From be44d2aabce2d62f72d5751d1871b6212bf7a1c7 Mon Sep 17 00:00:00 2001 From: Stas Sergeev Date: Thu, 7 Dec 2006 02:14:01 +0100 Subject: [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 Signed-off-by: Andi Kleen Acked-by: Zachary Amsden Acked-by: Chuck Ebbert <76306.1226@compuserve.com> Acked-by: Jan Beulich Cc: Andi Kleen Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Andrew Morton --- include/asm-i386/percpu.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'include/asm-i386/percpu.h') diff --git a/include/asm-i386/percpu.h b/include/asm-i386/percpu.h index 5764afa4b6a..510ae1d3486 100644 --- a/include/asm-i386/percpu.h +++ b/include/asm-i386/percpu.h @@ -1,6 +1,31 @@ #ifndef __ARCH_I386_PERCPU__ #define __ARCH_I386_PERCPU__ +#ifndef __ASSEMBLY__ #include +#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__ */ -- cgit v1.2.3