77 lines
2.2 KiB
C
77 lines
2.2 KiB
C
#ifndef __ALPHA_PERCPU_H
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#define __ALPHA_PERCPU_H
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#include <linux/compiler.h>
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#include <linux/threads.h>
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/*
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* Determine the real variable name from the name visible in the
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* kernel sources.
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*/
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#define per_cpu_var(var) per_cpu__##var
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#ifdef CONFIG_SMP
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/*
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* per_cpu_offset() is the offset that has to be added to a
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* percpu variable to get to the instance for a certain processor.
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*/
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extern unsigned long __per_cpu_offset[NR_CPUS];
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#define per_cpu_offset(x) (__per_cpu_offset[x])
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#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
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#ifdef CONFIG_DEBUG_PREEMPT
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#define my_cpu_offset per_cpu_offset(smp_processor_id())
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#else
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#define my_cpu_offset __my_cpu_offset
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#endif
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#ifndef MODULE
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#define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset))
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#define PER_CPU_ATTRIBUTES
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#else
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/*
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* To calculate addresses of locally defined variables, GCC uses 32-bit
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* displacement from the GP. Which doesn't work for per cpu variables in
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* modules, as an offset to the kernel per cpu area is way above 4G.
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*
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* This forces allocation of a GOT entry for per cpu variable using
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* ldq instruction with a 'literal' relocation.
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*/
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#define SHIFT_PERCPU_PTR(var, offset) ({ \
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extern int simple_identifier_##var(void); \
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unsigned long __ptr, tmp_gp; \
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asm ( "br %1, 1f \n\
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1: ldgp %1, 0(%1) \n\
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ldq %0, per_cpu__" #var"(%1)\t!literal" \
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: "=&r"(__ptr), "=&r"(tmp_gp)); \
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(typeof(&per_cpu_var(var)))(__ptr + (offset)); })
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#define PER_CPU_ATTRIBUTES __used
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#endif /* MODULE */
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/*
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* A percpu variable may point to a discarded regions. The following are
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* established ways to produce a usable pointer from the percpu variable
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* offset.
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*/
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#define per_cpu(var, cpu) \
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(*SHIFT_PERCPU_PTR(var, per_cpu_offset(cpu)))
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#define __get_cpu_var(var) \
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(*SHIFT_PERCPU_PTR(var, my_cpu_offset))
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#define __raw_get_cpu_var(var) \
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(*SHIFT_PERCPU_PTR(var, __my_cpu_offset))
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#else /* ! SMP */
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#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var)))
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#define __get_cpu_var(var) per_cpu_var(var)
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#define __raw_get_cpu_var(var) per_cpu_var(var)
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#endif /* SMP */
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#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu_var(name)
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#endif /* __ALPHA_PERCPU_H */
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