 e5bb8ad862
			
		
	
	
	e5bb8ad862
	
	
	
		
			
			All 486+ CPUs support BSWAP, so remove the fallback 386 support code. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1354132230-21854-5-git-send-email-hpa@linux.intel.com
		
			
				
	
	
		
			136 lines
		
	
	
	
		
			3.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
	
		
			3.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _ASM_X86_FUTEX_H
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| #define _ASM_X86_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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| 
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| #include <asm/asm.h>
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| #include <asm/errno.h>
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| #include <asm/processor.h>
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| #include <asm/smap.h>
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| 
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| #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg)	\
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| 	asm volatile("\t" ASM_STAC "\n"				\
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| 		     "1:\t" insn "\n"				\
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| 		     "2:\t" ASM_CLAC "\n"			\
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| 		     "\t.section .fixup,\"ax\"\n"		\
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| 		     "3:\tmov\t%3, %1\n"			\
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| 		     "\tjmp\t2b\n"				\
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| 		     "\t.previous\n"				\
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| 		     _ASM_EXTABLE(1b, 3b)			\
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| 		     : "=r" (oldval), "=r" (ret), "+m" (*uaddr)	\
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| 		     : "i" (-EFAULT), "0" (oparg), "1" (0))
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| 
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| #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg)	\
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| 	asm volatile("\t" ASM_STAC "\n"				\
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| 		     "1:\tmovl	%2, %0\n"			\
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| 		     "\tmovl\t%0, %3\n"				\
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| 		     "\t" insn "\n"				\
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| 		     "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"	\
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| 		     "\tjnz\t1b\n"				\
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| 		     "3:\t" ASM_CLAC "\n"			\
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| 		     "\t.section .fixup,\"ax\"\n"		\
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| 		     "4:\tmov\t%5, %1\n"			\
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| 		     "\tjmp\t3b\n"				\
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| 		     "\t.previous\n"				\
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| 		     _ASM_EXTABLE(1b, 4b)			\
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| 		     _ASM_EXTABLE(2b, 4b)			\
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| 		     : "=&a" (oldval), "=&r" (ret),		\
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| 		       "+m" (*uaddr), "=&r" (tem)		\
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| 		     : "r" (oparg), "i" (-EFAULT), "1" (0))
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| 
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| static inline int futex_atomic_op_inuser(int encoded_op, u32 __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, tem;
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| 
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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(u32)))
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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_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_ADD:
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| 		__futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
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| 				   uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_OR:
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| 		__futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
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| 		break;
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| 	case FUTEX_OP_ANDN:
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| 		__futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
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| 		break;
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| 	case FUTEX_OP_XOR:
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| 		__futex_atomic_op2("xorl %4, %3", 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:
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| 			ret = (oldval == cmparg);
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| 			break;
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| 		case FUTEX_OP_CMP_NE:
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| 			ret = (oldval != cmparg);
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| 			break;
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| 		case FUTEX_OP_CMP_LT:
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| 			ret = (oldval < cmparg);
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| 			break;
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| 		case FUTEX_OP_CMP_GE:
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| 			ret = (oldval >= cmparg);
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| 			break;
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| 		case FUTEX_OP_CMP_LE:
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| 			ret = (oldval <= cmparg);
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| 			break;
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| 		case FUTEX_OP_CMP_GT:
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| 			ret = (oldval > cmparg);
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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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| 	return ret;
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| }
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| 
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| static inline int 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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| 
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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("\t" ASM_STAC "\n"
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| 		     "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
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| 		     "2:\t" ASM_CLAC "\n"
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| 		     "\t.section .fixup, \"ax\"\n"
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| 		     "3:\tmov     %3, %0\n"
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| 		     "\tjmp     2b\n"
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| 		     "\t.previous\n"
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| 		     _ASM_EXTABLE(1b, 3b)
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| 		     : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
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| 		     : "i" (-EFAULT), "r" (newval), "1" (oldval)
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| 		     : "memory"
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| 	);
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| 
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| 	*uval = oldval;
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| 	return ret;
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| }
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| 
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| #endif
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| #endif /* _ASM_X86_FUTEX_H */
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