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}
305