- 根目录:
- drivers
- pci
- setup-bus.c
/*
* 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>
#include <asm-generic/pci-bridge.h>
#include "pci.h"
unsigned int pci_flags;
struct pci_dev_resource {
struct list_head list;
struct resource *res;
struct pci_dev *dev;
resource_size_t start;
resource_size_t end;
resource_size_t add_size;
resource_size_t min_align;
unsigned long flags;
};
static void free_list(struct list_head *head)
{
struct pci_dev_resource *dev_res, *tmp;
list_for_each_entry_safe(dev_res, tmp, head, list) {
list_del(&dev_res->list);
kfree(dev_res);
}
}
/**
* add_to_list() - add a new resource tracker to the list
* @head: Head of the list
* @dev: device corresponding to which the resource
* belongs
* @res: The resource to be tracked
* @add_size: additional size to be optionally added
* to the resource
*/
static int add_to_list(struct list_head *head,
struct pci_dev *dev, struct resource *res,
resource_size_t add_size, resource_size_t min_align)
{
struct pci_dev_resource *tmp;
tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
if (!tmp) {
pr_warning("add_to_list: kmalloc() failed!\n");
return -ENOMEM;
}
tmp->res = res;
tmp->dev = dev;
tmp->start = res->start;
tmp->end = res->end;
tmp->flags = res->flags;
tmp->add_size = add_size;
tmp->min_align = min_align;
list_add(&tmp->list, head);
return 0;
}
static void remove_from_list(struct list_head *head,
struct resource *res)
{
struct pci_dev_resource *dev_res, *tmp;
list_for_each_entry_safe(dev_res, tmp, head, list) {
if (dev_res->res == res) {
list_del(&dev_res->list);
kfree(dev_res);
break;
}
}
}
static resource_size_t get_res_add_size(struct list_head *head,
struct resource *res)
{
struct pci_dev_resource *dev_res;
list_for_each_entry(dev_res, head, list) {
if (dev_res->res == res) {
int idx = res - &dev_res->dev->resource[0];
dev_printk(KERN_DEBUG, &dev_res->dev->dev,
"res[%d]=%pR get_res_add_size add_size %llx\n",
idx, dev_res->res,
(unsigned long long)dev_res->add_size);
return dev_res->add_size;
}
}
return 0;
}
/* Sort resources by alignment */
static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
{
int i;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *r;
struct pci_dev_resource *dev_res, *tmp;
resource_size_t r_align;
struct list_head *n;
r = &dev->resource[i];
if (r->flags & IORESOURCE_PCI_FIXED)
continue;
if (!(r->flags) || r->parent)
continue;
r_align = pci_resource_alignment(dev, r);
if (!r_align) {
dev_warn(&dev->dev, "BAR %d: %pR has bogus alignment\n",
i, r);
continue;
}
tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
if (!tmp)
panic("pdev_sort_resources(): "
"kmalloc() failed!\n");
tmp->res = r;
tmp->dev = dev;
/* fallback is smallest one or list is empty*/
n = head;
list_for_each_entry(dev_res, head, list) {
resource_size_t align;
align = pci_resource_alignment(dev_res->dev,
dev_res->res);
if (r_align > align) {
n = &dev_res->list;
break;
}
}
/* Insert it just before n*/
list_add_tail(&tmp->list, n);
}
}
static void __dev_sort_resources(struct pci_dev *dev,
struct list_head *head)
{
u16 class = dev->class >> 8;
/* Don't touch classless devices or host bridges or ioapics. */
if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
return;
/* Don't touch ioapic devices already enabled by firmware */
if (class == PCI_CLASS_SYSTEM_PIC) {
u16 command;
pci_read_config_word(dev, PCI_COMMAND, &command);
if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
return;
}
pdev_sort_resources(dev, head);
}
static inline void reset_resource(struct resource *res)
{
res->start = 0;
res->end = 0;
res->flags = 0;
}
/**
* reassign_resources_sorted() - satisfy any additional resource requests
*
* @realloc_head : head of the list tracking requests requiring additional
* resources
* @head : head of the list tracking requests with allocated
* resources
*
* Walk through each element of the realloc_head and try to procure
* additional resources for the element, provided the element
* is in the head list.
*/
static void reassign_resources_sorted(struct list_head *realloc_head,
struct list_head *head)
{
struct resource *res;
struct pci_dev_resource *add_res, *tmp;
struct pci_dev_resource *dev_res;
resource_size_t add_size;
int idx;
list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
bool found_match = false;
res = add_res->res;
/* skip resource that has been reset */
if (!res->flags)
goto out;
/* skip this resource if not found in head list */
list_for_each_entry(dev_res, head, list) {
if (dev_res->res == res) {
found_match = true;
break;
}
}
if (!found_match)/* just skip */
continue;
idx = res - &add_res->dev->resource[0];
add_size = add_res->add_size;
if (!resource_size(res)) {
res->start = add_res->start;
res->end = res->start + add_size - 1;
if (pci_assign_resource(add_res->dev, idx))
reset_resource(res);
} else {
resource_size_t align = add_res->min_align;
res->flags |= add_res->flags &
(IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
if (pci_reassign_resource(add_res->dev, idx,
add_size, align))
dev_printk(KERN_DEBUG, &add_res->dev->dev,
"failed to add %llx res[%d]=%pR\n",
(unsigned long long)add_size,
idx, res);
}
out:
list_del(&add_res->list);
kfree(add_res);
}
}
/**
* assign_requested_resources_sorted() - satisfy resource requests
*
* @head : head of the list tracking requests for resources
* @fail_head : head of the list tracking requests that could
* not be allocated
*
* Satisfy resource requests of each element in the list. Add
* requests that could not satisfied to the failed_list.
*/
static void assign_requested_resources_sorted(struct list_head *head,
struct list_head *fail_head)
{
struct resource *res;
struct pci_dev_resource *dev_res;
int idx;
list_for_each_entry(dev_res, head, list) {
res = dev_res->res;
idx = res - &dev_res->dev->resource[0];
if (resource_size(res) &&
pci_assign_resource(dev_res->dev, idx)) {
if (fail_head) {
/*
* if the failed res is for ROM BAR, and it will
* be enabled later, don't add it to the list
*/
if (!((idx == PCI_ROM_RESOURCE) &&
(!(res->flags & IORESOURCE_ROM_ENABLE))))
add_to_list(fail_head,
dev_res->dev, res,
0 /* don't care */,
0 /* don't care */);
}
reset_resource(res);
}
}
}
static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
{
struct pci_dev_resource *fail_res;
unsigned long mask = 0;
/* check failed type */
list_for_each_entry(fail_res, fail_head, list)
mask |= fail_res->flags;
/*
* one pref failed resource will set IORESOURCE_MEM,
* as we can allocate pref in non-pref range.
* Will release all assigned non-pref sibling resources
* according to that bit.
*/
return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
}
static bool pci_need_to_release(unsigned long mask, struct resource *res)
{
if (res->flags & IORESOURCE_IO)
return !!(mask & IORESOURCE_IO);
/* check pref at first */
if (res->flags & IORESOURCE_PREFETCH) {
if (mask & IORESOURCE_PREFETCH)
return true;
/* count pref if its parent is non-pref */
else if ((mask & IORESOURCE_MEM) &&
!(res->parent->flags & IORESOURCE_PREFETCH))
return true;
else
return false;
}
if (res->flags & IORESOURCE_MEM)
return !!(mask & IORESOURCE_MEM);
return false; /* should not get here */
}
static void __assign_resources_sorted(struct list_head *head,
struct list_head *realloc_head,
struct list_head *fail_head)
{
/*
* Should not assign requested resources at first.
* they could be adjacent, so later reassign can not reallocate
* them one by one in parent resource window.
* Try to assign requested + add_size at beginning
* if could do that, could get out early.
* if could not do that, we still try to assign requested at first,
* then try to reassign add_size for some resources.
*
* Separate three resource type checking if we need to release
* assigned resource after requested + add_size try.
* 1. if there is io port assign fail, will release assigned
* io port.
* 2. if there is pref mmio assign fail, release assigned
* pref mmio.
* if assigned pref mmio's parent is non-pref mmio and there
* is non-pref mmio assign fail, will release that assigned
* pref mmio.
* 3. if there is non-pref mmio assign fail or pref mmio
* assigned fail, will release assigned non-pref mmio.
*/
LIST_HEAD(save_head);
LIST_HEAD(local_fail_head);
struct pci_dev_resource *save_res;
struct pci_dev_resource *dev_res, *tmp_res;
unsigned long fail_type;
/* Check if optional add_size is there */
if (!realloc_head || list_empty(realloc_head))
goto requested_and_reassign;
/* Save original start, end, flags etc at first */
list_for_each_entry(dev_res, head, list) {
if (add_to_list(&save_head, dev_res->dev, dev_res->res, 0, 0)) {
free_list(&save_head);
goto requested_and_reassign;
}
}
/* Update res in head list with add_size in realloc_head list */
list_for_each_entry(dev_res, head, list)
dev_res->res->end += get_res_add_size(realloc_head,
dev_res->res);
/* Try updated head list with add_size added */
assign_requested_resources_sorted(head, &local_fail_head);
/* all assigned with add_size ? */
if (list_empty(&local_fail_head)) {
/* Remove head list from realloc_head list */
list_for_each_entry(dev_res, head, list)
remove_from_list(realloc_head, dev_res->res);
free_list(&save_head);
free_list(head);
return;
}
/* check failed type */
fail_type = pci_fail_res_type_mask(&local_fail_head);
/* remove not need to be released assigned res from head list etc */
list_for_each_entry_safe(dev_res, tmp_res, head, list)
if (dev_res->res->parent &&
!pci_need_to_release(fail_type, dev_res->res)) {
/* remove it from realloc_head list */
remove_from_list(realloc_head, dev_res->res);
remove_from_list(&save_head, dev_res->res);
list_del(&dev_res->list);
kfree(dev_res);
}
free_list(&local_fail_head);
/* Release assigned resource */
list_for_each_entry(dev_res, head, list)
if (dev_res->res->parent)
release_resource(dev_res->res);
/* Restore start/end/flags from saved list */
list_for_each_entry(save_res, &save_head, list) {
struct resource *res = save_res->res;
res->start = save_res->start;
res->end = save_res->end;
res->flags = save_res->flags;
}
free_list(&save_head);
requested_and_reassign:
/* Satisfy the must-have resource requests */
assign_requested_resources_sorted(head, fail_head);
/* Try to satisfy any additional optional resource
requests */
if (realloc_head)
reassign_resources_sorted(realloc_head, head);
free_list(head);
}
static void pdev_assign_resources_sorted(struct pci_dev *dev,
struct list_head *add_head,
struct list_head *fail_head)
{
LIST_HEAD(head);
__dev_sort_resources(dev, &head);
__assign_resources_sorted(&head, add_head, fail_head);
}
static void pbus_assign_resources_sorted(const struct pci_bus *bus,
struct list_head *realloc_head,
struct list_head *fail_head)
{
struct pci_dev *dev;
LIST_HEAD(head);
list_for_each_entry(dev, &bus->devices, bus_list)
__dev_sort_resources(dev, &head);
__assign_resources_sorted(&head, realloc_head, fail_head);
}
void pci_setup_cardbus(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct resource *res;
struct pci_bus_region region;
dev_info(&bridge->dev, "CardBus bridge to %pR\n",
&bus->busn_res);
res = bus->resource[0];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->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.
*/
dev_info(&bridge->dev, " bridge window %pR\n", res);
pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
region.start);
pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
region.end);
}
res = bus->resource[1];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->flags & IORESOURCE_IO) {
dev_info(&bridge->dev, " bridge window %pR\n", res);
pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
region.start);
pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
region.end);
}
res = bus->resource[2];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->flags & IORESOURCE_MEM) {
dev_info(&bridge->dev, " bridge window %pR\n", res);
pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
region.start);
pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
region.end);
}
res = bus->resource[3];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->flags & IORESOURCE_MEM) {
dev_info(&bridge->dev, " bridge window %pR\n", res);
pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
region.start);
pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
region.end);
}
}
EXPORT_SYMBOL(pci_setup_cardbus);
/* 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 pci_setup_bridge_io(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct resource *res;
struct pci_bus_region region;
unsigned long io_mask;
u8 io_base_lo, io_limit_lo;
u16 l;
u32 io_upper16;
io_mask = PCI_IO_RANGE_MASK;
if (bridge->io_window_1k)
io_mask = PCI_IO_1K_RANGE_MASK;
/* Set up the top and bottom of the PCI I/O segment for this bus. */
res = bus->resource[0];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->flags & IORESOURCE_IO) {
pci_read_config_word(bridge, PCI_IO_BASE, &l);
io_base_lo = (region.start >> 8) & io_mask;
io_limit_lo = (region.end >> 8) & io_mask;
l = ((u16) io_limit_lo << 8) | io_base_lo;
/* Set up upper 16 bits of I/O base/limit. */
io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
dev_info(&bridge->dev, " bridge window %pR\n", res);
} else {
/* Clear upper 16 bits of I/O base/limit. */
io_upper16 = 0;
l = 0x00f0;
}
/* 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_word(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);
}
static void pci_setup_bridge_mmio(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct resource *res;
struct pci_bus_region region;
u32 l;
/* Set up the top and bottom of the PCI Memory segment for this bus. */
res = bus->resource[1];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->flags & IORESOURCE_MEM) {
l = (region.start >> 16) & 0xfff0;
l |= region.end & 0xfff00000;
dev_info(&bridge->dev, " bridge window %pR\n", res);
} else {
l = 0x0000fff0;
}
pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
}
static void pci_setup_bridge_mmio_pref(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
struct resource *res;
struct pci_bus_region region;
u32 l, bu, lu;
/* 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. */
bu = lu = 0;
res = bus->resource[2];
pcibios_resource_to_bus(bridge->bus, ®ion, res);
if (res->flags & IORESOURCE_PREFETCH) {
l = (region.start >> 16) & 0xfff0;
l |= region.end & 0xfff00000;
if (res->flags & IORESOURCE_MEM_64) {
bu = upper_32_bits(region.start);
lu = upper_32_bits(region.end);
}
dev_info(&bridge->dev, " bridge window %pR\n", res);
} else {
l = 0x0000fff0;
}
pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
/* Set the upper 32 bits of PREF base & limit. */
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
}
static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
{
struct pci_dev *bridge = bus->self;
dev_info(&bridge->dev, "PCI bridge to %pR\n",
&bus->busn_res);
if (type & IORESOURCE_IO)
pci_setup_bridge_io(bus);
if (type & IORESOURCE_MEM)
pci_setup_bridge_mmio(bus);
if (type & IORESOURCE_PREFETCH)
pci_setup_bridge_mmio_pref(bus);
pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
}
void pci_setup_bridge(struct pci_bus *bus)
{
unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
IORESOURCE_PREFETCH;
__pci_setup_bridge(bus, type);
}
/* 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 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, 0xe0f0);
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,
0xffe0fff0);
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;
if ((pmem & PCI_PREF_RANGE_TYPE_MASK) ==
PCI_PREF_RANGE_TYPE_64) {
b_res[2].flags |= IORESOURCE_MEM_64;
b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
}
}
/* double check if bridge does support 64 bit pref */
if (b_res[2].flags & IORESOURCE_MEM_64) {
u32 mem_base_hi, tmp;
pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
&mem_base_hi);
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
0xffffffff);
pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
if (!tmp)
b_res[2].flags &= ~IORESOURCE_MEM_64;
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
mem_base_hi);
}
}
/* 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 *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;
pci_bus_for_each_resource(bus, r, i) {
if (r == &ioport_resource || r == &iomem_resource)
continue;
if (r && (r->flags & type_mask) == type && !r->parent)
return r;
}
return NULL;
}
static resource_size_t calculate_iosize(resource_size_t size,
resource_size_t min_size,
resource_size_t size1,
resource_size_t old_size,
resource_size_t align)
{
if (size < min_size)
size = min_size;
if (old_size == 1 )
old_size = 0;
/* 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 = ALIGN(size + size1, align);
if (size < old_size)
size = old_size;
return size;
}
static resource_size_t calculate_memsize(resource_size_t size,
resource_size_t min_size,
resource_size_t size1,
resource_size_t old_size,
resource_size_t align)
{
if (size < min_size)
size = min_size;
if (old_size == 1 )
old_size = 0;
if (size < old_size)
size = old_size;
size = ALIGN(size + size1, align);
return size;
}
resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
unsigned long type)
{
return 1;
}
#define PCI_P2P_DEFAULT_MEM_ALIGN 0x100000 /* 1MiB */
#define PCI_P2P_DEFAULT_IO_ALIGN 0x1000 /* 4KiB */
#define PCI_P2P_DEFAULT_IO_ALIGN_1K 0x400 /* 1KiB */
static resource_size_t window_alignment(struct pci_bus *bus,
unsigned long type)
{
resource_size_t align = 1, arch_align;
if (type & IORESOURCE_MEM)
align = PCI_P2P_DEFAULT_MEM_ALIGN;
else if (type & IORESOURCE_IO) {
/*
* Per spec, I/O windows are 4K-aligned, but some
* bridges have an extension to support 1K alignment.
*/
if (bus->self->io_window_1k)
align = PCI_P2P_DEFAULT_IO_ALIGN_1K;
else
align = PCI_P2P_DEFAULT_IO_ALIGN;
}
arch_align = pcibios_window_alignment(bus, type);
return max(align, arch_align);
}
/**
* pbus_size_io() - size the io window of a given bus
*
* @bus : the bus
* @min_size : the minimum io window that must to be allocated
* @add_size : additional optional io window
* @realloc_head : track the additional io window on this list
*
* Sizing the IO windows of the PCI-PCI bridge is trivial,
* since these windows have 1K or 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 pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
resource_size_t add_size, struct list_head *realloc_head)
{
struct pci_dev *dev;
struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
resource_size_t size = 0, size0 = 0, size1 = 0;
resource_size_t children_add_size = 0;
resource_size_t min_align, align;
if (!b_res)
return;
min_align = window_alignment(bus, IORESOURCE_IO);
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 = resource_size(r);
if (r_size < 0x400)
/* Might be re-aligned for ISA */
size += r_size;
else
size1 += r_size;
align = pci_resource_alignment(dev, r);
if (align > min_align)
min_align = align;
if (realloc_head)
children_add_size += get_res_add_size(realloc_head, r);
}
}
size0 = calculate_iosize(size, min_size, size1,
resource_size(b_res), min_align);
if (children_add_size > add_size)
add_size = children_add_size;
size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
calculate_iosize(size, min_size, add_size + size1,
resource_size(b_res), min_align);
if (!size0 && !size1) {
if (b_res->start || b_res->end)
dev_info(&bus->self->dev, "disabling bridge window "
"%pR to %pR (unused)\n", b_res,
&bus->busn_res);
b_res->flags = 0;
return;
}
b_res->start = min_align;
b_res->end = b_res->start + size0 - 1;
b_res->flags |= IORESOURCE_STARTALIGN;
if (size1 > size0 && realloc_head) {
add_to_list(realloc_head, bus->self, b_res, size1-size0,
min_align);
dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window "
"%pR to %pR add_size %llx\n", b_res,
&bus->busn_res,
(unsigned long long)size1-size0);
}
}
static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
int max_order)
{
resource_size_t align = 0;
resource_size_t min_align = 0;
int order;
for (order = 0; order <= max_order; order++) {
resource_size_t align1 = 1;
align1 <<= (order + 20);
if (!align)
min_align = align1;
else if (ALIGN(align + min_align, min_align) < align1)
min_align = align1 >> 1;
align += aligns[order];
}
return min_align;
}
/**
* pbus_size_mem() - size the memory window of a given bus
*
* @bus : the bus
* @mask: mask the resource flag, then compare it with type
* @type: the type of free resource from bridge
* @min_size : the minimum memory window that must to be allocated
* @add_size : additional optional memory window
* @realloc_head : track the additional memory window on this list
*
* Calculate the size of the bus and minimal alignment which
* guarantees that all child resources fit in this size.
*/
static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
unsigned long type, resource_size_t min_size,
resource_size_t add_size,
struct list_head *realloc_head)
{
struct pci_dev *dev;
resource_size_t min_align, align, size, size0, size1;
resource_size_t aligns[12]; /* Alignments from 1Mb to 2Gb */
int order, max_order;
struct resource *b_res = find_free_bus_resource(bus, type);
unsigned int mem64_mask = 0;
resource_size_t children_add_size = 0;
if (!b_res)
return 0;
memset(aligns, 0, sizeof(aligns));
max_order = 0;
size = 0;
mem64_mask = b_res->flags & IORESOURCE_MEM_64;
b_res->flags &= ~IORESOURCE_MEM_64;
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];
resource_size_t r_size;
if (r->parent || (r->flags & mask) != type)
continue;
r_size = resource_size(r);
#ifdef CONFIG_PCI_IOV
/* put SRIOV requested res to the optional list */
if (realloc_head && i >= PCI_IOV_RESOURCES &&
i <= PCI_IOV_RESOURCE_END) {
r->end = r->start - 1;
add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
children_add_size += r_size;
continue;
}
#endif
/* For bridges size != alignment */
align = pci_resource_alignment(dev, r);
order = __ffs(align) - 20;
if (order > 11) {
dev_warn(&dev->dev, "disabling BAR %d: %pR "
"(bad alignment %#llx)\n", i, r,
(unsigned long long) align);
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;
mem64_mask &= r->flags & IORESOURCE_MEM_64;
if (realloc_head)
children_add_size += get_res_add_size(realloc_head, r);
}
}
min_align = calculate_mem_align(aligns, max_order);
min_align = max(min_align, window_alignment(bus, b_res->flags));
size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
if (children_add_size > add_size)
add_size = children_add_size;
size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
calculate_memsize(size, min_size, add_size,
resource_size(b_res), min_align);
if (!size0 && !size1) {
if (b_res->start || b_res->end)
dev_info(&bus->self->dev, "disabling bridge window "
"%pR to %pR (unused)\n", b_res,
&bus->busn_res);
b_res->flags = 0;
return 1;
}
b_res->start = min_align;
b_res->end = size0 + min_align - 1;
b_res->flags |= IORESOURCE_STARTALIGN | mem64_mask;
if (size1 > size0 && realloc_head) {
add_to_list(realloc_head, bus->self, b_res, size1-size0, min_align);
dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window "
"%pR to %pR add_size %llx\n", b_res,
&bus->busn_res, (unsigned long long)size1-size0);
}
return 1;
}
unsigned long pci_cardbus_resource_alignment(struct resource *res)
{
if (res->flags & IORESOURCE_IO)
return pci_cardbus_io_size;
if (res->flags & IORESOURCE_MEM)
return pci_cardbus_mem_size;
return 0;
}
static void pci_bus_size_cardbus(struct pci_bus *bus,
struct list_head *realloc_head)
{
struct pci_dev *bridge = bus->self;
struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
u16 ctrl;
if (b_res[0].parent)
goto handle_b_res_1;
/*
* Reserve some resources for CardBus. We reserve
* a fixed amount of bus space for CardBus bridges.
*/
b_res[0].start = pci_cardbus_io_size;
b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
b_res[0].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
if (realloc_head) {
b_res[0].end -= pci_cardbus_io_size;
add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
pci_cardbus_io_size);
}
handle_b_res_1:
if (b_res[1].parent)
goto handle_b_res_2;
b_res[1].start = pci_cardbus_io_size;
b_res[1].end = b_res[1].start + pci_cardbus_io_size - 1;
b_res[1].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
if (realloc_head) {
b_res[1].end -= pci_cardbus_io_size;
add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size,
pci_cardbus_io_size);
}
handle_b_res_2:
/* MEM1 must not be pref mmio */
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
}
/*
* 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 (b_res[2].parent)
goto handle_b_res_3;
/*
* 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 = pci_cardbus_mem_size;
b_res[2].end = b_res[2].start + pci_cardbus_mem_size - 1;
b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
IORESOURCE_STARTALIGN;
if (realloc_head) {
b_res[2].end -= pci_cardbus_mem_size;
add_to_list(realloc_head, bridge, b_res+2,
pci_cardbus_mem_size, pci_cardbus_mem_size);
}
/* reduce that to half */
b_res_3_size = pci_cardbus_mem_size;
}
handle_b_res_3:
if (b_res[3].parent)
goto handle_done;
b_res[3].start = pci_cardbus_mem_size;
b_res[3].end = b_res[3].start + b_res_3_size - 1;
b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
if (realloc_head) {
b_res[3].end -= b_res_3_size;
add_to_list(realloc_head, bridge, b_res+3, b_res_3_size,
pci_cardbus_mem_size);
}
handle_done:
;
}
void __ref __pci_bus_size_bridges(struct pci_bus *bus,
struct list_head *realloc_head)
{
struct pci_dev *dev;
unsigned long mask, prefmask;
resource_size_t additional_mem_size = 0, additional_io_size = 0;
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, realloc_head);
break;
case PCI_CLASS_BRIDGE_PCI:
default:
__pci_bus_size_bridges(b, realloc_head);
break;
}
}
/* The root bus? */
if (pci_is_root_bus(bus))
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);
if (bus->self->is_hotplug_bridge) {
additional_io_size = pci_hotplug_io_size;
additional_mem_size = pci_hotplug_mem_size;
}
/*
* Follow thru
*/
default:
pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
additional_io_size, realloc_head);
/* 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,
realloc_head ? 0 : additional_mem_size,
additional_mem_size, realloc_head))
mask = prefmask; /* Success, size non-prefetch only. */
else
additional_mem_size += additional_mem_size;
pbus_size_mem(bus, mask, IORESOURCE_MEM,
realloc_head ? 0 : additional_mem_size,
additional_mem_size, realloc_head);
break;
}
}
void __ref pci_bus_size_bridges(struct pci_bus *bus)
{
__pci_bus_size_bridges(bus, NULL);
}
EXPORT_SYMBOL(pci_bus_size_bridges);
void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
struct list_head *realloc_head,
struct list_head *fail_head)
{
struct pci_bus *b;
struct pci_dev *dev;
pbus_assign_resources_sorted(bus, realloc_head, fail_head);
list_for_each_entry(dev, &bus->devices, bus_list) {
b = dev->subordinate;
if (!b)
continue;
__pci_bus_assign_resources(b, realloc_head, fail_head);
switch (dev->class >> 8) {
case PCI_CLASS_BRIDGE_PCI:
if (!pci_is_enabled(dev))
pci_setup_bridge(b);
break;
case PCI_CLASS_BRIDGE_CARDBUS:
pci_setup_cardbus(b);
break;
default:
dev_info(&dev->dev, "not setting up bridge for bus "
"%04x:%02x\n", pci_domain_nr(b), b->number);
break;
}
}
}
void __ref pci_bus_assign_resources(const struct pci_bus *bus)
{
__pci_bus_assign_resources(bus, NULL, NULL);
}
EXPORT_SYMBOL(pci_bus_assign_resources);
static void __ref __pci_bridge_assign_resources(const struct pci_dev *bridge,
struct list_head *add_head,
struct list_head *fail_head)
{
struct pci_bus *b;
pdev_assign_resources_sorted((struct pci_dev *)bridge,
add_head, fail_head);
b = bridge->subordinate;
if (!b)
return;
__pci_bus_assign_resources(b, add_head, fail_head);
switch (bridge->class >> 8) {
case PCI_CLASS_BRIDGE_PCI:
pci_setup_bridge(b);
break;
case PCI_CLASS_BRIDGE_CARDBUS:
pci_setup_cardbus(b);
break;
default:
dev_info(&bridge->dev, "not setting up bridge for bus "
"%04x:%02x\n", pci_domain_nr(b), b->number);
break;
}
}
static void pci_bridge_release_resources(struct pci_bus *bus,
unsigned long type)
{
int idx;
bool changed = false;
struct pci_dev *dev;
struct resource *r;
unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
IORESOURCE_PREFETCH;
dev = bus->self;
for (idx = PCI_BRIDGE_RESOURCES; idx <= PCI_BRIDGE_RESOURCE_END;
idx++) {
r = &dev->resource[idx];
if ((r->flags & type_mask) != type)
continue;
if (!r->parent)
continue;
/*
* if there are children under that, we should release them
* all
*/
release_child_resources(r);
if (!release_resource(r)) {
dev_printk(KERN_DEBUG, &dev->dev,
"resource %d %pR released\n", idx, r);
/* keep the old size */
r->end = resource_size(r) - 1;
r->start = 0;
r->flags = 0;
changed = true;
}
}
if (changed) {
/* avoiding touch the one without PREF */
if (type & IORESOURCE_PREFETCH)
type = IORESOURCE_PREFETCH;
__pci_setup_bridge(bus, type);
}
}
enum release_type {
leaf_only,
whole_subtree,
};
/*
* try to release pci bridge resources that is from leaf bridge,
* so we can allocate big new one later
*/
static void __ref pci_bus_release_bridge_resources(struct pci_bus *bus,
unsigned long type,
enum release_type rel_type)
{
struct pci_dev *dev;
bool is_leaf_bridge = true;
list_for_each_entry(dev, &bus->devices, bus_list) {
struct pci_bus *b = dev->subordinate;
if (!b)
continue;
is_leaf_bridge = false;
if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
continue;
if (rel_type == whole_subtree)
pci_bus_release_bridge_resources(b, type,
whole_subtree);
}
if (pci_is_root_bus(bus))
return;
if ((bus->self->class >> 8) != PCI_CLASS_BRIDGE_PCI)
return;
if ((rel_type == whole_subtree) || is_leaf_bridge)
pci_bridge_release_resources(bus, type);
}
static void pci_bus_dump_res(struct pci_bus *bus)
{
struct resource *res;
int i;
pci_bus_for_each_resource(bus, res, i) {
if (!res || !res->end || !res->flags)
continue;
dev_printk(KERN_DEBUG, &bus->dev, "resource %d %pR\n", i, res);
}
}
static void pci_bus_dump_resources(struct pci_bus *bus)
{
struct pci_bus *b;
struct pci_dev *dev;
pci_bus_dump_res(bus);
list_for_each_entry(dev, &bus->devices, bus_list) {
b = dev->subordinate;
if (!b)
continue;
pci_bus_dump_resources(b);
}
}
static int pci_bus_get_depth(struct pci_bus *bus)
{
int depth = 0;
struct pci_bus *child_bus;
list_for_each_entry(child_bus, &bus->children, node){
int ret;
ret = pci_bus_get_depth(child_bus);
if (ret + 1 > depth)
depth = ret + 1;
}
return depth;
}
/*
* -1: undefined, will auto detect later
* 0: disabled by user
* 1: disabled by auto detect
* 2: enabled by user
* 3: enabled by auto detect
*/
enum enable_type {
undefined = -1,
user_disabled,
auto_disabled,
user_enabled,
auto_enabled,
};
static enum enable_type pci_realloc_enable = undefined;
void __init pci_realloc_get_opt(char *str)
{
if (!strncmp(str, "off", 3))
pci_realloc_enable = user_disabled;
else if (!strncmp(str, "on", 2))
pci_realloc_enable = user_enabled;
}
static bool pci_realloc_enabled(enum enable_type enable)
{
return enable >= user_enabled;
}
#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)
static int iov_resources_unassigned(struct pci_dev *dev, void *data)
{
int i;
bool *unassigned = data;
for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) {
struct resource *r = &dev->resource[i];
struct pci_bus_region region;
/* Not assigned or rejected by kernel? */
if (!r->flags)
continue;
pcibios_resource_to_bus(dev->bus, ®ion, r);
if (!region.start) {
*unassigned = true;
return 1; /* return early from pci_walk_bus() */
}
}
return 0;
}
static enum enable_type pci_realloc_detect(struct pci_bus *bus,
enum enable_type enable_local)
{
bool unassigned = false;
if (enable_local != undefined)
return enable_local;
pci_walk_bus(bus, iov_resources_unassigned, &unassigned);
if (unassigned)
return auto_enabled;
return enable_local;
}
#else
static enum enable_type pci_realloc_detect(struct pci_bus *bus,
enum enable_type enable_local)
{
return enable_local;
}
#endif
/*
* first try will not touch pci bridge res
* second and later try will clear small leaf bridge res
* will stop till to the max depth if can not find good one
*/
void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
{
LIST_HEAD(realloc_head); /* list of resources that
want additional resources */
struct list_head *add_list = NULL;
int tried_times = 0;
enum release_type rel_type = leaf_only;
LIST_HEAD(fail_head);
struct pci_dev_resource *fail_res;
unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
IORESOURCE_PREFETCH;
int pci_try_num = 1;
enum enable_type enable_local;
/* don't realloc if asked to do so */
enable_local = pci_realloc_detect(bus, pci_realloc_enable);
if (pci_realloc_enabled(enable_local)) {
int max_depth = pci_bus_get_depth(bus);
pci_try_num = max_depth + 1;
dev_printk(KERN_DEBUG, &bus->dev,
"max bus depth: %d pci_try_num: %d\n",
max_depth, pci_try_num);
}
again:
/*
* last try will use add_list, otherwise will try good to have as
* must have, so can realloc parent bridge resource
*/
if (tried_times + 1 == pci_try_num)
add_list = &realloc_head;
/* Depth first, calculate sizes and alignments of all
subordinate buses. */
__pci_bus_size_bridges(bus, add_list);
/* Depth last, allocate resources and update the hardware. */
__pci_bus_assign_resources(bus, add_list, &fail_head);
if (add_list)
BUG_ON(!list_empty(add_list));
tried_times++;
/* any device complain? */
if (list_empty(&fail_head))
goto dump;
if (tried_times >= pci_try_num) {
if (enable_local == undefined)
dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
else if (enable_local == auto_enabled)
dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
free_list(&fail_head);
goto dump;
}
dev_printk(KERN_DEBUG, &bus->dev,
"No. %d try to assign unassigned res\n", tried_times + 1);
/* third times and later will not check if it is leaf */
if ((tried_times + 1) > 2)
rel_type = whole_subtree;
/*
* Try to release leaf bridge's resources that doesn't fit resource of
* child device under that bridge
*/
list_for_each_entry(fail_res, &fail_head, list)
pci_bus_release_bridge_resources(fail_res->dev->bus,
fail_res->flags & type_mask,
rel_type);
/* restore size and flags */
list_for_each_entry(fail_res, &fail_head, list) {
struct resource *res = fail_res->res;
res->start = fail_res->start;
res->end = fail_res->end;
res->flags = fail_res->flags;
if (fail_res->dev->subordinate)
res->flags = 0;
}
free_list(&fail_head);
goto again;
dump:
/* dump the resource on buses */
pci_bus_dump_resources(bus);
}
void __init pci_assign_unassigned_resources(void)
{
struct pci_bus *root_bus;
list_for_each_entry(root_bus, &pci_root_buses, node)
pci_assign_unassigned_root_bus_resources(root_bus);
}
void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
{
struct pci_bus *parent = bridge->subordinate;
LIST_HEAD(add_list); /* list of resources that
want additional resources */
int tried_times = 0;
LIST_HEAD(fail_head);
struct pci_dev_resource *fail_res;
int retval;
unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
IORESOURCE_PREFETCH;
again:
__pci_bus_size_bridges(parent, &add_list);
__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
BUG_ON(!list_empty(&add_list));
tried_times++;
if (list_empty(&fail_head))
goto enable_all;
if (tried_times >= 2) {
/* still fail, don't need to try more */
free_list(&fail_head);
goto enable_all;
}
printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
tried_times + 1);
/*
* Try to release leaf bridge's resources that doesn't fit resource of
* child device under that bridge
*/
list_for_each_entry(fail_res, &fail_head, list)
pci_bus_release_bridge_resources(fail_res->dev->bus,
fail_res->flags & type_mask,
whole_subtree);
/* restore size and flags */
list_for_each_entry(fail_res, &fail_head, list) {
struct resource *res = fail_res->res;
res->start = fail_res->start;
res->end = fail_res->end;
res->flags = fail_res->flags;
if (fail_res->dev->subordinate)
res->flags = 0;
}
free_list(&fail_head);
goto again;
enable_all:
retval = pci_reenable_device(bridge);
if (retval)
dev_err(&bridge->dev, "Error reenabling bridge (%d)\n", retval);
pci_set_master(bridge);
}
EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
{
struct pci_dev *dev;
LIST_HEAD(add_list); /* list of resources that
want additional resources */
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,
&add_list);
up_read(&pci_bus_sem);
__pci_bus_assign_resources(bus, &add_list, NULL);
BUG_ON(!list_empty(&add_list));
}