drivers/gpu/drm/msm/msm_atomic.c - linux-imx - Git at Google

 /*
  * Copyright (C) 2014 Red Hat
  * Author: Rob Clark <robdclark@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include "msm_drv.h"
 #include "msm_kms.h"
 #include "msm_gem.h"
 #include "msm_fence.h"

 struct msm_commit {
 	struct drm_device *dev;
 	struct drm_atomic_state *state;
 	struct work_struct work;
 	uint32_t crtc_mask;
 };

 static void commit_worker(struct work_struct *work);

 /* block until specified crtcs are no longer pending update, and
  * atomically mark them as pending update
  */
 static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
 {
 	int ret;

 	spin_lock(&priv->pending_crtcs_event.lock);
 	ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
 			!(priv->pending_crtcs & crtc_mask));
 	if (ret == 0) {
 		DBG("start: %08x", crtc_mask);
 		priv->pending_crtcs |= crtc_mask;
 	}
 	spin_unlock(&priv->pending_crtcs_event.lock);

 	return ret;
 }

 /* clear specified crtcs (no longer pending update)
  */
 static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
 {
 	spin_lock(&priv->pending_crtcs_event.lock);
 	DBG("end: %08x", crtc_mask);
 	priv->pending_crtcs &= ~crtc_mask;
 	wake_up_all_locked(&priv->pending_crtcs_event);
 	spin_unlock(&priv->pending_crtcs_event.lock);
 }

 static struct msm_commit *commit_init(struct drm_atomic_state *state)
 {
 	struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);

 	if (!c)
 		return NULL;

 	c->dev = state->dev;
 	c->state = state;

 	INIT_WORK(&c->work, commit_worker);

 	return c;
 }

 static void commit_destroy(struct msm_commit *c)
 {
 	end_atomic(c->dev->dev_private, c->crtc_mask);
 	kfree(c);
 }

 static void msm_atomic_wait_for_commit_done(struct drm_device *dev,
 		struct drm_atomic_state *old_state)
 {
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *new_crtc_state;
 	struct msm_drm_private *priv = old_state->dev->dev_private;
 	struct msm_kms *kms = priv->kms;
 	int i;

 	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
 		if (!new_crtc_state->active)
 			continue;

 		if (drm_crtc_vblank_get(crtc))
 			continue;

 		kms->funcs->wait_for_crtc_commit_done(kms, crtc);

 		drm_crtc_vblank_put(crtc);
 	}
 }

 /* The (potentially) asynchronous part of the commit.  At this point
  * nothing can fail short of armageddon.
  */
 static void complete_commit(struct msm_commit *c, bool async)
 {
 	struct drm_atomic_state *state = c->state;
 	struct drm_device *dev = state->dev;
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_kms *kms = priv->kms;

 	drm_atomic_helper_wait_for_fences(dev, state, false);

 	kms->funcs->prepare_commit(kms, state);

 	drm_atomic_helper_commit_modeset_disables(dev, state);

 	drm_atomic_helper_commit_planes(dev, state, 0);

 	drm_atomic_helper_commit_modeset_enables(dev, state);

 	/* NOTE: _wait_for_vblanks() only waits for vblank on
 	 * enabled CRTCs.  So we end up faulting when disabling
 	 * due to (potentially) unref'ing the outgoing fb's
 	 * before the vblank when the disable has latched.
 	 *
 	 * But if it did wait on disabled (or newly disabled)
 	 * CRTCs, that would be racy (ie. we could have missed
 	 * the irq.  We need some way to poll for pipe shut
 	 * down.  Or just live with occasionally hitting the
 	 * timeout in the CRTC disable path (which really should
 	 * not be critical path)
 	 */

 	msm_atomic_wait_for_commit_done(dev, state);

 	drm_atomic_helper_cleanup_planes(dev, state);

 	kms->funcs->complete_commit(kms, state);

 	drm_atomic_state_put(state);

 	commit_destroy(c);
 }

 static void commit_worker(struct work_struct *work)
 {
 	complete_commit(container_of(work, struct msm_commit, work), true);
 }

 /*
  * this func is identical to the drm_atomic_helper_check, but we keep this
  * because we might eventually need to have a more finegrained check
  * sequence without using the atomic helpers.
  *
  * In the past, we first called drm_atomic_helper_check_planes, and then
  * drm_atomic_helper_check_modeset. We needed this because the MDP5 plane's
  * ->atomic_check could update ->mode_changed for pixel format changes.
  * This, however isn't needed now because if there is a pixel format change,
  * we just assign a new hwpipe for it with a new SMP allocation. We might
  * eventually hit a condition where we would need to do a full modeset if
  * we run out of planes. There, we'd probably need to set mode_changed.
  */
 int msm_atomic_check(struct drm_device *dev,
 		     struct drm_atomic_state *state)
 {
 	int ret;

 	ret = drm_atomic_helper_check_modeset(dev, state);
 	if (ret)
 		return ret;

 	ret = drm_atomic_helper_check_planes(dev, state);
 	if (ret)
 		return ret;

 	return ret;
 }

 /**
  * drm_atomic_helper_commit - commit validated state object
  * @dev: DRM device
  * @state: the driver state object
  * @nonblock: nonblocking commit
  *
  * This function commits a with drm_atomic_helper_check() pre-validated state
  * object. This can still fail when e.g. the framebuffer reservation fails.
  *
  * RETURNS
  * Zero for success or -errno.
  */
 int msm_atomic_commit(struct drm_device *dev,
 		struct drm_atomic_state *state, bool nonblock)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_commit *c;
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *crtc_state;
 	struct drm_plane *plane;
 	struct drm_plane_state *old_plane_state, *new_plane_state;
 	int i, ret;

 	ret = drm_atomic_helper_prepare_planes(dev, state);
 	if (ret)
 		return ret;

 	c = commit_init(state);
 	if (!c) {
 		ret = -ENOMEM;
 		goto error;
 	}

 	/*
 	 * Figure out what crtcs we have:
 	 */
 	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
 		c->crtc_mask |= drm_crtc_mask(crtc);

 	/*
 	 * Figure out what fence to wait for:
 	 */
 	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
 		if ((new_plane_state->fb != old_plane_state->fb) && new_plane_state->fb) {
 			struct drm_gem_object *obj = msm_framebuffer_bo(new_plane_state->fb, 0);
 			struct msm_gem_object *msm_obj = to_msm_bo(obj);
 			struct dma_fence *fence = reservation_object_get_excl_rcu(msm_obj->resv);

 			drm_atomic_set_fence_for_plane(new_plane_state, fence);
 		}
 	}

 	/*
 	 * Wait for pending updates on any of the same crtc's and then
 	 * mark our set of crtc's as busy:
 	 */
 	ret = start_atomic(dev->dev_private, c->crtc_mask);
 	if (ret)
 		goto err_free;

 	BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);

 	/*
 	 * This is the point of no return - everything below never fails except
 	 * when the hw goes bonghits. Which means we can commit the new state on
 	 * the software side now.
 	 *
 	 * swap driver private state while still holding state_lock
 	 */
 	if (to_kms_state(state)->state)
 		priv->kms->funcs->swap_state(priv->kms, state);

 	/*
 	 * Everything below can be run asynchronously without the need to grab
 	 * any modeset locks at all under one conditions: It must be guaranteed
 	 * that the asynchronous work has either been cancelled (if the driver
 	 * supports it, which at least requires that the framebuffers get
 	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
 	 * before the new state gets committed on the software side with
 	 * drm_atomic_helper_swap_state().
 	 *
 	 * This scheme allows new atomic state updates to be prepared and
 	 * checked in parallel to the asynchronous completion of the previous
 	 * update. Which is important since compositors need to figure out the
 	 * composition of the next frame right after having submitted the
 	 * current layout.
 	 */

 	drm_atomic_state_get(state);
 	if (nonblock) {
 		queue_work(priv->atomic_wq, &c->work);
 		return 0;
 	}

 	complete_commit(c, false);

 	return 0;

 err_free:
 	kfree(c);
 error:
 	drm_atomic_helper_cleanup_planes(dev, state);
 	return ret;
 }

 struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev)
 {
 	struct msm_kms_state *state = kzalloc(sizeof(*state), GFP_KERNEL);

 	if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
 		kfree(state);
 		return NULL;
 	}

 	return &state->base;
 }

 void msm_atomic_state_clear(struct drm_atomic_state *s)
 {
 	struct msm_kms_state *state = to_kms_state(s);
 	drm_atomic_state_default_clear(&state->base);
 	kfree(state->state);
 	state->state = NULL;
 }

 void msm_atomic_state_free(struct drm_atomic_state *state)
 {
 	kfree(to_kms_state(state)->state);
 	drm_atomic_state_default_release(state);
 	kfree(state);
 }
	/*
	* Copyright (C) 2014 Red Hat
	* Author: Rob Clark <robdclark@gmail.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include "msm_drv.h"
	#include "msm_kms.h"
	#include "msm_gem.h"
	#include "msm_fence.h"

	struct msm_commit {
	struct drm_device *dev;
	struct drm_atomic_state *state;
	struct work_struct work;
	uint32_t crtc_mask;
	};

	static void commit_worker(struct work_struct *work);

	/* block until specified crtcs are no longer pending update, and
	* atomically mark them as pending update
	*/
	static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
	{
	int ret;

	spin_lock(&priv->pending_crtcs_event.lock);
	ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
	!(priv->pending_crtcs & crtc_mask));
	if (ret == 0) {
	DBG("start: %08x", crtc_mask);
	priv->pending_crtcs \|= crtc_mask;
	}
	spin_unlock(&priv->pending_crtcs_event.lock);

	return ret;
	}

	/* clear specified crtcs (no longer pending update)
	*/
	static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
	{
	spin_lock(&priv->pending_crtcs_event.lock);
	DBG("end: %08x", crtc_mask);
	priv->pending_crtcs &= ~crtc_mask;
	wake_up_all_locked(&priv->pending_crtcs_event);
	spin_unlock(&priv->pending_crtcs_event.lock);
	}

	static struct msm_commit commit_init(struct drm_atomic_state state)
	{
	struct msm_commit c = kzalloc(sizeof(c), GFP_KERNEL);

	if (!c)
	return NULL;

	c->dev = state->dev;
	c->state = state;

	INIT_WORK(&c->work, commit_worker);

	return c;
	}

	static void commit_destroy(struct msm_commit *c)
	{
	end_atomic(c->dev->dev_private, c->crtc_mask);
	kfree(c);
	}

	static void msm_atomic_wait_for_commit_done(struct drm_device *dev,
	struct drm_atomic_state *old_state)
	{
	struct drm_crtc *crtc;
	struct drm_crtc_state *new_crtc_state;
	struct msm_drm_private *priv = old_state->dev->dev_private;
	struct msm_kms *kms = priv->kms;
	int i;

	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
	if (!new_crtc_state->active)
	continue;

	if (drm_crtc_vblank_get(crtc))
	continue;

	kms->funcs->wait_for_crtc_commit_done(kms, crtc);

	drm_crtc_vblank_put(crtc);
	}
	}

	/* The (potentially) asynchronous part of the commit. At this point
	* nothing can fail short of armageddon.
	*/
	static void complete_commit(struct msm_commit *c, bool async)
	{
	struct drm_atomic_state *state = c->state;
	struct drm_device *dev = state->dev;
	struct msm_drm_private *priv = dev->dev_private;
	struct msm_kms *kms = priv->kms;

	drm_atomic_helper_wait_for_fences(dev, state, false);

	kms->funcs->prepare_commit(kms, state);

	drm_atomic_helper_commit_modeset_disables(dev, state);

	drm_atomic_helper_commit_planes(dev, state, 0);

	drm_atomic_helper_commit_modeset_enables(dev, state);

	/* NOTE: _wait_for_vblanks() only waits for vblank on
	* enabled CRTCs. So we end up faulting when disabling
	* due to (potentially) unref'ing the outgoing fb's
	* before the vblank when the disable has latched.
	*
	* But if it did wait on disabled (or newly disabled)
	* CRTCs, that would be racy (ie. we could have missed
	* the irq. We need some way to poll for pipe shut
	* down. Or just live with occasionally hitting the
	* timeout in the CRTC disable path (which really should
	* not be critical path)
	*/

	msm_atomic_wait_for_commit_done(dev, state);

	drm_atomic_helper_cleanup_planes(dev, state);

	kms->funcs->complete_commit(kms, state);

	drm_atomic_state_put(state);

	commit_destroy(c);
	}

	static void commit_worker(struct work_struct *work)
	{
	complete_commit(container_of(work, struct msm_commit, work), true);
	}

	/*
	* this func is identical to the drm_atomic_helper_check, but we keep this
	* because we might eventually need to have a more finegrained check
	* sequence without using the atomic helpers.
	*
	* In the past, we first called drm_atomic_helper_check_planes, and then
	* drm_atomic_helper_check_modeset. We needed this because the MDP5 plane's
	* ->atomic_check could update ->mode_changed for pixel format changes.
	* This, however isn't needed now because if there is a pixel format change,
	* we just assign a new hwpipe for it with a new SMP allocation. We might
	* eventually hit a condition where we would need to do a full modeset if
	* we run out of planes. There, we'd probably need to set mode_changed.
	*/
	int msm_atomic_check(struct drm_device *dev,
	struct drm_atomic_state *state)
	{
	int ret;

	ret = drm_atomic_helper_check_modeset(dev, state);
	if (ret)
	return ret;

	ret = drm_atomic_helper_check_planes(dev, state);
	if (ret)
	return ret;

	return ret;
	}

	/**
	* drm_atomic_helper_commit - commit validated state object
	* @dev: DRM device
	* @state: the driver state object
	* @nonblock: nonblocking commit
	*
	* This function commits a with drm_atomic_helper_check() pre-validated state
	* object. This can still fail when e.g. the framebuffer reservation fails.
	*
	* RETURNS
	* Zero for success or -errno.
	*/
	int msm_atomic_commit(struct drm_device *dev,
	struct drm_atomic_state *state, bool nonblock)
	{
	struct msm_drm_private *priv = dev->dev_private;
	struct msm_commit *c;
	struct drm_crtc *crtc;
	struct drm_crtc_state *crtc_state;
	struct drm_plane *plane;
	struct drm_plane_state old_plane_state, new_plane_state;
	int i, ret;

	ret = drm_atomic_helper_prepare_planes(dev, state);
	if (ret)
	return ret;

	c = commit_init(state);
	if (!c) {
	ret = -ENOMEM;
	goto error;
	}

	/*
	* Figure out what crtcs we have:
	*/
	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
	c->crtc_mask \|= drm_crtc_mask(crtc);

	/*
	* Figure out what fence to wait for:
	*/
	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
	if ((new_plane_state->fb != old_plane_state->fb) && new_plane_state->fb) {
	struct drm_gem_object *obj = msm_framebuffer_bo(new_plane_state->fb, 0);
	struct msm_gem_object *msm_obj = to_msm_bo(obj);
	struct dma_fence *fence = reservation_object_get_excl_rcu(msm_obj->resv);

	drm_atomic_set_fence_for_plane(new_plane_state, fence);
	}
	}

	/*
	* Wait for pending updates on any of the same crtc's and then
	* mark our set of crtc's as busy:
	*/
	ret = start_atomic(dev->dev_private, c->crtc_mask);
	if (ret)
	goto err_free;

	BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);

	/*
	* This is the point of no return - everything below never fails except
	* when the hw goes bonghits. Which means we can commit the new state on
	* the software side now.
	*
	* swap driver private state while still holding state_lock
	*/
	if (to_kms_state(state)->state)
	priv->kms->funcs->swap_state(priv->kms, state);

	/*
	* Everything below can be run asynchronously without the need to grab
	* any modeset locks at all under one conditions: It must be guaranteed
	* that the asynchronous work has either been cancelled (if the driver
	* supports it, which at least requires that the framebuffers get
	* cleaned up with drm_atomic_helper_cleanup_planes()) or completed
	* before the new state gets committed on the software side with
	* drm_atomic_helper_swap_state().
	*
	* This scheme allows new atomic state updates to be prepared and
	* checked in parallel to the asynchronous completion of the previous
	* update. Which is important since compositors need to figure out the
	* composition of the next frame right after having submitted the
	* current layout.
	*/

	drm_atomic_state_get(state);
	if (nonblock) {
	queue_work(priv->atomic_wq, &c->work);
	return 0;
	}

	complete_commit(c, false);

	return 0;

	err_free:
	kfree(c);
	error:
	drm_atomic_helper_cleanup_planes(dev, state);
	return ret;
	}

	struct drm_atomic_state msm_atomic_state_alloc(struct drm_device dev)
	{
	struct msm_kms_state state = kzalloc(sizeof(state), GFP_KERNEL);

	if (!state \|\| drm_atomic_state_init(dev, &state->base) < 0) {
	kfree(state);
	return NULL;
	}

	return &state->base;
	}

	void msm_atomic_state_clear(struct drm_atomic_state *s)
	{
	struct msm_kms_state *state = to_kms_state(s);
	drm_atomic_state_default_clear(&state->base);
	kfree(state->state);
	state->state = NULL;
	}

	void msm_atomic_state_free(struct drm_atomic_state *state)
	{
	kfree(to_kms_state(state)->state);
	drm_atomic_state_default_release(state);
	kfree(state);
	}