[coreboot-gerrit] Change in coreboot[master]: cpu/intel/common: correct MSR for the Nominal Performance in CPPC

[Michael Niewöhner (Code Review)]

Michael Niewöhner has submitted this change. ( https://review.coreboot.org/c/coreboot/+/46464 )

Change subject: cpu/intel/common: correct MSR for the Nominal Performance in CPPC
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cpu/intel/common: correct MSR for the Nominal Performance in CPPC

The "Nominal Performance" is not the same as the "Guaranteed
Performance", but is defined as the performance a processor can deliver
continously under ideal environmental conditions.

According to edk2, this is the "Maximum Non-Turbo Ratio", which needs to
be read from MSR_PLATFORM_INFO instead of IA32_HWP_CAPABILITIES.

Correct the entry in the CPPC package.

Test: dumped SSDT from Supermicro X11SSM-F and checked decompiled
version

Change-Id: Ic2c27fd3e14af18aa4101c0acd7a5ede15d1f3a9
Signed-off-by: Michael Niewöhner 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46464
Reviewed-by: Subrata Banik 
Reviewed-by: Tim Wawrzynczak 
Tested-by: build bot (Jenkins) 
---
M src/cpu/intel/common/common_init.c
M src/include/cpu/intel/msr.h
2 files changed, 11 insertions(+), 7 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Subrata Banik: Looks good to me, approved
  Tim Wawrzynczak: Looks good to me, approved

diff --git a/src/cpu/intel/common/common_init.c b/src/cpu/intel/common/common_init.c
index 3ea8f36..c5f43ef 100644
--- a/src/cpu/intel/common/common_init.c
+++ b/src/cpu/intel/common/common_init.c
@@ -131,13 +131,6 @@
    config->regs[CPPC_HIGHEST_PERF] = msr;

/*
-	 * Nominal Performance -> Guaranteed Performance:
-	 * ResourceTemplate(){Register(FFixedHW, 0x08, 0x08, 0x771, 0x04,)},
-	 */
-	msr.bit_offset = 8;
-	config->regs[CPPC_NOMINAL_PERF] = msr;
-
-	/*
     * Lowest Nonlinear Performance -> Most Efficient Performance:
     * ResourceTemplate(){Register(FFixedHW, 0x08, 0x10, 0x771, 0x04,)},
     */
@@ -158,6 +151,15 @@
    msr.bit_offset = 8;
    config->regs[CPPC_GUARANTEED_PERF] = msr;

+	msr.addrl = MSR_PLATFORM_INFO;
+
+	/*
+	 * Nominal Performance -> Maximum Non-Turbo Ratio:
+	 * ResourceTemplate(){Register(FFixedHW, 0x08, 0x08, 0xce, 0x04,)},
+	 */
+	msr.bit_offset = 8;
+	config->regs[CPPC_NOMINAL_PERF] = msr;
+
    msr.addrl = IA32_HWP_REQUEST;

/*
diff --git a/src/include/cpu/intel/msr.h b/src/include/cpu/intel/msr.h
index a2165f3..da0f0bb 100644
--- a/src/include/cpu/intel/msr.h
+++ b/src/include/cpu/intel/msr.h
@@ -12,4 +12,6 @@
 #define MSR_PIC_MSG_CONTROL	0x2e
 #define  TPR_UPDATES_DISABLE	(1 << 10)

+#define MSR_PLATFORM_INFO	0xce
+
 #endif /* CPU_INTEL_MSR_H */