diff options
Diffstat (limited to 'src/device/resource_allocator_v3.c')
-rw-r--r-- | src/device/resource_allocator_v3.c | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/src/device/resource_allocator_v3.c b/src/device/resource_allocator_v3.c new file mode 100644 index 0000000000..4eeb2409f8 --- /dev/null +++ b/src/device/resource_allocator_v3.c @@ -0,0 +1,546 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <console/console.h> +#include <device/device.h> +#include <post.h> + +/** + * Round a number up to an alignment. + * + * @param val The starting value. + * @param pow Alignment as a power of two. + * @return Rounded up number. + */ +static resource_t round(resource_t val, unsigned long pow) +{ + resource_t mask; + mask = (1ULL << pow) - 1ULL; + val += mask; + val &= ~mask; + return val; +} + +static const char *resource2str(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"; +} + +/** + * This function is the guts of the resource allocator. + * + * The problem. + * - Allocate resource locations for every device. + * - Don't overlap, and follow the rules of bridges. + * - Don't overlap with resources in fixed locations. + * - Be efficient so we don't have ugly strategies. + * + * The strategy. + * - Devices that have fixed addresses are the minority so don't + * worry about them too much. Instead only use part of the address + * space for devices with programmable addresses. This easily handles + * everything except bridges. + * + * - PCI devices are required to have their sizes and their alignments + * equal. In this case an optimal solution to the packing problem + * exists. Allocate all devices from highest alignment to least + * alignment or vice versa. Use this. + * + * - So we can handle more than PCI run two allocation passes on bridges. The + * first to see how large the resources are behind the bridge, and what + * their alignment requirements are. The second to assign a safe address to + * the devices behind the bridge. This allows us to treat a bridge as just + * a device with a couple of resources, and not need to special case it in + * the allocator. Also this allows handling of other types of bridges. + * + * @param bus The bus we are traversing. + * @param bridge The bridge resource which must contain the bus' resources. + * @param type_mask This value gets ANDed with the resource type. + * @param type This value must match the result of the AND. + * @return TODO + */ +static void compute_resources(struct bus *bus, struct resource *bridge, + unsigned long type_mask, unsigned long type) +{ + const struct device *dev; + struct resource *resource; + resource_t base; + base = round(bridge->base, bridge->align); + + if (!bus) + return; + + printk(BIOS_SPEW, "%s %s: base: %llx size: %llx align: %d gran: %d" + " limit: %llx\n", dev_path(bus->dev), resource2str(bridge), + base, bridge->size, bridge->align, + bridge->gran, bridge->limit); + + /* For each child which is a bridge, compute the resource needs. */ + for (dev = bus->children; dev; dev = dev->sibling) { + struct resource *child_bridge; + + if (!dev->link_list) + continue; + + /* Find the resources with matching type flags. */ + for (child_bridge = dev->resource_list; child_bridge; + child_bridge = child_bridge->next) { + struct bus* link; + + if (!(child_bridge->flags & IORESOURCE_BRIDGE) + || (child_bridge->flags & type_mask) != type) + continue; + + /* + * Split prefetchable memory if combined. Many domains + * use the same address space for prefetchable memory + * and non-prefetchable memory. Bridges below them need + * it separated. Add the PREFETCH flag to the type_mask + * and type. + */ + link = dev->link_list; + while (link && link->link_num != + IOINDEX_LINK(child_bridge->index)) + link = link->next; + + if (link == NULL) { + printk(BIOS_ERR, "link %ld not found on %s\n", + IOINDEX_LINK(child_bridge->index), + dev_path(dev)); + } + + compute_resources(link, child_bridge, + type_mask | IORESOURCE_PREFETCH, + type | (child_bridge->flags & + IORESOURCE_PREFETCH)); + } + } + + /* Remember we haven't found anything yet. */ + resource = NULL; + + /* + * Walk through all the resources on the current bus and compute the + * amount of address space taken by them. Take granularity and + * alignment into account. + */ + while ((dev = largest_resource(bus, &resource, type_mask, type))) { + + /* Size 0 resources can be skipped. */ + if (!resource->size) + continue; + + /* Propagate the resource alignment to the bridge resource. */ + if (resource->align > bridge->align) + bridge->align = resource->align; + + /* Propagate the resource limit to the bridge register. */ + if (bridge->limit > resource->limit) + bridge->limit = resource->limit; + + /* Warn if it looks like APICs aren't declared. */ + if ((resource->limit == 0xffffffff) && + (resource->flags & IORESOURCE_ASSIGNED)) { + printk(BIOS_ERR, + "Resource limit looks wrong! (no APIC?)\n"); + printk(BIOS_ERR, "%s %02lx limit %08llx\n", + dev_path(dev), resource->index, resource->limit); + } + + if (resource->flags & IORESOURCE_IO) { + /* + * Don't allow potential aliases over the legacy PCI + * expansion card addresses. The legacy PCI decodes + * only 10 bits, uses 0x100 - 0x3ff. Therefore, only + * 0x00 - 0xff can be used out of each 0x400 block of + * I/O space. + */ + if ((base & 0x300) != 0) { + base = (base & ~0x3ff) + 0x400; + } + /* + * Don't allow allocations in the VGA I/O range. + * PCI has special cases for that. + */ + else if ((base >= 0x3b0) && (base <= 0x3df)) { + base = 0x3e0; + } + } + /* Base must be aligned. */ + base = round(base, resource->align); + resource->base = base; + base += resource->size; + + printk(BIOS_SPEW, "%s %02lx * [0x%llx - 0x%llx] %s\n", + dev_path(dev), resource->index, resource->base, + resource->base + resource->size - 1, + resource2str(resource)); + } + + /* + * A PCI bridge resource does not need to be a power of two size, but + * it does have a minimum granularity. Round the size up to that + * minimum granularity so we know not to place something else at an + * address positively decoded by the bridge. + */ + bridge->size = round(base, bridge->gran) - + round(bridge->base, bridge->align); + + printk(BIOS_SPEW, "%s %s: base: %llx size: %llx align: %d gran: %d" + " limit: %llx done\n", dev_path(bus->dev), + resource2str(bridge), + base, bridge->size, bridge->align, bridge->gran, bridge->limit); +} + +/** + * This function is the second part of the resource allocator. + * + * See the compute_resources function for a more detailed explanation. + * + * This function assigns the resources a value. + * + * @param bus The bus we are traversing. + * @param bridge The bridge resource which must contain the bus' resources. + * @param type_mask This value gets ANDed with the resource type. + * @param type This value must match the result of the AND. + * + * @see compute_resources + */ +static void __allocate_resources(struct bus *bus, struct resource *bridge, + unsigned long type_mask, unsigned long type) +{ + const struct device *dev; + struct resource *resource; + resource_t base; + base = bridge->base; + + if (!bus) + return; + + printk(BIOS_SPEW, "%s %s: base:%llx size:%llx align:%d gran:%d " + "limit:%llx\n", dev_path(bus->dev), + resource2str(bridge), + base, bridge->size, bridge->align, bridge->gran, bridge->limit); + + /* Remember we haven't found anything yet. */ + resource = NULL; + + /* + * Walk through all the resources on the current bus and allocate them + * address space. + */ + while ((dev = largest_resource(bus, &resource, type_mask, type))) { + + /* Propagate the bridge limit to the resource register. */ + if (resource->limit > bridge->limit) + resource->limit = bridge->limit; + + /* Size 0 resources can be skipped. */ + if (!resource->size) { + /* Set the base to limit so it doesn't confuse tolm. */ + resource->base = resource->limit; + resource->flags |= IORESOURCE_ASSIGNED; + continue; + } + + if (resource->flags & IORESOURCE_IO) { + /* + * Don't allow potential aliases over the legacy PCI + * expansion card addresses. The legacy PCI decodes + * only 10 bits, uses 0x100 - 0x3ff. Therefore, only + * 0x00 - 0xff can be used out of each 0x400 block of + * I/O space. + */ + if ((base & 0x300) != 0) { + base = (base & ~0x3ff) + 0x400; + } + /* + * Don't allow allocations in the VGA I/O range. + * PCI has special cases for that. + */ + else if ((base >= 0x3b0) && (base <= 0x3df)) { + base = 0x3e0; + } + } + + if ((round(base, resource->align) + resource->size - 1) <= + resource->limit) { + /* Base must be aligned. */ + base = round(base, resource->align); + resource->base = base; + resource->limit = resource->base + resource->size - 1; + resource->flags |= IORESOURCE_ASSIGNED; + resource->flags &= ~IORESOURCE_STORED; + base += resource->size; + } else { + printk(BIOS_ERR, "!! Resource didn't fit !!\n"); + printk(BIOS_ERR, " aligned base %llx size %llx " + "limit %llx\n", round(base, resource->align), + resource->size, resource->limit); + printk(BIOS_ERR, " %llx needs to be <= %llx " + "(limit)\n", (round(base, resource->align) + + resource->size) - 1, resource->limit); + printk(BIOS_ERR, " %s%s %02lx * [0x%llx - 0x%llx]" + " %s\n", (resource->flags & IORESOURCE_ASSIGNED) + ? "Assigned: " : "", dev_path(dev), + resource->index, resource->base, + resource->base + resource->size - 1, + resource2str(resource)); + } + + printk(BIOS_SPEW, "%s %02lx * [0x%llx - 0x%llx] %s\n", + dev_path(dev), resource->index, resource->base, + resource->size ? resource->base + resource->size - 1 : + resource->base, resource2str(resource)); + } + + /* + * A PCI bridge resource does not need to be a power of two size, but + * it does have a minimum granularity. Round the size up to that + * minimum granularity so we know not to place something else at an + * address positively decoded by the bridge. + */ + + bridge->flags |= IORESOURCE_ASSIGNED; + + printk(BIOS_SPEW, "%s %s: next_base: %llx size: %llx align: %d " + "gran: %d done\n", dev_path(bus->dev), + resource2str(bridge), base, bridge->size, bridge->align, + bridge->gran); + + /* For each child which is a bridge, __allocate_resources. */ + for (dev = bus->children; dev; dev = dev->sibling) { + struct resource *child_bridge; + + if (!dev->link_list) + continue; + + /* Find the resources with matching type flags. */ + for (child_bridge = dev->resource_list; child_bridge; + child_bridge = child_bridge->next) { + struct bus* link; + + if (!(child_bridge->flags & IORESOURCE_BRIDGE) || + (child_bridge->flags & type_mask) != type) + continue; + + /* + * Split prefetchable memory if combined. Many domains + * use the same address space for prefetchable memory + * and non-prefetchable memory. Bridges below them need + * it separated. Add the PREFETCH flag to the type_mask + * and type. + */ + link = dev->link_list; + while (link && link->link_num != + IOINDEX_LINK(child_bridge->index)) + link = link->next; + if (link == NULL) + printk(BIOS_ERR, "link %ld not found on %s\n", + IOINDEX_LINK(child_bridge->index), + dev_path(dev)); + + __allocate_resources(link, child_bridge, + type_mask | IORESOURCE_PREFETCH, + type | (child_bridge->flags & + IORESOURCE_PREFETCH)); + } + } +} + +static int resource_is(struct resource *res, u32 type) +{ + return (res->flags & IORESOURCE_TYPE_MASK) == type; +} + +struct constraints { + struct resource io, mem; +}; + +static struct resource *resource_limit(struct constraints *limits, + struct resource *res) +{ + struct resource *lim = NULL; + + /* MEM, or I/O - skip any others. */ + if (resource_is(res, IORESOURCE_MEM)) + lim = &limits->mem; + else if (resource_is(res, IORESOURCE_IO)) + lim = &limits->io; + + return lim; +} + +static void constrain_resources(const struct device *dev, + struct constraints* limits) +{ + const struct device *child; + struct resource *res; + struct resource *lim; + struct bus *link; + + /* Constrain limits based on the fixed resources of this device. */ + for (res = dev->resource_list; res; res = res->next) { + if (!(res->flags & IORESOURCE_FIXED)) + continue; + if (!res->size) { + /* It makes no sense to have 0-sized, fixed resources.*/ + printk(BIOS_ERR, "skipping %s@%lx fixed resource, " + "size=0!\n", dev_path(dev), res->index); + continue; + } + + lim = resource_limit(limits, res); + if (!lim) + continue; + + /* + * Is it a fixed resource outside the current known region? + * If so, we don't have to consider it - it will be handled + * correctly and doesn't affect current region's limits. + */ + if (((res->base + res->size -1) < lim->base) + || (res->base > lim->limit)) + continue; + + printk(BIOS_SPEW, "%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)); + + /* + * Choose to be above or below fixed resources. This check is + * signed so that "negative" amounts of space are handled + * correctly. + */ + if ((signed long long)(lim->limit - (res->base + res->size -1)) + > (signed long long)(res->base - lim->base)) + lim->base = res->base + res->size; + else + lim->limit = res->base -1; + } + + /* Descend into every enabled child and look for fixed resources. */ + for (link = dev->link_list; link; link = link->next) { + for (child = link->children; child; child = child->sibling) { + if (child->enabled) + constrain_resources(child, limits); + } + } +} + +static void avoid_fixed_resources(const struct device *dev) +{ + struct constraints limits; + struct resource *res; + struct resource *lim; + + printk(BIOS_SPEW, "%s: %s\n", __func__, dev_path(dev)); + + /* Initialize constraints to maximum size. */ + limits.io.base = 0; + limits.io.limit = 0xffffffffffffffffULL; + limits.mem.base = 0; + limits.mem.limit = 0xffffffffffffffffULL; + + /* Constrain the limits to dev's initial resources. */ + for (res = dev->resource_list; res; res = res->next) { + if ((res->flags & IORESOURCE_FIXED)) + continue; + printk(BIOS_SPEW, "%s:@%s %02lx limit %08llx\n", __func__, + dev_path(dev), res->index, res->limit); + + lim = resource_limit(&limits, res); + if (!lim) + continue; + + if (res->base > lim->base) + lim->base = res->base; + if (res->limit < lim->limit) + lim->limit = res->limit; + } + + /* Look through the tree for fixed resources and update the limits. */ + constrain_resources(dev, &limits); + + /* Update dev's resources with new limits. */ + for (res = dev->resource_list; res; res = res->next) { + if ((res->flags & IORESOURCE_FIXED)) + continue; + + lim = resource_limit(&limits, res); + if (!lim) + continue; + + /* Is the resource outside the limits? */ + if (lim->base > res->base) + res->base = lim->base; + if (res->limit > lim->limit) + res->limit = lim->limit; + + /* MEM resources need to start at the highest address manageable. */ + if (res->flags & IORESOURCE_MEM) + res->base = resource_max(res); + + printk(BIOS_SPEW, "%s:@%s %02lx base %08llx limit %08llx\n", + __func__, dev_path(dev), res->index, res->base, res->limit); + } +} + +void allocate_resources(const struct device *root) +{ + struct resource *res; + const struct device *child; + + /* Compute resources for all domains. */ + for (child = root->link_list->children; child; child = child->sibling) { + if (!(child->path.type == DEVICE_PATH_DOMAIN)) + continue; + post_log_path(child); + for (res = child->resource_list; res; res = res->next) { + if (res->flags & IORESOURCE_FIXED) + continue; + if (res->flags & IORESOURCE_MEM) { + compute_resources(child->link_list, + res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM); + continue; + } + if (res->flags & IORESOURCE_IO) { + compute_resources(child->link_list, + res, IORESOURCE_TYPE_MASK, IORESOURCE_IO); + continue; + } + } + } + + /* For all domains. */ + for (child = root->link_list->children; child; child=child->sibling) + if (child->path.type == DEVICE_PATH_DOMAIN) + avoid_fixed_resources(child); + + /* Store the computed resource allocations into device registers ... */ + printk(BIOS_INFO, "Setting resources...\n"); + for (child = root->link_list->children; child; child = child->sibling) { + if (!(child->path.type == DEVICE_PATH_DOMAIN)) + continue; + post_log_path(child); + for (res = child->resource_list; res; res = res->next) { + if (res->flags & IORESOURCE_FIXED) + continue; + if (res->flags & IORESOURCE_MEM) { + __allocate_resources(child->link_list, + res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM); + continue; + } + if (res->flags & IORESOURCE_IO) { + __allocate_resources(child->link_list, + res, IORESOURCE_TYPE_MASK, IORESOURCE_IO); + continue; + } + } + } +} |