[coreboot-gerrit] Change in coreboot[master]: soc/intel/tigerlake: Update Cpu Ratio settings

[Srinidhi N Kaushik (Code Review)]

Srinidhi N Kaushik has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/39493 )

Change subject: soc/intel/tigerlake: Update Cpu Ratio settings
......................................................................

soc/intel/tigerlake: Update Cpu Ratio settings

Add config to override CpuRatio or setting CpuRatio to
allowed maximum processor non-turbo ratio.

BUG=151175469
BRANCH=none
TEST=Build and boot tglrvp and observe there is no extra reset
in meminit.

Signed-off-by: Srinidhi N Kaushik 
Change-Id: I2fa883b443d0a4c77d62275faeacd1ed2c67a97c
---
M src/soc/intel/tigerlake/chip.h
M src/soc/intel/tigerlake/romstage/fsp_params_tgl.c
2 files changed, 24 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/93/39493/1

diff --git a/src/soc/intel/tigerlake/chip.h b/src/soc/intel/tigerlake/chip.h
index 9fc70f8..8d593dc 100644
--- a/src/soc/intel/tigerlake/chip.h
+++ b/src/soc/intel/tigerlake/chip.h
@@ -285,6 +285,18 @@
     * This mode makes FSP detect Optane and NVME and set PCIe lane mode
     * accordingly */
    uint8_t HybridStorageMode;
+
+	/*
+	 * 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 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 to not boot with non-turbo max.
+	 */
+	uint8_t cpu_ratio_override;
+
 };

typedef struct soc_intel_tigerlake_config config_t;
diff --git a/src/soc/intel/tigerlake/romstage/fsp_params_tgl.c b/src/soc/intel/tigerlake/romstage/fsp_params_tgl.c
index 072c99e..bfaffd2 100644
--- a/src/soc/intel/tigerlake/romstage/fsp_params_tgl.c
+++ b/src/soc/intel/tigerlake/romstage/fsp_params_tgl.c
@@ -14,10 +14,12 @@
  */

#include <assert.h>
+#include <cpu/x86/msr.h>
 #include <console/console.h>
 #include <fsp/util.h>
 #include <soc/gpio_soc_defs.h>
 #include <soc/iomap.h>
+#include <soc/msr.h>
 #include <soc/pci_devs.h>
 #include <soc/romstage.h>
 #include <soc/soc_chip.h>
@@ -38,6 +40,16 @@
    m_cfg->UserBd = BOARD_TYPE_ULT_ULX;
    m_cfg->RMT = config->RMT;

+	/* CpuRatio Settings */
+	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;
+	}
+
    for (i = 0; i < ARRAY_SIZE(config->PcieRpEnable); i++) {
    	if (config->PcieRpEnable[i])
    		mask |= (1 << i);