Initial import

1 files changed, 279 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
new file mode 100644
index 000000000..d8c25b7b1
--- /dev/null
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -0,0 +1,279 @@
+/*
+ * Based on arch/arm/include/asm/cmpxchg.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_CMPXCHG_H
+#define __ASM_CMPXCHG_H
+
+#include <linux/bug.h>
+#include <linux/mmdebug.h>
+
+#include <asm/barrier.h>
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
+{
+	unsigned long ret, tmp;
+
+	switch (size) {
+	case 1:
+		asm volatile("//	__xchg1\n"
+		"1:	ldxrb	%w0, %2\n"
+		"	stlxrb	%w1, %w3, %2\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)
+			: "r" (x)
+			: "memory");
+		break;
+	case 2:
+		asm volatile("//	__xchg2\n"
+		"1:	ldxrh	%w0, %2\n"
+		"	stlxrh	%w1, %w3, %2\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp), "+Q" (*(u16 *)ptr)
+			: "r" (x)
+			: "memory");
+		break;
+	case 4:
+		asm volatile("//	__xchg4\n"
+		"1:	ldxr	%w0, %2\n"
+		"	stlxr	%w1, %w3, %2\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp), "+Q" (*(u32 *)ptr)
+			: "r" (x)
+			: "memory");
+		break;
+	case 8:
+		asm volatile("//	__xchg8\n"
+		"1:	ldxr	%0, %2\n"
+		"	stlxr	%w1, %3, %2\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp), "+Q" (*(u64 *)ptr)
+			: "r" (x)
+			: "memory");
+		break;
+	default:
+		BUILD_BUG();
+	}
+
+	smp_mb();
+	return ret;
+}
+
+#define xchg(ptr,x) \
+({ \
+	__typeof__(*(ptr)) __ret; \
+	__ret = (__typeof__(*(ptr))) \
+		__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))); \
+	__ret; \
+})
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+				      unsigned long new, int size)
+{
+	unsigned long oldval = 0, res;
+
+	switch (size) {
+	case 1:
+		do {
+			asm volatile("// __cmpxchg1\n"
+			"	ldxrb	%w1, %2\n"
+			"	mov	%w0, #0\n"
+			"	cmp	%w1, %w3\n"
+			"	b.ne	1f\n"
+			"	stxrb	%w0, %w4, %2\n"
+			"1:\n"
+				: "=&r" (res), "=&r" (oldval), "+Q" (*(u8 *)ptr)
+				: "Ir" (old), "r" (new)
+				: "cc");
+		} while (res);
+		break;
+
+	case 2:
+		do {
+			asm volatile("// __cmpxchg2\n"
+			"	ldxrh	%w1, %2\n"
+			"	mov	%w0, #0\n"
+			"	cmp	%w1, %w3\n"
+			"	b.ne	1f\n"
+			"	stxrh	%w0, %w4, %2\n"
+			"1:\n"
+				: "=&r" (res), "=&r" (oldval), "+Q" (*(u16 *)ptr)
+				: "Ir" (old), "r" (new)
+				: "cc");
+		} while (res);
+		break;
+
+	case 4:
+		do {
+			asm volatile("// __cmpxchg4\n"
+			"	ldxr	%w1, %2\n"
+			"	mov	%w0, #0\n"
+			"	cmp	%w1, %w3\n"
+			"	b.ne	1f\n"
+			"	stxr	%w0, %w4, %2\n"
+			"1:\n"
+				: "=&r" (res), "=&r" (oldval), "+Q" (*(u32 *)ptr)
+				: "Ir" (old), "r" (new)
+				: "cc");
+		} while (res);
+		break;
+
+	case 8:
+		do {
+			asm volatile("// __cmpxchg8\n"
+			"	ldxr	%1, %2\n"
+			"	mov	%w0, #0\n"
+			"	cmp	%1, %3\n"
+			"	b.ne	1f\n"
+			"	stxr	%w0, %4, %2\n"
+			"1:\n"
+				: "=&r" (res), "=&r" (oldval), "+Q" (*(u64 *)ptr)
+				: "Ir" (old), "r" (new)
+				: "cc");
+		} while (res);
+		break;
+
+	default:
+		BUILD_BUG();
+	}
+
+	return oldval;
+}
+
+#define system_has_cmpxchg_double()     1
+
+static inline int __cmpxchg_double(volatile void *ptr1, volatile void *ptr2,
+		unsigned long old1, unsigned long old2,
+		unsigned long new1, unsigned long new2, int size)
+{
+	unsigned long loop, lost;
+
+	switch (size) {
+	case 8:
+		VM_BUG_ON((unsigned long *)ptr2 - (unsigned long *)ptr1 != 1);
+		do {
+			asm volatile("// __cmpxchg_double8\n"
+			"	ldxp	%0, %1, %2\n"
+			"	eor	%0, %0, %3\n"
+			"	eor	%1, %1, %4\n"
+			"	orr	%1, %0, %1\n"
+			"	mov	%w0, #0\n"
+			"	cbnz	%1, 1f\n"
+			"	stxp	%w0, %5, %6, %2\n"
+			"1:\n"
+				: "=&r"(loop), "=&r"(lost), "+Q" (*(u64 *)ptr1)
+				: "r" (old1), "r"(old2), "r"(new1), "r"(new2));
+		} while (loop);
+		break;
+	default:
+		BUILD_BUG();
+	}
+
+	return !lost;
+}
+
+static inline int __cmpxchg_double_mb(volatile void *ptr1, volatile void *ptr2,
+			unsigned long old1, unsigned long old2,
+			unsigned long new1, unsigned long new2, int size)
+{
+	int ret;
+
+	smp_mb();
+	ret = __cmpxchg_double(ptr1, ptr2, old1, old2, new1, new2, size);
+	smp_mb();
+
+	return ret;
+}
+
+static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
+					 unsigned long new, int size)
+{
+	unsigned long ret;
+
+	smp_mb();
+	ret = __cmpxchg(ptr, old, new, size);
+	smp_mb();
+
+	return ret;
+}
+
+#define cmpxchg(ptr, o, n) \
+({ \
+	__typeof__(*(ptr)) __ret; \
+	__ret = (__typeof__(*(ptr))) \
+		__cmpxchg_mb((ptr), (unsigned long)(o), (unsigned long)(n), \
+			     sizeof(*(ptr))); \
+	__ret; \
+})
+
+#define cmpxchg_local(ptr, o, n) \
+({ \
+	__typeof__(*(ptr)) __ret; \
+	__ret = (__typeof__(*(ptr))) \
+		__cmpxchg((ptr), (unsigned long)(o), \
+			  (unsigned long)(n), sizeof(*(ptr))); \
+	__ret; \
+})
+
+#define cmpxchg_double(ptr1, ptr2, o1, o2, n1, n2) \
+({\
+	int __ret;\
+	__ret = __cmpxchg_double_mb((ptr1), (ptr2), (unsigned long)(o1), \
+			(unsigned long)(o2), (unsigned long)(n1), \
+			(unsigned long)(n2), sizeof(*(ptr1)));\
+	__ret; \
+})
+
+#define cmpxchg_double_local(ptr1, ptr2, o1, o2, n1, n2) \
+({\
+	int __ret;\
+	__ret = __cmpxchg_double((ptr1), (ptr2), (unsigned long)(o1), \
+			(unsigned long)(o2), (unsigned long)(n1), \
+			(unsigned long)(n2), sizeof(*(ptr1)));\
+	__ret; \
+})
+
+#define _protect_cmpxchg_local(pcp, o, n)			\
+({								\
+	typeof(*raw_cpu_ptr(&(pcp))) __ret;			\
+	preempt_disable();					\
+	__ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n);	\
+	preempt_enable();					\
+	__ret;							\
+})
+
+#define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+
+#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2)		\
+({									\
+	int __ret;							\
+	preempt_disable();						\
+	__ret = cmpxchg_double_local(	raw_cpu_ptr(&(ptr1)),		\
+					raw_cpu_ptr(&(ptr2)),		\
+					o1, o2, n1, n2);		\
+	preempt_enable();						\
+	__ret;								\
+})
+
+#define cmpxchg64(ptr,o,n)		cmpxchg((ptr),(o),(n))
+#define cmpxchg64_local(ptr,o,n)	cmpxchg_local((ptr),(o),(n))
+
+#define cmpxchg64_relaxed(ptr,o,n)	cmpxchg_local((ptr),(o),(n))
+
+#endif	/* __ASM_CMPXCHG_H */