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
19typedef __printf(1, 0) int (*printk_func_t)(const char *fmt, va_list args);
20
21int __printf(1, 0) vprintk_default(const char *fmt, va_list args);
 
 
22
23#ifdef CONFIG_PRINTK_NMI
24
25extern raw_spinlock_t logbuf_lock;
26
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
27/*
28 * printk() could not take logbuf_lock in NMI context. Instead,
29 * it temporary stores the strings into a per-CPU buffer.
30 * The alternative implementation is chosen transparently
31 * via per-CPU variable.
32 */
33DECLARE_PER_CPU(printk_func_t, printk_func);
34static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
35{
36	return this_cpu_read(printk_func)(fmt, args);
37}
38
39extern atomic_t nmi_message_lost;
40static inline int get_nmi_message_lost(void)
41{
42	return atomic_xchg(&nmi_message_lost, 0);
43}
44
45#else /* CONFIG_PRINTK_NMI */
46
47static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
48{
49	return vprintk_default(fmt, args);
50}
51
52static inline int get_nmi_message_lost(void)
53{
54	return 0;
55}
56
57#endif /* CONFIG_PRINTK_NMI */
 
 

 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	0x007ffffff
10#define PRINTK_NMI_DIRECT_CONTEXT_MASK	0x008000000
11#define PRINTK_NMI_CONTEXT_MASK		0xff0000000
12
13#define PRINTK_NMI_CONTEXT_OFFSET	0x010000000
14
15extern raw_spinlock_t logbuf_lock;
16
17__printf(5, 0)
18int vprintk_store(int facility, int level,
19		  const char *dict, size_t dictlen,
20		  const char *fmt, va_list args);
21
22__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
23__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
24__printf(1, 0) int vprintk_func(const char *fmt, va_list args);
25void __printk_safe_enter(void);
26void __printk_safe_exit(void);
27
28void printk_safe_init(void);
29bool printk_percpu_data_ready(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
55void defer_console_output(void);
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
72static inline void printk_safe_init(void) { }
73static inline bool printk_percpu_data_ready(void) { return false; }
74#endif /* CONFIG_PRINTK */