root/arch/sparc/lib/atomic_64.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* atomic.S: These things are too big to do inline.
   3  *
   4  * Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net)
   5  */
   6 
   7 #include <linux/linkage.h>
   8 #include <asm/asi.h>
   9 #include <asm/backoff.h>
  10 #include <asm/export.h>
  11 
  12         .text
  13 
  14         /* Three versions of the atomic routines, one that
  15          * does not return a value and does not perform
  16          * memory barriers, and a two which return
  17          * a value, the new and old value resp. and does the
  18          * barriers.
  19          */
  20 
  21 #define ATOMIC_OP(op)                                                   \
  22 ENTRY(atomic_##op) /* %o0 = increment, %o1 = atomic_ptr */              \
  23         BACKOFF_SETUP(%o2);                                             \
  24 1:      lduw    [%o1], %g1;                                             \
  25         op      %g1, %o0, %g7;                                          \
  26         cas     [%o1], %g1, %g7;                                        \
  27         cmp     %g1, %g7;                                               \
  28         bne,pn  %icc, BACKOFF_LABEL(2f, 1b);                            \
  29          nop;                                                           \
  30         retl;                                                           \
  31          nop;                                                           \
  32 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  33 ENDPROC(atomic_##op);                                                   \
  34 EXPORT_SYMBOL(atomic_##op);
  35 
  36 #define ATOMIC_OP_RETURN(op)                                            \
  37 ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */     \
  38         BACKOFF_SETUP(%o2);                                             \
  39 1:      lduw    [%o1], %g1;                                             \
  40         op      %g1, %o0, %g7;                                          \
  41         cas     [%o1], %g1, %g7;                                        \
  42         cmp     %g1, %g7;                                               \
  43         bne,pn  %icc, BACKOFF_LABEL(2f, 1b);                            \
  44          op     %g1, %o0, %g1;                                          \
  45         retl;                                                           \
  46          sra    %g1, 0, %o0;                                            \
  47 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  48 ENDPROC(atomic_##op##_return);                                          \
  49 EXPORT_SYMBOL(atomic_##op##_return);
  50 
  51 #define ATOMIC_FETCH_OP(op)                                             \
  52 ENTRY(atomic_fetch_##op) /* %o0 = increment, %o1 = atomic_ptr */        \
  53         BACKOFF_SETUP(%o2);                                             \
  54 1:      lduw    [%o1], %g1;                                             \
  55         op      %g1, %o0, %g7;                                          \
  56         cas     [%o1], %g1, %g7;                                        \
  57         cmp     %g1, %g7;                                               \
  58         bne,pn  %icc, BACKOFF_LABEL(2f, 1b);                            \
  59          nop;                                                           \
  60         retl;                                                           \
  61          sra    %g1, 0, %o0;                                            \
  62 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  63 ENDPROC(atomic_fetch_##op);                                             \
  64 EXPORT_SYMBOL(atomic_fetch_##op);
  65 
  66 ATOMIC_OP(add)
  67 ATOMIC_OP_RETURN(add)
  68 ATOMIC_FETCH_OP(add)
  69 
  70 ATOMIC_OP(sub)
  71 ATOMIC_OP_RETURN(sub)
  72 ATOMIC_FETCH_OP(sub)
  73 
  74 ATOMIC_OP(and)
  75 ATOMIC_FETCH_OP(and)
  76 
  77 ATOMIC_OP(or)
  78 ATOMIC_FETCH_OP(or)
  79 
  80 ATOMIC_OP(xor)
  81 ATOMIC_FETCH_OP(xor)
  82 
  83 #undef ATOMIC_FETCH_OP
  84 #undef ATOMIC_OP_RETURN
  85 #undef ATOMIC_OP
  86 
  87 #define ATOMIC64_OP(op)                                                 \
  88 ENTRY(atomic64_##op) /* %o0 = increment, %o1 = atomic_ptr */            \
  89         BACKOFF_SETUP(%o2);                                             \
  90 1:      ldx     [%o1], %g1;                                             \
  91         op      %g1, %o0, %g7;                                          \
  92         casx    [%o1], %g1, %g7;                                        \
  93         cmp     %g1, %g7;                                               \
  94         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b);                            \
  95          nop;                                                           \
  96         retl;                                                           \
  97          nop;                                                           \
  98 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
  99 ENDPROC(atomic64_##op);                                                 \
 100 EXPORT_SYMBOL(atomic64_##op);
 101 
 102 #define ATOMIC64_OP_RETURN(op)                                          \
 103 ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */   \
 104         BACKOFF_SETUP(%o2);                                             \
 105 1:      ldx     [%o1], %g1;                                             \
 106         op      %g1, %o0, %g7;                                          \
 107         casx    [%o1], %g1, %g7;                                        \
 108         cmp     %g1, %g7;                                               \
 109         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b);                            \
 110          nop;                                                           \
 111         retl;                                                           \
 112          op     %g1, %o0, %o0;                                          \
 113 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
 114 ENDPROC(atomic64_##op##_return);                                        \
 115 EXPORT_SYMBOL(atomic64_##op##_return);
 116 
 117 #define ATOMIC64_FETCH_OP(op)                                           \
 118 ENTRY(atomic64_fetch_##op) /* %o0 = increment, %o1 = atomic_ptr */      \
 119         BACKOFF_SETUP(%o2);                                             \
 120 1:      ldx     [%o1], %g1;                                             \
 121         op      %g1, %o0, %g7;                                          \
 122         casx    [%o1], %g1, %g7;                                        \
 123         cmp     %g1, %g7;                                               \
 124         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b);                            \
 125          nop;                                                           \
 126         retl;                                                           \
 127          mov    %g1, %o0;                                               \
 128 2:      BACKOFF_SPIN(%o2, %o3, 1b);                                     \
 129 ENDPROC(atomic64_fetch_##op);                                           \
 130 EXPORT_SYMBOL(atomic64_fetch_##op);
 131 
 132 ATOMIC64_OP(add)
 133 ATOMIC64_OP_RETURN(add)
 134 ATOMIC64_FETCH_OP(add)
 135 
 136 ATOMIC64_OP(sub)
 137 ATOMIC64_OP_RETURN(sub)
 138 ATOMIC64_FETCH_OP(sub)
 139 
 140 ATOMIC64_OP(and)
 141 ATOMIC64_FETCH_OP(and)
 142 
 143 ATOMIC64_OP(or)
 144 ATOMIC64_FETCH_OP(or)
 145 
 146 ATOMIC64_OP(xor)
 147 ATOMIC64_FETCH_OP(xor)
 148 
 149 #undef ATOMIC64_FETCH_OP
 150 #undef ATOMIC64_OP_RETURN
 151 #undef ATOMIC64_OP
 152 
 153 ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */
 154         BACKOFF_SETUP(%o2)
 155 1:      ldx     [%o0], %g1
 156         brlez,pn %g1, 3f
 157          sub    %g1, 1, %g7
 158         casx    [%o0], %g1, %g7
 159         cmp     %g1, %g7
 160         bne,pn  %xcc, BACKOFF_LABEL(2f, 1b)
 161          nop
 162 3:      retl
 163          sub    %g1, 1, %o0
 164 2:      BACKOFF_SPIN(%o2, %o3, 1b)
 165 ENDPROC(atomic64_dec_if_positive)
 166 EXPORT_SYMBOL(atomic64_dec_if_positive)