[XS] Change in coreboot[main]: mb/google/{rex,ovis}: epp set to 45% for mtl performance expectation

[Sukumar Ghorai (Code Review)]

Sukumar Ghorai has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/79386?usp=email )

Change subject: mb/google/{rex,ovis}: epp set to 45% for mtl performance expectation
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mb/google/{rex,ovis}: epp set to 45% for mtl performance expectation

Default EPP is 50% and is not aggressive enough for MTL performance expectation
in balance_performance mode.
/sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference
    balance_performance
    # iotools rdmsr 0 0x774
    0x0000000080003f06
EPP=45% is giving the required performance in MTL.

Change-Id: I1953994cdb4e9363fdd4b4728e3e5236276c06c8
Signed-off-by: Sukumar Ghorai 
---
M src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb
M src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
2 files changed, 8 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/86/79386/1

diff --git a/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb b/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb
index 3f75b70..aace5ad 100644
--- a/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb
+++ b/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb
@@ -65,6 +65,10 @@
    register "sagv_freq_mhz[3]" = "6400"
    register "sagv_gear[3]" = "4"

+	# set EPP to 45%: 45 * 256/100 = 115 = 0x73
+	register "enable_energy_perf_pref" = "true"
+	register "energy_perf_pref_value" = "0x73"
+
    # Set on-board graphics as primary display
    register "skip_ext_gfx_scan" = "1"

diff --git a/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb b/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
index 162bb64..9f86840 100644
--- a/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
+++ b/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
@@ -62,6 +62,10 @@
    register "sagv_freq_mhz[3]" = "6400"
    register "sagv_gear[3]" = "4"

+	# set EPP to 45%: 45 * 256/100 = 115 = 0x73
+	register "enable_energy_perf_pref" = "true"
+	register "energy_perf_pref_value" = "0x73"
+
    # Set on-board graphics as primary display
    register "skip_ext_gfx_scan" = "1"