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);
223 r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
227 info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
228 if (info->intf == NULL)
230 info->vtermno = HVC_COOKIE;
232 spin_lock(&xencons_lock);
233 list_add_tail(&info->list, &xenconsoles);
234 spin_unlock(&xencons_lock);
242 static int xen_pv_console_init(void)
244 struct xencons_info *info;
246 if (!xen_pv_domain())
249 if (!xen_start_info->console.domU.evtchn)
252 info = vtermno_to_xencons(HVC_COOKIE);
254 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
259 /* already configured */
260 if (info->intf != NULL)
263 info->evtchn = xen_start_info->console.domU.evtchn;
264 info->intf = mfn_to_virt(xen_start_info->console.domU.mfn);
265 info->vtermno = HVC_COOKIE;
267 spin_lock(&xencons_lock);
268 list_add_tail(&info->list, &xenconsoles);
269 spin_unlock(&xencons_lock);
274 static int xen_initial_domain_console_init(void)
276 struct xencons_info *info;
278 if (!xen_initial_domain())
281 info = vtermno_to_xencons(HVC_COOKIE);
283 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
288 info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
289 info->vtermno = HVC_COOKIE;
291 spin_lock(&xencons_lock);
292 list_add_tail(&info->list, &xenconsoles);
293 spin_unlock(&xencons_lock);
298 void xen_console_resume(void)
300 struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
301 if (info != NULL && info->irq)
302 rebind_evtchn_irq(info->evtchn, info->irq);
305 static void xencons_disconnect_backend(struct xencons_info *info)
308 unbind_from_irqhandler(info->irq, NULL);
310 if (info->evtchn > 0)
311 xenbus_free_evtchn(info->xbdev, info->evtchn);
313 if (info->gntref > 0)
314 gnttab_free_grant_references(info->gntref);
316 if (info->hvc != NULL)
317 hvc_remove(info->hvc);
321 static void xencons_free(struct xencons_info *info)
323 free_page((unsigned long)info->intf);
329 static int xen_console_remove(struct xencons_info *info)
331 xencons_disconnect_backend(info);
332 spin_lock(&xencons_lock);
333 list_del(&info->list);
334 spin_unlock(&xencons_lock);
335 if (info->xbdev != NULL)
338 if (xen_hvm_domain())
345 #ifdef CONFIG_HVC_XEN_FRONTEND
346 static struct xenbus_driver xencons_driver;
348 static int xencons_remove(struct xenbus_device *dev)
350 return xen_console_remove(dev_get_drvdata(&dev->dev));
353 static int xencons_connect_backend(struct xenbus_device *dev,
354 struct xencons_info *info)
356 int ret, evtchn, devid, ref, irq;
357 struct xenbus_transaction xbt;
358 grant_ref_t gref_head;
361 ret = xenbus_alloc_evtchn(dev, &evtchn);
364 info->evtchn = evtchn;
365 irq = bind_evtchn_to_irq(evtchn);
369 devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
370 info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
371 irq, &domU_hvc_ops, 256);
372 if (IS_ERR(info->hvc))
373 return PTR_ERR(info->hvc);
375 mfn = virt_to_mfn(info->intf);
377 mfn = __pa(info->intf) >> PAGE_SHIFT;
378 ret = gnttab_alloc_grant_references(1, &gref_head);
381 info->gntref = gref_head;
382 ref = gnttab_claim_grant_reference(&gref_head);
385 gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
389 ret = xenbus_transaction_start(&xbt);
391 xenbus_dev_fatal(dev, ret, "starting transaction");
394 ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref);
397 ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
401 ret = xenbus_printf(xbt, dev->nodename, "type", "ioemu");
404 ret = xenbus_transaction_end(xbt, 0);
408 xenbus_dev_fatal(dev, ret, "completing transaction");
412 xenbus_switch_state(dev, XenbusStateInitialised);
416 xenbus_transaction_end(xbt, 1);
417 xenbus_dev_fatal(dev, ret, "writing xenstore");
421 static int __devinit xencons_probe(struct xenbus_device *dev,
422 const struct xenbus_device_id *id)
425 struct xencons_info *info;
427 devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
431 info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
434 dev_set_drvdata(&dev->dev, info);
436 info->vtermno = xenbus_devid_to_vtermno(devid);
437 info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
441 ret = xencons_connect_backend(dev, info);
444 spin_lock(&xencons_lock);
445 list_add_tail(&info->list, &xenconsoles);
446 spin_unlock(&xencons_lock);
452 xenbus_dev_fatal(dev, ret, "allocating device memory");
454 xencons_disconnect_backend(info);
459 static int xencons_resume(struct xenbus_device *dev)
461 struct xencons_info *info = dev_get_drvdata(&dev->dev);
463 xencons_disconnect_backend(info);
464 memset(info->intf, 0, PAGE_SIZE);
465 return xencons_connect_backend(dev, info);
468 static void xencons_backend_changed(struct xenbus_device *dev,
469 enum xenbus_state backend_state)
471 switch (backend_state) {
472 case XenbusStateReconfiguring:
473 case XenbusStateReconfigured:
474 case XenbusStateInitialising:
475 case XenbusStateInitialised:
476 case XenbusStateUnknown:
477 case XenbusStateClosed:
480 case XenbusStateInitWait:
483 case XenbusStateConnected:
484 xenbus_switch_state(dev, XenbusStateConnected);
487 case XenbusStateClosing:
488 xenbus_frontend_closed(dev);
493 static const struct xenbus_device_id xencons_ids[] = {
499 static DEFINE_XENBUS_DRIVER(xencons, "xenconsole",
500 .probe = xencons_probe,
501 .remove = xencons_remove,
502 .resume = xencons_resume,
503 .otherend_changed = xencons_backend_changed,
505 #endif /* CONFIG_HVC_XEN_FRONTEND */
507 static int __init xen_hvc_init(void)
510 struct xencons_info *info;
511 const struct hv_ops *ops;
516 if (xen_initial_domain()) {
518 r = xen_initial_domain_console_init();
521 info = vtermno_to_xencons(HVC_COOKIE);
524 if (xen_hvm_domain())
525 r = xen_hvm_console_init();
527 r = xen_pv_console_init();
531 info = vtermno_to_xencons(HVC_COOKIE);
532 info->irq = bind_evtchn_to_irq(info->evtchn);
535 info->irq = 0; /* NO_IRQ */
537 irq_set_noprobe(info->irq);
539 info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
540 if (IS_ERR(info->hvc)) {
541 r = PTR_ERR(info->hvc);
542 spin_lock(&xencons_lock);
543 list_del(&info->list);
544 spin_unlock(&xencons_lock);
546 unbind_from_irqhandler(info->irq, NULL);
552 #ifdef CONFIG_HVC_XEN_FRONTEND
553 r = xenbus_register_frontend(&xencons_driver);
558 static void __exit xen_hvc_fini(void)
560 struct xencons_info *entry, *next;
562 if (list_empty(&xenconsoles))
565 list_for_each_entry_safe(entry, next, &xenconsoles, list) {
566 xen_console_remove(entry);
570 static int xen_cons_init(void)
572 const struct hv_ops *ops;
577 if (xen_initial_domain())
583 if (xen_hvm_domain())
584 r = xen_hvm_console_init();
586 r = xen_pv_console_init();
591 hvc_instantiate(HVC_COOKIE, 0, ops);
596 module_init(xen_hvc_init);
597 module_exit(xen_hvc_fini);
598 console_initcall(xen_cons_init);
600 #ifdef CONFIG_EARLY_PRINTK
601 static void xenboot_write_console(struct console *console, const char *string,
604 unsigned int linelen, off = 0;
607 if (!xen_pv_domain())
610 dom0_write_console(0, string, len);
612 if (xen_initial_domain())
615 domU_write_console(0, "(early) ", 8);
616 while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
617 linelen = pos-string+off;
618 if (off + linelen > len)
620 domU_write_console(0, string+off, linelen);
621 domU_write_console(0, "\r\n", 2);
625 domU_write_console(0, string+off, len-off);
628 struct console xenboot_console = {
630 .write = xenboot_write_console,
631 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
633 #endif /* CONFIG_EARLY_PRINTK */
635 void xen_raw_console_write(const char *str)
637 dom0_write_console(0, str, strlen(str));
640 void xen_raw_printk(const char *fmt, ...)
642 static char buf[512];
646 vsnprintf(buf, sizeof(buf), fmt, ap);
649 xen_raw_console_write(buf);