[PATCH] atomic_long_t & include/asm-generic/atomic.h V2

Several counters already have the need to use 64 atomic variables on 64 bit
platforms (see mm_counter_t in sched.h).  We have to do ugly ifdefs to fall
back to 32 bit atomic on 32 bit platforms.

The VM statistics patch that I am working on will also make more extensive
use of atomic64.

This patch introduces a new type atomic_long_t by providing definitions in
asm-generic/atomic.h that works similar to the c "long" type.  Its 32 bits
on 32 bit platforms and 64 bits on 64 bit platforms.

Also cleans up the determination of the mm_counter_t in sched.h.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-alpha/atomic.h

@@ -216,4 +216,5 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
 #define smp_mb__before_atomic_inc()	smp_mb()
 #define smp_mb__after_atomic_inc()	smp_mb()
 
+#include <asm-generic/atomic.h>
 #endif /* _ALPHA_ATOMIC_H */

include/asm-arm/atomic.h

@@ -205,5 +205,6 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif
 #endif

include/asm-arm26/atomic.h

@@ -118,5 +118,6 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif
 #endif

include/asm-cris/atomic.h

@@ -156,4 +156,5 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 #define smp_mb__before_atomic_inc()    barrier()
 #define smp_mb__after_atomic_inc()     barrier()
 
+#include <asm-generic/atomic.h>
 #endif

include/asm-frv/atomic.h

@@ -426,4 +426,5 @@ extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);
 })
 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 
+#include <asm-generic/atomic.h>
 #endif /* _ASM_ATOMIC_H */

include/asm-generic/atomic.h

+#ifndef _ASM_GENERIC_ATOMIC_H
+#define _ASM_GENERIC_ATOMIC_H
+/*
+ * Copyright (C) 2005 Silicon Graphics, Inc.
+ *	Christoph Lameter <clameter@sgi.com>
+ *
+ * Allows to provide arch independent atomic definitions without the need to
+ * edit all arch specific atomic.h files.
+ */
+
+
+/*
+ * Suppport for atomic_long_t
+ *
+ * Casts for parameters are avoided for existing atomic functions in order to
+ * avoid issues with cast-as-lval under gcc 4.x and other limitations that the
+ * macros of a platform may have.
+ */
+
+#if BITS_PER_LONG == 64
+
+typedef atomic64_t atomic_long_t;
+
+#define ATOMIC_LONG_INIT(i)	ATOMIC64_INIT(i)
+
+static inline long atomic_long_read(atomic_long_t *l)
+{
+	atomic64_t *v = (atomic64_t *)l;
+
+	return (long)atomic64_read(v);
+}
+
+static inline void atomic_long_set(atomic_long_t *l, long i)
+{
+	atomic64_t *v = (atomic64_t *)l;
+
+	atomic_set(v, i);
+}
+
+static inline void atomic_long_inc(atomic_long_t *l)
+{
+	atomic64_t *v = (atomic64_t *)l;
+
+	atomic64_inc(v);
+}
+
+static inline void atomic_long_dec(atomic_long_t *l)
+{
+	atomic64_t *v = (atomic64_t *)l;
+
+	atomic64_dec(v);
+}
+
+static inline void atomic_long_add(long i, atomic_long_t *l)
+{
+	atomic64_t *v = (atomic64_t *)l;
+
+	atomic64_add(i, v);
+}
+
+static inline void atomic_long_sub(long i, atomic_long_t *l)
+{
+	atomic64_t *v = (atomic64_t *)l;
+
+	atomic64_sub(i, v);
+}
+
+#else
+
+typedef atomic_t atomic_long_t;
+
+#define ATOMIC_LONG_INIT(i)	ATOMIC_INIT(i)
+static inline long atomic_long_read(atomic_long_t *l)
+{
+	atomic_t *v = (atomic_t *)l;
+
+	return (long)atomic_read(v);
+}
+
+static inline void atomic_long_set(atomic_long_t *l, long i)
+{
+	atomic_t *v = (atomic_t *)l;
+
+	atomic_set(v, i);
+}
+
+static inline void atomic_long_inc(atomic_long_t *l)
+{
+	atomic_t *v = (atomic_t *)l;
+
+	atomic_inc(v);
+}
+
+static inline void atomic_long_dec(atomic_long_t *l)
+{
+	atomic_t *v = (atomic_t *)l;
+
+	atomic_dec(v);
+}
+
+static inline void atomic_long_add(long i, atomic_long_t *l)
+{
+	atomic_t *v = (atomic_t *)l;
+
+	atomic_add(i, v);
+}
+
+static inline void atomic_long_sub(long i, atomic_long_t *l)
+{
+	atomic_t *v = (atomic_t *)l;
+
+	atomic_sub(i, v);
+}
+
+#endif
+#endif

include/asm-h8300/atomic.h

@@ -137,4 +137,5 @@ static __inline__ void atomic_set_mask(unsigned long mask, unsigned long *v)
 #define smp_mb__before_atomic_inc()    barrier()
 #define smp_mb__after_atomic_inc() barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* __ARCH_H8300_ATOMIC __ */

include/asm-i386/atomic.h

@@ -254,4 +254,5 @@ __asm__ __volatile__(LOCK "orl %0,%1" \
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif

include/asm-ia64/atomic.h

@@ -192,4 +192,5 @@ atomic64_add_negative (__s64 i, atomic64_t *v)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* _ASM_IA64_ATOMIC_H */

include/asm-m32r/atomic.h

@@ -313,4 +313,5 @@ static __inline__ void atomic_set_mask(unsigned long  mask, atomic_t *addr)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif	/* _ASM_M32R_ATOMIC_H */

include/asm-m68k/atomic.h

@@ -157,4 +157,5 @@ static inline void atomic_set_mask(unsigned long mask, unsigned long *v)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* __ARCH_M68K_ATOMIC __ */

include/asm-m68knommu/atomic.h

@@ -143,4 +143,5 @@ static inline int atomic_sub_return(int i, atomic_t * v)
 #define atomic_dec_return(v) atomic_sub_return(1,(v))
 #define atomic_inc_return(v) atomic_add_return(1,(v))
 
+#include <asm-generic/atomic.h>
 #endif /* __ARCH_M68KNOMMU_ATOMIC __ */

include/asm-mips/atomic.h

@@ -713,4 +713,5 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
 #define smp_mb__before_atomic_inc()	smp_mb()
 #define smp_mb__after_atomic_inc()	smp_mb()
 
+#include <asm-generic/atomic.h>
 #endif /* _ASM_ATOMIC_H */

include/asm-parisc/atomic.h

@@ -216,4 +216,5 @@ static __inline__ int atomic_read(const atomic_t *v)
 #define smp_mb__before_atomic_inc()	smp_mb()
 #define smp_mb__after_atomic_inc()	smp_mb()
 
+#include <asm-generic/atomic.h>
 #endif

include/asm-powerpc/atomic.h

@@ -402,5 +402,6 @@ static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
 
 #endif /* __powerpc64__ */
 
+#include <asm-generic/atomic.h>
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_ATOMIC_H_ */

include/asm-s390/atomic.h

@@ -215,5 +215,6 @@ atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
 #define smp_mb__before_atomic_inc()	smp_mb()
 #define smp_mb__after_atomic_inc()	smp_mb()
 
+#include <asm-generic/atomic.h>
 #endif /* __KERNEL__ */
 #endif /* __ARCH_S390_ATOMIC__  */

include/asm-sh/atomic.h

@@ -140,4 +140,5 @@ static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* __ASM_SH_ATOMIC_H */

include/asm-sh64/atomic.h

@@ -152,4 +152,5 @@ static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* __ASM_SH64_ATOMIC_H */

include/asm-sparc/atomic.h

@@ -159,4 +159,5 @@ static inline int __atomic24_sub(int i, atomic24_t *v)
 
 #endif /* !(__KERNEL__) */
 
+#include <asm-generic/atomic.h>
 #endif /* !(__ARCH_SPARC_ATOMIC__) */

include/asm-sparc64/atomic.h

@@ -96,4 +96,5 @@ extern int atomic64_sub_ret(int, atomic64_t *);
 #define smp_mb__after_atomic_inc()	barrier()
 #endif
 
+#include <asm-generic/atomic.h>
 #endif /* !(__ARCH_SPARC64_ATOMIC__) */

include/asm-v850/atomic.h

@@ -126,4 +126,5 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* __V850_ATOMIC_H__ */

include/asm-x86_64/atomic.h

@@ -424,4 +424,5 @@ __asm__ __volatile__(LOCK "orl %0,%1" \
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif

include/asm-xtensa/atomic.h

@@ -286,6 +286,7 @@ static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif /* __KERNEL__ */
 
 #endif /* _XTENSA_ATOMIC_H */

include/linux/sched.h

@@ -254,25 +254,12 @@ extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
  * The mm counters are not protected by its page_table_lock,
  * so must be incremented atomically.
  */
-#ifdef ATOMIC64_INIT
-#define set_mm_counter(mm, member, value) atomic64_set(&(mm)->_##member, value)
-#define get_mm_counter(mm, member) ((unsigned long)atomic64_read(&(mm)->_##member))
-#define add_mm_counter(mm, member, value) atomic64_add(value, &(mm)->_##member)
-#define inc_mm_counter(mm, member) atomic64_inc(&(mm)->_##member)
-#define dec_mm_counter(mm, member) atomic64_dec(&(mm)->_##member)
-typedef atomic64_t mm_counter_t;
-#else /* !ATOMIC64_INIT */
-/*
- * The counters wrap back to 0 at 2^32 * PAGE_SIZE,
- * that is, at 16TB if using 4kB page size.
- */
-#define set_mm_counter(mm, member, value) atomic_set(&(mm)->_##member, value)
-#define get_mm_counter(mm, member) ((unsigned long)atomic_read(&(mm)->_##member))
-#define add_mm_counter(mm, member, value) atomic_add(value, &(mm)->_##member)
-#define inc_mm_counter(mm, member) atomic_inc(&(mm)->_##member)
-#define dec_mm_counter(mm, member) atomic_dec(&(mm)->_##member)
-typedef atomic_t mm_counter_t;
-#endif /* !ATOMIC64_INIT */
+#define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
+#define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
+#define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
+#define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
+#define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
+typedef atomic_long_t mm_counter_t;
 
 #else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
 /*