[PATCH 18/20] arch,sparc: Fold atomic_ops

From: Peter Zijlstra
Date: Thu May 08 2014 - 10:01:35 EST


Many of the atomic op implementations are the same except for one
instruction; fold the lot into a few CPP macros and reduce LoC.

This also prepares for easy addition of new ops.

Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
arch/sparc/include/asm/atomic_32.h | 19 +--
arch/sparc/include/asm/atomic_64.h | 49 +++++-----
arch/sparc/include/asm/barrier_32.h | 1
arch/sparc/include/asm/processor.h | 2
arch/sparc/kernel/smp_64.c | 2
arch/sparc/lib/atomic32.c | 25 +++--
arch/sparc/lib/atomic_64.S | 175 +++++++++++++++---------------------
arch/sparc/lib/ksyms.c | 25 +++--
8 files changed, 140 insertions(+), 158 deletions(-)

Index: linux-2.6/arch/sparc/include/asm/atomic_32.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/atomic_32.h
+++ linux-2.6/arch/sparc/include/asm/atomic_32.h
@@ -20,7 +20,7 @@

#define ATOMIC_INIT(i) { (i) }

-extern int __atomic_add_return(int, atomic_t *);
+extern int atomic_add_return(int, atomic_t *);
extern int atomic_cmpxchg(atomic_t *, int, int);
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
extern int __atomic_add_unless(atomic_t *, int, int);
@@ -28,15 +28,14 @@ extern void atomic_set(atomic_t *, int);

#define atomic_read(v) (*(volatile int *)&(v)->counter)

-#define atomic_add(i, v) ((void)__atomic_add_return( (int)(i), (v)))
-#define atomic_sub(i, v) ((void)__atomic_add_return(-(int)(i), (v)))
-#define atomic_inc(v) ((void)__atomic_add_return( 1, (v)))
-#define atomic_dec(v) ((void)__atomic_add_return( -1, (v)))
-
-#define atomic_add_return(i, v) (__atomic_add_return( (int)(i), (v)))
-#define atomic_sub_return(i, v) (__atomic_add_return(-(int)(i), (v)))
-#define atomic_inc_return(v) (__atomic_add_return( 1, (v)))
-#define atomic_dec_return(v) (__atomic_add_return( -1, (v)))
+#define atomic_add(i, v) ((void)atomic_add_return( (int)(i), (v)))
+#define atomic_sub(i, v) ((void)atomic_add_return(-(int)(i), (v)))
+#define atomic_inc(v) ((void)atomic_add_return( 1, (v)))
+#define atomic_dec(v) ((void)atomic_add_return( -1, (v)))
+
+#define atomic_sub_return(i, v) (atomic_add_return(-(int)(i), (v)))
+#define atomic_inc_return(v) (atomic_add_return( 1, (v)))
+#define atomic_dec_return(v) (atomic_add_return( -1, (v)))

#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)

Index: linux-2.6/arch/sparc/include/asm/atomic_64.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/atomic_64.h
+++ linux-2.6/arch/sparc/include/asm/atomic_64.h
@@ -20,27 +20,28 @@
#define atomic_set(v, i) (((v)->counter) = i)
#define atomic64_set(v, i) (((v)->counter) = i)

-extern void atomic_add(int, atomic_t *);
-extern void atomic64_add(long, atomic64_t *);
-extern void atomic_sub(int, atomic_t *);
-extern void atomic64_sub(long, atomic64_t *);
-
-extern int atomic_add_ret(int, atomic_t *);
-extern long atomic64_add_ret(long, atomic64_t *);
-extern int atomic_sub_ret(int, atomic_t *);
-extern long atomic64_sub_ret(long, atomic64_t *);
-
-#define atomic_dec_return(v) atomic_sub_ret(1, v)
-#define atomic64_dec_return(v) atomic64_sub_ret(1, v)
+#define ATOMIC_OP(op) \
+extern void atomic_##op(int, atomic_t *); \
+extern void atomic64_##op(long, atomic64_t *);

-#define atomic_inc_return(v) atomic_add_ret(1, v)
-#define atomic64_inc_return(v) atomic64_add_ret(1, v)
+#define ATOMIC_OP_RETURN(op) \
+extern int atomic_##op##_return(int, atomic_t *); \
+extern long atomic64_##op##_return(long, atomic64_t *);

-#define atomic_sub_return(i, v) atomic_sub_ret(i, v)
-#define atomic64_sub_return(i, v) atomic64_sub_ret(i, v)
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)

-#define atomic_add_return(i, v) atomic_add_ret(i, v)
-#define atomic64_add_return(i, v) atomic64_add_ret(i, v)
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define atomic_dec_return(v) atomic_sub_return(1, v)
+#define atomic64_dec_return(v) atomic64_sub_return(1, v)
+
+#define atomic_inc_return(v) atomic_add_return(1, v)
+#define atomic64_inc_return(v) atomic64_add_return(1, v)

/*
* atomic_inc_and_test - increment and test
@@ -53,11 +54,11 @@ extern long atomic64_sub_ret(long, atomi
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)

-#define atomic_sub_and_test(i, v) (atomic_sub_ret(i, v) == 0)
-#define atomic64_sub_and_test(i, v) (atomic64_sub_ret(i, v) == 0)
+#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
+#define atomic64_sub_and_test(i, v) (atomic64_sub_return(i, v) == 0)

-#define atomic_dec_and_test(v) (atomic_sub_ret(1, v) == 0)
-#define atomic64_dec_and_test(v) (atomic64_sub_ret(1, v) == 0)
+#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
+#define atomic64_dec_and_test(v) (atomic64_sub_return(1, v) == 0)

#define atomic_inc(v) atomic_add(1, v)
#define atomic64_inc(v) atomic64_add(1, v)
@@ -65,8 +66,8 @@ extern long atomic64_sub_ret(long, atomi
#define atomic_dec(v) atomic_sub(1, v)
#define atomic64_dec(v) atomic64_sub(1, v)

-#define atomic_add_negative(i, v) (atomic_add_ret(i, v) < 0)
-#define atomic64_add_negative(i, v) (atomic64_add_ret(i, v) < 0)
+#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
+#define atomic64_add_negative(i, v) (atomic64_add_return(i, v) < 0)

#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
Index: linux-2.6/arch/sparc/include/asm/barrier_32.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/barrier_32.h
+++ linux-2.6/arch/sparc/include/asm/barrier_32.h
@@ -1,7 +1,6 @@
#ifndef __SPARC_BARRIER_H
#define __SPARC_BARRIER_H

-#include <asm/processor.h> /* for nop() */
#include <asm-generic/barrier.h>

#endif /* !(__SPARC_BARRIER_H) */
Index: linux-2.6/arch/sparc/include/asm/processor.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/processor.h
+++ linux-2.6/arch/sparc/include/asm/processor.h
@@ -6,6 +6,4 @@
#include <asm/processor_32.h>
#endif

-#define nop() __asm__ __volatile__ ("nop")
-
#endif
Index: linux-2.6/arch/sparc/kernel/smp_64.c
===================================================================
--- linux-2.6.orig/arch/sparc/kernel/smp_64.c
+++ linux-2.6/arch/sparc/kernel/smp_64.c
@@ -1148,7 +1148,7 @@ static unsigned long penguins_are_doing_

void smp_capture(void)
{
- int result = atomic_add_ret(1, &smp_capture_depth);
+ int result = atomic_add_return(1, &smp_capture_depth);

if (result == 1) {
int ncpus = num_online_cpus();
Index: linux-2.6/arch/sparc/lib/atomic32.c
===================================================================
--- linux-2.6.orig/arch/sparc/lib/atomic32.c
+++ linux-2.6/arch/sparc/lib/atomic32.c
@@ -27,18 +27,23 @@ static DEFINE_SPINLOCK(dummy);

#endif /* SMP */

-int __atomic_add_return(int i, atomic_t *v)
-{
- int ret;
- unsigned long flags;
- spin_lock_irqsave(ATOMIC_HASH(v), flags);
+#define ATOMIC_OP(op, cop) \
+int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ int ret; \
+ unsigned long flags; \
+ spin_lock_irqsave(ATOMIC_HASH(v), flags); \
+ \
+ ret = (v->counter cop i); \
+ \
+ spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \
+ return ret; \
+} \
+EXPORT_SYMBOL(atomic_##op##_return);

- ret = (v->counter += i);
+ATOMIC_OP(add, +=)

- spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
- return ret;
-}
-EXPORT_SYMBOL(__atomic_add_return);
+#undef ATOMIC_OP

int atomic_cmpxchg(atomic_t *v, int old, int new)
{
Index: linux-2.6/arch/sparc/lib/atomic_64.S
===================================================================
--- linux-2.6.orig/arch/sparc/lib/atomic_64.S
+++ linux-2.6/arch/sparc/lib/atomic_64.S
@@ -14,109 +14,80 @@
* memory barriers, and a second which returns
* a value and does the barriers.
*/
-ENTRY(atomic_add) /* %o0 = increment, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: lduw [%o1], %g1
- add %g1, %o0, %g7
- cas [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %icc, BACKOFF_LABEL(2f, 1b)
- nop
- retl
- nop
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic_add)
-
-ENTRY(atomic_sub) /* %o0 = decrement, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: lduw [%o1], %g1
- sub %g1, %o0, %g7
- cas [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %icc, BACKOFF_LABEL(2f, 1b)
- nop
- retl
- nop
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic_sub)
-
-ENTRY(atomic_add_ret) /* %o0 = increment, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: lduw [%o1], %g1
- add %g1, %o0, %g7
- cas [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %icc, BACKOFF_LABEL(2f, 1b)
- add %g1, %o0, %g1
- retl
- sra %g1, 0, %o0
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic_add_ret)
-
-ENTRY(atomic_sub_ret) /* %o0 = decrement, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: lduw [%o1], %g1
- sub %g1, %o0, %g7
- cas [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %icc, BACKOFF_LABEL(2f, 1b)
- sub %g1, %o0, %g1
- retl
- sra %g1, 0, %o0
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic_sub_ret)

-ENTRY(atomic64_add) /* %o0 = increment, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: ldx [%o1], %g1
- add %g1, %o0, %g7
- casx [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
- nop
- retl
- nop
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic64_add)
-
-ENTRY(atomic64_sub) /* %o0 = decrement, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: ldx [%o1], %g1
- sub %g1, %o0, %g7
- casx [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
- nop
- retl
- nop
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic64_sub)
-
-ENTRY(atomic64_add_ret) /* %o0 = increment, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: ldx [%o1], %g1
- add %g1, %o0, %g7
- casx [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
- nop
- retl
- add %g1, %o0, %o0
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic64_add_ret)
-
-ENTRY(atomic64_sub_ret) /* %o0 = decrement, %o1 = atomic_ptr */
- BACKOFF_SETUP(%o2)
-1: ldx [%o1], %g1
- sub %g1, %o0, %g7
- casx [%o1], %g1, %g7
- cmp %g1, %g7
- bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
- nop
- retl
- sub %g1, %o0, %o0
-2: BACKOFF_SPIN(%o2, %o3, 1b)
-ENDPROC(atomic64_sub_ret)
+#define ATOMIC_OP(op) \
+ENTRY(atomic_##op) /* %o0 = increment, %o1 = atomic_ptr */ \
+ BACKOFF_SETUP(%o2); \
+1: lduw [%o1], %g1; \
+ op %g1, %o0, %g7; \
+ cas [%o1], %g1, %g7; \
+ cmp %g1, %g7; \
+ bne,pn %icc, BACKOFF_LABEL(2f, 1b); \
+ nop; \
+ retl; \
+ nop; \
+2: BACKOFF_SPIN(%o2, %o3, 1b); \
+ENDPROC(atomic_##op); \
+
+#define ATOMIC_OP_RETURN(op) \
+ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \
+ BACKOFF_SETUP(%o2); \
+1: lduw [%o1], %g1; \
+ op %g1, %o0, %g7; \
+ cas [%o1], %g1, %g7; \
+ cmp %g1, %g7; \
+ bne,pn %icc, BACKOFF_LABEL(2f, 1b); \
+ add %g1, %o0, %g1; \
+ retl; \
+ sra %g1, 0, %o0; \
+2: BACKOFF_SPIN(%o2, %o3, 1b); \
+ENDPROC(atomic_##op##_return);
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define ATOMIC64_OP(op) \
+ENTRY(atomic64_##op) /* %o0 = increment, %o1 = atomic_ptr */ \
+ BACKOFF_SETUP(%o2); \
+1: ldx [%o1], %g1; \
+ op %g1, %o0, %g7; \
+ casx [%o1], %g1, %g7; \
+ cmp %g1, %g7; \
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \
+ nop; \
+ retl; \
+ nop; \
+2: BACKOFF_SPIN(%o2, %o3, 1b); \
+ENDPROC(atomic64_##op); \
+
+#define ATOMIC64_OP_RETURN(op) \
+ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \
+ BACKOFF_SETUP(%o2); \
+1: ldx [%o1], %g1; \
+ op %g1, %o0, %g7; \
+ casx [%o1], %g1, %g7; \
+ cmp %g1, %g7; \
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \
+ nop; \
+ retl; \
+ add %g1, %o0, %o0; \
+2: BACKOFF_SPIN(%o2, %o3, 1b); \
+ENDPROC(atomic64_##op##_return);
+
+#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
+
+ATOMIC64_OPS(add)
+ATOMIC64_OPS(sub)
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP

ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */
BACKOFF_SETUP(%o2)
Index: linux-2.6/arch/sparc/lib/ksyms.c
===================================================================
--- linux-2.6.orig/arch/sparc/lib/ksyms.c
+++ linux-2.6/arch/sparc/lib/ksyms.c
@@ -99,14 +99,23 @@ EXPORT_SYMBOL(___copy_in_user);
EXPORT_SYMBOL(__clear_user);

/* Atomic counter implementation. */
-EXPORT_SYMBOL(atomic_add);
-EXPORT_SYMBOL(atomic_add_ret);
-EXPORT_SYMBOL(atomic_sub);
-EXPORT_SYMBOL(atomic_sub_ret);
-EXPORT_SYMBOL(atomic64_add);
-EXPORT_SYMBOL(atomic64_add_ret);
-EXPORT_SYMBOL(atomic64_sub);
-EXPORT_SYMBOL(atomic64_sub_ret);
+#define ATOMIC_OP(op) \
+EXPORT_SYMBOL(atomic_##op); \
+EXPORT_SYMBOL(atomic64_##op);
+
+#define ATOMIC_OP_RETURN(op) \
+EXPORT_SYMBOL(atomic_##op##_return); \
+EXPORT_SYMBOL(atomic64_##op##_return);
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
EXPORT_SYMBOL(atomic64_dec_if_positive);

/* Atomic bit operations. */


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