summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/vc4/vc4_kms.c
blob: be8dd8262f2794866e12655f6b4fda70e6b8b8cd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/*
 * Copyright (C) 2015 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/**
 * DOC: VC4 KMS
 *
 * This is the general code for implementing KMS mode setting that
 * doesn't clearly associate with any of the other objects (plane,
 * crtc, HDMI encoder).
 */

#include "drm_crtc.h"
#include "drm_atomic.h"
#include "drm_atomic_helper.h"
#include "drm_crtc_helper.h"
#include "drm_plane_helper.h"
#include "drm_fb_cma_helper.h"
#include "vc4_drv.h"

static void vc4_output_poll_changed(struct drm_device *dev)
{
	struct vc4_dev *vc4 = to_vc4_dev(dev);

	drm_fbdev_cma_hotplug_event(vc4->fbdev);
}

struct vc4_commit {
	struct drm_device *dev;
	struct drm_atomic_state *state;
	struct vc4_seqno_cb cb;
};

static void
vc4_atomic_complete_commit(struct vc4_commit *c)
{
	struct drm_atomic_state *state = c->state;
	struct drm_device *dev = state->dev;
	struct vc4_dev *vc4 = to_vc4_dev(dev);

	drm_atomic_helper_commit_modeset_disables(dev, state);

	drm_atomic_helper_commit_planes(dev, state, 0);

	drm_atomic_helper_commit_modeset_enables(dev, state);

	/* Make sure that drm_atomic_helper_wait_for_vblanks()
	 * actually waits for vblank.  If we're doing a full atomic
	 * modeset (as opposed to a vc4_update_plane() short circuit),
	 * then we need to wait for scanout to be done with our
	 * display lists before we free it and potentially reallocate
	 * and overwrite the dlist memory with a new modeset.
	 */
	state->legacy_cursor_update = false;

	drm_atomic_helper_wait_for_vblanks(dev, state);

	drm_atomic_helper_cleanup_planes(dev, state);

	drm_atomic_state_put(state);

	up(&vc4->async_modeset);

	kfree(c);
}

static void
vc4_atomic_complete_commit_seqno_cb(struct vc4_seqno_cb *cb)
{
	struct vc4_commit *c = container_of(cb, struct vc4_commit, cb);

	vc4_atomic_complete_commit(c);
}

static struct vc4_commit *commit_init(struct drm_atomic_state *state)
{
	struct vc4_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);

	if (!c)
		return NULL;
	c->dev = state->dev;
	c->state = state;

	return c;
}

/**
 * vc4_atomic_commit - commit validated state object
 * @dev: DRM device
 * @state: the driver state object
 * @nonblock: nonblocking commit
 *
 * This function commits a with drm_atomic_helper_check() pre-validated state
 * object. This can still fail when e.g. the framebuffer reservation fails. For
 * now this doesn't implement asynchronous commits.
 *
 * RETURNS
 * Zero for success or -errno.
 */
static int vc4_atomic_commit(struct drm_device *dev,
			     struct drm_atomic_state *state,
			     bool nonblock)
{
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	int ret;
	int i;
	uint64_t wait_seqno = 0;
	struct vc4_commit *c;
	struct drm_plane *plane;
	struct drm_plane_state *new_state;

	c = commit_init(state);
	if (!c)
		return -ENOMEM;

	/* Make sure that any outstanding modesets have finished. */
	if (nonblock) {
		struct drm_crtc *crtc;
		struct drm_crtc_state *crtc_state;
		unsigned long flags;
		bool busy = false;

		/*
		 * If there's an undispatched event to send then we're
		 * obviously still busy.  If there isn't, then we can
		 * unconditionally wait for the semaphore because it
		 * shouldn't be contended (for long).
		 *
		 * This is to prevent a race where queuing a new flip
		 * from userspace immediately on receipt of an event
		 * beats our clean-up and returns EBUSY.
		 */
		spin_lock_irqsave(&dev->event_lock, flags);
		for_each_crtc_in_state(state, crtc, crtc_state, i)
			busy |= vc4_event_pending(crtc);
		spin_unlock_irqrestore(&dev->event_lock, flags);
		if (busy) {
			kfree(c);
			return -EBUSY;
		}
	}
	ret = down_interruptible(&vc4->async_modeset);
	if (ret) {
		kfree(c);
		return ret;
	}

	ret = drm_atomic_helper_prepare_planes(dev, state);
	if (ret) {
		kfree(c);
		up(&vc4->async_modeset);
		return ret;
	}

	for_each_plane_in_state(state, plane, new_state, i) {
		if ((plane->state->fb != new_state->fb) && new_state->fb) {
			struct drm_gem_cma_object *cma_bo =
				drm_fb_cma_get_gem_obj(new_state->fb, 0);
			struct vc4_bo *bo = to_vc4_bo(&cma_bo->base);

			wait_seqno = max(bo->seqno, wait_seqno);
		}
	}

	/*
	 * This is the point of no return - everything below never fails except
	 * when the hw goes bonghits. Which means we can commit the new state on
	 * the software side now.
	 */

	drm_atomic_helper_swap_state(state, true);

	/*
	 * Everything below can be run asynchronously without the need to grab
	 * any modeset locks at all under one condition: It must be guaranteed
	 * that the asynchronous work has either been cancelled (if the driver
	 * supports it, which at least requires that the framebuffers get
	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
	 * before the new state gets committed on the software side with
	 * drm_atomic_helper_swap_state().
	 *
	 * This scheme allows new atomic state updates to be prepared and
	 * checked in parallel to the asynchronous completion of the previous
	 * update. Which is important since compositors need to figure out the
	 * composition of the next frame right after having submitted the
	 * current layout.
	 */

	drm_atomic_state_get(state);
	if (nonblock) {
		vc4_queue_seqno_cb(dev, &c->cb, wait_seqno,
				   vc4_atomic_complete_commit_seqno_cb);
	} else {
		vc4_wait_for_seqno(dev, wait_seqno, ~0ull, false);
		vc4_atomic_complete_commit(c);
	}

	return 0;
}

static const struct drm_mode_config_funcs vc4_mode_funcs = {
	.output_poll_changed = vc4_output_poll_changed,
	.atomic_check = drm_atomic_helper_check,
	.atomic_commit = vc4_atomic_commit,
	.fb_create = drm_fb_cma_create,
};

int vc4_kms_load(struct drm_device *dev)
{
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	int ret;

	sema_init(&vc4->async_modeset, 1);

	ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
	if (ret < 0) {
		dev_err(dev->dev, "failed to initialize vblank\n");
		return ret;
	}

	dev->mode_config.max_width = 2048;
	dev->mode_config.max_height = 2048;
	dev->mode_config.funcs = &vc4_mode_funcs;
	dev->mode_config.preferred_depth = 24;
	dev->mode_config.async_page_flip = true;

	drm_mode_config_reset(dev);

	vc4->fbdev = drm_fbdev_cma_init(dev, 32,
					dev->mode_config.num_crtc,
					dev->mode_config.num_connector);
	if (IS_ERR(vc4->fbdev))
		vc4->fbdev = NULL;

	drm_kms_helper_poll_init(dev);

	return 0;
}