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(2, 0) int (*printk_func_t)(int level, const char *fmt,
  20                                             va_list args);
  21
  22 __printf(2, 0)
  23 int vprintk_default(int level, const char *fmt, va_list args);
  24
  25 #ifdef CONFIG_PRINTK_NMI
  26
  27 extern raw_spinlock_t logbuf_lock;
  28
  29 /*
  30  * printk() could not take logbuf_lock in NMI context. Instead,
  31  * it temporary stores the strings into a per-CPU buffer.
  32  * The alternative implementation is chosen transparently
  33  * via per-CPU variable.
  34  */
  35 DECLARE_PER_CPU(printk_func_t, printk_func);
  36 __printf(2, 0)
  37 static inline int vprintk_func(int level, const char *fmt, va_list args)
  38 {
  39         return this_cpu_read(printk_func)(level, fmt, args);
  40 }
  41
  42 extern atomic_t nmi_message_lost;
  43 static inline int get_nmi_message_lost(void)
  44 {
  45         return atomic_xchg(&nmi_message_lost, 0);
  46 }
  47
  48 #else /* CONFIG_PRINTK_NMI */
  49
  50 __printf(2, 0)
  51 static inline int vprintk_func(int level, const char *fmt, va_list args)
  52 {
  53         return vprintk_default(level, fmt, args);
  54 }
  55
  56 static inline int get_nmi_message_lost(void)
  57 {
  58         return 0;
  59 }
  60
  61 #endif /* CONFIG_PRINTK_NMI */