linux/include/asm-s390/percpu.h
Paul Mackerras bfe5d83419 [PATCH] Define __raw_get_cpu_var and use it
There are several instances of per_cpu(foo, raw_smp_processor_id()), which
is semantically equivalent to __get_cpu_var(foo) but without the warning
that smp_processor_id() can give if CONFIG_DEBUG_PREEMPT is enabled.  For
those architectures with optimized per-cpu implementations, namely ia64,
powerpc, s390, sparc64 and x86_64, per_cpu() turns into more and slower
code than __get_cpu_var(), so it would be preferable to use __get_cpu_var
on those platforms.

This defines a __raw_get_cpu_var(x) macro which turns into per_cpu(x,
raw_smp_processor_id()) on architectures that use the generic per-cpu
implementation, and turns into __get_cpu_var(x) on the architectures that
have an optimized per-cpu implementation.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:01 -07:00

71 lines
2.1 KiB
C

#ifndef __ARCH_S390_PERCPU__
#define __ARCH_S390_PERCPU__
#include <linux/compiler.h>
#include <asm/lowcore.h>
#define __GENERIC_PER_CPU
/*
* s390 uses its own implementation for per cpu data, the offset of
* the cpu local data area is cached in the cpu's lowcore memory.
* For 64 bit module code s390 forces the use of a GOT slot for the
* address of the per cpu variable. This is needed because the module
* may be more than 4G above the per cpu area.
*/
#if defined(__s390x__) && defined(MODULE)
#define __reloc_hide(var,offset) \
(*({ unsigned long *__ptr; \
asm ( "larl %0,per_cpu__"#var"@GOTENT" \
: "=a" (__ptr) : "X" (per_cpu__##var) ); \
(typeof(&per_cpu__##var))((*__ptr) + (offset)); }))
#else
#define __reloc_hide(var, offset) \
(*({ unsigned long __ptr; \
asm ( "" : "=a" (__ptr) : "0" (&per_cpu__##var) ); \
(typeof(&per_cpu__##var)) (__ptr + (offset)); }))
#endif
#ifdef CONFIG_SMP
extern unsigned long __per_cpu_offset[NR_CPUS];
/* Separate out the type, so (int[3], foo) works. */
#define DEFINE_PER_CPU(type, name) \
__attribute__((__section__(".data.percpu"))) \
__typeof__(type) per_cpu__##name
#define __get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
#define __raw_get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
#define per_cpu(var,cpu) __reloc_hide(var,__per_cpu_offset[cpu])
/* A macro to avoid #include hell... */
#define percpu_modcopy(pcpudst, src, size) \
do { \
unsigned int __i; \
for_each_possible_cpu(__i) \
memcpy((pcpudst)+__per_cpu_offset[__i], \
(src), (size)); \
} while (0)
#else /* ! SMP */
#define DEFINE_PER_CPU(type, name) \
__typeof__(type) per_cpu__##name
#define __get_cpu_var(var) __reloc_hide(var,0)
#define __raw_get_cpu_var(var) __reloc_hide(var,0)
#define per_cpu(var,cpu) __reloc_hide(var,0)
#endif /* SMP */
#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
#endif /* __ARCH_S390_PERCPU__ */