1 files changed, 125 insertions, 0 deletions
diff --git a/include/asm-x86/futex_64.h b/include/asm-x86/futex_64.h
new file mode 100644
index 000000000000..5cdfb08013c3
--- /dev/null
+++ b/include/asm-x86/futex_64.h
@@ -0,0 +1,125 @@
+#ifndef _ASM_FUTEX_H
+#define _ASM_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
+  __asm__ __volatile (						\
+"1:	" insn "\n"						\
+"2:	.section .fixup,\"ax\"\n\
+3:	mov	%3, %1\n\
+	jmp	2b\n\
+	.previous\n\
+	.section __ex_table,\"a\"\n\
+	.align	8\n\
+	.quad	1b,3b\n\
+	.previous"						\
+	: "=r" (oldval), "=r" (ret), "=m" (*uaddr)		\
+	: "i" (-EFAULT), "m" (*uaddr), "0" (oparg), "1" (0))
+
+#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
+  __asm__ __volatile (						\
+"1:	movl	%2, %0\n\
+	movl	%0, %3\n"					\
+	insn "\n"						\
+"2:	" LOCK_PREFIX "cmpxchgl %3, %2\n\
+	jnz	1b\n\
+3:	.section .fixup,\"ax\"\n\
+4:	mov	%5, %1\n\
+	jmp	3b\n\
+	.previous\n\
+	.section __ex_table,\"a\"\n\
+	.align	8\n\
+	.quad	1b,4b,2b,4b\n\
+	.previous"						\
+	: "=&a" (oldval), "=&r" (ret), "=m" (*uaddr),		\
+	  "=&r" (tem)						\
+	: "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))
+
+static inline int
+futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+{
+	int op = (encoded_op >> 28) & 7;
+	int cmp = (encoded_op >> 24) & 15;
+	int oparg = (encoded_op << 8) >> 20;
+	int cmparg = (encoded_op << 20) >> 20;
+	int oldval = 0, ret, tem;
+	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+		oparg = 1 << oparg;
+
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+		return -EFAULT;
+
+	pagefault_disable();
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
+				   uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	pagefault_enable();
+
+	if (!ret) {
+		switch (cmp) {
+		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
+		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
+		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
+		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
+		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
+		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
+		default: ret = -ENOSYS;
+		}
+	}
+	return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+{
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+		return -EFAULT;
+
+	__asm__ __volatile__(
+		"1:	" LOCK_PREFIX "cmpxchgl %3, %1		\n"
+
+		"2:	.section .fixup, \"ax\"			\n"
+		"3:	mov     %2, %0				\n"
+		"	jmp     2b				\n"
+		"	.previous				\n"
+
+		"	.section __ex_table, \"a\"		\n"
+		"	.align  8				\n"
+		"	.quad   1b,3b				\n"
+		"	.previous				\n"
+
+		: "=a" (oldval), "=m" (*uaddr)
+		: "i" (-EFAULT), "r" (newval), "0" (oldval)
+		: "memory"
+	);
+
+	return oldval;
+}
+
+#endif
+#endif