct drm_crtc_state *state)
{
	memcpy(state, crtc->state, sizeof(*state));

	if (state->mode_blob)
		drm_property_blob_get(state->mode_blob);
	if (state->degamma_lut)
		drm_property_blob_get(state->degamma_lut);
	if (state->ctm)
		drm_property_blob_get(state->ctm);
	if (state->gamma_lut)
		drm_property_blob_get(state->gamma_lut);
	state->mode_changed = false;
	state->active_changed = false;
	state->planes_changed = false;
	state->connectors_changed = false;
	state->color_mgmt_changed = false;
	state->zpos_changed = false;
	state->commit = NULL;
	state->event = NULL;
	state->pageflip_flags = 0;
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);

/**
 * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
 * @crtc: drm CRTC
 *
 * Default CRTC state duplicate hook for drivers which don't have their own
 * subclassed CRTC state structure.
 */
struct drm_crtc_state *
drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
{
	struct drm_crtc_state *state;

	if (WARN_ON(!crtc->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_crtc_duplicate_state(crtc, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);

/**
 * __drm_atomic_helper_crtc_destroy_state - release CRTC state
 * @state: CRTC state object to release
 *
 * Releases all resources stored in the CRTC state without actually freeing
 * the memory of the CRTC state. This is useful for drivers that subclass the
 * CRTC state.
 */
void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
{
	if (state->commit) {
		/*
		 * In the event that a non-blocking commit returns
		 * -ERESTARTSYS before the commit_tail work is queued, we will
		 * have an extra reference to the commit object. Release it, if
		 * the event has not been consumed by the worker.
		 *
		 * state->event may be freed, so we can't directly look at
		 * state->event->base.completion.
		 */
		if (state->event && state->commit->abort_completion)
			drm_crtc_commit_put(state->commit);

		kfree(state->commit->event);
		state->commit->event = NULL;

		drm_crtc_commit_put(state->commit);
	}

	drm_property_blob_put(state->mode_blob);
	drm_property_blob_put(state->degamma_lut);
	drm_property_blob_put(state->ctm);
	drm_property_blob_put(state->gamma_lut);
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);

/**
 * drm_atomic_helper_crtc_destroy_state - default state destroy hook
 * @crtc: drm CRTC
 * @state: CRTC state object to release
 *
 * Default CRTC state destroy hook for drivers which don't have their own
 * subclassed CRTC state structure.
 */
void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
					  struct drm_crtc_state *state)
{
	__drm_atomic_helper_crtc_destroy_state(state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);

/**
 * __drm_atomic_helper_plane_reset - resets planes state to default values
 * @plane: plane object, must not be NULL
 * @state: atomic plane state, must not be NULL
 *
 * Initializes plane state to default. This is useful for drivers that subclass
 * the plane state.
 */
void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
				     struct drm_plane_state *state)
{
	state->plane = plane;
	state->rotation = DRM_MODE_ROTATE_0;

	state->alpha = DRM_BLEND_ALPHA_OPAQUE;
	state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;

	plane->state = state;
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);

/**
 * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
 * @plane: drm plane
 *
 * Resets the atomic state for @plane by freeing the state pointer (which might
 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 */
void drm_atomic_helper_plane_reset(struct drm_plane *plane)
{
	if (plane->state)
		__drm_atomic_helper_plane_destroy_state(plane->state);

	kfree(plane->state);
	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
	if (plane->state)
		__drm_atomic_helper_plane_reset(plane, plane->state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_reset);

/**
 * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
 * @plane: plane object
 * @state: atomic plane state
 *
 * Copies atomic state from a plane's current state. This is useful for
 * drivers that subclass the plane state.
 */
void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
					       struct drm_plane_state *state)
{
	memcpy(state, plane->state, sizeof(*state));

	if (state->fb)
		drm_framebuffer_get(state->fb);

	state->fence = NULL;
	state->commit = NULL;
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);

/**
 * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
 * @plane: drm plane
 *
 * Default plane state duplicate hook for drivers which don't have their own
 * subclassed plane state structure.
 */
struct drm_plane_state *
drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
{
	struct drm_plane_state *state;

	if (WARN_ON(!plane->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_plane_duplicate_state(plane, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);

/**
 * __drm_atomic_helper_plane_destroy_state - release plane state
 * @state: plane state object to release
 *
 * Releases all resources stored in the plane state without actually freeing
 * the memory of the plane state. This is useful for drivers that subclass the
 * plane state.
 */
void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
{
	if (state->fb)
		drm_framebuffer_put(state->fb);

	if (state->fence)
		dma_fence_put(state->fence);

	if (state->commit)
		drm_crtc_commit_put(state->commit);
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);

/**
 * drm_atomic_helper_plane_destroy_state - default state destroy hook
 * @plane: drm plane
 * @state: plane state object to release
 *
 * Default plane state destroy hook for drivers which don't have their own
 * subclassed plane state structure.
 */
void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
					   struct drm_plane_state *state)
{
	__drm_atomic_helper_plane_destroy_state(state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);

/**
 * __drm_atomic_helper_connector_reset - reset state on connector
 * @connector: drm connector
 * @conn_state: connector state to assign
 *
 * Initializes the newly allocated @conn_state and assigns it to
 * the &drm_conector->state pointer of @connector, usually required when
 * initializing the drivers or when called from the &drm_connector_funcs.reset
 * hook.
 *
 * This is useful for drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_reset(struct drm_connector *connector,
				    struct drm_connector_state *conn_state)
{
	if (conn_state)
		conn_state->connector = connector;

	connector->state = conn_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);

/**
 * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
 * @connector: drm connector
 *
 * Resets the atomic state for @connector by freeing the state pointer (which
 * might be NULL, e.g. at driver load time) and allocating a new empty state
 * object.
 */
void drm_atomic_helper_connector_reset(struct drm_connector *connector)
{
	struct drm_connector_state *conn_state =
		kzalloc(sizeof(*conn_state), GFP_KERNEL);

	if (connector->state)
		__drm_atomic_helper_connector_destroy_state(connector->state);

	kfree(connector->state);
	__drm_atomic_helper_connector_reset(connector, conn_state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_reset);

/**
 * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
 * @connector: connector object
 * @state: atomic connector state
 *
 * Copies atomic state from a connector's current state. This is useful for
 * drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
					    struct drm_connector_state *state)
{
	memcpy(state, connector->state, sizeof(*state));
	if (state->crtc)
		drm_connector_get(connector);
	state->commit = NULL;

	/* Don't copy over a writeback job, they are used only once */
	state->writeback_job = NULL;
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);

/**
 * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
 * @connector: drm connector
 *
 * Default connector state duplicate hook for drivers which don't have their own
 * subclassed connector state structure.
 */
struct drm_connector_state *
drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
{
	struct drm_connector_state *state;

	if (WARN_ON(!connector->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_connector_duplicate_state(connector, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);

/**
 * drm_atomic_helper_duplicate_state - duplicate an atomic state object
 * @dev: DRM device
 * @ctx: lock acquisition context
 *
 * Makes a copy of the current atomic state by looping over all objects and
 * duplicating their respective states. This is used for example by suspend/
 * resume support code to save the state prior to suspend such that it can
 * be restored upon resume.
 *
 * Note that this treats atomic state as persistent between save and restore.
 * Drivers must make sure that this is possible and won't result in confusion
 * or erroneous behaviour.
 *
 * Note that if callers haven't already acquired all modeset locks this might
 * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
 *
 * Returns:
 * A pointer to the copy of the atomic state object on success or an
 * ERR_PTR()-encoded error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 */
struct drm_atomic_state *
drm_atomic_helper_duplicate_state(struct drm_device *dev,
				  struct drm_modeset_acquire_ctx *ctx)
{
	struct drm_atomic_state *state;
	struct drm_connector *conn;
	struct drm_connector_list_iter conn_iter;
	struct drm_plane *plane;
	struct drm_crtc *crtc;
	int err = 0;

	state = drm_atomic_state_alloc(dev);
	if (!state)
		return ERR_PTR(-ENOMEM);

	state->acquire_ctx = ctx;

	drm_for_each_crtc(crtc, dev) {
		struct drm_crtc_state *crtc_state;

		crtc_state = drm_atomic_get_crtc_state(state, crtc);
		if (IS_ERR(crtc_state)) {
			err = PTR_ERR(crtc_state);
			goto free;
		}
	}

	drm_for_each_plane(plane, dev) {
		struct drm_plane_state *plane_state;

		plane_state = drm_atomic_get_plane_state(state, plane);
		if (IS_ERR(plane_state)) {
			err = PTR_ERR(plane_state);
			goto free;
		}
	}

	drm_connector_list_iter_begin(dev, &conn_iter);
	drm_for_each_connector_iter(conn, &conn_iter) {
		struct drm_connector_state *conn_state;

		conn_state = drm_atomic_get_connector_state(state, conn);
		if (IS_ERR(conn_state)) {
			err = PTR_ERR(conn_state);
			drm_connector_list_iter_end(&conn_iter);
			goto free;
		}
	}
	drm_connector_list_iter_end(&conn_iter);

	/* clear the acquire context so that it isn't accidentally reused */
	state->acquire_ctx = NULL;

free:
	if (err < 0) {
		drm_atomic_state_put(state);
		state = ERR_PTR(err);
	}

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);

/**
 * __drm_atomic_helper_connector_destroy_state - release connector state
 * @state: connector state object to release
 *
 * Releases all resources stored in the connector state without actually
 * freeing the memory of the connector state. This is useful for drivers that
 * subclass the connector state.
 */
void
__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
{
	if (state->crtc)
		drm_connector_put(state->connector);

	if (state->commit)
		drm_crtc_commit_put(state->commit);
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);

/**
 * drm_atomic_helper_connector_destroy_state - default state destroy hook
 * @connector: drm connector
 * @state: connector state object to release
 *
 * Default connector state destroy hook for drivers which don't have their own
 * subclassed connector state structure.
 */
void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
					  struct drm_connector_state *state)
{
	__drm_atomic_helper_connector_destroy_state(state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);

/**
 * drm_atomic_helper_legacy_gamma_set - set the legacy gamma correction table
 * @crtc: CRTC object
 * @red: red correction table
 * @green: green correction table
 * @blue: green correction table
 * @size: size of the tables
 * @ctx: lock acquire context
 *
 * Implements support for legacy gamma correction table for drivers
 * that support color management through the DEGAMMA_LUT/GAMMA_LUT
 * properties. See drm_crtc_enable_color_mgmt() and the containing chapter for
 * how the atomic color management and gamma tables work.
 */
int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
				       u16 *red, u16 *green, u16 *blue,
				       uint32_t size,
				       struct drm_modeset_acquire_ctx *ctx)
{
	struct drm_device *dev = crtc->dev;
	struct drm_atomic_state *state;
	struct drm_crtc_state *crtc_state;
	struct drm_property_blob *blob = NULL;
	struct drm_color_lut *blob_data;
	int i, ret = 0;
	bool replaced;

	state = drm_atomic_state_alloc(crtc->dev);
	if (!state)
		return -ENOMEM;

	blob = drm_property_create_blob(dev,
					sizeof(struct drm_color_lut) * size,
					NULL);
	if (IS_ERR(blob)) {
		ret = PTR_ERR(blob);
		blob = NULL;
		goto fail;
	}

	/* Prepare GAMMA_LUT with the legacy values. */
	blob_data = blob->data;
	for (i = 0; i < size; i++) {
		blob_data[i].red = red[i];
		blob_data[i].green = green[i];
		blob_data[i].blue = blue[i];
	}

	state->acquire_ctx = ctx;
	crtc_state = drm_atomic_get_crtc_state(state, crtc);
	if (IS_ERR(crtc_state)) {
		ret = PTR_ERR(crtc_state);
		goto fail;
	}

	/* Reset DEGAMMA_LUT and CTM properties. */
	replaced  = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
	crtc_state->color_mgmt_changed |= replaced;

	ret = drm_atomic_commit(state);

fail:
	drm_atomic_state_put(state);
	drm_property_blob_put(blob);
	return ret;
}
EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);

/**
 * __drm_atomic_helper_private_duplicate_state - copy atomic private state
 * @obj: CRTC object
 * @state: new private object state
 *
 * Copies atomic state from a private objects's current state and resets inferred values.
 * This is useful for drivers that subclass the private state.
 */
void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
						     struct drm_private_state *state)
{
	memcpy(state, obj->state, sizeof(*state));
}
EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);