soc/intel/alderlake: Add ADL-P 4+4 with 28W TDP

[coreboot.git] / src / device / resource_allocator_v4.c

/* SPDX-License-Identifier: GPL-2.0-only */

#include <commonlib/bsd/helpers.h>
#include <console/console.h>
#include <device/device.h>
#include <memrange.h>
#include <post.h>
#include <types.h>

static const char *resource2str(const struct resource *res)
{
        if (res->flags & IORESOURCE_IO)
                return "io";
        if (res->flags & IORESOURCE_PREFETCH)
                return "prefmem";
        if (res->flags & IORESOURCE_MEM)
                return "mem";
        return "undefined";
}

static bool dev_has_children(const struct device *dev)
{
        const struct bus *bus = dev->link_list;
        return bus && bus->children;
}

#define res_printk(depth, str, ...)     printk(BIOS_DEBUG, "%*c"str, depth, ' ', __VA_ARGS__)

/*
 * During pass 1, once all the requirements for downstream devices of a
 * bridge are gathered, this function calculates the overall resource
 * requirement for the bridge. It starts by picking the largest resource
 * requirement downstream for the given resource type and works by
 * adding requirements in descending order.
 *
 * Additionally, it takes alignment and limits of the downstream devices
 * into consideration and ensures that they get propagated to the bridge
 * resource. This is required to guarantee that the upstream bridge/
 * domain honors the limit and alignment requirements for this bridge
 * based on the tightest constraints downstream.
 */
static void update_bridge_resource(const struct device *bridge, struct resource *bridge_res,
                                   unsigned long type_match, int print_depth)
{
        const struct device *child;
        struct resource *child_res;
        resource_t base;
        const unsigned long type_mask = IORESOURCE_TYPE_MASK | IORESOURCE_PREFETCH;
        struct bus *bus = bridge->link_list;

        child_res = NULL;

        /*
         * `base` keeps track of where the next allocation for child resources
         * can take place from within the bridge resource window. Since the
         * bridge resource window allocation is not performed yet, it can start
         * at 0. Base gets updated every time a resource requirement is
         * accounted for in the loop below. After scanning all these resources,
         * base will indicate the total size requirement for the current bridge
         * resource window.
         */
        base = 0;

        res_printk(print_depth, "%s %s: size: %llx align: %d gran: %d limit: %llx\n",
               dev_path(bridge), resource2str(bridge_res), bridge_res->size,
               bridge_res->align, bridge_res->gran, bridge_res->limit);

        while ((child = largest_resource(bus, &child_res, type_mask, type_match))) {

                /* Size 0 resources can be skipped. */
                if (!child_res->size)
                        continue;

                /* Resources with 0 limit can't be assigned anything. */
                if (!child_res->limit)
                        continue;

                /*
                 * Propagate the resource alignment to the bridge resource. The
                 * condition can only be true for the first (largest) resource. For all
                 * other children resources, alignment is taken care of by updating the
                 * base to round up as per the child resource alignment. It is
                 * guaranteed that pass 2 follows the exact same method of picking the
                 * resource for allocation using largest_resource(). Thus, as long as
                 * the alignment for the largest child resource is propagated up to the
                 * bridge resource, it can be guaranteed that the alignment for all
                 * resources is appropriately met.
                 */
                if (child_res->align > bridge_res->align)
                        bridge_res->align = child_res->align;

                /*
                 * Propagate the resource limit to the bridge resource. If a downstream
                 * device has stricter requirements w.r.t. limits for any resource, that
                 * constraint needs to be propagated back up to the downstream bridges
                 * of the domain. This guarantees that the resource allocation which
                 * starts at the domain level takes into account all these constraints
                 * thus working on a global view.
                 */
                if (child_res->limit < bridge_res->limit)
                        bridge_res->limit = child_res->limit;

                /*
                 * Propagate the downstream resource request to allocate above 4G
                 * boundary to upstream bridge resource. This ensures that during
                 * pass 2, the resource allocator at domain level has a global view
                 * of all the downstream device requirements and thus address space
                 * is allocated as per updated flags in the bridge resource.
                 *
                 * Since the bridge resource is a single window, all the downstream
                 * resources of this bridge resource will be allocated in space above
                 * the 4G boundary.
                 */
                if (child_res->flags & IORESOURCE_ABOVE_4G)
                        bridge_res->flags |= IORESOURCE_ABOVE_4G;

                /*
                 * Alignment value of 0 means that the child resource has no alignment
                 * requirements and so the base value remains unchanged here.
                 */
                base = ALIGN_UP(base, POWER_OF_2(child_res->align));

                res_printk(print_depth + 1, "%s %02lx *  [0x%llx - 0x%llx] %s\n",
                       dev_path(child), child_res->index, base, base + child_res->size - 1,
                       resource2str(child_res));

                base += child_res->size;
        }

        /*
         * After all downstream device resources are scanned, `base` represents
         * the total size requirement for the current bridge resource window.
         * This size needs to be rounded up to the granularity requirement of
         * the bridge to ensure that the upstream bridge/domain allocates big
         * enough window.
         */
        bridge_res->size = ALIGN_UP(base, POWER_OF_2(bridge_res->gran));

        res_printk(print_depth, "%s %s: size: %llx align: %d gran: %d limit: %llx done\n",
               dev_path(bridge), resource2str(bridge_res), bridge_res->size,
               bridge_res->align, bridge_res->gran, bridge_res->limit);
}

/*
 * During pass 1, at the bridge level, the resource allocator gathers
 * requirements from downstream devices and updates its own resource
 * windows for the provided resource type.
 */
static void compute_bridge_resources(const struct device *bridge, unsigned long type_match,
                                     int print_depth)
{
        const struct device *child;
        struct resource *res;
        struct bus *bus = bridge->link_list;
        const unsigned long type_mask = IORESOURCE_TYPE_MASK | IORESOURCE_PREFETCH;

        for (res = bridge->resource_list; res; res = res->next) {
                if (!(res->flags & IORESOURCE_BRIDGE))
                        continue;

                if ((res->flags & type_mask) != type_match)
                        continue;

                /*
                 * Ensure that the resource requirements for all downstream bridges are
                 * gathered before updating the window for current bridge resource.
                 */
                for (child = bus->children; child; child = child->sibling) {
                        if (!dev_has_children(child))
                                continue;
                        compute_bridge_resources(child, type_match, print_depth + 1);
                }

                /*
                 * Update the window for current bridge resource now that all downstream
                 * requirements are gathered.
                 */
                update_bridge_resource(bridge, res, type_match, print_depth);
        }
}

/*
 * During pass 1, the resource allocator walks down the entire sub-tree
 * of a domain. It gathers resource requirements for every downstream
 * bridge by looking at the resource requests of its children. Thus, the
 * requirement gathering begins at the leaf devices and is propagated
 * back up to the downstream bridges of the domain.
 *
 * At the domain level, it identifies every downstream bridge and walks
 * down that bridge to gather requirements for each resource type i.e.
 * i/o, mem and prefmem. Since bridges have separate windows for mem and
 * prefmem, requirements for each need to be collected separately.
 *
 * Domain resource windows are fixed ranges and hence requirement
 * gathering does not result in any changes to these fixed ranges.
 */
static void compute_domain_resources(const struct device *domain)
{
        const struct device *child;
        const int print_depth = 1;

        if (domain->link_list == NULL)
                return;

        for (child = domain->link_list->children; child; child = child->sibling) {

                /* Skip if this is not a bridge or has no children under it. */
                if (!dev_has_children(child))
                        continue;

                compute_bridge_resources(child, IORESOURCE_IO, print_depth);
                compute_bridge_resources(child, IORESOURCE_MEM, print_depth);
                compute_bridge_resources(child, IORESOURCE_MEM | IORESOURCE_PREFETCH,
                                         print_depth);
        }
}

static unsigned char get_alignment_by_resource_type(const struct resource *res)
{
        if (res->flags & IORESOURCE_MEM)
                return 12;  /* Page-aligned --> log2(4KiB) */
        else if (res->flags & IORESOURCE_IO)
                return 0;   /* No special alignment required --> log2(1) */

        die("Unexpected resource type: flags(%d)!\n", res->flags);
}

/*
 * If the resource is NULL or if the resource is not assigned, then it
 * cannot be used for allocation for downstream devices.
 */
static bool is_resource_invalid(const struct resource *res)
{
        return (res == NULL) || !(res->flags & IORESOURCE_ASSIGNED);
}

static void initialize_domain_io_resource_memranges(struct memranges *ranges,
                                                    const struct resource *res,
                                                    unsigned long memrange_type)
{
        memranges_insert(ranges, res->base, res->limit - res->base + 1, memrange_type);
}

static void initialize_domain_mem_resource_memranges(struct memranges *ranges,
                                                     const struct resource *res,
                                                     unsigned long memrange_type)
{
        resource_t res_base;
        resource_t res_limit;

        const resource_t limit_4g = 0xffffffff;

        res_base = res->base;
        res_limit = res->limit;

        /*
         * Split the resource into two separate ranges if it crosses the 4G
         * boundary. Memrange type is set differently to ensure that memrange
         * does not merge these two ranges. For the range above 4G boundary,
         * given memrange type is ORed with IORESOURCE_ABOVE_4G.
         */
        if (res_base <= limit_4g) {

                resource_t range_limit;

                /* Clip the resource limit at 4G boundary if necessary. */
                range_limit = MIN(res_limit, limit_4g);
                memranges_insert(ranges, res_base, range_limit - res_base + 1, memrange_type);

                /*
                 * If the resource lies completely below the 4G boundary, nothing more
                 * needs to be done.
                 */
                if (res_limit <= limit_4g)
                        return;

                /*
                 * If the resource window crosses the 4G boundary, then update res_base
                 * to add another entry for the range above the boundary.
                 */
                res_base = limit_4g + 1;
        }

        if (res_base > res_limit)
                return;

        /*
         * If resource lies completely above the 4G boundary or if the resource
         * was clipped to add two separate ranges, the range above 4G boundary
         * has the resource flag IORESOURCE_ABOVE_4G set. This allows domain to
         * handle any downstream requests for resource allocation above 4G
         * differently.
         */
        memranges_insert(ranges, res_base, res_limit - res_base + 1,
                         memrange_type | IORESOURCE_ABOVE_4G);
}

/*
 * This function initializes memranges for domain device. If the
 * resource crosses 4G boundary, then this function splits it into two
 * ranges -- one for the window below 4G and the other for the window
 * above 4G. The latter range has IORESOURCE_ABOVE_4G flag set to
 * satisfy resource requests from downstream devices for allocations
 * above 4G.
 */
static void initialize_domain_memranges(struct memranges *ranges, const struct resource *res,
                                        unsigned long memrange_type)
{
        unsigned char align = get_alignment_by_resource_type(res);

        memranges_init_empty_with_alignment(ranges, NULL, 0, align);

        if (is_resource_invalid(res))
                return;

        if (res->flags & IORESOURCE_IO)
                initialize_domain_io_resource_memranges(ranges, res, memrange_type);
        else
                initialize_domain_mem_resource_memranges(ranges, res, memrange_type);
}

/*
 * This function initializes memranges for bridge device. Unlike domain,
 * bridge does not need to care about resource window crossing 4G
 * boundary. This is handled by the resource allocator at domain level
 * to ensure that all downstream bridges are allocated space either
 * above or below 4G boundary as per the state of IORESOURCE_ABOVE_4G
 * for the respective bridge resource.
 *
 * So, this function creates a single range of the entire resource
 * window available for the bridge resource. Thus all downstream
 * resources of the bridge for the given resource type get allocated
 * space from the same window. If there is any downstream resource of
 * the bridge which requests allocation above 4G, then all other
 * downstream resources of the same type under the bridge get allocated
 * above 4G.
 */
static void initialize_bridge_memranges(struct memranges *ranges, const struct resource *res,
                                        unsigned long memrange_type)
{
        unsigned char align = get_alignment_by_resource_type(res);

        memranges_init_empty_with_alignment(ranges, NULL, 0, align);

        if (is_resource_invalid(res))
                return;

        memranges_insert(ranges, res->base, res->limit - res->base + 1, memrange_type);
}

static void print_resource_ranges(const struct device *dev, const struct memranges *ranges)
{
        const struct range_entry *r;

        printk(BIOS_INFO, " %s: Resource ranges:\n", dev_path(dev));

        if (memranges_is_empty(ranges))
                printk(BIOS_INFO, " * EMPTY!!\n");

        memranges_each_entry(r, ranges) {
                printk(BIOS_INFO, " * Base: %llx, Size: %llx, Tag: %lx\n",
                       range_entry_base(r), range_entry_size(r), range_entry_tag(r));
        }
}

/*
 * This is where the actual allocation of resources happens during
 * pass 2. Given the list of memory ranges corresponding to the
 * resource of given type, it finds the biggest unallocated resource
 * using the type mask on the downstream bus. This continues in a
 * descending order until all resources of given type are allocated
 * address space within the current resource window.
 */
static void allocate_child_resources(struct bus *bus, struct memranges *ranges,
                                     unsigned long type_mask, unsigned long type_match)
{
        const bool allocate_top_down =
                bus->dev->path.type == DEVICE_PATH_DOMAIN &&
                CONFIG(RESOURCE_ALLOCATION_TOP_DOWN);
        struct resource *resource = NULL;
        const struct device *dev;

        while ((dev = largest_resource(bus, &resource, type_mask, type_match))) {

                if (!resource->size)
                        continue;

                if (memranges_steal(ranges, resource->limit, resource->size, resource->align,
                                    type_match, &resource->base, allocate_top_down) == false) {
                        printk(BIOS_ERR, "  ERROR: Resource didn't fit!!! ");
                        printk(BIOS_DEBUG, "  %s %02lx *  size: 0x%llx limit: %llx %s\n",
                               dev_path(dev), resource->index,
                               resource->size, resource->limit, resource2str(resource));
                        continue;
                }

                resource->limit = resource->base + resource->size - 1;
                resource->flags |= IORESOURCE_ASSIGNED;

                printk(BIOS_DEBUG, "  %s %02lx *  [0x%llx - 0x%llx] limit: %llx %s\n",
                       dev_path(dev), resource->index, resource->base,
                       resource->size ? resource->base + resource->size - 1 :
                       resource->base, resource->limit, resource2str(resource));
        }
}

static void update_constraints(struct memranges *ranges, const struct device *dev,
                              const struct resource *res)
{
        if (!res->size)
                return;

        printk(BIOS_DEBUG, " %s: %s %02lx base %08llx limit %08llx %s (fixed)\n",
               __func__, dev_path(dev), res->index, res->base,
               res->base + res->size - 1, resource2str(res));

        memranges_create_hole(ranges, res->base, res->size);
}

/*
 * Scan the entire tree to identify any fixed resources allocated by
 * any device to ensure that the address map for domain resources are
 * appropriately updated.
 *
 * Domains can typically provide a memrange for entire address space.
 * So, this function punches holes in the address space for all fixed
 * resources that are already defined. Both I/O and normal memory
 * resources are added as fixed. Both need to be removed from address
 * space where dynamic resource allocations are sourced.
 */
static void avoid_fixed_resources(struct memranges *ranges, const struct device *dev,
                                  unsigned long mask_match)
{
        const struct resource *res;
        const struct device *child;
        const struct bus *bus;

        for (res = dev->resource_list; res != NULL; res = res->next) {
                if ((res->flags & mask_match) != mask_match)
                        continue;
                update_constraints(ranges, dev, res);
        }

        bus = dev->link_list;
        if (bus == NULL)
                return;

        for (child = bus->children; child != NULL; child = child->sibling)
                avoid_fixed_resources(ranges, child, mask_match);
}

static void constrain_domain_resources(const struct device *domain, struct memranges *ranges,
                                       unsigned long type)
{
        unsigned long mask_match = type | IORESOURCE_FIXED;

        if (type == IORESOURCE_IO) {
                /*
                 * Don't allow allocations in the VGA I/O range. PCI has special
                 * cases for that.
                 */
                memranges_create_hole(ranges, 0x3b0, 0x3df - 0x3b0 + 1);

                /*
                 * Resource allocator no longer supports the legacy behavior where
                 * I/O resource allocation is guaranteed to avoid aliases over legacy
                 * PCI expansion card addresses.
                 */
        }

        avoid_fixed_resources(ranges, domain, mask_match);
}

/*
 * This function creates a list of memranges of given type using the
 * resource that is provided. If the given resource is NULL or if the
 * resource window size is 0, then it creates an empty list. This
 * results in resource allocation for that resource type failing for
 * all downstream devices since there is nothing to allocate from.
 *
 * In case of domain, it applies additional constraints to ensure that
 * the memranges do not overlap any of the fixed resources under that
 * domain. Domain typically seems to provide memrange for entire address
 * space. Thus, it is up to the chipset to add DRAM and all other
 * windows which cannot be used for resource allocation as fixed
 * resources.
 */
static void setup_resource_ranges(const struct device *dev, const struct resource *res,
                                  unsigned long type, struct memranges *ranges)
{
        printk(BIOS_DEBUG, "%s %s: base: %llx size: %llx align: %d gran: %d limit: %llx\n",
               dev_path(dev), resource2str(res), res->base, res->size, res->align,
               res->gran, res->limit);

        if (dev->path.type == DEVICE_PATH_DOMAIN) {
                initialize_domain_memranges(ranges, res, type);
                constrain_domain_resources(dev, ranges, type);
        } else {
                initialize_bridge_memranges(ranges, res, type);
        }

        print_resource_ranges(dev, ranges);
}

static void cleanup_resource_ranges(const struct device *dev, struct memranges *ranges,
                                    const struct resource *res)
{
        memranges_teardown(ranges);
        printk(BIOS_DEBUG, "%s %s: base: %llx size: %llx align: %d gran: %d limit: %llx done\n",
               dev_path(dev), resource2str(res), res->base, res->size, res->align,
               res->gran, res->limit);
}

/*
 * Pass 2 of the resource allocator at the bridge level loops through
 * all the resources for the bridge and generates a list of memory
 * ranges similar to that at the domain level. However, there is no need
 * to apply any additional constraints since the window allocated to the
 * bridge is guaranteed to be non-overlapping by the allocator at domain
 * level.
 *
 * Allocation at the bridge level works the same as at domain level
 * (starts with the biggest resource requirement from downstream devices
 * and continues in descending order). One major difference at the
 * bridge level is that it considers prefmem resources separately from
 * mem resources.
 *
 * Once allocation at the current bridge is complete, resource allocator
 * continues walking down the downstream bridges until it hits the leaf
 * devices.
 */
static void allocate_bridge_resources(const struct device *bridge)
{
        struct memranges ranges;
        const struct resource *res;
        struct bus *bus = bridge->link_list;
        unsigned long type_match;
        struct device *child;
        const unsigned long type_mask = IORESOURCE_TYPE_MASK | IORESOURCE_PREFETCH;

        for (res = bridge->resource_list; res; res = res->next) {
                if (!res->size)
                        continue;

                if (!(res->flags & IORESOURCE_BRIDGE))
                        continue;

                type_match = res->flags & type_mask;

                setup_resource_ranges(bridge, res, type_match, &ranges);
                allocate_child_resources(bus, &ranges, type_mask, type_match);
                cleanup_resource_ranges(bridge, &ranges, res);
        }

        for (child = bus->children; child; child = child->sibling) {
                if (!dev_has_children(child))
                        continue;

                allocate_bridge_resources(child);
        }
}

static const struct resource *find_domain_resource(const struct device *domain,
                                                   unsigned long type)
{
        const struct resource *res;

        for (res = domain->resource_list; res; res = res->next) {
                if (res->flags & IORESOURCE_FIXED)
                        continue;

                if ((res->flags & IORESOURCE_TYPE_MASK) == type)
                        return res;
        }

        return NULL;
}

/*
 * Pass 2 of resource allocator begins at the domain level. Every domain
 * has two types of resources - io and mem. For each of these resources,
 * this function creates a list of memory ranges that can be used for
 * downstream resource allocation. This list is constrained to remove
 * any fixed resources in the domain sub-tree of the given resource
 * type. It then uses the memory ranges to apply best fit on the
 * resource requirements of the downstream devices.
 *
 * Once resources are allocated to all downstream devices of the domain,
 * it walks down each downstream bridge to continue the same process
 * until resources are allocated to all devices under the domain.
 */
static void allocate_domain_resources(const struct device *domain)
{
        struct memranges ranges;
        struct device *child;
        const struct resource *res;

        /* Resource type I/O */
        res = find_domain_resource(domain, IORESOURCE_IO);
        if (res) {
                setup_resource_ranges(domain, res, IORESOURCE_IO, &ranges);
                allocate_child_resources(domain->link_list, &ranges, IORESOURCE_TYPE_MASK,
                                         IORESOURCE_IO);
                cleanup_resource_ranges(domain, &ranges, res);
        }

        /*
         * Resource type Mem:
         * Domain does not distinguish between mem and prefmem resources. Thus,
         * the resource allocation at domain level considers mem and prefmem
         * together when finding the best fit based on the biggest resource
         * requirement.
         *
         * However, resource requests for allocation above 4G boundary need to
         * be handled separately if the domain resource window crosses this
         * boundary. There is a single window for resource of type
         * IORESOURCE_MEM. When creating memranges, this resource is split into
         * two separate ranges -- one for the window below 4G boundary and other
         * for the window above 4G boundary (with IORESOURCE_ABOVE_4G flag set).
         * Thus, when allocating child resources, requests for below and above
         * the 4G boundary are handled separately by setting the type_mask and
         * type_match to allocate_child_resources() accordingly.
         */
        res = find_domain_resource(domain, IORESOURCE_MEM);
        if (res) {
                setup_resource_ranges(domain, res, IORESOURCE_MEM, &ranges);
                allocate_child_resources(domain->link_list, &ranges,
                                         IORESOURCE_TYPE_MASK | IORESOURCE_ABOVE_4G,
                                         IORESOURCE_MEM);
                allocate_child_resources(domain->link_list, &ranges,
                                         IORESOURCE_TYPE_MASK | IORESOURCE_ABOVE_4G,
                                         IORESOURCE_MEM | IORESOURCE_ABOVE_4G);
                cleanup_resource_ranges(domain, &ranges, res);
        }

        for (child = domain->link_list->children; child; child = child->sibling) {
                if (!dev_has_children(child))
                        continue;

                /* Continue allocation for all downstream bridges. */
                allocate_bridge_resources(child);
        }
}

/*
 * This function forms the guts of the resource allocator. It walks
 * through the entire device tree for each domain two times.
 *
 * Every domain has a fixed set of ranges. These ranges cannot be
 * relaxed based on the requirements of the downstream devices. They
 * represent the available windows from which resources can be allocated
 * to the different devices under the domain.
 *
 * In order to identify the requirements of downstream devices, resource
 * allocator walks in a DFS fashion. It gathers the requirements from
 * leaf devices and propagates those back up to their upstream bridges
 * until the requirements for all the downstream devices of the domain
 * are gathered. This is referred to as pass 1 of the resource allocator.
 *
 * Once the requirements for all the devices under the domain are
 * gathered, the resource allocator walks a second time to allocate
 * resources to downstream devices as per the requirements. It always
 * picks the biggest resource request as per the type (i/o and mem) to
 * allocate space from its fixed window to the immediate downstream
 * device of the domain. In order to accomplish best fit for the
 * resources, a list of ranges is maintained by each resource type (i/o
 * and mem). At the domain level we don't differentiate between mem and
 * prefmem. Since they are allocated space from the same window, the
 * resource allocator at the domain level ensures that the biggest
 * requirement is selected independent of the prefetch type. Once the
 * resource allocation for all immediate downstream devices is complete
 * at the domain level, the resource allocator walks down the subtree
 * for each downstream bridge to continue the allocation process at the
 * bridge level. Since bridges have separate windows for i/o, mem and
 * prefmem, best fit algorithm at bridge level looks for the biggest
 * requirement considering prefmem resources separately from non-prefmem
 * resources. This continues until resource allocation is performed for
 * all downstream bridges in the domain sub-tree. This is referred to as
 * pass 2 of the resource allocator.
 *
 * Some rules that are followed by the resource allocator:
 *  - Allocate resource locations for every device as long as
 *    the requirements can be satisfied.
 *  - Don't overlap with resources in fixed locations.
 *  - Don't overlap and follow the rules of bridges -- downstream
 *    devices of bridges should use parts of the address space
 *    allocated to the bridge.
 */
void allocate_resources(const struct device *root)
{
        const struct device *child;

        if ((root == NULL) || (root->link_list == NULL))
                return;

        for (child = root->link_list->children; child; child = child->sibling) {

                if (child->path.type != DEVICE_PATH_DOMAIN)
                        continue;

                post_log_path(child);

                /* Pass 1 - Gather requirements. */
                printk(BIOS_INFO, "=== Resource allocator: %s - Pass 1 (gathering requirements) ===\n",
                       dev_path(child));
                compute_domain_resources(child);

                /* Pass 2 - Allocate resources as per gathered requirements. */
                printk(BIOS_INFO, "=== Resource allocator: %s - Pass 2 (allocating resources) ===\n",
                       dev_path(child));
                allocate_domain_resources(child);

                printk(BIOS_INFO, "=== Resource allocator: %s - resource allocation complete ===\n",
                       dev_path(child));
        }
}