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4ee36dc0 MA |
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/kernel.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/fb.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/vmalloc.h> | |
26 | #include <linux/mm.h> | |
27 | #include <asm/xen/hypervisor.h> | |
28 | #include <xen/events.h> | |
29 | #include <xen/page.h> | |
30 | #include <xen/interface/io/fbif.h> | |
31 | #include <xen/interface/io/protocols.h> | |
32 | #include <xen/xenbus.h> | |
33 | ||
34 | struct xenfb_info { | |
35 | unsigned char *fb; | |
36 | struct fb_info *fb_info; | |
37 | int x1, y1, x2, y2; /* dirty rectangle, | |
38 | protected by dirty_lock */ | |
39 | spinlock_t dirty_lock; | |
40 | int nr_pages; | |
41 | int irq; | |
42 | struct xenfb_page *page; | |
43 | unsigned long *mfns; | |
44 | int update_wanted; /* XENFB_TYPE_UPDATE wanted */ | |
45 | ||
46 | struct xenbus_device *xbdev; | |
47 | }; | |
48 | ||
49 | static u32 xenfb_mem_len = XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8; | |
50 | ||
51 | static int xenfb_remove(struct xenbus_device *); | |
52 | static void xenfb_init_shared_page(struct xenfb_info *); | |
53 | static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *); | |
54 | static void xenfb_disconnect_backend(struct xenfb_info *); | |
55 | ||
56 | static void xenfb_do_update(struct xenfb_info *info, | |
57 | int x, int y, int w, int h) | |
58 | { | |
59 | union xenfb_out_event event; | |
60 | u32 prod; | |
61 | ||
62 | event.type = XENFB_TYPE_UPDATE; | |
63 | event.update.x = x; | |
64 | event.update.y = y; | |
65 | event.update.width = w; | |
66 | event.update.height = h; | |
67 | ||
68 | prod = info->page->out_prod; | |
69 | /* caller ensures !xenfb_queue_full() */ | |
70 | mb(); /* ensure ring space available */ | |
71 | XENFB_OUT_RING_REF(info->page, prod) = event; | |
72 | wmb(); /* ensure ring contents visible */ | |
73 | info->page->out_prod = prod + 1; | |
74 | ||
75 | notify_remote_via_irq(info->irq); | |
76 | } | |
77 | ||
78 | static int xenfb_queue_full(struct xenfb_info *info) | |
79 | { | |
80 | u32 cons, prod; | |
81 | ||
82 | prod = info->page->out_prod; | |
83 | cons = info->page->out_cons; | |
84 | return prod - cons == XENFB_OUT_RING_LEN; | |
85 | } | |
86 | ||
87 | static void xenfb_refresh(struct xenfb_info *info, | |
88 | int x1, int y1, int w, int h) | |
89 | { | |
90 | unsigned long flags; | |
91 | int y2 = y1 + h - 1; | |
92 | int x2 = x1 + w - 1; | |
93 | ||
94 | if (!info->update_wanted) | |
95 | return; | |
96 | ||
97 | spin_lock_irqsave(&info->dirty_lock, flags); | |
98 | ||
99 | /* Combine with dirty rectangle: */ | |
100 | if (info->y1 < y1) | |
101 | y1 = info->y1; | |
102 | if (info->y2 > y2) | |
103 | y2 = info->y2; | |
104 | if (info->x1 < x1) | |
105 | x1 = info->x1; | |
106 | if (info->x2 > x2) | |
107 | x2 = info->x2; | |
108 | ||
109 | if (xenfb_queue_full(info)) { | |
110 | /* Can't send right now, stash it in the dirty rectangle */ | |
111 | info->x1 = x1; | |
112 | info->x2 = x2; | |
113 | info->y1 = y1; | |
114 | info->y2 = y2; | |
115 | spin_unlock_irqrestore(&info->dirty_lock, flags); | |
116 | return; | |
117 | } | |
118 | ||
119 | /* Clear dirty rectangle: */ | |
120 | info->x1 = info->y1 = INT_MAX; | |
121 | info->x2 = info->y2 = 0; | |
122 | ||
123 | spin_unlock_irqrestore(&info->dirty_lock, flags); | |
124 | ||
125 | if (x1 <= x2 && y1 <= y2) | |
126 | xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1); | |
127 | } | |
128 | ||
129 | static void xenfb_deferred_io(struct fb_info *fb_info, | |
130 | struct list_head *pagelist) | |
131 | { | |
132 | struct xenfb_info *info = fb_info->par; | |
133 | struct page *page; | |
134 | unsigned long beg, end; | |
135 | int y1, y2, miny, maxy; | |
136 | ||
137 | miny = INT_MAX; | |
138 | maxy = 0; | |
139 | list_for_each_entry(page, pagelist, lru) { | |
140 | beg = page->index << PAGE_SHIFT; | |
141 | end = beg + PAGE_SIZE - 1; | |
142 | y1 = beg / fb_info->fix.line_length; | |
143 | y2 = end / fb_info->fix.line_length; | |
144 | if (y2 >= fb_info->var.yres) | |
145 | y2 = fb_info->var.yres - 1; | |
146 | if (miny > y1) | |
147 | miny = y1; | |
148 | if (maxy < y2) | |
149 | maxy = y2; | |
150 | } | |
151 | xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1); | |
152 | } | |
153 | ||
154 | static struct fb_deferred_io xenfb_defio = { | |
155 | .delay = HZ / 20, | |
156 | .deferred_io = xenfb_deferred_io, | |
157 | }; | |
158 | ||
159 | static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green, | |
160 | unsigned blue, unsigned transp, | |
161 | struct fb_info *info) | |
162 | { | |
163 | u32 v; | |
164 | ||
165 | if (regno > info->cmap.len) | |
166 | return 1; | |
167 | ||
168 | #define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16) | |
169 | red = CNVT_TOHW(red, info->var.red.length); | |
170 | green = CNVT_TOHW(green, info->var.green.length); | |
171 | blue = CNVT_TOHW(blue, info->var.blue.length); | |
172 | transp = CNVT_TOHW(transp, info->var.transp.length); | |
173 | #undef CNVT_TOHW | |
174 | ||
175 | v = (red << info->var.red.offset) | | |
176 | (green << info->var.green.offset) | | |
177 | (blue << info->var.blue.offset); | |
178 | ||
179 | switch (info->var.bits_per_pixel) { | |
180 | case 16: | |
181 | case 24: | |
182 | case 32: | |
183 | ((u32 *)info->pseudo_palette)[regno] = v; | |
184 | break; | |
185 | } | |
186 | ||
187 | return 0; | |
188 | } | |
189 | ||
190 | static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect) | |
191 | { | |
192 | struct xenfb_info *info = p->par; | |
193 | ||
194 | sys_fillrect(p, rect); | |
195 | xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height); | |
196 | } | |
197 | ||
198 | static void xenfb_imageblit(struct fb_info *p, const struct fb_image *image) | |
199 | { | |
200 | struct xenfb_info *info = p->par; | |
201 | ||
202 | sys_imageblit(p, image); | |
203 | xenfb_refresh(info, image->dx, image->dy, image->width, image->height); | |
204 | } | |
205 | ||
206 | static void xenfb_copyarea(struct fb_info *p, const struct fb_copyarea *area) | |
207 | { | |
208 | struct xenfb_info *info = p->par; | |
209 | ||
210 | sys_copyarea(p, area); | |
211 | xenfb_refresh(info, area->dx, area->dy, area->width, area->height); | |
212 | } | |
213 | ||
214 | static ssize_t xenfb_write(struct fb_info *p, const char __user *buf, | |
215 | size_t count, loff_t *ppos) | |
216 | { | |
217 | struct xenfb_info *info = p->par; | |
218 | ssize_t res; | |
219 | ||
220 | res = fb_sys_write(p, buf, count, ppos); | |
221 | xenfb_refresh(info, 0, 0, info->page->width, info->page->height); | |
222 | return res; | |
223 | } | |
224 | ||
225 | static struct fb_ops xenfb_fb_ops = { | |
226 | .owner = THIS_MODULE, | |
227 | .fb_read = fb_sys_read, | |
228 | .fb_write = xenfb_write, | |
229 | .fb_setcolreg = xenfb_setcolreg, | |
230 | .fb_fillrect = xenfb_fillrect, | |
231 | .fb_copyarea = xenfb_copyarea, | |
232 | .fb_imageblit = xenfb_imageblit, | |
233 | }; | |
234 | ||
235 | static irqreturn_t xenfb_event_handler(int rq, void *dev_id) | |
236 | { | |
237 | /* | |
238 | * No in events recognized, simply ignore them all. | |
239 | * If you need to recognize some, see xen-kbdfront's | |
240 | * input_handler() for how to do that. | |
241 | */ | |
242 | struct xenfb_info *info = dev_id; | |
243 | struct xenfb_page *page = info->page; | |
244 | ||
245 | if (page->in_cons != page->in_prod) { | |
246 | info->page->in_cons = info->page->in_prod; | |
247 | notify_remote_via_irq(info->irq); | |
248 | } | |
249 | ||
250 | /* Flush dirty rectangle: */ | |
251 | xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX); | |
252 | ||
253 | return IRQ_HANDLED; | |
254 | } | |
255 | ||
256 | static int __devinit xenfb_probe(struct xenbus_device *dev, | |
257 | const struct xenbus_device_id *id) | |
258 | { | |
259 | struct xenfb_info *info; | |
260 | struct fb_info *fb_info; | |
261 | int ret; | |
262 | ||
263 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
264 | if (info == NULL) { | |
265 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
266 | return -ENOMEM; | |
267 | } | |
268 | dev->dev.driver_data = info; | |
269 | info->xbdev = dev; | |
270 | info->irq = -1; | |
271 | info->x1 = info->y1 = INT_MAX; | |
272 | spin_lock_init(&info->dirty_lock); | |
273 | ||
274 | info->fb = vmalloc(xenfb_mem_len); | |
275 | if (info->fb == NULL) | |
276 | goto error_nomem; | |
277 | memset(info->fb, 0, xenfb_mem_len); | |
278 | ||
279 | info->nr_pages = (xenfb_mem_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
280 | ||
281 | info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages); | |
282 | if (!info->mfns) | |
283 | goto error_nomem; | |
284 | ||
285 | /* set up shared page */ | |
286 | info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); | |
287 | if (!info->page) | |
288 | goto error_nomem; | |
289 | ||
290 | xenfb_init_shared_page(info); | |
291 | ||
292 | /* abusing framebuffer_alloc() to allocate pseudo_palette */ | |
293 | fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL); | |
294 | if (fb_info == NULL) | |
295 | goto error_nomem; | |
296 | ||
297 | /* complete the abuse: */ | |
298 | fb_info->pseudo_palette = fb_info->par; | |
299 | fb_info->par = info; | |
300 | ||
301 | fb_info->screen_base = info->fb; | |
302 | ||
303 | fb_info->fbops = &xenfb_fb_ops; | |
304 | fb_info->var.xres_virtual = fb_info->var.xres = info->page->width; | |
305 | fb_info->var.yres_virtual = fb_info->var.yres = info->page->height; | |
306 | fb_info->var.bits_per_pixel = info->page->depth; | |
307 | ||
308 | fb_info->var.red = (struct fb_bitfield){16, 8, 0}; | |
309 | fb_info->var.green = (struct fb_bitfield){8, 8, 0}; | |
310 | fb_info->var.blue = (struct fb_bitfield){0, 8, 0}; | |
311 | ||
312 | fb_info->var.activate = FB_ACTIVATE_NOW; | |
313 | fb_info->var.height = -1; | |
314 | fb_info->var.width = -1; | |
315 | fb_info->var.vmode = FB_VMODE_NONINTERLACED; | |
316 | ||
317 | fb_info->fix.visual = FB_VISUAL_TRUECOLOR; | |
318 | fb_info->fix.line_length = info->page->line_length; | |
319 | fb_info->fix.smem_start = 0; | |
320 | fb_info->fix.smem_len = xenfb_mem_len; | |
321 | strcpy(fb_info->fix.id, "xen"); | |
322 | fb_info->fix.type = FB_TYPE_PACKED_PIXELS; | |
323 | fb_info->fix.accel = FB_ACCEL_NONE; | |
324 | ||
325 | fb_info->flags = FBINFO_FLAG_DEFAULT; | |
326 | ||
327 | ret = fb_alloc_cmap(&fb_info->cmap, 256, 0); | |
328 | if (ret < 0) { | |
329 | framebuffer_release(fb_info); | |
330 | xenbus_dev_fatal(dev, ret, "fb_alloc_cmap"); | |
331 | goto error; | |
332 | } | |
333 | ||
334 | fb_info->fbdefio = &xenfb_defio; | |
335 | fb_deferred_io_init(fb_info); | |
336 | ||
337 | ret = register_framebuffer(fb_info); | |
338 | if (ret) { | |
339 | fb_deferred_io_cleanup(fb_info); | |
340 | fb_dealloc_cmap(&fb_info->cmap); | |
341 | framebuffer_release(fb_info); | |
342 | xenbus_dev_fatal(dev, ret, "register_framebuffer"); | |
343 | goto error; | |
344 | } | |
345 | info->fb_info = fb_info; | |
346 | ||
347 | ret = xenfb_connect_backend(dev, info); | |
348 | if (ret < 0) | |
349 | goto error; | |
350 | ||
351 | return 0; | |
352 | ||
353 | error_nomem: | |
354 | ret = -ENOMEM; | |
355 | xenbus_dev_fatal(dev, ret, "allocating device memory"); | |
356 | error: | |
357 | xenfb_remove(dev); | |
358 | return ret; | |
359 | } | |
360 | ||
361 | static int xenfb_resume(struct xenbus_device *dev) | |
362 | { | |
363 | struct xenfb_info *info = dev->dev.driver_data; | |
364 | ||
365 | xenfb_disconnect_backend(info); | |
366 | xenfb_init_shared_page(info); | |
367 | return xenfb_connect_backend(dev, info); | |
368 | } | |
369 | ||
370 | static int xenfb_remove(struct xenbus_device *dev) | |
371 | { | |
372 | struct xenfb_info *info = dev->dev.driver_data; | |
373 | ||
374 | xenfb_disconnect_backend(info); | |
375 | if (info->fb_info) { | |
376 | fb_deferred_io_cleanup(info->fb_info); | |
377 | unregister_framebuffer(info->fb_info); | |
378 | fb_dealloc_cmap(&info->fb_info->cmap); | |
379 | framebuffer_release(info->fb_info); | |
380 | } | |
381 | free_page((unsigned long)info->page); | |
382 | vfree(info->mfns); | |
383 | vfree(info->fb); | |
384 | kfree(info); | |
385 | ||
386 | return 0; | |
387 | } | |
388 | ||
389 | static unsigned long vmalloc_to_mfn(void *address) | |
390 | { | |
391 | return pfn_to_mfn(vmalloc_to_pfn(address)); | |
392 | } | |
393 | ||
394 | static void xenfb_init_shared_page(struct xenfb_info *info) | |
395 | { | |
396 | int i; | |
397 | ||
398 | for (i = 0; i < info->nr_pages; i++) | |
399 | info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE); | |
400 | ||
401 | info->page->pd[0] = vmalloc_to_mfn(info->mfns); | |
402 | info->page->pd[1] = 0; | |
403 | info->page->width = XENFB_WIDTH; | |
404 | info->page->height = XENFB_HEIGHT; | |
405 | info->page->depth = XENFB_DEPTH; | |
406 | info->page->line_length = (info->page->depth / 8) * info->page->width; | |
407 | info->page->mem_length = xenfb_mem_len; | |
408 | info->page->in_cons = info->page->in_prod = 0; | |
409 | info->page->out_cons = info->page->out_prod = 0; | |
410 | } | |
411 | ||
412 | static int xenfb_connect_backend(struct xenbus_device *dev, | |
413 | struct xenfb_info *info) | |
414 | { | |
415 | int ret, evtchn; | |
416 | struct xenbus_transaction xbt; | |
417 | ||
418 | ret = xenbus_alloc_evtchn(dev, &evtchn); | |
419 | if (ret) | |
420 | return ret; | |
421 | ret = bind_evtchn_to_irqhandler(evtchn, xenfb_event_handler, | |
422 | 0, dev->devicetype, info); | |
423 | if (ret < 0) { | |
424 | xenbus_free_evtchn(dev, evtchn); | |
425 | xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler"); | |
426 | return ret; | |
427 | } | |
428 | info->irq = ret; | |
429 | ||
430 | again: | |
431 | ret = xenbus_transaction_start(&xbt); | |
432 | if (ret) { | |
433 | xenbus_dev_fatal(dev, ret, "starting transaction"); | |
434 | return ret; | |
435 | } | |
436 | ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu", | |
437 | virt_to_mfn(info->page)); | |
438 | if (ret) | |
439 | goto error_xenbus; | |
440 | ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", | |
441 | evtchn); | |
442 | if (ret) | |
443 | goto error_xenbus; | |
444 | ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s", | |
445 | XEN_IO_PROTO_ABI_NATIVE); | |
446 | if (ret) | |
447 | goto error_xenbus; | |
448 | ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1"); | |
449 | if (ret) | |
450 | goto error_xenbus; | |
451 | ret = xenbus_transaction_end(xbt, 0); | |
452 | if (ret) { | |
453 | if (ret == -EAGAIN) | |
454 | goto again; | |
455 | xenbus_dev_fatal(dev, ret, "completing transaction"); | |
456 | return ret; | |
457 | } | |
458 | ||
459 | xenbus_switch_state(dev, XenbusStateInitialised); | |
460 | return 0; | |
461 | ||
462 | error_xenbus: | |
463 | xenbus_transaction_end(xbt, 1); | |
464 | xenbus_dev_fatal(dev, ret, "writing xenstore"); | |
465 | return ret; | |
466 | } | |
467 | ||
468 | static void xenfb_disconnect_backend(struct xenfb_info *info) | |
469 | { | |
470 | if (info->irq >= 0) | |
471 | unbind_from_irqhandler(info->irq, info); | |
472 | info->irq = -1; | |
473 | } | |
474 | ||
475 | static void xenfb_backend_changed(struct xenbus_device *dev, | |
476 | enum xenbus_state backend_state) | |
477 | { | |
478 | struct xenfb_info *info = dev->dev.driver_data; | |
479 | int val; | |
480 | ||
481 | switch (backend_state) { | |
482 | case XenbusStateInitialising: | |
483 | case XenbusStateInitialised: | |
484 | case XenbusStateUnknown: | |
485 | case XenbusStateClosed: | |
486 | break; | |
487 | ||
488 | case XenbusStateInitWait: | |
489 | InitWait: | |
490 | xenbus_switch_state(dev, XenbusStateConnected); | |
491 | break; | |
492 | ||
493 | case XenbusStateConnected: | |
494 | /* | |
495 | * Work around xenbus race condition: If backend goes | |
496 | * through InitWait to Connected fast enough, we can | |
497 | * get Connected twice here. | |
498 | */ | |
499 | if (dev->state != XenbusStateConnected) | |
500 | goto InitWait; /* no InitWait seen yet, fudge it */ | |
501 | ||
502 | if (xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
503 | "request-update", "%d", &val) < 0) | |
504 | val = 0; | |
505 | if (val) | |
506 | info->update_wanted = 1; | |
507 | break; | |
508 | ||
509 | case XenbusStateClosing: | |
510 | xenbus_frontend_closed(dev); | |
511 | break; | |
512 | } | |
513 | } | |
514 | ||
515 | static struct xenbus_device_id xenfb_ids[] = { | |
516 | { "vfb" }, | |
517 | { "" } | |
518 | }; | |
519 | ||
520 | static struct xenbus_driver xenfb = { | |
521 | .name = "vfb", | |
522 | .owner = THIS_MODULE, | |
523 | .ids = xenfb_ids, | |
524 | .probe = xenfb_probe, | |
525 | .remove = xenfb_remove, | |
526 | .resume = xenfb_resume, | |
527 | .otherend_changed = xenfb_backend_changed, | |
528 | }; | |
529 | ||
530 | static int __init xenfb_init(void) | |
531 | { | |
532 | if (!is_running_on_xen()) | |
533 | return -ENODEV; | |
534 | ||
535 | /* Nothing to do if running in dom0. */ | |
536 | if (is_initial_xendomain()) | |
537 | return -ENODEV; | |
538 | ||
539 | return xenbus_register_frontend(&xenfb); | |
540 | } | |
541 | ||
542 | static void __exit xenfb_cleanup(void) | |
543 | { | |
544 | xenbus_unregister_driver(&xenfb); | |
545 | } | |
546 | ||
547 | module_init(xenfb_init); | |
548 | module_exit(xenfb_cleanup); | |
549 | ||
550 | MODULE_LICENSE("GPL"); |