bfe5d83419
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>
74 lines
2.3 KiB
C
74 lines
2.3 KiB
C
#ifndef _ASM_IA64_PERCPU_H
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#define _ASM_IA64_PERCPU_H
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/*
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* Copyright (C) 2002-2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*/
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#define PERCPU_ENOUGH_ROOM PERCPU_PAGE_SIZE
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#ifdef __ASSEMBLY__
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# define THIS_CPU(var) (per_cpu__##var) /* use this to mark accesses to per-CPU variables... */
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#else /* !__ASSEMBLY__ */
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#include <linux/threads.h>
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#ifdef HAVE_MODEL_SMALL_ATTRIBUTE
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# define __SMALL_ADDR_AREA __attribute__((__model__ (__small__)))
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#else
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# define __SMALL_ADDR_AREA
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#endif
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#define DECLARE_PER_CPU(type, name) \
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extern __SMALL_ADDR_AREA __typeof__(type) per_cpu__##name
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/* Separate out the type, so (int[3], foo) works. */
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#define DEFINE_PER_CPU(type, name) \
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__attribute__((__section__(".data.percpu"))) \
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__SMALL_ADDR_AREA __typeof__(type) per_cpu__##name
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/*
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* Pretty much a literal copy of asm-generic/percpu.h, except that percpu_modcopy() is an
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* external routine, to avoid include-hell.
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*/
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#ifdef CONFIG_SMP
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extern unsigned long __per_cpu_offset[NR_CPUS];
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/* Equal to __per_cpu_offset[smp_processor_id()], but faster to access: */
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DECLARE_PER_CPU(unsigned long, local_per_cpu_offset);
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#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))
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#define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __ia64_per_cpu_var(local_per_cpu_offset)))
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#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __ia64_per_cpu_var(local_per_cpu_offset)))
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extern void percpu_modcopy(void *pcpudst, const void *src, unsigned long size);
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extern void setup_per_cpu_areas (void);
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extern void *per_cpu_init(void);
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#else /* ! SMP */
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#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu__##var))
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#define __get_cpu_var(var) per_cpu__##var
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#define __raw_get_cpu_var(var) per_cpu__##var
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#define per_cpu_init() (__phys_per_cpu_start)
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#endif /* SMP */
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#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
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#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
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/*
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* Be extremely careful when taking the address of this variable! Due to virtual
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* remapping, it is different from the canonical address returned by __get_cpu_var(var)!
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* On the positive side, using __ia64_per_cpu_var() instead of __get_cpu_var() is slightly
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* more efficient.
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*/
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#define __ia64_per_cpu_var(var) (per_cpu__##var)
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_IA64_PERCPU_H */
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