| /* |
| * linux/include/linux/console.h |
| * |
| * Copyright (C) 1993 Hamish Macdonald |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file COPYING in the main directory of this archive |
| * for more details. |
| * |
| * Changed: |
| * 10-Mar-94: Arno Griffioen: Conversion for vt100 emulator port from PC LINUX |
| */ |
| |
| #ifndef _LINUX_CONSOLE_H_ |
| #define _LINUX_CONSOLE_H_ 1 |
| |
| #include <linux/atomic.h> |
| #include <linux/rculist.h> |
| #include <linux/types.h> |
| |
| struct vc_data; |
| struct console_font_op; |
| struct console_font; |
| struct module; |
| struct tty_struct; |
| struct notifier_block; |
| |
| enum con_scroll { |
| SM_UP, |
| SM_DOWN, |
| }; |
| |
| enum vc_intensity; |
| |
| /** |
| * struct consw - callbacks for consoles |
| * |
| * @con_scroll: move lines from @top to @bottom in direction @dir by @lines. |
| * Return true if no generic handling should be done. |
| * Invoked by csi_M and printing to the console. |
| * @con_set_palette: sets the palette of the console to @table (optional) |
| * @con_scrolldelta: the contents of the console should be scrolled by @lines. |
| * Invoked by user. (optional) |
| */ |
| struct consw { |
| struct module *owner; |
| const char *(*con_startup)(void); |
| void (*con_init)(struct vc_data *vc, int init); |
| void (*con_deinit)(struct vc_data *vc); |
| void (*con_clear)(struct vc_data *vc, int sy, int sx, int height, |
| int width); |
| void (*con_putc)(struct vc_data *vc, int c, int ypos, int xpos); |
| void (*con_putcs)(struct vc_data *vc, const unsigned short *s, |
| int count, int ypos, int xpos); |
| void (*con_cursor)(struct vc_data *vc, int mode); |
| bool (*con_scroll)(struct vc_data *vc, unsigned int top, |
| unsigned int bottom, enum con_scroll dir, |
| unsigned int lines); |
| int (*con_switch)(struct vc_data *vc); |
| int (*con_blank)(struct vc_data *vc, int blank, int mode_switch); |
| int (*con_font_set)(struct vc_data *vc, struct console_font *font, |
| unsigned int flags); |
| int (*con_font_get)(struct vc_data *vc, struct console_font *font); |
| int (*con_font_default)(struct vc_data *vc, |
| struct console_font *font, char *name); |
| int (*con_resize)(struct vc_data *vc, unsigned int width, |
| unsigned int height, unsigned int user); |
| void (*con_set_palette)(struct vc_data *vc, |
| const unsigned char *table); |
| void (*con_scrolldelta)(struct vc_data *vc, int lines); |
| int (*con_set_origin)(struct vc_data *vc); |
| void (*con_save_screen)(struct vc_data *vc); |
| u8 (*con_build_attr)(struct vc_data *vc, u8 color, |
| enum vc_intensity intensity, |
| bool blink, bool underline, bool reverse, bool italic); |
| void (*con_invert_region)(struct vc_data *vc, u16 *p, int count); |
| u16 *(*con_screen_pos)(const struct vc_data *vc, int offset); |
| unsigned long (*con_getxy)(struct vc_data *vc, unsigned long position, |
| int *px, int *py); |
| /* |
| * Flush the video console driver's scrollback buffer |
| */ |
| void (*con_flush_scrollback)(struct vc_data *vc); |
| /* |
| * Prepare the console for the debugger. This includes, but is not |
| * limited to, unblanking the console, loading an appropriate |
| * palette, and allowing debugger generated output. |
| */ |
| int (*con_debug_enter)(struct vc_data *vc); |
| /* |
| * Restore the console to its pre-debug state as closely as possible. |
| */ |
| int (*con_debug_leave)(struct vc_data *vc); |
| }; |
| |
| extern const struct consw *conswitchp; |
| |
| extern const struct consw dummy_con; /* dummy console buffer */ |
| extern const struct consw vga_con; /* VGA text console */ |
| extern const struct consw newport_con; /* SGI Newport console */ |
| |
| int con_is_bound(const struct consw *csw); |
| int do_unregister_con_driver(const struct consw *csw); |
| int do_take_over_console(const struct consw *sw, int first, int last, int deflt); |
| void give_up_console(const struct consw *sw); |
| #ifdef CONFIG_HW_CONSOLE |
| int con_debug_enter(struct vc_data *vc); |
| int con_debug_leave(void); |
| #else |
| static inline int con_debug_enter(struct vc_data *vc) |
| { |
| return 0; |
| } |
| static inline int con_debug_leave(void) |
| { |
| return 0; |
| } |
| #endif |
| |
| /* cursor */ |
| #define CM_DRAW (1) |
| #define CM_ERASE (2) |
| #define CM_MOVE (3) |
| |
| /* |
| * The interface for a console, or any other device that wants to capture |
| * console messages (printer driver?) |
| * |
| * If a console driver is marked CON_BOOT then it will be auto-unregistered |
| * when the first real console is registered. This is for early-printk drivers. |
| */ |
| |
| #define CON_PRINTBUFFER (1) |
| #define CON_CONSDEV (2) /* Preferred console, /dev/console */ |
| #define CON_ENABLED (4) |
| #define CON_BOOT (8) |
| #define CON_ANYTIME (16) /* Safe to call when cpu is offline */ |
| #define CON_BRL (32) /* Used for a braille device */ |
| #define CON_EXTENDED (64) /* Use the extended output format a la /dev/kmsg */ |
| |
| struct console { |
| char name[16]; |
| void (*write)(struct console *, const char *, unsigned); |
| int (*read)(struct console *, char *, unsigned); |
| struct tty_driver *(*device)(struct console *, int *); |
| void (*unblank)(void); |
| int (*setup)(struct console *, char *); |
| int (*exit)(struct console *); |
| int (*match)(struct console *, char *name, int idx, char *options); |
| short flags; |
| short index; |
| int cflag; |
| uint ispeed; |
| uint ospeed; |
| u64 seq; |
| unsigned long dropped; |
| void *data; |
| struct hlist_node node; |
| }; |
| |
| #ifdef CONFIG_LOCKDEP |
| extern void lockdep_assert_console_list_lock_held(void); |
| #else |
| static inline void lockdep_assert_console_list_lock_held(void) |
| { |
| } |
| #endif |
| |
| #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| extern bool console_srcu_read_lock_is_held(void); |
| #else |
| static inline bool console_srcu_read_lock_is_held(void) |
| { |
| return 1; |
| } |
| #endif |
| |
| extern int console_srcu_read_lock(void); |
| extern void console_srcu_read_unlock(int cookie); |
| |
| extern void console_list_lock(void) __acquires(console_mutex); |
| extern void console_list_unlock(void) __releases(console_mutex); |
| |
| extern struct hlist_head console_list; |
| |
| /** |
| * console_srcu_read_flags - Locklessly read the console flags |
| * @con: struct console pointer of console to read flags from |
| * |
| * This function provides the necessary READ_ONCE() and data_race() |
| * notation for locklessly reading the console flags. The READ_ONCE() |
| * in this function matches the WRITE_ONCE() when @flags are modified |
| * for registered consoles with console_srcu_write_flags(). |
| * |
| * Only use this function to read console flags when locklessly |
| * iterating the console list via srcu. |
| * |
| * Context: Any context. |
| */ |
| static inline short console_srcu_read_flags(const struct console *con) |
| { |
| WARN_ON_ONCE(!console_srcu_read_lock_is_held()); |
| |
| /* |
| * Locklessly reading console->flags provides a consistent |
| * read value because there is at most one CPU modifying |
| * console->flags and that CPU is using only read-modify-write |
| * operations to do so. |
| */ |
| return data_race(READ_ONCE(con->flags)); |
| } |
| |
| /** |
| * console_srcu_write_flags - Write flags for a registered console |
| * @con: struct console pointer of console to write flags to |
| * @flags: new flags value to write |
| * |
| * Only use this function to write flags for registered consoles. It |
| * requires holding the console_list_lock. |
| * |
| * Context: Any context. |
| */ |
| static inline void console_srcu_write_flags(struct console *con, short flags) |
| { |
| lockdep_assert_console_list_lock_held(); |
| |
| /* This matches the READ_ONCE() in console_srcu_read_flags(). */ |
| WRITE_ONCE(con->flags, flags); |
| } |
| |
| /* Variant of console_is_registered() when the console_list_lock is held. */ |
| static inline bool console_is_registered_locked(const struct console *con) |
| { |
| lockdep_assert_console_list_lock_held(); |
| return !hlist_unhashed(&con->node); |
| } |
| |
| /* |
| * console_is_registered - Check if the console is registered |
| * @con: struct console pointer of console to check |
| * |
| * Context: Process context. May sleep while acquiring console list lock. |
| * Return: true if the console is in the console list, otherwise false. |
| * |
| * If false is returned for a console that was previously registered, it |
| * can be assumed that the console's unregistration is fully completed, |
| * including the exit() callback after console list removal. |
| */ |
| static inline bool console_is_registered(const struct console *con) |
| { |
| bool ret; |
| |
| console_list_lock(); |
| ret = console_is_registered_locked(con); |
| console_list_unlock(); |
| return ret; |
| } |
| |
| /** |
| * for_each_console_srcu() - Iterator over registered consoles |
| * @con: struct console pointer used as loop cursor |
| * |
| * Although SRCU guarantees the console list will be consistent, the |
| * struct console fields may be updated by other CPUs while iterating. |
| * |
| * Requires console_srcu_read_lock to be held. Can be invoked from |
| * any context. |
| */ |
| #define for_each_console_srcu(con) \ |
| hlist_for_each_entry_srcu(con, &console_list, node, \ |
| console_srcu_read_lock_is_held()) |
| |
| /** |
| * for_each_console() - Iterator over registered consoles |
| * @con: struct console pointer used as loop cursor |
| * |
| * The console list and the console->flags are immutable while iterating. |
| * |
| * Requires console_list_lock to be held. |
| */ |
| #define for_each_console(con) \ |
| lockdep_assert_console_list_lock_held(); \ |
| hlist_for_each_entry(con, &console_list, node) |
| |
| extern int console_set_on_cmdline; |
| extern struct console *early_console; |
| |
| enum con_flush_mode { |
| CONSOLE_FLUSH_PENDING, |
| CONSOLE_REPLAY_ALL, |
| }; |
| |
| extern int add_preferred_console(char *name, int idx, char *options); |
| extern void console_force_preferred_locked(struct console *con); |
| extern void register_console(struct console *); |
| extern int unregister_console(struct console *); |
| extern void console_lock(void); |
| extern int console_trylock(void); |
| extern void console_unlock(void); |
| extern void console_conditional_schedule(void); |
| extern void console_unblank(void); |
| extern void console_flush_on_panic(enum con_flush_mode mode); |
| extern struct tty_driver *console_device(int *); |
| extern void console_stop(struct console *); |
| extern void console_start(struct console *); |
| extern int is_console_locked(void); |
| extern int braille_register_console(struct console *, int index, |
| char *console_options, char *braille_options); |
| extern int braille_unregister_console(struct console *); |
| #ifdef CONFIG_TTY |
| extern void console_sysfs_notify(void); |
| #else |
| static inline void console_sysfs_notify(void) |
| { } |
| #endif |
| extern bool console_suspend_enabled; |
| |
| /* Suspend and resume console messages over PM events */ |
| extern void suspend_console(void); |
| extern void resume_console(void); |
| |
| int mda_console_init(void); |
| |
| void vcs_make_sysfs(int index); |
| void vcs_remove_sysfs(int index); |
| |
| /* Some debug stub to catch some of the obvious races in the VT code */ |
| #define WARN_CONSOLE_UNLOCKED() \ |
| WARN_ON(!atomic_read(&ignore_console_lock_warning) && \ |
| !is_console_locked() && !oops_in_progress) |
| /* |
| * Increment ignore_console_lock_warning if you need to quiet |
| * WARN_CONSOLE_UNLOCKED() for debugging purposes. |
| */ |
| extern atomic_t ignore_console_lock_warning; |
| |
| /* VESA Blanking Levels */ |
| #define VESA_NO_BLANKING 0 |
| #define VESA_VSYNC_SUSPEND 1 |
| #define VESA_HSYNC_SUSPEND 2 |
| #define VESA_POWERDOWN 3 |
| |
| extern void console_init(void); |
| |
| /* For deferred console takeover */ |
| void dummycon_register_output_notifier(struct notifier_block *nb); |
| void dummycon_unregister_output_notifier(struct notifier_block *nb); |
| |
| #endif /* _LINUX_CONSOLE_H */ |