diff options
Diffstat (limited to 'src/northbridge')
| -rw-r--r-- | src/northbridge/intel/sandybridge/Makefile.inc | 1 | ||||
| -rw-r--r-- | src/northbridge/intel/sandybridge/udelay.c | 55 |
2 files changed, 56 insertions, 0 deletions
diff --git a/src/northbridge/intel/sandybridge/Makefile.inc b/src/northbridge/intel/sandybridge/Makefile.inc index 60765f2da1..cf79459df2 100644 --- a/src/northbridge/intel/sandybridge/Makefile.inc +++ b/src/northbridge/intel/sandybridge/Makefile.inc @@ -42,6 +42,7 @@ romstage-y += early_init.c romstage-y += report_platform.c romstage-y += ../../../arch/x86/lib/walkcbfs.S +smm-$(CONFIG_HAVE_SMI_HANDLER) += udelay.c smm-$(CONFIG_HAVE_SMI_HANDLER) += finalize.c # We don't ship that, but booting without it is bound to fail diff --git a/src/northbridge/intel/sandybridge/udelay.c b/src/northbridge/intel/sandybridge/udelay.c new file mode 100644 index 0000000000..b150253247 --- /dev/null +++ b/src/northbridge/intel/sandybridge/udelay.c @@ -0,0 +1,55 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2007-2008 coresystems GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc. + */ + +#include <delay.h> +#include <stdint.h> +#include <cpu/x86/tsc.h> +#include <cpu/x86/msr.h> + +/** + * Intel Sandy Bridge/Ivy Bridge CPUs always run the TSC at BCLK=100MHz + */ + +void udelay(u32 us) +{ + u32 dword; + tsc_t tsc, tsc1, tscd; + 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 */ + multiply_to_tsc(&tscd, us, d); + + tsc1 = rdtsc(); + dword = tsc1.lo + tscd.lo; + if ((dword < tsc1.lo) || (dword < tscd.lo)) { + tsc1.hi++; + } + tsc1.lo = dword; + tsc1.hi += tscd.hi; + + do { + tsc = rdtsc(); + } while ((tsc.hi < tsc1.hi) + || ((tsc.hi == tsc1.hi) && (tsc.lo < tsc1.lo))); +} |