Commit | Line | Data |
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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> | |
ada64e4c | 17 | #include <linux/kdb.h> |
f2d937f3 | 18 | #include <linux/tty.h> |
efe2f29e | 19 | #include <linux/console.h> |
408a4be1 | 20 | #include <linux/vt_kern.h> |
f2d937f3 JW |
21 | |
22 | #define MAX_CONFIG_LEN 40 | |
23 | ||
24 | static struct kgdb_io kgdboc_io_ops; | |
25 | ||
26 | /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */ | |
27 | static int configured = -1; | |
28 | ||
29 | static char config[MAX_CONFIG_LEN]; | |
30 | static struct kparam_string kps = { | |
31 | .string = config, | |
32 | .maxlen = MAX_CONFIG_LEN, | |
33 | }; | |
34 | ||
408a4be1 | 35 | static int kgdboc_use_kms; /* 1 if we use kernel mode switching */ |
f2d937f3 JW |
36 | static struct tty_driver *kgdb_tty_driver; |
37 | static int kgdb_tty_line; | |
38 | ||
ada64e4c JW |
39 | #ifdef CONFIG_KDB_KEYBOARD |
40 | static int kgdboc_register_kbd(char **cptr) | |
41 | { | |
42 | if (strncmp(*cptr, "kbd", 3) == 0) { | |
43 | if (kdb_poll_idx < KDB_POLL_FUNC_MAX) { | |
44 | kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char; | |
45 | kdb_poll_idx++; | |
46 | if (cptr[0][3] == ',') | |
47 | *cptr += 4; | |
48 | else | |
49 | return 1; | |
50 | } | |
51 | } | |
52 | return 0; | |
53 | } | |
54 | ||
55 | static void kgdboc_unregister_kbd(void) | |
56 | { | |
57 | int i; | |
58 | ||
59 | for (i = 0; i < kdb_poll_idx; i++) { | |
60 | if (kdb_poll_funcs[i] == kdb_get_kbd_char) { | |
61 | kdb_poll_idx--; | |
62 | kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx]; | |
63 | kdb_poll_funcs[kdb_poll_idx] = NULL; | |
64 | i--; | |
65 | } | |
66 | } | |
67 | } | |
68 | #else /* ! CONFIG_KDB_KEYBOARD */ | |
69 | #define kgdboc_register_kbd(x) 0 | |
70 | #define kgdboc_unregister_kbd() | |
71 | #endif /* ! CONFIG_KDB_KEYBOARD */ | |
72 | ||
f2d937f3 JW |
73 | static int kgdboc_option_setup(char *opt) |
74 | { | |
75 | if (strlen(opt) > MAX_CONFIG_LEN) { | |
76 | printk(KERN_ERR "kgdboc: config string too long\n"); | |
77 | return -ENOSPC; | |
78 | } | |
79 | strcpy(config, opt); | |
80 | ||
81 | return 0; | |
82 | } | |
83 | ||
84 | __setup("kgdboc=", kgdboc_option_setup); | |
85 | ||
ada64e4c JW |
86 | static void cleanup_kgdboc(void) |
87 | { | |
88 | kgdboc_unregister_kbd(); | |
89 | if (configured == 1) | |
90 | kgdb_unregister_io_module(&kgdboc_io_ops); | |
91 | } | |
92 | ||
f2d937f3 JW |
93 | static int configure_kgdboc(void) |
94 | { | |
95 | struct tty_driver *p; | |
96 | int tty_line = 0; | |
97 | int err; | |
ada64e4c | 98 | char *cptr = config; |
efe2f29e | 99 | struct console *cons; |
f2d937f3 JW |
100 | |
101 | err = kgdboc_option_setup(config); | |
102 | if (err || !strlen(config) || isspace(config[0])) | |
103 | goto noconfig; | |
104 | ||
105 | err = -ENODEV; | |
efe2f29e | 106 | kgdboc_io_ops.is_console = 0; |
ada64e4c JW |
107 | kgdb_tty_driver = NULL; |
108 | ||
408a4be1 JW |
109 | kgdboc_use_kms = 0; |
110 | if (strncmp(cptr, "kms,", 4) == 0) { | |
111 | cptr += 4; | |
112 | kgdboc_use_kms = 1; | |
113 | } | |
114 | ||
ada64e4c JW |
115 | if (kgdboc_register_kbd(&cptr)) |
116 | goto do_register; | |
f2d937f3 | 117 | |
ada64e4c | 118 | p = tty_find_polling_driver(cptr, &tty_line); |
f2d937f3 JW |
119 | if (!p) |
120 | goto noconfig; | |
121 | ||
efe2f29e JW |
122 | cons = console_drivers; |
123 | while (cons) { | |
124 | int idx; | |
125 | if (cons->device && cons->device(cons, &idx) == p && | |
126 | idx == tty_line) { | |
127 | kgdboc_io_ops.is_console = 1; | |
128 | break; | |
129 | } | |
130 | cons = cons->next; | |
131 | } | |
132 | ||
f2d937f3 JW |
133 | kgdb_tty_driver = p; |
134 | kgdb_tty_line = tty_line; | |
135 | ||
ada64e4c | 136 | do_register: |
f2d937f3 JW |
137 | err = kgdb_register_io_module(&kgdboc_io_ops); |
138 | if (err) | |
139 | goto noconfig; | |
140 | ||
141 | configured = 1; | |
142 | ||
143 | return 0; | |
144 | ||
145 | noconfig: | |
146 | config[0] = 0; | |
147 | configured = 0; | |
ada64e4c | 148 | cleanup_kgdboc(); |
f2d937f3 JW |
149 | |
150 | return err; | |
151 | } | |
152 | ||
153 | static int __init init_kgdboc(void) | |
154 | { | |
155 | /* Already configured? */ | |
156 | if (configured == 1) | |
157 | return 0; | |
158 | ||
159 | return configure_kgdboc(); | |
160 | } | |
161 | ||
f2d937f3 JW |
162 | static int kgdboc_get_char(void) |
163 | { | |
ada64e4c JW |
164 | if (!kgdb_tty_driver) |
165 | return -1; | |
f34d7a5b AC |
166 | return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver, |
167 | kgdb_tty_line); | |
f2d937f3 JW |
168 | } |
169 | ||
170 | static void kgdboc_put_char(u8 chr) | |
171 | { | |
ada64e4c JW |
172 | if (!kgdb_tty_driver) |
173 | return; | |
f34d7a5b AC |
174 | kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver, |
175 | kgdb_tty_line, chr); | |
f2d937f3 JW |
176 | } |
177 | ||
178 | static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp) | |
179 | { | |
c191e5ad JW |
180 | int len = strlen(kmessage); |
181 | ||
182 | if (len >= MAX_CONFIG_LEN) { | |
f2d937f3 JW |
183 | printk(KERN_ERR "kgdboc: config string too long\n"); |
184 | return -ENOSPC; | |
185 | } | |
186 | ||
187 | /* Only copy in the string if the init function has not run yet */ | |
188 | if (configured < 0) { | |
189 | strcpy(config, kmessage); | |
190 | return 0; | |
191 | } | |
192 | ||
193 | if (kgdb_connected) { | |
194 | printk(KERN_ERR | |
195 | "kgdboc: Cannot reconfigure while KGDB is connected.\n"); | |
196 | ||
197 | return -EBUSY; | |
198 | } | |
199 | ||
200 | strcpy(config, kmessage); | |
c191e5ad JW |
201 | /* Chop out \n char as a result of echo */ |
202 | if (config[len - 1] == '\n') | |
203 | config[len - 1] = '\0'; | |
f2d937f3 JW |
204 | |
205 | if (configured == 1) | |
206 | cleanup_kgdboc(); | |
207 | ||
208 | /* Go and configure with the new params. */ | |
209 | return configure_kgdboc(); | |
210 | } | |
211 | ||
408a4be1 JW |
212 | static int dbg_restore_graphics; |
213 | ||
f2d937f3 JW |
214 | static void kgdboc_pre_exp_handler(void) |
215 | { | |
408a4be1 JW |
216 | if (!dbg_restore_graphics && kgdboc_use_kms) { |
217 | dbg_restore_graphics = 1; | |
218 | con_debug_enter(vc_cons[fg_console].d); | |
219 | } | |
f2d937f3 JW |
220 | /* Increment the module count when the debugger is active */ |
221 | if (!kgdb_connected) | |
222 | try_module_get(THIS_MODULE); | |
223 | } | |
224 | ||
225 | static void kgdboc_post_exp_handler(void) | |
226 | { | |
227 | /* decrement the module count when the debugger detaches */ | |
228 | if (!kgdb_connected) | |
229 | module_put(THIS_MODULE); | |
408a4be1 JW |
230 | if (kgdboc_use_kms && dbg_restore_graphics) { |
231 | dbg_restore_graphics = 0; | |
232 | con_debug_leave(); | |
233 | } | |
f2d937f3 JW |
234 | } |
235 | ||
236 | static struct kgdb_io kgdboc_io_ops = { | |
237 | .name = "kgdboc", | |
238 | .read_char = kgdboc_get_char, | |
239 | .write_char = kgdboc_put_char, | |
240 | .pre_exception = kgdboc_pre_exp_handler, | |
241 | .post_exception = kgdboc_post_exp_handler, | |
242 | }; | |
243 | ||
9731191f JW |
244 | #ifdef CONFIG_KGDB_SERIAL_CONSOLE |
245 | /* This is only available if kgdboc is a built in for early debugging */ | |
246 | int __init kgdboc_early_init(char *opt) | |
247 | { | |
248 | /* save the first character of the config string because the | |
249 | * init routine can destroy it. | |
250 | */ | |
251 | char save_ch; | |
252 | ||
253 | kgdboc_option_setup(opt); | |
254 | save_ch = config[0]; | |
255 | init_kgdboc(); | |
256 | config[0] = save_ch; | |
257 | return 0; | |
258 | } | |
259 | ||
260 | early_param("ekgdboc", kgdboc_early_init); | |
261 | #endif /* CONFIG_KGDB_SERIAL_CONSOLE */ | |
262 | ||
f2d937f3 JW |
263 | module_init(init_kgdboc); |
264 | module_exit(cleanup_kgdboc); | |
265 | module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644); | |
266 | MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]"); | |
267 | MODULE_DESCRIPTION("KGDB Console TTY Driver"); | |
268 | MODULE_LICENSE("GPL"); |