linux/include/asm-i386/percpu.h
Stas Sergeev be44d2aabc [PATCH] i386: espfix cleanup
Clean up the espfix code:

- Introduced PER_CPU() macro to be used from asm
- Introduced GET_DESC_BASE() macro to be used from asm
- Rewrote the fixup code in asm, as calling a C code with the altered %ss
  appeared to be unsafe
- No longer altering the stack from a .fixup section
- 16bit per-cpu stack is no longer used, instead the stack segment base
  is patched the way so that the high word of the kernel and user %esp
  are the same.
- Added the limit-patching for the espfix segment. (Chuck Ebbert)

[jeremy@goop.org: use the x86 scaling addressing mode rather than shifting]
Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Zachary Amsden <zach@vmware.com>
Acked-by: Chuck Ebbert <76306.1226@compuserve.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07 02:14:01 +01:00

32 lines
658 B
C

#ifndef __ARCH_I386_PERCPU__
#define __ARCH_I386_PERCPU__
#ifndef __ASSEMBLY__
#include <asm-generic/percpu.h>
#else
/*
* PER_CPU finds an address of a per-cpu variable.
*
* Args:
* var - variable name
* cpu - 32bit register containing the current CPU number
*
* The resulting address is stored in the "cpu" argument.
*
* Example:
* PER_CPU(cpu_gdt_descr, %ebx)
*/
#ifdef CONFIG_SMP
#define PER_CPU(var, cpu) \
movl __per_cpu_offset(,cpu,4), cpu; \
addl $per_cpu__/**/var, cpu;
#else /* ! SMP */
#define PER_CPU(var, cpu) \
movl $per_cpu__/**/var, cpu;
#endif /* SMP */
#endif /* !__ASSEMBLY__ */
#endif /* __ARCH_I386_PERCPU__ */