97 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _ASM_ALPHA_FUTEX_H
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| #define _ASM_ALPHA_FUTEX_H
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| 
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| #ifdef __KERNEL__
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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/errno.h>
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| #include <asm/barrier.h>
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| 
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| #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)	\
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| 	__asm__ __volatile__(					\
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| 		__ASM_SMP_MB					\
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| 	"1:	ldl_l	%0,0(%2)\n"				\
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| 		insn						\
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| 	"2:	stl_c	%1,0(%2)\n"				\
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| 	"	beq	%1,4f\n"				\
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| 	"	mov	$31,%1\n"				\
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| 	"3:	.subsection 2\n"				\
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| 	"4:	br	1b\n"					\
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| 	"	.previous\n"					\
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| 	EXC(1b,3b,$31,%1)					\
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| 	EXC(2b,3b,$31,%1)					\
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| 	:	"=&r" (oldval), "=&r"(ret)			\
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| 	:	"r" (uaddr), "r"(oparg)				\
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| 	:	"memory")
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| 
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| static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
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| 		u32 __user *uaddr)
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| {
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| 	int oldval = 0, ret;
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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("mov %3,%1\n", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_ADD:
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| 		__futex_atomic_op("addl %0,%3,%1\n", 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 %0,%3,%1\n", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_ANDN:
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| 		__futex_atomic_op("andnot %0,%3,%1\n", 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 %0,%3,%1\n", 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,
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| 			      u32 oldval, u32 newval)
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| {
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| 	int ret = 0, cmp;
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| 	u32 prev;
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| 
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| 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
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| 		return -EFAULT;
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| 
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| 	__asm__ __volatile__ (
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| 		__ASM_SMP_MB
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| 	"1:	ldl_l	%1,0(%3)\n"
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| 	"	cmpeq	%1,%4,%2\n"
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| 	"	beq	%2,3f\n"
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| 	"	mov	%5,%2\n"
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| 	"2:	stl_c	%2,0(%3)\n"
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| 	"	beq	%2,4f\n"
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| 	"3:	.subsection 2\n"
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| 	"4:	br	1b\n"
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| 	"	.previous\n"
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| 	EXC(1b,3b,$31,%0)
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| 	EXC(2b,3b,$31,%0)
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| 	:	"+r"(ret), "=&r"(prev), "=&r"(cmp)
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| 	:	"r"(uaddr), "r"((long)(int)oldval), "r"(newval)
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| 	:	"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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| 
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| #endif /* __KERNEL__ */
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| #endif /* _ASM_ALPHA_FUTEX_H */
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