1/*
  2 * Copyright (C) 2014 Red Hat
  3 * Author: Rob Clark <robdclark@gmail.com>
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under the terms of the GNU General Public License version 2 as published by
  7 * the Free Software Foundation.
  8 *
  9 * This program is distributed in the hope that it will be useful, but WITHOUT
 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 12 * more details.
 13 *
 14 * You should have received a copy of the GNU General Public License along with
 15 * this program.  If not, see <http://www.gnu.org/licenses/>.
 16 */
 17
 18#include "msm_drv.h"
 19#include "msm_kms.h"
 20#include "msm_gem.h"
 21#include "msm_fence.h"
 22
 23struct msm_commit {
 24	struct drm_device *dev;
 25	struct drm_atomic_state *state;
 26	struct work_struct work;
 27	uint32_t crtc_mask;
 28};
 29
 30static void commit_worker(struct work_struct *work);
 31
 32/* block until specified crtcs are no longer pending update, and
 33 * atomically mark them as pending update
 34 */
 35static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
 36{
 37	int ret;
 38
 39	spin_lock(&priv->pending_crtcs_event.lock);
 40	ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
 41			!(priv->pending_crtcs & crtc_mask));
 42	if (ret == 0) {
 43		DBG("start: %08x", crtc_mask);
 44		priv->pending_crtcs |= crtc_mask;
 45	}
 46	spin_unlock(&priv->pending_crtcs_event.lock);
 47
 48	return ret;
 49}
 50
 51/* clear specified crtcs (no longer pending update)
 52 */
 53static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
 54{
 55	spin_lock(&priv->pending_crtcs_event.lock);
 56	DBG("end: %08x", crtc_mask);
 57	priv->pending_crtcs &= ~crtc_mask;
 58	wake_up_all_locked(&priv->pending_crtcs_event);
 59	spin_unlock(&priv->pending_crtcs_event.lock);
 60}
 61
 62static struct msm_commit *commit_init(struct drm_atomic_state *state)
 63{
 64	struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
 65
 66	if (!c)
 67		return NULL;
 68
 69	c->dev = state->dev;
 70	c->state = state;
 71
 72	INIT_WORK(&c->work, commit_worker);
 73
 74	return c;
 75}
 76
 77static void commit_destroy(struct msm_commit *c)
 78{
 79	end_atomic(c->dev->dev_private, c->crtc_mask);
 80	kfree(c);
 81}
 82
 83static void msm_atomic_wait_for_commit_done(struct drm_device *dev,
 84		struct drm_atomic_state *old_state)
 85{
 86	struct drm_crtc *crtc;
 87	struct drm_crtc_state *new_crtc_state;
 88	struct msm_drm_private *priv = old_state->dev->dev_private;
 89	struct msm_kms *kms = priv->kms;
 90	int i;
 91
 92	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
 93		if (!new_crtc_state->active)
 94			continue;
 95
 96		kms->funcs->wait_for_crtc_commit_done(kms, crtc);
 97	}
 98}
 99
100/* The (potentially) asynchronous part of the commit.  At this point
101 * nothing can fail short of armageddon.
102 */
103static void complete_commit(struct msm_commit *c, bool async)
104{
105	struct drm_atomic_state *state = c->state;
106	struct drm_device *dev = state->dev;
107	struct msm_drm_private *priv = dev->dev_private;
108	struct msm_kms *kms = priv->kms;
109
110	drm_atomic_helper_wait_for_fences(dev, state, false);
111
112	kms->funcs->prepare_commit(kms, state);
113
114	drm_atomic_helper_commit_modeset_disables(dev, state);
115
116	drm_atomic_helper_commit_planes(dev, state, 0);
117
118	drm_atomic_helper_commit_modeset_enables(dev, state);
119
120	/* NOTE: _wait_for_vblanks() only waits for vblank on
121	 * enabled CRTCs.  So we end up faulting when disabling
122	 * due to (potentially) unref'ing the outgoing fb's
123	 * before the vblank when the disable has latched.
124	 *
125	 * But if it did wait on disabled (or newly disabled)
126	 * CRTCs, that would be racy (ie. we could have missed
127	 * the irq.  We need some way to poll for pipe shut
128	 * down.  Or just live with occasionally hitting the
129	 * timeout in the CRTC disable path (which really should
130	 * not be critical path)
131	 */
132
133	msm_atomic_wait_for_commit_done(dev, state);
134
135	drm_atomic_helper_cleanup_planes(dev, state);
136
137	kms->funcs->complete_commit(kms, state);
138
139	drm_atomic_state_put(state);
140
141	commit_destroy(c);
142}
143
144static void commit_worker(struct work_struct *work)
145{
146	complete_commit(container_of(work, struct msm_commit, work), true);
147}
148
149/**
150 * drm_atomic_helper_commit - commit validated state object
151 * @dev: DRM device
152 * @state: the driver state object
153 * @nonblock: nonblocking commit
154 *
155 * This function commits a with drm_atomic_helper_check() pre-validated state
156 * object. This can still fail when e.g. the framebuffer reservation fails.
157 *
158 * RETURNS
159 * Zero for success or -errno.
160 */
161int msm_atomic_commit(struct drm_device *dev,
162		struct drm_atomic_state *state, bool nonblock)
163{
164	struct msm_drm_private *priv = dev->dev_private;
165	struct msm_commit *c;
166	struct drm_crtc *crtc;
167	struct drm_crtc_state *crtc_state;
168	struct drm_plane *plane;
169	struct drm_plane_state *old_plane_state, *new_plane_state;
170	int i, ret;
171
172	ret = drm_atomic_helper_prepare_planes(dev, state);
173	if (ret)
174		return ret;
175
176	/*
177	 * Note that plane->atomic_async_check() should fail if we need
178	 * to re-assign hwpipe or anything that touches global atomic
179	 * state, so we'll never go down the async update path in those
180	 * cases.
181	 */
182	if (state->async_update) {
183		drm_atomic_helper_async_commit(dev, state);
184		drm_atomic_helper_cleanup_planes(dev, state);
185		return 0;
186	}
187
188	c = commit_init(state);
189	if (!c) {
190		ret = -ENOMEM;
191		goto error;
192	}
193
194	/*
195	 * Figure out what crtcs we have:
196	 */
197	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
198		c->crtc_mask |= drm_crtc_mask(crtc);
199
200	/*
201	 * Figure out what fence to wait for:
202	 */
203	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
204		if ((new_plane_state->fb != old_plane_state->fb) && new_plane_state->fb) {
205			struct drm_gem_object *obj = msm_framebuffer_bo(new_plane_state->fb, 0);
206			struct msm_gem_object *msm_obj = to_msm_bo(obj);
207			struct dma_fence *fence = reservation_object_get_excl_rcu(msm_obj->resv);
208
209			drm_atomic_set_fence_for_plane(new_plane_state, fence);
210		}
211	}
212
213	/*
214	 * Wait for pending updates on any of the same crtc's and then
215	 * mark our set of crtc's as busy:
216	 */
217	ret = start_atomic(dev->dev_private, c->crtc_mask);
218	if (ret)
219		goto err_free;
220
221	BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
222
223	/*
224	 * This is the point of no return - everything below never fails except
225	 * when the hw goes bonghits. Which means we can commit the new state on
226	 * the software side now.
227	 *
228	 * swap driver private state while still holding state_lock
229	 */
230	if (to_kms_state(state)->state)
231		priv->kms->funcs->swap_state(priv->kms, state);
232
233	/*
234	 * Everything below can be run asynchronously without the need to grab
235	 * any modeset locks at all under one conditions: It must be guaranteed
236	 * that the asynchronous work has either been cancelled (if the driver
237	 * supports it, which at least requires that the framebuffers get
238	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
239	 * before the new state gets committed on the software side with
240	 * drm_atomic_helper_swap_state().
241	 *
242	 * This scheme allows new atomic state updates to be prepared and
243	 * checked in parallel to the asynchronous completion of the previous
244	 * update. Which is important since compositors need to figure out the
245	 * composition of the next frame right after having submitted the
246	 * current layout.
247	 */
248
249	drm_atomic_state_get(state);
250	if (nonblock) {
251		queue_work(priv->atomic_wq, &c->work);
252		return 0;
253	}
254
255	complete_commit(c, false);
256
257	return 0;
258
259err_free:
260	kfree(c);
261error:
262	drm_atomic_helper_cleanup_planes(dev, state);
263	return ret;
264}
265
266struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev)
267{
268	struct msm_kms_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
269
270	if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
271		kfree(state);
272		return NULL;
273	}
274
275	return &state->base;
276}
277
278void msm_atomic_state_clear(struct drm_atomic_state *s)
279{
280	struct msm_kms_state *state = to_kms_state(s);
281	drm_atomic_state_default_clear(&state->base);
282	kfree(state->state);
283	state->state = NULL;
284}
285
286void msm_atomic_state_free(struct drm_atomic_state *state)
287{
288	kfree(to_kms_state(state)->state);
289	drm_atomic_state_default_release(state);
290	kfree(state);
291}