xref: /openbmc/linux/drivers/gpu/drm/msm/msm_atomic.c (revision 7eab0b9d)
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 void msm_atomic_pending_work(struct kthread_work *work)
120 {
121 	struct msm_pending_timer *timer = container_of(work,
122 			struct msm_pending_timer, work.work);
123 
124 	msm_atomic_async_commit(timer->kms, timer->crtc_idx);
125 }
126 
127 int msm_atomic_init_pending_timer(struct msm_pending_timer *timer,
128 		struct msm_kms *kms, int crtc_idx)
129 {
130 	timer->kms = kms;
131 	timer->crtc_idx = crtc_idx;
132 
133 	timer->worker = kthread_create_worker(0, "atomic-worker-%d", crtc_idx);
134 	if (IS_ERR(timer->worker)) {
135 		int ret = PTR_ERR(timer->worker);
136 		timer->worker = NULL;
137 		return ret;
138 	}
139 	sched_set_fifo(timer->worker->task);
140 
141 	msm_hrtimer_work_init(&timer->work, timer->worker,
142 			      msm_atomic_pending_work,
143 			      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
144 
145 	return 0;
146 }
147 
148 void msm_atomic_destroy_pending_timer(struct msm_pending_timer *timer)
149 {
150 	if (timer->worker)
151 		kthread_destroy_worker(timer->worker);
152 }
153 
154 static bool can_do_async(struct drm_atomic_state *state,
155 		struct drm_crtc **async_crtc)
156 {
157 	struct drm_connector_state *connector_state;
158 	struct drm_connector *connector;
159 	struct drm_crtc_state *crtc_state;
160 	struct drm_crtc *crtc;
161 	int i, num_crtcs = 0;
162 
163 	if (!(state->legacy_cursor_update || state->async_update))
164 		return false;
165 
166 	/* any connector change, means slow path: */
167 	for_each_new_connector_in_state(state, connector, connector_state, i)
168 		return false;
169 
170 	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
171 		if (drm_atomic_crtc_needs_modeset(crtc_state))
172 			return false;
173 		if (++num_crtcs > 1)
174 			return false;
175 		*async_crtc = crtc;
176 	}
177 
178 	return true;
179 }
180 
181 /* Get bitmask of crtcs that will need to be flushed.  The bitmask
182  * can be used with for_each_crtc_mask() iterator, to iterate
183  * effected crtcs without needing to preserve the atomic state.
184  */
185 static unsigned get_crtc_mask(struct drm_atomic_state *state)
186 {
187 	struct drm_crtc_state *crtc_state;
188 	struct drm_crtc *crtc;
189 	unsigned i, mask = 0;
190 
191 	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
192 		mask |= drm_crtc_mask(crtc);
193 
194 	return mask;
195 }
196 
197 void msm_atomic_commit_tail(struct drm_atomic_state *state)
198 {
199 	struct drm_device *dev = state->dev;
200 	struct msm_drm_private *priv = dev->dev_private;
201 	struct msm_kms *kms = priv->kms;
202 	struct drm_crtc *async_crtc = NULL;
203 	unsigned crtc_mask = get_crtc_mask(state);
204 	bool async = kms->funcs->vsync_time &&
205 			can_do_async(state, &async_crtc);
206 
207 	trace_msm_atomic_commit_tail_start(async, crtc_mask);
208 
209 	kms->funcs->enable_commit(kms);
210 
211 	/*
212 	 * Ensure any previous (potentially async) commit has
213 	 * completed:
214 	 */
215 	lock_crtcs(kms, crtc_mask);
216 	trace_msm_atomic_wait_flush_start(crtc_mask);
217 	kms->funcs->wait_flush(kms, crtc_mask);
218 	trace_msm_atomic_wait_flush_finish(crtc_mask);
219 
220 	/*
221 	 * Now that there is no in-progress flush, prepare the
222 	 * current update:
223 	 */
224 	kms->funcs->prepare_commit(kms, state);
225 
226 	/*
227 	 * Push atomic updates down to hardware:
228 	 */
229 	drm_atomic_helper_commit_modeset_disables(dev, state);
230 	drm_atomic_helper_commit_planes(dev, state, 0);
231 	drm_atomic_helper_commit_modeset_enables(dev, state);
232 
233 	if (async) {
234 		struct msm_pending_timer *timer =
235 			&kms->pending_timers[drm_crtc_index(async_crtc)];
236 
237 		/* async updates are limited to single-crtc updates: */
238 		WARN_ON(crtc_mask != drm_crtc_mask(async_crtc));
239 
240 		/*
241 		 * Start timer if we don't already have an update pending
242 		 * on this crtc:
243 		 */
244 		if (!(kms->pending_crtc_mask & crtc_mask)) {
245 			ktime_t vsync_time, wakeup_time;
246 
247 			kms->pending_crtc_mask |= crtc_mask;
248 
249 			vsync_time = kms->funcs->vsync_time(kms, async_crtc);
250 			wakeup_time = ktime_sub(vsync_time, ms_to_ktime(1));
251 
252 			msm_hrtimer_queue_work(&timer->work, wakeup_time,
253 					HRTIMER_MODE_ABS);
254 		}
255 
256 		kms->funcs->disable_commit(kms);
257 		unlock_crtcs(kms, crtc_mask);
258 		/*
259 		 * At this point, from drm core's perspective, we
260 		 * are done with the atomic update, so we can just
261 		 * go ahead and signal that it is done:
262 		 */
263 		drm_atomic_helper_commit_hw_done(state);
264 		drm_atomic_helper_cleanup_planes(dev, state);
265 
266 		trace_msm_atomic_commit_tail_finish(async, crtc_mask);
267 
268 		return;
269 	}
270 
271 	/*
272 	 * If there is any async flush pending on updated crtcs, fold
273 	 * them into the current flush.
274 	 */
275 	kms->pending_crtc_mask &= ~crtc_mask;
276 
277 	vblank_get(kms, crtc_mask);
278 
279 	/*
280 	 * Flush hardware updates:
281 	 */
282 	trace_msm_atomic_flush_commit(crtc_mask);
283 	kms->funcs->flush_commit(kms, crtc_mask);
284 	unlock_crtcs(kms, crtc_mask);
285 	/*
286 	 * Wait for flush to complete:
287 	 */
288 	trace_msm_atomic_wait_flush_start(crtc_mask);
289 	kms->funcs->wait_flush(kms, crtc_mask);
290 	trace_msm_atomic_wait_flush_finish(crtc_mask);
291 
292 	vblank_put(kms, crtc_mask);
293 
294 	lock_crtcs(kms, crtc_mask);
295 	kms->funcs->complete_commit(kms, crtc_mask);
296 	unlock_crtcs(kms, crtc_mask);
297 	kms->funcs->disable_commit(kms);
298 
299 	drm_atomic_helper_commit_hw_done(state);
300 	drm_atomic_helper_cleanup_planes(dev, state);
301 
302 	trace_msm_atomic_commit_tail_finish(async, crtc_mask);
303 }
304