xref: /openbmc/linux/drivers/gpu/drm/msm/msm_atomic.c (revision e15a5365)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 Red Hat
4  * Author: Rob Clark <robdclark@gmail.com>
5  */
6 
7 #include <drm/drm_atomic_uapi.h>
8 #include <drm/drm_gem_framebuffer_helper.h>
9 #include <drm/drm_vblank.h>
10 
11 #include "msm_atomic_trace.h"
12 #include "msm_drv.h"
13 #include "msm_gem.h"
14 #include "msm_kms.h"
15 
16 int msm_atomic_prepare_fb(struct drm_plane *plane,
17 			  struct drm_plane_state *new_state)
18 {
19 	struct msm_drm_private *priv = plane->dev->dev_private;
20 	struct msm_kms *kms = priv->kms;
21 
22 	if (!new_state->fb)
23 		return 0;
24 
25 	drm_gem_fb_prepare_fb(plane, new_state);
26 
27 	return msm_framebuffer_prepare(new_state->fb, kms->aspace);
28 }
29 
30 /*
31  * Helpers to control vblanks while we flush.. basically just to ensure
32  * that vblank accounting is switched on, so we get valid seqn/timestamp
33  * on pageflip events (if requested)
34  */
35 
36 static void vblank_get(struct msm_kms *kms, unsigned crtc_mask)
37 {
38 	struct drm_crtc *crtc;
39 
40 	for_each_crtc_mask(kms->dev, crtc, crtc_mask) {
41 		if (!crtc->state->active)
42 			continue;
43 		drm_crtc_vblank_get(crtc);
44 	}
45 }
46 
47 static void vblank_put(struct msm_kms *kms, unsigned crtc_mask)
48 {
49 	struct drm_crtc *crtc;
50 
51 	for_each_crtc_mask(kms->dev, crtc, crtc_mask) {
52 		if (!crtc->state->active)
53 			continue;
54 		drm_crtc_vblank_put(crtc);
55 	}
56 }
57 
58 static void msm_atomic_async_commit(struct msm_kms *kms, int crtc_idx)
59 {
60 	unsigned crtc_mask = BIT(crtc_idx);
61 
62 	trace_msm_atomic_async_commit_start(crtc_mask);
63 
64 	mutex_lock(&kms->commit_lock);
65 
66 	if (!(kms->pending_crtc_mask & crtc_mask)) {
67 		mutex_unlock(&kms->commit_lock);
68 		goto out;
69 	}
70 
71 	kms->pending_crtc_mask &= ~crtc_mask;
72 
73 	kms->funcs->enable_commit(kms);
74 
75 	vblank_get(kms, crtc_mask);
76 
77 	/*
78 	 * Flush hardware updates:
79 	 */
80 	trace_msm_atomic_flush_commit(crtc_mask);
81 	kms->funcs->flush_commit(kms, crtc_mask);
82 	mutex_unlock(&kms->commit_lock);
83 
84 	/*
85 	 * Wait for flush to complete:
86 	 */
87 	trace_msm_atomic_wait_flush_start(crtc_mask);
88 	kms->funcs->wait_flush(kms, crtc_mask);
89 	trace_msm_atomic_wait_flush_finish(crtc_mask);
90 
91 	vblank_put(kms, crtc_mask);
92 
93 	mutex_lock(&kms->commit_lock);
94 	kms->funcs->complete_commit(kms, crtc_mask);
95 	mutex_unlock(&kms->commit_lock);
96 	kms->funcs->disable_commit(kms);
97 
98 out:
99 	trace_msm_atomic_async_commit_finish(crtc_mask);
100 }
101 
102 static enum hrtimer_restart msm_atomic_pending_timer(struct hrtimer *t)
103 {
104 	struct msm_pending_timer *timer = container_of(t,
105 			struct msm_pending_timer, timer);
106 	struct msm_drm_private *priv = timer->kms->dev->dev_private;
107 
108 	queue_work(priv->wq, &timer->work);
109 
110 	return HRTIMER_NORESTART;
111 }
112 
113 static void msm_atomic_pending_work(struct work_struct *work)
114 {
115 	struct msm_pending_timer *timer = container_of(work,
116 			struct msm_pending_timer, work);
117 
118 	msm_atomic_async_commit(timer->kms, timer->crtc_idx);
119 }
120 
121 void msm_atomic_init_pending_timer(struct msm_pending_timer *timer,
122 		struct msm_kms *kms, int crtc_idx)
123 {
124 	timer->kms = kms;
125 	timer->crtc_idx = crtc_idx;
126 	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
127 	timer->timer.function = msm_atomic_pending_timer;
128 	INIT_WORK(&timer->work, msm_atomic_pending_work);
129 }
130 
131 static bool can_do_async(struct drm_atomic_state *state,
132 		struct drm_crtc **async_crtc)
133 {
134 	struct drm_connector_state *connector_state;
135 	struct drm_connector *connector;
136 	struct drm_crtc_state *crtc_state;
137 	struct drm_crtc *crtc;
138 	int i, num_crtcs = 0;
139 
140 	if (!(state->legacy_cursor_update || state->async_update))
141 		return false;
142 
143 	/* any connector change, means slow path: */
144 	for_each_new_connector_in_state(state, connector, connector_state, i)
145 		return false;
146 
147 	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
148 		if (drm_atomic_crtc_needs_modeset(crtc_state))
149 			return false;
150 		if (++num_crtcs > 1)
151 			return false;
152 		*async_crtc = crtc;
153 	}
154 
155 	return true;
156 }
157 
158 /* Get bitmask of crtcs that will need to be flushed.  The bitmask
159  * can be used with for_each_crtc_mask() iterator, to iterate
160  * effected crtcs without needing to preserve the atomic state.
161  */
162 static unsigned get_crtc_mask(struct drm_atomic_state *state)
163 {
164 	struct drm_crtc_state *crtc_state;
165 	struct drm_crtc *crtc;
166 	unsigned i, mask = 0;
167 
168 	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
169 		mask |= drm_crtc_mask(crtc);
170 
171 	return mask;
172 }
173 
174 void msm_atomic_commit_tail(struct drm_atomic_state *state)
175 {
176 	struct drm_device *dev = state->dev;
177 	struct msm_drm_private *priv = dev->dev_private;
178 	struct msm_kms *kms = priv->kms;
179 	struct drm_crtc *async_crtc = NULL;
180 	unsigned crtc_mask = get_crtc_mask(state);
181 	bool async = kms->funcs->vsync_time &&
182 			can_do_async(state, &async_crtc);
183 
184 	trace_msm_atomic_commit_tail_start(async, crtc_mask);
185 
186 	kms->funcs->enable_commit(kms);
187 
188 	/*
189 	 * Ensure any previous (potentially async) commit has
190 	 * completed:
191 	 */
192 	trace_msm_atomic_wait_flush_start(crtc_mask);
193 	kms->funcs->wait_flush(kms, crtc_mask);
194 	trace_msm_atomic_wait_flush_finish(crtc_mask);
195 
196 	mutex_lock(&kms->commit_lock);
197 
198 	/*
199 	 * Now that there is no in-progress flush, prepare the
200 	 * current update:
201 	 */
202 	kms->funcs->prepare_commit(kms, state);
203 
204 	/*
205 	 * Push atomic updates down to hardware:
206 	 */
207 	drm_atomic_helper_commit_modeset_disables(dev, state);
208 	drm_atomic_helper_commit_planes(dev, state, 0);
209 	drm_atomic_helper_commit_modeset_enables(dev, state);
210 
211 	if (async) {
212 		struct msm_pending_timer *timer =
213 			&kms->pending_timers[drm_crtc_index(async_crtc)];
214 
215 		/* async updates are limited to single-crtc updates: */
216 		WARN_ON(crtc_mask != drm_crtc_mask(async_crtc));
217 
218 		/*
219 		 * Start timer if we don't already have an update pending
220 		 * on this crtc:
221 		 */
222 		if (!(kms->pending_crtc_mask & crtc_mask)) {
223 			ktime_t vsync_time, wakeup_time;
224 
225 			kms->pending_crtc_mask |= crtc_mask;
226 
227 			vsync_time = kms->funcs->vsync_time(kms, async_crtc);
228 			wakeup_time = ktime_sub(vsync_time, ms_to_ktime(1));
229 
230 			hrtimer_start(&timer->timer, wakeup_time,
231 					HRTIMER_MODE_ABS);
232 		}
233 
234 		kms->funcs->disable_commit(kms);
235 		mutex_unlock(&kms->commit_lock);
236 
237 		/*
238 		 * At this point, from drm core's perspective, we
239 		 * are done with the atomic update, so we can just
240 		 * go ahead and signal that it is done:
241 		 */
242 		drm_atomic_helper_commit_hw_done(state);
243 		drm_atomic_helper_cleanup_planes(dev, state);
244 
245 		trace_msm_atomic_commit_tail_finish(async, crtc_mask);
246 
247 		return;
248 	}
249 
250 	/*
251 	 * If there is any async flush pending on updated crtcs, fold
252 	 * them into the current flush.
253 	 */
254 	kms->pending_crtc_mask &= ~crtc_mask;
255 
256 	vblank_get(kms, crtc_mask);
257 
258 	/*
259 	 * Flush hardware updates:
260 	 */
261 	trace_msm_atomic_flush_commit(crtc_mask);
262 	kms->funcs->flush_commit(kms, crtc_mask);
263 	mutex_unlock(&kms->commit_lock);
264 
265 	/*
266 	 * Wait for flush to complete:
267 	 */
268 	trace_msm_atomic_wait_flush_start(crtc_mask);
269 	kms->funcs->wait_flush(kms, crtc_mask);
270 	trace_msm_atomic_wait_flush_finish(crtc_mask);
271 
272 	vblank_put(kms, crtc_mask);
273 
274 	mutex_lock(&kms->commit_lock);
275 	kms->funcs->complete_commit(kms, crtc_mask);
276 	mutex_unlock(&kms->commit_lock);
277 	kms->funcs->disable_commit(kms);
278 
279 	drm_atomic_helper_commit_hw_done(state);
280 	drm_atomic_helper_cleanup_planes(dev, state);
281 
282 	trace_msm_atomic_commit_tail_finish(async, crtc_mask);
283 }
284