From c08c820508233b424deab3302bc404bbecc6493a Mon Sep 17 00:00:00 2001 From: Vojtech Pavlik Date: Tue, 26 Sep 2006 10:52:28 +0200 Subject: [PATCH] Add the vgetcpu vsyscall This patch adds a vgetcpu vsyscall, which depending on the CPU RDTSCP capability uses either the RDTSCP or CPUID to obtain a CPU and node numbers and pass them to the program. AK: Lots of changes over Vojtech's original code: Better prototype for vgetcpu() It's better to pass the cpu / node numbers as separate arguments to avoid mistakes when going from SMP to NUMA. Also add a fast time stamp based cache using a user supplied argument to speed things more up. Use fast method from Chuck Ebbert to retrieve node/cpu from GDT limit instead of CPUID Made sure RDTSCP init is always executed after node is known. Drop printk Signed-off-by: Vojtech Pavlik Signed-off-by: Andi Kleen --- include/asm-x86_64/segment.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/asm-x86_64/segment.h') diff --git a/include/asm-x86_64/segment.h b/include/asm-x86_64/segment.h index d4bed33fb32..334ddcdd8f9 100644 --- a/include/asm-x86_64/segment.h +++ b/include/asm-x86_64/segment.h @@ -20,15 +20,16 @@ #define __USER_CS 0x33 /* 6*8+3 */ #define __USER32_DS __USER_DS -#define GDT_ENTRY_TLS 1 #define GDT_ENTRY_TSS 8 /* needs two entries */ #define GDT_ENTRY_LDT 10 /* needs two entries */ #define GDT_ENTRY_TLS_MIN 12 #define GDT_ENTRY_TLS_MAX 14 -/* 15 free */ #define GDT_ENTRY_TLS_ENTRIES 3 +#define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */ +#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3) + /* TLS indexes for 64bit - hardcoded in arch_prctl */ #define FS_TLS 0 #define GS_TLS 1 -- cgit v1.2.3