Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/include/linux/console.h | |
3 | * | |
4 | * Copyright (C) 1993 Hamish Macdonald | |
5 | * | |
6 | * This file is subject to the terms and conditions of the GNU General Public | |
7 | * License. See the file COPYING in the main directory of this archive | |
8 | * for more details. | |
9 | * | |
10 | * Changed: | |
11 | * 10-Mar-94: Arno Griffioen: Conversion for vt100 emulator port from PC LINUX | |
12 | */ | |
13 | ||
14 | #ifndef _LINUX_CONSOLE_H_ | |
15 | #define _LINUX_CONSOLE_H_ 1 | |
16 | ||
56e6c104 | 17 | #include <linux/atomic.h> |
6c4afa79 | 18 | #include <linux/rculist.h> |
1da177e4 | 19 | #include <linux/types.h> |
1da177e4 LT |
20 | |
21 | struct vc_data; | |
22 | struct console_font_op; | |
23 | struct console_font; | |
24 | struct module; | |
1b135431 | 25 | struct tty_struct; |
83d83beb | 26 | struct notifier_block; |
1da177e4 | 27 | |
d705ff38 JS |
28 | enum con_scroll { |
29 | SM_UP, | |
30 | SM_DOWN, | |
31 | }; | |
32 | ||
b84ae3dc JS |
33 | enum vc_intensity; |
34 | ||
97293de9 JS |
35 | /** |
36 | * struct consw - callbacks for consoles | |
37 | * | |
d705ff38 JS |
38 | * @con_scroll: move lines from @top to @bottom in direction @dir by @lines. |
39 | * Return true if no generic handling should be done. | |
40 | * Invoked by csi_M and printing to the console. | |
709280da | 41 | * @con_set_palette: sets the palette of the console to @table (optional) |
97293de9 JS |
42 | * @con_scrolldelta: the contents of the console should be scrolled by @lines. |
43 | * Invoked by user. (optional) | |
44 | */ | |
1da177e4 LT |
45 | struct consw { |
46 | struct module *owner; | |
47 | const char *(*con_startup)(void); | |
209f668c KC |
48 | void (*con_init)(struct vc_data *vc, int init); |
49 | void (*con_deinit)(struct vc_data *vc); | |
50 | void (*con_clear)(struct vc_data *vc, int sy, int sx, int height, | |
51 | int width); | |
52 | void (*con_putc)(struct vc_data *vc, int c, int ypos, int xpos); | |
53 | void (*con_putcs)(struct vc_data *vc, const unsigned short *s, | |
54 | int count, int ypos, int xpos); | |
55 | void (*con_cursor)(struct vc_data *vc, int mode); | |
56 | bool (*con_scroll)(struct vc_data *vc, unsigned int top, | |
d705ff38 JS |
57 | unsigned int bottom, enum con_scroll dir, |
58 | unsigned int lines); | |
209f668c KC |
59 | int (*con_switch)(struct vc_data *vc); |
60 | int (*con_blank)(struct vc_data *vc, int blank, int mode_switch); | |
61 | int (*con_font_set)(struct vc_data *vc, struct console_font *font, | |
62 | unsigned int flags); | |
63 | int (*con_font_get)(struct vc_data *vc, struct console_font *font); | |
64 | int (*con_font_default)(struct vc_data *vc, | |
65 | struct console_font *font, char *name); | |
209f668c KC |
66 | int (*con_resize)(struct vc_data *vc, unsigned int width, |
67 | unsigned int height, unsigned int user); | |
68 | void (*con_set_palette)(struct vc_data *vc, | |
709280da | 69 | const unsigned char *table); |
209f668c KC |
70 | void (*con_scrolldelta)(struct vc_data *vc, int lines); |
71 | int (*con_set_origin)(struct vc_data *vc); | |
72 | void (*con_save_screen)(struct vc_data *vc); | |
b84ae3dc JS |
73 | u8 (*con_build_attr)(struct vc_data *vc, u8 color, |
74 | enum vc_intensity intensity, | |
77bc14f2 | 75 | bool blink, bool underline, bool reverse, bool italic); |
209f668c | 76 | void (*con_invert_region)(struct vc_data *vc, u16 *p, int count); |
d73568c4 | 77 | u16 *(*con_screen_pos)(const struct vc_data *vc, int offset); |
209f668c KC |
78 | unsigned long (*con_getxy)(struct vc_data *vc, unsigned long position, |
79 | int *px, int *py); | |
bcd375f7 MS |
80 | /* |
81 | * Flush the video console driver's scrollback buffer | |
82 | */ | |
209f668c | 83 | void (*con_flush_scrollback)(struct vc_data *vc); |
b45cfba4 JB |
84 | /* |
85 | * Prepare the console for the debugger. This includes, but is not | |
86 | * limited to, unblanking the console, loading an appropriate | |
87 | * palette, and allowing debugger generated output. | |
88 | */ | |
209f668c | 89 | int (*con_debug_enter)(struct vc_data *vc); |
b45cfba4 JB |
90 | /* |
91 | * Restore the console to its pre-debug state as closely as possible. | |
92 | */ | |
209f668c | 93 | int (*con_debug_leave)(struct vc_data *vc); |
1da177e4 LT |
94 | }; |
95 | ||
96 | extern const struct consw *conswitchp; | |
97 | ||
98 | extern const struct consw dummy_con; /* dummy console buffer */ | |
99 | extern const struct consw vga_con; /* VGA text console */ | |
100 | extern const struct consw newport_con; /* SGI Newport console */ | |
1da177e4 | 101 | |
3e795de7 | 102 | int con_is_bound(const struct consw *csw); |
e93a9a86 | 103 | int do_unregister_con_driver(const struct consw *csw); |
50e244cc | 104 | int do_take_over_console(const struct consw *sw, int first, int last, int deflt); |
1da177e4 | 105 | void give_up_console(const struct consw *sw); |
9261ec1a | 106 | #ifdef CONFIG_HW_CONSOLE |
b45cfba4 JB |
107 | int con_debug_enter(struct vc_data *vc); |
108 | int con_debug_leave(void); | |
9261ec1a | 109 | #else |
f2f0945e AB |
110 | static inline int con_debug_enter(struct vc_data *vc) |
111 | { | |
112 | return 0; | |
113 | } | |
114 | static inline int con_debug_leave(void) | |
115 | { | |
116 | return 0; | |
117 | } | |
9261ec1a | 118 | #endif |
b45cfba4 | 119 | |
1da177e4 LT |
120 | /* cursor */ |
121 | #define CM_DRAW (1) | |
122 | #define CM_ERASE (2) | |
123 | #define CM_MOVE (3) | |
124 | ||
125 | /* | |
126 | * The interface for a console, or any other device that wants to capture | |
127 | * console messages (printer driver?) | |
128 | * | |
129 | * If a console driver is marked CON_BOOT then it will be auto-unregistered | |
130 | * when the first real console is registered. This is for early-printk drivers. | |
131 | */ | |
132 | ||
133 | #define CON_PRINTBUFFER (1) | |
33225d7b | 134 | #define CON_CONSDEV (2) /* Preferred console, /dev/console */ |
1da177e4 LT |
135 | #define CON_ENABLED (4) |
136 | #define CON_BOOT (8) | |
76a8ad29 | 137 | #define CON_ANYTIME (16) /* Safe to call when cpu is offline */ |
f7511d5f | 138 | #define CON_BRL (32) /* Used for a braille device */ |
6fe29354 | 139 | #define CON_EXTENDED (64) /* Use the extended output format a la /dev/kmsg */ |
1da177e4 | 140 | |
6ae9200f AM |
141 | struct console { |
142 | char name[16]; | |
1da177e4 LT |
143 | void (*write)(struct console *, const char *, unsigned); |
144 | int (*read)(struct console *, char *, unsigned); | |
145 | struct tty_driver *(*device)(struct console *, int *); | |
146 | void (*unblank)(void); | |
147 | int (*setup)(struct console *, char *); | |
ed31685c | 148 | int (*exit)(struct console *); |
c7cef0a8 | 149 | int (*match)(struct console *, char *name, int idx, char *options); |
1da177e4 LT |
150 | short flags; |
151 | short index; | |
152 | int cflag; | |
027b5717 PR |
153 | uint ispeed; |
154 | uint ospeed; | |
a699449b JO |
155 | u64 seq; |
156 | unsigned long dropped; | |
1da177e4 | 157 | void *data; |
d9a4af56 | 158 | struct hlist_node node; |
1da177e4 LT |
159 | }; |
160 | ||
4dc64682 JO |
161 | #ifdef CONFIG_LOCKDEP |
162 | extern void lockdep_assert_console_list_lock_held(void); | |
163 | #else | |
164 | static inline void lockdep_assert_console_list_lock_held(void) | |
165 | { | |
166 | } | |
167 | #endif | |
168 | ||
6c4afa79 JO |
169 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
170 | extern bool console_srcu_read_lock_is_held(void); | |
171 | #else | |
172 | static inline bool console_srcu_read_lock_is_held(void) | |
173 | { | |
174 | return 1; | |
175 | } | |
176 | #endif | |
177 | ||
178 | extern int console_srcu_read_lock(void); | |
179 | extern void console_srcu_read_unlock(int cookie); | |
180 | ||
4dc64682 JO |
181 | extern void console_list_lock(void) __acquires(console_mutex); |
182 | extern void console_list_unlock(void) __releases(console_mutex); | |
183 | ||
d9a4af56 TG |
184 | extern struct hlist_head console_list; |
185 | ||
100bdef2 JO |
186 | /** |
187 | * console_srcu_read_flags - Locklessly read the console flags | |
188 | * @con: struct console pointer of console to read flags from | |
189 | * | |
190 | * This function provides the necessary READ_ONCE() and data_race() | |
191 | * notation for locklessly reading the console flags. The READ_ONCE() | |
192 | * in this function matches the WRITE_ONCE() when @flags are modified | |
193 | * for registered consoles with console_srcu_write_flags(). | |
194 | * | |
195 | * Only use this function to read console flags when locklessly | |
196 | * iterating the console list via srcu. | |
197 | * | |
198 | * Context: Any context. | |
199 | */ | |
200 | static inline short console_srcu_read_flags(const struct console *con) | |
201 | { | |
202 | WARN_ON_ONCE(!console_srcu_read_lock_is_held()); | |
203 | ||
204 | /* | |
205 | * Locklessly reading console->flags provides a consistent | |
206 | * read value because there is at most one CPU modifying | |
207 | * console->flags and that CPU is using only read-modify-write | |
208 | * operations to do so. | |
209 | */ | |
210 | return data_race(READ_ONCE(con->flags)); | |
211 | } | |
212 | ||
213 | /** | |
214 | * console_srcu_write_flags - Write flags for a registered console | |
215 | * @con: struct console pointer of console to write flags to | |
216 | * @flags: new flags value to write | |
217 | * | |
218 | * Only use this function to write flags for registered consoles. It | |
219 | * requires holding the console_list_lock. | |
220 | * | |
221 | * Context: Any context. | |
222 | */ | |
223 | static inline void console_srcu_write_flags(struct console *con, short flags) | |
224 | { | |
225 | lockdep_assert_console_list_lock_held(); | |
226 | ||
227 | /* This matches the READ_ONCE() in console_srcu_read_flags(). */ | |
228 | WRITE_ONCE(con->flags, flags); | |
229 | } | |
230 | ||
1fd4224a JO |
231 | /* Variant of console_is_registered() when the console_list_lock is held. */ |
232 | static inline bool console_is_registered_locked(const struct console *con) | |
233 | { | |
234 | lockdep_assert_console_list_lock_held(); | |
235 | return !hlist_unhashed(&con->node); | |
236 | } | |
237 | ||
238 | /* | |
239 | * console_is_registered - Check if the console is registered | |
240 | * @con: struct console pointer of console to check | |
241 | * | |
242 | * Context: Process context. May sleep while acquiring console list lock. | |
243 | * Return: true if the console is in the console list, otherwise false. | |
244 | * | |
245 | * If false is returned for a console that was previously registered, it | |
246 | * can be assumed that the console's unregistration is fully completed, | |
247 | * including the exit() callback after console list removal. | |
248 | */ | |
249 | static inline bool console_is_registered(const struct console *con) | |
250 | { | |
251 | bool ret; | |
252 | ||
253 | console_list_lock(); | |
254 | ret = console_is_registered_locked(con); | |
255 | console_list_unlock(); | |
256 | return ret; | |
257 | } | |
258 | ||
6c4afa79 JO |
259 | /** |
260 | * for_each_console_srcu() - Iterator over registered consoles | |
261 | * @con: struct console pointer used as loop cursor | |
262 | * | |
263 | * Although SRCU guarantees the console list will be consistent, the | |
264 | * struct console fields may be updated by other CPUs while iterating. | |
265 | * | |
266 | * Requires console_srcu_read_lock to be held. Can be invoked from | |
267 | * any context. | |
268 | */ | |
269 | #define for_each_console_srcu(con) \ | |
270 | hlist_for_each_entry_srcu(con, &console_list, node, \ | |
271 | console_srcu_read_lock_is_held()) | |
272 | ||
4dc64682 JO |
273 | /** |
274 | * for_each_console() - Iterator over registered consoles | |
275 | * @con: struct console pointer used as loop cursor | |
276 | * | |
277 | * The console list and the console->flags are immutable while iterating. | |
278 | * | |
279 | * Requires console_list_lock to be held. | |
a75d946f | 280 | */ |
4dc64682 JO |
281 | #define for_each_console(con) \ |
282 | lockdep_assert_console_list_lock_held(); \ | |
d9a4af56 | 283 | hlist_for_each_entry(con, &console_list, node) |
a75d946f | 284 | |
9e124fe1 | 285 | extern int console_set_on_cmdline; |
d0380e6c | 286 | extern struct console *early_console; |
9e124fe1 | 287 | |
de6da1e8 FT |
288 | enum con_flush_mode { |
289 | CONSOLE_FLUSH_PENDING, | |
290 | CONSOLE_REPLAY_ALL, | |
291 | }; | |
292 | ||
1da177e4 | 293 | extern int add_preferred_console(char *name, int idx, char *options); |
6f883675 | 294 | extern void console_force_preferred_locked(struct console *con); |
1da177e4 LT |
295 | extern void register_console(struct console *); |
296 | extern int unregister_console(struct console *); | |
ac751efa TH |
297 | extern void console_lock(void); |
298 | extern int console_trylock(void); | |
299 | extern void console_unlock(void); | |
1da177e4 LT |
300 | extern void console_conditional_schedule(void); |
301 | extern void console_unblank(void); | |
de6da1e8 | 302 | extern void console_flush_on_panic(enum con_flush_mode mode); |
1da177e4 LT |
303 | extern struct tty_driver *console_device(int *); |
304 | extern void console_stop(struct console *); | |
305 | extern void console_start(struct console *); | |
306 | extern int is_console_locked(void); | |
f7511d5f ST |
307 | extern int braille_register_console(struct console *, int index, |
308 | char *console_options, char *braille_options); | |
309 | extern int braille_unregister_console(struct console *); | |
4f73bc4d | 310 | #ifdef CONFIG_TTY |
fbc92a34 | 311 | extern void console_sysfs_notify(void); |
4f73bc4d JM |
312 | #else |
313 | static inline void console_sysfs_notify(void) | |
314 | { } | |
315 | #endif | |
90ab5ee9 | 316 | extern bool console_suspend_enabled; |
8f4ce8c3 | 317 | |
557240b4 LT |
318 | /* Suspend and resume console messages over PM events */ |
319 | extern void suspend_console(void); | |
320 | extern void resume_console(void); | |
321 | ||
3cb340ec | 322 | int mda_console_init(void); |
3cb340ec | 323 | |
4995f8ef KS |
324 | void vcs_make_sysfs(int index); |
325 | void vcs_remove_sysfs(int index); | |
1b135431 | 326 | |
1da177e4 | 327 | /* Some debug stub to catch some of the obvious races in the VT code */ |
56e6c104 TZ |
328 | #define WARN_CONSOLE_UNLOCKED() \ |
329 | WARN_ON(!atomic_read(&ignore_console_lock_warning) && \ | |
330 | !is_console_locked() && !oops_in_progress) | |
331 | /* | |
332 | * Increment ignore_console_lock_warning if you need to quiet | |
333 | * WARN_CONSOLE_UNLOCKED() for debugging purposes. | |
334 | */ | |
335 | extern atomic_t ignore_console_lock_warning; | |
1da177e4 LT |
336 | |
337 | /* VESA Blanking Levels */ | |
338 | #define VESA_NO_BLANKING 0 | |
339 | #define VESA_VSYNC_SUSPEND 1 | |
340 | #define VESA_HSYNC_SUSPEND 2 | |
341 | #define VESA_POWERDOWN 3 | |
342 | ||
0c688614 NP |
343 | extern void console_init(void); |
344 | ||
83d83beb HG |
345 | /* For deferred console takeover */ |
346 | void dummycon_register_output_notifier(struct notifier_block *nb); | |
347 | void dummycon_unregister_output_notifier(struct notifier_block *nb); | |
348 | ||
1da177e4 | 349 | #endif /* _LINUX_CONSOLE_H */ |