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		77b4cf5cb0
		
	
	
	
	
		
			
			Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Richard Henderson <rth@twiddle.net Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			117 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			117 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #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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| 	"	.section __ex_table,\"a\"\n"			\
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| 	"	.long	1b-.\n"					\
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| 	"	lda	$31,3b-1b(%1)\n"			\
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| 	"	.long	2b-.\n"					\
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| 	"	lda	$31,3b-2b(%1)\n"			\
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| 	"	.previous\n"					\
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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 futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
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| {
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| 	int op = (encoded_op >> 28) & 7;
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| 	int cmp = (encoded_op >> 24) & 15;
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| 	int oparg = (encoded_op << 8) >> 20;
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| 	int cmparg = (encoded_op << 20) >> 20;
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| 	int oldval = 0, ret;
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| 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
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| 		oparg = 1 << oparg;
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| 
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| 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
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| 		return -EFAULT;
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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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| 		switch (cmp) {
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| 		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
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| 		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
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| 		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
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| 		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
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| 		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
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| 		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
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| 		default: ret = -ENOSYS;
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| 		}
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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(int __user *uaddr, int oldval, int newval)
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| {
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| 	int prev, cmp;
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| 
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| 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
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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	%0,0(%2)\n"
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| 	"	cmpeq	%0,%3,%1\n"
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| 	"	beq	%1,3f\n"
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| 	"	mov	%4,%1\n"
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| 	"2:	stl_c	%1,0(%2)\n"
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| 	"	beq	%1,4f\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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| 	"	.section __ex_table,\"a\"\n"
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| 	"	.long	1b-.\n"
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| 	"	lda	$31,3b-1b(%0)\n"
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| 	"	.long	2b-.\n"
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| 	"	lda	$31,3b-2b(%0)\n"
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| 	"	.previous\n"
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| 	:	"=&r"(prev), "=&r"(cmp)
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| 	:	"r"(uaddr), "r"((long)oldval), "r"(newval)
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| 	:	"memory");
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| 
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| 	return prev;
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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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