arch/parisc/include/asm/spinlock_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_SPINLOCK_TYPES_H
   3 #define __ASM_SPINLOCK_TYPES_H
   4
   5 typedef struct {
   6         volatile unsigned int lock[4];
   7 # define __ARCH_SPIN_LOCK_UNLOCKED      { { 1, 1, 1, 1 } }
   8 } arch_spinlock_t;
   9
  10
  11 /* counter:
  12  * Unlocked     : 0x0100_0000
  13  * Read lock(s) : 0x00FF_FFFF to 0x01  (Multiple Readers decrement it)
  14  * Write lock   : 0x0, but only if prior value is "unlocked" 0x0100_0000
  15  */
  16 typedef struct {
  17         arch_spinlock_t         lock_mutex;
  18         volatile unsigned int   counter;
  19 } arch_rwlock_t;
  20
  21 #define __ARCH_RW_LOCK_UNLOCKED__       0x01000000
  22 #define __ARCH_RW_LOCK_UNLOCKED         { .lock_mutex = __ARCH_SPIN_LOCK_UNLOCKED, \
  23                                         .counter = __ARCH_RW_LOCK_UNLOCKED__ }
  24
  25 #endif