xref: /openbmc/linux/drivers/gpu/drm/msm/msm_atomic.c (revision dbdc671d)
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 lock_crtcs(struct msm_kms *kms, unsigned int crtc_mask)
59 {
60 	struct drm_crtc *crtc;
61 
62 	for_each_crtc_mask(kms->dev, crtc, crtc_mask)
63 		mutex_lock(&kms->commit_lock[drm_crtc_index(crtc)]);
64 }
65 
66 static void unlock_crtcs(struct msm_kms *kms, unsigned int crtc_mask)
67 {
68 	struct drm_crtc *crtc;
69 
70 	for_each_crtc_mask_reverse(kms->dev, crtc, crtc_mask)
71 		mutex_unlock(&kms->commit_lock[drm_crtc_index(crtc)]);
72 }
73 
74 static void msm_atomic_async_commit(struct msm_kms *kms, int crtc_idx)
75 {
76 	unsigned crtc_mask = BIT(crtc_idx);
77 
78 	trace_msm_atomic_async_commit_start(crtc_mask);
79 
80 	lock_crtcs(kms, crtc_mask);
81 
82 	if (!(kms->pending_crtc_mask & crtc_mask)) {
83 		unlock_crtcs(kms, crtc_mask);
84 		goto out;
85 	}
86 
87 	kms->pending_crtc_mask &= ~crtc_mask;
88 
89 	kms->funcs->enable_commit(kms);
90 
91 	vblank_get(kms, crtc_mask);
92 
93 	/*
94 	 * Flush hardware updates:
95 	 */
96 	trace_msm_atomic_flush_commit(crtc_mask);
97 	kms->funcs->flush_commit(kms, crtc_mask);
98 
99 	/*
100 	 * Wait for flush to complete:
101 	 */
102 	trace_msm_atomic_wait_flush_start(crtc_mask);
103 	kms->funcs->wait_flush(kms, crtc_mask);
104 	trace_msm_atomic_wait_flush_finish(crtc_mask);
105 
106 	vblank_put(kms, crtc_mask);
107 
108 	kms->funcs->complete_commit(kms, crtc_mask);
109 	unlock_crtcs(kms, crtc_mask);
110 	kms->funcs->disable_commit(kms);
111 
112 out:
113 	trace_msm_atomic_async_commit_finish(crtc_mask);
114 }
115 
116 static enum hrtimer_restart msm_atomic_pending_timer(struct hrtimer *t)
117 {
118 	struct msm_pending_timer *timer = container_of(t,
119 			struct msm_pending_timer, timer);
120 
121 	kthread_queue_work(timer->worker, &timer->work);
122 
123 	return HRTIMER_NORESTART;
124 }
125 
126 static void msm_atomic_pending_work(struct kthread_work *work)
127 {
128 	struct msm_pending_timer *timer = container_of(work,
129 			struct msm_pending_timer, work);
130 
131 	msm_atomic_async_commit(timer->kms, timer->crtc_idx);
132 }
133 
134 int msm_atomic_init_pending_timer(struct msm_pending_timer *timer,
135 		struct msm_kms *kms, int crtc_idx)
136 {
137 	timer->kms = kms;
138 	timer->crtc_idx = crtc_idx;
139 	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
140 	timer->timer.function = msm_atomic_pending_timer;
141 
142 	timer->worker = kthread_create_worker(0, "atomic-worker-%d", crtc_idx);
143 	if (IS_ERR(timer->worker)) {
144 		int ret = PTR_ERR(timer->worker);
145 		timer->worker = NULL;
146 		return ret;
147 	}
148 	sched_set_fifo(timer->worker->task);
149 	kthread_init_work(&timer->work, msm_atomic_pending_work);
150 
151 	return 0;
152 }
153 
154 void msm_atomic_destroy_pending_timer(struct msm_pending_timer *timer)
155 {
156 	if (timer->worker)
157 		kthread_destroy_worker(timer->worker);
158 }
159 
160 static bool can_do_async(struct drm_atomic_state *state,
161 		struct drm_crtc **async_crtc)
162 {
163 	struct drm_connector_state *connector_state;
164 	struct drm_connector *connector;
165 	struct drm_crtc_state *crtc_state;
166 	struct drm_crtc *crtc;
167 	int i, num_crtcs = 0;
168 
169 	if (!(state->legacy_cursor_update || state->async_update))
170 		return false;
171 
172 	/* any connector change, means slow path: */
173 	for_each_new_connector_in_state(state, connector, connector_state, i)
174 		return false;
175 
176 	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
177 		if (drm_atomic_crtc_needs_modeset(crtc_state))
178 			return false;
179 		if (++num_crtcs > 1)
180 			return false;
181 		*async_crtc = crtc;
182 	}
183 
184 	return true;
185 }
186 
187 /* Get bitmask of crtcs that will need to be flushed.  The bitmask
188  * can be used with for_each_crtc_mask() iterator, to iterate
189  * effected crtcs without needing to preserve the atomic state.
190  */
191 static unsigned get_crtc_mask(struct drm_atomic_state *state)
192 {
193 	struct drm_crtc_state *crtc_state;
194 	struct drm_crtc *crtc;
195 	unsigned i, mask = 0;
196 
197 	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
198 		mask |= drm_crtc_mask(crtc);
199 
200 	return mask;
201 }
202 
203 void msm_atomic_commit_tail(struct drm_atomic_state *state)
204 {
205 	struct drm_device *dev = state->dev;
206 	struct msm_drm_private *priv = dev->dev_private;
207 	struct msm_kms *kms = priv->kms;
208 	struct drm_crtc *async_crtc = NULL;
209 	unsigned crtc_mask = get_crtc_mask(state);
210 	bool async = kms->funcs->vsync_time &&
211 			can_do_async(state, &async_crtc);
212 
213 	trace_msm_atomic_commit_tail_start(async, crtc_mask);
214 
215 	kms->funcs->enable_commit(kms);
216 
217 	/*
218 	 * Ensure any previous (potentially async) commit has
219 	 * completed:
220 	 */
221 	lock_crtcs(kms, crtc_mask);
222 	trace_msm_atomic_wait_flush_start(crtc_mask);
223 	kms->funcs->wait_flush(kms, crtc_mask);
224 	trace_msm_atomic_wait_flush_finish(crtc_mask);
225 
226 	/*
227 	 * Now that there is no in-progress flush, prepare the
228 	 * current update:
229 	 */
230 	kms->funcs->prepare_commit(kms, state);
231 
232 	/*
233 	 * Push atomic updates down to hardware:
234 	 */
235 	drm_atomic_helper_commit_modeset_disables(dev, state);
236 	drm_atomic_helper_commit_planes(dev, state, 0);
237 	drm_atomic_helper_commit_modeset_enables(dev, state);
238 
239 	if (async) {
240 		struct msm_pending_timer *timer =
241 			&kms->pending_timers[drm_crtc_index(async_crtc)];
242 
243 		/* async updates are limited to single-crtc updates: */
244 		WARN_ON(crtc_mask != drm_crtc_mask(async_crtc));
245 
246 		/*
247 		 * Start timer if we don't already have an update pending
248 		 * on this crtc:
249 		 */
250 		if (!(kms->pending_crtc_mask & crtc_mask)) {
251 			ktime_t vsync_time, wakeup_time;
252 
253 			kms->pending_crtc_mask |= crtc_mask;
254 
255 			vsync_time = kms->funcs->vsync_time(kms, async_crtc);
256 			wakeup_time = ktime_sub(vsync_time, ms_to_ktime(1));
257 
258 			hrtimer_start(&timer->timer, wakeup_time,
259 					HRTIMER_MODE_ABS);
260 		}
261 
262 		kms->funcs->disable_commit(kms);
263 		unlock_crtcs(kms, crtc_mask);
264 		/*
265 		 * At this point, from drm core's perspective, we
266 		 * are done with the atomic update, so we can just
267 		 * go ahead and signal that it is done:
268 		 */
269 		drm_atomic_helper_commit_hw_done(state);
270 		drm_atomic_helper_cleanup_planes(dev, state);
271 
272 		trace_msm_atomic_commit_tail_finish(async, crtc_mask);
273 
274 		return;
275 	}
276 
277 	/*
278 	 * If there is any async flush pending on updated crtcs, fold
279 	 * them into the current flush.
280 	 */
281 	kms->pending_crtc_mask &= ~crtc_mask;
282 
283 	vblank_get(kms, crtc_mask);
284 
285 	/*
286 	 * Flush hardware updates:
287 	 */
288 	trace_msm_atomic_flush_commit(crtc_mask);
289 	kms->funcs->flush_commit(kms, crtc_mask);
290 	unlock_crtcs(kms, crtc_mask);
291 	/*
292 	 * Wait for flush to complete:
293 	 */
294 	trace_msm_atomic_wait_flush_start(crtc_mask);
295 	kms->funcs->wait_flush(kms, crtc_mask);
296 	trace_msm_atomic_wait_flush_finish(crtc_mask);
297 
298 	vblank_put(kms, crtc_mask);
299 
300 	lock_crtcs(kms, crtc_mask);
301 	kms->funcs->complete_commit(kms, crtc_mask);
302 	unlock_crtcs(kms, crtc_mask);
303 	kms->funcs->disable_commit(kms);
304 
305 	drm_atomic_helper_commit_hw_done(state);
306 	drm_atomic_helper_cleanup_planes(dev, state);
307 
308 	trace_msm_atomic_commit_tail_finish(async, crtc_mask);
309 }
310