2 * xen console driver interface to hvc_console.c
4 * (c) 2007 Gerd Hoffmann <kraxel@suse.de>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <linux/console.h>
22 #include <linux/delay.h>
23 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/types.h>
26 #include <linux/list.h>
29 #include <asm/xen/hypervisor.h>
32 #include <xen/interface/xen.h>
34 #include <xen/grant_table.h>
36 #include <xen/events.h>
37 #include <xen/interface/io/console.h>
38 #include <xen/hvc-console.h>
39 #include <xen/xenbus.h>
41 #include "hvc_console.h"
43 #define HVC_COOKIE 0x58656e /* "Xen" in hex */
46 struct list_head list;
47 struct xenbus_device *xbdev;
48 struct xencons_interface *intf;
50 struct hvc_struct *hvc;
56 static LIST_HEAD(xenconsoles);
57 static DEFINE_SPINLOCK(xencons_lock);
59 /* ------------------------------------------------------------------ */
61 static struct xencons_info *vtermno_to_xencons(int vtermno)
63 struct xencons_info *entry, *n, *ret = NULL;
65 if (list_empty(&xenconsoles))
68 list_for_each_entry_safe(entry, n, &xenconsoles, list) {
69 if (entry->vtermno == vtermno) {
78 static inline int xenbus_devid_to_vtermno(int devid)
80 return devid + HVC_COOKIE;
83 static inline void notify_daemon(struct xencons_info *cons)
85 /* Use evtchn: this is called early, before irq is set up. */
86 notify_remote_via_evtchn(cons->evtchn);
89 static int __write_console(struct xencons_info *xencons,
90 const char *data, int len)
92 XENCONS_RING_IDX cons, prod;
93 struct xencons_interface *intf = xencons->intf;
96 cons = intf->out_cons;
97 prod = intf->out_prod;
98 mb(); /* update queue values before going on */
99 BUG_ON((prod - cons) > sizeof(intf->out));
101 while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
102 intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
104 wmb(); /* write ring before updating pointer */
105 intf->out_prod = prod;
108 notify_daemon(xencons);
112 static int domU_write_console(uint32_t vtermno, const char *data, int len)
115 struct xencons_info *cons = vtermno_to_xencons(vtermno);
120 * Make sure the whole buffer is emitted, polling if
121 * necessary. We don't ever want to rely on the hvc daemon
122 * because the most interesting console output is when the
123 * kernel is crippled.
126 int sent = __write_console(cons, data, len);
132 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
138 static int domU_read_console(uint32_t vtermno, char *buf, int len)
140 struct xencons_interface *intf;
141 XENCONS_RING_IDX cons, prod;
143 struct xencons_info *xencons = vtermno_to_xencons(vtermno);
146 intf = xencons->intf;
148 cons = intf->in_cons;
149 prod = intf->in_prod;
150 mb(); /* get pointers before reading ring */
151 BUG_ON((prod - cons) > sizeof(intf->in));
153 while (cons != prod && recv < len)
154 buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
156 mb(); /* read ring before consuming */
157 intf->in_cons = cons;
159 notify_daemon(xencons);
163 static struct hv_ops domU_hvc_ops = {
164 .get_chars = domU_read_console,
165 .put_chars = domU_write_console,
166 .notifier_add = notifier_add_irq,
167 .notifier_del = notifier_del_irq,
168 .notifier_hangup = notifier_hangup_irq,
171 static int dom0_read_console(uint32_t vtermno, char *buf, int len)
173 return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
177 * Either for a dom0 to write to the system console, or a domU with a
178 * debug version of Xen
180 static int dom0_write_console(uint32_t vtermno, const char *str, int len)
182 int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
189 static struct hv_ops dom0_hvc_ops = {
190 .get_chars = dom0_read_console,
191 .put_chars = dom0_write_console,
192 .notifier_add = notifier_add_irq,
193 .notifier_del = notifier_del_irq,
194 .notifier_hangup = notifier_hangup_irq,
197 static int xen_hvm_console_init(void)
202 struct xencons_info *info;
204 if (!xen_hvm_domain())
207 info = vtermno_to_xencons(HVC_COOKIE);
209 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
214 /* already configured */
215 if (info->intf != NULL)
218 r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
222 hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
226 info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
227 if (info->intf == NULL)
229 info->vtermno = HVC_COOKIE;
231 spin_lock(&xencons_lock);
232 list_add_tail(&info->list, &xenconsoles);
233 spin_unlock(&xencons_lock);
241 static int xen_pv_console_init(void)
243 struct xencons_info *info;
245 if (!xen_pv_domain())
248 if (!xen_start_info->console.domU.evtchn)
251 info = vtermno_to_xencons(HVC_COOKIE);
253 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
258 /* already configured */
259 if (info->intf != NULL)
262 info->evtchn = xen_start_info->console.domU.evtchn;
263 info->intf = mfn_to_virt(xen_start_info->console.domU.mfn);
264 info->vtermno = HVC_COOKIE;
266 spin_lock(&xencons_lock);
267 list_add_tail(&info->list, &xenconsoles);
268 spin_unlock(&xencons_lock);
273 static int xen_initial_domain_console_init(void)
275 struct xencons_info *info;
277 if (!xen_initial_domain())
280 info = vtermno_to_xencons(HVC_COOKIE);
282 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
287 info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
288 info->vtermno = HVC_COOKIE;
290 spin_lock(&xencons_lock);
291 list_add_tail(&info->list, &xenconsoles);
292 spin_unlock(&xencons_lock);
297 void xen_console_resume(void)
299 struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
300 if (info != NULL && info->irq)
301 rebind_evtchn_irq(info->evtchn, info->irq);
304 static void xencons_disconnect_backend(struct xencons_info *info)
307 unbind_from_irqhandler(info->irq, NULL);
309 if (info->evtchn > 0)
310 xenbus_free_evtchn(info->xbdev, info->evtchn);
312 if (info->gntref > 0)
313 gnttab_free_grant_references(info->gntref);
315 if (info->hvc != NULL)
316 hvc_remove(info->hvc);
320 static void xencons_free(struct xencons_info *info)
322 free_page((unsigned long)info->intf);
328 static int xen_console_remove(struct xencons_info *info)
330 xencons_disconnect_backend(info);
331 spin_lock(&xencons_lock);
332 list_del(&info->list);
333 spin_unlock(&xencons_lock);
334 if (info->xbdev != NULL)
337 if (xen_hvm_domain())
344 #ifdef CONFIG_HVC_XEN_FRONTEND
345 static struct xenbus_driver xencons_driver;
347 static int xencons_remove(struct xenbus_device *dev)
349 return xen_console_remove(dev_get_drvdata(&dev->dev));
352 static int xencons_connect_backend(struct xenbus_device *dev,
353 struct xencons_info *info)
355 int ret, evtchn, devid, ref, irq;
356 struct xenbus_transaction xbt;
357 grant_ref_t gref_head;
360 ret = xenbus_alloc_evtchn(dev, &evtchn);
363 info->evtchn = evtchn;
364 irq = bind_evtchn_to_irq(evtchn);
368 devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
369 info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
370 irq, &domU_hvc_ops, 256);
371 if (IS_ERR(info->hvc))
372 return PTR_ERR(info->hvc);
374 mfn = virt_to_mfn(info->intf);
376 mfn = __pa(info->intf) >> PAGE_SHIFT;
377 ret = gnttab_alloc_grant_references(1, &gref_head);
380 info->gntref = gref_head;
381 ref = gnttab_claim_grant_reference(&gref_head);
384 gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
388 ret = xenbus_transaction_start(&xbt);
390 xenbus_dev_fatal(dev, ret, "starting transaction");
393 ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref);
396 ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
400 ret = xenbus_printf(xbt, dev->nodename, "type", "ioemu");
403 ret = xenbus_transaction_end(xbt, 0);
407 xenbus_dev_fatal(dev, ret, "completing transaction");
411 xenbus_switch_state(dev, XenbusStateInitialised);
415 xenbus_transaction_end(xbt, 1);
416 xenbus_dev_fatal(dev, ret, "writing xenstore");
420 static int __devinit xencons_probe(struct xenbus_device *dev,
421 const struct xenbus_device_id *id)
424 struct xencons_info *info;
426 devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
430 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
433 dev_set_drvdata(&dev->dev, info);
435 info->vtermno = xenbus_devid_to_vtermno(devid);
436 info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
440 ret = xencons_connect_backend(dev, info);
443 spin_lock(&xencons_lock);
444 list_add_tail(&info->list, &xenconsoles);
445 spin_unlock(&xencons_lock);
451 xenbus_dev_fatal(dev, ret, "allocating device memory");
453 xencons_disconnect_backend(info);
458 static int xencons_resume(struct xenbus_device *dev)
460 struct xencons_info *info = dev_get_drvdata(&dev->dev);
462 xencons_disconnect_backend(info);
463 memset(info->intf, 0, PAGE_SIZE);
464 return xencons_connect_backend(dev, info);
467 static void xencons_backend_changed(struct xenbus_device *dev,
468 enum xenbus_state backend_state)
470 switch (backend_state) {
471 case XenbusStateReconfiguring:
472 case XenbusStateReconfigured:
473 case XenbusStateInitialising:
474 case XenbusStateInitialised:
475 case XenbusStateUnknown:
476 case XenbusStateClosed:
479 case XenbusStateInitWait:
482 case XenbusStateConnected:
483 xenbus_switch_state(dev, XenbusStateConnected);
486 case XenbusStateClosing:
487 xenbus_frontend_closed(dev);
492 static const struct xenbus_device_id xencons_ids[] = {
498 static DEFINE_XENBUS_DRIVER(xencons, "xenconsole",
499 .probe = xencons_probe,
500 .remove = xencons_remove,
501 .resume = xencons_resume,
502 .otherend_changed = xencons_backend_changed,
504 #endif /* CONFIG_HVC_XEN_FRONTEND */
506 static int __init xen_hvc_init(void)
509 struct xencons_info *info;
510 const struct hv_ops *ops;
515 if (xen_initial_domain()) {
517 r = xen_initial_domain_console_init();
520 info = vtermno_to_xencons(HVC_COOKIE);
523 if (xen_hvm_domain())
524 r = xen_hvm_console_init();
526 r = xen_pv_console_init();
530 info = vtermno_to_xencons(HVC_COOKIE);
531 info->irq = bind_evtchn_to_irq(info->evtchn);
534 info->irq = 0; /* NO_IRQ */
536 irq_set_noprobe(info->irq);
538 info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
539 if (IS_ERR(info->hvc)) {
540 r = PTR_ERR(info->hvc);
541 spin_lock(&xencons_lock);
542 list_del(&info->list);
543 spin_unlock(&xencons_lock);
545 unbind_from_irqhandler(info->irq, NULL);
551 #ifdef CONFIG_HVC_XEN_FRONTEND
552 r = xenbus_register_frontend(&xencons_driver);
557 static void __exit xen_hvc_fini(void)
559 struct xencons_info *entry, *next;
561 if (list_empty(&xenconsoles))
564 list_for_each_entry_safe(entry, next, &xenconsoles, list) {
565 xen_console_remove(entry);
569 static int xen_cons_init(void)
571 const struct hv_ops *ops;
576 if (xen_initial_domain())
582 if (xen_hvm_domain())
583 r = xen_hvm_console_init();
585 r = xen_pv_console_init();
590 hvc_instantiate(HVC_COOKIE, 0, ops);
595 module_init(xen_hvc_init);
596 module_exit(xen_hvc_fini);
597 console_initcall(xen_cons_init);
599 #ifdef CONFIG_EARLY_PRINTK
600 static void xenboot_write_console(struct console *console, const char *string,
603 unsigned int linelen, off = 0;
606 if (!xen_pv_domain())
609 dom0_write_console(0, string, len);
611 if (xen_initial_domain())
614 domU_write_console(0, "(early) ", 8);
615 while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
616 linelen = pos-string+off;
617 if (off + linelen > len)
619 domU_write_console(0, string+off, linelen);
620 domU_write_console(0, "\r\n", 2);
624 domU_write_console(0, string+off, len-off);
627 struct console xenboot_console = {
629 .write = xenboot_write_console,
630 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
632 #endif /* CONFIG_EARLY_PRINTK */
634 void xen_raw_console_write(const char *str)
636 dom0_write_console(0, str, strlen(str));
639 void xen_raw_printk(const char *fmt, ...)
641 static char buf[512];
645 vsnprintf(buf, sizeof(buf), fmt, ap);
648 xen_raw_console_write(buf);