diff options
| author | Paul Irofti <pirofti@cvs.openbsd.org> | 2019-08-09 15:20:06 +0000 |
|---|---|---|
| committer | Paul Irofti <pirofti@cvs.openbsd.org> | 2019-08-09 15:20:06 +0000 |
| commit | f3cd69e685aca9d61ae3176dd23e55d44a4fbef4 (patch) | |
| tree | 8845ed61560fe5182016534af9c2102c88785956 /sys/arch/amd64/include/cpu.h | |
| parent | 8876eb727da619d444f5dd33e54fa3d43eaabf60 (diff) | |
Add TSC synchronization for multiprocessor machines.
CPU0 is the reference clock and all others are skewed. During CPU
initialization the clocks synchronize by keeping a registry of each CPU
clock skewness and adapting the TSC read routine accordingly.
This commit also re-enables TSC as the default time source.
Future work includes MSR-based synchronization via IA32_TSC_ADJUST
and perhaps adding a task that is executed periodically to keep the
clocks in sync in case they drift apart.
Inspired from NetBSD.
Tested by many and thoroughly reviewed by kettenis@, thank you!
OK kettenis@, deraadt@
Diffstat (limited to 'sys/arch/amd64/include/cpu.h')
| -rw-r--r-- | sys/arch/amd64/include/cpu.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h index 161aa6e465b..dd41b80fd3a 100644 --- a/sys/arch/amd64/include/cpu.h +++ b/sys/arch/amd64/include/cpu.h @@ -1,4 +1,4 @@ -/* $OpenBSD: cpu.h,v 1.131 2019/05/17 19:07:16 guenther Exp $ */ +/* $OpenBSD: cpu.h,v 1.132 2019/08/09 15:20:05 pirofti Exp $ */ /* $NetBSD: cpu.h,v 1.1 2003/04/26 18:39:39 fvdl Exp $ */ /*- @@ -206,6 +206,8 @@ struct cpu_info { union vmm_cpu_cap ci_vmm_cap; paddr_t ci_vmxon_region_pa; struct vmxon_region *ci_vmxon_region; + + int64_t ci_tsc_skew; /* counter skew vs cpu0 */ }; #define CPUF_BSP 0x0001 /* CPU is the original BSP */ @@ -221,6 +223,7 @@ struct cpu_info { #define CPUF_INVAR_TSC 0x0100 /* CPU has invariant TSC */ #define CPUF_USERXSTATE 0x0200 /* CPU has curproc's xsave state */ +#define CPUF_SYNCTSC 0x0800 /* Synchronize TSC */ #define CPUF_PRESENT 0x1000 /* CPU is present */ #define CPUF_RUNNING 0x2000 /* CPU is running */ #define CPUF_PAUSE 0x4000 /* CPU is paused in DDB */ |