ARM 5889/1: Add atomic64 routines for ARMv6k and above.

arch/arm/Kconfig

@@ -18,6 +18,7 @@ config ARM
 	select HAVE_KRETPROBES if (HAVE_KPROBES)
 	select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
 	select HAVE_GENERIC_DMA_COHERENT
+	select GENERIC_ATOMIC64 if (!CPU_32v6K)
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and

arch/arm/include/asm/atomic.h

@@ -247,6 +247,234 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 #define smp_mb__before_atomic_inc()	smp_mb()
 #define smp_mb__after_atomic_inc()	smp_mb()
 
+#ifndef CONFIG_GENERIC_ATOMIC64
+typedef struct {
+	u64 __aligned(8) counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(i) { (i) }
+
+static inline u64 atomic64_read(atomic64_t *v)
+{
+	u64 result;
+
+	__asm__ __volatile__("@ atomic64_read\n"
+"	ldrexd	%0, %H0, [%1]"
+	: "=&r" (result)
+	: "r" (&v->counter)
+	);
+
+	return result;
+}
+
+static inline void atomic64_set(atomic64_t *v, u64 i)
+{
+	u64 tmp;
+
+	__asm__ __volatile__("@ atomic64_set\n"
+"1:	ldrexd	%0, %H0, [%1]\n"
+"	strexd	%0, %2, %H2, [%1]\n"
+"	teq	%0, #0\n"
+"	bne	1b"
+	: "=&r" (tmp)
+	: "r" (&v->counter), "r" (i)
+	: "cc");
+}
+
+static inline void atomic64_add(u64 i, atomic64_t *v)
+{
+	u64 result;
+	unsigned long tmp;
+
+	__asm__ __volatile__("@ atomic64_add\n"
+"1:	ldrexd	%0, %H0, [%2]\n"
+"	adds	%0, %0, %3\n"
+"	adc	%H0, %H0, %H3\n"
+"	strexd	%1, %0, %H0, [%2]\n"
+"	teq	%1, #0\n"
+"	bne	1b"
+	: "=&r" (result), "=&r" (tmp)
+	: "r" (&v->counter), "r" (i)
+	: "cc");
+}
+
+static inline u64 atomic64_add_return(u64 i, atomic64_t *v)
+{
+	u64 result;
+	unsigned long tmp;
+
+	smp_mb();
+
+	__asm__ __volatile__("@ atomic64_add_return\n"
+"1:	ldrexd	%0, %H0, [%2]\n"
+"	adds	%0, %0, %3\n"
+"	adc	%H0, %H0, %H3\n"
+"	strexd	%1, %0, %H0, [%2]\n"
+"	teq	%1, #0\n"
+"	bne	1b"
+	: "=&r" (result), "=&r" (tmp)
+	: "r" (&v->counter), "r" (i)
+	: "cc");
+
+	smp_mb();
+
+	return result;
+}
+
+static inline void atomic64_sub(u64 i, atomic64_t *v)
+{
+	u64 result;
+	unsigned long tmp;
+
+	__asm__ __volatile__("@ atomic64_sub\n"
+"1:	ldrexd	%0, %H0, [%2]\n"
+"	subs	%0, %0, %3\n"
+"	sbc	%H0, %H0, %H3\n"
+"	strexd	%1, %0, %H0, [%2]\n"
+"	teq	%1, #0\n"
+"	bne	1b"
+	: "=&r" (result), "=&r" (tmp)
+	: "r" (&v->counter), "r" (i)
+	: "cc");
+}
+
+static inline u64 atomic64_sub_return(u64 i, atomic64_t *v)
+{
+	u64 result;
+	unsigned long tmp;
+
+	smp_mb();
+
+	__asm__ __volatile__("@ atomic64_sub_return\n"
+"1:	ldrexd	%0, %H0, [%2]\n"
+"	subs	%0, %0, %3\n"
+"	sbc	%H0, %H0, %H3\n"
+"	strexd	%1, %0, %H0, [%2]\n"
+"	teq	%1, #0\n"
+"	bne	1b"
+	: "=&r" (result), "=&r" (tmp)
+	: "r" (&v->counter), "r" (i)
+	: "cc");
+
+	smp_mb();
+
+	return result;
+}
+
+static inline u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old, u64 new)
+{
+	u64 oldval;
+	unsigned long res;
+
+	smp_mb();
+
+	do {
+		__asm__ __volatile__("@ atomic64_cmpxchg\n"
+		"ldrexd		%1, %H1, [%2]\n"
+		"mov		%0, #0\n"
+		"teq		%1, %3\n"
+		"teqeq		%H1, %H3\n"
+		"strexdeq	%0, %4, %H4, [%2]"
+		: "=&r" (res), "=&r" (oldval)
+		: "r" (&ptr->counter), "r" (old), "r" (new)
+		: "cc");
+	} while (res);
+
+	smp_mb();
+
+	return oldval;
+}
+
+static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new)
+{
+	u64 result;
+	unsigned long tmp;
+
+	smp_mb();
+
+	__asm__ __volatile__("@ atomic64_xchg\n"
+"1:	ldrexd	%0, %H0, [%2]\n"
+"	strexd	%1, %3, %H3, [%2]\n"
+"	teq	%1, #0\n"
+"	bne	1b"
+	: "=&r" (result), "=&r" (tmp)
+	: "r" (&ptr->counter), "r" (new)
+	: "cc");
+
+	smp_mb();
+
+	return result;
+}
+
+static inline u64 atomic64_dec_if_positive(atomic64_t *v)
+{
+	u64 result;
+	unsigned long tmp;
+
+	smp_mb();
+
+	__asm__ __volatile__("@ atomic64_dec_if_positive\n"
+"1:	ldrexd	%0, %H0, [%2]\n"
+"	subs	%0, %0, #1\n"
+"	sbc	%H0, %H0, #0\n"
+"	teq	%H0, #0\n"
+"	bmi	2f\n"
+"	strexd	%1, %0, %H0, [%2]\n"
+"	teq	%1, #0\n"
+"	bne	1b\n"
+"2:"
+	: "=&r" (result), "=&r" (tmp)
+	: "r" (&v->counter)
+	: "cc");
+
+	smp_mb();
+
+	return result;
+}
+
+static inline int atomic64_add_unless(atomic64_t *v, u64 a, u64 u)
+{
+	u64 val;
+	unsigned long tmp;
+	int ret = 1;
+
+	smp_mb();
+
+	__asm__ __volatile__("@ atomic64_add_unless\n"
+"1:	ldrexd	%0, %H0, [%3]\n"
+"	teq	%0, %4\n"
+"	teqeq	%H0, %H4\n"
+"	moveq	%1, #0\n"
+"	beq	2f\n"
+"	adds	%0, %0, %5\n"
+"	adc	%H0, %H0, %H5\n"
+"	strexd	%2, %0, %H0, [%3]\n"
+"	teq	%2, #0\n"
+"	bne	1b\n"
+"2:"
+	: "=&r" (val), "=&r" (ret), "=&r" (tmp)
+	: "r" (&v->counter), "r" (u), "r" (a)
+	: "cc");
+
+	if (ret)
+		smp_mb();
+
+	return ret;
+}
+
+#define atomic64_add_negative(a, v)	(atomic64_add_return((a), (v)) < 0)
+#define atomic64_inc(v)			atomic64_add(1LL, (v))
+#define atomic64_inc_return(v)		atomic64_add_return(1LL, (v))
+#define atomic64_inc_and_test(v)	(atomic64_inc_return(v) == 0)
+#define atomic64_sub_and_test(a, v)	(atomic64_sub_return((a), (v)) == 0)
+#define atomic64_dec(v)			atomic64_sub(1LL, (v))
+#define atomic64_dec_return(v)		atomic64_sub_return(1LL, (v))
+#define atomic64_dec_and_test(v)	(atomic64_dec_return((v)) == 0)
+#define atomic64_inc_not_zero(v)	atomic64_add_unless((v), 1LL, 0LL)
+
+#else /* !CONFIG_GENERIC_ATOMIC64 */
+#include <asm-generic/atomic64.h>
+#endif
 #include <asm-generic/atomic-long.h>
 #endif
 #endif