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909ea96468
__get_cpu_var() can be replaced with this_cpu_read and will then use a single read instruction with implied address calculation to access the correct per cpu instance. However, the address of a per cpu variable passed to __this_cpu_read() cannot be determined (since it's an implied address conversion through segment prefixes). Therefore apply this only to uses of __get_cpu_var where the address of the variable is not used. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Hugh Dickins <hughd@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
37 lines
980 B
C
37 lines
980 B
C
/* Fallback per-CPU frame pointer holder
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*
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* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_GENERIC_IRQ_REGS_H
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#define _ASM_GENERIC_IRQ_REGS_H
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#include <linux/percpu.h>
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/*
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* Per-cpu current frame pointer - the location of the last exception frame on
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* the stack
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*/
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DECLARE_PER_CPU(struct pt_regs *, __irq_regs);
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static inline struct pt_regs *get_irq_regs(void)
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{
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return __this_cpu_read(__irq_regs);
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}
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static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs)
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{
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struct pt_regs *old_regs;
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old_regs = __this_cpu_read(__irq_regs);
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__this_cpu_write(__irq_regs, new_regs);
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return old_regs;
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}
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#endif /* _ASM_GENERIC_IRQ_REGS_H */
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