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 #define __ARCH_SPIN_LOCK_UNLOCKED_VAL   0x1a46
   6
   7 #define SPINLOCK_BREAK_INSN     0x0000c006      /* break 6,6 */
   8
   9 #ifndef __ASSEMBLY__
  10
  11 typedef struct {
  12         volatile unsigned int lock[4];
  13 # define __ARCH_SPIN_LOCK_UNLOCKED      \
  14         { { __ARCH_SPIN_LOCK_UNLOCKED_VAL, __ARCH_SPIN_LOCK_UNLOCKED_VAL, \
  15             __ARCH_SPIN_LOCK_UNLOCKED_VAL, __ARCH_SPIN_LOCK_UNLOCKED_VAL } }
  16 } arch_spinlock_t;
  17
  18
  19 /* counter:
  20  * Unlocked     : 0x0100_0000
  21  * Read lock(s) : 0x00FF_FFFF to 0x01  (Multiple Readers decrement it)
  22  * Write lock   : 0x0, but only if prior value is "unlocked" 0x0100_0000
  23  */
  24 typedef struct {
  25         arch_spinlock_t         lock_mutex;
  26         volatile unsigned int   counter;
  27 } arch_rwlock_t;
  28
  29 #endif /* __ASSEMBLY__ */
  30
  31 #define __ARCH_RW_LOCK_UNLOCKED__       0x01000000
  32 #define __ARCH_RW_LOCK_UNLOCKED         { .lock_mutex = __ARCH_SPIN_LOCK_UNLOCKED, \
  33                                         .counter = __ARCH_RW_LOCK_UNLOCKED__ }
  34
  35 #endif