linux/drivers/gpu/drm/drm_atomic_helper.c

/*
 * Copyright (C) 2014 Red Hat
 * Copyright (C) 2014 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 <[email protected]>
 * Daniel Vetter <[email protected]>
 */

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

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_atomic_uapi.h>
#include <drm/drm_blend.h>
#include <drm/drm_bridge.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_panic.h>
#include <drm/drm_print.h>
#include <drm/drm_self_refresh_helper.h>
#include <drm/drm_vblank.h>
#include <drm/drm_writeback.h>

#include "drm_crtc_helper_internal.h"
#include "drm_crtc_internal.h"

/**
 * DOC: overview
 *
 * This helper library provides implementations of check and commit functions on
 * top of the CRTC modeset helper callbacks and the plane helper callbacks. It
 * also provides convenience implementations for the atomic state handling
 * callbacks for drivers which don't need to subclass the drm core structures to
 * add their own additional internal state.
 *
 * This library also provides default implementations for the check callback in
 * drm_atomic_helper_check() and for the commit callback with
 * drm_atomic_helper_commit(). But the individual stages and callbacks are
 * exposed to allow drivers to mix and match and e.g. use the plane helpers only
 * together with a driver private modeset implementation.
 *
 * This library also provides implementations for all the legacy driver
 * interfaces on top of the atomic interface. See drm_atomic_helper_set_config(),
 * drm_atomic_helper_disable_plane(), and the various functions to implement
 * set_property callbacks. New drivers must not implement these functions
 * themselves but must use the provided helpers.
 *
 * The atomic helper uses the same function table structures as all other
 * modesetting helpers. See the documentation for &struct drm_crtc_helper_funcs,
 * struct &drm_encoder_helper_funcs and &struct drm_connector_helper_funcs. It
 * also shares the &struct drm_plane_helper_funcs function table with the plane
 * helpers.
 */
static void
drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
				struct drm_plane_state *old_plane_state,
				struct drm_plane_state *plane_state,
				struct drm_plane *plane)
{}

static int handle_conflicting_encoders(struct drm_atomic_state *state,
				       bool disable_conflicting_encoders)
{}

static void
set_best_encoder(struct drm_atomic_state *state,
		 struct drm_connector_state *conn_state,
		 struct drm_encoder *encoder)
{}

static void
steal_encoder(struct drm_atomic_state *state,
	      struct drm_encoder *encoder)
{}

static int
update_connector_routing(struct drm_atomic_state *state,
			 struct drm_connector *connector,
			 struct drm_connector_state *old_connector_state,
			 struct drm_connector_state *new_connector_state,
			 bool added_by_user)
{}

static int
mode_fixup(struct drm_atomic_state *state)
{}

static enum drm_mode_status mode_valid_path(struct drm_connector *connector,
					    struct drm_encoder *encoder,
					    struct drm_crtc *crtc,
					    const struct drm_display_mode *mode)
{}

static int
mode_valid(struct drm_atomic_state *state)
{}

/**
 * drm_atomic_helper_check_modeset - validate state object for modeset changes
 * @dev: DRM device
 * @state: the driver state object
 *
 * Check the state object to see if the requested state is physically possible.
 * This does all the CRTC and connector related computations for an atomic
 * update and adds any additional connectors needed for full modesets. It calls
 * the various per-object callbacks in the follow order:
 *
 * 1. &drm_connector_helper_funcs.atomic_best_encoder for determining the new encoder.
 * 2. &drm_connector_helper_funcs.atomic_check to validate the connector state.
 * 3. If it's determined a modeset is needed then all connectors on the affected
 *    CRTC are added and &drm_connector_helper_funcs.atomic_check is run on them.
 * 4. &drm_encoder_helper_funcs.mode_valid, &drm_bridge_funcs.mode_valid and
 *    &drm_crtc_helper_funcs.mode_valid are called on the affected components.
 * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
 * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
 *    This function is only called when the encoder will be part of a configured CRTC,
 *    it must not be used for implementing connector property validation.
 *    If this function is NULL, &drm_atomic_encoder_helper_funcs.mode_fixup is called
 *    instead.
 * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with CRTC constraints.
 *
 * &drm_crtc_state.mode_changed is set when the input mode is changed.
 * &drm_crtc_state.connectors_changed is set when a connector is added or
 * removed from the CRTC.  &drm_crtc_state.active_changed is set when
 * &drm_crtc_state.active changes, which is used for DPMS.
 * &drm_crtc_state.no_vblank is set from the result of drm_dev_has_vblank().
 * See also: drm_atomic_crtc_needs_modeset()
 *
 * IMPORTANT:
 *
 * Drivers which set &drm_crtc_state.mode_changed (e.g. in their
 * &drm_plane_helper_funcs.atomic_check hooks if a plane update can't be done
 * without a full modeset) _must_ call this function after that change. It is
 * permitted to call this function multiple times for the same update, e.g.
 * when the &drm_crtc_helper_funcs.atomic_check functions depend upon the
 * adjusted dotclock for fifo space allocation and watermark computation.
 *
 * RETURNS:
 * Zero for success or -errno
 */
int
drm_atomic_helper_check_modeset(struct drm_device *dev,
				struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_check_wb_connector_state() - Check writeback connector state
 * @connector: corresponding connector
 * @state: the driver state object
 *
 * Checks if the writeback connector state is valid, and returns an error if it
 * isn't.
 *
 * RETURNS:
 * Zero for success or -errno
 */
int
drm_atomic_helper_check_wb_connector_state(struct drm_connector *connector,
					   struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_check_plane_state() - Check plane state for validity
 * @plane_state: plane state to check
 * @crtc_state: CRTC state to check
 * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
 * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
 * @can_position: is it legal to position the plane such that it
 *                doesn't cover the entire CRTC?  This will generally
 *                only be false for primary planes.
 * @can_update_disabled: can the plane be updated while the CRTC
 *                       is disabled?
 *
 * Checks that a desired plane update is valid, and updates various
 * bits of derived state (clipped coordinates etc.). Drivers that provide
 * their own plane handling rather than helper-provided implementations may
 * still wish to call this function to avoid duplication of error checking
 * code.
 *
 * RETURNS:
 * Zero if update appears valid, error code on failure
 */
int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
					const struct drm_crtc_state *crtc_state,
					int min_scale,
					int max_scale,
					bool can_position,
					bool can_update_disabled)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_check_crtc_primary_plane() - Check CRTC state for primary plane
 * @crtc_state: CRTC state to check
 *
 * Checks that a CRTC has at least one primary plane attached to it, which is
 * a requirement on some hardware. Note that this only involves the CRTC side
 * of the test. To test if the primary plane is visible or if it can be updated
 * without the CRTC being enabled, use drm_atomic_helper_check_plane_state() in
 * the plane's atomic check.
 *
 * RETURNS:
 * 0 if a primary plane is attached to the CRTC, or an error code otherwise
 */
int drm_atomic_helper_check_crtc_primary_plane(struct drm_crtc_state *crtc_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_check_planes - validate state object for planes changes
 * @dev: DRM device
 * @state: the driver state object
 *
 * Check the state object to see if the requested state is physically possible.
 * This does all the plane update related checks using by calling into the
 * &drm_crtc_helper_funcs.atomic_check and &drm_plane_helper_funcs.atomic_check
 * hooks provided by the driver.
 *
 * It also sets &drm_crtc_state.planes_changed to indicate that a CRTC has
 * updated planes.
 *
 * RETURNS:
 * Zero for success or -errno
 */
int
drm_atomic_helper_check_planes(struct drm_device *dev,
			       struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_check - validate state object
 * @dev: DRM device
 * @state: the driver state object
 *
 * Check the state object to see if the requested state is physically possible.
 * Only CRTCs and planes have check callbacks, so for any additional (global)
 * checking that a driver needs it can simply wrap that around this function.
 * Drivers without such needs can directly use this as their
 * &drm_mode_config_funcs.atomic_check callback.
 *
 * This just wraps the two parts of the state checking for planes and modeset
 * state in the default order: First it calls drm_atomic_helper_check_modeset()
 * and then drm_atomic_helper_check_planes(). The assumption is that the
 * @drm_plane_helper_funcs.atomic_check and @drm_crtc_helper_funcs.atomic_check
 * functions depend upon an updated adjusted_mode.clock to e.g. properly compute
 * watermarks.
 *
 * Note that zpos normalization will add all enable planes to the state which
 * might not desired for some drivers.
 * For example enable/disable of a cursor plane which have fixed zpos value
 * would trigger all other enabled planes to be forced to the state change.
 *
 * RETURNS:
 * Zero for success or -errno
 */
int drm_atomic_helper_check(struct drm_device *dev,
			    struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

static bool
crtc_needs_disable(struct drm_crtc_state *old_state,
		   struct drm_crtc_state *new_state)
{}

static void
disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
{}

/**
 * drm_atomic_helper_update_legacy_modeset_state - update legacy modeset state
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function updates all the various legacy modeset state pointers in
 * connectors, encoders and CRTCs.
 *
 * Drivers can use this for building their own atomic commit if they don't have
 * a pure helper-based modeset implementation.
 *
 * Since these updates are not synchronized with lockings, only code paths
 * called from &drm_mode_config_helper_funcs.atomic_commit_tail can look at the
 * legacy state filled out by this helper. Defacto this means this helper and
 * the legacy state pointers are only really useful for transitioning an
 * existing driver to the atomic world.
 */
void
drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
					      struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_calc_timestamping_constants - update vblank timestamping constants
 * @state: atomic state object
 *
 * Updates the timestamping constants used for precise vblank timestamps
 * by calling drm_calc_timestamping_constants() for all enabled crtcs in @state.
 */
void drm_atomic_helper_calc_timestamping_constants(struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

static void
crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
{}

/**
 * drm_atomic_helper_commit_modeset_disables - modeset commit to disable outputs
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function shuts down all the outputs that need to be shut down and
 * prepares them (if required) with the new mode.
 *
 * For compatibility with legacy CRTC helpers this should be called before
 * drm_atomic_helper_commit_planes(), which is what the default commit function
 * does. But drivers with different needs can group the modeset commits together
 * and do the plane commits at the end. This is useful for drivers doing runtime
 * PM since planes updates then only happen when the CRTC is actually enabled.
 */
void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev,
					       struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

static void drm_atomic_helper_commit_writebacks(struct drm_device *dev,
						struct drm_atomic_state *old_state)
{}

/**
 * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function enables all the outputs with the new configuration which had to
 * be turned off for the update.
 *
 * For compatibility with legacy CRTC helpers this should be called after
 * drm_atomic_helper_commit_planes(), which is what the default commit function
 * does. But drivers with different needs can group the modeset commits together
 * and do the plane commits at the end. This is useful for drivers doing runtime
 * PM since planes updates then only happen when the CRTC is actually enabled.
 */
void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
					      struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/*
 * For atomic updates which touch just a single CRTC, calculate the time of the
 * next vblank, and inform all the fences of the deadline.
 */
static void set_fence_deadline(struct drm_device *dev,
			       struct drm_atomic_state *state)
{}

/**
 * drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
 * @dev: DRM device
 * @state: atomic state object with old state structures
 * @pre_swap: If true, do an interruptible wait, and @state is the new state.
 *	Otherwise @state is the old state.
 *
 * For implicit sync, driver should fish the exclusive fence out from the
 * incoming fb's and stash it in the drm_plane_state.  This is called after
 * drm_atomic_helper_swap_state() so it uses the current plane state (and
 * just uses the atomic state to find the changed planes)
 *
 * Note that @pre_swap is needed since the point where we block for fences moves
 * around depending upon whether an atomic commit is blocking or
 * non-blocking. For non-blocking commit all waiting needs to happen after
 * drm_atomic_helper_swap_state() is called, but for blocking commits we want
 * to wait **before** we do anything that can't be easily rolled back. That is
 * before we call drm_atomic_helper_swap_state().
 *
 * Returns zero if success or < 0 if dma_fence_wait() fails.
 */
int drm_atomic_helper_wait_for_fences(struct drm_device *dev,
				      struct drm_atomic_state *state,
				      bool pre_swap)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_wait_for_vblanks - wait for vblank on CRTCs
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * Helper to, after atomic commit, wait for vblanks on all affected
 * CRTCs (ie. before cleaning up old framebuffers using
 * drm_atomic_helper_cleanup_planes()). It will only wait on CRTCs where the
 * framebuffers have actually changed to optimize for the legacy cursor and
 * plane update use-case.
 *
 * Drivers using the nonblocking commit tracking support initialized by calling
 * drm_atomic_helper_setup_commit() should look at
 * drm_atomic_helper_wait_for_flip_done() as an alternative.
 */
void
drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
		struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_wait_for_flip_done - wait for all page flips to be done
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * Helper to, after atomic commit, wait for page flips on all affected
 * crtcs (ie. before cleaning up old framebuffers using
 * drm_atomic_helper_cleanup_planes()). Compared to
 * drm_atomic_helper_wait_for_vblanks() this waits for the completion on all
 * CRTCs, assuming that cursors-only updates are signalling their completion
 * immediately (or using a different path).
 *
 * This requires that drivers use the nonblocking commit tracking support
 * initialized using drm_atomic_helper_setup_commit().
 */
void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
					  struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit_tail - commit atomic update to hardware
 * @old_state: atomic state object with old state structures
 *
 * This is the default implementation for the
 * &drm_mode_config_helper_funcs.atomic_commit_tail hook, for drivers
 * that do not support runtime_pm or do not need the CRTC to be
 * enabled to perform a commit. Otherwise, see
 * drm_atomic_helper_commit_tail_rpm().
 *
 * Note that the default ordering of how the various stages are called is to
 * match the legacy modeset helper library closest.
 */
void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit_tail_rpm - commit atomic update to hardware
 * @old_state: new modeset state to be committed
 *
 * This is an alternative implementation for the
 * &drm_mode_config_helper_funcs.atomic_commit_tail hook, for drivers
 * that support runtime_pm or need the CRTC to be enabled to perform a
 * commit. Otherwise, one should use the default implementation
 * drm_atomic_helper_commit_tail().
 */
void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

static void commit_tail(struct drm_atomic_state *old_state)
{}

static void commit_work(struct work_struct *work)
{}

/**
 * drm_atomic_helper_async_check - check if state can be committed asynchronously
 * @dev: DRM device
 * @state: the driver state object
 *
 * This helper will check if it is possible to commit the state asynchronously.
 * Async commits are not supposed to swap the states like normal sync commits
 * but just do in-place changes on the current state.
 *
 * It will return 0 if the commit can happen in an asynchronous fashion or error
 * if not. Note that error just mean it can't be committed asynchronously, if it
 * fails the commit should be treated like a normal synchronous commit.
 */
int drm_atomic_helper_async_check(struct drm_device *dev,
				   struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_async_commit - commit state asynchronously
 * @dev: DRM device
 * @state: the driver state object
 *
 * This function commits a state asynchronously, i.e., not vblank
 * synchronized. It should be used on a state only when
 * drm_atomic_async_check() succeeds. Async commits are not supposed to swap
 * the states like normal sync commits, but just do in-place changes on the
 * current state.
 *
 * TODO: Implement full swap instead of doing in-place changes.
 */
void drm_atomic_helper_async_commit(struct drm_device *dev,
				    struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit - commit validated state object
 * @dev: DRM device
 * @state: the driver state object
 * @nonblock: whether nonblocking behavior is requested.
 *
 * This function commits a with drm_atomic_helper_check() pre-validated state
 * object. This can still fail when e.g. the framebuffer reservation fails. This
 * function implements nonblocking commits, using
 * drm_atomic_helper_setup_commit() and related functions.
 *
 * Committing the actual hardware state is done through the
 * &drm_mode_config_helper_funcs.atomic_commit_tail callback, or its default
 * implementation drm_atomic_helper_commit_tail().
 *
 * RETURNS:
 * Zero for success or -errno.
 */
int drm_atomic_helper_commit(struct drm_device *dev,
			     struct drm_atomic_state *state,
			     bool nonblock)
{}
EXPORT_SYMBOL();

/**
 * DOC: implementing nonblocking commit
 *
 * Nonblocking atomic commits should use struct &drm_crtc_commit to sequence
 * different operations against each another. Locks, especially struct
 * &drm_modeset_lock, should not be held in worker threads or any other
 * asynchronous context used to commit the hardware state.
 *
 * drm_atomic_helper_commit() implements the recommended sequence for
 * nonblocking commits, using drm_atomic_helper_setup_commit() internally:
 *
 * 1. Run drm_atomic_helper_prepare_planes(). Since this can fail and we
 * need to propagate out of memory/VRAM errors to userspace, it must be called
 * synchronously.
 *
 * 2. Synchronize with any outstanding nonblocking commit worker threads which
 * might be affected by the new state update. This is handled by
 * drm_atomic_helper_setup_commit().
 *
 * Asynchronous workers need to have sufficient parallelism to be able to run
 * different atomic commits on different CRTCs in parallel. The simplest way to
 * achieve this is by running them on the &system_unbound_wq work queue. Note
 * that drivers are not required to split up atomic commits and run an
 * individual commit in parallel - userspace is supposed to do that if it cares.
 * But it might be beneficial to do that for modesets, since those necessarily
 * must be done as one global operation, and enabling or disabling a CRTC can
 * take a long time. But even that is not required.
 *
 * IMPORTANT: A &drm_atomic_state update for multiple CRTCs is sequenced
 * against all CRTCs therein. Therefore for atomic state updates which only flip
 * planes the driver must not get the struct &drm_crtc_state of unrelated CRTCs
 * in its atomic check code: This would prevent committing of atomic updates to
 * multiple CRTCs in parallel. In general, adding additional state structures
 * should be avoided as much as possible, because this reduces parallelism in
 * (nonblocking) commits, both due to locking and due to commit sequencing
 * requirements.
 *
 * 3. The software state is updated synchronously with
 * drm_atomic_helper_swap_state(). Doing this under the protection of all modeset
 * locks means concurrent callers never see inconsistent state. Note that commit
 * workers do not hold any locks; their access is only coordinated through
 * ordering. If workers would access state only through the pointers in the
 * free-standing state objects (currently not the case for any driver) then even
 * multiple pending commits could be in-flight at the same time.
 *
 * 4. Schedule a work item to do all subsequent steps, using the split-out
 * commit helpers: a) pre-plane commit b) plane commit c) post-plane commit and
 * then cleaning up the framebuffers after the old framebuffer is no longer
 * being displayed. The scheduled work should synchronize against other workers
 * using the &drm_crtc_commit infrastructure as needed. See
 * drm_atomic_helper_setup_commit() for more details.
 */

static int stall_checks(struct drm_crtc *crtc, bool nonblock)
{}

static void release_crtc_commit(struct completion *completion)
{}

static void init_commit(struct drm_crtc_commit *commit, struct drm_crtc *crtc)
{}

static struct drm_crtc_commit *
crtc_or_fake_commit(struct drm_atomic_state *state, struct drm_crtc *crtc)
{}

/**
 * drm_atomic_helper_setup_commit - setup possibly nonblocking commit
 * @state: new modeset state to be committed
 * @nonblock: whether nonblocking behavior is requested.
 *
 * This function prepares @state to be used by the atomic helper's support for
 * nonblocking commits. Drivers using the nonblocking commit infrastructure
 * should always call this function from their
 * &drm_mode_config_funcs.atomic_commit hook.
 *
 * Drivers that need to extend the commit setup to private objects can use the
 * &drm_mode_config_helper_funcs.atomic_commit_setup hook.
 *
 * To be able to use this support drivers need to use a few more helper
 * functions. drm_atomic_helper_wait_for_dependencies() must be called before
 * actually committing the hardware state, and for nonblocking commits this call
 * must be placed in the async worker. See also drm_atomic_helper_swap_state()
 * and its stall parameter, for when a driver's commit hooks look at the
 * &drm_crtc.state, &drm_plane.state or &drm_connector.state pointer directly.
 *
 * Completion of the hardware commit step must be signalled using
 * drm_atomic_helper_commit_hw_done(). After this step the driver is not allowed
 * to read or change any permanent software or hardware modeset state. The only
 * exception is state protected by other means than &drm_modeset_lock locks.
 * Only the free standing @state with pointers to the old state structures can
 * be inspected, e.g. to clean up old buffers using
 * drm_atomic_helper_cleanup_planes().
 *
 * At the very end, before cleaning up @state drivers must call
 * drm_atomic_helper_commit_cleanup_done().
 *
 * This is all implemented by in drm_atomic_helper_commit(), giving drivers a
 * complete and easy-to-use default implementation of the atomic_commit() hook.
 *
 * The tracking of asynchronously executed and still pending commits is done
 * using the core structure &drm_crtc_commit.
 *
 * By default there's no need to clean up resources allocated by this function
 * explicitly: drm_atomic_state_default_clear() will take care of that
 * automatically.
 *
 * Returns:
 * 0 on success. -EBUSY when userspace schedules nonblocking commits too fast,
 * -ENOMEM on allocation failures and -EINTR when a signal is pending.
 */
int drm_atomic_helper_setup_commit(struct drm_atomic_state *state,
				   bool nonblock)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_wait_for_dependencies - wait for required preceding commits
 * @old_state: atomic state object with old state structures
 *
 * This function waits for all preceding commits that touch the same CRTC as
 * @old_state to both be committed to the hardware (as signalled by
 * drm_atomic_helper_commit_hw_done()) and executed by the hardware (as signalled
 * by calling drm_crtc_send_vblank_event() on the &drm_crtc_state.event).
 *
 * This is part of the atomic helper support for nonblocking commits, see
 * drm_atomic_helper_setup_commit() for an overview.
 */
void drm_atomic_helper_wait_for_dependencies(struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_fake_vblank - fake VBLANK events if needed
 * @old_state: atomic state object with old state structures
 *
 * This function walks all CRTCs and fakes VBLANK events on those with
 * &drm_crtc_state.no_vblank set to true and &drm_crtc_state.event != NULL.
 * The primary use of this function is writeback connectors working in oneshot
 * mode and faking VBLANK events. In this case they only fake the VBLANK event
 * when a job is queued, and any change to the pipeline that does not touch the
 * connector is leading to timeouts when calling
 * drm_atomic_helper_wait_for_vblanks() or
 * drm_atomic_helper_wait_for_flip_done(). In addition to writeback
 * connectors, this function can also fake VBLANK events for CRTCs without
 * VBLANK interrupt.
 *
 * This is part of the atomic helper support for nonblocking commits, see
 * drm_atomic_helper_setup_commit() for an overview.
 */
void drm_atomic_helper_fake_vblank(struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit_hw_done - setup possible nonblocking commit
 * @old_state: atomic state object with old state structures
 *
 * This function is used to signal completion of the hardware commit step. After
 * this step the driver is not allowed to read or change any permanent software
 * or hardware modeset state. The only exception is state protected by other
 * means than &drm_modeset_lock locks.
 *
 * Drivers should try to postpone any expensive or delayed cleanup work after
 * this function is called.
 *
 * This is part of the atomic helper support for nonblocking commits, see
 * drm_atomic_helper_setup_commit() for an overview.
 */
void drm_atomic_helper_commit_hw_done(struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit_cleanup_done - signal completion of commit
 * @old_state: atomic state object with old state structures
 *
 * This signals completion of the atomic update @old_state, including any
 * cleanup work. If used, it must be called right before calling
 * drm_atomic_state_put().
 *
 * This is part of the atomic helper support for nonblocking commits, see
 * drm_atomic_helper_setup_commit() for an overview.
 */
void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_prepare_planes - prepare plane resources before commit
 * @dev: DRM device
 * @state: atomic state object with new state structures
 *
 * This function prepares plane state, specifically framebuffers, for the new
 * configuration, by calling &drm_plane_helper_funcs.prepare_fb. If any failure
 * is encountered this function will call &drm_plane_helper_funcs.cleanup_fb on
 * any already successfully prepared framebuffer.
 *
 * Returns:
 * 0 on success, negative error code on failure.
 */
int drm_atomic_helper_prepare_planes(struct drm_device *dev,
				     struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_unprepare_planes - release plane resources on aborts
 * @dev: DRM device
 * @state: atomic state object with old state structures
 *
 * This function cleans up plane state, specifically framebuffers, from the
 * atomic state. It undoes the effects of drm_atomic_helper_prepare_planes()
 * when aborting an atomic commit. For cleaning up after a successful commit
 * use drm_atomic_helper_cleanup_planes().
 */
void drm_atomic_helper_unprepare_planes(struct drm_device *dev,
					struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

static bool plane_crtc_active(const struct drm_plane_state *state)
{}

/**
 * drm_atomic_helper_commit_planes - commit plane state
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 * @flags: flags for committing plane state
 *
 * This function commits the new plane state using the plane and atomic helper
 * functions for planes and CRTCs. It assumes that the atomic state has already
 * been pushed into the relevant object state pointers, since this step can no
 * longer fail.
 *
 * It still requires the global state object @old_state to know which planes and
 * crtcs need to be updated though.
 *
 * Note that this function does all plane updates across all CRTCs in one step.
 * If the hardware can't support this approach look at
 * drm_atomic_helper_commit_planes_on_crtc() instead.
 *
 * Plane parameters can be updated by applications while the associated CRTC is
 * disabled. The DRM/KMS core will store the parameters in the plane state,
 * which will be available to the driver when the CRTC is turned on. As a result
 * most drivers don't need to be immediately notified of plane updates for a
 * disabled CRTC.
 *
 * Unless otherwise needed, drivers are advised to set the ACTIVE_ONLY flag in
 * @flags in order not to receive plane update notifications related to a
 * disabled CRTC. This avoids the need to manually ignore plane updates in
 * driver code when the driver and/or hardware can't or just don't need to deal
 * with updates on disabled CRTCs, for example when supporting runtime PM.
 *
 * Drivers may set the NO_DISABLE_AFTER_MODESET flag in @flags if the relevant
 * display controllers require to disable a CRTC's planes when the CRTC is
 * disabled. This function would skip the &drm_plane_helper_funcs.atomic_disable
 * call for a plane if the CRTC of the old plane state needs a modesetting
 * operation. Of course, the drivers need to disable the planes in their CRTC
 * disable callbacks since no one else would do that.
 *
 * The drm_atomic_helper_commit() default implementation doesn't set the
 * ACTIVE_ONLY flag to most closely match the behaviour of the legacy helpers.
 * This should not be copied blindly by drivers.
 */
void drm_atomic_helper_commit_planes(struct drm_device *dev,
				     struct drm_atomic_state *old_state,
				     uint32_t flags)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit_planes_on_crtc - commit plane state for a CRTC
 * @old_crtc_state: atomic state object with the old CRTC state
 *
 * This function commits the new plane state using the plane and atomic helper
 * functions for planes on the specific CRTC. It assumes that the atomic state
 * has already been pushed into the relevant object state pointers, since this
 * step can no longer fail.
 *
 * This function is useful when plane updates should be done CRTC-by-CRTC
 * instead of one global step like drm_atomic_helper_commit_planes() does.
 *
 * This function can only be savely used when planes are not allowed to move
 * between different CRTCs because this function doesn't handle inter-CRTC
 * dependencies. Callers need to ensure that either no such dependencies exist,
 * resolve them through ordering of commit calls or through some other means.
 */
void
drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_disable_planes_on_crtc - helper to disable CRTC's planes
 * @old_crtc_state: atomic state object with the old CRTC state
 * @atomic: if set, synchronize with CRTC's atomic_begin/flush hooks
 *
 * Disables all planes associated with the given CRTC. This can be
 * used for instance in the CRTC helper atomic_disable callback to disable
 * all planes.
 *
 * If the atomic-parameter is set the function calls the CRTC's
 * atomic_begin hook before and atomic_flush hook after disabling the
 * planes.
 *
 * It is a bug to call this function without having implemented the
 * &drm_plane_helper_funcs.atomic_disable plane hook.
 */
void
drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc_state *old_crtc_state,
					 bool atomic)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_cleanup_planes - cleanup plane resources after commit
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function cleans up plane state, specifically framebuffers, from the old
 * configuration. Hence the old configuration must be perserved in @old_state to
 * be able to call this function.
 *
 * This function may not be called on the new state when the atomic update
 * fails at any point after calling drm_atomic_helper_prepare_planes(). Use
 * drm_atomic_helper_unprepare_planes() in this case.
 */
void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
				      struct drm_atomic_state *old_state)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_swap_state - store atomic state into current sw state
 * @state: atomic state
 * @stall: stall for preceding commits
 *
 * This function stores the atomic state into the current state pointers in all
 * driver objects. It should be called after all failing steps have been done
 * and succeeded, but before the actual hardware state is committed.
 *
 * For cleanup and error recovery the current state for all changed objects will
 * be swapped into @state.
 *
 * With that sequence it fits perfectly into the plane prepare/cleanup sequence:
 *
 * 1. Call drm_atomic_helper_prepare_planes() with the staged atomic state.
 *
 * 2. Do any other steps that might fail.
 *
 * 3. Put the staged state into the current state pointers with this function.
 *
 * 4. Actually commit the hardware state.
 *
 * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
 * contains the old state. Also do any other cleanup required with that state.
 *
 * @stall must be set when nonblocking commits for this driver directly access
 * the &drm_plane.state, &drm_crtc.state or &drm_connector.state pointer. With
 * the current atomic helpers this is almost always the case, since the helpers
 * don't pass the right state structures to the callbacks.
 *
 * Returns:
 * Returns 0 on success. Can return -ERESTARTSYS when @stall is true and the
 * waiting for the previous commits has been interrupted.
 */
int drm_atomic_helper_swap_state(struct drm_atomic_state *state,
				  bool stall)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_update_plane - Helper for primary plane update using atomic
 * @plane: plane object to update
 * @crtc: owning CRTC of owning plane
 * @fb: framebuffer to flip onto plane
 * @crtc_x: x offset of primary plane on @crtc
 * @crtc_y: y offset of primary plane on @crtc
 * @crtc_w: width of primary plane rectangle on @crtc
 * @crtc_h: height of primary plane rectangle on @crtc
 * @src_x: x offset of @fb for panning
 * @src_y: y offset of @fb for panning
 * @src_w: width of source rectangle in @fb
 * @src_h: height of source rectangle in @fb
 * @ctx: lock acquire context
 *
 * Provides a default plane update handler using the atomic driver interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_helper_update_plane(struct drm_plane *plane,
				   struct drm_crtc *crtc,
				   struct drm_framebuffer *fb,
				   int crtc_x, int crtc_y,
				   unsigned int crtc_w, unsigned int crtc_h,
				   uint32_t src_x, uint32_t src_y,
				   uint32_t src_w, uint32_t src_h,
				   struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_disable_plane - Helper for primary plane disable using atomic
 * @plane: plane to disable
 * @ctx: lock acquire context
 *
 * Provides a default plane disable handler using the atomic driver interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_helper_disable_plane(struct drm_plane *plane,
				    struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_set_config - set a new config from userspace
 * @set: mode set configuration
 * @ctx: lock acquisition context
 *
 * Provides a default CRTC set_config handler using the atomic driver interface.
 *
 * NOTE: For backwards compatibility with old userspace this automatically
 * resets the "link-status" property to GOOD, to force any link
 * re-training. The SETCRTC ioctl does not define whether an update does
 * need a full modeset or just a plane update, hence we're allowed to do
 * that. See also drm_connector_set_link_status_property().
 *
 * Returns:
 * Returns 0 on success, negative errno numbers on failure.
 */
int drm_atomic_helper_set_config(struct drm_mode_set *set,
				 struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_disable_all - disable all currently active outputs
 * @dev: DRM device
 * @ctx: lock acquisition context
 *
 * Loops through all connectors, finding those that aren't turned off and then
 * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
 * that they are connected to.
 *
 * This is used for example in suspend/resume to disable all currently active
 * functions when suspending. If you just want to shut down everything at e.g.
 * driver unload, look at drm_atomic_helper_shutdown().
 *
 * 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:
 * 0 on success or a negative error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend(), drm_atomic_helper_resume() and
 * drm_atomic_helper_shutdown().
 */
int drm_atomic_helper_disable_all(struct drm_device *dev,
				  struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_shutdown - shutdown all CRTC
 * @dev: DRM device
 *
 * This shuts down all CRTC, which is useful for driver unloading. Shutdown on
 * suspend should instead be handled with drm_atomic_helper_suspend(), since
 * that also takes a snapshot of the modeset state to be restored on resume.
 *
 * This is just a convenience wrapper around drm_atomic_helper_disable_all(),
 * and it is the atomic version of drm_helper_force_disable_all().
 */
void drm_atomic_helper_shutdown(struct drm_device *dev)
{}
EXPORT_SYMBOL();

/**
 * 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)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_suspend - subsystem-level suspend helper
 * @dev: DRM device
 *
 * Duplicates the current atomic state, disables all active outputs and then
 * returns a pointer to the original atomic state to the caller. Drivers can
 * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
 * restore the output configuration that was active at the time the system
 * entered suspend.
 *
 * Note that it is potentially unsafe to use this. The atomic state object
 * returned by this function is assumed to be persistent. Drivers must ensure
 * that this holds true. Before calling this function, drivers must make sure
 * to suspend fbdev emulation so that nothing can be using the device.
 *
 * Returns:
 * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
 * encoded error code on failure. Drivers should store the returned atomic
 * state object and pass it to the drm_atomic_helper_resume() helper upon
 * resume.
 *
 * See also:
 * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
 * drm_atomic_helper_resume(), drm_atomic_helper_commit_duplicated_state()
 */
struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_commit_duplicated_state - commit duplicated state
 * @state: duplicated atomic state to commit
 * @ctx: pointer to acquire_ctx to use for commit.
 *
 * The state returned by drm_atomic_helper_duplicate_state() and
 * drm_atomic_helper_suspend() is partially invalid, and needs to
 * be fixed up before commit.
 *
 * Returns:
 * 0 on success or a negative error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend()
 */
int drm_atomic_helper_commit_duplicated_state(struct drm_atomic_state *state,
					      struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_resume - subsystem-level resume helper
 * @dev: DRM device
 * @state: atomic state to resume to
 *
 * Calls drm_mode_config_reset() to synchronize hardware and software states,
 * grabs all modeset locks and commits the atomic state object. This can be
 * used in conjunction with the drm_atomic_helper_suspend() helper to
 * implement suspend/resume for drivers that support atomic mode-setting.
 *
 * Returns:
 * 0 on success or a negative error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend()
 */
int drm_atomic_helper_resume(struct drm_device *dev,
			     struct drm_atomic_state *state)
{}
EXPORT_SYMBOL();

static int page_flip_common(struct drm_atomic_state *state,
			    struct drm_crtc *crtc,
			    struct drm_framebuffer *fb,
			    struct drm_pending_vblank_event *event,
			    uint32_t flags)
{}

/**
 * drm_atomic_helper_page_flip - execute a legacy page flip
 * @crtc: DRM CRTC
 * @fb: DRM framebuffer
 * @event: optional DRM event to signal upon completion
 * @flags: flip flags for non-vblank sync'ed updates
 * @ctx: lock acquisition context
 *
 * Provides a default &drm_crtc_funcs.page_flip implementation
 * using the atomic driver interface.
 *
 * Returns:
 * Returns 0 on success, negative errno numbers on failure.
 *
 * See also:
 * drm_atomic_helper_page_flip_target()
 */
int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
				struct drm_framebuffer *fb,
				struct drm_pending_vblank_event *event,
				uint32_t flags,
				struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_page_flip_target - do page flip on target vblank period.
 * @crtc: DRM CRTC
 * @fb: DRM framebuffer
 * @event: optional DRM event to signal upon completion
 * @flags: flip flags for non-vblank sync'ed updates
 * @target: specifying the target vblank period when the flip to take effect
 * @ctx: lock acquisition context
 *
 * Provides a default &drm_crtc_funcs.page_flip_target implementation.
 * Similar to drm_atomic_helper_page_flip() with extra parameter to specify
 * target vblank period to flip.
 *
 * Returns:
 * Returns 0 on success, negative errno numbers on failure.
 */
int drm_atomic_helper_page_flip_target(struct drm_crtc *crtc,
				       struct drm_framebuffer *fb,
				       struct drm_pending_vblank_event *event,
				       uint32_t flags,
				       uint32_t target,
				       struct drm_modeset_acquire_ctx *ctx)
{}
EXPORT_SYMBOL();

/**
 * drm_atomic_helper_bridge_propagate_bus_fmt() - Propagate output format to
 *						  the input end of a bridge
 * @bridge: bridge control structure
 * @bridge_state: new bridge state
 * @crtc_state: new CRTC state
 * @conn_state: new connector state
 * @output_fmt: tested output bus format
 * @num_input_fmts: will contain the size of the returned array
 *
 * This helper is a pluggable implementation of the
 * &drm_bridge_funcs.atomic_get_input_bus_fmts operation for bridges that don't
 * modify the bus configuration between their input and their output. It
 * returns an array of input formats with a single element set to @output_fmt.
 *
 * RETURNS:
 * a valid format array of size @num_input_fmts, or NULL if the allocation
 * failed
 */
u32 *
drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
					struct drm_bridge_state *bridge_state,
					struct drm_crtc_state *crtc_state,
					struct drm_connector_state *conn_state,
					u32 output_fmt,
					unsigned int *num_input_fmts)
{}
EXPORT_SYMBOL();