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yaml
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r: 98356
b: refs/heads/master
c: 9267b4b
h: refs/heads/master
v: v3
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Ivan Kokshaysky authored and Linus Torvalds committed Jun 20, 2008
1 parent f26a110 commit b5c9c05
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Showing 2 changed files with 72 additions and 2 deletions.
2 changes: 1 addition & 1 deletion [refs]
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---
refs/heads/master: d70ac829b7f42d7ef4f879635c6a772b0b4ed0a2
refs/heads/master: 9267b4b3880d00dc2dab90f1d817c856939114f7
72 changes: 71 additions & 1 deletion trunk/include/asm-alpha/percpu.h
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#ifndef __ALPHA_PERCPU_H
#define __ALPHA_PERCPU_H
#include <linux/compiler.h>
#include <linux/threads.h>

#include <asm-generic/percpu.h>
/*
* Determine the real variable name from the name visible in the
* kernel sources.
*/
#define per_cpu_var(var) per_cpu__##var

#ifdef CONFIG_SMP

/*
* per_cpu_offset() is the offset that has to be added to a
* percpu variable to get to the instance for a certain processor.
*/
extern unsigned long __per_cpu_offset[NR_CPUS];

#define per_cpu_offset(x) (__per_cpu_offset[x])

#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
#ifdef CONFIG_DEBUG_PREEMPT
#define my_cpu_offset per_cpu_offset(smp_processor_id())
#else
#define my_cpu_offset __my_cpu_offset
#endif

#ifndef MODULE
#define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset))
#define PER_CPU_ATTRIBUTES
#else
/*
* To calculate addresses of locally defined variables, GCC uses 32-bit
* displacement from the GP. Which doesn't work for per cpu variables in
* modules, as an offset to the kernel per cpu area is way above 4G.
*
* This forces allocation of a GOT entry for per cpu variable using
* ldq instruction with a 'literal' relocation.
*/
#define SHIFT_PERCPU_PTR(var, offset) ({ \
extern int simple_identifier_##var(void); \
unsigned long __ptr, tmp_gp; \
asm ( "br %1, 1f \n\
1: ldgp %1, 0(%1) \n\
ldq %0, per_cpu__" #var"(%1)\t!literal" \
: "=&r"(__ptr), "=&r"(tmp_gp)); \
(typeof(&per_cpu_var(var)))(__ptr + (offset)); })

#define PER_CPU_ATTRIBUTES __used

#endif /* MODULE */

/*
* A percpu variable may point to a discarded regions. The following are
* established ways to produce a usable pointer from the percpu variable
* offset.
*/
#define per_cpu(var, cpu) \
(*SHIFT_PERCPU_PTR(var, per_cpu_offset(cpu)))
#define __get_cpu_var(var) \
(*SHIFT_PERCPU_PTR(var, my_cpu_offset))
#define __raw_get_cpu_var(var) \
(*SHIFT_PERCPU_PTR(var, __my_cpu_offset))

#else /* ! SMP */

#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var)))
#define __get_cpu_var(var) per_cpu_var(var)
#define __raw_get_cpu_var(var) per_cpu_var(var)

#endif /* SMP */

#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu_var(name)

#endif /* __ALPHA_PERCPU_H */

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