1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21#include <linux/console.h>
22#include <linux/delay.h>
23#include <linux/err.h>
24#include <linux/irq.h>
25#include <linux/init.h>
26#include <linux/types.h>
27#include <linux/list.h>
28
29#include <asm/io.h>
30#include <asm/xen/hypervisor.h>
31
32#include <xen/xen.h>
33#include <xen/interface/xen.h>
34#include <xen/hvm.h>
35#include <xen/grant_table.h>
36#include <xen/page.h>
37#include <xen/events.h>
38#include <xen/interface/io/console.h>
39#include <xen/interface/sched.h>
40#include <xen/hvc-console.h>
41#include <xen/xenbus.h>
42
43#include "hvc_console.h"
44
45#define HVC_COOKIE 0x58656e
46
47struct xencons_info {
48 struct list_head list;
49 struct xenbus_device *xbdev;
50 struct xencons_interface *intf;
51 unsigned int evtchn;
52 struct hvc_struct *hvc;
53 int irq;
54 int vtermno;
55 grant_ref_t gntref;
56};
57
58static LIST_HEAD(xenconsoles);
59static DEFINE_SPINLOCK(xencons_lock);
60
61
62
63static struct xencons_info *vtermno_to_xencons(int vtermno)
64{
65 struct xencons_info *entry, *n, *ret = NULL;
66
67 if (list_empty(&xenconsoles))
68 return NULL;
69
70 list_for_each_entry_safe(entry, n, &xenconsoles, list) {
71 if (entry->vtermno == vtermno) {
72 ret = entry;
73 break;
74 }
75 }
76
77 return ret;
78}
79
80static inline int xenbus_devid_to_vtermno(int devid)
81{
82 return devid + HVC_COOKIE;
83}
84
85static inline void notify_daemon(struct xencons_info *cons)
86{
87
88 notify_remote_via_evtchn(cons->evtchn);
89}
90
91static int __write_console(struct xencons_info *xencons,
92 const char *data, int len)
93{
94 XENCONS_RING_IDX cons, prod;
95 struct xencons_interface *intf = xencons->intf;
96 int sent = 0;
97
98 cons = intf->out_cons;
99 prod = intf->out_prod;
100 mb();
101 BUG_ON((prod - cons) > sizeof(intf->out));
102
103 while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
104 intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
105
106 wmb();
107 intf->out_prod = prod;
108
109 if (sent)
110 notify_daemon(xencons);
111 return sent;
112}
113
114static int domU_write_console(uint32_t vtermno, const char *data, int len)
115{
116 int ret = len;
117 struct xencons_info *cons = vtermno_to_xencons(vtermno);
118 if (cons == NULL)
119 return -EINVAL;
120
121
122
123
124
125
126
127 while (len) {
128 int sent = __write_console(cons, data, len);
129
130 data += sent;
131 len -= sent;
132
133 if (unlikely(len))
134 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
135 }
136
137 return ret;
138}
139
140static int domU_read_console(uint32_t vtermno, char *buf, int len)
141{
142 struct xencons_interface *intf;
143 XENCONS_RING_IDX cons, prod;
144 int recv = 0;
145 struct xencons_info *xencons = vtermno_to_xencons(vtermno);
146 if (xencons == NULL)
147 return -EINVAL;
148 intf = xencons->intf;
149
150 cons = intf->in_cons;
151 prod = intf->in_prod;
152 mb();
153 BUG_ON((prod - cons) > sizeof(intf->in));
154
155 while (cons != prod && recv < len)
156 buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
157
158 mb();
159 intf->in_cons = cons;
160
161 notify_daemon(xencons);
162 return recv;
163}
164
165static struct hv_ops domU_hvc_ops = {
166 .get_chars = domU_read_console,
167 .put_chars = domU_write_console,
168 .notifier_add = notifier_add_irq,
169 .notifier_del = notifier_del_irq,
170 .notifier_hangup = notifier_hangup_irq,
171};
172
173static int dom0_read_console(uint32_t vtermno, char *buf, int len)
174{
175 return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
176}
177
178
179
180
181
182static int dom0_write_console(uint32_t vtermno, const char *str, int len)
183{
184 int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
185 if (rc < 0)
186 return 0;
187
188 return len;
189}
190
191static struct hv_ops dom0_hvc_ops = {
192 .get_chars = dom0_read_console,
193 .put_chars = dom0_write_console,
194 .notifier_add = notifier_add_irq,
195 .notifier_del = notifier_del_irq,
196 .notifier_hangup = notifier_hangup_irq,
197};
198
199static int xen_hvm_console_init(void)
200{
201 int r;
202 uint64_t v = 0;
203 unsigned long mfn;
204 struct xencons_info *info;
205
206 if (!xen_hvm_domain())
207 return -ENODEV;
208
209 info = vtermno_to_xencons(HVC_COOKIE);
210 if (!info) {
211 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
212 if (!info)
213 return -ENOMEM;
214 } else if (info->intf != NULL) {
215
216 return 0;
217 }
218
219
220
221
222
223
224 r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
225 if (r < 0 || v == 0)
226 goto err;
227 info->evtchn = v;
228 v = 0;
229 r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
230 if (r < 0 || v == 0)
231 goto err;
232 mfn = v;
233 info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
234 if (info->intf == NULL)
235 goto err;
236 info->vtermno = HVC_COOKIE;
237
238 spin_lock(&xencons_lock);
239 list_add_tail(&info->list, &xenconsoles);
240 spin_unlock(&xencons_lock);
241
242 return 0;
243err:
244 kfree(info);
245 return -ENODEV;
246}
247
248static int xen_pv_console_init(void)
249{
250 struct xencons_info *info;
251
252 if (!xen_pv_domain())
253 return -ENODEV;
254
255 if (!xen_start_info->console.domU.evtchn)
256 return -ENODEV;
257
258 info = vtermno_to_xencons(HVC_COOKIE);
259 if (!info) {
260 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
261 if (!info)
262 return -ENOMEM;
263 } else if (info->intf != NULL) {
264
265 return 0;
266 }
267 info->evtchn = xen_start_info->console.domU.evtchn;
268 info->intf = mfn_to_virt(xen_start_info->console.domU.mfn);
269 info->vtermno = HVC_COOKIE;
270
271 spin_lock(&xencons_lock);
272 list_add_tail(&info->list, &xenconsoles);
273 spin_unlock(&xencons_lock);
274
275 return 0;
276}
277
278static int xen_initial_domain_console_init(void)
279{
280 struct xencons_info *info;
281
282 if (!xen_initial_domain())
283 return -ENODEV;
284
285 info = vtermno_to_xencons(HVC_COOKIE);
286 if (!info) {
287 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
288 if (!info)
289 return -ENOMEM;
290 }
291
292 info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
293 info->vtermno = HVC_COOKIE;
294
295 spin_lock(&xencons_lock);
296 list_add_tail(&info->list, &xenconsoles);
297 spin_unlock(&xencons_lock);
298
299 return 0;
300}
301
302void xen_console_resume(void)
303{
304 struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
305 if (info != NULL && info->irq)
306 rebind_evtchn_irq(info->evtchn, info->irq);
307}
308
309static void xencons_disconnect_backend(struct xencons_info *info)
310{
311 if (info->irq > 0)
312 unbind_from_irqhandler(info->irq, NULL);
313 info->irq = 0;
314 if (info->evtchn > 0)
315 xenbus_free_evtchn(info->xbdev, info->evtchn);
316 info->evtchn = 0;
317 if (info->gntref > 0)
318 gnttab_free_grant_references(info->gntref);
319 info->gntref = 0;
320 if (info->hvc != NULL)
321 hvc_remove(info->hvc);
322 info->hvc = NULL;
323}
324
325static void xencons_free(struct xencons_info *info)
326{
327 free_page((unsigned long)info->intf);
328 info->intf = NULL;
329 info->vtermno = 0;
330 kfree(info);
331}
332
333static int xen_console_remove(struct xencons_info *info)
334{
335 xencons_disconnect_backend(info);
336 spin_lock(&xencons_lock);
337 list_del(&info->list);
338 spin_unlock(&xencons_lock);
339 if (info->xbdev != NULL)
340 xencons_free(info);
341 else {
342 if (xen_hvm_domain())
343 iounmap(info->intf);
344 kfree(info);
345 }
346 return 0;
347}
348
349#ifdef CONFIG_HVC_XEN_FRONTEND
350static struct xenbus_driver xencons_driver;
351
352static int xencons_remove(struct xenbus_device *dev)
353{
354 return xen_console_remove(dev_get_drvdata(&dev->dev));
355}
356
357static int xencons_connect_backend(struct xenbus_device *dev,
358 struct xencons_info *info)
359{
360 int ret, evtchn, devid, ref, irq;
361 struct xenbus_transaction xbt;
362 grant_ref_t gref_head;
363 unsigned long mfn;
364
365 ret = xenbus_alloc_evtchn(dev, &evtchn);
366 if (ret)
367 return ret;
368 info->evtchn = evtchn;
369 irq = bind_evtchn_to_irq(evtchn);
370 if (irq < 0)
371 return irq;
372 info->irq = irq;
373 devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
374 info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
375 irq, &domU_hvc_ops, 256);
376 if (IS_ERR(info->hvc))
377 return PTR_ERR(info->hvc);
378 if (xen_pv_domain())
379 mfn = virt_to_mfn(info->intf);
380 else
381 mfn = __pa(info->intf) >> PAGE_SHIFT;
382 ret = gnttab_alloc_grant_references(1, &gref_head);
383 if (ret < 0)
384 return ret;
385 info->gntref = gref_head;
386 ref = gnttab_claim_grant_reference(&gref_head);
387 if (ref < 0)
388 return ref;
389 gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
390 mfn, 0);
391
392 again:
393 ret = xenbus_transaction_start(&xbt);
394 if (ret) {
395 xenbus_dev_fatal(dev, ret, "starting transaction");
396 return ret;
397 }
398 ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref);
399 if (ret)
400 goto error_xenbus;
401 ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
402 evtchn);
403 if (ret)
404 goto error_xenbus;
405 ret = xenbus_printf(xbt, dev->nodename, "type", "ioemu");
406 if (ret)
407 goto error_xenbus;
408 ret = xenbus_transaction_end(xbt, 0);
409 if (ret) {
410 if (ret == -EAGAIN)
411 goto again;
412 xenbus_dev_fatal(dev, ret, "completing transaction");
413 return ret;
414 }
415
416 xenbus_switch_state(dev, XenbusStateInitialised);
417 return 0;
418
419 error_xenbus:
420 xenbus_transaction_end(xbt, 1);
421 xenbus_dev_fatal(dev, ret, "writing xenstore");
422 return ret;
423}
424
425static int __devinit xencons_probe(struct xenbus_device *dev,
426 const struct xenbus_device_id *id)
427{
428 int ret, devid;
429 struct xencons_info *info;
430
431 devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
432 if (devid == 0)
433 return -ENODEV;
434
435 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
436 if (!info)
437 return -ENOMEM;
438 dev_set_drvdata(&dev->dev, info);
439 info->xbdev = dev;
440 info->vtermno = xenbus_devid_to_vtermno(devid);
441 info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
442 if (!info->intf)
443 goto error_nomem;
444
445 ret = xencons_connect_backend(dev, info);
446 if (ret < 0)
447 goto error;
448 spin_lock(&xencons_lock);
449 list_add_tail(&info->list, &xenconsoles);
450 spin_unlock(&xencons_lock);
451
452 return 0;
453
454 error_nomem:
455 ret = -ENOMEM;
456 xenbus_dev_fatal(dev, ret, "allocating device memory");
457 error:
458 xencons_disconnect_backend(info);
459 xencons_free(info);
460 return ret;
461}
462
463static int xencons_resume(struct xenbus_device *dev)
464{
465 struct xencons_info *info = dev_get_drvdata(&dev->dev);
466
467 xencons_disconnect_backend(info);
468 memset(info->intf, 0, PAGE_SIZE);
469 return xencons_connect_backend(dev, info);
470}
471
472static void xencons_backend_changed(struct xenbus_device *dev,
473 enum xenbus_state backend_state)
474{
475 switch (backend_state) {
476 case XenbusStateReconfiguring:
477 case XenbusStateReconfigured:
478 case XenbusStateInitialising:
479 case XenbusStateInitialised:
480 case XenbusStateUnknown:
481 break;
482
483 case XenbusStateInitWait:
484 break;
485
486 case XenbusStateConnected:
487 xenbus_switch_state(dev, XenbusStateConnected);
488 break;
489
490 case XenbusStateClosed:
491 if (dev->state == XenbusStateClosed)
492 break;
493
494 case XenbusStateClosing:
495 xenbus_frontend_closed(dev);
496 break;
497 }
498}
499
500static const struct xenbus_device_id xencons_ids[] = {
501 { "console" },
502 { "" }
503};
504
505
506static DEFINE_XENBUS_DRIVER(xencons, "xenconsole",
507 .probe = xencons_probe,
508 .remove = xencons_remove,
509 .resume = xencons_resume,
510 .otherend_changed = xencons_backend_changed,
511);
512#endif
513
514static int __init xen_hvc_init(void)
515{
516 int r;
517 struct xencons_info *info;
518 const struct hv_ops *ops;
519
520 if (!xen_domain())
521 return -ENODEV;
522
523 if (xen_initial_domain()) {
524 ops = &dom0_hvc_ops;
525 r = xen_initial_domain_console_init();
526 if (r < 0)
527 return r;
528 info = vtermno_to_xencons(HVC_COOKIE);
529 } else {
530 ops = &domU_hvc_ops;
531 if (xen_hvm_domain())
532 r = xen_hvm_console_init();
533 else
534 r = xen_pv_console_init();
535 if (r < 0)
536 return r;
537
538 info = vtermno_to_xencons(HVC_COOKIE);
539 info->irq = bind_evtchn_to_irq(info->evtchn);
540 }
541 if (info->irq < 0)
542 info->irq = 0;
543 else
544 irq_set_noprobe(info->irq);
545
546 info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
547 if (IS_ERR(info->hvc)) {
548 r = PTR_ERR(info->hvc);
549 spin_lock(&xencons_lock);
550 list_del(&info->list);
551 spin_unlock(&xencons_lock);
552 if (info->irq)
553 unbind_from_irqhandler(info->irq, NULL);
554 kfree(info);
555 return r;
556 }
557
558 r = 0;
559#ifdef CONFIG_HVC_XEN_FRONTEND
560 r = xenbus_register_frontend(&xencons_driver);
561#endif
562 return r;
563}
564
565static void __exit xen_hvc_fini(void)
566{
567 struct xencons_info *entry, *next;
568
569 if (list_empty(&xenconsoles))
570 return;
571
572 list_for_each_entry_safe(entry, next, &xenconsoles, list) {
573 xen_console_remove(entry);
574 }
575}
576
577static int xen_cons_init(void)
578{
579 const struct hv_ops *ops;
580
581 if (!xen_domain())
582 return 0;
583
584 if (xen_initial_domain())
585 ops = &dom0_hvc_ops;
586 else {
587 int r;
588 ops = &domU_hvc_ops;
589
590 if (xen_hvm_domain())
591 r = xen_hvm_console_init();
592 else
593 r = xen_pv_console_init();
594 if (r < 0)
595 return r;
596 }
597
598 hvc_instantiate(HVC_COOKIE, 0, ops);
599 return 0;
600}
601
602
603module_init(xen_hvc_init);
604module_exit(xen_hvc_fini);
605console_initcall(xen_cons_init);
606
607#ifdef CONFIG_EARLY_PRINTK
608static void xenboot_write_console(struct console *console, const char *string,
609 unsigned len)
610{
611 unsigned int linelen, off = 0;
612 const char *pos;
613
614 if (!xen_pv_domain())
615 return;
616
617 dom0_write_console(0, string, len);
618
619 if (xen_initial_domain())
620 return;
621
622 domU_write_console(0, "(early) ", 8);
623 while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
624 linelen = pos-string+off;
625 if (off + linelen > len)
626 break;
627 domU_write_console(0, string+off, linelen);
628 domU_write_console(0, "\r\n", 2);
629 off += linelen + 1;
630 }
631 if (off < len)
632 domU_write_console(0, string+off, len-off);
633}
634
635struct console xenboot_console = {
636 .name = "xenboot",
637 .write = xenboot_write_console,
638 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
639};
640#endif
641
642void xen_raw_console_write(const char *str)
643{
644 dom0_write_console(0, str, strlen(str));
645}
646
647void xen_raw_printk(const char *fmt, ...)
648{
649 static char buf[512];
650 va_list ap;
651
652 va_start(ap, fmt);
653 vsnprintf(buf, sizeof(buf), fmt, ap);
654 va_end(ap);
655
656 xen_raw_console_write(buf);
657}
658