usr/src/uts/intel/sys/mutex_impl.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_MUTEX_IMPL_H
  27 #define _SYS_MUTEX_IMPL_H
  28
  29 #ifndef _ASM
  30 #include <sys/types.h>
  31 #include <sys/machlock.h>
  32 #endif
  33
  34 #ifdef  __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 #ifndef _ASM
  39
  40 /*
  41  * mutex_enter() assumes that the mutex is adaptive and tries to grab the
  42  * lock by doing a atomic compare and exchange on the first word of the mutex.
  43  * If the compare and exchange fails, it means that either (1) the lock is a
  44  * spin lock, or (2) the lock is adaptive but already held.
  45  * mutex_vector_enter() distinguishes these cases by looking at the mutex
  46  * type, which is encoded in the low-order bits of the owner field.
  47  */
  48 typedef union mutex_impl {
  49         /*
  50          * Adaptive mutex.
  51          */
  52         struct adaptive_mutex {
  53                 uintptr_t _m_owner;     /* 0-3/0-7 owner and waiters bit */
  54 #ifndef _LP64
  55                 uintptr_t _m_filler;    /* 4-7 unused */
  56 #endif
  57         } m_adaptive;
  58
  59         /*
  60          * Spin Mutex.
  61          */
  62         struct spin_mutex {
  63                 lock_t  m_dummylock;    /* 0    dummy lock (always set) */
  64                 lock_t  m_spinlock;     /* 1    real lock */
  65                 ushort_t m_filler;      /* 2-3  unused */
  66                 ushort_t m_oldspl;      /* 4-5  old pil value */
  67                 ushort_t m_minspl;      /* 6-7  min pil val if lock held */
  68         } m_spin;
  69
  70 } mutex_impl_t;
  71
  72 #define m_owner m_adaptive._m_owner
  73
  74 #define MUTEX_ALIGN     _LONG_ALIGNMENT
  75 #define MUTEX_ALIGN_WARNINGS    10      /* num of warnings to issue */
  76
  77 #define MUTEX_WAITERS           0x1
  78 #define MUTEX_DEAD              0x6
  79 #define MUTEX_THREAD            (-0x8)
  80
  81 #define MUTEX_OWNER(lp)         ((kthread_id_t)((lp)->m_owner & MUTEX_THREAD))
  82 #define MUTEX_NO_OWNER          ((kthread_id_t)NULL)
  83
  84 #define MUTEX_SET_WAITERS(lp)                                           \
  85 {                                                                       \
  86         uintptr_t old;                                                  \
  87         while ((old = (lp)->m_owner) != 0 &&                            \
  88             casip(&(lp)->m_owner, old, old | MUTEX_WAITERS) != old)     \
  89                 continue;                                               \
  90 }
  91
  92 #define MUTEX_HAS_WAITERS(lp)                   ((lp)->m_owner & MUTEX_WAITERS)
  93 #define MUTEX_CLEAR_LOCK_AND_WAITERS(lp)        (lp)->m_owner = 0
  94
  95 #define MUTEX_SET_TYPE(lp, type)
  96 #define MUTEX_TYPE_ADAPTIVE(lp) (((lp)->m_owner & MUTEX_DEAD) == 0)
  97 #define MUTEX_TYPE_SPIN(lp)     ((lp)->m_spin.m_dummylock == LOCK_HELD_VALUE)
  98
  99 #define MUTEX_DESTROY(lp)       \
 100         (lp)->m_owner = ((uintptr_t)curthread | MUTEX_DEAD)
 101 /* mutex backoff delay macro and constants  */
 102 #define MUTEX_BACKOFF_BASE      1
 103 #define MUTEX_BACKOFF_SHIFT     2
 104 #define MUTEX_CAP_FACTOR        64
 105 #define MUTEX_DELAY()   {       \
 106                         mutex_delay(); \
 107                         SMT_PAUSE();    \
 108                         }
 109
 110 /* low overhead clock read */
 111 #define MUTEX_GETTICK() tsc_read()
 112 extern void null_xcall(void);
 113 #define MUTEX_SYNC()    {       \
 114                         cpuset_t set;   \
 115                         CPUSET_ALL(set);        \
 116                         xc_call(0, 0, 0, CPUSET2BV(set),        \
 117                             (xc_func_t)null_xcall); \
 118                 }
 119
 120 extern int mutex_adaptive_tryenter(mutex_impl_t *);
 121 extern void *mutex_owner_running(mutex_impl_t *);
 122
 123 #else   /* _ASM */
 124
 125 #define MUTEX_THREAD    -0x8
 126
 127 #endif  /* _ASM */
 128
 129 #ifdef  __cplusplus
 130 }
 131 #endif
 132
 133 #endif  /* _SYS_MUTEX_IMPL_H */