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 */