Change in coreboot[master]: soc/intel/xeon_sp/cpx: add chip operation and PCIe enumeration

[Philipp Deppenwiese (Code Review)]

Philipp Deppenwiese has submitted this change. ( https://review.coreboot.org/c/coreboot/+/40110 )

Change subject: soc/intel/xeon_sp/cpx: add chip operation and PCIe enumeration
......................................................................

soc/intel/xeon_sp/cpx: add chip operation and PCIe enumeration

Add PCIe enumeration and resource assignment/allocation.

Xeon-SP processor family has split IIO design, where PCIe domain 0 is
split into multiple stacks. Each stack has its own resource ranges (eg.
IO resource, mem32 resource, mem64 resource). The stack itself is not
PCIe device, it does not have config space to be probed/programmed.

The stack is programmed by FSP. coreboot needs to take into account of
stack when doing PCIe enumeration and resource allocation.

Current coreboot PCIe resource allocator does not support the concept of
split IIO stack, thus entire support is done locally in this patch.

In near future, improvements will be done, first generalize for xeon-sp,
then generalize for coreboot PCIe device code.

Signed-off-by: Jonathan Zhang 
Signed-off-by: Reddy Chagam 
Change-Id: If461b1dc1f313d98b676dc9e91d08a1dbb9cb388
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40110
Tested-by: build bot (Jenkins) 
Reviewed-by: Aaron Durbin 
Reviewed-by: Philipp Deppenwiese 
---
M src/soc/intel/xeon_sp/cpx/Makefile.inc
M src/soc/intel/xeon_sp/cpx/chip.c
M src/soc/intel/xeon_sp/cpx/chip.h
M src/soc/intel/xeon_sp/cpx/include/soc/irq.h
A src/soc/intel/xeon_sp/cpx/include/soc/soc_util.h
A src/soc/intel/xeon_sp/cpx/soc_util.c
M src/soc/intel/xeon_sp/include/soc/util.h
7 files changed, 642 insertions(+), 12 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Aaron Durbin: Looks good to me, approved
  Philipp Deppenwiese: Looks good to me, approved

diff --git a/src/soc/intel/xeon_sp/cpx/Makefile.inc b/src/soc/intel/xeon_sp/cpx/Makefile.inc
index 6c0d6c0..54004a5 100644
--- a/src/soc/intel/xeon_sp/cpx/Makefile.inc
+++ b/src/soc/intel/xeon_sp/cpx/Makefile.inc
@@ -8,7 +8,7 @@
 subdirs-y += ../../../../cpu/intel/microcode

romstage-y += romstage.c
-ramstage-y += chip.c acpi.c cpu.c
+ramstage-y += chip.c acpi.c cpu.c soc_util.c

CPPFLAGS_common += -I$(src)/soc/intel/xeon_sp/cpx/include -I$(src)/soc/intel/xeon_sp/cpx

diff --git a/src/soc/intel/xeon_sp/cpx/chip.c b/src/soc/intel/xeon_sp/cpx/chip.c
index c19c0cf..19ebe47 100644
--- a/src/soc/intel/xeon_sp/cpx/chip.c
+++ b/src/soc/intel/xeon_sp/cpx/chip.c
@@ -1,18 +1,492 @@
 /* SPDX-License-Identifier: GPL-2.0-only */

#include <arch/ioapic.h>
+#include <assert.h>
 #include <console/console.h>
 #include <cpu/x86/lapic.h>
 #include <device/pci.h>
 #include <fsp/api.h>
 #include <intelblocks/p2sb.h>
+#include <post.h>
 #include <soc/cpu.h>
 #include <soc/ramstage.h>
 #include <soc/pm.h>
+#include <soc/soc_util.h>
+#include <stdlib.h>

/* C620 IOAPIC has 120 redirection entries */
 #define C620_IOAPIC_REDIR_ENTRIES		120

+struct pci_resource {
+	struct device        *dev;
+	struct resource      *res;
+	struct pci_resource  *next;
+};
+
+struct stack_dev_resource {
+	uint8_t                   align;
+	struct pci_resource       *children;
+	struct stack_dev_resource *next;
+};
+
+typedef enum {
+	RES_TYPE_IO = 0,
+	RES_TYPE_NONPREF_MEM,
+	RES_TYPE_PREF_MEM,
+	MAX_RES_TYPES
+} ResType;
+
+static ResType get_res_type(uint64_t flags)
+{
+	if (flags & IORESOURCE_IO)
+		return RES_TYPE_IO;
+	if (flags & IORESOURCE_MEM) {
+		if (flags & IORESOURCE_PREFETCH) {
+			printk(BIOS_DEBUG, "%s:%d flags: 0x%llx\n", __func__, __LINE__, flags);
+			return RES_TYPE_PREF_MEM;
+		}
+		/* both 64-bit and 32-bit use below 4GB address space */
+		return RES_TYPE_NONPREF_MEM;
+	}
+	printk(BIOS_ERR, "Invalid resource type 0x%llx\n", flags);
+	die("Invalida resource type");
+}
+
+static bool need_assignment(uint64_t flags)
+{
+	if (flags & (IORESOURCE_STORED | IORESOURCE_RESERVE | IORESOURCE_FIXED |
+		IORESOURCE_ASSIGNED))
+		return false;
+	else
+		return true;
+}
+
+static uint64_t get_resource_base(STACK_RES *stack, ResType res_type)
+{
+	if (res_type == RES_TYPE_IO) {
+		assert(stack->PciResourceIoBase <= stack->PciResourceIoLimit);
+		return stack->PciResourceIoBase;
+	}
+	if (res_type == RES_TYPE_NONPREF_MEM) {
+		assert(stack->PciResourceMem32Base <= stack->PciResourceMem32Limit);
+		return stack->PciResourceMem32Base;
+	}
+	assert(stack->PciResourceMem64Base <= stack->PciResourceMem64Limit);
+	return stack->PciResourceMem64Base;
+}
+
+static void set_resource_base(STACK_RES *stack, ResType res_type, uint64_t base)
+{
+	if (res_type == RES_TYPE_IO) {
+		assert(base <= (stack->PciResourceIoLimit + 1));
+		stack->PciResourceIoBase = base;
+	} else if (res_type == RES_TYPE_NONPREF_MEM) {
+		assert(base <= (stack->PciResourceMem32Limit + 1));
+		stack->PciResourceMem32Base = base;
+	} else {
+		assert(base <= (stack->PciResourceMem64Limit + 1));
+		stack->PciResourceMem64Base = base;
+	}
+}
+
+static void assign_stack_resources(struct iiostack_resource *stack_list,
+	struct device *dev, struct resource *bridge);
+
+static void xeonsp_cpx_pci_domain_scan_bus(struct device *dev)
+{
+	DEV_FUNC_ENTER(dev);
+	struct bus *link = dev->link_list;
+
+	printk(BIOS_SPEW, "%s:%s scanning buses under device %s\n",
+		__FILE__, __func__, dev_path(dev));
+	while (link != NULL) {
+		if (link->secondary == 0)  { // scan only PSTACK buses
+			struct device *d;
+			for (d = link->children; d; d = d->sibling)
+				pci_probe_dev(d, link, d->path.pci.devfn);
+			scan_bridges(link);
+		} else {
+			pci_scan_bus(link, PCI_DEVFN(0, 0), 0xff);
+		}
+		link = link->next;
+	}
+	DEV_FUNC_EXIT(dev);
+}
+
+static void xeonsp_pci_dev_iterator(struct bus *bus,
+		void (*dev_iterator)(struct device *, void *),
+		void (*res_iterator)(struct device *, struct resource *, void *),
+		void *data)
+{
+	struct device *curdev;
+	struct resource *res;
+
+	/* Walk through all devices and find which resources they need. */
+	for (curdev = bus->children; curdev; curdev = curdev->sibling) {
+		struct bus *link;
+
+		if (!curdev->enabled)
+			continue;
+
+		if (!curdev->ops || !curdev->ops->read_resources) {
+			if (curdev->path.type != DEVICE_PATH_APIC)
+				printk(BIOS_ERR, "%s missing read_resources\n",
+					dev_path(curdev));
+			continue;
+		}
+
+		if (dev_iterator)
+			dev_iterator(curdev, data);
+
+		if (res_iterator) {
+			for (res = curdev->resource_list; res; res = res->next)
+				res_iterator(curdev, res, data);
+		}
+
+		/* Read in the resources behind the current device's links. */
+		for (link = curdev->link_list; link; link = link->next)
+			xeonsp_pci_dev_iterator(link, dev_iterator, res_iterator, data);
+	}
+}
+
+static void xeonsp_pci_dev_read_resources(struct device *dev, void *data)
+{
+	post_log_path(dev);
+	dev->ops->read_resources(dev);
+}
+
+static void xeonsp_pci_dev_dummy_func(struct device *dev)
+{
+}
+
+static void xeonsp_reset_pci_op(struct device *dev, void *data)
+{
+	if (dev->ops)
+		dev->ops->read_resources = xeonsp_pci_dev_dummy_func;
+}
+
+static STACK_RES *find_stack_for_bus(struct iiostack_resource *info, uint8_t bus)
+{
+	for (int i = 0; i < info->no_of_stacks; ++i) {
+		if (bus >= info->res[i].BusBase && bus <= info->res[i].BusLimit)
+			return &info->res[i];
+	}
+	return NULL;
+}
+
+static void add_res_to_stack(struct stack_dev_resource **root,
+	struct device *dev, struct resource *res)
+{
+	struct stack_dev_resource *cur = *root;
+	while (cur) {
+		if (cur->align == res->align || cur->next == NULL) /* equal or last record */
+			break;
+		else if (cur->align > res->align) {
+			if (cur->next->align < res->align) /* need to insert new record here */
+				break;
+			cur = cur->next;
+		} else {
+			break;
+		}
+	}
+
+	struct stack_dev_resource *nr;
+	if (!cur || cur->align != res->align) { /* need to add new record */
+		nr = malloc(sizeof(struct stack_dev_resource));
+		if (nr == 0)
+			die("assign_resource_to_stack(): out of memory.\n");
+		memset(nr, 0, sizeof(struct stack_dev_resource));
+		nr->align = res->align;
+		if (!cur) {
+			*root = nr; /* head node */
+		} else if (cur->align > nr->align) {
+			if (cur->next == NULL) {
+				cur->next = nr;
+			} else {
+				nr->next = cur->next;
+				cur->next = nr;
+			}
+		} else { /* insert in the beginning */
+			nr->next = cur;
+			*root = nr;
+		}
+	} else {
+		nr = cur;
+	}
+
+	assert(nr != NULL && nr->align == res->align);
+
+	struct pci_resource *npr = malloc(sizeof(struct pci_resource));
+	if (npr == NULL)
+		die("%s: out of memory.\n", __func__);
+	npr->res = res;
+	npr->dev = dev;
+	npr->next = NULL;
+
+	if (nr->children == NULL) {
+		nr->children = npr;
+	} else {
+		struct pci_resource *pr = nr->children;
+		while (pr->next != NULL)
+			pr = pr->next;
+		pr->next = npr;
+	}
+}
+
+static void reserve_dev_resources(STACK_RES *stack, ResType res_type,
+	struct stack_dev_resource *res_root, struct resource *bridge)
+{
+	uint8_t align;
+	uint64_t orig_base, base;
+
+	orig_base = get_resource_base(stack, res_type);
+
+	align = 0;
+	base = orig_base;
+	int first = 1;
+	while (res_root) { /* loop through all devices grouped by alignment requirements */
+		struct pci_resource *pr = res_root->children;
+		while (pr) {
+			if (first) {
+				if (bridge) { /* takes highest alignment */
+					if (bridge->align < pr->res->align)
+						bridge->align = pr->res->align;
+					orig_base = ALIGN_UP(orig_base, 1 << bridge->align);
+				} else {
+					orig_base = ALIGN_UP(orig_base, 1 << pr->res->align);
+				}
+				base = orig_base;
+
+				if (bridge)
+					bridge->base = base;
+				pr->res->base = base;
+				first = 0;
+			} else {
+				pr->res->base = ALIGN_UP(base, 1 << pr->res->align);
+			}
+			pr->res->limit = pr->res->base + pr->res->size - 1;
+			base = pr->res->limit + 1;
+			pr->res->flags |= (IORESOURCE_ASSIGNED);
+			pr = pr->next;
+		}
+		res_root = res_root->next;
+	}
+
+	if (bridge) {
+		/* this bridge doesn't have any resources, will set it to default window */
+		if (first) {
+			orig_base = ALIGN_UP(orig_base, 1 << bridge->align);
+			bridge->base = orig_base;
+			base = orig_base + (1ULL << bridge->gran);
+		}
+
+		bridge->size = ALIGN_UP(base, 1 << bridge->align) - bridge->base;
+
+		bridge->limit = bridge->base + bridge->size - 1;
+		bridge->flags |= (IORESOURCE_ASSIGNED);
+		base = bridge->limit + 1;
+	}
+
+	set_resource_base(stack, res_type, base);
+}
+
+static void reclaim_resource_mem(struct stack_dev_resource *res_root)
+{
+	while (res_root) { /* loop through all devices grouped by alignment requirements */
+		/* free pci_resource */
+		struct pci_resource *pr = res_root->children;
+		while (pr) {
+			struct pci_resource *dpr = pr;
+			pr = pr->next;
+			free(dpr);
+		}
+
+		/* free stack_dev_resource */
+		struct stack_dev_resource *ddr = res_root;
+		res_root = res_root->next;
+		free(ddr);
+	}
+}
+
+static void assign_bridge_resources(struct iiostack_resource *stack_list,
+	struct device *dev, struct resource *bridge)
+{
+	struct resource *res;
+	if (!dev->enabled)
+		return;
+
+	for (res = dev->resource_list; res; res = res->next) {
+		if (!(res->flags & IORESOURCE_BRIDGE) ||
+		    (bridge && (get_res_type(bridge->flags) != get_res_type(res->flags))))
+			continue;
+
+		assign_stack_resources(stack_list, dev, res);
+
+		if (!bridge)
+			continue;
+
+		/* for 1st time update, overlading IORESOURCE_ASSIGNED */
+		if (!(bridge->flags & IORESOURCE_ASSIGNED)) {
+			bridge->base = res->base;
+			bridge->limit = res->limit;
+			bridge->flags |= (IORESOURCE_ASSIGNED);
+		} else {
+			/* update bridge range from child bridge range */
+			if (res->base < bridge->base)
+				bridge->base = res->base;
+			if (res->limit > bridge->limit)
+				bridge->limit = res->limit;
+		}
+		bridge->size = (bridge->limit - bridge->base + 1);
+	}
+}
+
+static void assign_stack_resources(struct iiostack_resource *stack_list,
+	struct device *dev, struct resource *bridge)
+{
+	struct bus *bus;
+
+	/* Read in the resources behind the current device's links. */
+	for (bus = dev->link_list; bus; bus = bus->next) {
+		struct device *curdev;
+		STACK_RES *stack;
+
+		/* get IIO stack for this bus */
+		stack = find_stack_for_bus(stack_list, bus->secondary);
+		assert(stack != NULL);
+
+		/* Assign resources to bridge */
+		for (curdev = bus->children; curdev; curdev = curdev->sibling)
+			assign_bridge_resources(stack_list, curdev, bridge);
+
+		/* Pick non-bridged resources for resource allocation for each resource type */
+		ResType res_types[MAX_RES_TYPES] = {
+			RES_TYPE_IO,
+			RES_TYPE_NONPREF_MEM,
+			RES_TYPE_PREF_MEM
+		};
+
+		uint8_t no_res_types = MAX_RES_TYPES;
+
+		/* if it is a bridge, only process matching brigge resource type */
+		if (bridge) {
+			res_types[0] = get_res_type(bridge->flags);
+			no_res_types = 1;
+		}
+
+		printk(BIOS_DEBUG, "%s:%d no_res_types: %d\n", __func__, __LINE__,
+			no_res_types);
+
+		/* Process each resource type */
+		for (int rt = 0; rt < no_res_types; ++rt) {
+			struct stack_dev_resource *res_root = NULL;
+			printk(BIOS_DEBUG, "%s:%d rt: %d\n", __func__, __LINE__, rt);
+			for (curdev = bus->children; curdev; curdev = curdev->sibling) {
+				struct resource *res;
+				printk(BIOS_DEBUG, "%s:%d dev: %s\n",
+					__func__, __LINE__, dev_path(curdev));
+				if (!curdev->enabled)
+					continue;
+
+				for (res = curdev->resource_list; res; res = res->next) {
+					printk(BIOS_DEBUG, "%s:%d dev: %s, flags: 0x%lx\n",
+						__func__, __LINE__,
+						dev_path(curdev), res->flags);
+					if (res->size == 0                            ||
+					    get_res_type(res->flags) != res_types[rt] ||
+					    (res->flags & IORESOURCE_BRIDGE)          ||
+					    !need_assignment(res->flags))
+						continue;
+					else
+						add_res_to_stack(&res_root, curdev, res);
+				}
+			}
+
+			/* Allocate resources and update bridge range */
+			if (res_root || (bridge && !(bridge->flags & IORESOURCE_ASSIGNED))) {
+				reserve_dev_resources(stack, res_types[rt], res_root, bridge);
+				reclaim_resource_mem(res_root);
+			}
+		}
+	}
+}
+
+static void xeonsp_pci_domain_read_resources(struct device *dev)
+{
+	struct bus *link;
+
+	DEV_FUNC_ENTER(dev);
+
+	pci_domain_read_resources(dev);
+
+	/*
+	 * Walk through all devices in this domain and read resources.
+	 * Since there is no callback when read resource operation is
+	 * complete for all devices, domain read resource function initiates
+	 * read resources for all devices and swaps read resource operation
+	 * with dummy function to avoid warning.
+	 */
+	for (link = dev->link_list; link; link = link->next)
+		xeonsp_pci_dev_iterator(link, xeonsp_pci_dev_read_resources, NULL, NULL);
+
+	for (link = dev->link_list; link; link = link->next)
+		xeonsp_pci_dev_iterator(link, xeonsp_reset_pci_op, NULL, NULL);
+
+	struct iiostack_resource stack_info = {0};
+	uint8_t pci64bit_alloc_flag = get_iiostack_info(&stack_info);
+	if (!pci64bit_alloc_flag) {
+		/*
+		 * Split 32 bit address space between prefetchable and
+		 * non-prefetchable windows
+		 */
+		for (int s = 0; s < stack_info.no_of_stacks; ++s) {
+			STACK_RES *res = &stack_info.res[s];
+			uint64_t length = (res->PciResourceMem32Limit -
+				res->PciResourceMem32Base + 1)/2;
+			res->PciResourceMem64Limit = res->PciResourceMem32Limit;
+			res->PciResourceMem32Limit = (res->PciResourceMem32Base + length - 1);
+			res->PciResourceMem64Base = res->PciResourceMem32Limit + 1;
+		}
+	}
+
+
+	/* assign resources */
+	assign_stack_resources(&stack_info, dev, NULL);
+
+	DEV_FUNC_EXIT(dev);
+}
+
+static void reset_resource_to_unassigned(struct device *dev, struct resource *res, void *data)
+{
+	if ((res->flags & (IORESOURCE_IO | IORESOURCE_MEM)) &&
+		!(res->flags & (IORESOURCE_FIXED | IORESOURCE_RESERVE))) {
+		res->flags &= ~IORESOURCE_ASSIGNED;
+	}
+}
+
+static void xeonsp_cpx_pci_domain_set_resources(struct device *dev)
+{
+	DEV_FUNC_ENTER(dev);
+
+	print_resource_tree(dev, BIOS_SPEW, "Before xeonsp pci domain set resource");
+
+	/* reset bus 0 dev resource assignment - need to change them to FSP IIOStack window */
+	xeonsp_pci_dev_iterator(dev->link_list, NULL, reset_resource_to_unassigned, NULL);
+
+	/* update dev resources based on IIOStack IO/Mem32/Mem64 windows */
+	xeonsp_pci_domain_read_resources(dev);
+
+	struct bus *link = dev->link_list;
+	while (link != NULL) {
+		assign_resources(link);
+		link = link->next;
+	}
+
+	print_resource_tree(dev, BIOS_SPEW, "After xeonsp pci domain set resource");
+
+	DEV_FUNC_EXIT(dev);
+}
+
 void platform_fsp_silicon_init_params_cb(FSPS_UPD *silupd)
 {
    /* not implemented yet */
@@ -20,8 +494,8 @@

static struct device_operations pci_domain_ops = {
    .read_resources = &pci_domain_read_resources,
-	.set_resources = &pci_domain_set_resources,
-	.scan_bus = &pci_domain_scan_bus,
+	.set_resources = &xeonsp_cpx_pci_domain_set_resources,
+	.scan_bus = &xeonsp_cpx_pci_domain_scan_bus,
 };

static struct device_operations cpu_bus_ops = {
@@ -30,14 +504,43 @@
    .init = cpx_init_cpus,
 };

-static void chip_enable_dev(struct device *dev)
+/* Attach IIO stack bus numbers with dummy device to PCI DOMAIN 0000 device */
+static void attach_iio_stacks(struct device *dev)
 {
-	/* Set the operations if it is a special bus type */
-	if (dev->path.type == DEVICE_PATH_DOMAIN) {
-		dev->ops = &pci_domain_ops;
-	} else if (dev->path.type == DEVICE_PATH_CPU_CLUSTER) {
-		dev->ops = &cpu_bus_ops;
+	struct bus *iiostack_bus;
+	struct iiostack_resource stack_info = {0};
+
+	DEV_FUNC_ENTER(dev);
+
+	get_iiostack_info(&stack_info);
+	for (int s = 0; s < stack_info.no_of_stacks; ++s) {
+		/* only non zero bus no. needs to be enumerated */
+		if (stack_info.res[s].BusBase == 0)
+			continue;
+
+		iiostack_bus = malloc(sizeof(struct bus));
+		if (iiostack_bus == NULL)
+			die("%s: out of memory.\n", __func__);
+		memset(iiostack_bus, 0, sizeof(*iiostack_bus));
+		memcpy(iiostack_bus, dev->bus, sizeof(*iiostack_bus));
+		iiostack_bus->secondary = stack_info.res[s].BusBase;
+		iiostack_bus->subordinate = stack_info.res[s].BusBase;
+		iiostack_bus->dev = NULL;
+		iiostack_bus->children = NULL;
+		iiostack_bus->next = NULL;
+		iiostack_bus->link_num = 1;
+
+		if (dev->link_list == NULL) {
+			dev->link_list = iiostack_bus;
+		} else {
+			struct bus *nlink = dev->link_list;
+			while (nlink->next != NULL)
+				nlink = nlink->next;
+			nlink->next = iiostack_bus;
+		}
    }
+
+	DEV_FUNC_EXIT(dev);
 }

static void pch_enable_ioapic(const struct device *dev)
@@ -65,6 +568,17 @@
    .set_subsystem = pci_dev_set_subsystem,
 };

+static void chip_enable_dev(struct device *dev)
+{
+	/* Set the operations if it is a special bus type */
+	if (dev->path.type == DEVICE_PATH_DOMAIN) {
+		dev->ops = &pci_domain_ops;
+		attach_iio_stacks(dev);
+	} else if (dev->path.type == DEVICE_PATH_CPU_CLUSTER) {
+		dev->ops = &cpu_bus_ops;
+	}
+}
+
 static void chip_final(void *data)
 {
    p2sb_hide();
@@ -83,5 +597,5 @@
    CHIP_NAME("Intel Cooperlake-SP")
    .enable_dev = chip_enable_dev,
    .init = chip_init,
-	.final = chip_final
+	.final = chip_final,
 };
diff --git a/src/soc/intel/xeon_sp/cpx/chip.h b/src/soc/intel/xeon_sp/cpx/chip.h
index 87dd2b3..6bf7272 100644
--- a/src/soc/intel/xeon_sp/cpx/chip.h
+++ b/src/soc/intel/xeon_sp/cpx/chip.h
@@ -3,13 +3,65 @@
 #ifndef _SOC_CHIP_H_
 #define _SOC_CHIP_H_

-#include <stdint.h>
 #include <intelblocks/cfg.h>
+#include <soc/irq.h>
+#include <stdint.h>

struct soc_intel_xeon_sp_cpx_config {
    /* Common struct containing soc config data required by common code */
    struct soc_intel_common_config common_soc_config;

+	/**
+	 * Interrupt Routing configuration
+	 * If bit7 is 1, the interrupt is disabled.
+	 */
+	uint8_t pirqa_routing;
+	uint8_t pirqb_routing;
+	uint8_t pirqc_routing;
+	uint8_t pirqd_routing;
+	uint8_t pirqe_routing;
+	uint8_t pirqf_routing;
+	uint8_t pirqg_routing;
+	uint8_t pirqh_routing;
+
+	/**
+	 * Device Interrupt Routing configuration
+	 * Interrupt Pin x Route.
+	 * 0h = PIRQA#
+	 * 1h = PIRQB#
+	 * 2h = PIRQC#
+	 * 3h = PIRQD#
+	 * 4h = PIRQE#
+	 * 5h = PIRQF#
+	 * 6h = PIRQG#
+	 * 7h = PIRQH#
+	 */
+	uint16_t ir00_routing;
+	uint16_t ir01_routing;
+	uint16_t ir02_routing;
+	uint16_t ir03_routing;
+	uint16_t ir04_routing;
+
+	/**
+	* Device Interrupt Polarity Control
+	* ipc0 - IRQ-00-31 - 1: Active low to IOAPIC, 0: Active high to IOAPIC
+	* ipc1 - IRQ-32-63 - 1: Active low to IOAPIC, 0: Active high to IOAPIC
+	* ipc2 - IRQ-64-95 - 1: Active low to IOAPIC, 0: Active high to IOAPIC
+	* ipc3 - IRQ-96-119 - 1: Active low to IOAPIC, 0: Active high to IOAPIC
+	*/
+	uint32_t ipc0;
+	uint32_t ipc1;
+	uint32_t ipc2;
+	uint32_t ipc3;
+
+	uint64_t turbo_ratio_limit;
+	uint64_t turbo_ratio_limit_cores;
+
+	uint32_t pstate_req_ratio;
+
+	uint32_t coherency_support;
+	uint32_t ats_support;
+
    /* Generic IO decode ranges */
    uint32_t gen1_dec;
    uint32_t gen2_dec;
diff --git a/src/soc/intel/xeon_sp/cpx/include/soc/irq.h b/src/soc/intel/xeon_sp/cpx/include/soc/irq.h
index 71e0584..efd5057 100644
--- a/src/soc/intel/xeon_sp/cpx/include/soc/irq.h
+++ b/src/soc/intel/xeon_sp/cpx/include/soc/irq.h
@@ -1,3 +1,9 @@
 /* SPDX-License-Identifier: GPL-2.0-only */

-/* nothing here, please come back later */
+#ifndef _SOC_IRQ_H_
+#define _SOC_IRQ_H_
+
+#define PCH_IRQ10          10
+#define PCH_IRQ11          11
+
+#endif /* _SOC_IRQ_H_ */
diff --git a/src/soc/intel/xeon_sp/cpx/include/soc/soc_util.h b/src/soc/intel/xeon_sp/cpx/include/soc/soc_util.h
new file mode 100644
index 0000000..d8b038c
--- /dev/null
+++ b/src/soc/intel/xeon_sp/cpx/include/soc/soc_util.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _SOC_UTIL_H_
+#define _SOC_UTIL_H_
+
+#include <console/console.h>
+#include <hob_iiouds.h>
+#include <hob_memmap.h>
+#include <stdint.h>
+
+#define DEV_FUNC_ENTER(dev) \
+	printk(BIOS_SPEW, "%s:%s:%d: ENTER (dev: %s)\n", \
+		__FILE__, __func__, __LINE__, dev_path(dev))
+
+#define DEV_FUNC_EXIT(dev) \
+	printk(BIOS_SPEW, "%s:%s:%d: EXIT (dev: %s)\n", __FILE__, \
+		__func__, __LINE__, dev_path(dev))
+
+struct iiostack_resource {
+	uint8_t     no_of_stacks;
+	STACK_RES   res[MAX_SOCKET * MAX_LOGIC_IIO_STACK];
+};
+
+uint8_t get_iiostack_info(struct iiostack_resource *info);
+#endif /* _SOC_UTIL_H_ */
diff --git a/src/soc/intel/xeon_sp/cpx/soc_util.c b/src/soc/intel/xeon_sp/cpx/soc_util.c
new file mode 100644
index 0000000..8548615
--- /dev/null
+++ b/src/soc/intel/xeon_sp/cpx/soc_util.c
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <assert.h>
+#include <soc/soc_util.h>
+#include <stdlib.h>
+#include <string.h>
+
+uint8_t get_iiostack_info(struct iiostack_resource *info)
+{
+	size_t hob_size;
+	const uint8_t fsp_hob_iio_universal_data_guid[16] = FSP_HOB_IIO_UNIVERSAL_DATA_GUID;
+	const IIO_UDS *hob;
+
+	hob = fsp_find_extension_hob_by_guid(
+		fsp_hob_iio_universal_data_guid, &hob_size);
+	assert(hob != NULL && hob_size != 0);
+
+	// copy IIO Stack info from FSP HOB
+	info->no_of_stacks = 0;
+	for (int s = 0; s < hob->PlatformData.numofIIO; ++s) {
+		for (int x = 0; x < MAX_IIO_STACK; ++x) {
+			const STACK_RES *ri = &hob->PlatformData.IIO_resource[s].StackRes[x];
+			// TODO: do we have situation with only bux 0 and one stack?
+			if (ri->BusBase >= ri->BusLimit)
+				continue;
+			assert(info->no_of_stacks < (CONFIG_MAX_SOCKET * MAX_IIO_STACK));
+			memcpy(&info->res[info->no_of_stacks++], ri, sizeof(STACK_RES));
+		}
+	}
+
+	return hob->PlatformData.Pci64BitResourceAllocation;
+}
diff --git a/src/soc/intel/xeon_sp/include/soc/util.h b/src/soc/intel/xeon_sp/include/soc/util.h
index 24baca6..159efeb 100644
--- a/src/soc/intel/xeon_sp/include/soc/util.h
+++ b/src/soc/intel/xeon_sp/include/soc/util.h
@@ -4,6 +4,7 @@
 #define _XEON_SP_SOC_UTIL_H_

#include <console/console.h>
+#include <hob_iiouds.h>

void get_cpubusnos(uint32_t *bus0, uint32_t *bus1, uint32_t *bus2, uint32_t *bus3);
 void unlock_pam_regions(void);