implement the atomic_foo things on arm.

testing and ok jsg@

1 files changed, 181 insertions, 3 deletions

diff --git a/sys/arch/arm/include/atomic.h b/sys/arch/arm/include/atomic.h
index 83f3a42c6d8..ba80cb085eb 100644
--- a/sys/arch/arm/include/atomic.h
+++ b/sys/arch/arm/include/atomic.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: atomic.h,v 1.9 2014/03/29 18:09:28 guenther Exp $	*/
+/*	$OpenBSD: atomic.h,v 1.10 2014/11/14 09:56:06 dlg Exp $	*/
 
 /* Public Domain */
 
@@ -7,13 +7,191 @@
 
 #if defined(_KERNEL)
 
+#include <arm/cpufunc.h>
+
 /*
  * on pre-v6 arm processors, it is necessary to disable interrupts if
  * in the kernel and atomic updates are necessary without full mutexes
+*
+ * eventually it would be interesting to have these functions
+ * support the V6/V7+ atomic instructions ldrex/strex if available
+ * on the CPU.
  */
 
-void atomic_setbits_int(volatile unsigned int *, unsigned int);
-void atomic_clearbits_int(volatile unsigned int *, unsigned int);
+static inline unsigned int
+_atomic_cas_uint(volatile unsigned int *uip, unsigned int o, unsigned int n)
+{
+	unsigned int cpsr;
+	unsigned int rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip;
+	if (rv == o)
+		*uip = n;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_cas_uint(_p, _o, _n) _atomic_cas_uint((_p), (_o), (_n))
+
+static inline unsigned int
+_atomic_cas_ulong(volatile unsigned long *uip, unsigned long o, unsigned long n)
+{
+	unsigned int cpsr;
+	unsigned long rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip;
+	if (rv == o)
+		*uip = n;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_cas_ulong(_p, _o, _n) _atomic_cas_ulong((_p), (_o), (_n))
+
+static inline void *
+_atomic_cas_ptr(volatile void *uip, void *o, void *n)
+{
+	unsigned int cpsr;
+	void * volatile *uipp = (void * volatile *)uip;
+	void *rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uipp;
+	if (rv == o)
+		*uipp = n;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_cas_ptr(_p, _o, _n) _atomic_cas_ptr((_p), (_o), (_n))
+
+static inline unsigned int
+_atomic_swap_uint(volatile unsigned int *uip, unsigned int n)
+{
+	unsigned int cpsr;
+	unsigned int rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip;
+	*uip = n;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_swap_uint(_p, _n) _atomic_swap_uint((_p), (_n))
+
+static inline unsigned long
+_atomic_swap_ulong(volatile unsigned long *uip, unsigned long n)
+{
+	unsigned int cpsr;
+	unsigned long rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip;
+	*uip = n;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_swap_ulong(_p, _n) _atomic_swap_ulong((_p), (_n))
+
+static inline void *
+_atomic_swap_ptr(volatile void *uip, void *n)
+{
+	unsigned int cpsr;
+	void * volatile *uipp = (void * volatile *)uip;
+	void *rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uipp;
+	*uipp = n;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_swap_ptr(_p, _n) _atomic_swap_ptr((_p), (_n))
+
+static inline unsigned int
+_atomic_add_int_nv(volatile unsigned int *uip, unsigned int v)
+{
+	unsigned int cpsr;
+	unsigned int rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip + v;
+	*uip = rv;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_add_int_nv(_p, _v) _atomic_add_int_nv((_p), (_v))
+
+static inline unsigned long
+_atomic_add_long_nv(volatile unsigned long *uip, unsigned long v)
+{
+	unsigned int cpsr;
+	unsigned long rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip + v;
+	*uip = rv;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_add_long_nv(_p, _v) _atomic_add_long_nv((_p), (_v))
+
+static inline unsigned int
+_atomic_sub_int_nv(volatile unsigned int *uip, unsigned int v)
+{
+	unsigned int cpsr;
+	unsigned int rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip - v;
+	*uip = rv;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_sub_int_nv(_p, _v) _atomic_sub_int_nv((_p), (_v))
+
+static inline unsigned long
+_atomic_sub_long_nv(volatile unsigned long *uip, unsigned long v)
+{
+	unsigned int cpsr;
+	unsigned long rv;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	rv = *uip - v;
+	*uip = rv;
+	restore_interrupts(cpsr);
+
+	return (rv);
+}
+#define atomic_sub_long_nv(_p, _v) _atomic_sub_long_nv((_p), (_v))
+
+static inline void
+atomic_setbits_int(volatile unsigned int *uip, unsigned int v)
+{
+	unsigned int cpsr;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	*uip |= v;
+	restore_interrupts(cpsr);
+}
+
+static inline void
+atomic_clearbits_int(volatile unsigned int *uip, unsigned int v)
+{
+	unsigned int cpsr;
+
+	cpsr = disable_interrupts(I32_bit|F32_bit);
+	*uip &= ~v;
+	restore_interrupts(cpsr);
+}
 
 #endif /* defined(_KERNEL) */
 #endif /* _ARM_ATOMIC_H_ */