From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 arch/alpha/include/asm/futex.h | 119 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 arch/alpha/include/asm/futex.h

(limited to 'arch/alpha/include/asm/futex.h')

diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h
new file mode 100644
index 00000000..f9397943
--- /dev/null
+++ b/arch/alpha/include/asm/futex.h
@@ -0,0 +1,119 @@
+#ifndef _ASM_ALPHA_FUTEX_H
+#define _ASM_ALPHA_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+#include <asm/barrier.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)	\
+	__asm__ __volatile__(					\
+		__ASM_SMP_MB					\
+	"1:	ldl_l	%0,0(%2)\n"				\
+		insn						\
+	"2:	stl_c	%1,0(%2)\n"				\
+	"	beq	%1,4f\n"				\
+	"	mov	$31,%1\n"				\
+	"3:	.subsection 2\n"				\
+	"4:	br	1b\n"					\
+	"	.previous\n"					\
+	"	.section __ex_table,\"a\"\n"			\
+	"	.long	1b-.\n"					\
+	"	lda	$31,3b-1b(%1)\n"			\
+	"	.long	2b-.\n"					\
+	"	lda	$31,3b-2b(%1)\n"			\
+	"	.previous\n"					\
+	:	"=&r" (oldval), "=&r"(ret)			\
+	:	"r" (uaddr), "r"(oparg)				\
+	:	"memory")
+
+static inline int futex_atomic_op_inuser (int encoded_op, u32 __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;
+	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+		oparg = 1 << oparg;
+
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+		return -EFAULT;
+
+	pagefault_disable();
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op("xor %0,%3,%1\n", 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(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
+{
+	int ret = 0, cmp;
+	u32 prev;
+
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+		return -EFAULT;
+
+	__asm__ __volatile__ (
+		__ASM_SMP_MB
+	"1:	ldl_l	%1,0(%3)\n"
+	"	cmpeq	%1,%4,%2\n"
+	"	beq	%2,3f\n"
+	"	mov	%5,%2\n"
+	"2:	stl_c	%2,0(%3)\n"
+	"	beq	%2,4f\n"
+	"3:	.subsection 2\n"
+	"4:	br	1b\n"
+	"	.previous\n"
+	"	.section __ex_table,\"a\"\n"
+	"	.long	1b-.\n"
+	"	lda	$31,3b-1b(%0)\n"
+	"	.long	2b-.\n"
+	"	lda	$31,3b-2b(%0)\n"
+	"	.previous\n"
+	:	"+r"(ret), "=&r"(prev), "=&r"(cmp)
+	:	"r"(uaddr), "r"((long)(int)oldval), "r"(newval)
+	:	"memory");
+
+	*uval = prev;
+	return ret;
+}
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_ALPHA_FUTEX_H */
-- 
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