arch/sparc/lib/atomic_64.S

   1 /* atomic.S: These things are too big to do inline.
   2  *
   3  * Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net)
   4  */
   5
   6 #include <linux/linkage.h>
   7 #include <asm/asi.h>
   8 #include <asm/backoff.h>
   9
  10         .text
  11
  12         /* Two versions of the atomic routines, one that
  13          * does not return a value and does not perform
  14          * memory barriers, and a second which returns
  15          * a value and does the barriers.
  16          */
  17
  18 #define ATOMIC_OP(op)                                                   \
  19 ENTRY(atomic_##op) /* %o0 = increment, %o1 = atomic_ptr */              \
  20         BACKOFF_SETUP(%o2);                                             \
  21 1:      lduw    [%o1], %g1;                                             \
  22         op      %g1, %o0, %g7;                                          \
  23         cas     [%o1], %g1, %g7;                                        \
  24         cmp     %g1, %g7;                                               \
  25         bne,pn  %icc, BACKOFF_LABEL(2f, 1b);                            \
  26          nop;                                                           \
  27         retl;                                                           \
  28          nop;                                                           \
  29 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  30 ENDPROC(atomic_##op);                                                   \
  31
  32 #define ATOMIC_OP_RETURN(op)                                            \
  33 ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */     \
  34         BACKOFF_SETUP(%o2);                                             \
  35 1:      lduw    [%o1], %g1;                                             \
  36         op      %g1, %o0, %g7;                                          \
  37         cas     [%o1], %g1, %g7;                                        \
  38         cmp     %g1, %g7;                                               \
  39         bne,pn  %icc, BACKOFF_LABEL(2f, 1b);                            \
  40          op     %g1, %o0, %g1;                                          \
  41         retl;                                                           \
  42          sra    %g1, 0, %o0;                                            \
  43 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  44 ENDPROC(atomic_##op##_return);
  45
  46 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
  47
  48 ATOMIC_OPS(add)
  49 ATOMIC_OPS(sub)
  50 ATOMIC_OP(and)
  51 ATOMIC_OP(or)
  52 ATOMIC_OP(xor)
  53
  54 #undef ATOMIC_OPS
  55 #undef ATOMIC_OP_RETURN
  56 #undef ATOMIC_OP
  57
  58 #define ATOMIC64_OP(op)                                                 \
  59 ENTRY(atomic64_##op) /* %o0 = increment, %o1 = atomic_ptr */            \
  60         BACKOFF_SETUP(%o2);                                             \
  61 1:      ldx     [%o1], %g1;                                             \
  62         op      %g1, %o0, %g7;                                          \
  63         casx    [%o1], %g1, %g7;                                        \
  64         cmp     %g1, %g7;                                               \
  65         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b);                            \
  66          nop;                                                           \
  67         retl;                                                           \
  68          nop;                                                           \
  69 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  70 ENDPROC(atomic64_##op);                                                 \
  71
  72 #define ATOMIC64_OP_RETURN(op)                                          \
  73 ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */   \
  74         BACKOFF_SETUP(%o2);                                             \
  75 1:      ldx     [%o1], %g1;                                             \
  76         op      %g1, %o0, %g7;                                          \
  77         casx    [%o1], %g1, %g7;                                        \
  78         cmp     %g1, %g7;                                               \
  79         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b);                            \
  80          nop;                                                           \
  81         retl;                                                           \
  82          op     %g1, %o0, %o0;                                          \
  83 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  84 ENDPROC(atomic64_##op##_return);
  85
  86 #define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
  87
  88 ATOMIC64_OPS(add)
  89 ATOMIC64_OPS(sub)
  90 ATOMIC64_OP(and)
  91 ATOMIC64_OP(or)
  92 ATOMIC64_OP(xor)
  93
  94 #undef ATOMIC64_OPS
  95 #undef ATOMIC64_OP_RETURN
  96 #undef ATOMIC64_OP
  97
  98 ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */
  99         BACKOFF_SETUP(%o2)
 100 1:      ldx     [%o0], %g1
 101         brlez,pn %g1, 3f
 102          sub    %g1, 1, %g7
 103         casx    [%o0], %g1, %g7
 104         cmp     %g1, %g7
 105         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b)
 106          nop
 107 3:      retl
 108          sub    %g1, 1, %o0
 109 2:      BACKOFF_SPIN(%o2, %o3, 1b)
 110 ENDPROC(atomic64_dec_if_positive)