1 files changed, 169 insertions, 0 deletions
diff --git a/arch/arm/include/asm/proc-armv/system.h b/arch/arm/include/asm/proc-armv/system.h
new file mode 100644
index 0000000000..b4cfa68ca3
--- /dev/null
+++ b/arch/arm/include/asm/proc-armv/system.h
@@ -0,0 +1,169 @@
+/*
+ *  linux/include/asm-arm/proc-armv/system.h
+ *
+ *  Copyright (C) 1996 Russell King
+ *
+ * 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.
+ */
+#ifndef __ASM_PROC_SYSTEM_H
+#define __ASM_PROC_SYSTEM_H
+
+#include <linux/config.h>
+
+/*
+ * Save the current interrupt enable state & disable IRQs
+ */
+#define local_irq_save(x)					\
+	({							\
+		unsigned long temp;				\
+	__asm__ __volatile__(					\
+	"mrs	%0, cpsr		@ local_irq_save\n"	\
+"	orr	%1, %0, #128\n"					\
+"	msr	cpsr_c, %1"					\
+	: "=r" (x), "=r" (temp)					\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * Enable IRQs
+ */
+#define local_irq_enable()					\
+	({							\
+		unsigned long temp;				\
+	__asm__ __volatile__(					\
+	"mrs	%0, cpsr		@ local_irq_enable\n"	\
+"	bic	%0, %0, #128\n"					\
+"	msr	cpsr_c, %0"					\
+	: "=r" (temp)						\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * Disable IRQs
+ */
+#define local_irq_disable()					\
+	({							\
+		unsigned long temp;				\
+	__asm__ __volatile__(					\
+	"mrs	%0, cpsr		@ local_irq_disable\n"	\
+"	orr	%0, %0, #128\n"					\
+"	msr	cpsr_c, %0"					\
+	: "=r" (temp)						\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * Enable FIQs
+ */
+#define __stf()							\
+	({							\
+		unsigned long temp;				\
+	__asm__ __volatile__(					\
+	"mrs	%0, cpsr		@ stf\n"		\
+"	bic	%0, %0, #64\n"					\
+"	msr	cpsr_c, %0"					\
+	: "=r" (temp)						\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * Disable FIQs
+ */
+#define __clf()							\
+	({							\
+		unsigned long temp;				\
+	__asm__ __volatile__(					\
+	"mrs	%0, cpsr		@ clf\n"		\
+"	orr	%0, %0, #64\n"					\
+"	msr	cpsr_c, %0"					\
+	: "=r" (temp)						\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * Save the current interrupt enable state.
+ */
+#define local_save_flags(x)					\
+	({							\
+	__asm__ __volatile__(					\
+	"mrs	%0, cpsr		@ local_save_flags\n"	\
+	  : "=r" (x)						\
+	  :							\
+	  : "memory");						\
+	})
+
+/*
+ * restore saved IRQ & FIQ state
+ */
+#define local_irq_restore(x)					\
+	__asm__ __volatile__(					\
+	"msr	cpsr_c, %0		@ local_irq_restore\n"	\
+	:							\
+	: "r" (x)						\
+	: "memory")
+
+#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110)
+/*
+ * On the StrongARM, "swp" is terminally broken since it bypasses the
+ * cache totally.  This means that the cache becomes inconsistent, and,
+ * since we use normal loads/stores as well, this is really bad.
+ * Typically, this causes oopsen in filp_close, but could have other,
+ * more disasterous effects.  There are two work-arounds:
+ *  1. Disable interrupts and emulate the atomic swap
+ *  2. Clean the cache, perform atomic swap, flush the cache
+ *
+ * We choose (1) since its the "easiest" to achieve here and is not
+ * dependent on the processor type.
+ */
+#define swp_is_buggy
+#endif
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
+{
+	extern void __bad_xchg(volatile void *, int);
+	unsigned long ret;
+#ifdef swp_is_buggy
+	unsigned long flags;
+#endif
+
+	switch (size) {
+#ifdef swp_is_buggy
+		case 1:
+			local_irq_save(flags);
+			ret = *(volatile unsigned char *)ptr;
+			*(volatile unsigned char *)ptr = x;
+			local_irq_restore(flags);
+			break;
+
+		case 4:
+			local_irq_save(flags);
+			ret = *(volatile unsigned long *)ptr;
+			*(volatile unsigned long *)ptr = x;
+			local_irq_restore(flags);
+			break;
+#else
+		case 1:	__asm__ __volatile__ ("swpb %0, %1, [%2]"
+					: "=&r" (ret)
+					: "r" (x), "r" (ptr)
+					: "memory");
+			break;
+		case 4:	__asm__ __volatile__ ("swp %0, %1, [%2]"
+					: "=&r" (ret)
+					: "r" (x), "r" (ptr)
+					: "memory");
+			break;
+#endif
+		default: __bad_xchg(ptr, size), ret = 0;
+	}
+
+	return ret;
+}
+
+#endif