95 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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|  */
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| #ifndef _ASM_FUTEX_H
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| #define _ASM_FUTEX_H
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| 
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| #include <linux/futex.h>
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| #include <linux/uaccess.h>
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| #include <asm/asm-extable.h>
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| #include <asm/barrier.h>
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| #include <asm/errno.h>
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| 
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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:	ll.w	%1, %4 # __futex_atomic_op\n"		\
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| 	"	" insn	"				\n"	\
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| 	"2:	sc.w	$t0, %2				\n"	\
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| 	"	beqz	$t0, 1b				\n"	\
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| 	"3:						\n"	\
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| 	_ASM_EXTABLE_UACCESS_ERR(1b, 3b, %0)			\
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| 	_ASM_EXTABLE_UACCESS_ERR(2b, 3b, %0)			\
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| 	: "=r" (ret), "=&r" (oldval),				\
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| 	  "=ZC" (*uaddr)					\
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| 	: "0" (0), "ZC" (*uaddr), "Jr" (oparg)			\
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| 	: "memory", "t0");					\
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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 = 0;
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| 
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| 	pagefault_disable();
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| 
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| 	switch (op) {
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| 	case FUTEX_OP_SET:
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| 		__futex_atomic_op("move $t0, %z5", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_ADD:
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| 		__futex_atomic_op("add.w $t0, %1, %z5", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_OR:
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| 		__futex_atomic_op("or	$t0, %1, %z5", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_ANDN:
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| 		__futex_atomic_op("and	$t0, %1, %z5", ret, oldval, uaddr, ~oparg);
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| 		break;
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| 	case FUTEX_OP_XOR:
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| 		__futex_atomic_op("xor	$t0, %1, %z5", 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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| 
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| 	pagefault_enable();
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| 
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| 	if (!ret)
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| 		*oval = oldval;
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| 
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| 	return ret;
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| }
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| 
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| static inline int
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| futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval)
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| {
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| 	int ret = 0;
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| 	u32 val = 0;
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| 
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| 	if (!access_ok(uaddr, sizeof(u32)))
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| 		return -EFAULT;
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| 
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| 	__asm__ __volatile__(
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| 	"# futex_atomic_cmpxchg_inatomic			\n"
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| 	"1:	ll.w	%1, %3					\n"
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| 	"	bne	%1, %z4, 3f				\n"
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| 	"	move	$t0, %z5				\n"
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| 	"2:	sc.w	$t0, %2					\n"
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| 	"	beqz	$t0, 1b					\n"
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| 	"3:							\n"
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| 	__WEAK_LLSC_MB
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| 	_ASM_EXTABLE_UACCESS_ERR(1b, 3b, %0)
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| 	_ASM_EXTABLE_UACCESS_ERR(2b, 3b, %0)
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| 	: "+r" (ret), "=&r" (val), "=ZC" (*uaddr)
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| 	: "ZC" (*uaddr), "Jr" (oldval), "Jr" (newval)
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| 	: "memory", "t0");
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| 
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| 	*uval = val;
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| 
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| 	return ret;
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| }
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| 
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| #endif /* _ASM_FUTEX_H */
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