arch/sparc64/lib/rwsem.S

   1 /* rwsem.S: RW semaphore assembler.
   2  *
   3  * Written by David S. Miller (davem@redhat.com), 2001.
   4  * Derived from asm-i386/rwsem.h
   5  */
   6
   7 #include <asm/rwsem-const.h>
   8
   9         .section        .sched.text
  10
  11         .globl          __down_read
  12 __down_read:
  13 1:      lduw            [%o0], %g1
  14         add             %g1, 1, %g7
  15         cas             [%o0], %g1, %g7
  16         cmp             %g1, %g7
  17         bne,pn          %icc, 1b
  18          add            %g7, 1, %g7
  19         cmp             %g7, 0
  20         bl,pn           %icc, 3f
  21          membar         #StoreLoad | #StoreStore
  22 2:
  23         retl
  24          nop
  25 3:
  26         save            %sp, -192, %sp
  27         call            rwsem_down_read_failed
  28          mov            %i0, %o0
  29         ret
  30          restore
  31         .size           __down_read, .-__down_read
  32
  33         .globl          __down_read_trylock
  34 __down_read_trylock:
  35 1:      lduw            [%o0], %g1
  36         add             %g1, 1, %g7
  37         cmp             %g7, 0
  38         bl,pn           %icc, 2f
  39          mov            0, %o1
  40         cas             [%o0], %g1, %g7
  41         cmp             %g1, %g7
  42         bne,pn          %icc, 1b
  43          mov            1, %o1
  44         membar          #StoreLoad | #StoreStore
  45 2:      retl
  46          mov            %o1, %o0
  47         .size           __down_read_trylock, .-__down_read_trylock
  48
  49         .globl          __down_write
  50 __down_write:
  51         sethi           %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1
  52         or              %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1
  53 1:
  54         lduw            [%o0], %g3
  55         add             %g3, %g1, %g7
  56         cas             [%o0], %g3, %g7
  57         cmp             %g3, %g7
  58         bne,pn          %icc, 1b
  59          cmp            %g7, 0
  60         bne,pn          %icc, 3f
  61          membar         #StoreLoad | #StoreStore
  62 2:      retl
  63          nop
  64 3:
  65         save            %sp, -192, %sp
  66         call            rwsem_down_write_failed
  67          mov            %i0, %o0
  68         ret
  69          restore
  70         .size           __down_write, .-__down_write
  71
  72         .globl          __down_write_trylock
  73 __down_write_trylock:
  74         sethi           %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1
  75         or              %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1
  76 1:
  77         lduw            [%o0], %g3
  78         cmp             %g3, 0
  79         bne,pn          %icc, 2f
  80          mov            0, %o1
  81         add             %g3, %g1, %g7
  82         cas             [%o0], %g3, %g7
  83         cmp             %g3, %g7
  84         bne,pn          %icc, 1b
  85          mov            1, %o1
  86         membar          #StoreLoad | #StoreStore
  87 2:      retl
  88          mov            %o1, %o0
  89         .size           __down_write_trylock, .-__down_write_trylock
  90
  91         .globl          __up_read
  92 __up_read:
  93 1:
  94         lduw            [%o0], %g1
  95         sub             %g1, 1, %g7
  96         cas             [%o0], %g1, %g7
  97         cmp             %g1, %g7
  98         bne,pn          %icc, 1b
  99          cmp            %g7, 0
 100         bl,pn           %icc, 3f
 101          membar         #StoreLoad | #StoreStore
 102 2:      retl
 103          nop
 104 3:      sethi           %hi(RWSEM_ACTIVE_MASK), %g1
 105         sub             %g7, 1, %g7
 106         or              %g1, %lo(RWSEM_ACTIVE_MASK), %g1
 107         andcc           %g7, %g1, %g0
 108         bne,pn          %icc, 2b
 109          nop
 110         save            %sp, -192, %sp
 111         call            rwsem_wake
 112          mov            %i0, %o0
 113         ret
 114          restore
 115         .size           __up_read, .-__up_read
 116
 117         .globl          __up_write
 118 __up_write:
 119         sethi           %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1
 120         or              %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1
 121 1:
 122         lduw            [%o0], %g3
 123         sub             %g3, %g1, %g7
 124         cas             [%o0], %g3, %g7
 125         cmp             %g3, %g7
 126         bne,pn          %icc, 1b
 127          sub            %g7, %g1, %g7
 128         cmp             %g7, 0
 129         bl,pn           %icc, 3f
 130          membar         #StoreLoad | #StoreStore
 131 2:
 132         retl
 133          nop
 134 3:
 135         save            %sp, -192, %sp
 136         call            rwsem_wake
 137          mov            %i0, %o0
 138         ret
 139          restore
 140         .size           __up_write, .-__up_write
 141
 142         .globl          __downgrade_write
 143 __downgrade_write:
 144         sethi           %hi(RWSEM_WAITING_BIAS), %g1
 145         or              %g1, %lo(RWSEM_WAITING_BIAS), %g1
 146 1:
 147         lduw            [%o0], %g3
 148         sub             %g3, %g1, %g7
 149         cas             [%o0], %g3, %g7
 150         cmp             %g3, %g7
 151         bne,pn          %icc, 1b
 152          sub            %g7, %g1, %g7
 153         cmp             %g7, 0
 154         bl,pn           %icc, 3f
 155          membar         #StoreLoad | #StoreStore
 156 2:
 157         retl
 158          nop
 159 3:
 160         save            %sp, -192, %sp
 161         call            rwsem_downgrade_wake
 162          mov            %i0, %o0
 163         ret
 164          restore
 165         .size           __downgrade_write, .-__downgrade_write