diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cpu/amd/family_10h-family_15h/Makefile.inc | 2 | ||||
| -rw-r--r-- | src/cpu/amd/family_10h-family_15h/tsc_freq.c | 37 |
2 files changed, 39 insertions, 0 deletions
diff --git a/src/cpu/amd/family_10h-family_15h/Makefile.inc b/src/cpu/amd/family_10h-family_15h/Makefile.inc index 6cd2513a6d..f10f7327e4 100644 --- a/src/cpu/amd/family_10h-family_15h/Makefile.inc +++ b/src/cpu/amd/family_10h-family_15h/Makefile.inc @@ -3,6 +3,8 @@ ramstage-y += model_10xxx_init.c ramstage-y += processor_name.c romstage-y += update_microcode.c +romstage-y += tsc_freq.c +ramstage-y += tsc_freq.c romstage-y += ram_calc.c ramstage-y += ram_calc.c ramstage-y += monotonic_timer.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 0000000000..afd7dab69f --- /dev/null +++ b/src/cpu/amd/family_10h-family_15h/tsc_freq.c @@ -0,0 +1,37 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2016 Raptor Engineering + * + * 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; + + /* On Family 10h/15h CPUs the TSC increments + * at the P0 clock rate. Read the P0 clock + * frequency from the P0 MSR and convert + * to MHz. See also the Family 15h BKDG + * Rev. 3.14 page 569. + */ + msr = rdmsr(0xc0010064); + cpufid = (msr.lo & 0x3f); + cpudid = (msr.lo & 0x1c0) >> 6; + + return (100 * (cpufid + 0x10)) / (0x01 << cpudid); +} |