| /* |
| * xen console driver interface to hvc_console.c |
| * |
| * (c) 2007 Gerd Hoffmann <kraxel@suse.de> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include <linux/console.h> |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/irq.h> |
| #include <linux/init.h> |
| #include <linux/types.h> |
| #include <linux/list.h> |
| |
| #include <asm/io.h> |
| #include <asm/xen/hypervisor.h> |
| |
| #include <xen/xen.h> |
| #include <xen/interface/xen.h> |
| #include <xen/hvm.h> |
| #include <xen/grant_table.h> |
| #include <xen/page.h> |
| #include <xen/events.h> |
| #include <xen/interface/io/console.h> |
| #include <xen/interface/sched.h> |
| #include <xen/hvc-console.h> |
| #include <xen/xenbus.h> |
| |
| #include "hvc_console.h" |
| |
| #define HVC_COOKIE 0x58656e /* "Xen" in hex */ |
| |
| struct xencons_info { |
| struct list_head list; |
| struct xenbus_device *xbdev; |
| struct xencons_interface *intf; |
| unsigned int evtchn; |
| struct hvc_struct *hvc; |
| int irq; |
| int vtermno; |
| grant_ref_t gntref; |
| }; |
| |
| static LIST_HEAD(xenconsoles); |
| static DEFINE_SPINLOCK(xencons_lock); |
| |
| /* ------------------------------------------------------------------ */ |
| |
| static struct xencons_info *vtermno_to_xencons(int vtermno) |
| { |
| struct xencons_info *entry, *n, *ret = NULL; |
| |
| if (list_empty(&xenconsoles)) |
| return NULL; |
| |
| list_for_each_entry_safe(entry, n, &xenconsoles, list) { |
| if (entry->vtermno == vtermno) { |
| ret = entry; |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static inline int xenbus_devid_to_vtermno(int devid) |
| { |
| return devid + HVC_COOKIE; |
| } |
| |
| static inline void notify_daemon(struct xencons_info *cons) |
| { |
| /* Use evtchn: this is called early, before irq is set up. */ |
| notify_remote_via_evtchn(cons->evtchn); |
| } |
| |
| static int __write_console(struct xencons_info *xencons, |
| const char *data, int len) |
| { |
| XENCONS_RING_IDX cons, prod; |
| struct xencons_interface *intf = xencons->intf; |
| int sent = 0; |
| |
| cons = intf->out_cons; |
| prod = intf->out_prod; |
| mb(); /* update queue values before going on */ |
| BUG_ON((prod - cons) > sizeof(intf->out)); |
| |
| while ((sent < len) && ((prod - cons) < sizeof(intf->out))) |
| intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++]; |
| |
| wmb(); /* write ring before updating pointer */ |
| intf->out_prod = prod; |
| |
| if (sent) |
| notify_daemon(xencons); |
| return sent; |
| } |
| |
| static int domU_write_console(uint32_t vtermno, const char *data, int len) |
| { |
| int ret = len; |
| struct xencons_info *cons = vtermno_to_xencons(vtermno); |
| if (cons == NULL) |
| return -EINVAL; |
| |
| /* |
| * Make sure the whole buffer is emitted, polling if |
| * necessary. We don't ever want to rely on the hvc daemon |
| * because the most interesting console output is when the |
| * kernel is crippled. |
| */ |
| while (len) { |
| int sent = __write_console(cons, data, len); |
| |
| data += sent; |
| len -= sent; |
| |
| if (unlikely(len)) |
| HYPERVISOR_sched_op(SCHEDOP_yield, NULL); |
| } |
| |
| return ret; |
| } |
| |
| static int domU_read_console(uint32_t vtermno, char *buf, int len) |
| { |
| struct xencons_interface *intf; |
| XENCONS_RING_IDX cons, prod; |
| int recv = 0; |
| struct xencons_info *xencons = vtermno_to_xencons(vtermno); |
| if (xencons == NULL) |
| return -EINVAL; |
| intf = xencons->intf; |
| |
| cons = intf->in_cons; |
| prod = intf->in_prod; |
| mb(); /* get pointers before reading ring */ |
| BUG_ON((prod - cons) > sizeof(intf->in)); |
| |
| while (cons != prod && recv < len) |
| buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)]; |
| |
| mb(); /* read ring before consuming */ |
| intf->in_cons = cons; |
| |
| notify_daemon(xencons); |
| return recv; |
| } |
| |
| static struct hv_ops domU_hvc_ops = { |
| .get_chars = domU_read_console, |
| .put_chars = domU_write_console, |
| .notifier_add = notifier_add_irq, |
| .notifier_del = notifier_del_irq, |
| .notifier_hangup = notifier_hangup_irq, |
| }; |
| |
| static int dom0_read_console(uint32_t vtermno, char *buf, int len) |
| { |
| return HYPERVISOR_console_io(CONSOLEIO_read, len, buf); |
| } |
| |
| /* |
| * Either for a dom0 to write to the system console, or a domU with a |
| * debug version of Xen |
| */ |
| static int dom0_write_console(uint32_t vtermno, const char *str, int len) |
| { |
| int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); |
| if (rc < 0) |
| return 0; |
| |
| return len; |
| } |
| |
| static struct hv_ops dom0_hvc_ops = { |
| .get_chars = dom0_read_console, |
| .put_chars = dom0_write_console, |
| .notifier_add = notifier_add_irq, |
| .notifier_del = notifier_del_irq, |
| .notifier_hangup = notifier_hangup_irq, |
| }; |
| |
| static int xen_hvm_console_init(void) |
| { |
| int r; |
| uint64_t v = 0; |
| unsigned long mfn; |
| struct xencons_info *info; |
| |
| if (!xen_hvm_domain()) |
| return -ENODEV; |
| |
| info = vtermno_to_xencons(HVC_COOKIE); |
| if (!info) { |
| info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO); |
| if (!info) |
| return -ENOMEM; |
| } else if (info->intf != NULL) { |
| /* already configured */ |
| return 0; |
| } |
| /* |
| * If the toolstack (or the hypervisor) hasn't set these values, the |
| * default value is 0. Even though mfn = 0 and evtchn = 0 are |
| * theoretically correct values, in practice they never are and they |
| * mean that a legacy toolstack hasn't initialized the pv console correctly. |
| */ |
| r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v); |
| if (r < 0 || v == 0) |
| goto err; |
| info->evtchn = v; |
| v = 0; |
| r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v); |
| if (r < 0 || v == 0) |
| goto err; |
| mfn = v; |
| info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE); |
| if (info->intf == NULL) |
| goto err; |
| info->vtermno = HVC_COOKIE; |
| |
| spin_lock(&xencons_lock); |
| list_add_tail(&info->list, &xenconsoles); |
| spin_unlock(&xencons_lock); |
| |
| return 0; |
| err: |
| kfree(info); |
| return -ENODEV; |
| } |
| |
| static int xen_pv_console_init(void) |
| { |
| struct xencons_info *info; |
| |
| if (!xen_pv_domain()) |
| return -ENODEV; |
| |
| if (!xen_start_info->console.domU.evtchn) |
| return -ENODEV; |
| |
| info = vtermno_to_xencons(HVC_COOKIE); |
| if (!info) { |
| info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO); |
| if (!info) |
| return -ENOMEM; |
| } else if (info->intf != NULL) { |
| /* already configured */ |
| return 0; |
| } |
| info->evtchn = xen_start_info->console.domU.evtchn; |
| info->intf = mfn_to_virt(xen_start_info->console.domU.mfn); |
| info->vtermno = HVC_COOKIE; |
| |
| spin_lock(&xencons_lock); |
| list_add_tail(&info->list, &xenconsoles); |
| spin_unlock(&xencons_lock); |
| |
| return 0; |
| } |
| |
| static int xen_initial_domain_console_init(void) |
| { |
| struct xencons_info *info; |
| |
| if (!xen_initial_domain()) |
| return -ENODEV; |
| |
| info = vtermno_to_xencons(HVC_COOKIE); |
| if (!info) { |
| info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO); |
| if (!info) |
| return -ENOMEM; |
| } |
| |
| info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0); |
| info->vtermno = HVC_COOKIE; |
| |
| spin_lock(&xencons_lock); |
| list_add_tail(&info->list, &xenconsoles); |
| spin_unlock(&xencons_lock); |
| |
| return 0; |
| } |
| |
| void xen_console_resume(void) |
| { |
| struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE); |
| if (info != NULL && info->irq) |
| rebind_evtchn_irq(info->evtchn, info->irq); |
| } |
| |
| static void xencons_disconnect_backend(struct xencons_info *info) |
| { |
| if (info->irq > 0) |
| unbind_from_irqhandler(info->irq, NULL); |
| info->irq = 0; |
| if (info->evtchn > 0) |
| xenbus_free_evtchn(info->xbdev, info->evtchn); |
| info->evtchn = 0; |
| if (info->gntref > 0) |
| gnttab_free_grant_references(info->gntref); |
| info->gntref = 0; |
| if (info->hvc != NULL) |
| hvc_remove(info->hvc); |
| info->hvc = NULL; |
| } |
| |
| static void xencons_free(struct xencons_info *info) |
| { |
| free_page((unsigned long)info->intf); |
| info->intf = NULL; |
| info->vtermno = 0; |
| kfree(info); |
| } |
| |
| static int xen_console_remove(struct xencons_info *info) |
| { |
| xencons_disconnect_backend(info); |
| spin_lock(&xencons_lock); |
| list_del(&info->list); |
| spin_unlock(&xencons_lock); |
| if (info->xbdev != NULL) |
| xencons_free(info); |
| else { |
| if (xen_hvm_domain()) |
| iounmap(info->intf); |
| kfree(info); |
| } |
| return 0; |
| } |
| |
| #ifdef CONFIG_HVC_XEN_FRONTEND |
| static struct xenbus_driver xencons_driver; |
| |
| static int xencons_remove(struct xenbus_device *dev) |
| { |
| return xen_console_remove(dev_get_drvdata(&dev->dev)); |
| } |
| |
| static int xencons_connect_backend(struct xenbus_device *dev, |
| struct xencons_info *info) |
| { |
| int ret, evtchn, devid, ref, irq; |
| struct xenbus_transaction xbt; |
| grant_ref_t gref_head; |
| unsigned long mfn; |
| |
| ret = xenbus_alloc_evtchn(dev, &evtchn); |
| if (ret) |
| return ret; |
| info->evtchn = evtchn; |
| irq = bind_evtchn_to_irq(evtchn); |
| if (irq < 0) |
| return irq; |
| info->irq = irq; |
| devid = dev->nodename[strlen(dev->nodename) - 1] - '0'; |
| info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid), |
| irq, &domU_hvc_ops, 256); |
| if (IS_ERR(info->hvc)) |
| return PTR_ERR(info->hvc); |
| if (xen_pv_domain()) |
| mfn = virt_to_mfn(info->intf); |
| else |
| mfn = __pa(info->intf) >> PAGE_SHIFT; |
| ret = gnttab_alloc_grant_references(1, &gref_head); |
| if (ret < 0) |
| return ret; |
| info->gntref = gref_head; |
| ref = gnttab_claim_grant_reference(&gref_head); |
| if (ref < 0) |
| return ref; |
| gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id, |
| mfn, 0); |
| |
| again: |
| ret = xenbus_transaction_start(&xbt); |
| if (ret) { |
| xenbus_dev_fatal(dev, ret, "starting transaction"); |
| return ret; |
| } |
| ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref); |
| if (ret) |
| goto error_xenbus; |
| ret = xenbus_printf(xbt, dev->nodename, "port", "%u", |
| evtchn); |
| if (ret) |
| goto error_xenbus; |
| ret = xenbus_printf(xbt, dev->nodename, "type", "ioemu"); |
| if (ret) |
| goto error_xenbus; |
| ret = xenbus_transaction_end(xbt, 0); |
| if (ret) { |
| if (ret == -EAGAIN) |
| goto again; |
| xenbus_dev_fatal(dev, ret, "completing transaction"); |
| return ret; |
| } |
| |
| xenbus_switch_state(dev, XenbusStateInitialised); |
| return 0; |
| |
| error_xenbus: |
| xenbus_transaction_end(xbt, 1); |
| xenbus_dev_fatal(dev, ret, "writing xenstore"); |
| return ret; |
| } |
| |
| static int __devinit xencons_probe(struct xenbus_device *dev, |
| const struct xenbus_device_id *id) |
| { |
| int ret, devid; |
| struct xencons_info *info; |
| |
| devid = dev->nodename[strlen(dev->nodename) - 1] - '0'; |
| if (devid == 0) |
| return -ENODEV; |
| |
| info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL); |
| if (!info) |
| return -ENOMEM; |
| dev_set_drvdata(&dev->dev, info); |
| info->xbdev = dev; |
| info->vtermno = xenbus_devid_to_vtermno(devid); |
| info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
| if (!info->intf) |
| goto error_nomem; |
| |
| ret = xencons_connect_backend(dev, info); |
| if (ret < 0) |
| goto error; |
| spin_lock(&xencons_lock); |
| list_add_tail(&info->list, &xenconsoles); |
| spin_unlock(&xencons_lock); |
| |
| return 0; |
| |
| error_nomem: |
| ret = -ENOMEM; |
| xenbus_dev_fatal(dev, ret, "allocating device memory"); |
| error: |
| xencons_disconnect_backend(info); |
| xencons_free(info); |
| return ret; |
| } |
| |
| static int xencons_resume(struct xenbus_device *dev) |
| { |
| struct xencons_info *info = dev_get_drvdata(&dev->dev); |
| |
| xencons_disconnect_backend(info); |
| memset(info->intf, 0, PAGE_SIZE); |
| return xencons_connect_backend(dev, info); |
| } |
| |
| static void xencons_backend_changed(struct xenbus_device *dev, |
| enum xenbus_state backend_state) |
| { |
| switch (backend_state) { |
| case XenbusStateReconfiguring: |
| case XenbusStateReconfigured: |
| case XenbusStateInitialising: |
| case XenbusStateInitialised: |
| case XenbusStateUnknown: |
| case XenbusStateClosed: |
| break; |
| |
| case XenbusStateInitWait: |
| break; |
| |
| case XenbusStateConnected: |
| xenbus_switch_state(dev, XenbusStateConnected); |
| break; |
| |
| case XenbusStateClosing: |
| xenbus_frontend_closed(dev); |
| break; |
| } |
| } |
| |
| static const struct xenbus_device_id xencons_ids[] = { |
| { "console" }, |
| { "" } |
| }; |
| |
| |
| static DEFINE_XENBUS_DRIVER(xencons, "xenconsole", |
| .probe = xencons_probe, |
| .remove = xencons_remove, |
| .resume = xencons_resume, |
| .otherend_changed = xencons_backend_changed, |
| ); |
| #endif /* CONFIG_HVC_XEN_FRONTEND */ |
| |
| static int __init xen_hvc_init(void) |
| { |
| int r; |
| struct xencons_info *info; |
| const struct hv_ops *ops; |
| |
| if (!xen_domain()) |
| return -ENODEV; |
| |
| if (xen_initial_domain()) { |
| ops = &dom0_hvc_ops; |
| r = xen_initial_domain_console_init(); |
| if (r < 0) |
| return r; |
| info = vtermno_to_xencons(HVC_COOKIE); |
| } else { |
| ops = &domU_hvc_ops; |
| if (xen_hvm_domain()) |
| r = xen_hvm_console_init(); |
| else |
| r = xen_pv_console_init(); |
| if (r < 0) |
| return r; |
| |
| info = vtermno_to_xencons(HVC_COOKIE); |
| info->irq = bind_evtchn_to_irq(info->evtchn); |
| } |
| if (info->irq < 0) |
| info->irq = 0; /* NO_IRQ */ |
| else |
| irq_set_noprobe(info->irq); |
| |
| info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256); |
| if (IS_ERR(info->hvc)) { |
| r = PTR_ERR(info->hvc); |
| spin_lock(&xencons_lock); |
| list_del(&info->list); |
| spin_unlock(&xencons_lock); |
| if (info->irq) |
| unbind_from_irqhandler(info->irq, NULL); |
| kfree(info); |
| return r; |
| } |
| |
| r = 0; |
| #ifdef CONFIG_HVC_XEN_FRONTEND |
| r = xenbus_register_frontend(&xencons_driver); |
| #endif |
| return r; |
| } |
| |
| static void __exit xen_hvc_fini(void) |
| { |
| struct xencons_info *entry, *next; |
| |
| if (list_empty(&xenconsoles)) |
| return; |
| |
| list_for_each_entry_safe(entry, next, &xenconsoles, list) { |
| xen_console_remove(entry); |
| } |
| } |
| |
| static int xen_cons_init(void) |
| { |
| const struct hv_ops *ops; |
| |
| if (!xen_domain()) |
| return 0; |
| |
| if (xen_initial_domain()) |
| ops = &dom0_hvc_ops; |
| else { |
| int r; |
| ops = &domU_hvc_ops; |
| |
| if (xen_hvm_domain()) |
| r = xen_hvm_console_init(); |
| else |
| r = xen_pv_console_init(); |
| if (r < 0) |
| return r; |
| } |
| |
| hvc_instantiate(HVC_COOKIE, 0, ops); |
| return 0; |
| } |
| |
| |
| module_init(xen_hvc_init); |
| module_exit(xen_hvc_fini); |
| console_initcall(xen_cons_init); |
| |
| #ifdef CONFIG_EARLY_PRINTK |
| static void xenboot_write_console(struct console *console, const char *string, |
| unsigned len) |
| { |
| unsigned int linelen, off = 0; |
| const char *pos; |
| |
| if (!xen_pv_domain()) |
| return; |
| |
| dom0_write_console(0, string, len); |
| |
| if (xen_initial_domain()) |
| return; |
| |
| domU_write_console(0, "(early) ", 8); |
| while (off < len && NULL != (pos = strchr(string+off, '\n'))) { |
| linelen = pos-string+off; |
| if (off + linelen > len) |
| break; |
| domU_write_console(0, string+off, linelen); |
| domU_write_console(0, "\r\n", 2); |
| off += linelen + 1; |
| } |
| if (off < len) |
| domU_write_console(0, string+off, len-off); |
| } |
| |
| struct console xenboot_console = { |
| .name = "xenboot", |
| .write = xenboot_write_console, |
| .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME, |
| }; |
| #endif /* CONFIG_EARLY_PRINTK */ |
| |
| void xen_raw_console_write(const char *str) |
| { |
| dom0_write_console(0, str, strlen(str)); |
| } |
| |
| void xen_raw_printk(const char *fmt, ...) |
| { |
| static char buf[512]; |
| va_list ap; |
| |
| va_start(ap, fmt); |
| vsnprintf(buf, sizeof(buf), fmt, ap); |
| va_end(ap); |
| |
| xen_raw_console_write(buf); |
| } |