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

   1 /*-
   2  *   BSD LICENSE
   3  *
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  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         int retries;
 109
 110         if (!rte_rtm_supported)
 111                 return 0;
 112
 113         retries = RTE_RTM_MAX_RETRIES;
 114
 115         while (likely(retries--)) {
 116
 117                 unsigned int status = rte_xbegin();
 118
 119                 if (likely(RTE_XBEGIN_STARTED == status)) {
 120                         if (unlikely(*lock))
 121                                 rte_xabort(RTE_XABORT_LOCK_BUSY);
 122                         else
 123                                 return 1;
 124                 }
 125                 while (*lock)
 126                         rte_pause();
 127
 128                 if ((status & RTE_XABORT_EXPLICIT) &&
 129                         (RTE_XABORT_CODE(status) == RTE_XABORT_LOCK_BUSY))
 130                         continue;
 131
 132                 if ((status & RTE_XABORT_RETRY) == 0) /* do not retry */
 133                         break;
 134         }
 135         return 0;
 136 }
 137
 138 static inline void
 139 rte_spinlock_lock_tm(rte_spinlock_t *sl)
 140 {
 141         if (likely(rte_try_tm(&sl->locked)))
 142                 return;
 143
 144         rte_spinlock_lock(sl); /* fall-back */
 145 }
 146
 147 static inline int
 148 rte_spinlock_trylock_tm(rte_spinlock_t *sl)
 149 {
 150         if (likely(rte_try_tm(&sl->locked)))
 151                 return 1;
 152
 153         return rte_spinlock_trylock(sl);
 154 }
 155
 156 static inline void
 157 rte_spinlock_unlock_tm(rte_spinlock_t *sl)
 158 {
 159         if (unlikely(sl->locked))
 160                 rte_spinlock_unlock(sl);
 161         else
 162                 rte_xend();
 163 }
 164
 165 static inline void
 166 rte_spinlock_recursive_lock_tm(rte_spinlock_recursive_t *slr)
 167 {
 168         if (likely(rte_try_tm(&slr->sl.locked)))
 169                 return;
 170
 171         rte_spinlock_recursive_lock(slr); /* fall-back */
 172 }
 173
 174 static inline void
 175 rte_spinlock_recursive_unlock_tm(rte_spinlock_recursive_t *slr)
 176 {
 177         if (unlikely(slr->sl.locked))
 178                 rte_spinlock_recursive_unlock(slr);
 179         else
 180                 rte_xend();
 181 }
 182
 183 static inline int
 184 rte_spinlock_recursive_trylock_tm(rte_spinlock_recursive_t *slr)
 185 {
 186         if (likely(rte_try_tm(&slr->sl.locked)))
 187                 return 1;
 188
 189         return rte_spinlock_recursive_trylock(slr);
 190 }
 191
 192
 193 #ifdef __cplusplus
 194 }
 195 #endif
 196
 197 #endif /* _RTE_SPINLOCK_X86_64_H_ */