xref: /openbmc/linux/drivers/gpu/drm/msm/msm_atomic.c (revision 3d37ef41)
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_atomic_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_plane_helper_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 lock_crtcs(struct msm_kms *kms, unsigned int crtc_mask)
59 {
60 	int crtc_index;
61 	struct drm_crtc *crtc;
62 
63 	for_each_crtc_mask(kms->dev, crtc, crtc_mask) {
64 		crtc_index = drm_crtc_index(crtc);
65 		mutex_lock_nested(&kms->commit_lock[crtc_index], crtc_index);
66 	}
67 }
68 
69 static void unlock_crtcs(struct msm_kms *kms, unsigned int crtc_mask)
70 {
71 	struct drm_crtc *crtc;
72 
73 	for_each_crtc_mask_reverse(kms->dev, crtc, crtc_mask)
74 		mutex_unlock(&kms->commit_lock[drm_crtc_index(crtc)]);
75 }
76 
77 static void msm_atomic_async_commit(struct msm_kms *kms, int crtc_idx)
78 {
79 	unsigned crtc_mask = BIT(crtc_idx);
80 
81 	trace_msm_atomic_async_commit_start(crtc_mask);
82 
83 	lock_crtcs(kms, crtc_mask);
84 
85 	if (!(kms->pending_crtc_mask & crtc_mask)) {
86 		unlock_crtcs(kms, crtc_mask);
87 		goto out;
88 	}
89 
90 	kms->pending_crtc_mask &= ~crtc_mask;
91 
92 	kms->funcs->enable_commit(kms);
93 
94 	vblank_get(kms, crtc_mask);
95 
96 	/*
97 	 * Flush hardware updates:
98 	 */
99 	trace_msm_atomic_flush_commit(crtc_mask);
100 	kms->funcs->flush_commit(kms, crtc_mask);
101 
102 	/*
103 	 * Wait for flush to complete:
104 	 */
105 	trace_msm_atomic_wait_flush_start(crtc_mask);
106 	kms->funcs->wait_flush(kms, crtc_mask);
107 	trace_msm_atomic_wait_flush_finish(crtc_mask);
108 
109 	vblank_put(kms, crtc_mask);
110 
111 	kms->funcs->complete_commit(kms, crtc_mask);
112 	unlock_crtcs(kms, crtc_mask);
113 	kms->funcs->disable_commit(kms);
114 
115 out:
116 	trace_msm_atomic_async_commit_finish(crtc_mask);
117 }
118 
119 static enum hrtimer_restart msm_atomic_pending_timer(struct hrtimer *t)
120 {
121 	struct msm_pending_timer *timer = container_of(t,
122 			struct msm_pending_timer, timer);
123 
124 	kthread_queue_work(timer->worker, &timer->work);
125 
126 	return HRTIMER_NORESTART;
127 }
128 
129 static void msm_atomic_pending_work(struct kthread_work *work)
130 {
131 	struct msm_pending_timer *timer = container_of(work,
132 			struct msm_pending_timer, work);
133 
134 	msm_atomic_async_commit(timer->kms, timer->crtc_idx);
135 }
136 
137 int msm_atomic_init_pending_timer(struct msm_pending_timer *timer,
138 		struct msm_kms *kms, int crtc_idx)
139 {
140 	timer->kms = kms;
141 	timer->crtc_idx = crtc_idx;
142 	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
143 	timer->timer.function = msm_atomic_pending_timer;
144 
145 	timer->worker = kthread_create_worker(0, "atomic-worker-%d", crtc_idx);
146 	if (IS_ERR(timer->worker)) {
147 		int ret = PTR_ERR(timer->worker);
148 		timer->worker = NULL;
149 		return ret;
150 	}
151 	sched_set_fifo(timer->worker->task);
152 	kthread_init_work(&timer->work, msm_atomic_pending_work);
153 
154 	return 0;
155 }
156 
157 void msm_atomic_destroy_pending_timer(struct msm_pending_timer *timer)
158 {
159 	if (timer->worker)
160 		kthread_destroy_worker(timer->worker);
161 }
162 
163 static bool can_do_async(struct drm_atomic_state *state,
164 		struct drm_crtc **async_crtc)
165 {
166 	struct drm_connector_state *connector_state;
167 	struct drm_connector *connector;
168 	struct drm_crtc_state *crtc_state;
169 	struct drm_crtc *crtc;
170 	int i, num_crtcs = 0;
171 
172 	if (!(state->legacy_cursor_update || state->async_update))
173 		return false;
174 
175 	/* any connector change, means slow path: */
176 	for_each_new_connector_in_state(state, connector, connector_state, i)
177 		return false;
178 
179 	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
180 		if (drm_atomic_crtc_needs_modeset(crtc_state))
181 			return false;
182 		if (++num_crtcs > 1)
183 			return false;
184 		*async_crtc = crtc;
185 	}
186 
187 	return true;
188 }
189 
190 /* Get bitmask of crtcs that will need to be flushed.  The bitmask
191  * can be used with for_each_crtc_mask() iterator, to iterate
192  * effected crtcs without needing to preserve the atomic state.
193  */
194 static unsigned get_crtc_mask(struct drm_atomic_state *state)
195 {
196 	struct drm_crtc_state *crtc_state;
197 	struct drm_crtc *crtc;
198 	unsigned i, mask = 0;
199 
200 	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
201 		mask |= drm_crtc_mask(crtc);
202 
203 	return mask;
204 }
205 
206 void msm_atomic_commit_tail(struct drm_atomic_state *state)
207 {
208 	struct drm_device *dev = state->dev;
209 	struct msm_drm_private *priv = dev->dev_private;
210 	struct msm_kms *kms = priv->kms;
211 	struct drm_crtc *async_crtc = NULL;
212 	unsigned crtc_mask = get_crtc_mask(state);
213 	bool async = kms->funcs->vsync_time &&
214 			can_do_async(state, &async_crtc);
215 
216 	trace_msm_atomic_commit_tail_start(async, crtc_mask);
217 
218 	kms->funcs->enable_commit(kms);
219 
220 	/*
221 	 * Ensure any previous (potentially async) commit has
222 	 * completed:
223 	 */
224 	lock_crtcs(kms, crtc_mask);
225 	trace_msm_atomic_wait_flush_start(crtc_mask);
226 	kms->funcs->wait_flush(kms, crtc_mask);
227 	trace_msm_atomic_wait_flush_finish(crtc_mask);
228 
229 	/*
230 	 * Now that there is no in-progress flush, prepare the
231 	 * current update:
232 	 */
233 	kms->funcs->prepare_commit(kms, state);
234 
235 	/*
236 	 * Push atomic updates down to hardware:
237 	 */
238 	drm_atomic_helper_commit_modeset_disables(dev, state);
239 	drm_atomic_helper_commit_planes(dev, state, 0);
240 	drm_atomic_helper_commit_modeset_enables(dev, state);
241 
242 	if (async) {
243 		struct msm_pending_timer *timer =
244 			&kms->pending_timers[drm_crtc_index(async_crtc)];
245 
246 		/* async updates are limited to single-crtc updates: */
247 		WARN_ON(crtc_mask != drm_crtc_mask(async_crtc));
248 
249 		/*
250 		 * Start timer if we don't already have an update pending
251 		 * on this crtc:
252 		 */
253 		if (!(kms->pending_crtc_mask & crtc_mask)) {
254 			ktime_t vsync_time, wakeup_time;
255 
256 			kms->pending_crtc_mask |= crtc_mask;
257 
258 			vsync_time = kms->funcs->vsync_time(kms, async_crtc);
259 			wakeup_time = ktime_sub(vsync_time, ms_to_ktime(1));
260 
261 			hrtimer_start(&timer->timer, wakeup_time,
262 					HRTIMER_MODE_ABS);
263 		}
264 
265 		kms->funcs->disable_commit(kms);
266 		unlock_crtcs(kms, crtc_mask);
267 		/*
268 		 * At this point, from drm core's perspective, we
269 		 * are done with the atomic update, so we can just
270 		 * go ahead and signal that it is done:
271 		 */
272 		drm_atomic_helper_commit_hw_done(state);
273 		drm_atomic_helper_cleanup_planes(dev, state);
274 
275 		trace_msm_atomic_commit_tail_finish(async, crtc_mask);
276 
277 		return;
278 	}
279 
280 	/*
281 	 * If there is any async flush pending on updated crtcs, fold
282 	 * them into the current flush.
283 	 */
284 	kms->pending_crtc_mask &= ~crtc_mask;
285 
286 	vblank_get(kms, crtc_mask);
287 
288 	/*
289 	 * Flush hardware updates:
290 	 */
291 	trace_msm_atomic_flush_commit(crtc_mask);
292 	kms->funcs->flush_commit(kms, crtc_mask);
293 	unlock_crtcs(kms, crtc_mask);
294 	/*
295 	 * Wait for flush to complete:
296 	 */
297 	trace_msm_atomic_wait_flush_start(crtc_mask);
298 	kms->funcs->wait_flush(kms, crtc_mask);
299 	trace_msm_atomic_wait_flush_finish(crtc_mask);
300 
301 	vblank_put(kms, crtc_mask);
302 
303 	lock_crtcs(kms, crtc_mask);
304 	kms->funcs->complete_commit(kms, crtc_mask);
305 	unlock_crtcs(kms, crtc_mask);
306 	kms->funcs->disable_commit(kms);
307 
308 	drm_atomic_helper_commit_hw_done(state);
309 	drm_atomic_helper_cleanup_planes(dev, state);
310 
311 	trace_msm_atomic_commit_tail_finish(async, crtc_mask);
312 }
313