Timothy Pearson (tpearson@raptorengineeringinc.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/12834
-gerrit
commit 15aa2536f51808faece445b0c19955fd0d128fae Author: Timothy Pearson tpearson@raptorengineeringinc.com Date: Tue Jan 5 11:00:49 2016 -0600
cpu/amd/fam10h-15h: Add tsc_freq_mhz() function
The AMD Family 10h/15h processors use a TSC that increments at the P0 core frequency. Allow coreboot to query the TSC frequency.
Change-Id: I73ead4fd4af18991452d59985b667a54689778cd Signed-off-by: Timothy Pearson tpearson@raptorengineeringinc.com --- src/cpu/amd/family_10h-family_15h/Makefile.inc | 1 + src/cpu/amd/family_10h-family_15h/tsc_freq.c | 31 ++++++++++++++++++++++++++ 2 files changed, 32 insertions(+)
diff --git a/src/cpu/amd/family_10h-family_15h/Makefile.inc b/src/cpu/amd/family_10h-family_15h/Makefile.inc index 6cd2513..0f31b79 100644 --- a/src/cpu/amd/family_10h-family_15h/Makefile.inc +++ b/src/cpu/amd/family_10h-family_15h/Makefile.inc @@ -5,6 +5,7 @@ ramstage-y += processor_name.c romstage-y += update_microcode.c romstage-y += ram_calc.c ramstage-y += ram_calc.c +ramstage-y += tsc_freq.c ramstage-y += monotonic_timer.c ramstage-$(CONFIG_HAVE_ACPI_TABLES) += powernow_acpi.c
diff --git a/src/cpu/amd/family_10h-family_15h/tsc_freq.c b/src/cpu/amd/family_10h-family_15h/tsc_freq.c new file mode 100644 index 0000000..2bd6368 --- /dev/null +++ b/src/cpu/amd/family_10h-family_15h/tsc_freq.c @@ -0,0 +1,31 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2015 Raptor Engineeirng + * + * 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. + */ + +#include <stdint.h> +#include <cpu/x86/msr.h> +#include <cpu/x86/tsc.h> + +unsigned long tsc_freq_mhz(void) +{ + msr_t msr; + uint8_t cpufid; + uint8_t cpudid; + + msr = rdmsr(0xc0010064); + cpufid = (msr.lo & 0x3f); + cpudid = (msr.lo & 0x1c0) >> 6; + + return (100 * (cpufid + 0x10)) / (0x01 << cpudid); +}