xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_crtc.c (revision 9a6b55ac)
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 bool vkms_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
80 			       int *max_error, ktime_t *vblank_time,
81 			       bool in_vblank_irq)
82 {
83 	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
84 	struct vkms_output *output = &vkmsdev->output;
85 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
86 
87 	*vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
88 
89 	if (WARN_ON(*vblank_time == vblank->time))
90 		return true;
91 
92 	/*
93 	 * To prevent races we roll the hrtimer forward before we do any
94 	 * interrupt processing - this is how real hw works (the interrupt is
95 	 * only generated after all the vblank registers are updated) and what
96 	 * the vblank core expects. Therefore we need to always correct the
97 	 * timestampe by one frame.
98 	 */
99 	*vblank_time -= output->period_ns;
100 
101 	return true;
102 }
103 
104 static struct drm_crtc_state *
105 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
106 {
107 	struct vkms_crtc_state *vkms_state;
108 
109 	if (WARN_ON(!crtc->state))
110 		return NULL;
111 
112 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
113 	if (!vkms_state)
114 		return NULL;
115 
116 	__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
117 
118 	INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
119 
120 	return &vkms_state->base;
121 }
122 
123 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
124 					   struct drm_crtc_state *state)
125 {
126 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
127 
128 	__drm_atomic_helper_crtc_destroy_state(state);
129 
130 	WARN_ON(work_pending(&vkms_state->composer_work));
131 	kfree(vkms_state->active_planes);
132 	kfree(vkms_state);
133 }
134 
135 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
136 {
137 	struct vkms_crtc_state *vkms_state =
138 		kzalloc(sizeof(*vkms_state), GFP_KERNEL);
139 
140 	if (crtc->state)
141 		vkms_atomic_crtc_destroy_state(crtc, crtc->state);
142 
143 	__drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
144 	if (vkms_state)
145 		INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
146 }
147 
148 static const struct drm_crtc_funcs vkms_crtc_funcs = {
149 	.set_config             = drm_atomic_helper_set_config,
150 	.destroy                = drm_crtc_cleanup,
151 	.page_flip              = drm_atomic_helper_page_flip,
152 	.reset                  = vkms_atomic_crtc_reset,
153 	.atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
154 	.atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
155 	.enable_vblank		= vkms_enable_vblank,
156 	.disable_vblank		= vkms_disable_vblank,
157 	.get_crc_sources	= vkms_get_crc_sources,
158 	.set_crc_source		= vkms_set_crc_source,
159 	.verify_crc_source	= vkms_verify_crc_source,
160 };
161 
162 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
163 				  struct drm_crtc_state *state)
164 {
165 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
166 	struct drm_plane *plane;
167 	struct drm_plane_state *plane_state;
168 	int i = 0, ret;
169 
170 	if (vkms_state->active_planes)
171 		return 0;
172 
173 	ret = drm_atomic_add_affected_planes(state->state, crtc);
174 	if (ret < 0)
175 		return ret;
176 
177 	drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
178 		plane_state = drm_atomic_get_existing_plane_state(state->state,
179 								  plane);
180 		WARN_ON(!plane_state);
181 
182 		if (!plane_state->visible)
183 			continue;
184 
185 		i++;
186 	}
187 
188 	vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
189 	if (!vkms_state->active_planes)
190 		return -ENOMEM;
191 	vkms_state->num_active_planes = i;
192 
193 	i = 0;
194 	drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
195 		plane_state = drm_atomic_get_existing_plane_state(state->state,
196 								  plane);
197 
198 		if (!plane_state->visible)
199 			continue;
200 
201 		vkms_state->active_planes[i++] =
202 			to_vkms_plane_state(plane_state);
203 	}
204 
205 	return 0;
206 }
207 
208 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
209 				    struct drm_crtc_state *old_state)
210 {
211 	drm_crtc_vblank_on(crtc);
212 }
213 
214 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
215 				     struct drm_crtc_state *old_state)
216 {
217 	drm_crtc_vblank_off(crtc);
218 }
219 
220 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
221 				   struct drm_crtc_state *old_crtc_state)
222 {
223 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
224 
225 	/* This lock is held across the atomic commit to block vblank timer
226 	 * from scheduling vkms_composer_worker until the composer is updated
227 	 */
228 	spin_lock_irq(&vkms_output->lock);
229 }
230 
231 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
232 				   struct drm_crtc_state *old_crtc_state)
233 {
234 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
235 
236 	if (crtc->state->event) {
237 		spin_lock(&crtc->dev->event_lock);
238 
239 		if (drm_crtc_vblank_get(crtc) != 0)
240 			drm_crtc_send_vblank_event(crtc, crtc->state->event);
241 		else
242 			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
243 
244 		spin_unlock(&crtc->dev->event_lock);
245 
246 		crtc->state->event = NULL;
247 	}
248 
249 	vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
250 
251 	spin_unlock_irq(&vkms_output->lock);
252 }
253 
254 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
255 	.atomic_check	= vkms_crtc_atomic_check,
256 	.atomic_begin	= vkms_crtc_atomic_begin,
257 	.atomic_flush	= vkms_crtc_atomic_flush,
258 	.atomic_enable	= vkms_crtc_atomic_enable,
259 	.atomic_disable	= vkms_crtc_atomic_disable,
260 };
261 
262 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
263 		   struct drm_plane *primary, struct drm_plane *cursor)
264 {
265 	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
266 	int ret;
267 
268 	ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
269 					&vkms_crtc_funcs, NULL);
270 	if (ret) {
271 		DRM_ERROR("Failed to init CRTC\n");
272 		return ret;
273 	}
274 
275 	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
276 
277 	spin_lock_init(&vkms_out->lock);
278 	spin_lock_init(&vkms_out->composer_lock);
279 
280 	vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
281 	if (!vkms_out->composer_workq)
282 		return -ENOMEM;
283 
284 	return ret;
285 }
286