/* * 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/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 inline struct xencons_interface *xencons_interface(void) { return mfn_to_virt(xen_start_info->console.domU.mfn); } 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(uint32_t vtermno, 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; notify_daemon(); return sent; } static int 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 hvc_ops = { .get_chars = read_console, .put_chars = write_console, }; static int __init xen_init(void) { struct hvc_struct *hp; if (!is_running_on_xen()) return 0; 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, &hvc_ops, 256); if (IS_ERR(hp)) return PTR_ERR(hp); hvc = hp; return 0; } static void __exit xen_fini(void) { if (hvc) hvc_remove(hvc); } static int xen_cons_init(void) { if (!is_running_on_xen()) return 0; hvc_instantiate(HVC_COOKIE, 0, &hvc_ops); return 0; } module_init(xen_init); module_exit(xen_fini); console_initcall(xen_cons_init); static void xenboot_write_console(struct console *console, const char *string, unsigned len) { unsigned int linelen, off = 0; const char *pos; while (off < len && NULL != (pos = strchr(string+off, '\n'))) { linelen = pos-string+off; if (off + linelen > len) break; write_console(0, string+off, linelen); write_console(0, "\r\n", 2); off += linelen + 1; } if (off < len) write_console(0, string+off, len-off); } struct console xenboot_console = { .name = "xenboot", .write = xenboot_write_console, .flags = CON_PRINTBUFFER | CON_BOOT, };