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-rw-r--r--src/cpu/amd/family_10h-family_15h/Makefile.inc2
-rw-r--r--src/cpu/amd/family_10h-family_15h/tsc_freq.c37
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);
+}