/* * 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/init.h> #include <linux/types.h> #include <asm/xen/hypervisor.h> #include <xen/xen.h> #include <xen/page.h> #include <xen/events.h> #include <xen/interface/io/console.h> #include <xen/hvc-console.h> #include "hvc_console.h" #define HVC_COOKIE 0x58656e /* "Xen" in hex */ static struct hvc_struct *hvc; static int xencons_irq; /* ------------------------------------------------------------------ */ static unsigned long console_pfn = ~0ul; static inline struct xencons_interface *xencons_interface(void) { if (console_pfn == ~0ul) return mfn_to_virt(xen_start_info->console.domU.mfn); else return __va(console_pfn << PAGE_SHIFT); } static inline void notify_daemon(void) { /* Use evtchn: this is called early, before irq is set up. */ notify_remote_via_evtchn(xen_start_info->console.domU.evtchn); } static int __write_console(const char *data, int len) { struct xencons_interface *intf = xencons_interface(); XENCONS_RING_IDX cons, prod; 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(); return sent; } static int domU_write_console(uint32_t vtermno, const char *data, int len) { int ret = len; /* * 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(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_interface(); XENCONS_RING_IDX cons, prod; int recv = 0; 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(); 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 __init xen_hvc_init(void) { struct hvc_struct *hp; struct hv_ops *ops; if (!xen_pv_domain()) return -ENODEV; if (xen_initial_domain()) { ops = &dom0_hvc_ops; xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0); } else { if (!xen_start_info->console.domU.evtchn) return -ENODEV; ops = &domU_hvc_ops; xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn); } if (xencons_irq < 0) xencons_irq = 0; /* NO_IRQ */ hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256); if (IS_ERR(hp)) return PTR_ERR(hp); hvc = hp; console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn); return 0; } void xen_console_resume(void) { if (xencons_irq) rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq); } static void __exit xen_hvc_fini(void) { if (hvc) hvc_remove(hvc); } static int xen_cons_init(void) { struct hv_ops *ops; if (!xen_pv_domain()) return 0; if (xen_initial_domain()) ops = &dom0_hvc_ops; else ops = &domU_hvc_ops; 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; 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); }