arm64: Miscellaneous header files

This patch introduces a few AArch64-specific header files together with
Kbuild entries for generic headers.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 173 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..e0e65b069d9e
--- /dev/null
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -0,0 +1,173 @@
+/*
+ * 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 <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:	ldaxrb	%w0, [%3]\n"
+		"	stlxrb	%w1, %w2, [%3]\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp)
+			: "r" (x), "r" (ptr)
+			: "memory", "cc");
+		break;
+	case 2:
+		asm volatile("//	__xchg2\n"
+		"1:	ldaxrh	%w0, [%3]\n"
+		"	stlxrh	%w1, %w2, [%3]\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp)
+			: "r" (x), "r" (ptr)
+			: "memory", "cc");
+		break;
+	case 4:
+		asm volatile("//	__xchg4\n"
+		"1:	ldaxr	%w0, [%3]\n"
+		"	stlxr	%w1, %w2, [%3]\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp)
+			: "r" (x), "r" (ptr)
+			: "memory", "cc");
+		break;
+	case 8:
+		asm volatile("//	__xchg8\n"
+		"1:	ldaxr	%0, [%3]\n"
+		"	stlxr	%w1, %2, [%3]\n"
+		"	cbnz	%w1, 1b\n"
+			: "=&r" (ret), "=&r" (tmp)
+			: "r" (x), "r" (ptr)
+			: "memory", "cc");
+		break;
+	default:
+		BUILD_BUG();
+	}
+
+	return ret;
+}
+
+#define xchg(ptr,x) \
+	((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+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)
+				: "r" (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)
+				: "r" (ptr), "Ir" (old), "r" (new)
+				: "memory", "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)
+				: "r" (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)
+				: "r" (ptr), "Ir" (old), "r" (new)
+				: "cc");
+		} while (res);
+		break;
+
+	default:
+		BUILD_BUG();
+	}
+
+	return oldval;
+}
+
+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)))__cmpxchg_mb((ptr),			\
+					  (unsigned long)(o),		\
+					  (unsigned long)(n),		\
+					  sizeof(*(ptr))))
+
+#define cmpxchg_local(ptr,o,n)						\
+	((__typeof__(*(ptr)))__cmpxchg((ptr),				\
+				       (unsigned long)(o),		\
+				       (unsigned long)(n),		\
+				       sizeof(*(ptr))))
+
+#endif	/* __ASM_CMPXCHG_H */