Patrick Georgi submitted this change.
soc/intel/cannonlake: Add chip config to override CPU flex ratio
This patch provides options to override descriptor default CPU flex
ratio from coreboot code. cpu_ratio_override to provide the required CPU
ratio.
Note: Don't override the flex ratio if cpu_ratio is 0.
BUG=b:142264107
TEST=Without override flex_ratio is 0 and verified booting to
OS after overriding with flex_ratio value 5.
Change-Id: Ib01650f52f3d402f669e7e7f5b28a648b86f08ec
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36864
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
---
M src/soc/intel/cannonlake/chip.h
M src/soc/intel/cannonlake/romstage/fsp_params.c
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/src/soc/intel/cannonlake/chip.h b/src/soc/intel/cannonlake/chip.h
index 17afdd1..507290f 100644
--- a/src/soc/intel/cannonlake/chip.h
+++ b/src/soc/intel/cannonlake/chip.h
@@ -424,6 +424,19 @@
* Bit 0: MISCCFG_GPDLCGEN
*/
uint8_t gpio_pm[TOTAL_GPIO_COMM];
+
+ /*
+ * Override CPU flex ratio value:
+ * CPU ratio value controls the maximum processor non-turbo ratio.
+ * Valid Range 0 to 63.
+ *
+ * In general descriptor provides option to set default cpu flex ratio.
+ * Default cpu flex ratio is 0 ensures booting with non-turbo max frequency.
+ * Thats the reason FSP skips cpu_ratio override if cpu_ratio is 0.
+ *
+ * Only override CPU flex ratio if don't want to boot with non-turbo max.
+ */
+ uint8_t cpu_ratio_override;
};
typedef struct soc_intel_cannonlake_config config_t;
diff --git a/src/soc/intel/cannonlake/romstage/fsp_params.c b/src/soc/intel/cannonlake/romstage/fsp_params.c
index 996c135..5c74d4a 100644
--- a/src/soc/intel/cannonlake/romstage/fsp_params.c
+++ b/src/soc/intel/cannonlake/romstage/fsp_params.c
@@ -74,10 +74,14 @@
m_cfg->SkipMpInit = !CONFIG_USE_INTEL_FSP_MP_INIT;
#endif
- /* Set CpuRatio to match existing MSR value */
- msr_t flex_ratio;
- flex_ratio = rdmsr(MSR_FLEX_RATIO);
- m_cfg->CpuRatio = (flex_ratio.lo >> 8) & 0xff;
+ if (config->cpu_ratio_override) {
+ m_cfg->CpuRatio = config->cpu_ratio_override;
+ } else {
+ /* Set CpuRatio to match existing MSR value */
+ msr_t flex_ratio;
+ flex_ratio = rdmsr(MSR_FLEX_RATIO);
+ m_cfg->CpuRatio = (flex_ratio.lo >> 8) & 0xff;
+ }
/* If ISH is enabled, enable ISH elements */
if (!dev)
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