1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * xen console driver interface to hvc_console.c |
4 | * |
5 | * (c) 2007 Gerd Hoffmann <kraxel@suse.de> |
6 | */ |
7 | |
8 | #include <linux/console.h> |
9 | #include <linux/delay.h> |
10 | #include <linux/err.h> |
11 | #include <linux/irq.h> |
12 | #include <linux/init.h> |
13 | #include <linux/types.h> |
14 | #include <linux/list.h> |
15 | #include <linux/serial_core.h> |
16 | |
17 | #include <asm/io.h> |
18 | #include <asm/xen/hypervisor.h> |
19 | |
20 | #include <xen/xen.h> |
21 | #include <xen/interface/xen.h> |
22 | #include <xen/hvm.h> |
23 | #include <xen/grant_table.h> |
24 | #include <xen/page.h> |
25 | #include <xen/events.h> |
26 | #include <xen/interface/io/console.h> |
27 | #include <xen/interface/sched.h> |
28 | #include <xen/hvc-console.h> |
29 | #include <xen/xenbus.h> |
30 | |
31 | #include "hvc_console.h" |
32 | |
33 | #define HVC_COOKIE 0x58656e /* "Xen" in hex */ |
34 | |
35 | struct xencons_info { |
36 | struct list_head list; |
37 | struct xenbus_device *xbdev; |
38 | struct xencons_interface *intf; |
39 | unsigned int evtchn; |
40 | XENCONS_RING_IDX out_cons; |
41 | unsigned int out_cons_same; |
42 | struct hvc_struct *hvc; |
43 | int irq; |
44 | int vtermno; |
45 | grant_ref_t gntref; |
46 | spinlock_t ring_lock; |
47 | }; |
48 | |
49 | static LIST_HEAD(xenconsoles); |
50 | static DEFINE_SPINLOCK(xencons_lock); |
51 | |
52 | /* ------------------------------------------------------------------ */ |
53 | |
54 | static struct xencons_info *vtermno_to_xencons(int vtermno) |
55 | { |
56 | struct xencons_info *entry, *ret = NULL; |
57 | unsigned long flags; |
58 | |
59 | spin_lock_irqsave(&xencons_lock, flags); |
60 | if (list_empty(head: &xenconsoles)) { |
61 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
62 | return NULL; |
63 | } |
64 | |
65 | list_for_each_entry(entry, &xenconsoles, list) { |
66 | if (entry->vtermno == vtermno) { |
67 | ret = entry; |
68 | break; |
69 | } |
70 | } |
71 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
72 | |
73 | return ret; |
74 | } |
75 | |
76 | static inline int xenbus_devid_to_vtermno(int devid) |
77 | { |
78 | return devid + HVC_COOKIE; |
79 | } |
80 | |
81 | static inline void notify_daemon(struct xencons_info *cons) |
82 | { |
83 | /* Use evtchn: this is called early, before irq is set up. */ |
84 | notify_remote_via_evtchn(port: cons->evtchn); |
85 | } |
86 | |
87 | static ssize_t __write_console(struct xencons_info *xencons, |
88 | const u8 *data, size_t len) |
89 | { |
90 | XENCONS_RING_IDX cons, prod; |
91 | struct xencons_interface *intf = xencons->intf; |
92 | unsigned long flags; |
93 | size_t sent = 0; |
94 | |
95 | spin_lock_irqsave(&xencons->ring_lock, flags); |
96 | cons = intf->out_cons; |
97 | prod = intf->out_prod; |
98 | mb(); /* update queue values before going on */ |
99 | |
100 | if ((prod - cons) > sizeof(intf->out)) { |
101 | spin_unlock_irqrestore(lock: &xencons->ring_lock, flags); |
102 | pr_err_once("xencons: Illegal ring page indices" ); |
103 | return -EINVAL; |
104 | } |
105 | |
106 | while ((sent < len) && ((prod - cons) < sizeof(intf->out))) |
107 | intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++]; |
108 | |
109 | wmb(); /* write ring before updating pointer */ |
110 | intf->out_prod = prod; |
111 | spin_unlock_irqrestore(lock: &xencons->ring_lock, flags); |
112 | |
113 | if (sent) |
114 | notify_daemon(cons: xencons); |
115 | return sent; |
116 | } |
117 | |
118 | static ssize_t domU_write_console(uint32_t vtermno, const u8 *data, size_t len) |
119 | { |
120 | struct xencons_info *cons = vtermno_to_xencons(vtermno); |
121 | size_t ret = len; |
122 | |
123 | if (cons == NULL) |
124 | return -EINVAL; |
125 | |
126 | /* |
127 | * Make sure the whole buffer is emitted, polling if |
128 | * necessary. We don't ever want to rely on the hvc daemon |
129 | * because the most interesting console output is when the |
130 | * kernel is crippled. |
131 | */ |
132 | while (len) { |
133 | ssize_t sent = __write_console(xencons: cons, data, len); |
134 | |
135 | if (sent < 0) |
136 | return sent; |
137 | |
138 | data += sent; |
139 | len -= sent; |
140 | |
141 | if (unlikely(len)) |
142 | HYPERVISOR_sched_op(SCHEDOP_yield, NULL); |
143 | } |
144 | |
145 | return ret; |
146 | } |
147 | |
148 | static ssize_t domU_read_console(uint32_t vtermno, u8 *buf, size_t len) |
149 | { |
150 | struct xencons_interface *intf; |
151 | XENCONS_RING_IDX cons, prod; |
152 | struct xencons_info *xencons = vtermno_to_xencons(vtermno); |
153 | unsigned int eoiflag = 0; |
154 | unsigned long flags; |
155 | size_t recv = 0; |
156 | |
157 | if (xencons == NULL) |
158 | return -EINVAL; |
159 | intf = xencons->intf; |
160 | |
161 | spin_lock_irqsave(&xencons->ring_lock, flags); |
162 | cons = intf->in_cons; |
163 | prod = intf->in_prod; |
164 | mb(); /* get pointers before reading ring */ |
165 | |
166 | if ((prod - cons) > sizeof(intf->in)) { |
167 | spin_unlock_irqrestore(lock: &xencons->ring_lock, flags); |
168 | pr_err_once("xencons: Illegal ring page indices" ); |
169 | return -EINVAL; |
170 | } |
171 | |
172 | while (cons != prod && recv < len) |
173 | buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)]; |
174 | |
175 | mb(); /* read ring before consuming */ |
176 | intf->in_cons = cons; |
177 | |
178 | /* |
179 | * When to mark interrupt having been spurious: |
180 | * - there was no new data to be read, and |
181 | * - the backend did not consume some output bytes, and |
182 | * - the previous round with no read data didn't see consumed bytes |
183 | * (we might have a race with an interrupt being in flight while |
184 | * updating xencons->out_cons, so account for that by allowing one |
185 | * round without any visible reason) |
186 | */ |
187 | if (intf->out_cons != xencons->out_cons) { |
188 | xencons->out_cons = intf->out_cons; |
189 | xencons->out_cons_same = 0; |
190 | } |
191 | if (!recv && xencons->out_cons_same++ > 1) { |
192 | eoiflag = XEN_EOI_FLAG_SPURIOUS; |
193 | } |
194 | spin_unlock_irqrestore(lock: &xencons->ring_lock, flags); |
195 | |
196 | if (recv) { |
197 | notify_daemon(cons: xencons); |
198 | } |
199 | |
200 | xen_irq_lateeoi(irq: xencons->irq, eoi_flags: eoiflag); |
201 | |
202 | return recv; |
203 | } |
204 | |
205 | static const struct hv_ops domU_hvc_ops = { |
206 | .get_chars = domU_read_console, |
207 | .put_chars = domU_write_console, |
208 | .notifier_add = notifier_add_irq, |
209 | .notifier_del = notifier_del_irq, |
210 | .notifier_hangup = notifier_hangup_irq, |
211 | }; |
212 | |
213 | static ssize_t dom0_read_console(uint32_t vtermno, u8 *buf, size_t len) |
214 | { |
215 | return HYPERVISOR_console_io(CONSOLEIO_read, count: len, str: buf); |
216 | } |
217 | |
218 | /* |
219 | * Either for a dom0 to write to the system console, or a domU with a |
220 | * debug version of Xen |
221 | */ |
222 | static ssize_t dom0_write_console(uint32_t vtermno, const u8 *str, size_t len) |
223 | { |
224 | int rc = HYPERVISOR_console_io(CONSOLEIO_write, count: len, str: (u8 *)str); |
225 | if (rc < 0) |
226 | return rc; |
227 | |
228 | return len; |
229 | } |
230 | |
231 | static const struct hv_ops dom0_hvc_ops = { |
232 | .get_chars = dom0_read_console, |
233 | .put_chars = dom0_write_console, |
234 | .notifier_add = notifier_add_irq, |
235 | .notifier_del = notifier_del_irq, |
236 | .notifier_hangup = notifier_hangup_irq, |
237 | }; |
238 | |
239 | static int xen_hvm_console_init(void) |
240 | { |
241 | int r; |
242 | uint64_t v = 0; |
243 | unsigned long gfn, flags; |
244 | struct xencons_info *info; |
245 | |
246 | if (!xen_hvm_domain()) |
247 | return -ENODEV; |
248 | |
249 | info = vtermno_to_xencons(HVC_COOKIE); |
250 | if (!info) { |
251 | info = kzalloc(size: sizeof(struct xencons_info), GFP_KERNEL); |
252 | if (!info) |
253 | return -ENOMEM; |
254 | spin_lock_init(&info->ring_lock); |
255 | } else if (info->intf != NULL) { |
256 | /* already configured */ |
257 | return 0; |
258 | } |
259 | /* |
260 | * If the toolstack (or the hypervisor) hasn't set these values, the |
261 | * default value is 0. Even though gfn = 0 and evtchn = 0 are |
262 | * theoretically correct values, in practice they never are and they |
263 | * mean that a legacy toolstack hasn't initialized the pv console correctly. |
264 | */ |
265 | r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, value: &v); |
266 | if (r < 0 || v == 0) |
267 | goto err; |
268 | info->evtchn = v; |
269 | v = 0; |
270 | r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, value: &v); |
271 | if (r < 0 || v == 0) |
272 | goto err; |
273 | gfn = v; |
274 | info->intf = memremap(offset: gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, flags: MEMREMAP_WB); |
275 | if (info->intf == NULL) |
276 | goto err; |
277 | info->vtermno = HVC_COOKIE; |
278 | |
279 | spin_lock_irqsave(&xencons_lock, flags); |
280 | list_add_tail(new: &info->list, head: &xenconsoles); |
281 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
282 | |
283 | return 0; |
284 | err: |
285 | kfree(objp: info); |
286 | return -ENODEV; |
287 | } |
288 | |
289 | static int xencons_info_pv_init(struct xencons_info *info, int vtermno) |
290 | { |
291 | spin_lock_init(&info->ring_lock); |
292 | info->evtchn = xen_start_info->console.domU.evtchn; |
293 | /* GFN == MFN for PV guest */ |
294 | info->intf = gfn_to_virt(xen_start_info->console.domU.mfn); |
295 | info->vtermno = vtermno; |
296 | |
297 | list_add_tail(new: &info->list, head: &xenconsoles); |
298 | |
299 | return 0; |
300 | } |
301 | |
302 | static int xen_pv_console_init(void) |
303 | { |
304 | struct xencons_info *info; |
305 | unsigned long flags; |
306 | |
307 | if (!xen_pv_domain()) |
308 | return -ENODEV; |
309 | |
310 | if (!xen_start_info->console.domU.evtchn) |
311 | return -ENODEV; |
312 | |
313 | info = vtermno_to_xencons(HVC_COOKIE); |
314 | if (!info) { |
315 | info = kzalloc(size: sizeof(struct xencons_info), GFP_KERNEL); |
316 | if (!info) |
317 | return -ENOMEM; |
318 | } else if (info->intf != NULL) { |
319 | /* already configured */ |
320 | return 0; |
321 | } |
322 | spin_lock_irqsave(&xencons_lock, flags); |
323 | xencons_info_pv_init(info, HVC_COOKIE); |
324 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
325 | |
326 | return 0; |
327 | } |
328 | |
329 | static int xen_initial_domain_console_init(void) |
330 | { |
331 | struct xencons_info *info; |
332 | unsigned long flags; |
333 | |
334 | if (!xen_initial_domain()) |
335 | return -ENODEV; |
336 | |
337 | info = vtermno_to_xencons(HVC_COOKIE); |
338 | if (!info) { |
339 | info = kzalloc(size: sizeof(struct xencons_info), GFP_KERNEL); |
340 | if (!info) |
341 | return -ENOMEM; |
342 | spin_lock_init(&info->ring_lock); |
343 | } |
344 | |
345 | info->irq = bind_virq_to_irq(VIRQ_CONSOLE, cpu: 0, percpu: false); |
346 | info->vtermno = HVC_COOKIE; |
347 | |
348 | spin_lock_irqsave(&xencons_lock, flags); |
349 | list_add_tail(new: &info->list, head: &xenconsoles); |
350 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
351 | |
352 | return 0; |
353 | } |
354 | |
355 | static void xen_console_update_evtchn(struct xencons_info *info) |
356 | { |
357 | if (xen_hvm_domain()) { |
358 | uint64_t v = 0; |
359 | int err; |
360 | |
361 | err = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, value: &v); |
362 | if (!err && v) |
363 | info->evtchn = v; |
364 | } else |
365 | info->evtchn = xen_start_info->console.domU.evtchn; |
366 | } |
367 | |
368 | void xen_console_resume(void) |
369 | { |
370 | struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE); |
371 | if (info != NULL && info->irq) { |
372 | if (!xen_initial_domain()) |
373 | xen_console_update_evtchn(info); |
374 | rebind_evtchn_irq(evtchn: info->evtchn, irq: info->irq); |
375 | } |
376 | } |
377 | |
378 | #ifdef CONFIG_HVC_XEN_FRONTEND |
379 | static void xencons_disconnect_backend(struct xencons_info *info) |
380 | { |
381 | if (info->hvc != NULL) |
382 | hvc_remove(hp: info->hvc); |
383 | info->hvc = NULL; |
384 | if (info->irq > 0) { |
385 | evtchn_put(evtchn: info->evtchn); |
386 | info->irq = 0; |
387 | info->evtchn = 0; |
388 | } |
389 | /* evtchn_put() will also close it so this is only an error path */ |
390 | if (info->evtchn > 0) |
391 | xenbus_free_evtchn(dev: info->xbdev, port: info->evtchn); |
392 | info->evtchn = 0; |
393 | if (info->gntref > 0) |
394 | gnttab_free_grant_references(head: info->gntref); |
395 | info->gntref = 0; |
396 | } |
397 | |
398 | static void xencons_free(struct xencons_info *info) |
399 | { |
400 | free_page((unsigned long)info->intf); |
401 | info->intf = NULL; |
402 | info->vtermno = 0; |
403 | kfree(objp: info); |
404 | } |
405 | |
406 | static int xen_console_remove(struct xencons_info *info) |
407 | { |
408 | unsigned long flags; |
409 | |
410 | xencons_disconnect_backend(info); |
411 | spin_lock_irqsave(&xencons_lock, flags); |
412 | list_del(entry: &info->list); |
413 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
414 | if (info->xbdev != NULL) |
415 | xencons_free(info); |
416 | else { |
417 | if (xen_hvm_domain()) |
418 | iounmap(addr: info->intf); |
419 | kfree(objp: info); |
420 | } |
421 | return 0; |
422 | } |
423 | |
424 | static void xencons_remove(struct xenbus_device *dev) |
425 | { |
426 | xen_console_remove(info: dev_get_drvdata(dev: &dev->dev)); |
427 | } |
428 | |
429 | static int xencons_connect_backend(struct xenbus_device *dev, |
430 | struct xencons_info *info) |
431 | { |
432 | int ret, evtchn, devid, ref, irq; |
433 | struct xenbus_transaction xbt; |
434 | grant_ref_t gref_head; |
435 | |
436 | ret = xenbus_alloc_evtchn(dev, port: &evtchn); |
437 | if (ret) |
438 | return ret; |
439 | info->evtchn = evtchn; |
440 | irq = bind_evtchn_to_irq_lateeoi(evtchn); |
441 | if (irq < 0) |
442 | return irq; |
443 | info->irq = irq; |
444 | devid = dev->nodename[strlen(dev->nodename) - 1] - '0'; |
445 | info->hvc = hvc_alloc(vtermno: xenbus_devid_to_vtermno(devid), |
446 | data: irq, ops: &domU_hvc_ops, outbuf_size: 256); |
447 | if (IS_ERR(ptr: info->hvc)) |
448 | return PTR_ERR(ptr: info->hvc); |
449 | ret = gnttab_alloc_grant_references(count: 1, pprivate_head: &gref_head); |
450 | if (ret < 0) |
451 | return ret; |
452 | info->gntref = gref_head; |
453 | ref = gnttab_claim_grant_reference(pprivate_head: &gref_head); |
454 | if (ref < 0) |
455 | return ref; |
456 | gnttab_grant_foreign_access_ref(ref, domid: info->xbdev->otherend_id, |
457 | virt_to_gfn(info->intf), readonly: 0); |
458 | |
459 | again: |
460 | ret = xenbus_transaction_start(t: &xbt); |
461 | if (ret) { |
462 | xenbus_dev_fatal(dev, err: ret, fmt: "starting transaction" ); |
463 | return ret; |
464 | } |
465 | ret = xenbus_printf(t: xbt, dir: dev->nodename, node: "ring-ref" , fmt: "%d" , ref); |
466 | if (ret) |
467 | goto error_xenbus; |
468 | ret = xenbus_printf(t: xbt, dir: dev->nodename, node: "port" , fmt: "%u" , |
469 | evtchn); |
470 | if (ret) |
471 | goto error_xenbus; |
472 | ret = xenbus_transaction_end(t: xbt, abort: 0); |
473 | if (ret) { |
474 | if (ret == -EAGAIN) |
475 | goto again; |
476 | xenbus_dev_fatal(dev, err: ret, fmt: "completing transaction" ); |
477 | return ret; |
478 | } |
479 | |
480 | xenbus_switch_state(dev, new_state: XenbusStateInitialised); |
481 | return 0; |
482 | |
483 | error_xenbus: |
484 | xenbus_transaction_end(t: xbt, abort: 1); |
485 | xenbus_dev_fatal(dev, err: ret, fmt: "writing xenstore" ); |
486 | return ret; |
487 | } |
488 | |
489 | static int xencons_probe(struct xenbus_device *dev, |
490 | const struct xenbus_device_id *id) |
491 | { |
492 | int ret, devid; |
493 | struct xencons_info *info; |
494 | unsigned long flags; |
495 | |
496 | devid = dev->nodename[strlen(dev->nodename) - 1] - '0'; |
497 | if (devid == 0) |
498 | return -ENODEV; |
499 | |
500 | info = kzalloc(size: sizeof(struct xencons_info), GFP_KERNEL); |
501 | if (!info) |
502 | return -ENOMEM; |
503 | spin_lock_init(&info->ring_lock); |
504 | dev_set_drvdata(dev: &dev->dev, data: info); |
505 | info->xbdev = dev; |
506 | info->vtermno = xenbus_devid_to_vtermno(devid); |
507 | info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
508 | if (!info->intf) |
509 | goto error_nomem; |
510 | |
511 | ret = xencons_connect_backend(dev, info); |
512 | if (ret < 0) |
513 | goto error; |
514 | spin_lock_irqsave(&xencons_lock, flags); |
515 | list_add_tail(new: &info->list, head: &xenconsoles); |
516 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
517 | |
518 | return 0; |
519 | |
520 | error_nomem: |
521 | ret = -ENOMEM; |
522 | xenbus_dev_fatal(dev, err: ret, fmt: "allocating device memory" ); |
523 | error: |
524 | xencons_disconnect_backend(info); |
525 | xencons_free(info); |
526 | return ret; |
527 | } |
528 | |
529 | static int xencons_resume(struct xenbus_device *dev) |
530 | { |
531 | struct xencons_info *info = dev_get_drvdata(dev: &dev->dev); |
532 | |
533 | xencons_disconnect_backend(info); |
534 | memset(info->intf, 0, XEN_PAGE_SIZE); |
535 | return xencons_connect_backend(dev, info); |
536 | } |
537 | |
538 | static void xencons_backend_changed(struct xenbus_device *dev, |
539 | enum xenbus_state backend_state) |
540 | { |
541 | switch (backend_state) { |
542 | case XenbusStateReconfiguring: |
543 | case XenbusStateReconfigured: |
544 | case XenbusStateInitialising: |
545 | case XenbusStateInitialised: |
546 | case XenbusStateUnknown: |
547 | break; |
548 | |
549 | case XenbusStateInitWait: |
550 | break; |
551 | |
552 | case XenbusStateConnected: |
553 | xenbus_switch_state(dev, new_state: XenbusStateConnected); |
554 | break; |
555 | |
556 | case XenbusStateClosed: |
557 | if (dev->state == XenbusStateClosed) |
558 | break; |
559 | fallthrough; /* Missed the backend's CLOSING state */ |
560 | case XenbusStateClosing: { |
561 | struct xencons_info *info = dev_get_drvdata(dev: &dev->dev);; |
562 | |
563 | /* |
564 | * Don't tear down the evtchn and grant ref before the other |
565 | * end has disconnected, but do stop userspace from trying |
566 | * to use the device before we allow the backend to close. |
567 | */ |
568 | if (info->hvc) { |
569 | hvc_remove(hp: info->hvc); |
570 | info->hvc = NULL; |
571 | } |
572 | |
573 | xenbus_frontend_closed(dev); |
574 | break; |
575 | } |
576 | } |
577 | } |
578 | |
579 | static const struct xenbus_device_id xencons_ids[] = { |
580 | { "console" }, |
581 | { "" } |
582 | }; |
583 | |
584 | static struct xenbus_driver xencons_driver = { |
585 | .name = "xenconsole" , |
586 | .ids = xencons_ids, |
587 | .probe = xencons_probe, |
588 | .remove = xencons_remove, |
589 | .resume = xencons_resume, |
590 | .otherend_changed = xencons_backend_changed, |
591 | .not_essential = true, |
592 | }; |
593 | #endif /* CONFIG_HVC_XEN_FRONTEND */ |
594 | |
595 | static int __init xen_hvc_init(void) |
596 | { |
597 | int r; |
598 | struct xencons_info *info; |
599 | const struct hv_ops *ops; |
600 | |
601 | if (!xen_domain()) |
602 | return -ENODEV; |
603 | |
604 | if (xen_initial_domain()) { |
605 | ops = &dom0_hvc_ops; |
606 | r = xen_initial_domain_console_init(); |
607 | if (r < 0) |
608 | goto register_fe; |
609 | info = vtermno_to_xencons(HVC_COOKIE); |
610 | } else { |
611 | ops = &domU_hvc_ops; |
612 | if (xen_hvm_domain()) |
613 | r = xen_hvm_console_init(); |
614 | else |
615 | r = xen_pv_console_init(); |
616 | if (r < 0) |
617 | goto register_fe; |
618 | |
619 | info = vtermno_to_xencons(HVC_COOKIE); |
620 | info->irq = bind_evtchn_to_irq_lateeoi(evtchn: info->evtchn); |
621 | } |
622 | if (info->irq < 0) |
623 | info->irq = 0; /* NO_IRQ */ |
624 | else |
625 | irq_set_noprobe(irq: info->irq); |
626 | |
627 | info->hvc = hvc_alloc(HVC_COOKIE, data: info->irq, ops, outbuf_size: 256); |
628 | if (IS_ERR(ptr: info->hvc)) { |
629 | unsigned long flags; |
630 | |
631 | r = PTR_ERR(ptr: info->hvc); |
632 | spin_lock_irqsave(&xencons_lock, flags); |
633 | list_del(entry: &info->list); |
634 | spin_unlock_irqrestore(lock: &xencons_lock, flags); |
635 | if (info->irq) |
636 | evtchn_put(evtchn: info->evtchn); |
637 | kfree(objp: info); |
638 | return r; |
639 | } |
640 | |
641 | r = 0; |
642 | register_fe: |
643 | #ifdef CONFIG_HVC_XEN_FRONTEND |
644 | r = xenbus_register_frontend(&xencons_driver); |
645 | #endif |
646 | return r; |
647 | } |
648 | device_initcall(xen_hvc_init); |
649 | |
650 | static int xen_cons_init(void) |
651 | { |
652 | const struct hv_ops *ops; |
653 | |
654 | if (!xen_domain()) |
655 | return 0; |
656 | |
657 | if (xen_initial_domain()) |
658 | ops = &dom0_hvc_ops; |
659 | else { |
660 | int r; |
661 | ops = &domU_hvc_ops; |
662 | |
663 | if (xen_hvm_domain()) |
664 | r = xen_hvm_console_init(); |
665 | else |
666 | r = xen_pv_console_init(); |
667 | if (r < 0) |
668 | return r; |
669 | } |
670 | |
671 | hvc_instantiate(HVC_COOKIE, index: 0, ops); |
672 | return 0; |
673 | } |
674 | console_initcall(xen_cons_init); |
675 | |
676 | #ifdef CONFIG_X86 |
677 | static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) |
678 | { |
679 | if (xen_cpuid_base()) |
680 | outsb(port: 0xe9, addr: str, count: len); |
681 | } |
682 | #else |
683 | static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) { } |
684 | #endif |
685 | |
686 | #ifdef CONFIG_EARLY_PRINTK |
687 | static int __init xenboot_console_setup(struct console *console, char *string) |
688 | { |
689 | static struct xencons_info xenboot; |
690 | |
691 | if (xen_initial_domain() || !xen_pv_domain()) |
692 | return 0; |
693 | |
694 | return xencons_info_pv_init(info: &xenboot, vtermno: 0); |
695 | } |
696 | |
697 | static void xenboot_write_console(struct console *console, const char *string, |
698 | unsigned len) |
699 | { |
700 | unsigned int linelen, off = 0; |
701 | const char *pos; |
702 | |
703 | if (dom0_write_console(vtermno: 0, str: string, len) >= 0) |
704 | return; |
705 | |
706 | if (!xen_pv_domain()) { |
707 | xen_hvm_early_write(vtermno: 0, str: string, len); |
708 | return; |
709 | } |
710 | |
711 | if (domU_write_console(vtermno: 0, data: "(early) " , len: 8) < 0) |
712 | return; |
713 | while (off < len && NULL != (pos = strchr(string+off, '\n'))) { |
714 | linelen = pos-string+off; |
715 | if (off + linelen > len) |
716 | break; |
717 | domU_write_console(vtermno: 0, data: string+off, len: linelen); |
718 | domU_write_console(vtermno: 0, data: "\r\n" , len: 2); |
719 | off += linelen + 1; |
720 | } |
721 | if (off < len) |
722 | domU_write_console(vtermno: 0, data: string+off, len: len-off); |
723 | } |
724 | |
725 | struct console xenboot_console = { |
726 | .name = "xenboot" , |
727 | .write = xenboot_write_console, |
728 | .setup = xenboot_console_setup, |
729 | .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME, |
730 | .index = -1, |
731 | }; |
732 | #endif /* CONFIG_EARLY_PRINTK */ |
733 | |
734 | void xen_raw_console_write(const char *str) |
735 | { |
736 | ssize_t len = strlen(str); |
737 | int rc = 0; |
738 | |
739 | if (xen_domain()) { |
740 | rc = dom0_write_console(vtermno: 0, str, len); |
741 | if (rc != -ENOSYS || !xen_hvm_domain()) |
742 | return; |
743 | } |
744 | xen_hvm_early_write(vtermno: 0, str, len); |
745 | } |
746 | |
747 | void xen_raw_printk(const char *fmt, ...) |
748 | { |
749 | static char buf[512]; |
750 | va_list ap; |
751 | |
752 | va_start(ap, fmt); |
753 | vsnprintf(buf, size: sizeof(buf), fmt, args: ap); |
754 | va_end(ap); |
755 | |
756 | xen_raw_console_write(str: buf); |
757 | } |
758 | |
759 | static void xenboot_earlycon_write(struct console *console, |
760 | const char *string, |
761 | unsigned len) |
762 | { |
763 | dom0_write_console(vtermno: 0, str: string, len); |
764 | } |
765 | |
766 | static int __init xenboot_earlycon_setup(struct earlycon_device *device, |
767 | const char *opt) |
768 | { |
769 | device->con->write = xenboot_earlycon_write; |
770 | return 0; |
771 | } |
772 | EARLYCON_DECLARE(xenboot, xenboot_earlycon_setup); |
773 | |