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Linux 3.11-rc3
[cris-mirror.git] / drivers / video / xen-fbfront.c
blobcd005c227a23cd3748ae4cdb22584474273e88c5
1 /*
2 * Xen para-virtual frame buffer device
3 *
4 * Copyright (C) 2005-2006 Anthony Liguori <aliguori@us.ibm.com>
5 * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
6 *
7 * Based on linux/drivers/video/q40fb.c
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file COPYING in the main directory of this archive for
11 * more details.
12 */
13
14 /*
15 * TODO:
16 *
17 * Switch to grant tables when they become capable of dealing with the
18 * frame buffer.
19 */
20
21 #include <linux/console.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/fb.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/mm.h>
29
30 #include <asm/xen/hypervisor.h>
31
32 #include <xen/xen.h>
33 #include <xen/events.h>
34 #include <xen/page.h>
35 #include <xen/interface/io/fbif.h>
36 #include <xen/interface/io/protocols.h>
37 #include <xen/xenbus.h>
38
39 struct xenfb_info {
40 unsigned char *fb;
41 struct fb_info *fb_info;
42 int x1, y1, x2, y2; /* dirty rectangle,
43 protected by dirty_lock */
44 spinlock_t dirty_lock;
45 int nr_pages;
46 int irq;
47 struct xenfb_page *page;
48 unsigned long *mfns;
49 int update_wanted; /* XENFB_TYPE_UPDATE wanted */
50 int feature_resize; /* XENFB_TYPE_RESIZE ok */
51 struct xenfb_resize resize; /* protected by resize_lock */
52 int resize_dpy; /* ditto */
53 spinlock_t resize_lock;
54
55 struct xenbus_device *xbdev;
56 };
57
58 #define XENFB_DEFAULT_FB_LEN (XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8)
59
60 enum { KPARAM_MEM, KPARAM_WIDTH, KPARAM_HEIGHT, KPARAM_CNT };
61 static int video[KPARAM_CNT] = { 2, XENFB_WIDTH, XENFB_HEIGHT };
62 module_param_array(video, int, NULL, 0);
63 MODULE_PARM_DESC(video,
64 "Video memory size in MB, width, height in pixels (default 2,800,600)");
65
66 static void xenfb_make_preferred_console(void);
67 static int xenfb_remove(struct xenbus_device *);
68 static void xenfb_init_shared_page(struct xenfb_info *, struct fb_info *);
69 static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *);
70 static void xenfb_disconnect_backend(struct xenfb_info *);
71
72 static void xenfb_send_event(struct xenfb_info *info,
73 union xenfb_out_event *event)
74 {
75 u32 prod;
76
77 prod = info->page->out_prod;
78 /* caller ensures !xenfb_queue_full() */
79 mb(); /* ensure ring space available */
80 XENFB_OUT_RING_REF(info->page, prod) = *event;
81 wmb(); /* ensure ring contents visible */
82 info->page->out_prod = prod + 1;
83
84 notify_remote_via_irq(info->irq);
85 }
86
87 static void xenfb_do_update(struct xenfb_info *info,
88 int x, int y, int w, int h)
89 {
90 union xenfb_out_event event;
91
92 memset(&event, 0, sizeof(event));
93 event.type = XENFB_TYPE_UPDATE;
94 event.update.x = x;
95 event.update.y = y;
96 event.update.width = w;
97 event.update.height = h;
98
99 /* caller ensures !xenfb_queue_full() */
100 xenfb_send_event(info, &event);
101 }
102
103 static void xenfb_do_resize(struct xenfb_info *info)
104 {
105 union xenfb_out_event event;
106
107 memset(&event, 0, sizeof(event));
108 event.resize = info->resize;
109
110 /* caller ensures !xenfb_queue_full() */
111 xenfb_send_event(info, &event);
112 }
113
114 static int xenfb_queue_full(struct xenfb_info *info)
115 {
116 u32 cons, prod;
117
118 prod = info->page->out_prod;
119 cons = info->page->out_cons;
120 return prod - cons == XENFB_OUT_RING_LEN;
121 }
122
123 static void xenfb_handle_resize_dpy(struct xenfb_info *info)
124 {
125 unsigned long flags;
126
127 spin_lock_irqsave(&info->resize_lock, flags);
128 if (info->resize_dpy) {
129 if (!xenfb_queue_full(info)) {
130 info->resize_dpy = 0;
131 xenfb_do_resize(info);
132 }
133 }
134 spin_unlock_irqrestore(&info->resize_lock, flags);
135 }
136
137 static void xenfb_refresh(struct xenfb_info *info,
138 int x1, int y1, int w, int h)
139 {
140 unsigned long flags;
141 int x2 = x1 + w - 1;
142 int y2 = y1 + h - 1;
143
144 xenfb_handle_resize_dpy(info);
145
146 if (!info->update_wanted)
147 return;
148
149 spin_lock_irqsave(&info->dirty_lock, flags);
150
151 /* Combine with dirty rectangle: */
152 if (info->y1 < y1)
153 y1 = info->y1;
154 if (info->y2 > y2)
155 y2 = info->y2;
156 if (info->x1 < x1)
157 x1 = info->x1;
158 if (info->x2 > x2)
159 x2 = info->x2;
160
161 if (xenfb_queue_full(info)) {
162 /* Can't send right now, stash it in the dirty rectangle */
163 info->x1 = x1;
164 info->x2 = x2;
165 info->y1 = y1;
166 info->y2 = y2;
167 spin_unlock_irqrestore(&info->dirty_lock, flags);
168 return;
169 }
170
171 /* Clear dirty rectangle: */
172 info->x1 = info->y1 = INT_MAX;
173 info->x2 = info->y2 = 0;
174
175 spin_unlock_irqrestore(&info->dirty_lock, flags);
176
177 if (x1 <= x2 && y1 <= y2)
178 xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1);
179 }
180
181 static void xenfb_deferred_io(struct fb_info *fb_info,
182 struct list_head *pagelist)
183 {
184 struct xenfb_info *info = fb_info->par;
185 struct page *page;
186 unsigned long beg, end;
187 int y1, y2, miny, maxy;
188
189 miny = INT_MAX;
190 maxy = 0;
191 list_for_each_entry(page, pagelist, lru) {
192 beg = page->index << PAGE_SHIFT;
193 end = beg + PAGE_SIZE - 1;
194 y1 = beg / fb_info->fix.line_length;
195 y2 = end / fb_info->fix.line_length;
196 if (y2 >= fb_info->var.yres)
197 y2 = fb_info->var.yres - 1;
198 if (miny > y1)
199 miny = y1;
200 if (maxy < y2)
201 maxy = y2;
202 }
203 xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1);
204 }
205
206 static struct fb_deferred_io xenfb_defio = {
207 .delay = HZ / 20,
208 .deferred_io = xenfb_deferred_io,
209 };
210
211 static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green,
212 unsigned blue, unsigned transp,
213 struct fb_info *info)
214 {
215 u32 v;
216
217 if (regno > info->cmap.len)
218 return 1;
219
220 #define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
221 red = CNVT_TOHW(red, info->var.red.length);
222 green = CNVT_TOHW(green, info->var.green.length);
223 blue = CNVT_TOHW(blue, info->var.blue.length);
224 transp = CNVT_TOHW(transp, info->var.transp.length);
225 #undef CNVT_TOHW
226
227 v = (red << info->var.red.offset) |
228 (green << info->var.green.offset) |
229 (blue << info->var.blue.offset);
230
231 switch (info->var.bits_per_pixel) {
232 case 16:
233 case 24:
234 case 32:
235 ((u32 *)info->pseudo_palette)[regno] = v;
236 break;
237 }
238
239 return 0;
240 }
241
242 static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
243 {
244 struct xenfb_info *info = p->par;
245
246 sys_fillrect(p, rect);
247 xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height);
248 }
249
250 static void xenfb_imageblit(struct fb_info *p, const struct fb_image *image)
251 {
252 struct xenfb_info *info = p->par;
253
254 sys_imageblit(p, image);
255 xenfb_refresh(info, image->dx, image->dy, image->width, image->height);
256 }
257
258 static void xenfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
259 {
260 struct xenfb_info *info = p->par;
261
262 sys_copyarea(p, area);
263 xenfb_refresh(info, area->dx, area->dy, area->width, area->height);
264 }
265
266 static ssize_t xenfb_write(struct fb_info *p, const char __user *buf,
267 size_t count, loff_t *ppos)
268 {
269 struct xenfb_info *info = p->par;
270 ssize_t res;
271
272 res = fb_sys_write(p, buf, count, ppos);
273 xenfb_refresh(info, 0, 0, info->page->width, info->page->height);
274 return res;
275 }
276
277 static int
278 xenfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
279 {
280 struct xenfb_info *xenfb_info;
281 int required_mem_len;
282
283 xenfb_info = info->par;
284
285 if (!xenfb_info->feature_resize) {
286 if (var->xres == video[KPARAM_WIDTH] &&
287 var->yres == video[KPARAM_HEIGHT] &&
288 var->bits_per_pixel == xenfb_info->page->depth) {
289 return 0;
290 }
291 return -EINVAL;
292 }
293
294 /* Can't resize past initial width and height */
295 if (var->xres > video[KPARAM_WIDTH] || var->yres > video[KPARAM_HEIGHT])
296 return -EINVAL;
297
298 required_mem_len = var->xres * var->yres * xenfb_info->page->depth / 8;
299 if (var->bits_per_pixel == xenfb_info->page->depth &&
300 var->xres <= info->fix.line_length / (XENFB_DEPTH / 8) &&
301 required_mem_len <= info->fix.smem_len) {
302 var->xres_virtual = var->xres;
303 var->yres_virtual = var->yres;
304 return 0;
305 }
306 return -EINVAL;
307 }
308
309 static int xenfb_set_par(struct fb_info *info)
310 {
311 struct xenfb_info *xenfb_info;
312 unsigned long flags;
313
314 xenfb_info = info->par;
315
316 spin_lock_irqsave(&xenfb_info->resize_lock, flags);
317 xenfb_info->resize.type = XENFB_TYPE_RESIZE;
318 xenfb_info->resize.width = info->var.xres;
319 xenfb_info->resize.height = info->var.yres;
320 xenfb_info->resize.stride = info->fix.line_length;
321 xenfb_info->resize.depth = info->var.bits_per_pixel;
322 xenfb_info->resize.offset = 0;
323 xenfb_info->resize_dpy = 1;
324 spin_unlock_irqrestore(&xenfb_info->resize_lock, flags);
325 return 0;
326 }
327
328 static struct fb_ops xenfb_fb_ops = {
329 .owner = THIS_MODULE,
330 .fb_read = fb_sys_read,
331 .fb_write = xenfb_write,
332 .fb_setcolreg = xenfb_setcolreg,
333 .fb_fillrect = xenfb_fillrect,
334 .fb_copyarea = xenfb_copyarea,
335 .fb_imageblit = xenfb_imageblit,
336 .fb_check_var = xenfb_check_var,
337 .fb_set_par = xenfb_set_par,
338 };
339
340 static irqreturn_t xenfb_event_handler(int rq, void *dev_id)
341 {
342 /*
343 * No in events recognized, simply ignore them all.
344 * If you need to recognize some, see xen-kbdfront's
345 * input_handler() for how to do that.
346 */
347 struct xenfb_info *info = dev_id;
348 struct xenfb_page *page = info->page;
349
350 if (page->in_cons != page->in_prod) {
351 info->page->in_cons = info->page->in_prod;
352 notify_remote_via_irq(info->irq);
353 }
354
355 /* Flush dirty rectangle: */
356 xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX);
357
358 return IRQ_HANDLED;
359 }
360
361 static int xenfb_probe(struct xenbus_device *dev,
362 const struct xenbus_device_id *id)
363 {
364 struct xenfb_info *info;
365 struct fb_info *fb_info;
366 int fb_size;
367 int val;
368 int ret = 0;
369
370 info = kzalloc(sizeof(*info), GFP_KERNEL);
371 if (info == NULL) {
372 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
373 return -ENOMEM;
374 }
375
376 /* Limit kernel param videoram amount to what is in xenstore */
377 if (xenbus_scanf(XBT_NIL, dev->otherend, "videoram", "%d", &val) == 1) {
378 if (val < video[KPARAM_MEM])
379 video[KPARAM_MEM] = val;
380 }
381
382 /* If requested res does not fit in available memory, use default */
383 fb_size = video[KPARAM_MEM] * 1024 * 1024;
384 if (video[KPARAM_WIDTH] * video[KPARAM_HEIGHT] * XENFB_DEPTH / 8
385 > fb_size) {
386 video[KPARAM_WIDTH] = XENFB_WIDTH;
387 video[KPARAM_HEIGHT] = XENFB_HEIGHT;
388 fb_size = XENFB_DEFAULT_FB_LEN;
389 }
390
391 dev_set_drvdata(&dev->dev, info);
392 info->xbdev = dev;
393 info->irq = -1;
394 info->x1 = info->y1 = INT_MAX;
395 spin_lock_init(&info->dirty_lock);
396 spin_lock_init(&info->resize_lock);
397
398 info->fb = vzalloc(fb_size);
399 if (info->fb == NULL)
400 goto error_nomem;
401
402 info->nr_pages = (fb_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
403
404 info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages);
405 if (!info->mfns)
406 goto error_nomem;
407
408 /* set up shared page */
409 info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
410 if (!info->page)
411 goto error_nomem;
412
413 /* abusing framebuffer_alloc() to allocate pseudo_palette */
414 fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);
415 if (fb_info == NULL)
416 goto error_nomem;
417
418 /* complete the abuse: */
419 fb_info->pseudo_palette = fb_info->par;
420 fb_info->par = info;
421
422 fb_info->screen_base = info->fb;
423
424 fb_info->fbops = &xenfb_fb_ops;
425 fb_info->var.xres_virtual = fb_info->var.xres = video[KPARAM_WIDTH];
426 fb_info->var.yres_virtual = fb_info->var.yres = video[KPARAM_HEIGHT];
427 fb_info->var.bits_per_pixel = XENFB_DEPTH;
428
429 fb_info->var.red = (struct fb_bitfield){16, 8, 0};
430 fb_info->var.green = (struct fb_bitfield){8, 8, 0};
431 fb_info->var.blue = (struct fb_bitfield){0, 8, 0};
432
433 fb_info->var.activate = FB_ACTIVATE_NOW;
434 fb_info->var.height = -1;
435 fb_info->var.width = -1;
436 fb_info->var.vmode = FB_VMODE_NONINTERLACED;
437
438 fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
439 fb_info->fix.line_length = fb_info->var.xres * XENFB_DEPTH / 8;
440 fb_info->fix.smem_start = 0;
441 fb_info->fix.smem_len = fb_size;
442 strcpy(fb_info->fix.id, "xen");
443 fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
444 fb_info->fix.accel = FB_ACCEL_NONE;
445
446 fb_info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
447
448 ret = fb_alloc_cmap(&fb_info->cmap, 256, 0);
449 if (ret < 0) {
450 framebuffer_release(fb_info);
451 xenbus_dev_fatal(dev, ret, "fb_alloc_cmap");
452 goto error;
453 }
454
455 fb_info->fbdefio = &xenfb_defio;
456 fb_deferred_io_init(fb_info);
457
458 xenfb_init_shared_page(info, fb_info);
459
460 ret = xenfb_connect_backend(dev, info);
461 if (ret < 0) {
462 xenbus_dev_fatal(dev, ret, "xenfb_connect_backend");
463 goto error_fb;
464 }
465
466 ret = register_framebuffer(fb_info);
467 if (ret) {
468 xenbus_dev_fatal(dev, ret, "register_framebuffer");
469 goto error_fb;
470 }
471 info->fb_info = fb_info;
472
473 xenfb_make_preferred_console();
474 return 0;
475
476 error_fb:
477 fb_deferred_io_cleanup(fb_info);
478 fb_dealloc_cmap(&fb_info->cmap);
479 framebuffer_release(fb_info);
480 error_nomem:
481 if (!ret) {
482 ret = -ENOMEM;
483 xenbus_dev_fatal(dev, ret, "allocating device memory");
484 }
485 error:
486 xenfb_remove(dev);
487 return ret;
488 }
489
490 static void xenfb_make_preferred_console(void)
491 {
492 struct console *c;
493
494 if (console_set_on_cmdline)
495 return;
496
497 console_lock();
498 for_each_console(c) {
499 if (!strcmp(c->name, "tty") && c->index == 0)
500 break;
501 }
502 console_unlock();
503 if (c) {
504 unregister_console(c);
505 c->flags |= CON_CONSDEV;
506 c->flags &= ~CON_PRINTBUFFER; /* don't print again */
507 register_console(c);
508 }
509 }
510
511 static int xenfb_resume(struct xenbus_device *dev)
512 {
513 struct xenfb_info *info = dev_get_drvdata(&dev->dev);
514
515 xenfb_disconnect_backend(info);
516 xenfb_init_shared_page(info, info->fb_info);
517 return xenfb_connect_backend(dev, info);
518 }
519
520 static int xenfb_remove(struct xenbus_device *dev)
521 {
522 struct xenfb_info *info = dev_get_drvdata(&dev->dev);
523
524 xenfb_disconnect_backend(info);
525 if (info->fb_info) {
526 fb_deferred_io_cleanup(info->fb_info);
527 unregister_framebuffer(info->fb_info);
528 fb_dealloc_cmap(&info->fb_info->cmap);
529 framebuffer_release(info->fb_info);
530 }
531 free_page((unsigned long)info->page);
532 vfree(info->mfns);
533 vfree(info->fb);
534 kfree(info);
535
536 return 0;
537 }
538
539 static unsigned long vmalloc_to_mfn(void *address)
540 {
541 return pfn_to_mfn(vmalloc_to_pfn(address));
542 }
543
544 static void xenfb_init_shared_page(struct xenfb_info *info,
545 struct fb_info *fb_info)
546 {
547 int i;
548 int epd = PAGE_SIZE / sizeof(info->mfns[0]);
549
550 for (i = 0; i < info->nr_pages; i++)
551 info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE);
552
553 for (i = 0; i * epd < info->nr_pages; i++)
554 info->page->pd[i] = vmalloc_to_mfn(&info->mfns[i * epd]);
555
556 info->page->width = fb_info->var.xres;
557 info->page->height = fb_info->var.yres;
558 info->page->depth = fb_info->var.bits_per_pixel;
559 info->page->line_length = fb_info->fix.line_length;
560 info->page->mem_length = fb_info->fix.smem_len;
561 info->page->in_cons = info->page->in_prod = 0;
562 info->page->out_cons = info->page->out_prod = 0;
563 }
564
565 static int xenfb_connect_backend(struct xenbus_device *dev,
566 struct xenfb_info *info)
567 {
568 int ret, evtchn, irq;
569 struct xenbus_transaction xbt;
570
571 ret = xenbus_alloc_evtchn(dev, &evtchn);
572 if (ret)
573 return ret;
574 irq = bind_evtchn_to_irqhandler(evtchn, xenfb_event_handler,
575 0, dev->devicetype, info);
576 if (irq < 0) {
577 xenbus_free_evtchn(dev, evtchn);
578 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
579 return irq;
580 }
581 again:
582 ret = xenbus_transaction_start(&xbt);
583 if (ret) {
584 xenbus_dev_fatal(dev, ret, "starting transaction");
585 goto unbind_irq;
586 }
587 ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
588 virt_to_mfn(info->page));
589 if (ret)
590 goto error_xenbus;
591 ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
592 evtchn);
593 if (ret)
594 goto error_xenbus;
595 ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
596 XEN_IO_PROTO_ABI_NATIVE);
597 if (ret)
598 goto error_xenbus;
599 ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1");
600 if (ret)
601 goto error_xenbus;
602 ret = xenbus_transaction_end(xbt, 0);
603 if (ret) {
604 if (ret == -EAGAIN)
605 goto again;
606 xenbus_dev_fatal(dev, ret, "completing transaction");
607 goto unbind_irq;
608 }
609
610 xenbus_switch_state(dev, XenbusStateInitialised);
611 info->irq = irq;
612 return 0;
613
614 error_xenbus:
615 xenbus_transaction_end(xbt, 1);
616 xenbus_dev_fatal(dev, ret, "writing xenstore");
617 unbind_irq:
618 unbind_from_irqhandler(irq, info);
619 return ret;
620 }
621
622 static void xenfb_disconnect_backend(struct xenfb_info *info)
623 {
624 /* Prevent xenfb refresh */
625 info->update_wanted = 0;
626 if (info->irq >= 0)
627 unbind_from_irqhandler(info->irq, info);
628 info->irq = -1;
629 }
630
631 static void xenfb_backend_changed(struct xenbus_device *dev,
632 enum xenbus_state backend_state)
633 {
634 struct xenfb_info *info = dev_get_drvdata(&dev->dev);
635 int val;
636
637 switch (backend_state) {
638 case XenbusStateInitialising:
639 case XenbusStateInitialised:
640 case XenbusStateReconfiguring:
641 case XenbusStateReconfigured:
642 case XenbusStateUnknown:
643 break;
644
645 case XenbusStateInitWait:
646 InitWait:
647 xenbus_switch_state(dev, XenbusStateConnected);
648 break;
649
650 case XenbusStateConnected:
651 /*
652 * Work around xenbus race condition: If backend goes
653 * through InitWait to Connected fast enough, we can
654 * get Connected twice here.
655 */
656 if (dev->state != XenbusStateConnected)
657 goto InitWait; /* no InitWait seen yet, fudge it */
658
659 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
660 "request-update", "%d", &val) < 0)
661 val = 0;
662 if (val)
663 info->update_wanted = 1;
664
665 if (xenbus_scanf(XBT_NIL, dev->otherend,
666 "feature-resize", "%d", &val) < 0)
667 val = 0;
668 info->feature_resize = val;
669 break;
670
671 case XenbusStateClosed:
672 if (dev->state == XenbusStateClosed)
673 break;
674 /* Missed the backend's CLOSING state -- fallthrough */
675 case XenbusStateClosing:
676 xenbus_frontend_closed(dev);
677 break;
678 }
679 }
680
681 static const struct xenbus_device_id xenfb_ids[] = {
682 { "vfb" },
683 { "" }
684 };
685
686 static DEFINE_XENBUS_DRIVER(xenfb, ,
687 .probe = xenfb_probe,
688 .remove = xenfb_remove,
689 .resume = xenfb_resume,
690 .otherend_changed = xenfb_backend_changed,
691 );
692
693 static int __init xenfb_init(void)
694 {
695 if (!xen_pv_domain())
696 return -ENODEV;
697
698 /* Nothing to do if running in dom0. */
699 if (xen_initial_domain())
700 return -ENODEV;
701
702 return xenbus_register_frontend(&xenfb_driver);
703 }
704
705 static void __exit xenfb_cleanup(void)
706 {
707 xenbus_unregister_driver(&xenfb_driver);
708 }
709
710 module_init(xenfb_init);
711 module_exit(xenfb_cleanup);
712
713 MODULE_DESCRIPTION("Xen virtual framebuffer device frontend");
714 MODULE_LICENSE("GPL");
715 MODULE_ALIAS("xen:vfb");
CRIS linux kernel tree