sys/platform/pc64/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/platform/pc32/include/lock.h,v 1.17 2008/06/19 21:32:55 aggelos Exp $
  36  */
  37
  38 #ifndef _MACHINE_LOCK_H_
  39 #define _MACHINE_LOCK_H_
  40
  41 #ifndef _CPU_PSL_H_
  42 #include <machine/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: rax and rcx 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         movq    $0,mem ;                                        \
  68
  69 #define SPIN_INIT_NOREG(mem)                                    \
  70         SPIN_INIT(mem) ;                                        \
  71
  72 #define SPIN_LOCK(mem)                                          \
  73         pushfq ;                                                \
  74         popq    %rcx ;          /* flags */                     \
  75         cli ;                                                   \
  76         orq     $PSL_C,%rcx ;   /* make sure non-zero */        \
  77 7: ;                                                            \
  78         movq    $0,%rax ;       /* expected contents of lock */ \
  79         lock cmpxchgq %rcx,mem ; /* Z=1 (jz) on success */      \
  80         pause ;                                                 \
  81         jnz     7b ;                                            \
  82
  83 #define SPIN_LOCK_PUSH_REGS                                     \
  84         subq    $16,%rsp ;                                      \
  85         movq    %rcx,(%rsp) ;                                   \
  86         movq    %rax,8(%rsp) ;                                  \
  87
  88 #define SPIN_LOCK_POP_REGS                                      \
  89         movq    (%rsp),%rcx ;                                   \
  90         movq    8(%rsp),%rax ;                                  \
  91         addq    $16,%rsp ;                                      \
  92
  93 #define SPIN_LOCK_FRAME_SIZE    16
  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         pushq   mem ;                                           \
 102         movq    $0,mem ;                                        \
 103         popfq ;                                                 \
 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 /* !SMP */
 113
 114 #define SPIN_LOCK(mem)                                          \
 115         pushfq ;                                                \
 116         cli ;                                                   \
 117         orq     $PSL_C,(%rsp) ;                                 \
 118         popq    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         pushq   mem ;                                           \
 126         movq    $0,mem ;                                        \
 127         popfq ;                                                 \
 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_deprecated {
 144         volatile long   opaque;
 145 };
 146
 147 typedef struct spinlock_deprecated *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
 158 extern struct spinlock_deprecated smp_rv_spinlock;
 159
 160 void    spin_lock_deprecated(spinlock_t lock);
 161 void    spin_unlock_deprecated(spinlock_t lock);
 162
 163 /*
 164  * Inline version of spinlock routines -- overrides assembly.  Only unlock
 165  * and init here please.
 166  */
 167 static __inline void
 168 spin_lock_init(spinlock_t lock)
 169 {
 170         lock->opaque = 0;
 171 }
 172
 173 #endif  /* _KERNEL */
 174
 175 #if defined(_KERNEL) || defined(_UTHREAD)
 176
 177 /*
 178  * MP LOCK functions for SMP and UP.  Under UP the MP lock does not exist
 179  * but we leave a few functions intact as macros for convenience.
 180  */
 181 #ifdef SMP
 182
 183 void    get_mplock(void);
 184 int     try_mplock(void);
 185 void    rel_mplock(void);
 186 int     cpu_try_mplock(void);
 187 void    cpu_get_initial_mplock(void);
 188
 189 extern u_int    mp_lock;
 190
 191 #define MP_LOCK_HELD()   (mp_lock == mycpu->gd_cpuid)
 192 #define ASSERT_MP_LOCK_HELD(td)   KASSERT(MP_LOCK_HELD(), ("MP_LOCK_HELD(): not held thread %p", td))
 193
 194 static __inline void
 195 cpu_rel_mplock(void)
 196 {
 197         mp_lock = MP_FREE_LOCK;
 198 }
 199
 200 static __inline int
 201 owner_mplock(void)
 202 {
 203         return (mp_lock);
 204 }
 205
 206 #else /* !SMP */
 207
 208 #define get_mplock()
 209 #define try_mplock()    1
 210 #define rel_mplock()
 211 #define owner_mplock()  0       /* always cpu 0 */
 212 #define MP_LOCK_HELD()  (!0)
 213 #define ASSERT_MP_LOCK_HELD(td)
 214
 215 #endif  /* SMP */
 216 #endif  /* _KERNEL || _UTHREAD */
 217 #endif  /* LOCORE */
 218 #endif  /* !_MACHINE_LOCK_H_ */