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Commit 69588298 authored by David Woodhouse's avatar David Woodhouse Committed by Paul Mackerras
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[POWERPC] Implement PowerPC futex_atomic_cmpxchg_inatomic(). 



The sys_[gs]et_robust_list() syscalls were wired up on PowerPC but
didn't work correctly because futex_atomic_cmpxchg_inatomic() wasn't
implemented.  Implement it, based on __cmpxchg_u32().

Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 20fb96e2

include/asm-powerpc/futex.h

+27 −1
Original line number Diff line number Diff line
@@ -84,7 +84,33 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) 
static inline int

futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)

{

	return -ENOSYS;

	int prev;



	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))

		return -EFAULT;



        __asm__ __volatile__ (

        LWSYNC_ON_SMP

"1:     lwarx   %0,0,%2         # futex_atomic_cmpxchg_inatomic\n\

        cmpw    0,%0,%3\n\

        bne-    3f\n"

        PPC405_ERR77(0,%2)

"2:     stwcx.  %4,0,%2\n\

        bne-    1b\n"

        ISYNC_ON_SMP

"3:	.section .fixup,\"ax\"\n\

4:	li	%0,%5\n\

	b	3b\n\

	.previous\n\

	.section __ex_table,\"a\"\n\

	.align 3\n\

	" PPC_LONG "1b,4b,2b,4b\n\

	.previous" \

        : "=&r" (prev), "+m" (*uaddr)

        : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)

        : "cc", "memory");



        return prev;

}



#endif /* __KERNEL__ */