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
  47 #define RTE_RTM_MAX_RETRIES (10)
  48 #define RTE_XABORT_LOCK_BUSY (0xff)
  49
  50 #ifndef RTE_FORCE_INTRINSICS
  51 static inline void
  52 rte_spinlock_lock(rte_spinlock_t *sl)
  53 {
  54         int lock_val = 1;
  55         asm volatile (
  56                         "1:\n"
  57                         "xchg %[locked], %[lv]\n"
  58                         "test %[lv], %[lv]\n"
  59                         "jz 3f\n"
  60                         "2:\n"
  61                         "pause\n"
  62                         "cmpl $0, %[locked]\n"
  63                         "jnz 2b\n"
  64                         "jmp 1b\n"
  65                         "3:\n"
  66                         : [locked] "=m" (sl->locked), [lv] "=q" (lock_val)
  67                         : "[lv]" (lock_val)
  68                         : "memory");
  69 }
  70
  71 static inline void
  72 rte_spinlock_unlock (rte_spinlock_t *sl)
  73 {
  74         int unlock_val = 0;
  75         asm volatile (
  76                         "xchg %[locked], %[ulv]\n"
  77                         : [locked] "=m" (sl->locked), [ulv] "=q" (unlock_val)
  78                         : "[ulv]" (unlock_val)
  79                         : "memory");
  80 }
  81
  82 static inline int
  83 rte_spinlock_trylock (rte_spinlock_t *sl)
  84 {
  85         int lockval = 1;
  86
  87         asm volatile (
  88                         "xchg %[locked], %[lockval]"
  89                         : [locked] "=m" (sl->locked), [lockval] "=q" (lockval)
  90                         : "[lockval]" (lockval)
  91                         : "memory");
  92
  93         return lockval == 0;
  94 }
  95 #endif
  96
  97 extern uint8_t rte_rtm_supported;
  98
  99 static inline int rte_tm_supported(void)
 100 {
 101         return rte_rtm_supported;
 102 }
 103
 104 static inline int
 105 rte_try_tm(volatile int *lock)
 106 {
 107         int retries;
 108
 109         if (!rte_rtm_supported)
 110                 return 0;
 111
 112         retries = RTE_RTM_MAX_RETRIES;
 113
 114         while (likely(retries--)) {
 115
 116                 unsigned int status = rte_xbegin();
 117
 118                 if (likely(RTE_XBEGIN_STARTED == status)) {
 119                         if (unlikely(*lock))
 120                                 rte_xabort(RTE_XABORT_LOCK_BUSY);
 121                         else
 122                                 return 1;
 123                 }
 124                 while (*lock)
 125                         rte_pause();
 126
 127                 if ((status & RTE_XABORT_EXPLICIT) &&
 128                         (RTE_XABORT_CODE(status) == RTE_XABORT_LOCK_BUSY))
 129                         continue;
 130
 131                 if ((status & RTE_XABORT_RETRY) == 0) /* do not retry */
 132                         break;
 133         }
 134         return 0;
 135 }
 136
 137 static inline void
 138 rte_spinlock_lock_tm(rte_spinlock_t *sl)
 139 {
 140         if (likely(rte_try_tm(&sl->locked)))
 141                 return;
 142
 143         rte_spinlock_lock(sl); /* fall-back */
 144 }
 145
 146 static inline int
 147 rte_spinlock_trylock_tm(rte_spinlock_t *sl)
 148 {
 149         if (likely(rte_try_tm(&sl->locked)))
 150                 return 1;
 151
 152         return rte_spinlock_trylock(sl);
 153 }
 154
 155 static inline void
 156 rte_spinlock_unlock_tm(rte_spinlock_t *sl)
 157 {
 158         if (unlikely(sl->locked))
 159                 rte_spinlock_unlock(sl);
 160         else
 161                 rte_xend();
 162 }
 163
 164 static inline void
 165 rte_spinlock_recursive_lock_tm(rte_spinlock_recursive_t *slr)
 166 {
 167         if (likely(rte_try_tm(&slr->sl.locked)))
 168                 return;
 169
 170         rte_spinlock_recursive_lock(slr); /* fall-back */
 171 }
 172
 173 static inline void
 174 rte_spinlock_recursive_unlock_tm(rte_spinlock_recursive_t *slr)
 175 {
 176         if (unlikely(slr->sl.locked))
 177                 rte_spinlock_recursive_unlock(slr);
 178         else
 179                 rte_xend();
 180 }
 181
 182 static inline int
 183 rte_spinlock_recursive_trylock_tm(rte_spinlock_recursive_t *slr)
 184 {
 185         if (likely(rte_try_tm(&slr->sl.locked)))
 186                 return 1;
 187
 188         return rte_spinlock_recursive_trylock(slr);
 189 }
 190
 191
 192 #ifdef __cplusplus
 193 }
 194 #endif
 195
 196 #endif /* _RTE_SPINLOCK_X86_64_H_ */