xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_crtc.c (revision de3a9980)
1 // SPDX-License-Identifier: GPL-2.0+
2 
3 #include <drm/drm_atomic.h>
4 #include <drm/drm_atomic_helper.h>
5 #include <drm/drm_probe_helper.h>
6 #include <drm/drm_vblank.h>
7 
8 #include "vkms_drv.h"
9 
10 static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
11 {
12 	struct vkms_output *output = container_of(timer, struct vkms_output,
13 						  vblank_hrtimer);
14 	struct drm_crtc *crtc = &output->crtc;
15 	struct vkms_crtc_state *state;
16 	u64 ret_overrun;
17 	bool ret;
18 
19 	ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
20 					  output->period_ns);
21 	WARN_ON(ret_overrun != 1);
22 
23 	spin_lock(&output->lock);
24 	ret = drm_crtc_handle_vblank(crtc);
25 	if (!ret)
26 		DRM_ERROR("vkms failure on handling vblank");
27 
28 	state = output->composer_state;
29 	spin_unlock(&output->lock);
30 
31 	if (state && output->composer_enabled) {
32 		u64 frame = drm_crtc_accurate_vblank_count(crtc);
33 
34 		/* update frame_start only if a queued vkms_composer_worker()
35 		 * has read the data
36 		 */
37 		spin_lock(&output->composer_lock);
38 		if (!state->crc_pending)
39 			state->frame_start = frame;
40 		else
41 			DRM_DEBUG_DRIVER("crc worker falling behind, frame_start: %llu, frame_end: %llu\n",
42 					 state->frame_start, frame);
43 		state->frame_end = frame;
44 		state->crc_pending = true;
45 		spin_unlock(&output->composer_lock);
46 
47 		ret = queue_work(output->composer_workq, &state->composer_work);
48 		if (!ret)
49 			DRM_DEBUG_DRIVER("Composer worker already queued\n");
50 	}
51 
52 	return HRTIMER_RESTART;
53 }
54 
55 static int vkms_enable_vblank(struct drm_crtc *crtc)
56 {
57 	struct drm_device *dev = crtc->dev;
58 	unsigned int pipe = drm_crtc_index(crtc);
59 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
60 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
61 
62 	drm_calc_timestamping_constants(crtc, &crtc->mode);
63 
64 	hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
65 	out->vblank_hrtimer.function = &vkms_vblank_simulate;
66 	out->period_ns = ktime_set(0, vblank->framedur_ns);
67 	hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
68 
69 	return 0;
70 }
71 
72 static void vkms_disable_vblank(struct drm_crtc *crtc)
73 {
74 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
75 
76 	hrtimer_cancel(&out->vblank_hrtimer);
77 }
78 
79 static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
80 				      int *max_error, ktime_t *vblank_time,
81 				      bool in_vblank_irq)
82 {
83 	struct drm_device *dev = crtc->dev;
84 	unsigned int pipe = crtc->index;
85 	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
86 	struct vkms_output *output = &vkmsdev->output;
87 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
88 
89 	if (!READ_ONCE(vblank->enabled)) {
90 		*vblank_time = ktime_get();
91 		return true;
92 	}
93 
94 	*vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
95 
96 	if (WARN_ON(*vblank_time == vblank->time))
97 		return true;
98 
99 	/*
100 	 * To prevent races we roll the hrtimer forward before we do any
101 	 * interrupt processing - this is how real hw works (the interrupt is
102 	 * only generated after all the vblank registers are updated) and what
103 	 * the vblank core expects. Therefore we need to always correct the
104 	 * timestampe by one frame.
105 	 */
106 	*vblank_time -= output->period_ns;
107 
108 	return true;
109 }
110 
111 static struct drm_crtc_state *
112 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
113 {
114 	struct vkms_crtc_state *vkms_state;
115 
116 	if (WARN_ON(!crtc->state))
117 		return NULL;
118 
119 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
120 	if (!vkms_state)
121 		return NULL;
122 
123 	__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
124 
125 	INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
126 
127 	return &vkms_state->base;
128 }
129 
130 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
131 					   struct drm_crtc_state *state)
132 {
133 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
134 
135 	__drm_atomic_helper_crtc_destroy_state(state);
136 
137 	WARN_ON(work_pending(&vkms_state->composer_work));
138 	kfree(vkms_state->active_planes);
139 	kfree(vkms_state);
140 }
141 
142 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
143 {
144 	struct vkms_crtc_state *vkms_state =
145 		kzalloc(sizeof(*vkms_state), GFP_KERNEL);
146 
147 	if (crtc->state)
148 		vkms_atomic_crtc_destroy_state(crtc, crtc->state);
149 
150 	__drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
151 	if (vkms_state)
152 		INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
153 }
154 
155 static const struct drm_crtc_funcs vkms_crtc_funcs = {
156 	.set_config             = drm_atomic_helper_set_config,
157 	.destroy                = drm_crtc_cleanup,
158 	.page_flip              = drm_atomic_helper_page_flip,
159 	.reset                  = vkms_atomic_crtc_reset,
160 	.atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
161 	.atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
162 	.enable_vblank		= vkms_enable_vblank,
163 	.disable_vblank		= vkms_disable_vblank,
164 	.get_vblank_timestamp	= vkms_get_vblank_timestamp,
165 	.get_crc_sources	= vkms_get_crc_sources,
166 	.set_crc_source		= vkms_set_crc_source,
167 	.verify_crc_source	= vkms_verify_crc_source,
168 };
169 
170 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
171 				  struct drm_atomic_state *state)
172 {
173 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
174 									  crtc);
175 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(crtc_state);
176 	struct drm_plane *plane;
177 	struct drm_plane_state *plane_state;
178 	int i = 0, ret;
179 
180 	if (vkms_state->active_planes)
181 		return 0;
182 
183 	ret = drm_atomic_add_affected_planes(crtc_state->state, crtc);
184 	if (ret < 0)
185 		return ret;
186 
187 	drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
188 		plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
189 								  plane);
190 		WARN_ON(!plane_state);
191 
192 		if (!plane_state->visible)
193 			continue;
194 
195 		i++;
196 	}
197 
198 	vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
199 	if (!vkms_state->active_planes)
200 		return -ENOMEM;
201 	vkms_state->num_active_planes = i;
202 
203 	i = 0;
204 	drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
205 		plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
206 								  plane);
207 
208 		if (!plane_state->visible)
209 			continue;
210 
211 		vkms_state->active_planes[i++] =
212 			to_vkms_plane_state(plane_state);
213 	}
214 
215 	return 0;
216 }
217 
218 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
219 				    struct drm_atomic_state *state)
220 {
221 	drm_crtc_vblank_on(crtc);
222 }
223 
224 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
225 				     struct drm_atomic_state *state)
226 {
227 	drm_crtc_vblank_off(crtc);
228 }
229 
230 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
231 				   struct drm_atomic_state *state)
232 {
233 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
234 
235 	/* This lock is held across the atomic commit to block vblank timer
236 	 * from scheduling vkms_composer_worker until the composer is updated
237 	 */
238 	spin_lock_irq(&vkms_output->lock);
239 }
240 
241 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
242 				   struct drm_atomic_state *state)
243 {
244 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
245 
246 	if (crtc->state->event) {
247 		spin_lock(&crtc->dev->event_lock);
248 
249 		if (drm_crtc_vblank_get(crtc) != 0)
250 			drm_crtc_send_vblank_event(crtc, crtc->state->event);
251 		else
252 			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
253 
254 		spin_unlock(&crtc->dev->event_lock);
255 
256 		crtc->state->event = NULL;
257 	}
258 
259 	vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
260 
261 	spin_unlock_irq(&vkms_output->lock);
262 }
263 
264 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
265 	.atomic_check	= vkms_crtc_atomic_check,
266 	.atomic_begin	= vkms_crtc_atomic_begin,
267 	.atomic_flush	= vkms_crtc_atomic_flush,
268 	.atomic_enable	= vkms_crtc_atomic_enable,
269 	.atomic_disable	= vkms_crtc_atomic_disable,
270 };
271 
272 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
273 		   struct drm_plane *primary, struct drm_plane *cursor)
274 {
275 	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
276 	int ret;
277 
278 	ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
279 					&vkms_crtc_funcs, NULL);
280 	if (ret) {
281 		DRM_ERROR("Failed to init CRTC\n");
282 		return ret;
283 	}
284 
285 	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
286 
287 	spin_lock_init(&vkms_out->lock);
288 	spin_lock_init(&vkms_out->composer_lock);
289 
290 	vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
291 	if (!vkms_out->composer_workq)
292 		return -ENOMEM;
293 
294 	return ret;
295 }
296