coreboot-kgpe-d16/src/device/resource_allocator_v3.c

543 lines
16 KiB
C

/* 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)
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;
}
}
}
}