sys/i386/include/lock.h

   1 /*
   2  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $FreeBSD: src/sys/i386/include/lock.h,v 1.11.2.2 2000/09/30 02:49:34 ps Exp $
  35  * $DragonFly: src/sys/i386/include/Attic/lock.h,v 1.10 2004/11/20 20:50:36 dillon Exp $
  36  */
  37
  38 #ifndef _MACHINE_LOCK_H_
  39 #define _MACHINE_LOCK_H_
  40
  41 #ifndef _MACHINE_PSL_H_
  42 #include "psl.h"
  43 #endif
  44
  45 /*
  46  * MP_FREE_LOCK is used by both assembly and C under SMP.
  47  */
  48 #ifdef SMP
  49 #define MP_FREE_LOCK            0xffffffff      /* value of lock when free */
  50 #endif
  51
  52 #ifdef LOCORE
  53
  54 /*
  55  * Spinlock assembly support.  Note: eax and ecx can be tromped.  No
  56  * other register will be.   Note that these routines are sometimes
  57  * called with (%edx) as the mem argument.
  58  *
  59  * Under UP the spinlock routines still serve to disable/restore
  60  * interrupts.
  61  */
  62
  63
  64 #ifdef SMP
  65
  66 #define SPIN_INIT(mem)                                          \
  67         movl    $0,mem ;                                        \
  68
  69 #define SPIN_INIT_NOREG(mem)                                    \
  70         SPIN_INIT(mem) ;                                        \
  71
  72 #define SPIN_LOCK(mem)                                          \
  73         pushfl ;                                                \
  74         popl    %ecx ;          /* flags */                     \
  75         cli ;                                                   \
  76         orl     $PSL_C,%ecx ;   /* make sure non-zero */        \
  77 7: ;                                                            \
  78         movl    $0,%eax ;       /* expected contents of lock */ \
  79         lock cmpxchgl %ecx,mem ; /* Z=1 (jz) on success */      \
  80         pause ;                                                 \
  81         jnz     7b ;                                            \
  82
  83 #define SPIN_LOCK_PUSH_REGS                                     \
  84         subl    $8,%esp ;                                       \
  85         movl    %ecx,(%esp) ;                                   \
  86         movl    %eax,4(%esp) ;                                  \
  87
  88 #define SPIN_LOCK_POP_REGS                                      \
  89         movl    (%esp),%ecx ;                                   \
  90         movl    4(%esp),%eax ;                                  \
  91         addl    $8,%esp ;                                       \
  92
  93 #define SPIN_LOCK_FRAME_SIZE    8
  94
  95 #define SPIN_LOCK_NOREG(mem)                                    \
  96         SPIN_LOCK_PUSH_REGS ;                                   \
  97         SPIN_LOCK(mem) ;                                        \
  98         SPIN_LOCK_POP_REGS ;                                    \
  99
 100 #define SPIN_UNLOCK(mem)                                        \
 101         pushl   mem ;                                           \
 102         movl    $0,mem ;                                        \
 103         popfl ;                                                 \
 104
 105 #define SPIN_UNLOCK_PUSH_REGS
 106 #define SPIN_UNLOCK_POP_REGS
 107 #define SPIN_UNLOCK_FRAME_SIZE  0
 108
 109 #define SPIN_UNLOCK_NOREG(mem)                                  \
 110         SPIN_UNLOCK(mem) ;                                      \
 111
 112 #else
 113
 114 #define SPIN_LOCK(mem)                                          \
 115         pushfl ;                                                \
 116         cli ;                                                   \
 117         orl     $PSL_C,(%esp) ;                                 \
 118         popl    mem ;                                           \
 119
 120 #define SPIN_LOCK_PUSH_RESG
 121 #define SPIN_LOCK_POP_REGS
 122 #define SPIN_LOCK_FRAME_SIZE    0
 123
 124 #define SPIN_UNLOCK(mem)                                        \
 125         pushl   mem ;                                           \
 126         movl    $0,mem ;                                        \
 127         popfl ;                                                 \
 128
 129 #define SPIN_UNLOCK_PUSH_REGS
 130 #define SPIN_UNLOCK_POP_REGS
 131 #define SPIN_UNLOCK_FRAME_SIZE  0
 132
 133 #endif  /* SMP */
 134
 135 #else   /* !LOCORE */
 136
 137 #ifdef _KERNEL
 138
 139 /*
 140  * Spinlock functions (UP and SMP).  Under UP a spinlock still serves
 141  * to disable/restore interrupts even if it doesn't spin.
 142  */
 143 struct spinlock {
 144         volatile int    opaque;
 145 };
 146
 147 typedef struct spinlock *spinlock_t;
 148
 149 void    mpintr_lock(void);      /* disables int / spinlock combo */
 150 void    mpintr_unlock(void);
 151 void    com_lock(void);         /* disables int / spinlock combo */
 152 void    com_unlock(void);
 153 void    imen_lock(void);        /* disables int / spinlock combo */
 154 void    imen_unlock(void);
 155 void    clock_lock(void);       /* disables int / spinlock combo */
 156 void    clock_unlock(void);
 157 void    cons_lock(void);        /* disables int / spinlock combo */
 158 void    cons_unlock(void);
 159
 160 extern struct spinlock smp_rv_spinlock;
 161
 162 void    spin_lock(spinlock_t lock);
 163 void    spin_lock_np(spinlock_t lock);
 164 void    spin_unlock(spinlock_t lock);
 165 void    spin_unlock_np(spinlock_t lock);
 166 #if 0
 167 void    spin_lock_init(spinlock_t lock);
 168 #endif
 169
 170 /*
 171  * Inline version of spinlock routines -- overrides assembly.  Only unlock
 172  * and init here please.
 173  */
 174 static __inline void
 175 spin_lock_init(spinlock_t lock)
 176 {
 177         lock->opaque = 0;
 178 }
 179
 180 #endif  /* _KERNEL */
 181
 182 #if defined(_KERNEL) || defined(_UTHREAD)
 183
 184 /*
 185  * MP LOCK functions for SMP and UP.  Under UP the MP lock does not exist
 186  * but we leave a few functions intact as macros for convenience.
 187  */
 188 #ifdef SMP
 189
 190 void    get_mplock(void);
 191 int     try_mplock(void);
 192 void    rel_mplock(void);
 193 int     cpu_try_mplock(void);
 194 void    cpu_get_initial_mplock(void);
 195
 196 extern u_int    mp_lock;
 197
 198 #define MP_LOCK_HELD()   (mp_lock == mycpu->gd_cpuid)
 199 #define ASSERT_MP_LOCK_HELD()   KKASSERT(MP_LOCK_HELD())
 200
 201 static __inline void
 202 cpu_rel_mplock(void)
 203 {
 204         mp_lock = MP_FREE_LOCK;
 205 }
 206
 207 #else
 208
 209 #define get_mplock()
 210 #define try_mplock()    1
 211 #define rel_mplock()
 212 #define ASSERT_MP_LOCK_HELD()
 213
 214 #endif  /* SMP */
 215 #endif  /* _KERNEL || _UTHREAD */
 216 #endif  /* LOCORE */
 217 #endif  /* !_MACHINE_LOCK_H_ */