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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/openrisc/include/asm/futex.h
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/* SPDX-License-Identifier: GPL-2.0 */

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#ifndef __ASM_OPENRISC_FUTEX_H

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#define __ASM_OPENRISC_FUTEX_H

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#ifdef __KERNEL__

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#include <linux/futex.h>

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#include <linux/uaccess.h>

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#include <asm/errno.h>

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#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \

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({								\

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	__asm__ __volatile__ (					\

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		"1:	l.lwa	%0, %2			\n"	\

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			insn				"\n"	\

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		"2:	l.swa	%2, %1			\n"	\

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		"	l.bnf	1b			\n"	\

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		"	 l.ori	%1, r0, 0		\n"	\

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		"3:					\n"	\

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

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		"4:	l.j	3b			\n"	\

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		"	 l.addi	%1, r0, %3		\n"	\

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		".previous				\n"	\

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

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		".word	1b,4b,2b,4b			\n"	\

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		".previous				\n"	\

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		: "=&r" (oldval), "=&r" (ret), "+m" (*uaddr)	\

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		: "i" (-EFAULT), "r" (oparg)			\

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		: "cc", "memory"				\

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		);						\

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})

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static inline int

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arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)

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{

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	int oldval = 0, ret;

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	if (!access_ok(uaddr, sizeof(u32)))

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		return -EFAULT;

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	switch (op) {

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	case FUTEX_OP_SET:

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		__futex_atomic_op("l.or %1,%4,%4", ret, oldval, uaddr, oparg);

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		break;

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	case FUTEX_OP_ADD:

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		__futex_atomic_op("l.add %1,%0,%4", ret, oldval, uaddr, oparg);

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		break;

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	case FUTEX_OP_OR:

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		__futex_atomic_op("l.or %1,%0,%4", ret, oldval, uaddr, oparg);

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		break;

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	case FUTEX_OP_ANDN:

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		__futex_atomic_op("l.and %1,%0,%4", ret, oldval, uaddr, ~oparg);

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		break;

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	case FUTEX_OP_XOR:

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		__futex_atomic_op("l.xor %1,%0,%4", ret, oldval, uaddr, oparg);

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		break;

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	default:

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		ret = -ENOSYS;

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	}

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	if (!ret)

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		*oval = oldval;

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	return ret;

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}

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static inline int

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futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,

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			      u32 oldval, u32 newval)

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{

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	int ret = 0;

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	u32 prev;

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	if (!access_ok(uaddr, sizeof(u32)))

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		return -EFAULT;

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	__asm__ __volatile__ (				\

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		"1:	l.lwa	%1, %2		\n"	\

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		"	l.sfeq	%1, %3		\n"	\

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		"	l.bnf	3f		\n"	\

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		"	 l.nop			\n"	\

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		"2:	l.swa	%2, %4		\n"	\

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		"	l.bnf	1b		\n"	\

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		"	 l.nop			\n"	\

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		"3:				\n"	\

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

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		"4:	l.j	3b		\n"	\

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		"	 l.addi	%0, r0, %5	\n"	\

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		".previous			\n"	\

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

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		".word	1b,4b,2b,4b		\n"	\

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		".previous			\n"	\

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

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

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		: "cc",	"memory"			\

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		);

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	*uval = prev;

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	return ret;

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}

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#endif /* __KERNEL__ */

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#endif /* __ASM_OPENRISC_FUTEX_H */

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