blob: 3740e327f1802f0e63bd1cdffba4107cbbf55c7e [file] [log] [blame]
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -07001/*
2 * xen console driver interface to hvc_console.c
3 *
4 * (c) 2007 Gerd Hoffmann <kraxel@suse.de>
5 *
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.
10 *
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.
15 *
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
19 */
20
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
27#include <asm/xen/hypervisor.h>
Jeremy Fitzhardinge1ccbf532009-10-06 15:11:14 -070028
29#include <xen/xen.h>
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -070030#include <xen/page.h>
31#include <xen/events.h>
32#include <xen/interface/io/console.h>
33#include <xen/hvc-console.h>
34
35#include "hvc_console.h"
36
37#define HVC_COOKIE 0x58656e /* "Xen" in hex */
38
39static struct hvc_struct *hvc;
40static int xencons_irq;
41
42/* ------------------------------------------------------------------ */
43
Jeremy Fitzhardinge6b9b7322008-05-26 23:31:25 +010044static unsigned long console_pfn = ~0ul;
45
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -070046static inline struct xencons_interface *xencons_interface(void)
47{
Jeremy Fitzhardinge6b9b7322008-05-26 23:31:25 +010048 if (console_pfn == ~0ul)
49 return mfn_to_virt(xen_start_info->console.domU.mfn);
50 else
51 return __va(console_pfn << PAGE_SHIFT);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -070052}
53
54static inline void notify_daemon(void)
55{
56 /* Use evtchn: this is called early, before irq is set up. */
57 notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
58}
59
Jeremy Fitzhardinge7825cf12009-10-20 15:28:21 +090060static int __write_console(const char *data, int len)
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -070061{
62 struct xencons_interface *intf = xencons_interface();
63 XENCONS_RING_IDX cons, prod;
64 int sent = 0;
65
66 cons = intf->out_cons;
67 prod = intf->out_prod;
68 mb(); /* update queue values before going on */
69 BUG_ON((prod - cons) > sizeof(intf->out));
70
71 while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
72 intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
73
74 wmb(); /* write ring before updating pointer */
75 intf->out_prod = prod;
76
Jeremy Fitzhardinge403a85f2010-10-14 11:38:47 -070077 if (sent)
78 notify_daemon();
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -070079 return sent;
80}
81
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +010082static int domU_write_console(uint32_t vtermno, const char *data, int len)
Jeremy Fitzhardinge7825cf12009-10-20 15:28:21 +090083{
84 int ret = len;
85
86 /*
87 * Make sure the whole buffer is emitted, polling if
88 * necessary. We don't ever want to rely on the hvc daemon
89 * because the most interesting console output is when the
90 * kernel is crippled.
91 */
92 while (len) {
93 int sent = __write_console(data, len);
94
95 data += sent;
96 len -= sent;
97
98 if (unlikely(len))
99 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
100 }
101
102 return ret;
103}
104
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100105static int domU_read_console(uint32_t vtermno, char *buf, int len)
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700106{
107 struct xencons_interface *intf = xencons_interface();
108 XENCONS_RING_IDX cons, prod;
109 int recv = 0;
110
111 cons = intf->in_cons;
112 prod = intf->in_prod;
113 mb(); /* get pointers before reading ring */
114 BUG_ON((prod - cons) > sizeof(intf->in));
115
116 while (cons != prod && recv < len)
117 buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
118
119 mb(); /* read ring before consuming */
120 intf->in_cons = cons;
121
122 notify_daemon();
123 return recv;
124}
125
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100126static struct hv_ops domU_hvc_ops = {
127 .get_chars = domU_read_console,
128 .put_chars = domU_write_console,
Christian Borntraeger611e0972008-06-20 15:24:08 +0200129 .notifier_add = notifier_add_irq,
130 .notifier_del = notifier_del_irq,
Hendrik Bruecknerfc362e22008-10-13 23:12:48 +0000131 .notifier_hangup = notifier_hangup_irq,
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700132};
133
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100134static int dom0_read_console(uint32_t vtermno, char *buf, int len)
135{
136 return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
137}
138
139/*
140 * Either for a dom0 to write to the system console, or a domU with a
141 * debug version of Xen
142 */
143static int dom0_write_console(uint32_t vtermno, const char *str, int len)
144{
145 int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
146 if (rc < 0)
147 return 0;
148
149 return len;
150}
151
152static struct hv_ops dom0_hvc_ops = {
153 .get_chars = dom0_read_console,
154 .put_chars = dom0_write_console,
155 .notifier_add = notifier_add_irq,
156 .notifier_del = notifier_del_irq,
157 .notifier_hangup = notifier_hangup_irq,
158};
159
160static int __init xen_hvc_init(void)
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700161{
162 struct hvc_struct *hp;
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100163 struct hv_ops *ops;
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700164
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100165 if (!xen_pv_domain())
Jeremy Fitzhardinge6b9b7322008-05-26 23:31:25 +0100166 return -ENODEV;
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700167
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100168 if (xen_initial_domain()) {
169 ops = &dom0_hvc_ops;
170 xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
171 } else {
172 if (!xen_start_info->console.domU.evtchn)
173 return -ENODEV;
174
175 ops = &domU_hvc_ops;
176 xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
177 }
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700178 if (xencons_irq < 0)
Jeremy Fitzhardinge6b9b7322008-05-26 23:31:25 +0100179 xencons_irq = 0; /* NO_IRQ */
180
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100181 hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700182 if (IS_ERR(hp))
183 return PTR_ERR(hp);
184
185 hvc = hp;
Jeremy Fitzhardinge6b9b7322008-05-26 23:31:25 +0100186
187 console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
188
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700189 return 0;
190}
191
Jeremy Fitzhardinge6b9b7322008-05-26 23:31:25 +0100192void xen_console_resume(void)
193{
194 if (xencons_irq)
195 rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq);
196}
197
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100198static void __exit xen_hvc_fini(void)
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700199{
200 if (hvc)
201 hvc_remove(hvc);
202}
203
204static int xen_cons_init(void)
205{
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100206 struct hv_ops *ops;
207
Jeremy Fitzhardinge6e833582008-08-19 13:16:17 -0700208 if (!xen_pv_domain())
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700209 return 0;
210
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100211 if (xen_initial_domain())
212 ops = &dom0_hvc_ops;
213 else
214 ops = &domU_hvc_ops;
215
216 hvc_instantiate(HVC_COOKIE, 0, ops);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700217 return 0;
218}
219
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100220module_init(xen_hvc_init);
221module_exit(xen_hvc_fini);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700222console_initcall(xen_cons_init);
223
Jeremy Fitzhardinge0922abd2008-05-26 23:31:00 +0100224#ifdef CONFIG_EARLY_PRINTK
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700225static void xenboot_write_console(struct console *console, const char *string,
226 unsigned len)
227{
228 unsigned int linelen, off = 0;
229 const char *pos;
230
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100231 dom0_write_console(0, string, len);
Jeremy Fitzhardinge0922abd2008-05-26 23:31:00 +0100232
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100233 if (xen_initial_domain())
234 return;
235
236 domU_write_console(0, "(early) ", 8);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700237 while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
238 linelen = pos-string+off;
239 if (off + linelen > len)
240 break;
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100241 domU_write_console(0, string+off, linelen);
242 domU_write_console(0, "\r\n", 2);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700243 off += linelen + 1;
244 }
245 if (off < len)
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100246 domU_write_console(0, string+off, len-off);
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700247}
248
249struct console xenboot_console = {
250 .name = "xenboot",
251 .write = xenboot_write_console,
Jeremy Fitzhardinge0922abd2008-05-26 23:31:00 +0100252 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
Jeremy Fitzhardingeb536b4b2007-07-17 18:37:06 -0700253};
Jeremy Fitzhardinge0922abd2008-05-26 23:31:00 +0100254#endif /* CONFIG_EARLY_PRINTK */
Jeremy Fitzhardinge0acf10d2008-05-26 23:30:59 +0100255
256void xen_raw_console_write(const char *str)
257{
Jeremy Fitzhardinge4fe7d5a2010-09-02 16:17:06 +0100258 dom0_write_console(0, str, strlen(str));
Jeremy Fitzhardinge0acf10d2008-05-26 23:30:59 +0100259}
260
261void xen_raw_printk(const char *fmt, ...)
262{
263 static char buf[512];
264 va_list ap;
265
266 va_start(ap, fmt);
267 vsnprintf(buf, sizeof(buf), fmt, ap);
268 va_end(ap);
269
270 xen_raw_console_write(buf);
271}