haswell boards: use libre mrc.bin replacement

courtesy of Angel Pons from the coreboot project

this uses the following patch set from gerrit, as yet
unmerged (in coreboot master) on this date:

    https://review.coreboot.org/c/coreboot/+/64198/5

logic for downloading mrc blobs has been deleted from
lbmk, as this is now completely obsolete (for haswell
boards)

if other platforms are added later that need mrc.bin,
then logic will be re-added again for that

1 files changed, 615 insertions, 0 deletions

diff --git a/resources/coreboot/haswell/patches/0003-haswell-lynxpoint-Add-native-DMI-init.patch b/resources/coreboot/haswell/patches/0003-haswell-lynxpoint-Add-native-DMI-init.patch
new file mode 100644
index 00000000..4e70407c
--- /dev/null
+++ b/resources/coreboot/haswell/patches/0003-haswell-lynxpoint-Add-native-DMI-init.patch
@@ -0,0 +1,615 @@
+From 6ec71c6df97eded010e96c4ea2bd37cc6a13849d Mon Sep 17 00:00:00 2001
+From: Angel Pons <th3fanbus@gmail.com>
+Date: Fri, 6 May 2022 21:56:48 +0200
+Subject: [PATCH 03/26] haswell/lynxpoint: Add native DMI init
+
+Implement native DMI init for Haswell and Lynx Point. This is only
+needed on non-ULT platforms, and only when MRC.bin is not used.
+
+TEST=Verify DMI initialises correctly on Asrock B85M Pro4.
+
+Change-Id: I5fb1a2adc4ffbf0ebbf0d2d3a444055c53765faa
+Signed-off-by: Angel Pons <th3fanbus@gmail.com>
+---
+ src/northbridge/intel/haswell/Makefile.inc    |   1 +
+ src/northbridge/intel/haswell/early_dmi.c     |  96 ++++++++++++
+ src/northbridge/intel/haswell/early_pcie.c    | 121 ++++++++++++++
+ src/northbridge/intel/haswell/haswell.h       |   3 +
+ .../haswell/native_raminit/raminit_native.c   |  15 ++
+ src/northbridge/intel/haswell/vcu_mailbox.c   | 147 ++++++++++++++++++
+ src/northbridge/intel/haswell/vcu_mailbox.h   |  16 ++
+ src/southbridge/intel/lynxpoint/Makefile.inc  |   2 +
+ .../intel/lynxpoint/early_pch_native.c        |  52 +++++++
+ src/southbridge/intel/lynxpoint/pch.h         |  20 ++-
+ 10 files changed, 472 insertions(+), 1 deletion(-)
+ create mode 100644 src/northbridge/intel/haswell/early_dmi.c
+ create mode 100644 src/northbridge/intel/haswell/early_pcie.c
+ create mode 100644 src/northbridge/intel/haswell/vcu_mailbox.c
+ create mode 100644 src/northbridge/intel/haswell/vcu_mailbox.h
+ create mode 100644 src/southbridge/intel/lynxpoint/early_pch_native.c
+
+diff --git a/src/northbridge/intel/haswell/Makefile.inc b/src/northbridge/intel/haswell/Makefile.inc
+index 329f1f7ffe..df0b097296 100644
+--- a/src/northbridge/intel/haswell/Makefile.inc
++++ b/src/northbridge/intel/haswell/Makefile.inc
+@@ -20,6 +20,7 @@ romstage-y += report_platform.c
+ postcar-y += memmap.c
+ 
+ ifeq ($(CONFIG_USE_NATIVE_RAMINIT),y)
++romstage-y += early_dmi.c early_pcie.c vcu_mailbox.c
+ subdirs-y  += native_raminit
+ 
+ else
+diff --git a/src/northbridge/intel/haswell/early_dmi.c b/src/northbridge/intel/haswell/early_dmi.c
+new file mode 100644
+index 0000000000..9941242fd5
+--- /dev/null
++++ b/src/northbridge/intel/haswell/early_dmi.c
+@@ -0,0 +1,96 @@
++/* SPDX-License-Identifier: GPL-2.0-or-later */
++
++#include <console/console.h>
++#include <northbridge/intel/haswell/haswell.h>
++#include <southbridge/intel/lynxpoint/pch.h>
++#include <types.h>
++
++static void dmi_print_link_status(int loglevel)
++{
++	const uint16_t dmilsts = dmibar_read16(DMILSTS);
++	printk(loglevel, "DMI: Running at Gen%u x%u\n", dmilsts & 0xf, dmilsts >> 4 & 0x1f);
++}
++
++#define RETRAIN	(1 << 5)
++
++#define LTRN	(1 << 11)
++
++static void dmi_setup_physical_layer(void)
++{
++	/* Program DMI AFE settings, which are needed for DMI to work */
++	peg_dmi_recipe(false, 0);
++
++	/* Additional DMI programming steps */
++	dmibar_setbits32(0x258, 1 << 29);
++	dmibar_clrsetbits32(0x208, 0x7ff, 0x6b5);
++	dmibar_clrsetbits32(0x22c, 0xffff, 0x2020);
++
++	/* Write SA reference code version */
++	dmibar_write32(0x71c, 0x0000000f);
++	dmibar_write32(0x720, 0x01060200);
++
++	/* We also have to bring up the PCH side of the DMI link */
++	pch_dmi_setup_physical_layer();
++
++	/* Write-once settings */
++	dmibar_clrsetbits32(DMILCAP, 0x3f00f, 2 << 0);
++
++	printk(BIOS_DEBUG, "Retraining DMI at Gen2 speeds...\n");
++	dmi_print_link_status(BIOS_DEBUG);
++
++	/* Retrain link */
++	dmibar_setbits16(DMILCTL, RETRAIN);
++	do {} while (dmibar_read16(DMILSTS) & LTRN);
++	dmi_print_link_status(BIOS_DEBUG);
++
++	/* Retrain link again for DMI Gen2 speeds */
++	dmibar_setbits16(DMILCTL, RETRAIN);
++	do {} while (dmibar_read16(DMILSTS) & LTRN);
++	dmi_print_link_status(BIOS_INFO);
++}
++
++#define VC_ACTIVE	(1U << 31)
++
++#define VCNEGPND	(1 << 1)
++
++#define DMI_VC_CFG(vcid, tcmap)	(VC_ACTIVE | ((vcid) << 24) | (tcmap))
++
++static void dmi_tc_vc_mapping(void)
++{
++	printk(BIOS_DEBUG, "Programming SA  DMI VC/TC mappings...\n");
++
++	if (CONFIG(INTEL_LYNXPOINT_LP))
++		dmibar_setbits8(0xa78, 1 << 1);
++
++	/* Each TC is mapped to one and only one VC */
++	const u32 vc0 = DMI_VC_CFG(0, (1 << 6) | (1 << 5) | (1 << 4) | (1 << 3) | (1 << 0));
++	const u32 vc1 = DMI_VC_CFG(1, (1 << 1));
++	const u32 vcp = DMI_VC_CFG(2, (1 << 2));
++	const u32 vcm = DMI_VC_CFG(7, (1 << 7));
++	dmibar_write32(DMIVC0RCTL, vc0);
++	dmibar_write32(DMIVC1RCTL, vc1);
++	dmibar_write32(DMIVCPRCTL, vcp);
++	dmibar_write32(DMIVCMRCTL, vcm);
++
++	/* Set Extended VC Count (EVCC) to 1 if VC1 is active */
++	dmibar_clrsetbits8(DMIPVCCAP1, 7, !!(vc1 & VC_ACTIVE));
++
++	/*
++	 * We also have to program the PCH side of the DMI link. Since both ends
++	 * must use the same Virtual Channel settings, we pass them as arguments.
++	 */
++	pch_dmi_tc_vc_mapping(vc0, vc1, vcp, vcm);
++
++	printk(BIOS_DEBUG, "Waiting for SA  DMI VC negotiation... ");
++	do {} while (dmibar_read16(DMIVC0RSTS) & VCNEGPND);
++	do {} while (dmibar_read16(DMIVC1RSTS) & VCNEGPND);
++	do {} while (dmibar_read16(DMIVCPRSTS) & VCNEGPND);
++	do {} while (dmibar_read16(DMIVCMRSTS) & VCNEGPND);
++	printk(BIOS_DEBUG, "done!\n");
++}
++
++void dmi_early_init(void)
++{
++	dmi_setup_physical_layer();
++	dmi_tc_vc_mapping();
++}
+diff --git a/src/northbridge/intel/haswell/early_pcie.c b/src/northbridge/intel/haswell/early_pcie.c
+new file mode 100644
+index 0000000000..d3940e3fac
+--- /dev/null
++++ b/src/northbridge/intel/haswell/early_pcie.c
+@@ -0,0 +1,121 @@
++/* SPDX-License-Identifier: GPL-2.0-or-later */
++
++#include <console/console.h>
++#include <device/pci_def.h>
++#include <device/pci_mmio_cfg.h>
++#include <device/pci_ops.h>
++#include <northbridge/intel/haswell/haswell.h>
++#include <northbridge/intel/haswell/vcu_mailbox.h>
++#include <types.h>
++
++#define PEG_DEV(func)		PCI_DEV(0, 1, func)
++
++#define MAX_PEG_FUNC		3
++
++static void peg_dmi_unset_and_set_mask_pcicfg(
++	volatile union pci_bank *const bank,
++	const uint32_t offset,
++	const uint32_t unset_mask,
++	const uint32_t set_mask,
++	const uint32_t shift,
++	const bool valid)
++{
++	if (!valid)
++		return;
++
++	volatile uint32_t *const addr = &bank->reg32[offset / sizeof(uint32_t)];
++	clrsetbits32(addr, unset_mask << shift, set_mask << shift);
++}
++
++static void peg_dmi_unset_and_set_mask_common(
++	const bool is_peg,
++	const uint32_t offset,
++	const uint32_t unset,
++	const uint32_t set,
++	const uint32_t shift,
++	const bool valid)
++{
++	const uint32_t unset_mask = unset << shift;
++	const uint32_t   set_mask =   set << shift;
++	if (is_peg) {
++		for (uint8_t i = 0; i < MAX_PEG_FUNC; i++)
++			pci_update_config32(PEG_DEV(i), offset, ~unset_mask, set_mask);
++	} else {
++		dmibar_clrsetbits32(offset, unset_mask, set_mask);
++	}
++}
++
++static void peg_dmi_unset_and_set_mask_vcu_mmio(
++	const uint32_t addr,
++	const uint32_t unset_mask,
++	const uint32_t set_mask,
++	const uint32_t shift,
++	const bool valid)
++{
++	if (!valid)
++		return;
++
++	vcu_update_mmio(addr, ~(unset_mask << shift), set_mask << shift);
++}
++
++#define BUNDLE_STEP	0x20
++
++static void *const dmibar = (void *)(uintptr_t)CONFIG_FIXED_DMIBAR_MMIO_BASE;
++
++void peg_dmi_recipe(const bool is_peg, const pci_devfn_t dev)
++{
++	const bool always = true;
++	const bool is_dmi = !is_peg;
++
++	/* Treat DMIBAR and PEG devices the same way */
++	volatile union pci_bank *const bank = is_peg ? pci_map_bus(dev) : dmibar;
++
++	const size_t bundles = (is_peg ? 8 : 2) * BUNDLE_STEP;
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP) {
++		/* These are actually per-lane */
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0xa00 + i, 0x1f, 0x0c,  0, always);
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0xa10 + i, 0x1f, 0x0c,  0, always);
++	}
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x904 + i, 0x1f, 0x02,  0, is_peg);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x904 + i, 0x1f, 0x03,  5, is_peg);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x90c + i, 0x3f, 0x09,  5, always);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x90c + i, 0x0f, 0x05, 21, is_peg);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x910 + i, 0x0f, 0x08,  6, is_peg);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x910 + i, 0x0f, 0x00, 10, always);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x910 + i, 0x07, 0x00, 18, always);
++
++	peg_dmi_unset_and_set_mask_vcu_mmio(0x0c008001, 0x1f, 0x03, 25, is_peg);
++	peg_dmi_unset_and_set_mask_vcu_mmio(0x0c0c8001, 0x3f, 0x00, 23, is_dmi);
++
++	peg_dmi_unset_and_set_mask_pcicfg(bank, 0xc28, 0x1f, 0x13, 18, always);
++
++	peg_dmi_unset_and_set_mask_common(is_peg, 0xc38, 0x01, 0x00,  6, always);
++	peg_dmi_unset_and_set_mask_common(is_peg, 0x260, 0x03, 0x02,  0, always);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x900 + i, 0x03, 0x00, 26, always);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x904 + i, 0x03, 0x03, 10, always);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x90c + i, 0x1f, 0x07, 25, is_peg);
++
++	for (size_t i = 0; i < bundles; i += BUNDLE_STEP)
++		peg_dmi_unset_and_set_mask_pcicfg(bank, 0x91c + i, 0x07, 0x05, 27, is_peg);
++}
+diff --git a/src/northbridge/intel/haswell/haswell.h b/src/northbridge/intel/haswell/haswell.h
+index 1b29f6baf0..30b4abd0a7 100644
+--- a/src/northbridge/intel/haswell/haswell.h
++++ b/src/northbridge/intel/haswell/haswell.h
+@@ -34,6 +34,9 @@ void haswell_early_initialization(void);
+ void haswell_late_initialization(void);
+ void haswell_unhide_peg(void);
+ 
++void dmi_early_init(void);
++void peg_dmi_recipe(const bool is_peg, const pci_devfn_t dev);
++
+ void report_platform_info(void);
+ 
+ struct acpi_rsdp;
+diff --git a/src/northbridge/intel/haswell/native_raminit/raminit_native.c b/src/northbridge/intel/haswell/native_raminit/raminit_native.c
+index 1aafdf8659..0938e026e3 100644
+--- a/src/northbridge/intel/haswell/native_raminit/raminit_native.c
++++ b/src/northbridge/intel/haswell/native_raminit/raminit_native.c
+@@ -1,7 +1,19 @@
+ /* SPDX-License-Identifier: GPL-2.0-or-later */
+ 
+ #include <console/console.h>
++#include <northbridge/intel/haswell/haswell.h>
+ #include <northbridge/intel/haswell/raminit.h>
++#include <types.h>
++
++static bool early_init_native(int s3resume)
++{
++	printk(BIOS_DEBUG, "Starting native platform initialisation\n");
++
++	if (!CONFIG(INTEL_LYNXPOINT_LP))
++		dmi_early_init();
++
++	return false;
++}
+ 
+ void perform_raminit(const int s3resume)
+ {
+@@ -9,6 +21,9 @@ void perform_raminit(const int s3resume)
+ 	 * See, this function's name is a lie. There are more things to
+ 	 * do that memory initialisation, but they are relatively easy.
+ 	 */
++	const bool cpu_replaced = early_init_native(s3resume);
++
++	(void)cpu_replaced;
+ 
+ 	/** TODO: Implement the required magic **/
+ 	die("NATIVE RAMINIT: More Magic (tm) required.\n");
+diff --git a/src/northbridge/intel/haswell/vcu_mailbox.c b/src/northbridge/intel/haswell/vcu_mailbox.c
+new file mode 100644
+index 0000000000..aead144023
+--- /dev/null
++++ b/src/northbridge/intel/haswell/vcu_mailbox.c
+@@ -0,0 +1,147 @@
++/* SPDX-License-Identifier: GPL-2.0-or-later */
++
++#include <assert.h>
++#include <console/console.h>
++#include <delay.h>
++#include <northbridge/intel/haswell/haswell.h>
++#include <northbridge/intel/haswell/vcu_mailbox.h>
++#include <stdint.h>
++
++/*
++ * This is a library for the VCU (Validation Control Unit) mailbox. This
++ * mailbox is primarily used to adjust some magic PCIe tuning parameters.
++ *
++ * There are two revisions of the VCU mailbox. Rev1 is specific to Haswell
++ * stepping A0, and all other steppings use Rev2. Haswell stepping A0 CPUs
++ * are early Engineering Samples with undocumented errata, and most likely
++ * need special microcode updates to boot. Thus, the code does not support
++ * VCU mailbox Rev1, because no one should need it anymore.
++ */
++
++#define VCU_MAILBOX_INTERFACE	0x6c00
++#define VCU_MAILBOX_DATA	0x6c04
++
++#define VCU_RUN_BUSY		(1 << 31)
++
++enum vcu_opcode {
++	VCU_OPCODE_READ_VCU_API_VER_ID	= 0x01,
++	VCU_OPCODE_OPEN_SEQ		= 0x02,
++	VCU_OPCODE_CLOSE_SEQ		= 0x03,
++	VCU_OPCODE_READ_DATA		= 0x07,
++	VCU_OPCODE_WRITE_DATA		= 0x08,
++	VCU_OPCODE_READ_CSR		= 0x13,
++	VCU_OPCODE_WRITE_CSR		= 0x14,
++	VCU_OPCODE_READ_MMIO		= 0x15,
++	VCU_OPCODE_WRITE_MMIO		= 0x16,
++};
++
++enum vcu_sequence {
++	SEQ_ID_READ_CSR		= 0x1,
++	SEQ_ID_WRITE_CSR	= 0x2,
++	SEQ_ID_READ_MMIO	= 0x3,
++	SEQ_ID_WRITE_MMIO	= 0x4,
++};
++
++#define VCU_RESPONSE_MASK		0xffff
++#define VCU_RESPONSE_SUCCESS		0x40
++#define VCU_RESPONSE_BUSY		0x80
++#define VCU_RESPONSE_THREAD_UNAVAILABLE	0x82
++#define VCU_RESPONSE_ILLEGAL		0x90
++
++/* FIXME: Use timer API */
++static void send_vcu_command(const enum vcu_opcode opcode, const uint32_t data)
++{
++	for (unsigned int i = 0; i < 10; i++) {
++		mchbar_write32(VCU_MAILBOX_DATA, data);
++		mchbar_write32(VCU_MAILBOX_INTERFACE, opcode | VCU_RUN_BUSY);
++		uint32_t vcu_interface;
++		for (unsigned int j = 0; j < 100; j++) {
++			vcu_interface = mchbar_read32(VCU_MAILBOX_INTERFACE);
++			if (!(vcu_interface & VCU_RUN_BUSY))
++				break;
++
++			udelay(10);
++		}
++		if (vcu_interface & VCU_RUN_BUSY)
++			continue;
++
++		if ((vcu_interface & VCU_RESPONSE_MASK) == VCU_RESPONSE_SUCCESS)
++			return;
++	}
++	printk(BIOS_ERR, "VCU: Failed to send command\n");
++}
++
++static enum vcu_opcode get_register_opcode(enum vcu_sequence seq)
++{
++	switch (seq) {
++	case SEQ_ID_READ_CSR:
++		return VCU_OPCODE_READ_CSR;
++	case SEQ_ID_WRITE_CSR:
++		return VCU_OPCODE_WRITE_CSR;
++	case SEQ_ID_READ_MMIO:
++		return VCU_OPCODE_READ_MMIO;
++	case SEQ_ID_WRITE_MMIO:
++		return VCU_OPCODE_WRITE_MMIO;
++	default:
++		return dead_code_t(enum vcu_opcode);
++	}
++}
++
++static enum vcu_opcode get_data_opcode(enum vcu_sequence seq)
++{
++	switch (seq) {
++	case SEQ_ID_READ_CSR:
++	case SEQ_ID_READ_MMIO:
++		return VCU_OPCODE_READ_DATA;
++	case SEQ_ID_WRITE_CSR:
++	case SEQ_ID_WRITE_MMIO:
++		return VCU_OPCODE_WRITE_DATA;
++	default:
++		return dead_code_t(enum vcu_opcode);
++	}
++}
++
++static uint32_t send_vcu_sequence(uint32_t addr, enum vcu_sequence seq, uint32_t wr_data)
++{
++	send_vcu_command(VCU_OPCODE_OPEN_SEQ, seq);
++
++	send_vcu_command(get_register_opcode(seq), addr);
++
++	send_vcu_command(get_data_opcode(seq), wr_data);
++
++	const uint32_t rd_data = mchbar_read32(VCU_MAILBOX_DATA);
++
++	send_vcu_command(VCU_OPCODE_CLOSE_SEQ, seq);
++
++	return rd_data;
++}
++
++uint32_t vcu_read_csr(uint32_t addr)
++{
++	return send_vcu_sequence(addr, SEQ_ID_READ_CSR, 0);
++}
++
++void vcu_write_csr(uint32_t addr, uint32_t data)
++{
++	send_vcu_sequence(addr, SEQ_ID_WRITE_CSR, data);
++}
++
++void vcu_update_csr(uint32_t addr, uint32_t andvalue, uint32_t orvalue)
++{
++	vcu_write_csr(addr, (vcu_read_csr(addr) & andvalue) | orvalue);
++}
++
++uint32_t vcu_read_mmio(uint32_t addr)
++{
++	return send_vcu_sequence(addr, SEQ_ID_READ_MMIO, 0);
++}
++
++void vcu_write_mmio(uint32_t addr, uint32_t data)
++{
++	send_vcu_sequence(addr, SEQ_ID_WRITE_MMIO, data);
++}
++
++void vcu_update_mmio(uint32_t addr, uint32_t andvalue, uint32_t orvalue)
++{
++	vcu_write_mmio(addr, (vcu_read_mmio(addr) & andvalue) | orvalue);
++}
+diff --git a/src/northbridge/intel/haswell/vcu_mailbox.h b/src/northbridge/intel/haswell/vcu_mailbox.h
+new file mode 100644
+index 0000000000..ba0a62e486
+--- /dev/null
++++ b/src/northbridge/intel/haswell/vcu_mailbox.h
+@@ -0,0 +1,16 @@
++/* SPDX-License-Identifier: GPL-2.0-or-later */
++
++#ifndef HASWELL_VCU_MAILBOX_H
++#define HASWELL_VCU_MAILBOX_H
++
++#include <stdint.h>
++
++uint32_t vcu_read_csr(uint32_t addr);
++void vcu_write_csr(uint32_t addr, uint32_t data);
++void vcu_update_csr(uint32_t addr, uint32_t andvalue, uint32_t orvalue);
++
++uint32_t vcu_read_mmio(uint32_t addr);
++void vcu_write_mmio(uint32_t addr, uint32_t data);
++void vcu_update_mmio(uint32_t addr, uint32_t andvalue, uint32_t orvalue);
++
++#endif /* HASWELL_VCU_MAILBOX_H */
+diff --git a/src/southbridge/intel/lynxpoint/Makefile.inc b/src/southbridge/intel/lynxpoint/Makefile.inc
+index 02022d348d..b8503ac8bc 100644
+--- a/src/southbridge/intel/lynxpoint/Makefile.inc
++++ b/src/southbridge/intel/lynxpoint/Makefile.inc
+@@ -37,6 +37,8 @@ bootblock-y += early_pch.c
+ romstage-y += early_usb.c early_me.c me_status.c early_pch.c
+ romstage-y += pmutil.c
+ 
++romstage-$(CONFIG_USE_NATIVE_RAMINIT) += early_pch_native.c
++
+ ifeq ($(CONFIG_INTEL_LYNXPOINT_LP),y)
+ romstage-y += lp_gpio.c
+ ramstage-y += lp_gpio.c
+diff --git a/src/southbridge/intel/lynxpoint/early_pch_native.c b/src/southbridge/intel/lynxpoint/early_pch_native.c
+new file mode 100644
+index 0000000000..c28ddfcf5d
+--- /dev/null
++++ b/src/southbridge/intel/lynxpoint/early_pch_native.c
+@@ -0,0 +1,52 @@
++/* SPDX-License-Identifier: GPL-2.0-or-later */
++
++#include <console/console.h>
++#include <device/pci_ops.h>
++#include <southbridge/intel/lynxpoint/pch.h>
++#include <types.h>
++
++void pch_dmi_setup_physical_layer(void)
++{
++	/* FIXME: We need to make sure the SA supports Gen2 as well */
++	if ((RCBA32(0x21a4) & 0x0f) == 0x02) {
++		/* Set Gen 2 Common Clock N_FTS */
++		RCBA32_AND_OR(0x2340, ~0x00ff0000, 0x3a << 16);
++
++		/* Set Target Link Speed to DMI Gen2 */
++		RCBA8_AND_OR(DLCTL2, ~0x07, 0x02);
++	}
++}
++
++#define VC_ACTIVE	(1U << 31)
++
++#define VCNEGPND	(1 << 1)
++
++void pch_dmi_tc_vc_mapping(const u32 vc0, const u32 vc1, const u32 vcp, const u32 vcm)
++{
++	printk(BIOS_DEBUG, "Programming PCH DMI VC/TC mappings...\n");
++
++	RCBA32_AND_OR(CIR0050, ~(0xf << 20), 2 << 20);
++	if (vcp & VC_ACTIVE)
++		RCBA32_OR(CIR0050, 1 << 19 | 1 << 17);
++
++	RCBA32(CIR0050);	/* Posted Write */
++
++	/* Use the same virtual channel mapping on both ends of the DMI link */
++	RCBA32(V0CTL) = vc0;
++	RCBA32(V1CTL) = vc1;
++	RCBA32(V1CTL);		/* Posted Write */
++	RCBA32(VPCTL) = vcp;
++	RCBA32(VPCTL);		/* Posted Write */
++	RCBA32(VMCTL) = vcm;
++
++	/* Lock the registers */
++	RCBA32_OR(CIR0050, 1U << 31);
++	RCBA32(CIR0050);	/* Posted Write */
++
++	printk(BIOS_DEBUG, "Waiting for PCH DMI VC negotiation... ");
++	do {} while (RCBA16(V0STS) & VCNEGPND);
++	do {} while (RCBA16(V1STS) & VCNEGPND);
++	do {} while (RCBA16(VPSTS) & VCNEGPND);
++	do {} while (RCBA16(VMSTS) & VCNEGPND);
++	printk(BIOS_DEBUG, "done!\n");
++}
+diff --git a/src/southbridge/intel/lynxpoint/pch.h b/src/southbridge/intel/lynxpoint/pch.h
+index 7d9fc6d6af..b5e0c2a830 100644
+--- a/src/southbridge/intel/lynxpoint/pch.h
++++ b/src/southbridge/intel/lynxpoint/pch.h
+@@ -113,6 +113,9 @@ enum pch_platform_type {
+ 	PCH_TYPE_ULT	 = 5,
+ };
+ 
++void pch_dmi_setup_physical_layer(void);
++void pch_dmi_tc_vc_mapping(u32 vc0, u32 vc1, u32 vcp, u32 vcm);
++
+ void usb_ehci_sleep_prepare(pci_devfn_t dev, u8 slp_typ);
+ void usb_ehci_disable(pci_devfn_t dev);
+ void usb_xhci_sleep_prepare(pci_devfn_t dev, u8 slp_typ);
+@@ -406,9 +409,10 @@ void mainboard_config_rcba(void);
+ 
+ /* Southbridge IO BARs */
+ 
++#define PMBASE			0x40
+ #define GPIOBASE		0x48
+ 
+-#define PMBASE		0x40
++#define CIR0050		0x0050	/* 32bit */
+ 
+ #define RPC		0x0400	/* 32bit */
+ #define RPFN		0x0404	/* 32bit */
+@@ -431,6 +435,20 @@ void mainboard_config_rcba(void);
+ #define IOTR2		0x1e90	/* 64bit */
+ #define IOTR3		0x1e98	/* 64bit */
+ 
++#define V0CTL		0x2014	/* 32bit */
++#define V0STS		0x201a	/* 16bit */
++
++#define V1CTL		0x2020	/* 32bit */
++#define V1STS		0x2026	/* 16bit */
++
++#define VPCTL		0x2030	/* 32bit */
++#define VPSTS		0x2038	/* 16bit */
++
++#define VMCTL		0x2040	/* 32bit */
++#define VMSTS		0x2048	/* 16bit */
++
++#define DLCTL2		0x21b0
++
+ #define TCTL		0x3000	/*  8bit */
+ 
+ #define NOINT		0
+-- 
+2.39.2
+