ARM: Add atomic.h from u-boot v2016.03

atomic-long.h:
* Replace __UBOOT__ with __BAREBOX__

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 335 insertions, 0 deletions

diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
new file mode 100644
index 0000000000..9b79506b59
--- /dev/null
+++ b/arch/arm/include/asm/atomic.h
@@ -0,0 +1,111 @@
+/*
+ *  linux/include/asm-arm/atomic.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.
+ *
+ *  Changelog:
+ *   27-06-1996	RMK	Created
+ *   13-04-1997	RMK	Made functions atomic!
+ *   07-12-1997	RMK	Upgraded for v2.1.
+ *   26-08-1998	PJB	Added #ifdef __KERNEL__
+ */
+#ifndef __ASM_ARM_ATOMIC_H
+#define __ASM_ARM_ATOMIC_H
+
+#ifdef CONFIG_SMP
+#error SMP not supported
+#endif
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+#ifdef __KERNEL__
+#include <asm/proc-armv/system.h>
+
+#define atomic_read(v)	((v)->counter)
+#define atomic_set(v,i)	(((v)->counter) = (i))
+
+static inline void atomic_add(int i, volatile atomic_t *v)
+{
+	unsigned long flags = 0;
+
+	local_irq_save(flags);
+	v->counter += i;
+	local_irq_restore(flags);
+}
+
+static inline void atomic_sub(int i, volatile atomic_t *v)
+{
+	unsigned long flags = 0;
+
+	local_irq_save(flags);
+	v->counter -= i;
+	local_irq_restore(flags);
+}
+
+static inline void atomic_inc(volatile atomic_t *v)
+{
+	unsigned long flags = 0;
+
+	local_irq_save(flags);
+	v->counter += 1;
+	local_irq_restore(flags);
+}
+
+static inline void atomic_dec(volatile atomic_t *v)
+{
+	unsigned long flags = 0;
+
+	local_irq_save(flags);
+	v->counter -= 1;
+	local_irq_restore(flags);
+}
+
+static inline int atomic_dec_and_test(volatile atomic_t *v)
+{
+	unsigned long flags = 0;
+	int val;
+
+	local_irq_save(flags);
+	val = v->counter;
+	v->counter = val -= 1;
+	local_irq_restore(flags);
+
+	return val == 0;
+}
+
+static inline int atomic_add_negative(int i, volatile atomic_t *v)
+{
+	unsigned long flags = 0;
+	int val;
+
+	local_irq_save(flags);
+	val = v->counter;
+	v->counter = val += i;
+	local_irq_restore(flags);
+
+	return val < 0;
+}
+
+static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+{
+	unsigned long flags = 0;
+
+	local_irq_save(flags);
+	*addr &= ~mask;
+	local_irq_restore(flags);
+}
+
+/* Atomic operations are already serializing on ARM */
+#define smp_mb__before_atomic_dec()	barrier()
+#define smp_mb__after_atomic_dec()	barrier()
+#define smp_mb__before_atomic_inc()	barrier()
+#define smp_mb__after_atomic_inc()	barrier()
+
+#endif
+#endif
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..c61374e9f2
--- /dev/null
+++ b/arch/arm/include/asm/proc-armv/system.h
@@ -0,0 +1,224 @@
+/*
+ *  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
+
+/*
+ * Save the current interrupt enable state & disable IRQs
+ */
+#ifdef CONFIG_ARM64
+
+/*
+ * Save the current interrupt enable state
+ * and disable IRQs/FIQs
+ */
+#define local_irq_save(flags)					\
+	({							\
+	asm volatile(						\
+	"mrs	%0, daif\n"					\
+	"msr	daifset, #3"					\
+	: "=r" (flags)						\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * restore saved IRQ & FIQ state
+ */
+#define local_irq_restore(flags)				\
+	({							\
+	asm volatile(						\
+	"msr	daif, %0"					\
+	:							\
+	: "r" (flags)						\
+	: "memory");						\
+	})
+
+/*
+ * Enable IRQs/FIQs
+ */
+#define local_irq_enable()					\
+	({							\
+	asm volatile(						\
+	"msr	daifclr, #3"					\
+	:							\
+	:							\
+	: "memory");						\
+	})
+
+/*
+ * Disable IRQs/FIQs
+ */
+#define local_irq_disable()					\
+	({							\
+	asm volatile(						\
+	"msr	daifset, #3"					\
+	:							\
+	:							\
+	: "memory");						\
+	})
+
+#else	/* CONFIG_ARM64 */
+
+#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")
+
+#endif	/* CONFIG_ARM64 */
+
+#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110) || \
+	defined(CONFIG_ARM64)
+/*
+ * 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