xref: /linux/kernel/printk/internal.h (revision 83bce9c2baa51e439480a713119a73d3c8b61083)
1 /*
2  * internal.h - printk internal definitions
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17 #include <linux/percpu.h>
18 
19 #ifdef CONFIG_PRINTK
20 
21 #define PRINTK_SAFE_CONTEXT_MASK	0x7fffffff
22 #define PRINTK_NMI_CONTEXT_MASK	0x80000000
23 
24 extern raw_spinlock_t logbuf_lock;
25 
26 __printf(1, 0) int vprintk_default(const char *fmt, va_list args);
27 __printf(1, 0) int vprintk_func(const char *fmt, va_list args);
28 void __printk_safe_enter(void);
29 void __printk_safe_exit(void);
30 
31 #define printk_safe_enter_irqsave(flags)	\
32 	do {					\
33 		local_irq_save(flags);		\
34 		__printk_safe_enter();		\
35 	} while (0)
36 
37 #define printk_safe_exit_irqrestore(flags)	\
38 	do {					\
39 		__printk_safe_exit();		\
40 		local_irq_restore(flags);	\
41 	} while (0)
42 
43 #define printk_safe_enter_irq()		\
44 	do {					\
45 		local_irq_disable();		\
46 		__printk_safe_enter();		\
47 	} while (0)
48 
49 #define printk_safe_exit_irq()			\
50 	do {					\
51 		__printk_safe_exit();		\
52 		local_irq_enable();		\
53 	} while (0)
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 #endif /* CONFIG_PRINTK */
71