xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_crtc.c (revision 15e3ae36)
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 	*vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
90 
91 	if (WARN_ON(*vblank_time == vblank->time))
92 		return true;
93 
94 	/*
95 	 * To prevent races we roll the hrtimer forward before we do any
96 	 * interrupt processing - this is how real hw works (the interrupt is
97 	 * only generated after all the vblank registers are updated) and what
98 	 * the vblank core expects. Therefore we need to always correct the
99 	 * timestampe by one frame.
100 	 */
101 	*vblank_time -= output->period_ns;
102 
103 	return true;
104 }
105 
106 static struct drm_crtc_state *
107 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
108 {
109 	struct vkms_crtc_state *vkms_state;
110 
111 	if (WARN_ON(!crtc->state))
112 		return NULL;
113 
114 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
115 	if (!vkms_state)
116 		return NULL;
117 
118 	__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
119 
120 	INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
121 
122 	return &vkms_state->base;
123 }
124 
125 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
126 					   struct drm_crtc_state *state)
127 {
128 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
129 
130 	__drm_atomic_helper_crtc_destroy_state(state);
131 
132 	WARN_ON(work_pending(&vkms_state->composer_work));
133 	kfree(vkms_state->active_planes);
134 	kfree(vkms_state);
135 }
136 
137 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
138 {
139 	struct vkms_crtc_state *vkms_state =
140 		kzalloc(sizeof(*vkms_state), GFP_KERNEL);
141 
142 	if (crtc->state)
143 		vkms_atomic_crtc_destroy_state(crtc, crtc->state);
144 
145 	__drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
146 	if (vkms_state)
147 		INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
148 }
149 
150 static const struct drm_crtc_funcs vkms_crtc_funcs = {
151 	.set_config             = drm_atomic_helper_set_config,
152 	.destroy                = drm_crtc_cleanup,
153 	.page_flip              = drm_atomic_helper_page_flip,
154 	.reset                  = vkms_atomic_crtc_reset,
155 	.atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
156 	.atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
157 	.enable_vblank		= vkms_enable_vblank,
158 	.disable_vblank		= vkms_disable_vblank,
159 	.get_vblank_timestamp	= vkms_get_vblank_timestamp,
160 	.get_crc_sources	= vkms_get_crc_sources,
161 	.set_crc_source		= vkms_set_crc_source,
162 	.verify_crc_source	= vkms_verify_crc_source,
163 };
164 
165 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
166 				  struct drm_crtc_state *state)
167 {
168 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
169 	struct drm_plane *plane;
170 	struct drm_plane_state *plane_state;
171 	int i = 0, ret;
172 
173 	if (vkms_state->active_planes)
174 		return 0;
175 
176 	ret = drm_atomic_add_affected_planes(state->state, crtc);
177 	if (ret < 0)
178 		return ret;
179 
180 	drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
181 		plane_state = drm_atomic_get_existing_plane_state(state->state,
182 								  plane);
183 		WARN_ON(!plane_state);
184 
185 		if (!plane_state->visible)
186 			continue;
187 
188 		i++;
189 	}
190 
191 	vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
192 	if (!vkms_state->active_planes)
193 		return -ENOMEM;
194 	vkms_state->num_active_planes = i;
195 
196 	i = 0;
197 	drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
198 		plane_state = drm_atomic_get_existing_plane_state(state->state,
199 								  plane);
200 
201 		if (!plane_state->visible)
202 			continue;
203 
204 		vkms_state->active_planes[i++] =
205 			to_vkms_plane_state(plane_state);
206 	}
207 
208 	return 0;
209 }
210 
211 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
212 				    struct drm_crtc_state *old_state)
213 {
214 	drm_crtc_vblank_on(crtc);
215 }
216 
217 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
218 				     struct drm_crtc_state *old_state)
219 {
220 	drm_crtc_vblank_off(crtc);
221 }
222 
223 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
224 				   struct drm_crtc_state *old_crtc_state)
225 {
226 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
227 
228 	/* This lock is held across the atomic commit to block vblank timer
229 	 * from scheduling vkms_composer_worker until the composer is updated
230 	 */
231 	spin_lock_irq(&vkms_output->lock);
232 }
233 
234 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
235 				   struct drm_crtc_state *old_crtc_state)
236 {
237 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
238 
239 	if (crtc->state->event) {
240 		spin_lock(&crtc->dev->event_lock);
241 
242 		if (drm_crtc_vblank_get(crtc) != 0)
243 			drm_crtc_send_vblank_event(crtc, crtc->state->event);
244 		else
245 			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
246 
247 		spin_unlock(&crtc->dev->event_lock);
248 
249 		crtc->state->event = NULL;
250 	}
251 
252 	vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
253 
254 	spin_unlock_irq(&vkms_output->lock);
255 }
256 
257 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
258 	.atomic_check	= vkms_crtc_atomic_check,
259 	.atomic_begin	= vkms_crtc_atomic_begin,
260 	.atomic_flush	= vkms_crtc_atomic_flush,
261 	.atomic_enable	= vkms_crtc_atomic_enable,
262 	.atomic_disable	= vkms_crtc_atomic_disable,
263 };
264 
265 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
266 		   struct drm_plane *primary, struct drm_plane *cursor)
267 {
268 	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
269 	int ret;
270 
271 	ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
272 					&vkms_crtc_funcs, NULL);
273 	if (ret) {
274 		DRM_ERROR("Failed to init CRTC\n");
275 		return ret;
276 	}
277 
278 	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
279 
280 	spin_lock_init(&vkms_out->lock);
281 	spin_lock_init(&vkms_out->composer_lock);
282 
283 	vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
284 	if (!vkms_out->composer_workq)
285 		return -ENOMEM;
286 
287 	return ret;
288 }
289