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linux/drivers/pci/setup-bus.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2 
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

552 lines
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/*
* drivers/pci/setup-bus.c
*
* Extruded from code written by
* Dave Rusling (david.rusling@reo.mts.dec.com)
* David Mosberger (davidm@cs.arizona.edu)
* David Miller (davem@redhat.com)
*
* Support routines for initializing a PCI subsystem.
*/
/*
* Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
* PCI-PCI bridges cleanup, sorted resource allocation.
* Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
* Converted to allocation in 3 passes, which gives
* tighter packing. Prefetchable range support.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include <linux/slab.h>
#define DEBUG_CONFIG 1
#if DEBUG_CONFIG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
#define ROUND_UP(x, a) (((x) + (a) - 1) & ~((a) - 1))
/*
* FIXME: IO should be max 256 bytes. However, since we may
* have a P2P bridge below a cardbus bridge, we need 4K.
*/
#define CARDBUS_IO_SIZE (4096)
#define CARDBUS_MEM_SIZE (32*1024*1024)
static void __devinit
pbus_assign_resources_sorted(struct pci_bus *bus)
{
struct pci_dev *dev;
struct resource *res;
struct resource_list head, *list, *tmp;
int idx;
bus->bridge_ctl &= ~PCI_BRIDGE_CTL_VGA;
head.next = NULL;
list_for_each_entry(dev, &bus->devices, bus_list) {
u16 class = dev->class >> 8;
/* Don't touch classless devices and host bridges. */
if (class == PCI_CLASS_NOT_DEFINED ||
class == PCI_CLASS_BRIDGE_HOST)
continue;
if (class == PCI_CLASS_DISPLAY_VGA ||
class == PCI_CLASS_NOT_DEFINED_VGA)
bus->bridge_ctl |= PCI_BRIDGE_CTL_VGA;
pdev_sort_resources(dev, &head);
}
for (list = head.next; list;) {
res = list->res;
idx = res - &list->dev->resource[0];
pci_assign_resource(list->dev, idx);
tmp = list;
list = list->next;
kfree(tmp);
}
}
static void __devinit
pci_setup_cardbus(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct pci_bus_region region;
printk("PCI: Bus %d, cardbus bridge: %s\n",
bus->number, pci_name(bridge));
pcibios_resource_to_bus(bridge, &region, bus->resource[0]);
if (bus->resource[0]->flags & IORESOURCE_IO) {
/*
* The IO resource is allocated a range twice as large as it
* would normally need. This allows us to set both IO regs.
*/
printk(" IO window: %08lx-%08lx\n",
region.start, region.end);
pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
region.start);
pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
region.end);
}
pcibios_resource_to_bus(bridge, &region, bus->resource[1]);
if (bus->resource[1]->flags & IORESOURCE_IO) {
printk(" IO window: %08lx-%08lx\n",
region.start, region.end);
pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
region.start);
pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
region.end);
}
pcibios_resource_to_bus(bridge, &region, bus->resource[2]);
if (bus->resource[2]->flags & IORESOURCE_MEM) {
printk(" PREFETCH window: %08lx-%08lx\n",
region.start, region.end);
pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
region.start);
pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
region.end);
}
pcibios_resource_to_bus(bridge, &region, bus->resource[3]);
if (bus->resource[3]->flags & IORESOURCE_MEM) {
printk(" MEM window: %08lx-%08lx\n",
region.start, region.end);
pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
region.start);
pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
region.end);
}
}
/* Initialize bridges with base/limit values we have collected.
PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
requires that if there is no I/O ports or memory behind the
bridge, corresponding range must be turned off by writing base
value greater than limit to the bridge's base/limit registers.
Note: care must be taken when updating I/O base/limit registers
of bridges which support 32-bit I/O. This update requires two
config space writes, so it's quite possible that an I/O window of
the bridge will have some undesirable address (e.g. 0) after the
first write. Ditto 64-bit prefetchable MMIO. */
static void __devinit
pci_setup_bridge(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct pci_bus_region region;
u32 l, io_upper16;
DBG(KERN_INFO "PCI: Bridge: %s\n", pci_name(bridge));
/* Set up the top and bottom of the PCI I/O segment for this bus. */
pcibios_resource_to_bus(bridge, &region, bus->resource[0]);
if (bus->resource[0]->flags & IORESOURCE_IO) {
pci_read_config_dword(bridge, PCI_IO_BASE, &l);
l &= 0xffff0000;
l |= (region.start >> 8) & 0x00f0;
l |= region.end & 0xf000;
/* Set up upper 16 bits of I/O base/limit. */
io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
DBG(KERN_INFO " IO window: %04lx-%04lx\n",
region.start, region.end);
}
else {
/* Clear upper 16 bits of I/O base/limit. */
io_upper16 = 0;
l = 0x00f0;
DBG(KERN_INFO " IO window: disabled.\n");
}
/* Temporarily disable the I/O range before updating PCI_IO_BASE. */
pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
/* Update lower 16 bits of I/O base/limit. */
pci_write_config_dword(bridge, PCI_IO_BASE, l);
/* Update upper 16 bits of I/O base/limit. */
pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
/* Set up the top and bottom of the PCI Memory segment
for this bus. */
pcibios_resource_to_bus(bridge, &region, bus->resource[1]);
if (bus->resource[1]->flags & IORESOURCE_MEM) {
l = (region.start >> 16) & 0xfff0;
l |= region.end & 0xfff00000;
DBG(KERN_INFO " MEM window: %08lx-%08lx\n",
region.start, region.end);
}
else {
l = 0x0000fff0;
DBG(KERN_INFO " MEM window: disabled.\n");
}
pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
/* Clear out the upper 32 bits of PREF limit.
If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
disables PREF range, which is ok. */
pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
/* Set up PREF base/limit. */
pcibios_resource_to_bus(bridge, &region, bus->resource[2]);
if (bus->resource[2]->flags & IORESOURCE_PREFETCH) {
l = (region.start >> 16) & 0xfff0;
l |= region.end & 0xfff00000;
DBG(KERN_INFO " PREFETCH window: %08lx-%08lx\n",
region.start, region.end);
}
else {
l = 0x0000fff0;
DBG(KERN_INFO " PREFETCH window: disabled.\n");
}
pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
/* Clear out the upper 32 bits of PREF base. */
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 0);
pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
}
/* Check whether the bridge supports optional I/O and
prefetchable memory ranges. If not, the respective
base/limit registers must be read-only and read as 0. */
static void __devinit
pci_bridge_check_ranges(struct pci_bus *bus)
{
u16 io;
u32 pmem;
struct pci_dev *bridge = bus->self;
struct resource *b_res;
b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
b_res[1].flags |= IORESOURCE_MEM;
pci_read_config_word(bridge, PCI_IO_BASE, &io);
if (!io) {
pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0);
pci_read_config_word(bridge, PCI_IO_BASE, &io);
pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
}
if (io)
b_res[0].flags |= IORESOURCE_IO;
/* DECchip 21050 pass 2 errata: the bridge may miss an address
disconnect boundary by one PCI data phase.
Workaround: do not use prefetching on this device. */
if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
return;
pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
if (!pmem) {
pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
0xfff0fff0);
pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
}
if (pmem)
b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
}
/* Helper function for sizing routines: find first available
bus resource of a given type. Note: we intentionally skip
the bus resources which have already been assigned (that is,
have non-NULL parent resource). */
static struct resource * __devinit
find_free_bus_resource(struct pci_bus *bus, unsigned long type)
{
int i;
struct resource *r;
unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
IORESOURCE_PREFETCH;
for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
r = bus->resource[i];
if (r && (r->flags & type_mask) == type && !r->parent)
return r;
}
return NULL;
}
/* Sizing the IO windows of the PCI-PCI bridge is trivial,
since these windows have 4K granularity and the IO ranges
of non-bridge PCI devices are limited to 256 bytes.
We must be careful with the ISA aliasing though. */
static void __devinit
pbus_size_io(struct pci_bus *bus)
{
struct pci_dev *dev;
struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
unsigned long size = 0, size1 = 0;
if (!b_res)
return;
list_for_each_entry(dev, &bus->devices, bus_list) {
int i;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *r = &dev->resource[i];
unsigned long r_size;
if (r->parent || !(r->flags & IORESOURCE_IO))
continue;
r_size = r->end - r->start + 1;
if (r_size < 0x400)
/* Might be re-aligned for ISA */
size += r_size;
else
size1 += r_size;
}
}
/* To be fixed in 2.5: we should have sort of HAVE_ISA
flag in the struct pci_bus. */
#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
size = (size & 0xff) + ((size & ~0xffUL) << 2);
#endif
size = ROUND_UP(size + size1, 4096);
if (!size) {
b_res->flags = 0;
return;
}
/* Alignment of the IO window is always 4K */
b_res->start = 4096;
b_res->end = b_res->start + size - 1;
}
/* Calculate the size of the bus and minimal alignment which
guarantees that all child resources fit in this size. */
static int __devinit
pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
{
struct pci_dev *dev;
unsigned long min_align, align, size;
unsigned long aligns[12]; /* Alignments from 1Mb to 2Gb */
int order, max_order;
struct resource *b_res = find_free_bus_resource(bus, type);
if (!b_res)
return 0;
memset(aligns, 0, sizeof(aligns));
max_order = 0;
size = 0;
list_for_each_entry(dev, &bus->devices, bus_list) {
int i;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *r = &dev->resource[i];
unsigned long r_size;
if (r->parent || (r->flags & mask) != type)
continue;
r_size = r->end - r->start + 1;
/* For bridges size != alignment */
align = (i < PCI_BRIDGE_RESOURCES) ? r_size : r->start;
order = __ffs(align) - 20;
if (order > 11) {
printk(KERN_WARNING "PCI: region %s/%d "
"too large: %lx-%lx\n",
pci_name(dev), i, r->start, r->end);
r->flags = 0;
continue;
}
size += r_size;
if (order < 0)
order = 0;
/* Exclude ranges with size > align from
calculation of the alignment. */
if (r_size == align)
aligns[order] += align;
if (order > max_order)
max_order = order;
}
}
align = 0;
min_align = 0;
for (order = 0; order <= max_order; order++) {
unsigned long align1 = 1UL << (order + 20);
if (!align)
min_align = align1;
else if (ROUND_UP(align + min_align, min_align) < align1)
min_align = align1 >> 1;
align += aligns[order];
}
size = ROUND_UP(size, min_align);
if (!size) {
b_res->flags = 0;
return 1;
}
b_res->start = min_align;
b_res->end = size + min_align - 1;
return 1;
}
static void __devinit
pci_bus_size_cardbus(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
u16 ctrl;
/*
* Reserve some resources for CardBus. We reserve
* a fixed amount of bus space for CardBus bridges.
*/
b_res[0].start = CARDBUS_IO_SIZE;
b_res[0].end = b_res[0].start + CARDBUS_IO_SIZE - 1;
b_res[0].flags |= IORESOURCE_IO;
b_res[1].start = CARDBUS_IO_SIZE;
b_res[1].end = b_res[1].start + CARDBUS_IO_SIZE - 1;
b_res[1].flags |= IORESOURCE_IO;
/*
* Check whether prefetchable memory is supported
* by this bridge.
*/
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
}
/*
* If we have prefetchable memory support, allocate
* two regions. Otherwise, allocate one region of
* twice the size.
*/
if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
b_res[2].start = CARDBUS_MEM_SIZE;
b_res[2].end = b_res[2].start + CARDBUS_MEM_SIZE - 1;
b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
b_res[3].start = CARDBUS_MEM_SIZE;
b_res[3].end = b_res[3].start + CARDBUS_MEM_SIZE - 1;
b_res[3].flags |= IORESOURCE_MEM;
} else {
b_res[3].start = CARDBUS_MEM_SIZE * 2;
b_res[3].end = b_res[3].start + CARDBUS_MEM_SIZE * 2 - 1;
b_res[3].flags |= IORESOURCE_MEM;
}
}
void __devinit
pci_bus_size_bridges(struct pci_bus *bus)
{
struct pci_dev *dev;
unsigned long mask, prefmask;
list_for_each_entry(dev, &bus->devices, bus_list) {
struct pci_bus *b = dev->subordinate;
if (!b)
continue;
switch (dev->class >> 8) {
case PCI_CLASS_BRIDGE_CARDBUS:
pci_bus_size_cardbus(b);
break;
case PCI_CLASS_BRIDGE_PCI:
default:
pci_bus_size_bridges(b);
break;
}
}
/* The root bus? */
if (!bus->self)
return;
switch (bus->self->class >> 8) {
case PCI_CLASS_BRIDGE_CARDBUS:
/* don't size cardbuses yet. */
break;
case PCI_CLASS_BRIDGE_PCI:
pci_bridge_check_ranges(bus);
default:
pbus_size_io(bus);
/* If the bridge supports prefetchable range, size it
separately. If it doesn't, or its prefetchable window
has already been allocated by arch code, try
non-prefetchable range for both types of PCI memory
resources. */
mask = IORESOURCE_MEM;
prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
if (pbus_size_mem(bus, prefmask, prefmask))
mask = prefmask; /* Success, size non-prefetch only. */
pbus_size_mem(bus, mask, IORESOURCE_MEM);
break;
}
}
EXPORT_SYMBOL(pci_bus_size_bridges);
void __devinit
pci_bus_assign_resources(struct pci_bus *bus)
{
struct pci_bus *b;
struct pci_dev *dev;
pbus_assign_resources_sorted(bus);
if (bus->bridge_ctl & PCI_BRIDGE_CTL_VGA) {
/* Propagate presence of the VGA to upstream bridges */
for (b = bus; b->parent; b = b->parent) {
b->bridge_ctl |= PCI_BRIDGE_CTL_VGA;
}
}
list_for_each_entry(dev, &bus->devices, bus_list) {
b = dev->subordinate;
if (!b)
continue;
pci_bus_assign_resources(b);
switch (dev->class >> 8) {
case PCI_CLASS_BRIDGE_PCI:
pci_setup_bridge(b);
break;
case PCI_CLASS_BRIDGE_CARDBUS:
pci_setup_cardbus(b);
break;
default:
printk(KERN_INFO "PCI: not setting up bridge %s "
"for bus %d\n", pci_name(dev), b->number);
break;
}
}
}
EXPORT_SYMBOL(pci_bus_assign_resources);
void __init
pci_assign_unassigned_resources(void)
{
struct pci_bus *bus;
/* Depth first, calculate sizes and alignments of all
subordinate buses. */
list_for_each_entry(bus, &pci_root_buses, node) {
pci_bus_size_bridges(bus);
}
/* Depth last, allocate resources and update the hardware. */
list_for_each_entry(bus, &pci_root_buses, node) {
pci_bus_assign_resources(bus);
pci_enable_bridges(bus);
}
}
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