mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 01:51:53 +00:00
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>
38 lines
980 B
C
38 lines
980 B
C
/* Fallback per-CPU frame pointer holder
|
|
*
|
|
* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#ifndef _ASM_GENERIC_IRQ_REGS_H
|
|
#define _ASM_GENERIC_IRQ_REGS_H
|
|
|
|
#include <linux/percpu.h>
|
|
|
|
/*
|
|
* Per-cpu current frame pointer - the location of the last exception frame on
|
|
* the stack
|
|
*/
|
|
DECLARE_PER_CPU(struct pt_regs *, __irq_regs);
|
|
|
|
static inline struct pt_regs *get_irq_regs(void)
|
|
{
|
|
return __this_cpu_read(__irq_regs);
|
|
}
|
|
|
|
static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs)
|
|
{
|
|
struct pt_regs *old_regs;
|
|
|
|
old_regs = __this_cpu_read(__irq_regs);
|
|
__this_cpu_write(__irq_regs, new_regs);
|
|
return old_regs;
|
|
}
|
|
|
|
#endif /* _ASM_GENERIC_IRQ_REGS_H */
|