xref: /openbmc/linux/kernel/printk/internal.h (revision 82e6fdd6)
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	 0x3fffffff
22 #define PRINTK_NMI_DEFERRED_CONTEXT_MASK 0x40000000
23 #define PRINTK_NMI_CONTEXT_MASK		 0x80000000
24 
25 extern raw_spinlock_t logbuf_lock;
26 
27 __printf(1, 0) int vprintk_default(const char *fmt, va_list args);
28 __printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
29 __printf(1, 0) int vprintk_func(const char *fmt, va_list args);
30 void __printk_safe_enter(void);
31 void __printk_safe_exit(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 #define printk_safe_enter_irq()		\
46 	do {					\
47 		local_irq_disable();		\
48 		__printk_safe_enter();		\
49 	} while (0)
50 
51 #define printk_safe_exit_irq()			\
52 	do {					\
53 		__printk_safe_exit();		\
54 		local_irq_enable();		\
55 	} while (0)
56 
57 #else
58 
59 __printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }
60 
61 /*
62  * In !PRINTK builds we still export logbuf_lock spin_lock, console_sem
63  * semaphore and some of console functions (console_unlock()/etc.), so
64  * printk-safe must preserve the existing local IRQ guarantees.
65  */
66 #define printk_safe_enter_irqsave(flags) local_irq_save(flags)
67 #define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
68 
69 #define printk_safe_enter_irq() local_irq_disable()
70 #define printk_safe_exit_irq() local_irq_enable()
71 
72 #endif /* CONFIG_PRINTK */
73