kernel/printk/internal.h

   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 typedef __printf(1, 0) int (*printk_func_t)(const char *fmt, va_list args);
  20
  21 int __printf(1, 0) vprintk_default(const char *fmt, va_list args);
  22
  23 #ifdef CONFIG_PRINTK_NMI
  24
  25 extern 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  */
  33 DECLARE_PER_CPU(printk_func_t, printk_func);
  34 static 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
  39 extern atomic_t nmi_message_lost;
  40 static inline int get_nmi_message_lost(void)
  41 {
  42         return atomic_xchg(&nmi_message_lost, 0);
  43 }
  44
  45 #else /* CONFIG_PRINTK_NMI */
  46
  47 static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
  48 {
  49         return vprintk_default(fmt, args);
  50 }
  51
  52 static inline int get_nmi_message_lost(void)
  53 {
  54         return 0;
  55 }
  56
  57 #endif /* CONFIG_PRINTK_NMI */