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authorAngel Pons <th3fanbus@gmail.com>2020-07-23 02:37:12 +0200
committerAngel Pons <th3fanbus@gmail.com>2020-07-28 10:54:29 +0000
commit598ec6af9814a0b94fcbbafa9dde2197185ad4c3 (patch)
treebeb1a4cac769f6caa0b001fc8f4bfec8f6665612
parentb82b4314ad32dcdb02cb5db1efcda3417aa8fe5d (diff)
downloadcoreboot-598ec6af9814a0b94fcbbafa9dde2197185ad4c3.tar.xz
nb/intel/haswell: Enable DMI ASPM
On Haswell platforms, the processor and the PCH are two separate dies, and communicate through a high-speed bus. This is DMI (Direct Media Interface) on traditional two-package platforms, but single-package Haswell LP variants use OPI (On-Package Interconnect) instead. Since OPI is not routed through the mainboard, most link parameters are static and cannot be changed. OPI self-initializes on boot, anyway. However, DMI needs to be initialized in firmware. On Haswell, the MRC initializes the physical DMI link, but things like topology and power management need to be configured as well. And we don't do that properly. We enable ASPM on the PCH side of the DMI link, but not on the SA side. Both sides need to use the same settings, so enable DMI ASPM on the SA. Clearing the error status bits needs to be done on all Haswell variants. Tested on Asrock B85M Pro4, still boots. Change-Id: Ie97ff56eec9f928cfd2d5d43a287f3e0d2fbf3cf Signed-off-by: Angel Pons <th3fanbus@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/43743 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
-rw-r--r--src/northbridge/intel/haswell/haswell.h10
-rw-r--r--src/northbridge/intel/haswell/northbridge.c42
2 files changed, 52 insertions, 0 deletions
diff --git a/src/northbridge/intel/haswell/haswell.h b/src/northbridge/intel/haswell/haswell.h
index 1255cac5d6..5e28336b0c 100644
--- a/src/northbridge/intel/haswell/haswell.h
+++ b/src/northbridge/intel/haswell/haswell.h
@@ -127,11 +127,21 @@
#define DMILCTL 0x088 /* 16bit */
#define DMILSTS 0x08a /* 16bit */
+#define DMILCTL2 0x098 /* 16bit */
+
#define DMICTL1 0x0f0 /* 32bit */
#define DMICTL2 0x0fc /* 32bit */
+#define DMIUESTS 0x1c4 /* 32bit */
+#define DMICESTS 0x1d0 /* 32bit */
+
#define DMICC 0x208 /* 32bit */
+#define DMIL0SLAT 0x22c /* 32bit */
+#define DMILLTC 0x238 /* 32bit */
+
+#define DMI_AFE_PM_TMR 0xc28 /* 32bit */
+
#define DMIDRCCFG 0xeb4 /* 32bit */
#ifndef __ASSEMBLER__
diff --git a/src/northbridge/intel/haswell/northbridge.c b/src/northbridge/intel/haswell/northbridge.c
index ef7742e523..5c9ef744b1 100644
--- a/src/northbridge/intel/haswell/northbridge.c
+++ b/src/northbridge/intel/haswell/northbridge.c
@@ -418,10 +418,52 @@ static void disable_devices(void)
pci_write_config32(host_dev, DEVEN, deven);
}
+static void northbridge_dmi_init(void)
+{
+ const bool is_haswell_h = !CONFIG(INTEL_LYNXPOINT_LP);
+
+ u16 reg16;
+ u32 reg32;
+
+ /* Steps prior to DMI ASPM */
+ if (is_haswell_h) {
+ /* Configure DMI De-Emphasis */
+ reg16 = DMIBAR16(DMILCTL2);
+ reg16 |= (1 << 6); /* 0b: -6.0 dB, 1b: -3.5 dB */
+ DMIBAR16(DMILCTL2) = reg16;
+
+ reg32 = DMIBAR32(DMIL0SLAT);
+ reg32 |= (1 << 31);
+ DMIBAR32(DMIL0SLAT) = reg32;
+
+ reg32 = DMIBAR32(DMILLTC);
+ reg32 |= (1 << 29);
+ DMIBAR32(DMILLTC) = reg32;
+
+ reg32 = DMIBAR32(DMI_AFE_PM_TMR);
+ reg32 &= ~0x1f;
+ reg32 |= 0x13;
+ DMIBAR32(DMI_AFE_PM_TMR) = reg32;
+ }
+
+ /* Clear error status bits */
+ DMIBAR32(DMIUESTS) = 0xffffffff;
+ DMIBAR32(DMICESTS) = 0xffffffff;
+
+ if (is_haswell_h) {
+ /* Enable ASPM L0s and L1 on SA link, should happen before PCH link */
+ reg16 = DMIBAR16(DMILCTL);
+ reg16 |= (1 << 1) | (1 << 0);
+ DMIBAR16(DMILCTL) = reg16;
+ }
+}
+
static void northbridge_init(struct device *dev)
{
u8 bios_reset_cpl, pair;
+ northbridge_dmi_init();
+
/* Enable Power Aware Interrupt Routing. */
pair = MCHBAR8(INTRDIRCTL);
pair &= ~0x7; /* Clear 2:0 */