ia64/linux-2.6.18-xen.hg

view drivers/char/hvc_rtas.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * IBM RTAS driver interface to hvc_console.c
3 *
4 * (C) Copyright IBM Corporation 2001-2005
5 * (C) Copyright Red Hat, Inc. 2005
6 *
7 * Author(s): Maximino Augilar <IBM STI Design Center>
8 * : Ryan S. Arnold <rsa@us.ibm.com>
9 * : Utz Bacher <utz.bacher@de.ibm.com>
10 * : David Woodhouse <dwmw2@infradead.org>
11 *
12 * inspired by drivers/char/hvc_console.c
13 * written by Anton Blanchard and Paul Mackerras
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or
18 * (at your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 */
30 #include <linux/console.h>
31 #include <linux/delay.h>
32 #include <linux/err.h>
33 #include <linux/init.h>
34 #include <linux/moduleparam.h>
35 #include <linux/types.h>
37 #include <asm/irq.h>
38 #include <asm/rtas.h>
39 #include "hvc_console.h"
41 #define hvc_rtas_cookie 0x67781e15
42 struct hvc_struct *hvc_rtas_dev;
44 static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
45 static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
47 static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf,
48 int count)
49 {
50 int i;
52 for (i = 0; i < count; i++) {
53 if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
54 break;
55 }
57 return i;
58 }
60 static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
61 {
62 int i, c;
64 for (i = 0; i < count; i++) {
65 if (rtas_call(rtascons_get_char_token, 0, 2, &c))
66 break;
68 buf[i] = c;
69 }
71 return i;
72 }
74 static struct hv_ops hvc_rtas_get_put_ops = {
75 .get_chars = hvc_rtas_read_console,
76 .put_chars = hvc_rtas_write_console,
77 };
79 static int hvc_rtas_init(void)
80 {
81 struct hvc_struct *hp;
83 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
84 rtascons_put_char_token = rtas_token("put-term-char");
85 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
86 return -EIO;
88 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
89 rtascons_get_char_token = rtas_token("get-term-char");
90 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
91 return -EIO;
93 BUG_ON(hvc_rtas_dev);
95 /* Allocate an hvc_struct for the console device we instantiated
96 * earlier. Save off hp so that we can return it on exit */
97 hp = hvc_alloc(hvc_rtas_cookie, NO_IRQ, &hvc_rtas_get_put_ops);
98 if (IS_ERR(hp))
99 return PTR_ERR(hp);
101 hvc_rtas_dev = hp;
103 return 0;
104 }
105 module_init(hvc_rtas_init);
107 /* This will tear down the tty portion of the driver */
108 static void __exit hvc_rtas_exit(void)
109 {
110 /* Really the fun isn't over until the worker thread breaks down and
111 * the tty cleans up */
112 if (hvc_rtas_dev)
113 hvc_remove(hvc_rtas_dev);
114 }
115 module_exit(hvc_rtas_exit);
117 /* This will happen prior to module init. There is no tty at this time? */
118 static int hvc_rtas_console_init(void)
119 {
120 rtascons_put_char_token = rtas_token("put-term-char");
121 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
122 return -EIO;
124 rtascons_get_char_token = rtas_token("get-term-char");
125 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
126 return -EIO;
128 hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
129 add_preferred_console("hvc", 0, NULL);
131 return 0;
132 }
133 console_initcall(hvc_rtas_console_init);