1// SPDX-License-Identifier: GPL-2.0+
  2
  3#include <linux/dma-fence.h>
  4
  5#include <drm/drm_atomic.h>
  6#include <drm/drm_atomic_helper.h>
  7#include <drm/drm_probe_helper.h>
  8#include <drm/drm_vblank.h>
  9
 10#include "vkms_drv.h"
 11
 12static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
 13{
 14	struct vkms_output *output = container_of(timer, struct vkms_output,
 15						  vblank_hrtimer);
 16	struct drm_crtc *crtc = &output->crtc;
 17	struct vkms_crtc_state *state;
 18	u64 ret_overrun;
 19	bool ret, fence_cookie;
 20
 21	fence_cookie = dma_fence_begin_signalling();
 22
 23	ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
 24					  output->period_ns);
 25	if (ret_overrun != 1)
 26		pr_warn("%s: vblank timer overrun\n", __func__);
 27
 28	spin_lock(&output->lock);
 29	ret = drm_crtc_handle_vblank(crtc);
 30	if (!ret)
 31		DRM_ERROR("vkms failure on handling vblank");
 32
 33	state = output->composer_state;
 34	spin_unlock(&output->lock);
 35
 36	if (state && output->composer_enabled) {
 37		u64 frame = drm_crtc_accurate_vblank_count(crtc);
 38
 39		/* update frame_start only if a queued vkms_composer_worker()
 40		 * has read the data
 41		 */
 42		spin_lock(&output->composer_lock);
 43		if (!state->crc_pending)
 44			state->frame_start = frame;
 45		else
 46			DRM_DEBUG_DRIVER("crc worker falling behind, frame_start: %llu, frame_end: %llu\n",
 47					 state->frame_start, frame);
 48		state->frame_end = frame;
 49		state->crc_pending = true;
 50		spin_unlock(&output->composer_lock);
 51
 52		ret = queue_work(output->composer_workq, &state->composer_work);
 53		if (!ret)
 54			DRM_DEBUG_DRIVER("Composer worker already queued\n");
 55	}
 56
 57	dma_fence_end_signalling(fence_cookie);
 58
 59	return HRTIMER_RESTART;
 60}
 61
 62static int vkms_enable_vblank(struct drm_crtc *crtc)
 63{
 64	struct drm_device *dev = crtc->dev;
 65	unsigned int pipe = drm_crtc_index(crtc);
 66	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
 67	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
 68
 69	drm_calc_timestamping_constants(crtc, &crtc->mode);
 70
 71	hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 72	out->vblank_hrtimer.function = &vkms_vblank_simulate;
 73	out->period_ns = ktime_set(0, vblank->framedur_ns);
 74	hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
 75
 76	return 0;
 77}
 78
 79static void vkms_disable_vblank(struct drm_crtc *crtc)
 80{
 81	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
 82
 83	hrtimer_cancel(&out->vblank_hrtimer);
 84}
 85
 86static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
 87				      int *max_error, ktime_t *vblank_time,
 88				      bool in_vblank_irq)
 89{
 90	struct drm_device *dev = crtc->dev;
 91	unsigned int pipe = crtc->index;
 92	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
 93	struct vkms_output *output = &vkmsdev->output;
 94	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
 95
 96	if (!READ_ONCE(vblank->enabled)) {
 97		*vblank_time = ktime_get();
 98		return true;
 99	}
100
101	*vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
102
103	if (WARN_ON(*vblank_time == vblank->time))
104		return true;
105
106	/*
107	 * To prevent races we roll the hrtimer forward before we do any
108	 * interrupt processing - this is how real hw works (the interrupt is
109	 * only generated after all the vblank registers are updated) and what
110	 * the vblank core expects. Therefore we need to always correct the
111	 * timestampe by one frame.
112	 */
113	*vblank_time -= output->period_ns;
114
115	return true;
116}
117
118static struct drm_crtc_state *
119vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
120{
121	struct vkms_crtc_state *vkms_state;
122
123	if (WARN_ON(!crtc->state))
124		return NULL;
125
126	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
127	if (!vkms_state)
128		return NULL;
129
130	__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
131
132	INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
133
134	return &vkms_state->base;
135}
136
137static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
138					   struct drm_crtc_state *state)
139{
140	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
141
142	__drm_atomic_helper_crtc_destroy_state(state);
143
144	WARN_ON(work_pending(&vkms_state->composer_work));
145	kfree(vkms_state->active_planes);
146	kfree(vkms_state);
147}
148
149static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
150{
151	struct vkms_crtc_state *vkms_state =
152		kzalloc(sizeof(*vkms_state), GFP_KERNEL);
153
154	if (crtc->state)
155		vkms_atomic_crtc_destroy_state(crtc, crtc->state);
156
157	__drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
158	if (vkms_state)
159		INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
160}
161
162static const struct drm_crtc_funcs vkms_crtc_funcs = {
163	.set_config             = drm_atomic_helper_set_config,
164	.page_flip              = drm_atomic_helper_page_flip,
165	.reset                  = vkms_atomic_crtc_reset,
166	.atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
167	.atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
168	.enable_vblank		= vkms_enable_vblank,
169	.disable_vblank		= vkms_disable_vblank,
170	.get_vblank_timestamp	= vkms_get_vblank_timestamp,
171	.get_crc_sources	= vkms_get_crc_sources,
172	.set_crc_source		= vkms_set_crc_source,
173	.verify_crc_source	= vkms_verify_crc_source,
174};
175
176static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
177				  struct drm_atomic_state *state)
178{
179	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
180									  crtc);
181	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(crtc_state);
182	struct drm_plane *plane;
183	struct drm_plane_state *plane_state;
184	int i = 0, ret;
185
186	if (vkms_state->active_planes)
187		return 0;
188
189	ret = drm_atomic_add_affected_planes(crtc_state->state, crtc);
190	if (ret < 0)
191		return ret;
192
193	drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
194		plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
195								  plane);
196		WARN_ON(!plane_state);
197
198		if (!plane_state->visible)
199			continue;
200
201		i++;
202	}
203
204	vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
205	if (!vkms_state->active_planes)
206		return -ENOMEM;
207	vkms_state->num_active_planes = i;
208
209	i = 0;
210	drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
211		plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
212								  plane);
213
214		if (!plane_state->visible)
215			continue;
216
217		vkms_state->active_planes[i++] =
218			to_vkms_plane_state(plane_state);
219	}
220
221	return 0;
222}
223
224static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
225				    struct drm_atomic_state *state)
226{
227	drm_crtc_vblank_on(crtc);
228}
229
230static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
231				     struct drm_atomic_state *state)
232{
233	drm_crtc_vblank_off(crtc);
234}
235
236static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
237				   struct drm_atomic_state *state)
238{
239	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
240
241	/* This lock is held across the atomic commit to block vblank timer
242	 * from scheduling vkms_composer_worker until the composer is updated
243	 */
244	spin_lock_irq(&vkms_output->lock);
245}
246
247static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
248				   struct drm_atomic_state *state)
249{
250	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
251
252	if (crtc->state->event) {
253		spin_lock(&crtc->dev->event_lock);
254
255		if (drm_crtc_vblank_get(crtc) != 0)
256			drm_crtc_send_vblank_event(crtc, crtc->state->event);
257		else
258			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
259
260		spin_unlock(&crtc->dev->event_lock);
261
262		crtc->state->event = NULL;
263	}
264
265	vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
266
267	spin_unlock_irq(&vkms_output->lock);
268}
269
270static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
271	.atomic_check	= vkms_crtc_atomic_check,
272	.atomic_begin	= vkms_crtc_atomic_begin,
273	.atomic_flush	= vkms_crtc_atomic_flush,
274	.atomic_enable	= vkms_crtc_atomic_enable,
275	.atomic_disable	= vkms_crtc_atomic_disable,
276};
277
278int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
279		   struct drm_plane *primary, struct drm_plane *cursor)
280{
281	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
282	int ret;
283
284	ret = drmm_crtc_init_with_planes(dev, crtc, primary, cursor,
285					 &vkms_crtc_funcs, NULL);
286	if (ret) {
287		DRM_ERROR("Failed to init CRTC\n");
288		return ret;
289	}
290
291	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
292
293	drm_mode_crtc_set_gamma_size(crtc, VKMS_LUT_SIZE);
294	drm_crtc_enable_color_mgmt(crtc, 0, false, VKMS_LUT_SIZE);
295
296	spin_lock_init(&vkms_out->lock);
297	spin_lock_init(&vkms_out->composer_lock);
298
299	vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
300	if (!vkms_out->composer_workq)
301		return -ENOMEM;
302
303	return ret;
304}