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-rw-r--r--src/cpu/intel/haswell/chip.h29
-rw-r--r--src/cpu/intel/haswell/haswell_init.c23
2 files changed, 50 insertions, 2 deletions
diff --git a/src/cpu/intel/haswell/chip.h b/src/cpu/intel/haswell/chip.h
index 6afed37616..7c2df103a0 100644
--- a/src/cpu/intel/haswell/chip.h
+++ b/src/cpu/intel/haswell/chip.h
@@ -3,6 +3,33 @@
/* Magic value used to locate this chip in the device tree */
#define SPEEDSTEP_APIC_MAGIC 0xACAC
+#include <stdbool.h>
+#include <stdint.h>
+
+struct cpu_vr_config {
+ /*
+ * Minimum voltage for C6/C7 state:
+ * 0x67 = 1.6V (full swing)
+ * ...
+ * 0x79 = 1.7V
+ * ...
+ * 0x83 = 1.8V (no swing)
+ */
+ uint8_t cpu_min_vid;
+
+ /*
+ * Set slow VR ramp rate on C-state exit:
+ * 0 = Fast VR ramp rate / 2
+ * 1 = Fast VR ramp rate / 4
+ * 2 = Fast VR ramp rate / 8
+ * 3 = Fast VR ramp rate / 16
+ */
+ uint8_t slow_ramp_rate_set;
+
+ /* Enable slow VR ramp rate */
+ bool slow_ramp_rate_enable;
+};
+
struct cpu_intel_haswell_config {
int c1_battery; /* ACPI C1 on Battery Power */
int c2_battery; /* ACPI C2 on Battery Power */
@@ -13,4 +40,6 @@ struct cpu_intel_haswell_config {
int c3_acpower; /* ACPI C3 on AC Power */
int tcc_offset; /* TCC Activation Offset */
+
+ struct cpu_vr_config vr_config;
};
diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c
index 369ace9b45..dd1970c033 100644
--- a/src/cpu/intel/haswell/haswell_init.c
+++ b/src/cpu/intel/haswell/haswell_init.c
@@ -249,8 +249,17 @@ static u32 pcode_mailbox_read(u32 command)
static void initialize_vr_config(void)
{
+ struct cpu_vr_config vr_config = { 0 };
msr_t msr;
+ const struct device *lapic = dev_find_lapic(SPEEDSTEP_APIC_MAGIC);
+
+ if (lapic && lapic->chip_info) {
+ const struct cpu_intel_haswell_config *conf = lapic->chip_info;
+
+ vr_config = conf->vr_config;
+ }
+
printk(BIOS_DEBUG, "Initializing VR config.\n");
/* Configure VR_CURRENT_CONFIG. */
@@ -280,13 +289,23 @@ static void initialize_vr_config(void)
msr.hi &= ~(1 << (51 - 32));
/* Enable decay mode on C-state entry. */
msr.hi |= (1 << (52 - 32));
+ /* Set the slow ramp rate */
if (haswell_is_ult()) {
- /* Set the slow ramp rate to be fast ramp rate / 4 */
msr.hi &= ~(0x3 << (53 - 32));
- msr.hi |= (0x01 << (53 - 32));
+ /* Configure the C-state exit ramp rate. */
+ if (vr_config.slow_ramp_rate_enable) {
+ /* Configured slow ramp rate. */
+ msr.hi |= ((vr_config.slow_ramp_rate_set & 0x3) << (53 - 32));
+ /* Set exit ramp rate to slow. */
+ msr.hi &= ~(1 << (50 - 32));
+ } else {
+ /* Fast ramp rate / 4. */
+ msr.hi |= (1 << (53 - 32));
+ }
}
/* Set MIN_VID (31:24) to allow CPU to have full control. */
msr.lo &= ~0xff000000;
+ msr.lo |= (vr_config.cpu_min_vid & 0xff) << 24;
wrmsr(MSR_VR_MISC_CONFIG, msr);
/* Configure VR_MISC_CONFIG2 MSR. */