summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/msm/msm_atomic.c
blob: 18fd643b6e6915c3a2e13c149640d9917459eb12 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 * 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"

struct msm_commit {
	struct drm_device *dev;
	struct drm_atomic_state *state;
	uint32_t fence;
	struct msm_fence_cb fence_cb;
	uint32_t crtc_mask;
};

static void fence_cb(struct msm_fence_cb *cb);

/* 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;

	/* TODO we might need a way to indicate to run the cb on a
	 * different wq so wait_for_vblanks() doesn't block retiring
	 * bo's..
	 */
	INIT_FENCE_CB(&c->fence_cb, fence_cb);

	return c;
}

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

/* The (potentially) asynchronous part of the commit.  At this point
 * nothing can fail short of armageddon.
 */
static void complete_commit(struct msm_commit *c)
{
	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;

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

	drm_atomic_helper_commit_pre_planes(dev, state);

	drm_atomic_helper_commit_planes(dev, state);

	drm_atomic_helper_commit_post_planes(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)
	 */

	drm_atomic_helper_wait_for_vblanks(dev, state);

	drm_atomic_helper_cleanup_planes(dev, state);

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

	drm_atomic_state_free(state);

	commit_destroy(c);
}

static void fence_cb(struct msm_fence_cb *cb)
{
	struct msm_commit *c =
			container_of(cb, struct msm_commit, fence_cb);
	complete_commit(c);
}

static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
{
	struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0);
	c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ));
}


int msm_atomic_check(struct drm_device *dev,
		     struct drm_atomic_state *state)
{
	int ret;

	/*
	 * msm ->atomic_check can update ->mode_changed for pixel format
	 * changes, hence must be run before we check the modeset changes.
	 */
	ret = drm_atomic_helper_check_planes(dev, state);
	if (ret)
		return ret;

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

	return ret;
}

/**
 * drm_atomic_helper_commit - commit validated state object
 * @dev: DRM device
 * @state: the driver state object
 * @async: asynchronous 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. For
 * now this doesn't implement asynchronous commits.
 *
 * RETURNS
 * Zero for success or -errno.
 */
int msm_atomic_commit(struct drm_device *dev,
		struct drm_atomic_state *state, bool async)
{
	int nplanes = dev->mode_config.num_total_plane;
	int ncrtcs = dev->mode_config.num_crtc;
	struct timespec timeout;
	struct msm_commit *c;
	int i, ret;

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

	c = commit_init(state);
	if (!c)
		return -ENOMEM;

	/*
	 * Figure out what crtcs we have:
	 */
	for (i = 0; i < ncrtcs; i++) {
		struct drm_crtc *crtc = state->crtcs[i];
		if (!crtc)
			continue;
		c->crtc_mask |= (1 << drm_crtc_index(crtc));
	}

	/*
	 * Figure out what fence to wait for:
	 */
	for (i = 0; i < nplanes; i++) {
		struct drm_plane *plane = state->planes[i];
		struct drm_plane_state *new_state = state->plane_states[i];

		if (!plane)
			continue;

		if ((plane->state->fb != new_state->fb) && new_state->fb)
			add_fb(c, new_state->fb);
	}

	/*
	 * 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) {
		kfree(c);
		return ret;
	}

	/*
	 * 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.
	 */

	drm_atomic_helper_swap_state(dev, 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.
	 */

	if (async) {
		msm_queue_fence_cb(dev, &c->fence_cb, c->fence);
		return 0;
	}

	jiffies_to_timespec(jiffies + msecs_to_jiffies(1000), &timeout);

	ret = msm_wait_fence_interruptable(dev, c->fence, &timeout);
	if (ret) {
		WARN_ON(ret);  // TODO unswap state back?  or??
		commit_destroy(c);
		return ret;
	}

	complete_commit(c);

	return 0;
}
OpenPOWER on IntegriCloud