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authorPatrick Rudolph <patrick.rudolph@9elements.com>2020-07-26 14:23:37 +0200
committerPatrick Georgi <pgeorgi@google.com>2020-11-22 22:31:40 +0000
commitb01ac7e26453677318776885d4ab870f59553ae6 (patch)
tree8cc66d66f6135a56c857c86397caa6e35e856096 /src/cpu/intel/common
parent44cfde02d5d694a6f0eced12333d2350acb498d1 (diff)
downloadcoreboot-b01ac7e26453677318776885d4ab870f59553ae6.tar.xz
cpu/intel/common: Fill cpu voltage in SMBIOS tables
Introduce a weak function to let the platform code provide the processor voltage in 100mV units. Implement the function on Intel platforms using the MSR_PERF_STATUS msr. On other platforms the processor voltage still reads as unknown. Tested on Intel CFL. The CPU voltage is correctly advertised. Change-Id: I31a7efcbeede50d986a1c096a4a59a316e09f825 Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/43904 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com> Reviewed-by: Jonathan Zhang <jonzhang@fb.com> Reviewed-by: Nico Huber <nico.h@gmx.de>
Diffstat (limited to 'src/cpu/intel/common')
-rw-r--r--src/cpu/intel/common/Kconfig3
-rw-r--r--src/cpu/intel/common/Makefile.inc1
-rw-r--r--src/cpu/intel/common/voltage.c12
3 files changed, 16 insertions, 0 deletions
diff --git a/src/cpu/intel/common/Kconfig b/src/cpu/intel/common/Kconfig
index 01f2721b59..7f9033cf65 100644
--- a/src/cpu/intel/common/Kconfig
+++ b/src/cpu/intel/common/Kconfig
@@ -32,6 +32,9 @@ config CPU_INTEL_COMMON_TIMEBASE
endif
+config CPU_INTEL_COMMON_VOLTAGE
+ bool
+
config CPU_INTEL_COMMON_SMM
bool
default y if CPU_INTEL_COMMON
diff --git a/src/cpu/intel/common/Makefile.inc b/src/cpu/intel/common/Makefile.inc
index 8b81a121d3..530ecee009 100644
--- a/src/cpu/intel/common/Makefile.inc
+++ b/src/cpu/intel/common/Makefile.inc
@@ -1,5 +1,6 @@
ramstage-$(CONFIG_CPU_INTEL_COMMON) += common_init.c
ramstage-$(CONFIG_CPU_INTEL_COMMON) += hyperthreading.c
+ramstage-$(CONFIG_CPU_INTEL_COMMON_VOLTAGE) += voltage.c
ifeq ($(CONFIG_CPU_INTEL_COMMON_TIMEBASE),y)
bootblock-y += fsb.c
diff --git a/src/cpu/intel/common/voltage.c b/src/cpu/intel/common/voltage.c
new file mode 100644
index 0000000000..38951a06db
--- /dev/null
+++ b/src/cpu/intel/common/voltage.c
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <cpu/x86/msr.h>
+#include <smbios.h>
+
+/* This is not an architectural MSR. */
+#define MSR_PERF_STATUS 0x198
+
+unsigned int smbios_cpu_get_voltage(void)
+{
+ return (rdmsr(MSR_PERF_STATUS).hi & 0xffff) * 10 / 8192;
+}