aboutsummaryrefslogtreecommitdiff
path: root/xorg-server/hw/xfree86/drivers/modesetting/vblank.c
blob: 5031ef8ff5c87cbd3d1da39e0fa2712c548d8ed7 (plain)
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
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
/*
 * Copyright © 2013 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

/** @file vblank.c
 *
 * Support for tracking the DRM's vblank events.
 */

#ifdef HAVE_DIX_CONFIG_H
#include "dix-config.h"
#endif

#include <unistd.h>
#include <xf86.h>
#include <xf86Crtc.h>
#include <poll.h>
#include "driver.h"
#include "drmmode_display.h"

/**
 * Tracking for outstanding events queued to the kernel.
 *
 * Each list entry is a struct ms_drm_queue, which has a uint32_t
 * value generated from drm_seq that identifies the event and a
 * reference back to the crtc/screen associated with the event.  It's
 * done this way rather than in the screen because we want to be able
 * to drain the list of event handlers that should be called at server
 * regen time, even though we don't close the drm fd and have no way
 * to actually drain the kernel events.
 */
static struct xorg_list ms_drm_queue;
static uint32_t ms_drm_seq;

struct ms_pageflip {
    ScreenPtr screen;
    Bool crtc_for_msc_ust;
};

static void ms_box_intersect(BoxPtr dest, BoxPtr a, BoxPtr b)
{
    dest->x1 = a->x1 > b->x1 ? a->x1 : b->x1;
    dest->x2 = a->x2 < b->x2 ? a->x2 : b->x2;
    if (dest->x1 >= dest->x2) {
        dest->x1 = dest->x2 = dest->y1 = dest->y2 = 0;
        return;
    }

    dest->y1 = a->y1 > b->y1 ? a->y1 : b->y1;
    dest->y2 = a->y2 < b->y2 ? a->y2 : b->y2;
    if (dest->y1 >= dest->y2)
        dest->x1 = dest->x2 = dest->y1 = dest->y2 = 0;
}

static void ms_crtc_box(xf86CrtcPtr crtc, BoxPtr crtc_box)
{
    if (crtc->enabled) {
        crtc_box->x1 = crtc->x;
        crtc_box->x2 =
            crtc->x + xf86ModeWidth(&crtc->mode, crtc->rotation);
        crtc_box->y1 = crtc->y;
        crtc_box->y2 =
            crtc->y + xf86ModeHeight(&crtc->mode, crtc->rotation);
    } else
        crtc_box->x1 = crtc_box->x2 = crtc_box->y1 = crtc_box->y2 = 0;
}

static int ms_box_area(BoxPtr box)
{
    return (int)(box->x2 - box->x1) * (int)(box->y2 - box->y1);
}

/*
 * Return the crtc covering 'box'. If two crtcs cover a portion of
 * 'box', then prefer 'desired'. If 'desired' is NULL, then prefer the crtc
 * with greater coverage
 */

xf86CrtcPtr
ms_covering_crtc(ScrnInfoPtr scrn,
                 BoxPtr box, xf86CrtcPtr desired, BoxPtr crtc_box_ret)
{
    xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(scrn);
    xf86CrtcPtr crtc, best_crtc;
    int coverage, best_coverage;
    int c;
    BoxRec crtc_box, cover_box;

    best_crtc = NULL;
    best_coverage = 0;
    crtc_box_ret->x1 = 0;
    crtc_box_ret->x2 = 0;
    crtc_box_ret->y1 = 0;
    crtc_box_ret->y2 = 0;
    for (c = 0; c < xf86_config->num_crtc; c++) {
        crtc = xf86_config->crtc[c];

        /* If the CRTC is off, treat it as not covering */
        if (!crtc->enabled)
            continue;

        ms_crtc_box(crtc, &crtc_box);
        ms_box_intersect(&cover_box, &crtc_box, box);
        coverage = ms_box_area(&cover_box);
        if (coverage && crtc == desired) {
            *crtc_box_ret = crtc_box;
            return crtc;
        }
        if (coverage > best_coverage) {
            *crtc_box_ret = crtc_box;
            best_crtc = crtc;
            best_coverage = coverage;
        }
    }
    return best_crtc;
}

xf86CrtcPtr
ms_dri2_crtc_covering_drawable(DrawablePtr pDraw)
{
    ScreenPtr pScreen = pDraw->pScreen;
    ScrnInfoPtr pScrn = xf86ScreenToScrn(pScreen);
    BoxRec box, crtcbox;
    xf86CrtcPtr crtc;

    box.x1 = pDraw->x;
    box.y1 = pDraw->y;
    box.x2 = box.x1 + pDraw->width;
    box.y2 = box.y1 + pDraw->height;

    crtc = ms_covering_crtc(pScrn, &box, NULL, &crtcbox);

    /* Make sure the CRTC is valid and this is the real front buffer */
    if (crtc != NULL && !crtc->rotatedData)
        return crtc;

    return NULL;
}

static Bool
ms_get_kernel_ust_msc(xf86CrtcPtr crtc,
                      uint32_t *msc, uint64_t *ust)
{
    ScreenPtr screen = crtc->randr_crtc->pScreen;
    ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
    modesettingPtr ms = modesettingPTR(scrn);
    drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
    drmVBlank vbl;
    int ret;

    /* Get current count */
    vbl.request.type = DRM_VBLANK_RELATIVE | drmmode_crtc->vblank_pipe;
    vbl.request.sequence = 0;
    vbl.request.signal = 0;
    ret = drmWaitVBlank(ms->fd, &vbl);
    if (ret) {
        *msc = 0;
        *ust = 0;
        return FALSE;
    } else {
        *msc = vbl.reply.sequence;
        *ust = (CARD64) vbl.reply.tval_sec * 1000000 + vbl.reply.tval_usec;
        return TRUE;
    }
}

/**
 * Convert a 32-bit kernel MSC sequence number to a 64-bit local sequence
 * number, adding in the vblank_offset and high 32 bits, and dealing
 * with 64-bit wrapping
 */
uint64_t
ms_kernel_msc_to_crtc_msc(xf86CrtcPtr crtc, uint32_t sequence)
{
    drmmode_crtc_private_rec *drmmode_crtc = crtc->driver_private;
    sequence += drmmode_crtc->vblank_offset;

    if ((int32_t) (sequence - drmmode_crtc->msc_prev) < -0x40000000)
        drmmode_crtc->msc_high += 0x100000000L;
    drmmode_crtc->msc_prev = sequence;
    return drmmode_crtc->msc_high + sequence;
}

int
ms_get_crtc_ust_msc(xf86CrtcPtr crtc, CARD64 *ust, CARD64 *msc)
{
    uint32_t kernel_msc;

    if (!ms_get_kernel_ust_msc(crtc, &kernel_msc, ust))
        return BadMatch;
    *msc = ms_kernel_msc_to_crtc_msc(crtc, kernel_msc);

    return Success;
}

#define MAX_VBLANK_OFFSET       1000

/**
 * Convert a 64-bit adjusted MSC value into a 32-bit kernel sequence number,
 * removing the high 32 bits and subtracting out the vblank_offset term.
 *
 * This also updates the vblank_offset when it notices that the value should
 * change.
 */
uint32_t
ms_crtc_msc_to_kernel_msc(xf86CrtcPtr crtc, uint64_t expect)
{
    drmmode_crtc_private_rec *drmmode_crtc = crtc->driver_private;
    uint64_t msc;
    uint64_t ust;
    int64_t diff;

    if (ms_get_crtc_ust_msc(crtc, &ust, &msc) == Success) {
        diff = expect - msc;

        /* We're way off here, assume that the kernel has lost its mind
         * and smack the vblank back to something sensible
         */
        if (diff < -MAX_VBLANK_OFFSET || MAX_VBLANK_OFFSET < diff) {
            drmmode_crtc->vblank_offset += (int32_t) diff;
            if (drmmode_crtc->vblank_offset > -MAX_VBLANK_OFFSET &&
                drmmode_crtc->vblank_offset < MAX_VBLANK_OFFSET)
                drmmode_crtc->vblank_offset = 0;
        }
    }
    return (uint32_t) (expect - drmmode_crtc->vblank_offset);
}

/**
 * Check for pending DRM events and process them.
 */
static void
ms_drm_wakeup_handler(void *data, int err, void *mask)
{
    ScreenPtr screen = data;
    ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
    modesettingPtr ms = modesettingPTR(scrn);
    fd_set *read_mask = mask;

    if (data == NULL || err < 0)
        return;

    if (FD_ISSET(ms->fd, read_mask))
        drmHandleEvent(ms->fd, &ms->event_context);
}

/*
 * Enqueue a potential drm response; when the associated response
 * appears, we've got data to pass to the handler from here
 */
uint32_t
ms_drm_queue_alloc(xf86CrtcPtr crtc,
                   void *data,
                   ms_drm_handler_proc handler,
                   ms_drm_abort_proc abort)
{
    ScreenPtr screen = crtc->randr_crtc->pScreen;
    ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
    struct ms_drm_queue *q;

    q = calloc(1, sizeof(struct ms_drm_queue));

    if (!q)
        return 0;
    if (!ms_drm_seq)
        ++ms_drm_seq;
    q->seq = ms_drm_seq++;
    q->scrn = scrn;
    q->crtc = crtc;
    q->data = data;
    q->handler = handler;
    q->abort = abort;

    xorg_list_add(&q->list, &ms_drm_queue);

    return q->seq;
}

/**
 * Abort one queued DRM entry, removing it
 * from the list, calling the abort function and
 * freeing the memory
 */
static void
ms_drm_abort_one(struct ms_drm_queue *q)
{
        xorg_list_del(&q->list);
        q->abort(q->data);
        free(q);
}

/**
 * Abort all queued entries on a specific scrn, used
 * when resetting the X server
 */
static void
ms_drm_abort_scrn(ScrnInfoPtr scrn)
{
    struct ms_drm_queue *q, *tmp;

    xorg_list_for_each_entry_safe(q, tmp, &ms_drm_queue, list) {
        if (q->scrn == scrn)
            ms_drm_abort_one(q);
    }
}

/*
 * General DRM kernel handler. Looks for the matching sequence number in the
 * drm event queue and calls the handler for it.
 */
static void
ms_drm_handler(int fd, uint32_t frame, uint32_t sec, uint32_t usec,
               void *user_ptr)
{
    struct ms_drm_queue *q, *tmp;
    uint32_t user_data = (uint32_t) (intptr_t) user_ptr;

    xorg_list_for_each_entry_safe(q, tmp, &ms_drm_queue, list) {
        if (q->seq == user_data) {
            uint64_t msc;

            msc = ms_kernel_msc_to_crtc_msc(q->crtc, frame);
            xorg_list_del(&q->list);
            q->handler(msc, (uint64_t) sec * 1000000 + usec, q->data);
            free(q);
            break;
        }
    }
}

Bool
ms_vblank_screen_init(ScreenPtr screen)
{
    ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
    modesettingPtr ms = modesettingPTR(scrn);

    xorg_list_init(&ms_drm_queue);

    ms->event_context.version = DRM_EVENT_CONTEXT_VERSION;
    ms->event_context.vblank_handler = ms_drm_handler;
    ms->event_context.page_flip_handler = ms_drm_handler;

    /* We need to re-register the DRM fd for the synchronisation
     * feedback on every server generation, so perform the
     * registration within ScreenInit and not PreInit.
     */
    AddGeneralSocket(ms->fd);
    RegisterBlockAndWakeupHandlers((BlockHandlerProcPtr)NoopDDA,
                                   ms_drm_wakeup_handler, screen);

    return TRUE;
}

void
ms_vblank_close_screen(ScreenPtr screen)
{
    ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
    modesettingPtr ms = modesettingPTR(scrn);

    ms_drm_abort_scrn(scrn);

    RemoveBlockAndWakeupHandlers((BlockHandlerProcPtr)NoopDDA,
                                 ms_drm_wakeup_handler, screen);
    RemoveGeneralSocket(ms->fd);
}