sys/platform/pc32/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  */
  36
  37 #ifndef _MACHINE_LOCK_H_
  38 #define _MACHINE_LOCK_H_
  39
  40 #ifndef _CPU_PSL_H_
  41 #include <machine/psl.h>
  42 #endif
  43
  44 #ifdef LOCORE
  45
  46 /*
  47  * Spinlock assembly support.  Note: eax and ecx can be tromped.  No
  48  * other register will be.   Note that these routines are sometimes
  49  * called with (%edx) as the mem argument.
  50  *
  51  * Under UP the spinlock routines still serve to disable/restore
  52  * interrupts.
  53  */
  54 #define SPIN_INIT(mem)                                          \
  55         movl    $0,mem ;                                        \
  56
  57 #define SPIN_INIT_NOREG(mem)                                    \
  58         SPIN_INIT(mem) ;                                        \
  59
  60 #define SPIN_LOCK(mem)                                          \
  61         pushfl ;                                                \
  62         popl    %ecx ;          /* flags */                     \
  63         cli ;                                                   \
  64         orl     $PSL_C,%ecx ;   /* make sure non-zero */        \
  65 7: ;                                                            \
  66         movl    $0,%eax ;       /* expected contents of lock */ \
  67         lock cmpxchgl %ecx,mem ; /* Z=1 (jz) on success */      \
  68         pause ;                                                 \
  69         jnz     7b ;                                            \
  70
  71 #define SPIN_LOCK_PUSH_REGS                                     \
  72         subl    $8,%esp ;                                       \
  73         movl    %ecx,(%esp) ;                                   \
  74         movl    %eax,4(%esp) ;                                  \
  75
  76 #define SPIN_LOCK_POP_REGS                                      \
  77         movl    (%esp),%ecx ;                                   \
  78         movl    4(%esp),%eax ;                                  \
  79         addl    $8,%esp ;                                       \
  80
  81 #define SPIN_LOCK_FRAME_SIZE    8
  82
  83 #define SPIN_LOCK_NOREG(mem)                                    \
  84         SPIN_LOCK_PUSH_REGS ;                                   \
  85         SPIN_LOCK(mem) ;                                        \
  86         SPIN_LOCK_POP_REGS ;                                    \
  87
  88 #define SPIN_UNLOCK(mem)                                        \
  89         pushl   mem ;                                           \
  90         movl    $0,mem ;                                        \
  91         popfl ;                                                 \
  92
  93 #define SPIN_UNLOCK_PUSH_REGS
  94 #define SPIN_UNLOCK_POP_REGS
  95 #define SPIN_UNLOCK_FRAME_SIZE  0
  96
  97 #define SPIN_UNLOCK_NOREG(mem)                                  \
  98         SPIN_UNLOCK(mem) ;                                      \
  99
 100 #else   /* !LOCORE */
 101
 102 #ifdef _KERNEL
 103
 104 /*
 105  * Spinlock functions (UP and SMP).  Under UP a spinlock still serves
 106  * to disable/restore interrupts even if it doesn't spin.
 107  */
 108 struct spinlock_deprecated {
 109         volatile int    opaque;
 110 };
 111
 112 typedef struct spinlock_deprecated *spinlock_t;
 113
 114 void    mpintr_lock(void);      /* disables int / spinlock combo */
 115 void    mpintr_unlock(void);
 116 void    com_lock(void);         /* disables int / spinlock combo */
 117 void    com_unlock(void);
 118 void    imen_lock(void);        /* disables int / spinlock combo */
 119 void    imen_unlock(void);
 120 void    clock_lock(void);       /* disables int / spinlock combo */
 121 void    clock_unlock(void);
 122
 123 void    spin_lock_deprecated(spinlock_t lock);
 124 void    spin_unlock_deprecated(spinlock_t lock);
 125
 126 /*
 127  * Inline version of spinlock routines -- overrides assembly.  Only unlock
 128  * and init here please.
 129  */
 130 static __inline void
 131 spin_lock_init(spinlock_t lock)
 132 {
 133         lock->opaque = 0;
 134 }
 135
 136 #endif  /* _KERNEL */
 137
 138 #endif  /* LOCORE */
 139 #endif  /* !_MACHINE_LOCK_H_ */