linux/drivers/pci/probe.c
Jacob Pan 253d2e5498 PCI: disable mmio during bar sizing
It is a known issue that mmio decoding shall be disabled while doing PCI
bar sizing. Host bridge and other devices (PCI PIC) shall be excluded for
certain platforms. This patch mainly comes from Mathew Willcox's
patch in http://kerneltrap.org/mailarchive/linux-kernel/2007/9/13/258969.

A new flag bit "mmio_alway_on" is added to pci_dev with the intention that
devices with their mmio decoding cannot be disabled during BAR sizing shall
have this bit set, preferrablly in their quirks.

Without this patch, Intel Moorestown platform graphics unit will be
corrupted during bar sizing activities.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-07-30 09:29:35 -07:00

1555 lines
39 KiB
C

/*
* probe.c - PCI detection and setup code
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/cpumask.h>
#include <linux/pci-aspm.h>
#include "pci.h"
#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
#define CARDBUS_RESERVE_BUSNR 3
/* Ugh. Need to stop exporting this to modules. */
LIST_HEAD(pci_root_buses);
EXPORT_SYMBOL(pci_root_buses);
static int find_anything(struct device *dev, void *data)
{
return 1;
}
/*
* Some device drivers need know if pci is initiated.
* Basically, we think pci is not initiated when there
* is no device to be found on the pci_bus_type.
*/
int no_pci_devices(void)
{
struct device *dev;
int no_devices;
dev = bus_find_device(&pci_bus_type, NULL, NULL, find_anything);
no_devices = (dev == NULL);
put_device(dev);
return no_devices;
}
EXPORT_SYMBOL(no_pci_devices);
/*
* PCI Bus Class Devices
*/
static ssize_t pci_bus_show_cpuaffinity(struct device *dev,
int type,
struct device_attribute *attr,
char *buf)
{
int ret;
const struct cpumask *cpumask;
cpumask = cpumask_of_pcibus(to_pci_bus(dev));
ret = type?
cpulist_scnprintf(buf, PAGE_SIZE-2, cpumask) :
cpumask_scnprintf(buf, PAGE_SIZE-2, cpumask);
buf[ret++] = '\n';
buf[ret] = '\0';
return ret;
}
static ssize_t inline pci_bus_show_cpumaskaffinity(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return pci_bus_show_cpuaffinity(dev, 0, attr, buf);
}
static ssize_t inline pci_bus_show_cpulistaffinity(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return pci_bus_show_cpuaffinity(dev, 1, attr, buf);
}
DEVICE_ATTR(cpuaffinity, S_IRUGO, pci_bus_show_cpumaskaffinity, NULL);
DEVICE_ATTR(cpulistaffinity, S_IRUGO, pci_bus_show_cpulistaffinity, NULL);
/*
* PCI Bus Class
*/
static void release_pcibus_dev(struct device *dev)
{
struct pci_bus *pci_bus = to_pci_bus(dev);
if (pci_bus->bridge)
put_device(pci_bus->bridge);
pci_bus_remove_resources(pci_bus);
kfree(pci_bus);
}
static struct class pcibus_class = {
.name = "pci_bus",
.dev_release = &release_pcibus_dev,
};
static int __init pcibus_class_init(void)
{
return class_register(&pcibus_class);
}
postcore_initcall(pcibus_class_init);
/*
* Translate the low bits of the PCI base
* to the resource type
*/
static inline unsigned int pci_calc_resource_flags(unsigned int flags)
{
if (flags & PCI_BASE_ADDRESS_SPACE_IO)
return IORESOURCE_IO;
if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
return IORESOURCE_MEM | IORESOURCE_PREFETCH;
return IORESOURCE_MEM;
}
static u64 pci_size(u64 base, u64 maxbase, u64 mask)
{
u64 size = mask & maxbase; /* Find the significant bits */
if (!size)
return 0;
/* Get the lowest of them to find the decode size, and
from that the extent. */
size = (size & ~(size-1)) - 1;
/* base == maxbase can be valid only if the BAR has
already been programmed with all 1s. */
if (base == maxbase && ((base | size) & mask) != mask)
return 0;
return size;
}
static inline enum pci_bar_type decode_bar(struct resource *res, u32 bar)
{
if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
res->flags = bar & ~PCI_BASE_ADDRESS_IO_MASK;
return pci_bar_io;
}
res->flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK;
if (res->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)
return pci_bar_mem64;
return pci_bar_mem32;
}
/**
* pci_read_base - read a PCI BAR
* @dev: the PCI device
* @type: type of the BAR
* @res: resource buffer to be filled in
* @pos: BAR position in the config space
*
* Returns 1 if the BAR is 64-bit, or 0 if 32-bit.
*/
int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
struct resource *res, unsigned int pos)
{
u32 l, sz, mask;
u16 orig_cmd;
mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
if (!dev->mmio_always_on) {
pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
pci_write_config_word(dev, PCI_COMMAND,
orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
}
res->name = pci_name(dev);
pci_read_config_dword(dev, pos, &l);
pci_write_config_dword(dev, pos, l | mask);
pci_read_config_dword(dev, pos, &sz);
pci_write_config_dword(dev, pos, l);
if (!dev->mmio_always_on)
pci_write_config_word(dev, PCI_COMMAND, orig_cmd);
/*
* All bits set in sz means the device isn't working properly.
* If the BAR isn't implemented, all bits must be 0. If it's a
* memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit
* 1 must be clear.
*/
if (!sz || sz == 0xffffffff)
goto fail;
/*
* I don't know how l can have all bits set. Copied from old code.
* Maybe it fixes a bug on some ancient platform.
*/
if (l == 0xffffffff)
l = 0;
if (type == pci_bar_unknown) {
type = decode_bar(res, l);
res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN;
if (type == pci_bar_io) {
l &= PCI_BASE_ADDRESS_IO_MASK;
mask = PCI_BASE_ADDRESS_IO_MASK & IO_SPACE_LIMIT;
} else {
l &= PCI_BASE_ADDRESS_MEM_MASK;
mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
}
} else {
res->flags |= (l & IORESOURCE_ROM_ENABLE);
l &= PCI_ROM_ADDRESS_MASK;
mask = (u32)PCI_ROM_ADDRESS_MASK;
}
if (type == pci_bar_mem64) {
u64 l64 = l;
u64 sz64 = sz;
u64 mask64 = mask | (u64)~0 << 32;
pci_read_config_dword(dev, pos + 4, &l);
pci_write_config_dword(dev, pos + 4, ~0);
pci_read_config_dword(dev, pos + 4, &sz);
pci_write_config_dword(dev, pos + 4, l);
l64 |= ((u64)l << 32);
sz64 |= ((u64)sz << 32);
sz64 = pci_size(l64, sz64, mask64);
if (!sz64)
goto fail;
if ((sizeof(resource_size_t) < 8) && (sz64 > 0x100000000ULL)) {
dev_err(&dev->dev, "reg %x: can't handle 64-bit BAR\n",
pos);
goto fail;
}
res->flags |= IORESOURCE_MEM_64;
if ((sizeof(resource_size_t) < 8) && l) {
/* Address above 32-bit boundary; disable the BAR */
pci_write_config_dword(dev, pos, 0);
pci_write_config_dword(dev, pos + 4, 0);
res->start = 0;
res->end = sz64;
} else {
res->start = l64;
res->end = l64 + sz64;
dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n",
pos, res);
}
} else {
sz = pci_size(l, sz, mask);
if (!sz)
goto fail;
res->start = l;
res->end = l + sz;
dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n", pos, res);
}
out:
return (type == pci_bar_mem64) ? 1 : 0;
fail:
res->flags = 0;
goto out;
}
static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
{
unsigned int pos, reg;
for (pos = 0; pos < howmany; pos++) {
struct resource *res = &dev->resource[pos];
reg = PCI_BASE_ADDRESS_0 + (pos << 2);
pos += __pci_read_base(dev, pci_bar_unknown, res, reg);
}
if (rom) {
struct resource *res = &dev->resource[PCI_ROM_RESOURCE];
dev->rom_base_reg = rom;
res->flags = IORESOURCE_MEM | IORESOURCE_PREFETCH |
IORESOURCE_READONLY | IORESOURCE_CACHEABLE |
IORESOURCE_SIZEALIGN;
__pci_read_base(dev, pci_bar_mem32, res, rom);
}
}
static void __devinit pci_read_bridge_io(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
u8 io_base_lo, io_limit_lo;
unsigned long base, limit;
struct resource *res;
res = child->resource[0];
pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
base = (io_base_lo & PCI_IO_RANGE_MASK) << 8;
limit = (io_limit_lo & PCI_IO_RANGE_MASK) << 8;
if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
u16 io_base_hi, io_limit_hi;
pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi);
pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi);
base |= (io_base_hi << 16);
limit |= (io_limit_hi << 16);
}
if (base && base <= limit) {
res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
if (!res->start)
res->start = base;
if (!res->end)
res->end = limit + 0xfff;
dev_printk(KERN_DEBUG, &dev->dev, " bridge window %pR\n", res);
} else {
dev_printk(KERN_DEBUG, &dev->dev,
" bridge window [io %#06lx-%#06lx] (disabled)\n",
base, limit);
}
}
static void __devinit pci_read_bridge_mmio(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
u16 mem_base_lo, mem_limit_lo;
unsigned long base, limit;
struct resource *res;
res = child->resource[1];
pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo);
pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
base = (mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
limit = (mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
if (base && base <= limit) {
res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
res->start = base;
res->end = limit + 0xfffff;
dev_printk(KERN_DEBUG, &dev->dev, " bridge window %pR\n", res);
} else {
dev_printk(KERN_DEBUG, &dev->dev,
" bridge window [mem %#010lx-%#010lx] (disabled)\n",
base, limit + 0xfffff);
}
}
static void __devinit pci_read_bridge_mmio_pref(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
u16 mem_base_lo, mem_limit_lo;
unsigned long base, limit;
struct resource *res;
res = child->resource[2];
pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
base = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
limit = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16;
if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
u32 mem_base_hi, mem_limit_hi;
pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi);
pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi);
/*
* Some bridges set the base > limit by default, and some
* (broken) BIOSes do not initialize them. If we find
* this, just assume they are not being used.
*/
if (mem_base_hi <= mem_limit_hi) {
#if BITS_PER_LONG == 64
base |= ((long) mem_base_hi) << 32;
limit |= ((long) mem_limit_hi) << 32;
#else
if (mem_base_hi || mem_limit_hi) {
dev_err(&dev->dev, "can't handle 64-bit "
"address space for bridge\n");
return;
}
#endif
}
}
if (base && base <= limit) {
res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) |
IORESOURCE_MEM | IORESOURCE_PREFETCH;
if (res->flags & PCI_PREF_RANGE_TYPE_64)
res->flags |= IORESOURCE_MEM_64;
res->start = base;
res->end = limit + 0xfffff;
dev_printk(KERN_DEBUG, &dev->dev, " bridge window %pR\n", res);
} else {
dev_printk(KERN_DEBUG, &dev->dev,
" bridge window [mem %#010lx-%#010lx pref] (disabled)\n",
base, limit + 0xfffff);
}
}
void __devinit pci_read_bridge_bases(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
struct resource *res;
int i;
if (pci_is_root_bus(child)) /* It's a host bus, nothing to read */
return;
dev_info(&dev->dev, "PCI bridge to [bus %02x-%02x]%s\n",
child->secondary, child->subordinate,
dev->transparent ? " (subtractive decode)" : "");
pci_bus_remove_resources(child);
for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];
pci_read_bridge_io(child);
pci_read_bridge_mmio(child);
pci_read_bridge_mmio_pref(child);
if (dev->transparent) {
pci_bus_for_each_resource(child->parent, res, i) {
if (res) {
pci_bus_add_resource(child, res,
PCI_SUBTRACTIVE_DECODE);
dev_printk(KERN_DEBUG, &dev->dev,
" bridge window %pR (subtractive decode)\n",
res);
}
}
}
}
static struct pci_bus * pci_alloc_bus(void)
{
struct pci_bus *b;
b = kzalloc(sizeof(*b), GFP_KERNEL);
if (b) {
INIT_LIST_HEAD(&b->node);
INIT_LIST_HEAD(&b->children);
INIT_LIST_HEAD(&b->devices);
INIT_LIST_HEAD(&b->slots);
INIT_LIST_HEAD(&b->resources);
b->max_bus_speed = PCI_SPEED_UNKNOWN;
b->cur_bus_speed = PCI_SPEED_UNKNOWN;
}
return b;
}
static unsigned char pcix_bus_speed[] = {
PCI_SPEED_UNKNOWN, /* 0 */
PCI_SPEED_66MHz_PCIX, /* 1 */
PCI_SPEED_100MHz_PCIX, /* 2 */
PCI_SPEED_133MHz_PCIX, /* 3 */
PCI_SPEED_UNKNOWN, /* 4 */
PCI_SPEED_66MHz_PCIX_ECC, /* 5 */
PCI_SPEED_100MHz_PCIX_ECC, /* 6 */
PCI_SPEED_133MHz_PCIX_ECC, /* 7 */
PCI_SPEED_UNKNOWN, /* 8 */
PCI_SPEED_66MHz_PCIX_266, /* 9 */
PCI_SPEED_100MHz_PCIX_266, /* A */
PCI_SPEED_133MHz_PCIX_266, /* B */
PCI_SPEED_UNKNOWN, /* C */
PCI_SPEED_66MHz_PCIX_533, /* D */
PCI_SPEED_100MHz_PCIX_533, /* E */
PCI_SPEED_133MHz_PCIX_533 /* F */
};
static unsigned char pcie_link_speed[] = {
PCI_SPEED_UNKNOWN, /* 0 */
PCIE_SPEED_2_5GT, /* 1 */
PCIE_SPEED_5_0GT, /* 2 */
PCIE_SPEED_8_0GT, /* 3 */
PCI_SPEED_UNKNOWN, /* 4 */
PCI_SPEED_UNKNOWN, /* 5 */
PCI_SPEED_UNKNOWN, /* 6 */
PCI_SPEED_UNKNOWN, /* 7 */
PCI_SPEED_UNKNOWN, /* 8 */
PCI_SPEED_UNKNOWN, /* 9 */
PCI_SPEED_UNKNOWN, /* A */
PCI_SPEED_UNKNOWN, /* B */
PCI_SPEED_UNKNOWN, /* C */
PCI_SPEED_UNKNOWN, /* D */
PCI_SPEED_UNKNOWN, /* E */
PCI_SPEED_UNKNOWN /* F */
};
void pcie_update_link_speed(struct pci_bus *bus, u16 linksta)
{
bus->cur_bus_speed = pcie_link_speed[linksta & 0xf];
}
EXPORT_SYMBOL_GPL(pcie_update_link_speed);
static unsigned char agp_speeds[] = {
AGP_UNKNOWN,
AGP_1X,
AGP_2X,
AGP_4X,
AGP_8X
};
static enum pci_bus_speed agp_speed(int agp3, int agpstat)
{
int index = 0;
if (agpstat & 4)
index = 3;
else if (agpstat & 2)
index = 2;
else if (agpstat & 1)
index = 1;
else
goto out;
if (agp3) {
index += 2;
if (index == 5)
index = 0;
}
out:
return agp_speeds[index];
}
static void pci_set_bus_speed(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
int pos;
pos = pci_find_capability(bridge, PCI_CAP_ID_AGP);
if (!pos)
pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3);
if (pos) {
u32 agpstat, agpcmd;
pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat);
bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7);
pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd);
bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7);
}
pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
if (pos) {
u16 status;
enum pci_bus_speed max;
pci_read_config_word(bridge, pos + 2, &status);
if (status & 0x8000) {
max = PCI_SPEED_133MHz_PCIX_533;
} else if (status & 0x4000) {
max = PCI_SPEED_133MHz_PCIX_266;
} else if (status & 0x0002) {
if (((status >> 12) & 0x3) == 2) {
max = PCI_SPEED_133MHz_PCIX_ECC;
} else {
max = PCI_SPEED_133MHz_PCIX;
}
} else {
max = PCI_SPEED_66MHz_PCIX;
}
bus->max_bus_speed = max;
bus->cur_bus_speed = pcix_bus_speed[(status >> 6) & 0xf];
return;
}
pos = pci_find_capability(bridge, PCI_CAP_ID_EXP);
if (pos) {
u32 linkcap;
u16 linksta;
pci_read_config_dword(bridge, pos + PCI_EXP_LNKCAP, &linkcap);
bus->max_bus_speed = pcie_link_speed[linkcap & 0xf];
pci_read_config_word(bridge, pos + PCI_EXP_LNKSTA, &linksta);
pcie_update_link_speed(bus, linksta);
}
}
static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
struct pci_dev *bridge, int busnr)
{
struct pci_bus *child;
int i;
/*
* Allocate a new bus, and inherit stuff from the parent..
*/
child = pci_alloc_bus();
if (!child)
return NULL;
child->parent = parent;
child->ops = parent->ops;
child->sysdata = parent->sysdata;
child->bus_flags = parent->bus_flags;
/* initialize some portions of the bus device, but don't register it
* now as the parent is not properly set up yet. This device will get
* registered later in pci_bus_add_devices()
*/
child->dev.class = &pcibus_class;
dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr);
/*
* Set up the primary, secondary and subordinate
* bus numbers.
*/
child->number = child->secondary = busnr;
child->primary = parent->secondary;
child->subordinate = 0xff;
if (!bridge)
return child;
child->self = bridge;
child->bridge = get_device(&bridge->dev);
pci_set_bus_speed(child);
/* Set up default resource pointers and names.. */
for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {
child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
child->resource[i]->name = child->name;
}
bridge->subordinate = child;
return child;
}
struct pci_bus *__ref pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, int busnr)
{
struct pci_bus *child;
child = pci_alloc_child_bus(parent, dev, busnr);
if (child) {
down_write(&pci_bus_sem);
list_add_tail(&child->node, &parent->children);
up_write(&pci_bus_sem);
}
return child;
}
static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
{
struct pci_bus *parent = child->parent;
/* Attempts to fix that up are really dangerous unless
we're going to re-assign all bus numbers. */
if (!pcibios_assign_all_busses())
return;
while (parent->parent && parent->subordinate < max) {
parent->subordinate = max;
pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, max);
parent = parent->parent;
}
}
/*
* If it's a bridge, configure it and scan the bus behind it.
* For CardBus bridges, we don't scan behind as the devices will
* be handled by the bridge driver itself.
*
* We need to process bridges in two passes -- first we scan those
* already configured by the BIOS and after we are done with all of
* them, we proceed to assigning numbers to the remaining buses in
* order to avoid overlaps between old and new bus numbers.
*/
int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
{
struct pci_bus *child;
int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
u32 buses, i, j = 0;
u16 bctl;
u8 primary, secondary, subordinate;
int broken = 0;
pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
primary = buses & 0xFF;
secondary = (buses >> 8) & 0xFF;
subordinate = (buses >> 16) & 0xFF;
dev_dbg(&dev->dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
secondary, subordinate, pass);
/* Check if setup is sensible at all */
if (!pass &&
(primary != bus->number || secondary <= bus->number)) {
dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n");
broken = 1;
}
/* Disable MasterAbortMode during probing to avoid reporting
of bus errors (in some architectures) */
pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
!is_cardbus && !broken) {
unsigned int cmax;
/*
* Bus already configured by firmware, process it in the first
* pass and just note the configuration.
*/
if (pass)
goto out;
/*
* If we already got to this bus through a different bridge,
* don't re-add it. This can happen with the i450NX chipset.
*
* However, we continue to descend down the hierarchy and
* scan remaining child buses.
*/
child = pci_find_bus(pci_domain_nr(bus), secondary);
if (!child) {
child = pci_add_new_bus(bus, dev, secondary);
if (!child)
goto out;
child->primary = primary;
child->subordinate = subordinate;
child->bridge_ctl = bctl;
}
cmax = pci_scan_child_bus(child);
if (cmax > max)
max = cmax;
if (child->subordinate > max)
max = child->subordinate;
} else {
/*
* We need to assign a number to this bus which we always
* do in the second pass.
*/
if (!pass) {
if (pcibios_assign_all_busses() || broken)
/* Temporarily disable forwarding of the
configuration cycles on all bridges in
this bus segment to avoid possible
conflicts in the second pass between two
bridges programmed with overlapping
bus ranges. */
pci_write_config_dword(dev, PCI_PRIMARY_BUS,
buses & ~0xffffff);
goto out;
}
/* Clear errors */
pci_write_config_word(dev, PCI_STATUS, 0xffff);
/* Prevent assigning a bus number that already exists.
* This can happen when a bridge is hot-plugged */
if (pci_find_bus(pci_domain_nr(bus), max+1))
goto out;
child = pci_add_new_bus(bus, dev, ++max);
buses = (buses & 0xff000000)
| ((unsigned int)(child->primary) << 0)
| ((unsigned int)(child->secondary) << 8)
| ((unsigned int)(child->subordinate) << 16);
/*
* yenta.c forces a secondary latency timer of 176.
* Copy that behaviour here.
*/
if (is_cardbus) {
buses &= ~0xff000000;
buses |= CARDBUS_LATENCY_TIMER << 24;
}
/*
* We need to blast all three values with a single write.
*/
pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses);
if (!is_cardbus) {
child->bridge_ctl = bctl;
/*
* Adjust subordinate busnr in parent buses.
* We do this before scanning for children because
* some devices may not be detected if the bios
* was lazy.
*/
pci_fixup_parent_subordinate_busnr(child, max);
/* Now we can scan all subordinate buses... */
max = pci_scan_child_bus(child);
/*
* now fix it up again since we have found
* the real value of max.
*/
pci_fixup_parent_subordinate_busnr(child, max);
} else {
/*
* For CardBus bridges, we leave 4 bus numbers
* as cards with a PCI-to-PCI bridge can be
* inserted later.
*/
for (i=0; i<CARDBUS_RESERVE_BUSNR; i++) {
struct pci_bus *parent = bus;
if (pci_find_bus(pci_domain_nr(bus),
max+i+1))
break;
while (parent->parent) {
if ((!pcibios_assign_all_busses()) &&
(parent->subordinate > max) &&
(parent->subordinate <= max+i)) {
j = 1;
}
parent = parent->parent;
}
if (j) {
/*
* Often, there are two cardbus bridges
* -- try to leave one valid bus number
* for each one.
*/
i /= 2;
break;
}
}
max += i;
pci_fixup_parent_subordinate_busnr(child, max);
}
/*
* Set the subordinate bus number to its real value.
*/
child->subordinate = max;
pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
}
sprintf(child->name,
(is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
pci_domain_nr(bus), child->number);
/* Has only triggered on CardBus, fixup is in yenta_socket */
while (bus->parent) {
if ((child->subordinate > bus->subordinate) ||
(child->number > bus->subordinate) ||
(child->number < bus->number) ||
(child->subordinate < bus->number)) {
dev_info(&child->dev, "[bus %02x-%02x] %s "
"hidden behind%s bridge %s [bus %02x-%02x]\n",
child->number, child->subordinate,
(bus->number > child->subordinate &&
bus->subordinate < child->number) ?
"wholly" : "partially",
bus->self->transparent ? " transparent" : "",
dev_name(&bus->dev),
bus->number, bus->subordinate);
}
bus = bus->parent;
}
out:
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);
return max;
}
/*
* Read interrupt line and base address registers.
* The architecture-dependent code can tweak these, of course.
*/
static void pci_read_irq(struct pci_dev *dev)
{
unsigned char irq;
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
dev->pin = irq;
if (irq)
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
dev->irq = irq;
}
void set_pcie_port_type(struct pci_dev *pdev)
{
int pos;
u16 reg16;
pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
if (!pos)
return;
pdev->is_pcie = 1;
pdev->pcie_cap = pos;
pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
}
void set_pcie_hotplug_bridge(struct pci_dev *pdev)
{
int pos;
u16 reg16;
u32 reg32;
pos = pci_pcie_cap(pdev);
if (!pos)
return;
pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
if (!(reg16 & PCI_EXP_FLAGS_SLOT))
return;
pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &reg32);
if (reg32 & PCI_EXP_SLTCAP_HPC)
pdev->is_hotplug_bridge = 1;
}
#define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
/**
* pci_setup_device - fill in class and map information of a device
* @dev: the device structure to fill
*
* Initialize the device structure with information about the device's
* vendor,class,memory and IO-space addresses,IRQ lines etc.
* Called at initialisation of the PCI subsystem and by CardBus services.
* Returns 0 on success and negative if unknown type of device (not normal,
* bridge or CardBus).
*/
int pci_setup_device(struct pci_dev *dev)
{
u32 class;
u8 hdr_type;
struct pci_slot *slot;
int pos = 0;
if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
return -EIO;
dev->sysdata = dev->bus->sysdata;
dev->dev.parent = dev->bus->bridge;
dev->dev.bus = &pci_bus_type;
dev->hdr_type = hdr_type & 0x7f;
dev->multifunction = !!(hdr_type & 0x80);
dev->error_state = pci_channel_io_normal;
set_pcie_port_type(dev);
list_for_each_entry(slot, &dev->bus->slots, list)
if (PCI_SLOT(dev->devfn) == slot->number)
dev->slot = slot;
/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
set this higher, assuming the system even supports it. */
dev->dma_mask = 0xffffffff;
dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus),
dev->bus->number, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn));
pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
dev->revision = class & 0xff;
class >>= 8; /* upper 3 bytes */
dev->class = class;
class >>= 8;
dev_dbg(&dev->dev, "found [%04x:%04x] class %06x header type %02x\n",
dev->vendor, dev->device, class, dev->hdr_type);
/* need to have dev->class ready */
dev->cfg_size = pci_cfg_space_size(dev);
/* "Unknown power state" */
dev->current_state = PCI_UNKNOWN;
/* Early fixups, before probing the BARs */
pci_fixup_device(pci_fixup_early, dev);
/* device class may be changed after fixup */
class = dev->class >> 8;
switch (dev->hdr_type) { /* header type */
case PCI_HEADER_TYPE_NORMAL: /* standard header */
if (class == PCI_CLASS_BRIDGE_PCI)
goto bad;
pci_read_irq(dev);
pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);
/*
* Do the ugly legacy mode stuff here rather than broken chip
* quirk code. Legacy mode ATA controllers have fixed
* addresses. These are not always echoed in BAR0-3, and
* BAR0-3 in a few cases contain junk!
*/
if (class == PCI_CLASS_STORAGE_IDE) {
u8 progif;
pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
if ((progif & 1) == 0) {
dev->resource[0].start = 0x1F0;
dev->resource[0].end = 0x1F7;
dev->resource[0].flags = LEGACY_IO_RESOURCE;
dev->resource[1].start = 0x3F6;
dev->resource[1].end = 0x3F6;
dev->resource[1].flags = LEGACY_IO_RESOURCE;
}
if ((progif & 4) == 0) {
dev->resource[2].start = 0x170;
dev->resource[2].end = 0x177;
dev->resource[2].flags = LEGACY_IO_RESOURCE;
dev->resource[3].start = 0x376;
dev->resource[3].end = 0x376;
dev->resource[3].flags = LEGACY_IO_RESOURCE;
}
}
break;
case PCI_HEADER_TYPE_BRIDGE: /* bridge header */
if (class != PCI_CLASS_BRIDGE_PCI)
goto bad;
/* The PCI-to-PCI bridge spec requires that subtractive
decoding (i.e. transparent) bridge must have programming
interface code of 0x01. */
pci_read_irq(dev);
dev->transparent = ((dev->class & 0xff) == 1);
pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
set_pcie_hotplug_bridge(dev);
pos = pci_find_capability(dev, PCI_CAP_ID_SSVID);
if (pos) {
pci_read_config_word(dev, pos + PCI_SSVID_VENDOR_ID, &dev->subsystem_vendor);
pci_read_config_word(dev, pos + PCI_SSVID_DEVICE_ID, &dev->subsystem_device);
}
break;
case PCI_HEADER_TYPE_CARDBUS: /* CardBus bridge header */
if (class != PCI_CLASS_BRIDGE_CARDBUS)
goto bad;
pci_read_irq(dev);
pci_read_bases(dev, 1, 0);
pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device);
break;
default: /* unknown header */
dev_err(&dev->dev, "unknown header type %02x, "
"ignoring device\n", dev->hdr_type);
return -EIO;
bad:
dev_err(&dev->dev, "ignoring class %02x (doesn't match header "
"type %02x)\n", class, dev->hdr_type);
dev->class = PCI_CLASS_NOT_DEFINED;
}
/* We found a fine healthy device, go go go... */
return 0;
}
static void pci_release_capabilities(struct pci_dev *dev)
{
pci_vpd_release(dev);
pci_iov_release(dev);
}
/**
* pci_release_dev - free a pci device structure when all users of it are finished.
* @dev: device that's been disconnected
*
* Will be called only by the device core when all users of this pci device are
* done.
*/
static void pci_release_dev(struct device *dev)
{
struct pci_dev *pci_dev;
pci_dev = to_pci_dev(dev);
pci_release_capabilities(pci_dev);
kfree(pci_dev);
}
/**
* pci_cfg_space_size - get the configuration space size of the PCI device.
* @dev: PCI device
*
* Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
* have 4096 bytes. Even if the device is capable, that doesn't mean we can
* access it. Maybe we don't have a way to generate extended config space
* accesses, or the device is behind a reverse Express bridge. So we try
* reading the dword at 0x100 which must either be 0 or a valid extended
* capability header.
*/
int pci_cfg_space_size_ext(struct pci_dev *dev)
{
u32 status;
int pos = PCI_CFG_SPACE_SIZE;
if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL)
goto fail;
if (status == 0xffffffff)
goto fail;
return PCI_CFG_SPACE_EXP_SIZE;
fail:
return PCI_CFG_SPACE_SIZE;
}
int pci_cfg_space_size(struct pci_dev *dev)
{
int pos;
u32 status;
u16 class;
class = dev->class >> 8;
if (class == PCI_CLASS_BRIDGE_HOST)
return pci_cfg_space_size_ext(dev);
pos = pci_pcie_cap(dev);
if (!pos) {
pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!pos)
goto fail;
pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
if (!(status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)))
goto fail;
}
return pci_cfg_space_size_ext(dev);
fail:
return PCI_CFG_SPACE_SIZE;
}
static void pci_release_bus_bridge_dev(struct device *dev)
{
kfree(dev);
}
struct pci_dev *alloc_pci_dev(void)
{
struct pci_dev *dev;
dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
if (!dev)
return NULL;
INIT_LIST_HEAD(&dev->bus_list);
return dev;
}
EXPORT_SYMBOL(alloc_pci_dev);
/*
* Read the config data for a PCI device, sanity-check it
* and fill in the dev structure...
*/
static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
{
struct pci_dev *dev;
u32 l;
int delay = 1;
if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
return NULL;
/* some broken boards return 0 or ~0 if a slot is empty: */
if (l == 0xffffffff || l == 0x00000000 ||
l == 0x0000ffff || l == 0xffff0000)
return NULL;
/* Configuration request Retry Status */
while (l == 0xffff0001) {
msleep(delay);
delay *= 2;
if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
return NULL;
/* Card hasn't responded in 60 seconds? Must be stuck. */
if (delay > 60 * 1000) {
printk(KERN_WARNING "pci %04x:%02x:%02x.%d: not "
"responding\n", pci_domain_nr(bus),
bus->number, PCI_SLOT(devfn),
PCI_FUNC(devfn));
return NULL;
}
}
dev = alloc_pci_dev();
if (!dev)
return NULL;
dev->bus = bus;
dev->devfn = devfn;
dev->vendor = l & 0xffff;
dev->device = (l >> 16) & 0xffff;
if (pci_setup_device(dev)) {
kfree(dev);
return NULL;
}
return dev;
}
static void pci_init_capabilities(struct pci_dev *dev)
{
/* MSI/MSI-X list */
pci_msi_init_pci_dev(dev);
/* Buffers for saving PCIe and PCI-X capabilities */
pci_allocate_cap_save_buffers(dev);
/* Power Management */
pci_pm_init(dev);
platform_pci_wakeup_init(dev);
/* Vital Product Data */
pci_vpd_pci22_init(dev);
/* Alternative Routing-ID Forwarding */
pci_enable_ari(dev);
/* Single Root I/O Virtualization */
pci_iov_init(dev);
/* Enable ACS P2P upstream forwarding */
pci_enable_acs(dev);
}
void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
{
device_initialize(&dev->dev);
dev->dev.release = pci_release_dev;
pci_dev_get(dev);
dev->dev.dma_mask = &dev->dma_mask;
dev->dev.dma_parms = &dev->dma_parms;
dev->dev.coherent_dma_mask = 0xffffffffull;
pci_set_dma_max_seg_size(dev, 65536);
pci_set_dma_seg_boundary(dev, 0xffffffff);
/* Fix up broken headers */
pci_fixup_device(pci_fixup_header, dev);
/* Clear the state_saved flag. */
dev->state_saved = false;
/* Initialize various capabilities */
pci_init_capabilities(dev);
/*
* Add the device to our list of discovered devices
* and the bus list for fixup functions, etc.
*/
down_write(&pci_bus_sem);
list_add_tail(&dev->bus_list, &bus->devices);
up_write(&pci_bus_sem);
}
struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
{
struct pci_dev *dev;
dev = pci_get_slot(bus, devfn);
if (dev) {
pci_dev_put(dev);
return dev;
}
dev = pci_scan_device(bus, devfn);
if (!dev)
return NULL;
pci_device_add(dev, bus);
return dev;
}
EXPORT_SYMBOL(pci_scan_single_device);
static unsigned next_ari_fn(struct pci_dev *dev, unsigned fn)
{
u16 cap;
unsigned pos, next_fn;
if (!dev)
return 0;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
if (!pos)
return 0;
pci_read_config_word(dev, pos + 4, &cap);
next_fn = cap >> 8;
if (next_fn <= fn)
return 0;
return next_fn;
}
static unsigned next_trad_fn(struct pci_dev *dev, unsigned fn)
{
return (fn + 1) % 8;
}
static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
{
return 0;
}
static int only_one_child(struct pci_bus *bus)
{
struct pci_dev *parent = bus->self;
if (!parent || !pci_is_pcie(parent))
return 0;
if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
return 1;
return 0;
}
/**
* pci_scan_slot - scan a PCI slot on a bus for devices.
* @bus: PCI bus to scan
* @devfn: slot number to scan (must have zero function.)
*
* Scan a PCI slot on the specified PCI bus for devices, adding
* discovered devices to the @bus->devices list. New devices
* will not have is_added set.
*
* Returns the number of new devices found.
*/
int pci_scan_slot(struct pci_bus *bus, int devfn)
{
unsigned fn, nr = 0;
struct pci_dev *dev;
unsigned (*next_fn)(struct pci_dev *, unsigned) = no_next_fn;
if (only_one_child(bus) && (devfn > 0))
return 0; /* Already scanned the entire slot */
dev = pci_scan_single_device(bus, devfn);
if (!dev)
return 0;
if (!dev->is_added)
nr++;
if (pci_ari_enabled(bus))
next_fn = next_ari_fn;
else if (dev->multifunction)
next_fn = next_trad_fn;
for (fn = next_fn(dev, 0); fn > 0; fn = next_fn(dev, fn)) {
dev = pci_scan_single_device(bus, devfn + fn);
if (dev) {
if (!dev->is_added)
nr++;
dev->multifunction = 1;
}
}
/* only one slot has pcie device */
if (bus->self && nr)
pcie_aspm_init_link_state(bus->self);
return nr;
}
unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
{
unsigned int devfn, pass, max = bus->secondary;
struct pci_dev *dev;
dev_dbg(&bus->dev, "scanning bus\n");
/* Go find them, Rover! */
for (devfn = 0; devfn < 0x100; devfn += 8)
pci_scan_slot(bus, devfn);
/* Reserve buses for SR-IOV capability. */
max += pci_iov_bus_range(bus);
/*
* After performing arch-dependent fixup of the bus, look behind
* all PCI-to-PCI bridges on this bus.
*/
if (!bus->is_added) {
dev_dbg(&bus->dev, "fixups for bus\n");
pcibios_fixup_bus(bus);
if (pci_is_root_bus(bus))
bus->is_added = 1;
}
for (pass=0; pass < 2; pass++)
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
max = pci_scan_bridge(bus, dev, max, pass);
}
/*
* We've scanned the bus and so we know all about what's on
* the other side of any bridges that may be on this bus plus
* any devices.
*
* Return how far we've got finding sub-buses.
*/
dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max);
return max;
}
struct pci_bus * pci_create_bus(struct device *parent,
int bus, struct pci_ops *ops, void *sysdata)
{
int error;
struct pci_bus *b, *b2;
struct device *dev;
b = pci_alloc_bus();
if (!b)
return NULL;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev){
kfree(b);
return NULL;
}
b->sysdata = sysdata;
b->ops = ops;
b2 = pci_find_bus(pci_domain_nr(b), bus);
if (b2) {
/* If we already got to this bus through a different bridge, ignore it */
dev_dbg(&b2->dev, "bus already known\n");
goto err_out;
}
down_write(&pci_bus_sem);
list_add_tail(&b->node, &pci_root_buses);
up_write(&pci_bus_sem);
dev->parent = parent;
dev->release = pci_release_bus_bridge_dev;
dev_set_name(dev, "pci%04x:%02x", pci_domain_nr(b), bus);
error = device_register(dev);
if (error)
goto dev_reg_err;
b->bridge = get_device(dev);
device_enable_async_suspend(b->bridge);
if (!parent)
set_dev_node(b->bridge, pcibus_to_node(b));
b->dev.class = &pcibus_class;
b->dev.parent = b->bridge;
dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus);
error = device_register(&b->dev);
if (error)
goto class_dev_reg_err;
error = device_create_file(&b->dev, &dev_attr_cpuaffinity);
if (error)
goto dev_create_file_err;
/* Create legacy_io and legacy_mem files for this bus */
pci_create_legacy_files(b);
b->number = b->secondary = bus;
b->resource[0] = &ioport_resource;
b->resource[1] = &iomem_resource;
return b;
dev_create_file_err:
device_unregister(&b->dev);
class_dev_reg_err:
device_unregister(dev);
dev_reg_err:
down_write(&pci_bus_sem);
list_del(&b->node);
up_write(&pci_bus_sem);
err_out:
kfree(dev);
kfree(b);
return NULL;
}
struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent,
int bus, struct pci_ops *ops, void *sysdata)
{
struct pci_bus *b;
b = pci_create_bus(parent, bus, ops, sysdata);
if (b)
b->subordinate = pci_scan_child_bus(b);
return b;
}
EXPORT_SYMBOL(pci_scan_bus_parented);
#ifdef CONFIG_HOTPLUG
/**
* pci_rescan_bus - scan a PCI bus for devices.
* @bus: PCI bus to scan
*
* Scan a PCI bus and child buses for new devices, adds them,
* and enables them.
*
* Returns the max number of subordinate bus discovered.
*/
unsigned int __ref pci_rescan_bus(struct pci_bus *bus)
{
unsigned int max;
struct pci_dev *dev;
max = pci_scan_child_bus(bus);
down_read(&pci_bus_sem);
list_for_each_entry(dev, &bus->devices, bus_list)
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
if (dev->subordinate)
pci_bus_size_bridges(dev->subordinate);
up_read(&pci_bus_sem);
pci_bus_assign_resources(bus);
pci_enable_bridges(bus);
pci_bus_add_devices(bus);
return max;
}
EXPORT_SYMBOL_GPL(pci_rescan_bus);
EXPORT_SYMBOL(pci_add_new_bus);
EXPORT_SYMBOL(pci_scan_slot);
EXPORT_SYMBOL(pci_scan_bridge);
EXPORT_SYMBOL_GPL(pci_scan_child_bus);
#endif
static int __init pci_sort_bf_cmp(const struct device *d_a, const struct device *d_b)
{
const struct pci_dev *a = to_pci_dev(d_a);
const struct pci_dev *b = to_pci_dev(d_b);
if (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return 1;
if (a->bus->number < b->bus->number) return -1;
else if (a->bus->number > b->bus->number) return 1;
if (a->devfn < b->devfn) return -1;
else if (a->devfn > b->devfn) return 1;
return 0;
}
void __init pci_sort_breadthfirst(void)
{
bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp);
}