lib/librte_eal/common/include/arch/x86/rte_spinlock.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   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  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * 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  *     * Neither the name of Intel Corporation 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 FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #ifndef _RTE_SPINLOCK_X86_64_H_
  35 #define _RTE_SPINLOCK_X86_64_H_
  36
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 #include "generic/rte_spinlock.h"
  42 #include "rte_rtm.h"
  43 #include "rte_cpuflags.h"
  44 #include "rte_branch_prediction.h"
  45 #include "rte_common.h"
  46 #include "rte_pause.h"
  47
  48 #define RTE_RTM_MAX_RETRIES (10)
  49 #define RTE_XABORT_LOCK_BUSY (0xff)
  50
  51 #ifndef RTE_FORCE_INTRINSICS
  52 static inline void
  53 rte_spinlock_lock(rte_spinlock_t *sl)
  54 {
  55         int lock_val = 1;
  56         asm volatile (
  57                         "1:\n"
  58                         "xchg %[locked], %[lv]\n"
  59                         "test %[lv], %[lv]\n"
  60                         "jz 3f\n"
  61                         "2:\n"
  62                         "pause\n"
  63                         "cmpl $0, %[locked]\n"
  64                         "jnz 2b\n"
  65                         "jmp 1b\n"
  66                         "3:\n"
  67                         : [locked] "=m" (sl->locked), [lv] "=q" (lock_val)
  68                         : "[lv]" (lock_val)
  69                         : "memory");
  70 }
  71
  72 static inline void
  73 rte_spinlock_unlock (rte_spinlock_t *sl)
  74 {
  75         int unlock_val = 0;
  76         asm volatile (
  77                         "xchg %[locked], %[ulv]\n"
  78                         : [locked] "=m" (sl->locked), [ulv] "=q" (unlock_val)
  79                         : "[ulv]" (unlock_val)
  80                         : "memory");
  81 }
  82
  83 static inline int
  84 rte_spinlock_trylock (rte_spinlock_t *sl)
  85 {
  86         int lockval = 1;
  87
  88         asm volatile (
  89                         "xchg %[locked], %[lockval]"
  90                         : [locked] "=m" (sl->locked), [lockval] "=q" (lockval)
  91                         : "[lockval]" (lockval)
  92                         : "memory");
  93
  94         return lockval == 0;
  95 }
  96 #endif
  97
  98 extern uint8_t rte_rtm_supported;
  99
 100 static inline int rte_tm_supported(void)
 101 {
 102         return rte_rtm_supported;
 103 }
 104
 105 static inline int
 106 rte_try_tm(volatile int *lock)
 107 {
 108         if (!rte_rtm_supported)
 109                 return 0;
 110
 111         int retries = RTE_RTM_MAX_RETRIES;
 112
 113         while (likely(retries--)) {
 114
 115                 unsigned int status = rte_xbegin();
 116
 117                 if (likely(RTE_XBEGIN_STARTED == status)) {
 118                         if (unlikely(*lock))
 119                                 rte_xabort(RTE_XABORT_LOCK_BUSY);
 120                         else
 121                                 return 1;
 122                 }
 123                 while (*lock)
 124                         rte_pause();
 125
 126                 if ((status & RTE_XABORT_EXPLICIT) &&
 127                         (RTE_XABORT_CODE(status) == RTE_XABORT_LOCK_BUSY))
 128                         continue;
 129
 130                 if ((status & RTE_XABORT_RETRY) == 0) /* do not retry */
 131                         break;
 132         }
 133         return 0;
 134 }
 135
 136 static inline void
 137 rte_spinlock_lock_tm(rte_spinlock_t *sl)
 138 {
 139         if (likely(rte_try_tm(&sl->locked)))
 140                 return;
 141
 142         rte_spinlock_lock(sl); /* fall-back */
 143 }
 144
 145 static inline int
 146 rte_spinlock_trylock_tm(rte_spinlock_t *sl)
 147 {
 148         if (likely(rte_try_tm(&sl->locked)))
 149                 return 1;
 150
 151         return rte_spinlock_trylock(sl);
 152 }
 153
 154 static inline void
 155 rte_spinlock_unlock_tm(rte_spinlock_t *sl)
 156 {
 157         if (unlikely(sl->locked))
 158                 rte_spinlock_unlock(sl);
 159         else
 160                 rte_xend();
 161 }
 162
 163 static inline void
 164 rte_spinlock_recursive_lock_tm(rte_spinlock_recursive_t *slr)
 165 {
 166         if (likely(rte_try_tm(&slr->sl.locked)))
 167                 return;
 168
 169         rte_spinlock_recursive_lock(slr); /* fall-back */
 170 }
 171
 172 static inline void
 173 rte_spinlock_recursive_unlock_tm(rte_spinlock_recursive_t *slr)
 174 {
 175         if (unlikely(slr->sl.locked))
 176                 rte_spinlock_recursive_unlock(slr);
 177         else
 178                 rte_xend();
 179 }
 180
 181 static inline int
 182 rte_spinlock_recursive_trylock_tm(rte_spinlock_recursive_t *slr)
 183 {
 184         if (likely(rte_try_tm(&slr->sl.locked)))
 185                 return 1;
 186
 187         return rte_spinlock_recursive_trylock(slr);
 188 }
 189
 190
 191 #ifdef __cplusplus
 192 }
 193 #endif
 194
 195 #endif /* _RTE_SPINLOCK_X86_64_H_ */