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

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/*
* (c) 1999--2000 Martin Mares <mj@suse.cz>
* (c) 2003 Eric Biederman <ebiederm@xmission.com>
* (c) 2003 Linux Networx
*/
/* lots of mods by ron minnich (rminnich@lanl.gov), with
* the final architecture guidance from Tom Merritt (tjm@codegen.com)
* In particular, we changed from the one-pass original version to
* Tom's recommended multiple-pass version. I wasn't sure about doing
* it with multiple passes, until I actually started doing it and saw
* the wisdom of Tom's recommendations ...
*
* Lots of cleanups by Eric Biederman to handle bridges, and to
* handle resource allocation for non-pci devices.
*/
#include <console/console.h>
#include <bitops.h>
#include <arch/io.h>
#include <device/device.h>
#include <device/pci.h>
#include <stdlib.h>
#include <string.h>
/* Linked list of ALL devices */
struct device *all_devices = 0;
/* pointer to the last device */
static struct device **last_dev_p = &all_devices;
#define DEVICE_MEM_HIGH 0xFEC00000UL /* Reserve 20M for the system */
#define DEVICE_IO_START 0x1000
/** Allocate a new device structure
*/
device_t alloc_dev(struct bus *parent, struct device_path *path)
{
device_t dev, child;
int link;
/* Find the last child of our parent */
for(child = parent->children; child && child->sibling; ) {
child = child->sibling;
}
dev = malloc(sizeof(*dev));
if (dev == 0) {
die("DEV: out of memory.\n");
}
memset(dev, 0, sizeof(*dev));
memcpy(&dev->path, path, sizeof(*path));
/* Append a new device to the global device chain.
* The chain is used to find devices once everything is set up.
*/
*last_dev_p = dev;
last_dev_p = &dev->next;
/* Initialize the back pointers in the link fields */
for(link = 0; link < MAX_LINKS; link++) {
dev->link[link].dev = dev;
dev->link[link].link = link;
}
/* Add the new device to the children of the bus. */
dev->bus = parent;
if (child) {
child->sibling = dev;
} else {
parent->children = dev;
}
/* If we don't have any other information about a device enable it */
dev->enable = 1;
return dev;
}
/** round a number to an alignment.
* @param val the starting value
* @param roundup Alignment as a power of two
* @returns rounded up number
*/
static unsigned long round(unsigned long val, unsigned long roundup)
{
/* ROUNDUP MUST BE A POWER OF TWO. */
unsigned long inverse;
inverse = ~(roundup - 1);
val += (roundup - 1);
val &= inverse;
return val;
}
static unsigned long round_down(unsigned long val, unsigned long round_down)
{
/* ROUND_DOWN MUST BE A POWER OF TWO. */
unsigned long inverse;
inverse = ~(round_down - 1);
val &= inverse;
return val;
}
/** Read the resources on all devices of a given bus.
* @param bus bus to read the resources on.
*/
static void read_resources(struct bus *bus)
{
struct device *curdev;
/* Walk through all of the devices and find which resources they need. */
for(curdev = bus->children; curdev; curdev = curdev->sibling) {
unsigned links;
int i;
if (curdev->resources > 0) {
continue;
}
if (!curdev->ops || !curdev->ops->read_resources) {
printk_err("%s missing read_resources\n",
dev_path(curdev));
continue;
}
curdev->ops->read_resources(curdev);
/* Read in subtractive resources behind the current device */
links = 0;
for(i = 0; i < curdev->resources; i++) {
struct resource *resource;
resource = &curdev->resource[i];
if ((resource->flags & IORESOURCE_SUBTRACTIVE) &&
(!(links & (1 << resource->index))))
{
links |= (1 << resource->index);
read_resources(&curdev->link[resource->index]);
}
}
}
}
struct pick_largest_state {
struct resource *last;
struct device *result_dev;
struct resource *result;
int seen_last;
};
static void pick_largest_resource(
struct pick_largest_state *state, struct device *dev, struct resource *resource)
{
struct resource *last;
last = state->last;
/* Be certain to pick the successor to last */
if (resource == last) {
state->seen_last = 1;
return;
}
if (last && (
(last->align < resource->align) ||
((last->align == resource->align) &&
(last->size < resource->size)) ||
((last->align == resource->align) &&
(last->size == resource->size) &&
(!state->seen_last)))) {
return;
}
if (!state->result ||
(state->result->align < resource->align) ||
((state->result->align == resource->align) &&
(state->result->size < resource->size))) {
state->result_dev = dev;
state->result = resource;
}
}
static void find_largest_resource(struct pick_largest_state *state,
struct bus *bus, unsigned long type_mask, unsigned long type)
{
struct device *curdev;
for(curdev = bus->children; curdev; curdev = curdev->sibling) {
int i;
for(i = 0; i < curdev->resources; i++) {
struct resource *resource = &curdev->resource[i];
/* If it isn't the right kind of resource ignore it */
if ((resource->flags & type_mask) != type) {
continue;
}
/* If it is a subtractive resource recurse */
if (resource->flags & IORESOURCE_SUBTRACTIVE) {
struct bus *subbus;
subbus = &curdev->link[resource->index];
find_largest_resource(state, subbus, type_mask, type);
continue;
}
/* See if this is the largest resource */
pick_largest_resource(state, curdev, resource);
}
}
}
static struct device *largest_resource(struct bus *bus, struct resource **result_res,
unsigned long type_mask, unsigned long type)
{
struct pick_largest_state state;
state.last = *result_res;
state.result_dev = 0;
state.result = 0;
state.seen_last = 0;
find_largest_resource(&state, bus, type_mask, type);
*result_res = state.result;
return state.result_dev;
}
/* Compute allocate resources is the guts of the resource allocator.
*
* The problem.
* - Allocate resources 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 thier 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 me 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.
*
*/
void compute_allocate_resource(
struct bus *bus,
struct resource *bridge,
unsigned long type_mask,
unsigned long type)
{
struct device *dev;
struct resource *resource;
unsigned long base;
unsigned long align, min_align;
min_align = 0;
base = bridge->base;
/* We want different minimum alignments for different kinds of
* resources. These minimums are not device type specific
* but resource type specific.
*/
if (bridge->flags & IORESOURCE_IO) {
min_align = log2(DEVICE_IO_ALIGN);
}
if (bridge->flags & IORESOURCE_MEM) {
min_align = log2(DEVICE_MEM_ALIGN);
}
printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d\n",
dev_path(dev),
(bridge->flags & IORESOURCE_IO)? "io":
(bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
base, bridge->size, bridge->align, bridge->gran);
/* Make certain I have read in all of the resources */
read_resources(bus);
/* Remember I haven't found anything yet. */
resource = 0;
/* Walk through all the devices on the current bus and compute the addresses */
while((dev = largest_resource(bus, &resource, type_mask, type))) {
unsigned long size;
/* Do NOT I repeat do not ignore resources which have zero size.
* If they need to be ignored dev->read_resources should not even
* return them. Some resources must be set even when they have
* no size. PCI bridge resources are a good example of this.
*/
/* Propogate the resource alignment to the bridge register */
if (resource->align > bridge->align) {
bridge->align = resource->align;
}
/* Make certain we are dealing with a good minimum size */
size = resource->size;
align = resource->align;
if (align < min_align) {
align = min_align;
}
if (resource->flags & IORESOURCE_FIXED) {
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 100h - 3ffh. Therefor, only 0 - ff
* can be used out of each 400h block of io
* space.
*/
if ((base & 0x300) != 0) {
base = (base & ~0x3ff) + 0x400;
}
/* Don't allow allocations in the VGA IO range.
* PCI has special cases for that.
*/
else if ((base >= 0x3b0) && (base <= 0x3df)) {
base = 0x3e0;
}
}
if (((round(base, 1UL << align) + size) -1) <= resource->limit) {
/* base must be aligned to size */
base = round(base, 1UL << align);
resource->base = base;
resource->flags |= IORESOURCE_SET;
base += size;
printk_spew(
"%s %02x * [0x%08lx - 0x%08lx] %s\n",
dev_path(dev),
resource->index,
resource->base, resource->base + resource->size -1,
(resource->flags & IORESOURCE_IO)? "io":
(resource->flags & IORESOURCE_PREFETCH)? "prefmem": "mem");
}
}
/* 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 postitively
* decoded by the bridge.
*/
bridge->size = round(base, 1UL << bridge->gran) - bridge->base;
printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d done\n",
dev_path(dev),
(bridge->flags & IORESOURCE_IO)? "io":
(bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
base, bridge->size, bridge->align, bridge->gran);
}
static void allocate_vga_resource(void)
{
#warning "FIXME modify allocate_vga_resource so it is less pci centric!"
/* FIXME handle the VGA pallette snooping */
struct device *dev, *vga;
struct bus *bus;
bus = 0;
vga = 0;
for(dev = all_devices; dev; dev = dev->next) {
if (((dev->class >> 16) == 0x03) &&
((dev->class >> 8) != 0x380)) {
if (!vga) {
printk_debug("Allocating VGA resource\n");
vga = dev;
}
if (vga == dev) {
/* All legacy VGA cards have MEM & I/O space registers */
dev->command |= PCI_COMMAND_MEMORY | PCI_COMMAND_IO;
} else {
/* It isn't safe to enable other VGA cards */
dev->command &= ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
}
}
}
if (vga) {
bus = vga->bus;
}
/* Now walk up the bridges setting the VGA enable */
while(bus) {
bus->bridge_ctrl |= PCI_BRIDGE_CONTROL;
bus = (bus == bus->dev->bus)? 0 : bus->dev->bus;
}
}
/** Assign the computed resources to the bridges and devices on the bus.
* Recurse to any bridges found on this bus first. Then do the devices
* on this bus.
* @param bus Pointer to the structure for this bus
*/
void assign_resources(struct bus *bus)
{
struct device *curdev;
printk_debug("ASSIGN RESOURCES, bus %d\n", bus->secondary);
for (curdev = bus->children; curdev; curdev = curdev->sibling) {
if (!curdev->ops || !curdev->ops->set_resources) {
printk_err("%s missing set_resources\n",
dev_path(curdev));
continue;
}
curdev->ops->set_resources(curdev);
}
printk_debug("ASSIGNED RESOURCES, bus %d\n", bus->secondary);
}
void enable_resources(struct device *dev)
{
/* Enable the resources for a specific device.
* The parents resources should be enabled first to avoid
* having enabling ordering problems.
*/
if (!dev->ops || !dev->ops->enable_resources) {
printk_err("%s missing enable_resources\n",
dev_path(dev));
return;
}
dev->ops->enable_resources(dev);
}
/** Enumerate the resources on the PCI by calling pci_init
*/
void dev_enumerate(void)
{
struct device *root;
unsigned subordinate;
printk_info("Enumerating buses...");
root = &dev_root;
subordinate = root->ops->scan_bus(root, 0);
printk_info("done\n");
}
/** Starting at the root, compute what resources are needed and allocate them.
* I/O starts at PCI_IO_START. Since the assignment is hierarchical we
* set the values into the dev_root struct.
*/
void dev_configure(void)
{
struct device *root = &dev_root;
printk_info("Allocating resources...");
printk_debug("\n");
root->ops->read_resources(root);
/* Make certain the io devices are allocated somewhere
* safe.
*/
root->resource[0].base = DEVICE_IO_START;
root->resource[0].flags |= IORESOURCE_SET;
/* Now reallocate the pci resources memory with the
* highest addresses I can manage.
*/
root->resource[1].base =
round_down(DEVICE_MEM_HIGH - root->resource[1].size,
1UL << root->resource[1].align);
root->resource[1].flags |= IORESOURCE_SET;
// now just set things into registers ... we hope ...
root->ops->set_resources(root);
allocate_vga_resource();
printk_info("done.\n");
}
/** Starting at the root, walk the tree and enable all devices/bridges.
* What really happens is computed COMMAND bits get set in register 4
*/
void dev_enable(void)
{
printk_info("Enabling resourcess...\n");
/* now enable everything. */
enable_resources(&dev_root);
printk_info("done.\n");
}
/** Starting at the root, walk the tree and call a driver to
* do device specific setup.
*/
void dev_initialize(void)
{
struct device *dev;
printk_info("Initializing devices...\n");
for (dev = all_devices; dev; dev = dev->next) {
if (dev->ops && dev->ops->init) {
printk_debug("%s init\n", dev_path(dev));
dev->ops->init(dev);
}
}
printk_info("Devices initialized\n");
}