arch/x86_64/lib/rwlock.S

   1 /* Slow paths of read/write spinlocks. */
   2
   3 #include <linux/linkage.h>
   4 #include <asm/rwlock.h>
   5 #include <asm/alternative-asm.i>
   6 #include <asm/dwarf2.h>
   7
   8 /* rdi: pointer to rwlock_t */
   9 ENTRY(__write_lock_failed)
  10         CFI_STARTPROC
  11         LOCK_PREFIX
  12         addl $RW_LOCK_BIAS,(%rdi)
  13 1:      rep
  14         nop
  15         cmpl $RW_LOCK_BIAS,(%rdi)
  16         jne 1b
  17         LOCK_PREFIX
  18         subl $RW_LOCK_BIAS,(%rdi)
  19         jnz  __write_lock_failed
  20         ret
  21         CFI_ENDPROC
  22 END(__write_lock_failed)
  23
  24 /* rdi: pointer to rwlock_t */
  25 ENTRY(__read_lock_failed)
  26         CFI_STARTPROC
  27         LOCK_PREFIX
  28         incl (%rdi)
  29 1:      rep
  30         nop
  31         cmpl $1,(%rdi)
  32         js 1b
  33         LOCK_PREFIX
  34         decl (%rdi)
  35         js __read_lock_failed
  36         ret
  37         CFI_ENDPROC
  38 END(__read_lock_failed)