linux/include/asm-x86_64/segment.h
Vojtech Pavlik c08c820508 [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 <vojtech@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:28 +02:00

46 lines
1.2 KiB
C

#ifndef _ASM_SEGMENT_H
#define _ASM_SEGMENT_H
#include <asm/cache.h>
#define __KERNEL_CS 0x10
#define __KERNEL_DS 0x18
#define __KERNEL32_CS 0x38
/*
* we cannot use the same code segment descriptor for user and kernel
* -- not even in the long flat mode, because of different DPL /kkeil
* The segment offset needs to contain a RPL. Grr. -AK
* GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)
*/
#define __USER32_CS 0x23 /* 4*8+3 */
#define __USER_DS 0x2b /* 5*8+3 */
#define __USER_CS 0x33 /* 6*8+3 */
#define __USER32_DS __USER_DS
#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
#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
#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)
#define IDT_ENTRIES 256
#define GDT_ENTRIES 16
#define GDT_SIZE (GDT_ENTRIES * 8)
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
#endif