From 49a8c8a3adc94c76542389b0bb3dcabec9eb7280 Mon Sep 17 00:00:00 2001 From: Patrick Georgi Date: Mon, 6 Jul 2015 20:50:33 +0200 Subject: [PATCH] sandybridge: provide monotonic timer function This fixes building the ELOG_GSMI feature by using the TSC as time source for the flash drivers. It's not the most precise clock, but should be good enough for the purpose. Change-Id: I2d416c34268236228300a9e868628c35e22bf40c Signed-off-by: Patrick Georgi Reviewed-on: http://review.coreboot.org/10813 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/northbridge/intel/sandybridge/udelay.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/src/northbridge/intel/sandybridge/udelay.c b/src/northbridge/intel/sandybridge/udelay.c index b150253247..7c9838015a 100644 --- a/src/northbridge/intel/sandybridge/udelay.c +++ b/src/northbridge/intel/sandybridge/udelay.c @@ -53,3 +53,23 @@ void udelay(u32 us) } while ((tsc.hi < tsc1.hi) || ((tsc.hi == tsc1.hi) && (tsc.lo < tsc1.lo))); } + +#if CONFIG_LAPIC_MONOTONIC_TIMER && !defined(__PRE_RAM__) +#include + +void timer_monotonic_get(struct mono_time *mt) +{ + tsc_t tsc; + msr_t msr; + u32 fsb = 100, divisor; + u32 d; /* ticks per us */ + + msr = rdmsr(0xce); + divisor = (msr.lo >> 8) & 0xff; + d = fsb * divisor; /* On Core/Core2 this is divided by 4 */ + + tsc = rdtsc(); + + mt->microseconds = (long)((((uint64_t)tsc.hi << 32) | tsc.lo) / d); +} +#endif