Relocate the x86_64 percpu variables to begin at zero. Then we can directly use the x86_32 percpu operations. x86_32 offsets %fs by __per_cpu_start. x86_64 has %gs pointing directly to the pda and the per cpu area if they start at zero. Access to the pda with the x86_64 pda operations is still possible in addition to access to the per cpu variables using x86_32 percpu operations. Hopefully this is helpful for arch integration. Signed-off-by: Christoph Lameter --- arch/x86/Kconfig | 5 +++++ arch/x86/kernel/setup64.c | 4 ++-- arch/x86/kernel/vmlinux_64.lds.S | 1 + include/asm-x86/percpu.h | 12 +++++++++++- 4 files changed, 19 insertions(+), 3 deletions(-) Index: linux-2.6.24-rc3-mm2/include/asm-x86/percpu.h =================================================================== --- linux-2.6.24-rc3-mm2.orig/include/asm-x86/percpu.h 2007-11-29 22:13:54.806575787 -0800 +++ linux-2.6.24-rc3-mm2/include/asm-x86/percpu.h 2007-11-29 22:21:42.383571603 -0800 @@ -17,6 +17,12 @@ #define per_cpu_offset(x) (__per_cpu_offset(x)) +#define __percpu_seg "%%gs:" + +#else + +#define __percpu_seg "" + #endif #include @@ -81,6 +87,11 @@ DECLARE_PER_CPU(struct x8664_pda, pda); /* We can use this directly for local CPU (faster). */ DECLARE_PER_CPU(unsigned long, this_cpu_off); +#endif /* __ASSEMBLY__ */ +#endif /* !CONFIG_X86_64 */ + +#ifndef __ASSEMBLY__ + /* For arch-specific code, we can use direct single-insn ops (they * don't give an lvalue though). */ extern void __bad_percpu_size(void); @@ -138,5 +149,4 @@ extern void __bad_percpu_size(void); #define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val) #define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val) #endif /* !__ASSEMBLY__ */ -#endif /* !CONFIG_X86_64 */ #endif /* _ASM_X86_PERCPU_H_ */ Index: linux-2.6.24-rc3-mm2/arch/x86/Kconfig =================================================================== --- linux-2.6.24-rc3-mm2.orig/arch/x86/Kconfig 2007-11-29 22:05:39.003576212 -0800 +++ linux-2.6.24-rc3-mm2/arch/x86/Kconfig 2007-11-29 22:12:53.942575452 -0800 @@ -123,6 +123,11 @@ config GENERIC_TIME_VSYSCALL config ARCH_SETS_UP_PER_CPU_AREA def_bool X86_64 +config PERCPU_ZERO_BASED + bool + depends on X86_64 && SMP + default y + config ZONE_DMA32 bool default X86_64 Index: linux-2.6.24-rc3-mm2/arch/x86/kernel/setup64.c =================================================================== --- linux-2.6.24-rc3-mm2.orig/arch/x86/kernel/setup64.c 2007-11-29 22:12:08.962826086 -0800 +++ linux-2.6.24-rc3-mm2/arch/x86/kernel/setup64.c 2007-11-29 22:12:53.942575452 -0800 @@ -111,11 +111,11 @@ void __init setup_per_cpu_areas(void) } if (!ptr) panic("Cannot allocate cpu data for CPU %d\n", i); - memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start); + memcpy(ptr, __per_cpu_load, __per_cpu_size); /* Relocate the pda */ memcpy(ptr, cpu_pda(i), sizeof(struct x8664_pda)); cpu_pda(i) = (struct x8664_pda *)ptr; - cpu_pda(i)->data_offset = ptr - __per_cpu_start; + cpu_pda(i)->data_offset = (unsigned long)ptr; } /* Fix up pda for this processor .... */ pda_init(0); Index: linux-2.6.24-rc3-mm2/arch/x86/kernel/vmlinux_64.lds.S =================================================================== --- linux-2.6.24-rc3-mm2.orig/arch/x86/kernel/vmlinux_64.lds.S 2007-11-29 22:05:38.987576338 -0800 +++ linux-2.6.24-rc3-mm2/arch/x86/kernel/vmlinux_64.lds.S 2007-11-29 22:12:53.930825752 -0800 @@ -16,6 +16,7 @@ jiffies_64 = jiffies; _proxy_pda = 1; PHDRS { text PT_LOAD FLAGS(5); /* R_E */ + percpu PT_LOAD FLAGS(4); /* R__ */ data PT_LOAD FLAGS(7); /* RWE */ user PT_LOAD FLAGS(7); /* RWE */ data.init PT_LOAD FLAGS(7); /* RWE */ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/