linux_dsm_epyc7002/arch/sh/include/asm/futex-llsc.h
Rich Felker 00b73d8d1b sh: add working futex atomic ops on userspace addresses for smp
The version of futex.h in asm-generic should really be adapted to do
the same thing so that this hideous code does not have to be
duplicated per-arch.

Signed-off-by: Rich Felker <dalias@libc.org>
2016-08-05 03:29:36 +00:00

42 lines
831 B
C

#ifndef __ASM_SH_FUTEX_LLSC_H
#define __ASM_SH_FUTEX_LLSC_H
static inline int atomic_futex_op_cmpxchg_inatomic(u32 *uval,
u32 __user *uaddr,
u32 oldval, u32 newval)
{
int err = 0;
__asm__ __volatile__(
"synco\n"
"1:\n\t"
"movli.l @%2, r0\n\t"
"mov r0, %1\n\t"
"cmp/eq %1, %4\n\t"
"bf 2f\n\t"
"mov %5, r0\n\t"
"movco.l r0, @%2\n\t"
"bf 1b\n"
"2:\n\t"
"synco\n\t"
#ifdef CONFIG_MMU
".section .fixup,\"ax\"\n"
"3:\n\t"
"mov.l 4f, %0\n\t"
"jmp @%0\n\t"
" mov %3, %0\n\t"
".balign 4\n"
"4: .long 2b\n\t"
".previous\n"
".section __ex_table,\"a\"\n\t"
".long 1b, 3b\n\t"
".previous"
#endif
:"+r" (err), "=&r" (*uval)
:"r" (uaddr), "i" (-EFAULT), "r" (oldval), "r" (newval)
:"t", "memory", "r0");
if (err) return err;
return 0;
}
#endif /* __ASM_SH_FUTEX_LLSC_H */