arch/sparc/include/asm/backoff.h

   1 #ifndef _SPARC64_BACKOFF_H
   2 #define _SPARC64_BACKOFF_H
   3
   4 #define BACKOFF_LIMIT   (4 * 1024)
   5
   6 #ifdef CONFIG_SMP
   7
   8 #define BACKOFF_SETUP(reg)      \
   9         mov     1, reg
  10
  11 #define BACKOFF_LABEL(spin_label, continue_label) \
  12         spin_label
  13
  14 #define BACKOFF_SPIN(reg, tmp, label)           \
  15         mov             reg, tmp;               \
  16 88:     rd              %ccr, %g0;              \
  17         rd              %ccr, %g0;              \
  18         rd              %ccr, %g0;              \
  19         .section        .pause_patch,"ax";      \
  20         .word           88b;                    \
  21         sllx            tmp, 7, tmp;            \
  22         wr              tmp, 0, %asr27;         \
  23         clr             tmp;                    \
  24         .previous;                              \
  25         brnz,pt         tmp, 88b;               \
  26          sub            tmp, 1, tmp;            \
  27         set             BACKOFF_LIMIT, tmp;     \
  28         cmp             reg, tmp;               \
  29         bg,pn           %xcc, label;            \
  30          nop;                                   \
  31         ba,pt           %xcc, label;            \
  32          sllx           reg, 1, reg;
  33
  34 #else
  35
  36 #define BACKOFF_SETUP(reg)
  37
  38 #define BACKOFF_LABEL(spin_label, continue_label) \
  39         continue_label
  40
  41 #define BACKOFF_SPIN(reg, tmp, label)
  42
  43 #endif
  44
  45 #endif /* _SPARC64_BACKOFF_H */