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authorVojtech Pavlik <vojtech@suse.cz>2006-09-26 10:52:28 +0200
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 10:52:28 +0200
commitc08c820508233b424deab3302bc404bbecc6493a (patch)
treed6ed79fb2d03513f6c71fc7e47705c4a19512f53 /include/asm-x86_64/segment.h
parenta670fad0adb1cc6202a607d250f10bd380593905 (diff)
[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>
Diffstat (limited to 'include/asm-x86_64/segment.h')
-rw-r--r--include/asm-x86_64/segment.h5
1 files changed, 3 insertions, 2 deletions
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