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
 10static 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
 55static 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
 72static 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
 79static 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
106static struct drm_crtc_state *
107vkms_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
125static 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
137static 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
150static 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
165static 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
211static 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
217static 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
223static 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
234static 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
257static 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
265int 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}