xref: /openbmc/linux/kernel/printk/internal.h (revision 15e3ae36)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * internal.h - printk internal definitions
4  */
5 #include <linux/percpu.h>
6 
7 #ifdef CONFIG_PRINTK
8 
9 #define PRINTK_SAFE_CONTEXT_MASK	 0x3fffffff
10 #define PRINTK_NMI_DIRECT_CONTEXT_MASK	 0x40000000
11 #define PRINTK_NMI_CONTEXT_MASK		 0x80000000
12 
13 extern raw_spinlock_t logbuf_lock;
14 
15 __printf(5, 0)
16 int vprintk_store(int facility, int level,
17 		  const char *dict, size_t dictlen,
18 		  const char *fmt, va_list args);
19 
20 __printf(1, 0) int vprintk_default(const char *fmt, va_list args);
21 __printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
22 __printf(1, 0) int vprintk_func(const char *fmt, va_list args);
23 void __printk_safe_enter(void);
24 void __printk_safe_exit(void);
25 
26 void printk_safe_init(void);
27 bool printk_percpu_data_ready(void);
28 
29 #define printk_safe_enter_irqsave(flags)	\
30 	do {					\
31 		local_irq_save(flags);		\
32 		__printk_safe_enter();		\
33 	} while (0)
34 
35 #define printk_safe_exit_irqrestore(flags)	\
36 	do {					\
37 		__printk_safe_exit();		\
38 		local_irq_restore(flags);	\
39 	} while (0)
40 
41 #define printk_safe_enter_irq()		\
42 	do {					\
43 		local_irq_disable();		\
44 		__printk_safe_enter();		\
45 	} while (0)
46 
47 #define printk_safe_exit_irq()			\
48 	do {					\
49 		__printk_safe_exit();		\
50 		local_irq_enable();		\
51 	} while (0)
52 
53 void defer_console_output(void);
54 
55 #else
56 
57 __printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }
58 
59 /*
60  * In !PRINTK builds we still export logbuf_lock spin_lock, console_sem
61  * semaphore and some of console functions (console_unlock()/etc.), so
62  * printk-safe must preserve the existing local IRQ guarantees.
63  */
64 #define printk_safe_enter_irqsave(flags) local_irq_save(flags)
65 #define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
66 
67 #define printk_safe_enter_irq() local_irq_disable()
68 #define printk_safe_exit_irq() local_irq_enable()
69 
70 static inline void printk_safe_init(void) { }
71 static inline bool printk_percpu_data_ready(void) { return false; }
72 #endif /* CONFIG_PRINTK */
73