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>
27 #include <asm/xen/hypervisor.h>
29 #include <xen/events.h>
30 #include <xen/interface/io/console.h>
31 #include <xen/hvc-console.h>
33 #include "hvc_console.h"
35 #define HVC_COOKIE 0x58656e /* "Xen" in hex */
37 static struct hvc_struct *hvc;
38 static int xencons_irq;
40 /* ------------------------------------------------------------------ */
42 static inline struct xencons_interface *xencons_interface(void)
44 return mfn_to_virt(xen_start_info->console.domU.mfn);
47 static inline void notify_daemon(void)
49 /* Use evtchn: this is called early, before irq is set up. */
50 notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
53 static int write_console(uint32_t vtermno, const char *data, int len)
55 struct xencons_interface *intf = xencons_interface();
56 XENCONS_RING_IDX cons, prod;
59 cons = intf->out_cons;
60 prod = intf->out_prod;
61 mb(); /* update queue values before going on */
62 BUG_ON((prod - cons) > sizeof(intf->out));
64 while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
65 intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
67 wmb(); /* write ring before updating pointer */
68 intf->out_prod = prod;
74 static int read_console(uint32_t vtermno, char *buf, int len)
76 struct xencons_interface *intf = xencons_interface();
77 XENCONS_RING_IDX cons, prod;
82 mb(); /* get pointers before reading ring */
83 BUG_ON((prod - cons) > sizeof(intf->in));
85 while (cons != prod && recv < len)
86 buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
88 mb(); /* read ring before consuming */
95 static struct hv_ops hvc_ops = {
96 .get_chars = read_console,
97 .put_chars = write_console,
100 static int __init xen_init(void)
102 struct hvc_struct *hp;
104 if (!is_running_on_xen())
107 xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
109 xencons_irq = 0 /* NO_IRQ */;
110 hp = hvc_alloc(HVC_COOKIE, xencons_irq, &hvc_ops, 256);
118 static void __exit xen_fini(void)
124 static int xen_cons_init(void)
126 if (!is_running_on_xen())
129 hvc_instantiate(HVC_COOKIE, 0, &hvc_ops);
133 module_init(xen_init);
134 module_exit(xen_fini);
135 console_initcall(xen_cons_init);
137 static void raw_console_write(const char *str, int len)
140 int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
149 #ifdef CONFIG_EARLY_PRINTK
150 static void xenboot_write_console(struct console *console, const char *string,
153 unsigned int linelen, off = 0;
156 raw_console_write(string, len);
158 write_console(0, "(early) ", 8);
159 while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
160 linelen = pos-string+off;
161 if (off + linelen > len)
163 write_console(0, string+off, linelen);
164 write_console(0, "\r\n", 2);
168 write_console(0, string+off, len-off);
171 struct console xenboot_console = {
173 .write = xenboot_write_console,
174 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
176 #endif /* CONFIG_EARLY_PRINTK */
178 void xen_raw_console_write(const char *str)
180 raw_console_write(str, strlen(str));
183 void xen_raw_printk(const char *fmt, ...)
185 static char buf[512];
189 vsnprintf(buf, sizeof(buf), fmt, ap);
192 xen_raw_console_write(buf);