mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 21:24:00 +08:00
1e8352784a
2.6.25-rc1 percpu changes broke CONFIG_DEBUG_PREEMPT's per_cpu checking on several architectures. On s390, sparc64 and x86 it's been weakened to not checking at all; whereas on powerpc64 it's become too strict, issuing warnings from __raw_get_cpu_var in io_schedule and init_timer for example. Fix this by weakening powerpc's __my_cpu_offset to use the non-checking local_paca instead of get_paca (which itself contains such a check); and strengthening the generic my_cpu_offset to go the old slow way via smp_processor_id when CONFIG_DEBUG_PREEMPT (debug_smp_processor_id is where all the knowledge of what's correct when lives). Signed-off-by: Hugh Dickins <hugh@veritas.com> Reviewed-by: Mike Travis <travis@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
#ifndef _ASM_GENERIC_PERCPU_H_
|
|
#define _ASM_GENERIC_PERCPU_H_
|
|
#include <linux/compiler.h>
|
|
#include <linux/threads.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.
|
|
*
|
|
* Most arches use the __per_cpu_offset array for those offsets but
|
|
* some arches have their own ways of determining the offset (x86_64, s390).
|
|
*/
|
|
#ifndef __per_cpu_offset
|
|
extern unsigned long __per_cpu_offset[NR_CPUS];
|
|
|
|
#define per_cpu_offset(x) (__per_cpu_offset[x])
|
|
#endif
|
|
|
|
/*
|
|
* Determine the offset for the currently active processor.
|
|
* An arch may define __my_cpu_offset to provide a more effective
|
|
* means of obtaining the offset to the per cpu variables of the
|
|
* current processor.
|
|
*/
|
|
#ifndef __my_cpu_offset
|
|
#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
|
|
#endif
|
|
#ifdef CONFIG_DEBUG_PREEMPT
|
|
#define my_cpu_offset per_cpu_offset(smp_processor_id())
|
|
#else
|
|
#define my_cpu_offset __my_cpu_offset
|
|
#endif
|
|
|
|
/*
|
|
* Add a offset to a pointer but keep the pointer as is.
|
|
*
|
|
* Only S390 provides its own means of moving the pointer.
|
|
*/
|
|
#ifndef SHIFT_PERCPU_PTR
|
|
#define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset))
|
|
#endif
|
|
|
|
/*
|
|
* 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(&per_cpu_var(var), per_cpu_offset(cpu)))
|
|
#define __get_cpu_var(var) \
|
|
(*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset))
|
|
#define __raw_get_cpu_var(var) \
|
|
(*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset))
|
|
|
|
|
|
#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
|
|
extern void setup_per_cpu_areas(void);
|
|
#endif
|
|
|
|
#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 */
|
|
|
|
#ifndef PER_CPU_ATTRIBUTES
|
|
#define PER_CPU_ATTRIBUTES
|
|
#endif
|
|
|
|
#define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
|
|
__typeof__(type) per_cpu_var(name)
|
|
|
|
#endif /* _ASM_GENERIC_PERCPU_H_ */
|