LXR linux/arch/tile/include/asm/spinlock

   1/*
   2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
   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, version 2.
   7 *
   8 *   This program is distributed in the hope that it will be useful, but
   9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11 *   NON INFRINGEMENT.  See the GNU General Public License for
  12 *   more details.
  13 */
  14
  15#ifndef _ASM_TILE_SPINLOCK_TYPES_H
  16#define _ASM_TILE_SPINLOCK_TYPES_H
  17
  18#ifndef __LINUX_SPINLOCK_TYPES_H
  19# error "please don't include this file directly"
  20#endif
  21
  22#ifdef __tilegx__
  23
  24/* Low 15 bits are "next"; high 15 bits are "current". */
  25typedef struct arch_spinlock {
  26        unsigned int lock;
  27} arch_spinlock_t;
  28
  29#define __ARCH_SPIN_LOCK_UNLOCKED       { 0 }
  30
  31/* High bit is "writer owns"; low 31 bits are a count of readers. */
  32typedef struct arch_rwlock {
  33        unsigned int lock;
  34} arch_rwlock_t;
  35
  36#define __ARCH_RW_LOCK_UNLOCKED         { 0 }
  37
  38#else
  39
  40typedef struct arch_spinlock {
  41        /* Next ticket number to hand out. */
  42        int next_ticket;
  43        /* The ticket number that currently owns this lock. */
  44        int current_ticket;
  45} arch_spinlock_t;
  46
  47#define __ARCH_SPIN_LOCK_UNLOCKED       { 0, 0 }
  48
  49/*
  50 * Byte 0 for tns (only the low bit is used), byte 1 for ticket-lock "next",
  51 * byte 2 for ticket-lock "current", byte 3 for reader count.
  52 */
  53typedef struct arch_rwlock {
  54        unsigned int lock;
  55} arch_rwlock_t;
  56
  57#define __ARCH_RW_LOCK_UNLOCKED         { 0 }
  58
  59#endif
  60#endif /* _ASM_TILE_SPINLOCK_TYPES_H */
  61