xref: /linux/kernel/printk/internal.h (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * internal.h - printk internal definitions
4  */
5 #include <linux/percpu.h>
6 
7 #if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
8 void __init printk_sysctl_init(void);
9 int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
10 			      void *buffer, size_t *lenp, loff_t *ppos);
11 #else
12 #define printk_sysctl_init() do { } while (0)
13 #endif
14 
15 #ifdef CONFIG_PRINTK
16 
17 /* Flags for a single printk record. */
18 enum printk_info_flags {
19 	LOG_NEWLINE	= 2,	/* text ended with a newline */
20 	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
21 };
22 
23 __printf(4, 0)
24 int vprintk_store(int facility, int level,
25 		  const struct dev_printk_info *dev_info,
26 		  const char *fmt, va_list args);
27 
28 __printf(1, 0) int vprintk_default(const char *fmt, va_list args);
29 __printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
30 
31 bool printk_percpu_data_ready(void);
32 
33 #define printk_safe_enter_irqsave(flags)	\
34 	do {					\
35 		local_irq_save(flags);		\
36 		__printk_safe_enter();		\
37 	} while (0)
38 
39 #define printk_safe_exit_irqrestore(flags)	\
40 	do {					\
41 		__printk_safe_exit();		\
42 		local_irq_restore(flags);	\
43 	} while (0)
44 
45 void defer_console_output(void);
46 
47 u16 printk_parse_prefix(const char *text, int *level,
48 			enum printk_info_flags *flags);
49 #else
50 
51 /*
52  * In !PRINTK builds we still export console_sem
53  * semaphore and some of console functions (console_unlock()/etc.), so
54  * printk-safe must preserve the existing local IRQ guarantees.
55  */
56 #define printk_safe_enter_irqsave(flags) local_irq_save(flags)
57 #define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
58 
59 static inline bool printk_percpu_data_ready(void) { return false; }
60 #endif /* CONFIG_PRINTK */
61