diff options
Diffstat (limited to 'libc/sysdeps')
| -rw-r--r-- | libc/sysdeps/linux/arc/bits/atomic.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/arc/bits/atomic.h b/libc/sysdeps/linux/arc/bits/atomic.h index 1fdc83f70..48f37879c 100644 --- a/libc/sysdeps/linux/arc/bits/atomic.h +++ b/libc/sysdeps/linux/arc/bits/atomic.h @@ -58,3 +58,27 @@ void __arc_link_error (void); #define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \ ({ __arc_link_error (); oldval; }) + +/* Store NEWVALUE in *MEM and return the old value. + Atomic EX is present in all configurations + */ + +#define __arch_exchange_32_acq(mem, newval) \ + ({ \ + __typeof__(*(mem)) val = newval; \ + \ + __asm__ __volatile__( \ + "ex %0, [%1]" \ + : "+r" (val) \ + : "r" (mem) \ + : "memory" ); \ + \ + val; \ + }) + +#define atomic_exchange_acq(mem, newval) \ + ({ \ + if (sizeof(*(mem)) != 4) \ + abort(); \ + __arch_exchange_32_acq(mem, newval); \ + }) |