Commit | Line | Data |
---|---|---|
f2d937f3 JW |
1 | /* |
2 | * Based on the same principle as kgdboe using the NETPOLL api, this | |
3 | * driver uses a console polling api to implement a gdb serial inteface | |
4 | * which is multiplexed on a console port. | |
5 | * | |
6 | * Maintainer: Jason Wessel <jason.wessel@windriver.com> | |
7 | * | |
8 | * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc. | |
9 | * | |
10 | * This file is licensed under the terms of the GNU General Public | |
11 | * License version 2. This program is licensed "as is" without any | |
12 | * warranty of any kind, whether express or implied. | |
13 | */ | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/ctype.h> | |
16 | #include <linux/kgdb.h> | |
17 | #include <linux/tty.h> | |
18 | ||
19 | #define MAX_CONFIG_LEN 40 | |
20 | ||
21 | static struct kgdb_io kgdboc_io_ops; | |
22 | ||
23 | /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */ | |
24 | static int configured = -1; | |
25 | ||
26 | static char config[MAX_CONFIG_LEN]; | |
27 | static struct kparam_string kps = { | |
28 | .string = config, | |
29 | .maxlen = MAX_CONFIG_LEN, | |
30 | }; | |
31 | ||
32 | static struct tty_driver *kgdb_tty_driver; | |
33 | static int kgdb_tty_line; | |
34 | ||
35 | static int kgdboc_option_setup(char *opt) | |
36 | { | |
37 | if (strlen(opt) > MAX_CONFIG_LEN) { | |
38 | printk(KERN_ERR "kgdboc: config string too long\n"); | |
39 | return -ENOSPC; | |
40 | } | |
41 | strcpy(config, opt); | |
42 | ||
43 | return 0; | |
44 | } | |
45 | ||
46 | __setup("kgdboc=", kgdboc_option_setup); | |
47 | ||
48 | static int configure_kgdboc(void) | |
49 | { | |
50 | struct tty_driver *p; | |
51 | int tty_line = 0; | |
52 | int err; | |
53 | ||
54 | err = kgdboc_option_setup(config); | |
55 | if (err || !strlen(config) || isspace(config[0])) | |
56 | goto noconfig; | |
57 | ||
58 | err = -ENODEV; | |
59 | ||
60 | p = tty_find_polling_driver(config, &tty_line); | |
61 | if (!p) | |
62 | goto noconfig; | |
63 | ||
64 | kgdb_tty_driver = p; | |
65 | kgdb_tty_line = tty_line; | |
66 | ||
67 | err = kgdb_register_io_module(&kgdboc_io_ops); | |
68 | if (err) | |
69 | goto noconfig; | |
70 | ||
71 | configured = 1; | |
72 | ||
73 | return 0; | |
74 | ||
75 | noconfig: | |
76 | config[0] = 0; | |
77 | configured = 0; | |
78 | ||
79 | return err; | |
80 | } | |
81 | ||
82 | static int __init init_kgdboc(void) | |
83 | { | |
84 | /* Already configured? */ | |
85 | if (configured == 1) | |
86 | return 0; | |
87 | ||
88 | return configure_kgdboc(); | |
89 | } | |
90 | ||
91 | static void cleanup_kgdboc(void) | |
92 | { | |
93 | if (configured == 1) | |
94 | kgdb_unregister_io_module(&kgdboc_io_ops); | |
95 | } | |
96 | ||
97 | static int kgdboc_get_char(void) | |
98 | { | |
f34d7a5b AC |
99 | return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver, |
100 | kgdb_tty_line); | |
f2d937f3 JW |
101 | } |
102 | ||
103 | static void kgdboc_put_char(u8 chr) | |
104 | { | |
f34d7a5b AC |
105 | kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver, |
106 | kgdb_tty_line, chr); | |
f2d937f3 JW |
107 | } |
108 | ||
109 | static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp) | |
110 | { | |
c191e5ad JW |
111 | int len = strlen(kmessage); |
112 | ||
113 | if (len >= MAX_CONFIG_LEN) { | |
f2d937f3 JW |
114 | printk(KERN_ERR "kgdboc: config string too long\n"); |
115 | return -ENOSPC; | |
116 | } | |
117 | ||
118 | /* Only copy in the string if the init function has not run yet */ | |
119 | if (configured < 0) { | |
120 | strcpy(config, kmessage); | |
121 | return 0; | |
122 | } | |
123 | ||
124 | if (kgdb_connected) { | |
125 | printk(KERN_ERR | |
126 | "kgdboc: Cannot reconfigure while KGDB is connected.\n"); | |
127 | ||
128 | return -EBUSY; | |
129 | } | |
130 | ||
131 | strcpy(config, kmessage); | |
c191e5ad JW |
132 | /* Chop out \n char as a result of echo */ |
133 | if (config[len - 1] == '\n') | |
134 | config[len - 1] = '\0'; | |
f2d937f3 JW |
135 | |
136 | if (configured == 1) | |
137 | cleanup_kgdboc(); | |
138 | ||
139 | /* Go and configure with the new params. */ | |
140 | return configure_kgdboc(); | |
141 | } | |
142 | ||
143 | static void kgdboc_pre_exp_handler(void) | |
144 | { | |
145 | /* Increment the module count when the debugger is active */ | |
146 | if (!kgdb_connected) | |
147 | try_module_get(THIS_MODULE); | |
148 | } | |
149 | ||
150 | static void kgdboc_post_exp_handler(void) | |
151 | { | |
152 | /* decrement the module count when the debugger detaches */ | |
153 | if (!kgdb_connected) | |
154 | module_put(THIS_MODULE); | |
155 | } | |
156 | ||
157 | static struct kgdb_io kgdboc_io_ops = { | |
158 | .name = "kgdboc", | |
159 | .read_char = kgdboc_get_char, | |
160 | .write_char = kgdboc_put_char, | |
161 | .pre_exception = kgdboc_pre_exp_handler, | |
162 | .post_exception = kgdboc_post_exp_handler, | |
163 | }; | |
164 | ||
165 | module_init(init_kgdboc); | |
166 | module_exit(cleanup_kgdboc); | |
167 | module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644); | |
168 | MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]"); | |
169 | MODULE_DESCRIPTION("KGDB Console TTY Driver"); | |
170 | MODULE_LICENSE("GPL"); |