soc/intel/xeon_sp: Redesign resource allocation

The xeon_sp code worked around the coreboot allocator rather than using
it. Now the allocator is able to deal with the multiple IIOs so this is
not necessary anymore.

Instead do the following:
- Parse the FSP HOB information about IIO into coreboot PCI domains
- Use existing scan_bus and read_resource
- Handle IOAT stacks with multiple domains in soc-specific code

TEST=intel/archercity CRB

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Signed-off-by: Nico Huber <nico.h@gmx.de>
Signed-off-by: Shuo Liu <shuo.liu@intel.com>
Change-Id: Idb29c24b71a18e2e092f9d4953d106e6ca0a5fe1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78327
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>

17 files changed, 269 insertions, 544 deletions

diff --git a/src/soc/intel/xeon_sp/Kconfig b/src/soc/intel/xeon_sp/Kconfig
index 1eee8694a3..09310300dc 100644
--- a/src/soc/intel/xeon_sp/Kconfig
+++ b/src/soc/intel/xeon_sp/Kconfig
@@ -107,4 +107,7 @@ config SOC_INTEL_XEON_RAS
 	select SOC_ACPI_HEST
 	select SOC_RAS_ELOG
 
+config HAVE_IOAT_DOMAINS
+	bool
+
 endif ## SOC_INTEL_XEON_SP
diff --git a/src/soc/intel/xeon_sp/acpi.c b/src/soc/intel/xeon_sp/acpi.c
index 519d6c7c76..61d51862f5 100644
--- a/src/soc/intel/xeon_sp/acpi.c
+++ b/src/soc/intel/xeon_sp/acpi.c
@@ -104,7 +104,7 @@ size_t soc_get_ioapic_info(const uintptr_t *ioapic_bases[])
 		for (int stack = 0; stack < MAX_IIO_STACK; ++stack) {
 			const STACK_RES *ri =
 				&hob->PlatformData.IIO_resource[socket].StackRes[stack];
-			if (!is_iio_stack_res(ri))
+			if (!stack_needs_resource_alloc(ri))
 				continue;
 			uint32_t ioapic_base = ri->IoApicBase;
 			assert(index < ARRAY_SIZE(xeonsp_ioapic_bases));
diff --git a/src/soc/intel/xeon_sp/chip_common.c b/src/soc/intel/xeon_sp/chip_common.c
index a9b1260646..c1b331bc66 100644
--- a/src/soc/intel/xeon_sp/chip_common.c
+++ b/src/soc/intel/xeon_sp/chip_common.c
@@ -9,548 +9,122 @@
 #include <soc/util.h>
 #include <stdlib.h>
 
-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
-} RES_TYPE;
-
-static RES_TYPE 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;
-	}
-	die("Invalid resource type 0x%llx\n", flags);
-}
-
-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, RES_TYPE 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, RES_TYPE res_type, uint64_t base)
+static const STACK_RES *domain_to_stack_res(const struct device *dev)
 {
-	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;
-	}
-}
+	assert(dev->path.type == DEVICE_PATH_DOMAIN);
+	const unsigned int dn = dev->path.domain.domain;
 
-static void assign_stack_resources(struct iiostack_resource *stack_list,
-	struct device *dev, struct resource *bridge);
-
-void xeonsp_pci_domain_scan_bus(struct device *dev)
-{
-	DEV_FUNC_ENTER(dev);
-	struct bus *link = dev->link_list;
+	const IIO_UDS *hob = get_iio_uds();
+	assert(hob != NULL);
 
-	printk(BIOS_SPEW, "%s:%s scanning buses under device %s\n",
-		__FILE__, __func__, dev_path(dev));
-	while (link) {
-		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);
+	return &hob->PlatformData.IIO_resource[dn / MAX_LOGIC_IIO_STACK].StackRes[dn % MAX_LOGIC_IIO_STACK];
 }
 
-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)
+void iio_pci_domain_read_resources(struct device *dev)
 {
-	struct device *curdev;
 	struct resource *res;
+	const STACK_RES *sr = domain_to_stack_res(dev);
 
-	/* 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) /* 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) {
-				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 && nr->align == res->align);
+	if (!sr)
+		return;
 
-	struct pci_resource *npr = malloc(sizeof(struct pci_resource));
-	if (!npr)
-		die("%s: out of memory.\n", __func__);
-	npr->res = res;
-	npr->dev = dev;
-	npr->next = NULL;
+	int index = 0;
 
-	if (!nr->children) {
-		nr->children = npr;
-	} else {
-		struct pci_resource *pr = nr->children;
-		while (pr->next)
-			pr = pr->next;
-		pr->next = npr;
+	if (dev->path.domain.domain == 0) {
+		/* The 0 - 0xfff IO range is not reported by the HOB but still gets decoded */
+		res = new_resource(dev, index++);
+		res->base = 0;
+		res->size = 0x1000;
+		res->limit = 0xfff;
+		res->flags = IORESOURCE_IO | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED;
 	}
-}
-
-static void reserve_dev_resources(STACK_RES *stack, RES_TYPE res_type,
-	struct stack_dev_resource *res_root, struct resource *bridge)
-{
-	uint64_t orig_base, base;
-
-	orig_base = get_resource_base(stack, res_type);
 
-	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 (sr->PciResourceIoBase < sr->PciResourceIoLimit) {
+		res = new_resource(dev, index++);
+		res->base = sr->PciResourceIoBase;
+		res->limit = sr->PciResourceIoLimit;
+		res->size = res->limit - res->base + 1;
+		res->flags = IORESOURCE_IO | IORESOURCE_ASSIGNED;
 	}
 
-	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;
+	if (sr->PciResourceMem32Base < sr->PciResourceMem32Limit) {
+		res = new_resource(dev, index++);
+		res->base = sr->PciResourceMem32Base;
+		res->limit = sr->PciResourceMem32Limit;
+		res->size = res->limit - res->base + 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED;
 	}
 
-	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);
+	if (sr->PciResourceMem64Base < sr->PciResourceMem64Limit) {
+		res = new_resource(dev, index++);
+		res->base = sr->PciResourceMem64Base;
+		res->limit = sr->PciResourceMem64Limit;
+		res->size = res->limit - res->base + 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED;
 	}
 }
 
-static void assign_bridge_resources(struct iiostack_resource *stack_list,
-	struct device *dev, struct resource *bridge)
+void iio_pci_domain_scan_bus(struct device *dev)
 {
-	struct resource *res;
-	if (!dev->enabled)
+	const STACK_RES *sr = domain_to_stack_res(dev);
+	if (!sr)
 		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);
+	if (!dev->link_list) {
+		dev->link_list = calloc(1, sizeof(struct bus));
+		if (!dev->link_list)
+			die("%s: out of memory.\n", __func__);
 	}
-}
-
-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);
-
-		/* 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 */
-		RES_TYPE res_types[MAX_RES_TYPES] = {
-			RES_TYPE_IO,
-			RES_TYPE_NONPREF_MEM,
-			RES_TYPE_PREF_MEM
-		};
 
-		uint8_t no_res_types = MAX_RES_TYPES;
+	struct bus *bus = dev->link_list;
+	bus->secondary = sr->BusBase;
+	bus->subordinate = sr->BusBase;
+	bus->max_subordinate = sr->BusLimit;
 
-		/* if it is a bridge, only process matching bridge 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);
-			}
-		}
-	}
+	printk(BIOS_SPEW, "Scanning IIO stack %d: busses %x-%x\n", dev->path.domain.domain,
+	       dev->link_list->secondary, dev->link_list->max_subordinate);
+	pci_host_bridge_scan_bus(dev);
 }
 
-static uint8_t is_pci64bit_alloc(void)
-{
 /*
- * For SPR-SP FSP which supports SOC_INTEL_PCIE_64BITS_ALLOC,
- * Pci64BitResourceAllocation field does not exist in IIO_UDS HOB.
+ * Used by IIO stacks for PCIe bridges. Those contain 1 PCI host bridges,
+ *  all the bus numbers on the IIO stack can be used for this bridge
  */
-#if CONFIG(SOC_INTEL_PCIE_64BIT_ALLOC)
-	return 1;
-#else
-	const IIO_UDS *hob = get_iio_uds();
-	return hob->PlatformData.Pci64BitResourceAllocation;
-#endif
-}
-
-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};
-	get_iiostack_info(&stack_info);
-	if (!is_pci64bit_alloc()) {
-		/*
-		 * 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;
-	}
-}
-
-void xeonsp_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) {
-		assign_resources(link);
-		link = link->next;
-	}
-
-	print_resource_tree(dev, BIOS_SPEW, "After xeonsp pci domain set resource");
-
-	DEV_FUNC_EXIT(dev);
-}
+static struct device_operations iio_pcie_domain_ops = {
+	.read_resources = iio_pci_domain_read_resources,
+	.set_resources = pci_domain_set_resources,
+	.scan_bus = iio_pci_domain_scan_bus,
+};
 
-/* Attach IIO stack bus numbers with dummy device to PCI DOMAIN 0000 device */
+/* Attach IIO stack as domains */
 void attach_iio_stacks(struct device *dev)
 {
-	struct device dummy;
-	struct iiostack_resource stack_info = {0};
-
-	DEV_FUNC_ENTER(dev);
-
-	get_iiostack_info(&stack_info);
+	const IIO_UDS *hob = get_iio_uds();
+	if (!hob)
+		return;
 
-	for (int s = 0; s < stack_info.no_of_stacks; ++s) {
-		STACK_RES *sr = &stack_info.res[s];
-		/* only non zero bus no. needs to be enumerated */
-		if (sr->BusBase == 0) {
-			/* Update BUS 0 BusLimit */
-			dev->link_list->max_subordinate = sr->BusLimit;
-			continue;
-		}
+	for (int s = 0; s < hob->PlatformData.numofIIO; ++s) {
+		for (int x = 0; x < MAX_LOGIC_IIO_STACK; ++x) {
+			if (s == 0 && x == 0)
+				continue;
 
-		for (int b = sr->BusBase; b <= sr->BusLimit; ++b) {
-			struct bus tmp_bus;
-			memset(&tmp_bus, 0, sizeof(tmp_bus));
-			memcpy(&tmp_bus, dev->bus, sizeof(tmp_bus));
-			tmp_bus.secondary = b;
-			tmp_bus.subordinate = b;
-			tmp_bus.max_subordinate = sr->BusLimit;
-			tmp_bus.dev = NULL;
-			tmp_bus.children = NULL;
-			tmp_bus.next = NULL;
-			tmp_bus.link_num = 1;
+			const STACK_RES *ri = &hob->PlatformData.IIO_resource[s].StackRes[x];
+			if (!stack_needs_resource_alloc(ri))
+				continue;
 
-			dummy.bus = &tmp_bus;
-			dummy.path.type = DEVICE_PATH_PCI;
-			dummy.path.pci.devfn = 0;
-			uint32_t id = pci_read_config32(&dummy, PCI_VENDOR_ID);
-			if (id == 0xffffffff) {
-				printk(BIOS_DEBUG, "IIO Stack device %s not visible\n",
-					dev_path(&dummy));
+			if (!is_pcie_iio_stack_res(ri)) {
+				if (CONFIG(HAVE_IOAT_DOMAINS))
+					soc_create_ioat_domains(dev->bus, ri);
 				continue;
 			}
 
-			printk(BIOS_DEBUG, "%s Attaching IIO Bus %s\n", __func__,
-				dev_path(&dummy));
-			printk(BIOS_DEBUG, "    %s attach secondary: 0x%x, subordinate: 0x%x, dev: %s\n",
-				__func__, tmp_bus.secondary,
-				tmp_bus.subordinate, dev_path(&dummy));
-
-			struct bus *iiostack_bus = malloc(sizeof(struct bus));
-			if (iiostack_bus == NULL)
+			struct device_path path;
+			path.type = DEVICE_PATH_DOMAIN;
+			path.domain.domain = s * MAX_LOGIC_IIO_STACK + x;
+			struct device *iio_domain = alloc_dev(dev->bus, &path);
+			if (iio_domain == NULL)
 				die("%s: out of memory.\n", __func__);
-			memcpy(iiostack_bus, &tmp_bus, sizeof(*iiostack_bus));
-
-			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;
-			}
+			iio_domain->ops = &iio_pcie_domain_ops;
 		}
 	}
-
-	DEV_FUNC_EXIT(dev);
 }
diff --git a/src/soc/intel/xeon_sp/cpx/chip.c b/src/soc/intel/xeon_sp/cpx/chip.c
index dd9c113491..39a7ebaae2 100644
--- a/src/soc/intel/xeon_sp/cpx/chip.c
+++ b/src/soc/intel/xeon_sp/cpx/chip.c
@@ -36,9 +36,9 @@ const char *soc_acpi_name(const struct device *dev)
 #endif
 
 static struct device_operations pci_domain_ops = {
-	.read_resources = &pci_domain_read_resources,
-	.set_resources = &xeonsp_pci_domain_set_resources,
-	.scan_bus = &xeonsp_pci_domain_scan_bus,
+	.read_resources = iio_pci_domain_read_resources,
+	.set_resources = pci_domain_set_resources,
+	.scan_bus = iio_pci_domain_scan_bus,
 #if CONFIG(HAVE_ACPI_TABLES)
 	.write_acpi_tables  = &northbridge_write_acpi_tables,
 	.acpi_name        = soc_acpi_name
diff --git a/src/soc/intel/xeon_sp/cpx/soc_util.c b/src/soc/intel/xeon_sp/cpx/soc_util.c
index 64efb612ca..e277752e5c 100644
--- a/src/soc/intel/xeon_sp/cpx/soc_util.c
+++ b/src/soc/intel/xeon_sp/cpx/soc_util.c
@@ -25,11 +25,16 @@ const struct SystemMemoryMapHob *get_system_memory_map(void)
 	return *memmap_addr;
 }
 
-bool is_iio_stack_res(const STACK_RES *res)
+bool stack_needs_resource_alloc(const STACK_RES *res)
 {
 	return res->Personality == TYPE_UBOX_IIO;
 }
 
+bool is_pcie_iio_stack_res(const STACK_RES *res)
+{
+	return stack_needs_resource_alloc(res);
+}
+
 uint8_t get_stack_busno(const uint8_t stack)
 {
 	if (stack >= MAX_IIO_STACK) {
diff --git a/src/soc/intel/xeon_sp/include/soc/chip_common.h b/src/soc/intel/xeon_sp/include/soc/chip_common.h
index 339da07e4a..ac8ba9e422 100644
--- a/src/soc/intel/xeon_sp/include/soc/chip_common.h
+++ b/src/soc/intel/xeon_sp/include/soc/chip_common.h
@@ -3,8 +3,12 @@
 #ifndef _CHIP_COMMON_H_
 #define _CHIP_COMMON_H_
 
-void xeonsp_pci_domain_set_resources(struct device *dev);
-void xeonsp_pci_domain_scan_bus(struct device *dev);
+#include <hob_iiouds.h>
+
+void iio_pci_domain_read_resources(struct device *dev);
+void iio_pci_domain_scan_bus(struct device *dev);
 void attach_iio_stacks(struct device *dev);
 
+void soc_create_ioat_domains(struct bus *bus, const STACK_RES *sr);
+
 #endif /* _CHIP_COMMON_H_ */
diff --git a/src/soc/intel/xeon_sp/include/soc/util.h b/src/soc/intel/xeon_sp/include/soc/util.h
index 8e80c64d14..a03c8e8404 100644
--- a/src/soc/intel/xeon_sp/include/soc/util.h
+++ b/src/soc/intel/xeon_sp/include/soc/util.h
@@ -23,7 +23,8 @@ struct iiostack_resource {
 };
 
 void get_iiostack_info(struct iiostack_resource *info);
-bool is_iio_stack_res(const STACK_RES *res);
+bool stack_needs_resource_alloc(const STACK_RES *res);
+bool is_pcie_iio_stack_res(const STACK_RES *res);
 void bios_done_msr(void *unused);
 
 #endif
diff --git a/src/soc/intel/xeon_sp/memmap.c b/src/soc/intel/xeon_sp/memmap.c
index 8562eb1918..e73143fc78 100644
--- a/src/soc/intel/xeon_sp/memmap.c
+++ b/src/soc/intel/xeon_sp/memmap.c
@@ -74,7 +74,7 @@ union dpr_register txt_get_chipset_dpr(void)
 		for (int stack = 0; stack < MAX_IIO_STACK; ++stack) {
 			const STACK_RES *ri =
 				&hob->PlatformData.IIO_resource[socket].StackRes[stack];
-			if (!is_iio_stack_res(ri))
+			if (!stack_needs_resource_alloc(ri))
 				continue;
 			uint8_t bus = ri->BusBase;
 			dev = VTD_DEV(bus);
diff --git a/src/soc/intel/xeon_sp/skx/chip.c b/src/soc/intel/xeon_sp/skx/chip.c
index a113d5a186..b468842e92 100644
--- a/src/soc/intel/xeon_sp/skx/chip.c
+++ b/src/soc/intel/xeon_sp/skx/chip.c
@@ -23,9 +23,9 @@ const char *soc_acpi_name(const struct device *dev)
 #endif
 
 static struct device_operations pci_domain_ops = {
-	.read_resources = &pci_domain_read_resources,
-	.set_resources = &xeonsp_pci_domain_set_resources,
-	.scan_bus = &xeonsp_pci_domain_scan_bus,
+	.read_resources = iio_pci_domain_read_resources,
+	.set_resources = pci_domain_set_resources,
+	.scan_bus = iio_pci_domain_scan_bus,
 #if CONFIG(HAVE_ACPI_TABLES)
 	.write_acpi_tables  = &northbridge_write_acpi_tables,
 	.acpi_name        = soc_acpi_name
diff --git a/src/soc/intel/xeon_sp/skx/soc_util.c b/src/soc/intel/xeon_sp/skx/soc_util.c
index b501a3e04f..d61d07489f 100644
--- a/src/soc/intel/xeon_sp/skx/soc_util.c
+++ b/src/soc/intel/xeon_sp/skx/soc_util.c
@@ -54,12 +54,17 @@ const struct SystemMemoryMapHob *get_system_memory_map(void)
 	return memmap_addr;
 }
 
-bool is_iio_stack_res(const STACK_RES *res)
+bool stack_needs_resource_alloc(const STACK_RES *res)
 {
 	// TODO: do we have situation with only bux 0 and one stack?
 	return res->BusBase < res->BusLimit;
 }
 
+bool is_pcie_iio_stack_res(const STACK_RES *res)
+{
+	return stack_needs_resource_alloc(res);
+}
+
 uint8_t get_stack_busno(const uint8_t stack)
 {
 	if (stack >= MAX_IIO_STACK) {
diff --git a/src/soc/intel/xeon_sp/spr/Kconfig b/src/soc/intel/xeon_sp/spr/Kconfig
index 396072448d..5a21f47b43 100644
--- a/src/soc/intel/xeon_sp/spr/Kconfig
+++ b/src/soc/intel/xeon_sp/spr/Kconfig
@@ -12,6 +12,7 @@ config SOC_INTEL_SAPPHIRERAPIDS_SP
 	select PLATFORM_USES_FSP2_3
 	select SOC_INTEL_CSE_SERVER_SKU
 	select XEON_SP_COMMON_BASE
+	select HAVE_IOAT_DOMAINS
 	help
 	  Intel Sapphire Rapids-SP support
 
diff --git a/src/soc/intel/xeon_sp/spr/Makefile.inc b/src/soc/intel/xeon_sp/spr/Makefile.inc
index 3e4f9cd329..7a0d9586c5 100644
--- a/src/soc/intel/xeon_sp/spr/Makefile.inc
+++ b/src/soc/intel/xeon_sp/spr/Makefile.inc
@@ -13,7 +13,7 @@ romstage-$(CONFIG_DISPLAY_HOBS) += hob_display.c
 romstage-$(CONFIG_DISPLAY_UPD_DATA) += upd_display.c
 
 ramstage-y += chip.c cpu.c soc_util.c ramstage.c soc_acpi.c xhci.c numa.c reset.c
-ramstage-y += crashlog.c
+ramstage-y += crashlog.c ioat.c
 ramstage-$(CONFIG_DISPLAY_HOBS) += hob_display.c
 ramstage-$(CONFIG_DISPLAY_UPD_DATA) += upd_display.c
 smm-$(CONFIG_HAVE_SMI_HANDLER) += soc_smihandler_util.c
diff --git a/src/soc/intel/xeon_sp/spr/chip.c b/src/soc/intel/xeon_sp/spr/chip.c
index f9c43dbe9a..3b3c65e4a0 100644
--- a/src/soc/intel/xeon_sp/spr/chip.c
+++ b/src/soc/intel/xeon_sp/spr/chip.c
@@ -47,9 +47,9 @@ const char *soc_acpi_name(const struct device *dev)
 #endif
 
 static struct device_operations pci_domain_ops = {
-	.read_resources = &pci_domain_read_resources,
-	.set_resources = &xeonsp_pci_domain_set_resources,
-	.scan_bus = &xeonsp_pci_domain_scan_bus,
+	.read_resources = iio_pci_domain_read_resources,
+	.set_resources = pci_domain_set_resources,
+	.scan_bus = iio_pci_domain_scan_bus,
 #if CONFIG(HAVE_ACPI_TABLES)
 	.write_acpi_tables = &northbridge_write_acpi_tables,
 	.acpi_name = soc_acpi_name
diff --git a/src/soc/intel/xeon_sp/spr/ioat.c b/src/soc/intel/xeon_sp/spr/ioat.c
new file mode 100644
index 0000000000..f10863a607
--- /dev/null
+++ b/src/soc/intel/xeon_sp/spr/ioat.c
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <stdbool.h>
+
+#include <console/console.h>
+#include <device/device.h>
+#include <device/resource.h>
+
+#include <defs_iio.h>
+#include <hob_iiouds.h>
+#include <IioPcieConfigUpd.h>
+
+#include <soc/chip_common.h>
+
+/*
+ * Used for IIO stacks for accelerators and other functionality (IOAT).
+ * Those have only integrated PCI endpoints (no bridges) behind the host bridge.
+ */
+
+static struct device_operations ioat_domain_ops = {
+	.read_resources = noop_read_resources,
+	.set_resources = pci_domain_set_resources,
+	.scan_bus = pci_host_bridge_scan_bus,
+};
+
+static void create_ioat_domain(struct bus *const upstream, const unsigned int domain_base,
+				const unsigned int bus_base, const unsigned int bus_limit,
+				const resource_t mem32_base, const resource_t mem32_limit,
+				const resource_t mem64_base, const resource_t mem64_limit)
+{
+	struct device_path path = {
+		.type = DEVICE_PATH_DOMAIN,
+		.domain = {
+			.domain = domain_base + bus_base,
+		},
+	};
+	struct device *const domain = alloc_dev(upstream, &path);
+	if (!domain)
+		die("%s: out of memory.\n", __func__);
+
+	domain->ops = &ioat_domain_ops;
+
+	domain->link_list = calloc(1, sizeof(struct bus));
+	if (!domain->link_list)
+		die("%s: out of memory.\n", __func__);
+
+	struct bus *const bus = domain->link_list;
+	bus->secondary = bus_base;
+	bus->subordinate = bus->secondary;
+	bus->max_subordinate = bus_limit;
+
+	unsigned int index = 0;
+
+	if (mem32_base <= mem32_limit) {
+		struct resource *const res = new_resource(domain, index++);
+		res->base = mem32_base;
+		res->limit = mem32_limit;
+		res->size = res->limit - res->base + 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED;
+	}
+
+	if (mem64_base <= mem64_limit) {
+		struct resource *const res = new_resource(domain, index++);
+		res->base = mem64_base;
+		res->limit = mem64_limit;
+		res->size = res->limit - res->base + 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED;
+	}
+}
+
+void soc_create_ioat_domains(struct bus *const bus, const STACK_RES *const sr)
+{
+	const unsigned int domain_base = MAX_SOCKET * MAX_LOGIC_IIO_STACK;
+
+	if (sr->BusLimit < sr->BusBase + HQM_BUS_OFFSET + HQM_RESERVED_BUS) {
+		printk(BIOS_WARNING,
+			"Ignoring IOAT domain with limited bus range.\n");
+		return;
+	}
+
+	if (sr->PciResourceMem64Limit - sr->PciResourceMem64Base + 1
+	    < 2 * CPM_MMIO_SIZE + 2 * HQM_MMIO_SIZE) {
+		printk(BIOS_WARNING,
+		       "Ignoring IOAT domain with limited 64-bit MMIO window.\n");
+		return;
+	}
+
+	/* The FSP HOB doesn't provide accurate information about the
+	   resource allocation. Hence use pre-defined offsets. Based
+	   on ACPI code in create_dsdt_dino_resource(), soc_acpi.c: */
+	resource_t mem64_base, mem64_limit, bus_base, bus_limit;
+
+	/* CPM0 */
+	mem64_base = sr->PciResourceMem64Base;
+	mem64_limit = mem64_base + CPM_MMIO_SIZE - 1;
+	bus_base = sr->BusBase + CPM_BUS_OFFSET;
+	bus_limit = bus_base + CPM_RESERVED_BUS;
+	create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+
+	/* HQM0 */
+	mem64_base = mem64_limit + 1;
+	mem64_limit = mem64_base + HQM_MMIO_SIZE - 1;
+	bus_base = sr->BusBase + HQM_BUS_OFFSET;
+	bus_limit = bus_base + HQM_RESERVED_BUS;
+	create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+
+	/* CPM1 (optional) */
+	mem64_base = mem64_limit + 1;
+	mem64_limit = mem64_base + CPM_MMIO_SIZE - 1;
+	bus_base = sr->BusBase + CPM1_BUS_OFFSET;
+	bus_limit = bus_base + CPM_RESERVED_BUS;
+	if (bus_limit <= sr->BusLimit)
+		create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+
+	/* HQM1 (optional) */
+	mem64_base = mem64_limit + 1;
+	mem64_limit = mem64_base + HQM_MMIO_SIZE - 1;
+	bus_base = sr->BusBase + HQM1_BUS_OFFSET;
+	bus_limit = bus_base + HQM_RESERVED_BUS;
+	if (bus_limit <= sr->BusLimit)
+		create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+
+	/* DINO */
+	mem64_base = mem64_limit + 1;
+	mem64_limit = sr->PciResourceMem64Limit;
+	bus_base = sr->BusBase;
+	bus_limit = bus_base;
+	create_ioat_domain(bus, domain_base, bus_base, bus_limit, sr->PciResourceMem32Base, sr->PciResourceMem32Limit,
+		mem64_base, mem64_limit);
+}
diff --git a/src/soc/intel/xeon_sp/spr/soc_acpi.c b/src/soc/intel/xeon_sp/spr/soc_acpi.c
index 193b85978a..e7ce5e3773 100644
--- a/src/soc/intel/xeon_sp/spr/soc_acpi.c
+++ b/src/soc/intel/xeon_sp/spr/soc_acpi.c
@@ -188,6 +188,9 @@ static void create_dsdt_iou_cxl_resource(uint8_t socket, uint8_t stack, const ST
 
 static void create_dsdt_dino_resource(uint8_t socket, uint8_t stack, const STACK_RES *ri, bool stack_enabled)
 {
+	if (!stack_enabled)
+		return;
+
 	/*
 	   Stacks 8 .. B (TYPE_DINO)
 		Scope: DI<socket><stack> for DINO, ResourceTemplate: DT
@@ -247,6 +250,11 @@ static void create_dsdt_dino_resource(uint8_t socket, uint8_t stack, const STACK
 			snprintf(tres, sizeof(tres), "HU%d%X", socket, stack);
 		}
 
+		/* Note, some SKU doesn't provide CPM1 and HQM1 and owns smaller bus ranges
+		 accordingly*/
+		if (bus_limit > ri->BusLimit)
+			continue;
+
 		printk(BIOS_DEBUG,
 		       "\tCreating Dino ResourceTemplate %s for socket: %d, "
 		       "stack: %d\n bus_base:0x%x, bus_limit:0x%x\n",
@@ -255,30 +263,19 @@ static void create_dsdt_dino_resource(uint8_t socket, uint8_t stack, const STACK
 		acpigen_write_name(tres);
 		acpigen_write_resourcetemplate_header();
 
-		if (stack_enabled) {
-			acpigen_resource_word(2, 0xc, 0, 0, bus_base, bus_limit, 0x0,
-					      (bus_limit - bus_base + 1));
-
-			/* Mem32 resource */
-			if (rlist[i] == DSDT_DINO)
-				acpigen_resource_dword(0, 0xc, 1, 0, ri->PciResourceMem32Base,
-						       ri->PciResourceMem32Limit, 0x0,
-						       (ri->PciResourceMem32Limit
-							- ri->PciResourceMem32Base + 1));
-
-			/* Mem64 resource */
-			acpigen_resource_qword(0, 0xc, 1, 0, mem64_base, mem64_limit, 0,
-					       (mem64_limit - mem64_base + 1));
-		} else {
-			acpigen_resource_word(2, 0, 0, 0, 0, 0, 0, 0);
+		acpigen_resource_word(2, 0xc, 0, 0, bus_base, bus_limit, 0x0,
+			(bus_limit - bus_base + 1));
 
-			/* Mem32 resource */
-			if (rlist[i] == DSDT_DINO)
-				acpigen_resource_dword(0, 0, 1, 0, 0, 0, 0, 0);
+		/* Mem32 resource */
+		if (rlist[i] == DSDT_DINO)
+			acpigen_resource_dword(0, 0xc, 1, 0, ri->PciResourceMem32Base,
+				ri->PciResourceMem32Limit, 0x0,
+				(ri->PciResourceMem32Limit
+				- ri->PciResourceMem32Base + 1));
 
-			/* Mem64 resource */
-			acpigen_resource_qword(0, 0, 1, 0, 0, 0, 0, 0);
-		}
+		/* Mem64 resource */
+		acpigen_resource_qword(0, 0xc, 1, 0, mem64_base, mem64_limit, 0,
+			(mem64_limit - mem64_base + 1));
 
 		acpigen_write_resourcetemplate_footer();
 	}
diff --git a/src/soc/intel/xeon_sp/spr/soc_util.c b/src/soc/intel/xeon_sp/spr/soc_util.c
index f352145121..86fe803e85 100644
--- a/src/soc/intel/xeon_sp/spr/soc_util.c
+++ b/src/soc/intel/xeon_sp/spr/soc_util.c
@@ -68,11 +68,16 @@ const struct SystemMemoryMapElement *get_system_memory_map_elment(uint8_t *num)
 	return hob->Element;
 }
 
-bool is_iio_stack_res(const STACK_RES *res)
+bool stack_needs_resource_alloc(const STACK_RES *res)
 {
 	return res->Personality == TYPE_UBOX_IIO || res->Personality == TYPE_DINO;
 }
 
+bool is_pcie_iio_stack_res(const STACK_RES *res)
+{
+	return res->Personality == TYPE_UBOX_IIO;
+}
+
 /*
  * Given a stack resource, figure out whether the corresponding stack has
  * CXL device.
diff --git a/src/soc/intel/xeon_sp/util.c b/src/soc/intel/xeon_sp/util.c
index 86dcb970c2..c9f4c5549a 100644
--- a/src/soc/intel/xeon_sp/util.c
+++ b/src/soc/intel/xeon_sp/util.c
@@ -114,7 +114,7 @@ void get_iiostack_info(struct iiostack_resource *info)
 		for (int x = 0; x < MAX_IIO_STACK; ++x) {
 			const STACK_RES *ri;
 			ri = &hob->PlatformData.IIO_resource[socket].StackRes[x];
-			if (!is_iio_stack_res(ri))
+			if (!stack_needs_resource_alloc(ri))
 				continue;
 			assert(info->no_of_stacks < (CONFIG_MAX_SOCKET * MAX_IIO_STACK));
 			memcpy(&info->res[info->no_of_stacks++], ri, sizeof(STACK_RES));