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linux/drivers/pci/probe.c
Bjorn Helgaas 7e124c4051 Merge branch 'pci/trivial' 
- Fix typos and comments (Bjorn Helgaas)

  - Fix Kconfig whitespace errors (Krzysztof Kozlowski)

* pci/trivial:
  PCI: Fix indentation
  PCI: Fix typos
  PCI: Remove useless comments and tidy others
  PCI: Remove unnecessary includes

# Conflicts:
#	drivers/pci/probe.c
2019-11-28 08:54:55 -06:00

3225 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* PCI detection and setup code
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/of_device.h>
#include <linux/of_pci.h>
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/cpumask.h>
#include <linux/aer.h>
#include <linux/acpi.h>
#include <linux/hypervisor.h>
#include <linux/irqdomain.h>
#include <linux/pm_runtime.h>
#include "pci.h"
#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
#define CARDBUS_RESERVE_BUSNR 3
static struct resource busn_resource = {
.name = "PCI busn",
.start = 0,
.end = 255,
.flags = IORESOURCE_BUS,
};
/* Ugh. Need to stop exporting this to modules. */
LIST_HEAD(pci_root_buses);
EXPORT_SYMBOL(pci_root_buses);
static LIST_HEAD(pci_domain_busn_res_list);
struct pci_domain_busn_res {
struct list_head list;
struct resource res;
int domain_nr;
};
static struct resource *get_pci_domain_busn_res(int domain_nr)
{
struct pci_domain_busn_res *r;
list_for_each_entry(r, &pci_domain_busn_res_list, list)
if (r->domain_nr == domain_nr)
return &r->res;
r = kzalloc(sizeof(*r), GFP_KERNEL);
if (!r)
return NULL;
r->domain_nr = domain_nr;
r->res.start = 0;
r->res.end = 0xff;
r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED;
list_add_tail(&r->list, &pci_domain_busn_res_list);
return &r->res;
}
/*
* 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_next_device(&pci_bus_type, NULL);
no_devices = (dev == NULL);
put_device(dev);
return no_devices;
}
EXPORT_SYMBOL(no_pci_devices);
/*
* PCI Bus Class
*/
static void release_pcibus_dev(struct device *dev)
{
struct pci_bus *pci_bus = to_pci_bus(dev);
put_device(pci_bus->bridge);
pci_bus_remove_resources(pci_bus);
pci_release_bus_of_node(pci_bus);
kfree(pci_bus);
}
static struct class pcibus_class = {
.name = "pci_bus",
.dev_release = &release_pcibus_dev,
.dev_groups = pcibus_groups,
};
static int __init pcibus_class_init(void)
{
return class_register(&pcibus_class);
}
postcore_initcall(pcibus_class_init);
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);
/*
* base == maxbase can be valid only if the BAR has already been
* programmed with all 1s.
*/
if (base == maxbase && ((base | (size - 1)) & mask) != mask)
return 0;
return size;
}
static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar)
{
u32 mem_type;
unsigned long flags;
if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
flags = bar & ~PCI_BASE_ADDRESS_IO_MASK;
flags |= IORESOURCE_IO;
return flags;
}
flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK;
flags |= IORESOURCE_MEM;
if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
flags |= IORESOURCE_PREFETCH;
mem_type = bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK;
switch (mem_type) {
case PCI_BASE_ADDRESS_MEM_TYPE_32:
break;
case PCI_BASE_ADDRESS_MEM_TYPE_1M:
/* 1M mem BAR treated as 32-bit BAR */
break;
case PCI_BASE_ADDRESS_MEM_TYPE_64:
flags |= IORESOURCE_MEM_64;
break;
default:
/* mem unknown type treated as 32-bit BAR */
break;
}
return flags;
}
#define PCI_COMMAND_DECODE_ENABLE (PCI_COMMAND_MEMORY | PCI_COMMAND_IO)
/**
* 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 = 0, sz = 0, mask;
u64 l64, sz64, mask64;
u16 orig_cmd;
struct pci_bus_region region, inverted_region;
mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
/* No printks while decoding is disabled! */
if (!dev->mmio_always_on) {
pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) {
pci_write_config_word(dev, PCI_COMMAND,
orig_cmd & ~PCI_COMMAND_DECODE_ENABLE);
}
}
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);
/*
* 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 == 0xffffffff)
sz = 0;
/*
* 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) {
res->flags = decode_bar(dev, l);
res->flags |= IORESOURCE_SIZEALIGN;
if (res->flags & IORESOURCE_IO) {
l64 = l & PCI_BASE_ADDRESS_IO_MASK;
sz64 = sz & PCI_BASE_ADDRESS_IO_MASK;
mask64 = PCI_BASE_ADDRESS_IO_MASK & (u32)IO_SPACE_LIMIT;
} else {
l64 = l & PCI_BASE_ADDRESS_MEM_MASK;
sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
mask64 = (u32)PCI_BASE_ADDRESS_MEM_MASK;
}
} else {
if (l & PCI_ROM_ADDRESS_ENABLE)
res->flags |= IORESOURCE_ROM_ENABLE;
l64 = l & PCI_ROM_ADDRESS_MASK;
sz64 = sz & PCI_ROM_ADDRESS_MASK;
mask64 = PCI_ROM_ADDRESS_MASK;
}
if (res->flags & IORESOURCE_MEM_64) {
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);
mask64 |= ((u64)~0 << 32);
}
if (!dev->mmio_always_on && (orig_cmd & PCI_COMMAND_DECODE_ENABLE))
pci_write_config_word(dev, PCI_COMMAND, orig_cmd);
if (!sz64)
goto fail;
sz64 = pci_size(l64, sz64, mask64);
if (!sz64) {
pci_info(dev, FW_BUG "reg 0x%x: invalid BAR (can't size)\n",
pos);
goto fail;
}
if (res->flags & IORESOURCE_MEM_64) {
if ((sizeof(pci_bus_addr_t) < 8 || sizeof(resource_size_t) < 8)
&& sz64 > 0x100000000ULL) {
res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED;
res->start = 0;
res->end = 0;
pci_err(dev, "reg 0x%x: can't handle BAR larger than 4GB (size %#010llx)\n",
pos, (unsigned long long)sz64);
goto out;
}
if ((sizeof(pci_bus_addr_t) < 8) && l) {
/* Above 32-bit boundary; try to reallocate */
res->flags |= IORESOURCE_UNSET;
res->start = 0;
res->end = sz64 - 1;
pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n",
pos, (unsigned long long)l64);
goto out;
}
}
region.start = l64;
region.end = l64 + sz64 - 1;
pcibios_bus_to_resource(dev->bus, res, &region);
pcibios_resource_to_bus(dev->bus, &inverted_region, res);
/*
* If "A" is a BAR value (a bus address), "bus_to_resource(A)" is
* the corresponding resource address (the physical address used by
* the CPU. Converting that resource address back to a bus address
* should yield the original BAR value:
*
* resource_to_bus(bus_to_resource(A)) == A
*
* If it doesn't, CPU accesses to "bus_to_resource(A)" will not
* be claimed by the device.
*/
if (inverted_region.start != region.start) {
res->flags |= IORESOURCE_UNSET;
res->start = 0;
res->end = region.end - region.start;
pci_info(dev, "reg 0x%x: initial BAR value %#010llx invalid\n",
pos, (unsigned long long)region.start);
}
goto out;
fail:
res->flags = 0;
out:
if (res->flags)
pci_info(dev, "reg 0x%x: %pR\n", pos, res);
return (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
}
static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
{
unsigned int pos, reg;
if (dev->non_compliant_bars)
return;
/* Per PCIe r4.0, sec 9.3.4.1.11, the VF BARs are all RO Zero */
if (dev->is_virtfn)
return;
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_SIZEALIGN;
__pci_read_base(dev, pci_bar_mem32, res, rom);
}
}
static void pci_read_bridge_windows(struct pci_dev *bridge)
{
u16 io;
u32 pmem, tmp;
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)
bridge->io_window = 1;
/*
* 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)
return;
bridge->pref_window = 1;
if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
/*
* Bridge claims to have a 64-bit prefetchable memory
* window; verify that the upper bits are actually
* writable.
*/
pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem);
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
0xffffffff);
pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem);
if (tmp)
bridge->pref_64_window = 1;
}
}
static void pci_read_bridge_io(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
u8 io_base_lo, io_limit_lo;
unsigned long io_mask, io_granularity, base, limit;
struct pci_bus_region region;
struct resource *res;
io_mask = PCI_IO_RANGE_MASK;
io_granularity = 0x1000;
if (dev->io_window_1k) {
/* Support 1K I/O space granularity */
io_mask = PCI_IO_1K_RANGE_MASK;
io_granularity = 0x400;
}
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 & io_mask) << 8;
limit = (io_limit_lo & io_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 |= ((unsigned long) io_base_hi << 16);
limit |= ((unsigned long) io_limit_hi << 16);
}
if (base <= limit) {
res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
region.start = base;
region.end = limit + io_granularity - 1;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, " bridge window %pR\n", res);
}
}
static void 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 pci_bus_region region;
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 = ((unsigned long) mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
limit = ((unsigned long) mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
if (base <= limit) {
res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
region.start = base;
region.end = limit + 0xfffff;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, " bridge window %pR\n", res);
}
}
static void pci_read_bridge_mmio_pref(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
u16 mem_base_lo, mem_limit_lo;
u64 base64, limit64;
pci_bus_addr_t base, limit;
struct pci_bus_region region;
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);
base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
limit64 = (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) {
base64 |= (u64) mem_base_hi << 32;
limit64 |= (u64) mem_limit_hi << 32;
}
}
base = (pci_bus_addr_t) base64;
limit = (pci_bus_addr_t) limit64;
if (base != base64) {
pci_err(dev, "can't handle bridge window above 4GB (bus address %#010llx)\n",
(unsigned long long) base64);
return;
}
if (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;
region.start = base;
region.end = limit + 0xfffff;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, " bridge window %pR\n", res);
}
}
void 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;
pci_info(dev, "PCI bridge to %pR%s\n",
&child->busn_res,
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 && res->flags) {
pci_bus_add_resource(child, res,
PCI_SUBTRACTIVE_DECODE);
pci_info(dev, " bridge window %pR (subtractive decode)\n",
res);
}
}
}
}
static struct pci_bus *pci_alloc_bus(struct pci_bus *parent)
{
struct pci_bus *b;
b = kzalloc(sizeof(*b), GFP_KERNEL);
if (!b)
return NULL;
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;
#ifdef CONFIG_PCI_DOMAINS_GENERIC
if (parent)
b->domain_nr = parent->domain_nr;
#endif
return b;
}
static void devm_pci_release_host_bridge_dev(struct device *dev)
{
struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
if (bridge->release_fn)
bridge->release_fn(bridge);
pci_free_resource_list(&bridge->windows);
pci_free_resource_list(&bridge->dma_ranges);
}
static void pci_release_host_bridge_dev(struct device *dev)
{
devm_pci_release_host_bridge_dev(dev);
kfree(to_pci_host_bridge(dev));
}
static void pci_init_host_bridge(struct pci_host_bridge *bridge)
{
INIT_LIST_HEAD(&bridge->windows);
INIT_LIST_HEAD(&bridge->dma_ranges);
/*
* We assume we can manage these PCIe features. Some systems may
* reserve these for use by the platform itself, e.g., an ACPI BIOS
* may implement its own AER handling and use _OSC to prevent the
* OS from interfering.
*/
bridge->native_aer = 1;
bridge->native_pcie_hotplug = 1;
bridge->native_shpc_hotplug = 1;
bridge->native_pme = 1;
bridge->native_ltr = 1;
}
struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
{
struct pci_host_bridge *bridge;
bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL);
if (!bridge)
return NULL;
pci_init_host_bridge(bridge);
bridge->dev.release = pci_release_host_bridge_dev;
return bridge;
}
EXPORT_SYMBOL(pci_alloc_host_bridge);
struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,
size_t priv)
{
struct pci_host_bridge *bridge;
bridge = devm_kzalloc(dev, sizeof(*bridge) + priv, GFP_KERNEL);
if (!bridge)
return NULL;
pci_init_host_bridge(bridge);
bridge->dev.release = devm_pci_release_host_bridge_dev;
return bridge;
}
EXPORT_SYMBOL(devm_pci_alloc_host_bridge);
void pci_free_host_bridge(struct pci_host_bridge *bridge)
{
pci_free_resource_list(&bridge->windows);
pci_free_resource_list(&bridge->dma_ranges);
kfree(bridge);
}
EXPORT_SYMBOL(pci_free_host_bridge);
static const 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 */
};
const unsigned char pcie_link_speed[] = {
PCI_SPEED_UNKNOWN, /* 0 */
PCIE_SPEED_2_5GT, /* 1 */
PCIE_SPEED_5_0GT, /* 2 */
PCIE_SPEED_8_0GT, /* 3 */
PCIE_SPEED_16_0GT, /* 4 */
PCIE_SPEED_32_0GT, /* 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 & PCI_EXP_LNKSTA_CLS];
}
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 + PCI_X_BRIDGE_SSTATUS,
&status);
if (status & PCI_X_SSTATUS_533MHZ) {
max = PCI_SPEED_133MHz_PCIX_533;
} else if (status & PCI_X_SSTATUS_266MHZ) {
max = PCI_SPEED_133MHz_PCIX_266;
} else if (status & PCI_X_SSTATUS_133MHZ) {
if ((status & PCI_X_SSTATUS_VERS) == PCI_X_SSTATUS_V2)
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 & PCI_X_SSTATUS_FREQ) >> 6];
return;
}
if (pci_is_pcie(bridge)) {
u32 linkcap;
u16 linksta;
pcie_capability_read_dword(bridge, PCI_EXP_LNKCAP, &linkcap);
bus->max_bus_speed = pcie_link_speed[linkcap & PCI_EXP_LNKCAP_SLS];
bridge->link_active_reporting = !!(linkcap & PCI_EXP_LNKCAP_DLLLARC);
pcie_capability_read_word(bridge, PCI_EXP_LNKSTA, &linksta);
pcie_update_link_speed(bus, linksta);
}
}
static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
{
struct irq_domain *d;
/*
* Any firmware interface that can resolve the msi_domain
* should be called from here.
*/
d = pci_host_bridge_of_msi_domain(bus);
if (!d)
d = pci_host_bridge_acpi_msi_domain(bus);
#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
/*
* If no IRQ domain was found via the OF tree, try looking it up
* directly through the fwnode_handle.
*/
if (!d) {
struct fwnode_handle *fwnode = pci_root_bus_fwnode(bus);
if (fwnode)
d = irq_find_matching_fwnode(fwnode,
DOMAIN_BUS_PCI_MSI);
}
#endif
return d;
}
static void pci_set_bus_msi_domain(struct pci_bus *bus)
{
struct irq_domain *d;
struct pci_bus *b;
/*
* The bus can be a root bus, a subordinate bus, or a virtual bus
* created by an SR-IOV device. Walk up to the first bridge device
* found or derive the domain from the host bridge.
*/
for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) {
if (b->self)
d = dev_get_msi_domain(&b->self->dev);
}
if (!d)
d = pci_host_bridge_msi_domain(b);
dev_set_msi_domain(&bus->dev, d);
}
static int pci_register_host_bridge(struct pci_host_bridge *bridge)
{
struct device *parent = bridge->dev.parent;
struct resource_entry *window, *n;
struct pci_bus *bus, *b;
resource_size_t offset;
LIST_HEAD(resources);
struct resource *res;
char addr[64], *fmt;
const char *name;
int err;
bus = pci_alloc_bus(NULL);
if (!bus)
return -ENOMEM;
bridge->bus = bus;
/* Temporarily move resources off the list */
list_splice_init(&bridge->windows, &resources);
bus->sysdata = bridge->sysdata;
bus->msi = bridge->msi;
bus->ops = bridge->ops;
bus->number = bus->busn_res.start = bridge->busnr;
#ifdef CONFIG_PCI_DOMAINS_GENERIC
bus->domain_nr = pci_bus_find_domain_nr(bus, parent);
#endif
b = pci_find_bus(pci_domain_nr(bus), bridge->busnr);
if (b) {
/* Ignore it if we already got here via a different bridge */
dev_dbg(&b->dev, "bus already known\n");
err = -EEXIST;
goto free;
}
dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(bus),
bridge->busnr);
err = pcibios_root_bridge_prepare(bridge);
if (err)
goto free;
err = device_register(&bridge->dev);
if (err)
put_device(&bridge->dev);
bus->bridge = get_device(&bridge->dev);
device_enable_async_suspend(bus->bridge);
pci_set_bus_of_node(bus);
pci_set_bus_msi_domain(bus);
if (!parent)
set_dev_node(bus->bridge, pcibus_to_node(bus));
bus->dev.class = &pcibus_class;
bus->dev.parent = bus->bridge;
dev_set_name(&bus->dev, "%04x:%02x", pci_domain_nr(bus), bus->number);
name = dev_name(&bus->dev);
err = device_register(&bus->dev);
if (err)
goto unregister;
pcibios_add_bus(bus);
/* Create legacy_io and legacy_mem files for this bus */
pci_create_legacy_files(bus);
if (parent)
dev_info(parent, "PCI host bridge to bus %s\n", name);
else
pr_info("PCI host bridge to bus %s\n", name);
if (nr_node_ids > 1 && pcibus_to_node(bus) == NUMA_NO_NODE)
dev_warn(&bus->dev, "Unknown NUMA node; performance will be reduced\n");
/* Add initial resources to the bus */
resource_list_for_each_entry_safe(window, n, &resources) {
list_move_tail(&window->node, &bridge->windows);
offset = window->offset;
res = window->res;
if (res->flags & IORESOURCE_BUS)
pci_bus_insert_busn_res(bus, bus->number, res->end);
else
pci_bus_add_resource(bus, res, 0);
if (offset) {
if (resource_type(res) == IORESOURCE_IO)
fmt = " (bus address [%#06llx-%#06llx])";
else
fmt = " (bus address [%#010llx-%#010llx])";
snprintf(addr, sizeof(addr), fmt,
(unsigned long long)(res->start - offset),
(unsigned long long)(res->end - offset));
} else
addr[0] = '\0';
dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr);
}
down_write(&pci_bus_sem);
list_add_tail(&bus->node, &pci_root_buses);
up_write(&pci_bus_sem);
return 0;
unregister:
put_device(&bridge->dev);
device_unregister(&bridge->dev);
free:
kfree(bus);
return err;
}
static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev *bridge)
{
int pos;
u32 status;
/*
* If extended config space isn't accessible on a bridge's primary
* bus, we certainly can't access it on the secondary bus.
*/
if (bridge->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG)
return false;
/*
* PCIe Root Ports and switch ports are PCIe on both sides, so if
* extended config space is accessible on the primary, it's also
* accessible on the secondary.
*/
if (pci_is_pcie(bridge) &&
(pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT ||
pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM ||
pci_pcie_type(bridge) == PCI_EXP_TYPE_DOWNSTREAM))
return true;
/*
* For the other bridge types:
* - PCI-to-PCI bridges
* - PCIe-to-PCI/PCI-X forward bridges
* - PCI/PCI-X-to-PCIe reverse bridges
* extended config space on the secondary side is only accessible
* if the bridge supports PCI-X Mode 2.
*/
pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
if (!pos)
return false;
pci_read_config_dword(bridge, pos + PCI_X_STATUS, &status);
return status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ);
}
static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
struct pci_dev *bridge, int busnr)
{
struct pci_bus *child;
int i;
int ret;
/* Allocate a new bus and inherit stuff from the parent */
child = pci_alloc_bus(parent);
if (!child)
return NULL;
child->parent = parent;
child->ops = parent->ops;
child->msi = parent->msi;
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.
*/
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->busn_res.start = busnr;
child->primary = parent->busn_res.start;
child->busn_res.end = 0xff;
if (!bridge) {
child->dev.parent = parent->bridge;
goto add_dev;
}
child->self = bridge;
child->bridge = get_device(&bridge->dev);
child->dev.parent = child->bridge;
pci_set_bus_of_node(child);
pci_set_bus_speed(child);
/*
* Check whether extended config space is accessible on the child
* bus. Note that we currently assume it is always accessible on
* the root bus.
*/
if (!pci_bridge_child_ext_cfg_accessible(bridge)) {
child->bus_flags |= PCI_BUS_FLAGS_NO_EXTCFG;
pci_info(child, "extended config space not accessible\n");
}
/* 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;
add_dev:
pci_set_bus_msi_domain(child);
ret = device_register(&child->dev);
WARN_ON(ret < 0);
pcibios_add_bus(child);
if (child->ops->add_bus) {
ret = child->ops->add_bus(child);
if (WARN_ON(ret < 0))
dev_err(&child->dev, "failed to add bus: %d\n", ret);
}
/* Create legacy_io and legacy_mem files for this bus */
pci_create_legacy_files(child);
return child;
}
struct pci_bus *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;
}
EXPORT_SYMBOL(pci_add_new_bus);
static void pci_enable_crs(struct pci_dev *pdev)
{
u16 root_cap = 0;
/* Enable CRS Software Visibility if supported */
pcie_capability_read_word(pdev, PCI_EXP_RTCAP, &root_cap);
if (root_cap & PCI_EXP_RTCAP_CRSVIS)
pcie_capability_set_word(pdev, PCI_EXP_RTCTL,
PCI_EXP_RTCTL_CRSSVE);
}
static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
unsigned int available_buses);
/**
* pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus
* numbers from EA capability.
* @dev: Bridge
* @sec: updated with secondary bus number from EA
* @sub: updated with subordinate bus number from EA
*
* If @dev is a bridge with EA capability that specifies valid secondary
* and subordinate bus numbers, return true with the bus numbers in @sec
* and @sub. Otherwise return false.
*/
static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub)
{
int ea, offset;
u32 dw;
u8 ea_sec, ea_sub;
if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
return false;
/* find PCI EA capability in list */
ea = pci_find_capability(dev, PCI_CAP_ID_EA);
if (!ea)
return false;
offset = ea + PCI_EA_FIRST_ENT;
pci_read_config_dword(dev, offset, &dw);
ea_sec = dw & PCI_EA_SEC_BUS_MASK;
ea_sub = (dw & PCI_EA_SUB_BUS_MASK) >> PCI_EA_SUB_BUS_SHIFT;
if (ea_sec == 0 || ea_sub < ea_sec)
return false;
*sec = ea_sec;
*sub = ea_sub;
return true;
}
/*
* pci_scan_bridge_extend() - Scan buses behind a bridge
* @bus: Parent bus the bridge is on
* @dev: Bridge itself
* @max: Starting subordinate number of buses behind this bridge
* @available_buses: Total number of buses available for this bridge and
* the devices below. After the minimal bus space has
* been allocated the remaining buses will be
* distributed equally between hotplug-capable bridges.
* @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
* that need to be reconfigured.
*
* 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.
*
* Return: New subordinate number covering all buses behind this bridge.
*/
static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
int max, unsigned int available_buses,
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;
bool fixed_buses;
u8 fixed_sec, fixed_sub;
int next_busnr;
/*
* Make sure the bridge is powered on to be able to access config
* space of devices below it.
*/
pm_runtime_get_sync(&dev->dev);
pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
primary = buses & 0xFF;
secondary = (buses >> 8) & 0xFF;
subordinate = (buses >> 16) & 0xFF;
pci_dbg(dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
secondary, subordinate, pass);
if (!primary && (primary != bus->number) && secondary && subordinate) {
pci_warn(dev, "Primary bus is hard wired to 0\n");
primary = bus->number;
}
/* Check if setup is sensible at all */
if (!pass &&
(primary != bus->number || secondary <= bus->number ||
secondary > subordinate)) {
pci_info(dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n",
secondary, subordinate);
broken = 1;
}
/*
* Disable Master-Abort Mode 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);
pci_enable_crs(dev);
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;
/*
* The bus might already exist for two reasons: Either we
* are rescanning the bus or the bus is reachable through
* more than one bridge. The second case can happen with
* the i450NX chipset.
*/
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;
pci_bus_insert_busn_res(child, secondary, subordinate);
child->bridge_ctl = bctl;
}
cmax = pci_scan_child_bus(child);
if (cmax > subordinate)
pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n",
subordinate, cmax);
/* Subordinate should equal child->busn_res.end */
if (subordinate > max)
max = 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 || is_cardbus)
/*
* 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);
/* Read bus numbers from EA Capability (if present) */
fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub);
if (fixed_buses)
next_busnr = fixed_sec;
else
next_busnr = max + 1;
/*
* Prevent assigning a bus number that already exists.
* This can happen when a bridge is hot-plugged, so in this
* case we only re-scan this bus.
*/
child = pci_find_bus(pci_domain_nr(bus), next_busnr);
if (!child) {
child = pci_add_new_bus(bus, dev, next_busnr);
if (!child)
goto out;
pci_bus_insert_busn_res(child, next_busnr,
bus->busn_res.end);
}
max++;
if (available_buses)
available_buses--;
buses = (buses & 0xff000000)
| ((unsigned int)(child->primary) << 0)
| ((unsigned int)(child->busn_res.start) << 8)
| ((unsigned int)(child->busn_res.end) << 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;
max = pci_scan_child_bus_extend(child, available_buses);
} 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->busn_res.end > max) &&
(parent->busn_res.end <= 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;
}
/*
* Set subordinate bus number to its real value.
* If fixed subordinate bus number exists from EA
* capability then use it.
*/
if (fixed_buses)
max = fixed_sub;
pci_bus_update_busn_res_end(child, 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);
/* Check that all devices are accessible */
while (bus->parent) {
if ((child->busn_res.end > bus->busn_res.end) ||
(child->number > bus->busn_res.end) ||
(child->number < bus->number) ||
(child->busn_res.end < bus->number)) {
dev_info(&dev->dev, "devices behind bridge are unusable because %pR cannot be assigned for them\n",
&child->busn_res);
break;
}
bus = bus->parent;
}
out:
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);
pm_runtime_put(&dev->dev);
return max;
}
/*
* pci_scan_bridge() - Scan buses behind a bridge
* @bus: Parent bus the bridge is on
* @dev: Bridge itself
* @max: Starting subordinate number of buses behind this bridge
* @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
* that need to be reconfigured.
*
* 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.
*
* Return: New subordinate number covering all buses behind this bridge.
*/
int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
{
return pci_scan_bridge_extend(bus, dev, max, 0, pass);
}
EXPORT_SYMBOL(pci_scan_bridge);
/*
* 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;
/* VFs are not allowed to use INTx, so skip the config reads */
if (dev->is_virtfn) {
dev->pin = 0;
dev->irq = 0;
return;
}
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;
int type;
struct pci_dev *parent;
pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
if (!pos)
return;
pdev->pcie_cap = pos;
pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
pdev->pcie_flags_reg = reg16;
pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
parent = pci_upstream_bridge(pdev);
if (!parent)
return;
/*
* Some systems do not identify their upstream/downstream ports
* correctly so detect impossible configurations here and correct
* the port type accordingly.
*/
type = pci_pcie_type(pdev);
if (type == PCI_EXP_TYPE_DOWNSTREAM) {
/*
* If pdev claims to be downstream port but the parent
* device is also downstream port assume pdev is actually
* upstream port.
*/
if (pcie_downstream_port(parent)) {
pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n");
pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM;
}
} else if (type == PCI_EXP_TYPE_UPSTREAM) {
/*
* If pdev claims to be upstream port but the parent
* device is also upstream port assume pdev is actually
* downstream port.
*/
if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) {
pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n");
pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM;
}
}
}
void set_pcie_hotplug_bridge(struct pci_dev *pdev)
{
u32 reg32;
pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32);
if (reg32 & PCI_EXP_SLTCAP_HPC)
pdev->is_hotplug_bridge = 1;
}
static void set_pcie_thunderbolt(struct pci_dev *dev)
{
int vsec = 0;
u32 header;
while ((vsec = pci_find_next_ext_capability(dev, vsec,
PCI_EXT_CAP_ID_VNDR))) {
pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header);
/* Is the device part of a Thunderbolt controller? */
if (dev->vendor == PCI_VENDOR_ID_INTEL &&
PCI_VNDR_HEADER_ID(header) == PCI_VSEC_ID_INTEL_TBT) {
dev->is_thunderbolt = 1;
return;
}
}
}
static void set_pcie_untrusted(struct pci_dev *dev)
{
struct pci_dev *parent;
/*
* If the upstream bridge is untrusted we treat this device
* untrusted as well.
*/
parent = pci_upstream_bridge(dev);
if (parent && parent->untrusted)
dev->untrusted = true;
}
/**
* pci_ext_cfg_is_aliased - Is ext config space just an alias of std config?
* @dev: PCI device
*
* PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that
* when forwarding a type1 configuration request the bridge must check that
* the extended register address field is zero. The bridge is not permitted
* to forward the transactions and must handle it as an Unsupported Request.
* Some bridges do not follow this rule and simply drop the extended register
* bits, resulting in the standard config space being aliased, every 256
* bytes across the entire configuration space. Test for this condition by
* comparing the first dword of each potential alias to the vendor/device ID.
* Known offenders:
* ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03)
* AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40)
*/
static bool pci_ext_cfg_is_aliased(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_QUIRKS
int pos;
u32 header, tmp;
pci_read_config_dword(dev, PCI_VENDOR_ID, &header);
for (pos = PCI_CFG_SPACE_SIZE;
pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) {
if (pci_read_config_dword(dev, pos, &tmp) != PCIBIOS_SUCCESSFUL
|| header != tmp)
return false;
}
return true;
#else
return false;
#endif
}
/**
* 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.
*/
static 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)
return PCI_CFG_SPACE_SIZE;
if (status == 0xffffffff || pci_ext_cfg_is_aliased(dev))
return PCI_CFG_SPACE_SIZE;
return PCI_CFG_SPACE_EXP_SIZE;
}
int pci_cfg_space_size(struct pci_dev *dev)
{
int pos;
u32 status;
u16 class;
#ifdef CONFIG_PCI_IOV
/*
* Per the SR-IOV specification (rev 1.1, sec 3.5), VFs are required to
* implement a PCIe capability and therefore must implement extended
* config space. We can skip the NO_EXTCFG test below and the
* reachability/aliasing test in pci_cfg_space_size_ext() by virtue of
* the fact that the SR-IOV capability on the PF resides in extended
* config space and must be accessible and non-aliased to have enabled
* support for this VF. This is a micro performance optimization for
* systems supporting many VFs.
*/
if (dev->is_virtfn)
return PCI_CFG_SPACE_EXP_SIZE;
#endif
if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG)
return PCI_CFG_SPACE_SIZE;
class = dev->class >> 8;
if (class == PCI_CLASS_BRIDGE_HOST)
return pci_cfg_space_size_ext(dev);
if (pci_is_pcie(dev))
return pci_cfg_space_size_ext(dev);
pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!pos)
return PCI_CFG_SPACE_SIZE;
pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
if (status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ))
return pci_cfg_space_size_ext(dev);
return PCI_CFG_SPACE_SIZE;
}
static u32 pci_class(struct pci_dev *dev)
{
u32 class;
#ifdef CONFIG_PCI_IOV
if (dev->is_virtfn)
return dev->physfn->sriov->class;
#endif
pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
return class;
}
static void pci_subsystem_ids(struct pci_dev *dev, u16 *vendor, u16 *device)
{
#ifdef CONFIG_PCI_IOV
if (dev->is_virtfn) {
*vendor = dev->physfn->sriov->subsystem_vendor;
*device = dev->physfn->sriov->subsystem_device;
return;
}
#endif
pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, vendor);
pci_read_config_word(dev, PCI_SUBSYSTEM_ID, device);
}
static u8 pci_hdr_type(struct pci_dev *dev)
{
u8 hdr_type;
#ifdef CONFIG_PCI_IOV
if (dev->is_virtfn)
return dev->physfn->sriov->hdr_type;
#endif
pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type);
return hdr_type;
}
#define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
static void pci_msi_setup_pci_dev(struct pci_dev *dev)
{
/*
* Disable the MSI hardware to avoid screaming interrupts
* during boot. This is the power on reset default so
* usually this should be a noop.
*/
dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (dev->msi_cap)
pci_msi_set_enable(dev, 0);
dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (dev->msix_cap)
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
}
/**
* pci_intx_mask_broken - Test PCI_COMMAND_INTX_DISABLE writability
* @dev: PCI device
*
* Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev. Check this
* at enumeration-time to avoid modifying PCI_COMMAND at run-time.
*/
static int pci_intx_mask_broken(struct pci_dev *dev)
{
u16 orig, toggle, new;
pci_read_config_word(dev, PCI_COMMAND, &orig);
toggle = orig ^ PCI_COMMAND_INTX_DISABLE;
pci_write_config_word(dev, PCI_COMMAND, toggle);
pci_read_config_word(dev, PCI_COMMAND, &new);
pci_write_config_word(dev, PCI_COMMAND, orig);
/*
* PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI
* r2.3, so strictly speaking, a device is not *broken* if it's not
* writable. But we'll live with the misnomer for now.
*/
if (new != toggle)
return 1;
return 0;
}
static void early_dump_pci_device(struct pci_dev *pdev)
{
u32 value[256 / 4];
int i;
pci_info(pdev, "config space:\n");
for (i = 0; i < 256; i += 4)
pci_read_config_dword(pdev, i, &value[i / 4]);
print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1,
value, 256, false);
}
/**
* 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;
u16 cmd;
u8 hdr_type;
int pos = 0;
struct pci_bus_region region;
struct resource *res;
hdr_type = pci_hdr_type(dev);
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);
pci_dev_assign_slot(dev);
/*
* 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));
class = pci_class(dev);
dev->revision = class & 0xff;
dev->class = class >> 8; /* upper 3 bytes */
pci_info(dev, "[%04x:%04x] type %02x class %#08x\n",
dev->vendor, dev->device, dev->hdr_type, dev->class);
if (pci_early_dump)
early_dump_pci_device(dev);
/* Need to have dev->class ready */
dev->cfg_size = pci_cfg_space_size(dev);
/* Need to have dev->cfg_size ready */
set_pcie_thunderbolt(dev);
set_pcie_untrusted(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;
if (dev->non_compliant_bars) {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
pci_info(dev, "device has non-compliant BARs; disabling IO/MEM decoding\n");
cmd &= ~PCI_COMMAND_IO;
cmd &= ~PCI_COMMAND_MEMORY;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
}
dev->broken_intx_masking = pci_intx_mask_broken(dev);
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_subsystem_ids(dev, &dev->subsystem_vendor, &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) {
region.start = 0x1F0;
region.end = 0x1F7;
res = &dev->resource[0];
res->flags = LEGACY_IO_RESOURCE;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, "legacy IDE quirk: reg 0x10: %pR\n",
res);
region.start = 0x3F6;
region.end = 0x3F6;
res = &dev->resource[1];
res->flags = LEGACY_IO_RESOURCE;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, "legacy IDE quirk: reg 0x14: %pR\n",
res);
}
if ((progif & 4) == 0) {
region.start = 0x170;
region.end = 0x177;
res = &dev->resource[2];
res->flags = LEGACY_IO_RESOURCE;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, "legacy IDE quirk: reg 0x18: %pR\n",
res);
region.start = 0x376;
region.end = 0x376;
res = &dev->resource[3];
res->flags = LEGACY_IO_RESOURCE;
pcibios_bus_to_resource(dev->bus, res, &region);
pci_info(dev, "legacy IDE quirk: reg 0x1c: %pR\n",
res);
}
}
break;
case PCI_HEADER_TYPE_BRIDGE: /* bridge header */
/*
* 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);
pci_read_bridge_windows(dev);
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 */
pci_err(dev, "unknown header type %02x, ignoring device\n",
dev->hdr_type);
return -EIO;
bad:
pci_err(dev, "ignoring class %#08x (doesn't match header type %02x)\n",
dev->class, dev->hdr_type);
dev->class = PCI_CLASS_NOT_DEFINED << 8;
}
/* We found a fine healthy device, go go go... */
return 0;
}
static void pci_configure_mps(struct pci_dev *dev)
{
struct pci_dev *bridge = pci_upstream_bridge(dev);
int mps, mpss, p_mps, rc;
if (!pci_is_pcie(dev) || !bridge || !pci_is_pcie(bridge))
return;
/* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */
if (dev->is_virtfn)
return;
mps = pcie_get_mps(dev);
p_mps = pcie_get_mps(bridge);
if (mps == p_mps)
return;
if (pcie_bus_config == PCIE_BUS_TUNE_OFF) {
pci_warn(dev, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
mps, pci_name(bridge), p_mps);
return;
}
/*
* Fancier MPS configuration is done later by
* pcie_bus_configure_settings()
*/
if (pcie_bus_config != PCIE_BUS_DEFAULT)
return;
mpss = 128 << dev->pcie_mpss;
if (mpss < p_mps && pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) {
pcie_set_mps(bridge, mpss);
pci_info(dev, "Upstream bridge's Max Payload Size set to %d (was %d, max %d)\n",
mpss, p_mps, 128 << bridge->pcie_mpss);
p_mps = pcie_get_mps(bridge);
}
rc = pcie_set_mps(dev, p_mps);
if (rc) {
pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
p_mps);
return;
}
pci_info(dev, "Max Payload Size set to %d (was %d, max %d)\n",
p_mps, mps, mpss);
}
int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
{
struct pci_host_bridge *host;
u32 cap;
u16 ctl;
int ret;
if (!pci_is_pcie(dev))
return 0;
ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
if (ret)
return 0;
if (!(cap & PCI_EXP_DEVCAP_EXT_TAG))
return 0;
ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
if (ret)
return 0;
host = pci_find_host_bridge(dev->bus);
if (!host)
return 0;
/*
* If some device in the hierarchy doesn't handle Extended Tags
* correctly, make sure they're disabled.
*/
if (host->no_ext_tags) {
if (ctl & PCI_EXP_DEVCTL_EXT_TAG) {
pci_info(dev, "disabling Extended Tags\n");
pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_EXT_TAG);
}
return 0;
}
if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) {
pci_info(dev, "enabling Extended Tags\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_EXT_TAG);
}
return 0;
}
/**
* pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable
* @dev: PCI device to query
*
* Returns true if the device has enabled relaxed ordering attribute.
*/
bool pcie_relaxed_ordering_enabled(struct pci_dev *dev)
{
u16 v;
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v);
return !!(v & PCI_EXP_DEVCTL_RELAX_EN);
}
EXPORT_SYMBOL(pcie_relaxed_ordering_enabled);
static void pci_configure_relaxed_ordering(struct pci_dev *dev)
{
struct pci_dev *root;
/* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */
if (dev->is_virtfn)
return;
if (!pcie_relaxed_ordering_enabled(dev))
return;
/*
* For now, we only deal with Relaxed Ordering issues with Root
* Ports. Peer-to-Peer DMA is another can of worms.
*/
root = pci_find_pcie_root_port(dev);
if (!root)
return;
if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) {
pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_RELAX_EN);
pci_info(dev, "Relaxed Ordering disabled because the Root Port didn't support it\n");
}
}
static void pci_configure_ltr(struct pci_dev *dev)
{
#ifdef CONFIG_PCIEASPM
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
struct pci_dev *bridge;
u32 cap, ctl;
if (!pci_is_pcie(dev))
return;
pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_LTR))
return;
pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl);
if (ctl & PCI_EXP_DEVCTL2_LTR_EN) {
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
dev->ltr_path = 1;
return;
}
bridge = pci_upstream_bridge(dev);
if (bridge && bridge->ltr_path)
dev->ltr_path = 1;
return;
}
if (!host->native_ltr)
return;
/*
* Software must not enable LTR in an Endpoint unless the Root
* Complex and all intermediate Switches indicate support for LTR.
* PCIe r4.0, sec 6.18.
*/
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
((bridge = pci_upstream_bridge(dev)) &&
bridge->ltr_path)) {
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_LTR_EN);
dev->ltr_path = 1;
}
#endif
}
static void pci_configure_eetlp_prefix(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_PASID
struct pci_dev *bridge;
int pcie_type;
u32 cap;
if (!pci_is_pcie(dev))
return;
pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_EE_PREFIX))
return;
pcie_type = pci_pcie_type(dev);
if (pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
pcie_type == PCI_EXP_TYPE_RC_END)
dev->eetlp_prefix_path = 1;
else {
bridge = pci_upstream_bridge(dev);
if (bridge && bridge->eetlp_prefix_path)
dev->eetlp_prefix_path = 1;
}
#endif
}
static void pci_configure_serr(struct pci_dev *dev)
{
u16 control;
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
/*
* A bridge will not forward ERR_ messages coming from an
* endpoint unless SERR# forwarding is enabled.
*/
pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control);
if (!(control & PCI_BRIDGE_CTL_SERR)) {
control |= PCI_BRIDGE_CTL_SERR;
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control);
}
}
}
static void pci_configure_device(struct pci_dev *dev)
{
pci_configure_mps(dev);
pci_configure_extended_tags(dev, NULL);
pci_configure_relaxed_ordering(dev);
pci_configure_ltr(dev);
pci_configure_eetlp_prefix(dev);
pci_configure_serr(dev);
pci_acpi_program_hp_params(dev);
}
static void pci_release_capabilities(struct pci_dev *dev)
{
pci_aer_exit(dev);
pci_vpd_release(dev);
pci_iov_release(dev);
pci_free_cap_save_buffers(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);
pci_release_of_node(pci_dev);
pcibios_release_device(pci_dev);
pci_bus_put(pci_dev->bus);
kfree(pci_dev->driver_override);
bitmap_free(pci_dev->dma_alias_mask);
kfree(pci_dev);
}
struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
{
struct pci_dev *dev;
dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
if (!dev)
return NULL;
INIT_LIST_HEAD(&dev->bus_list);
dev->dev.type = &pci_dev_type;
dev->bus = pci_bus_get(bus);
return dev;
}
EXPORT_SYMBOL(pci_alloc_dev);
static bool pci_bus_crs_vendor_id(u32 l)
{
return (l & 0xffff) == 0x0001;
}
static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l,
int timeout)
{
int delay = 1;
if (!pci_bus_crs_vendor_id(*l))
return true; /* not a CRS completion */
if (!timeout)
return false; /* CRS, but caller doesn't want to wait */
/*
* We got the reserved Vendor ID that indicates a completion with
* Configuration Request Retry Status (CRS). Retry until we get a
* valid Vendor ID or we time out.
*/
while (pci_bus_crs_vendor_id(*l)) {
if (delay > timeout) {
pr_warn("pci %04x:%02x:%02x.%d: not ready after %dms; giving up\n",
pci_domain_nr(bus), bus->number,
PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1);
return false;
}
if (delay >= 1000)
pr_info("pci %04x:%02x:%02x.%d: not ready after %dms; waiting\n",
pci_domain_nr(bus), bus->number,
PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1);
msleep(delay);
delay *= 2;
if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
return false;
}
if (delay >= 1000)
pr_info("pci %04x:%02x:%02x.%d: ready after %dms\n",
pci_domain_nr(bus), bus->number,
PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1);
return true;
}
bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
int timeout)
{
if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
return false;
/* Some broken boards return 0 or ~0 if a slot is empty: */
if (*l == 0xffffffff || *l == 0x00000000 ||
*l == 0x0000ffff || *l == 0xffff0000)
return false;
if (pci_bus_crs_vendor_id(*l))
return pci_bus_wait_crs(bus, devfn, l, timeout);
return true;
}
bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
int timeout)
{
#ifdef CONFIG_PCI_QUIRKS
struct pci_dev *bridge = bus->self;
/*
* Certain IDT switches have an issue where they improperly trigger
* ACS Source Validation errors on completions for config reads.
*/
if (bridge && bridge->vendor == PCI_VENDOR_ID_IDT &&
bridge->device == 0x80b5)
return pci_idt_bus_quirk(bus, devfn, l, timeout);
#endif
return pci_bus_generic_read_dev_vendor_id(bus, devfn, l, timeout);
}
EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);
/*
* 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;
if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))
return NULL;
dev = pci_alloc_dev(bus);
if (!dev)
return NULL;
dev->devfn = devfn;
dev->vendor = l & 0xffff;
dev->device = (l >> 16) & 0xffff;
pci_set_of_node(dev);
if (pci_setup_device(dev)) {
pci_bus_put(dev->bus);
kfree(dev);
return NULL;
}
return dev;
}
void pcie_report_downtraining(struct pci_dev *dev)
{
if (!pci_is_pcie(dev))
return;
/* Look from the device up to avoid downstream ports with no devices */
if ((pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) &&
(pci_pcie_type(dev) != PCI_EXP_TYPE_LEG_END) &&
(pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM))
return;
/* Multi-function PCIe devices share the same link/status */
if (PCI_FUNC(dev->devfn) != 0 || dev->is_virtfn)
return;
/* Print link status only if the device is constrained by the fabric */
__pcie_print_link_status(dev, false);
}
static void pci_init_capabilities(struct pci_dev *dev)
{
pci_ea_init(dev); /* Enhanced Allocation */
/* Setup MSI caps & disable MSI/MSI-X interrupts */
pci_msi_setup_pci_dev(dev);
/* Buffers for saving PCIe and PCI-X capabilities */
pci_allocate_cap_save_buffers(dev);
pci_pm_init(dev); /* Power Management */
pci_vpd_init(dev); /* Vital Product Data */
pci_configure_ari(dev); /* Alternative Routing-ID Forwarding */
pci_iov_init(dev); /* Single Root I/O Virtualization */
pci_ats_init(dev); /* Address Translation Services */
pci_pri_init(dev); /* Page Request Interface */
pci_pasid_init(dev); /* Process Address Space ID */
pci_enable_acs(dev); /* Enable ACS P2P upstream forwarding */
pci_ptm_init(dev); /* Precision Time Measurement */
pci_aer_init(dev); /* Advanced Error Reporting */
pcie_report_downtraining(dev);
if (pci_probe_reset_function(dev) == 0)
dev->reset_fn = 1;
}
/*
* This is the equivalent of pci_host_bridge_msi_domain() that acts on
* devices. Firmware interfaces that can select the MSI domain on a
* per-device basis should be called from here.
*/
static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev)
{
struct irq_domain *d;
/*
* If a domain has been set through the pcibios_add_device()
* callback, then this is the one (platform code knows best).
*/
d = dev_get_msi_domain(&dev->dev);
if (d)
return d;
/*
* Let's see if we have a firmware interface able to provide
* the domain.
*/
d = pci_msi_get_device_domain(dev);
if (d)
return d;
return NULL;
}
static void pci_set_msi_domain(struct pci_dev *dev)
{
struct irq_domain *d;
/*
* If the platform or firmware interfaces cannot supply a
* device-specific MSI domain, then inherit the default domain
* from the host bridge itself.
*/
d = pci_dev_msi_domain(dev);
if (!d)
d = dev_get_msi_domain(&dev->bus->dev);
dev_set_msi_domain(&dev->dev, d);
}
void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
{
int ret;
pci_configure_device(dev);
device_initialize(&dev->dev);
dev->dev.release = pci_release_dev;
set_dev_node(&dev->dev, pcibus_to_node(bus));
dev->dev.dma_mask = &dev->dma_mask;
dev->dev.dma_parms = &dev->dma_parms;
dev->dev.coherent_dma_mask = 0xffffffffull;
dma_set_max_seg_size(&dev->dev, 65536);
dma_set_seg_boundary(&dev->dev, 0xffffffff);
/* Fix up broken headers */
pci_fixup_device(pci_fixup_header, dev);
pci_reassigndev_resource_alignment(dev);
dev->state_saved = false;
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);
ret = pcibios_add_device(dev);
WARN_ON(ret < 0);
/* Set up MSI IRQ domain */
pci_set_msi_domain(dev);
/* Notifier could use PCI capabilities */
dev->match_driver = false;
ret = device_add(&dev->dev);
WARN_ON(ret < 0);
}
struct pci_dev *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_fn(struct pci_bus *bus, struct pci_dev *dev, unsigned fn)
{
int pos;
u16 cap = 0;
unsigned next_fn;
if (pci_ari_enabled(bus)) {
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 + PCI_ARI_CAP, &cap);
next_fn = PCI_ARI_CAP_NFN(cap);
if (next_fn <= fn)
return 0; /* protect against malformed list */
return next_fn;
}
/* dev may be NULL for non-contiguous multifunction devices */
if (!dev || dev->multifunction)
return (fn + 1) % 8;
return 0;
}
static int only_one_child(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
/*
* Systems with unusual topologies set PCI_SCAN_ALL_PCIE_DEVS so
* we scan for all possible devices, not just Device 0.
*/
if (pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS))
return 0;
/*
* A PCIe Downstream Port normally leads to a Link with only Device
* 0 on it (PCIe spec r3.1, sec 7.3.1). As an optimization, scan
* only for Device 0 in that situation.
*/
if (bridge && pci_is_pcie(bridge) && pcie_downstream_port(bridge))
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;
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 (!pci_dev_is_added(dev))
nr++;
for (fn = next_fn(bus, dev, 0); fn > 0; fn = next_fn(bus, dev, fn)) {
dev = pci_scan_single_device(bus, devfn + fn);
if (dev) {
if (!pci_dev_is_added(dev))
nr++;
dev->multifunction = 1;
}
}
/* Only one slot has PCIe device */
if (bus->self && nr)
pcie_aspm_init_link_state(bus->self);
return nr;
}
EXPORT_SYMBOL(pci_scan_slot);
static int pcie_find_smpss(struct pci_dev *dev, void *data)
{
u8 *smpss = data;
if (!pci_is_pcie(dev))
return 0;
/*
* We don't have a way to change MPS settings on devices that have
* drivers attached. A hot-added device might support only the minimum
* MPS setting (MPS=128). Therefore, if the fabric contains a bridge
* where devices may be hot-added, we limit the fabric MPS to 128 so
* hot-added devices will work correctly.
*
* However, if we hot-add a device to a slot directly below a Root
* Port, it's impossible for there to be other existing devices below
* the port. We don't limit the MPS in this case because we can
* reconfigure MPS on both the Root Port and the hot-added device,
* and there are no other devices involved.
*
* Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA.
*/
if (dev->is_hotplug_bridge &&
pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
*smpss = 0;
if (*smpss > dev->pcie_mpss)
*smpss = dev->pcie_mpss;
return 0;
}
static void pcie_write_mps(struct pci_dev *dev, int mps)
{
int rc;
if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
mps = 128 << dev->pcie_mpss;
if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT &&
dev->bus->self)
/*
* For "Performance", the assumption is made that
* downstream communication will never be larger than
* the MRRS. So, the MPS only needs to be configured
* for the upstream communication. This being the case,
* walk from the top down and set the MPS of the child
* to that of the parent bus.
*
* Configure the device MPS with the smaller of the
* device MPSS or the bridge MPS (which is assumed to be
* properly configured at this point to the largest
* allowable MPS based on its parent bus).
*/
mps = min(mps, pcie_get_mps(dev->bus->self));
}
rc = pcie_set_mps(dev, mps);
if (rc)
pci_err(dev, "Failed attempting to set the MPS\n");
}
static void pcie_write_mrrs(struct pci_dev *dev)
{
int rc, mrrs;
/*
* In the "safe" case, do not configure the MRRS. There appear to be
* issues with setting MRRS to 0 on a number of devices.
*/
if (pcie_bus_config != PCIE_BUS_PERFORMANCE)
return;
/*
* For max performance, the MRRS must be set to the largest supported
* value. However, it cannot be configured larger than the MPS the
* device or the bus can support. This should already be properly
* configured by a prior call to pcie_write_mps().
*/
mrrs = pcie_get_mps(dev);
/*
* MRRS is a R/W register. Invalid values can be written, but a
* subsequent read will verify if the value is acceptable or not.
* If the MRRS value provided is not acceptable (e.g., too large),
* shrink the value until it is acceptable to the HW.
*/
while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
rc = pcie_set_readrq(dev, mrrs);
if (!rc)
break;
pci_warn(dev, "Failed attempting to set the MRRS\n");
mrrs /= 2;
}
if (mrrs < 128)
pci_err(dev, "MRRS was unable to be configured with a safe value. If problems are experienced, try running with pci=pcie_bus_safe\n");
}
static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
{
int mps, orig_mps;
if (!pci_is_pcie(dev))
return 0;
if (pcie_bus_config == PCIE_BUS_TUNE_OFF ||
pcie_bus_config == PCIE_BUS_DEFAULT)
return 0;
mps = 128 << *(u8 *)data;
orig_mps = pcie_get_mps(dev);
pcie_write_mps(dev, mps);
pcie_write_mrrs(dev);
pci_info(dev, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n",
pcie_get_mps(dev), 128 << dev->pcie_mpss,
orig_mps, pcie_get_readrq(dev));
return 0;
}
/*
* pcie_bus_configure_settings() requires that pci_walk_bus work in a top-down,
* parents then children fashion. If this changes, then this code will not
* work as designed.
*/
void pcie_bus_configure_settings(struct pci_bus *bus)
{
u8 smpss = 0;
if (!bus->self)
return;
if (!pci_is_pcie(bus->self))
return;
/*
* FIXME - Peer to peer DMA is possible, though the endpoint would need
* to be aware of the MPS of the destination. To work around this,
* simply force the MPS of the entire system to the smallest possible.
*/
if (pcie_bus_config == PCIE_BUS_PEER2PEER)
smpss = 0;
if (pcie_bus_config == PCIE_BUS_SAFE) {
smpss = bus->self->pcie_mpss;
pcie_find_smpss(bus->self, &smpss);
pci_walk_bus(bus, pcie_find_smpss, &smpss);
}
pcie_bus_configure_set(bus->self, &smpss);
pci_walk_bus(bus, pcie_bus_configure_set, &smpss);
}
EXPORT_SYMBOL_GPL(pcie_bus_configure_settings);
/*
* Called after each bus is probed, but before its children are examined. This
* is marked as __weak because multiple architectures define it.
*/
void __weak pcibios_fixup_bus(struct pci_bus *bus)
{
/* nothing to do, expected to be removed in the future */
}
/**
* pci_scan_child_bus_extend() - Scan devices below a bus
* @bus: Bus to scan for devices
* @available_buses: Total number of buses available (%0 does not try to
* extend beyond the minimal)
*
* Scans devices below @bus including subordinate buses. Returns new
* subordinate number including all the found devices. Passing
* @available_buses causes the remaining bus space to be distributed
* equally between hotplug-capable bridges to allow future extension of the
* hierarchy.
*/
static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
unsigned int available_buses)
{
unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0;
unsigned int start = bus->busn_res.start;
unsigned int devfn, fn, cmax, max = start;
struct pci_dev *dev;
int nr_devs;
dev_dbg(&bus->dev, "scanning bus\n");
/* Go find them, Rover! */
for (devfn = 0; devfn < 256; devfn += 8) {
nr_devs = pci_scan_slot(bus, devfn);
/*
* The Jailhouse hypervisor may pass individual functions of a
* multi-function device to a guest without passing function 0.
* Look for them as well.
*/
if (jailhouse_paravirt() && nr_devs == 0) {
for (fn = 1; fn < 8; fn++) {
dev = pci_scan_single_device(bus, devfn + fn);
if (dev)
dev->multifunction = 1;
}
}
}
/* Reserve buses for SR-IOV capability */
used_buses = pci_iov_bus_range(bus);
max += used_buses;
/*
* 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);
bus->is_added = 1;
}
/*
* Calculate how many hotplug bridges and normal bridges there
* are on this bus. We will distribute the additional available
* buses between hotplug bridges.
*/
for_each_pci_bridge(dev, bus) {
if (dev->is_hotplug_bridge)
hotplug_bridges++;
else
normal_bridges++;
}
/*
* Scan bridges that are already configured. We don't touch them
* unless they are misconfigured (which will be done in the second
* scan below).
*/
for_each_pci_bridge(dev, bus) {
cmax = max;
max = pci_scan_bridge_extend(bus, dev, max, 0, 0);
/*
* Reserve one bus for each bridge now to avoid extending
* hotplug bridges too much during the second scan below.
*/
used_buses++;
if (cmax - max > 1)
used_buses += cmax - max - 1;
}
/* Scan bridges that need to be reconfigured */
for_each_pci_bridge(dev, bus) {
unsigned int buses = 0;
if (!hotplug_bridges && normal_bridges == 1) {
/*
* There is only one bridge on the bus (upstream
* port) so it gets all available buses which it
* can then distribute to the possible hotplug
* bridges below.
*/
buses = available_buses;
} else if (dev->is_hotplug_bridge) {
/*
* Distribute the extra buses between hotplug
* bridges if any.
*/
buses = available_buses / hotplug_bridges;
buses = min(buses, available_buses - used_buses + 1);
}
cmax = max;
max = pci_scan_bridge_extend(bus, dev, cmax, buses, 1);
/* One bus is already accounted so don't add it again */
if (max - cmax > 1)
used_buses += max - cmax - 1;
}
/*
* Make sure a hotplug bridge has at least the minimum requested
* number of buses but allow it to grow up to the maximum available
* bus number of there is room.
*/
if (bus->self && bus->self->is_hotplug_bridge) {
used_buses = max_t(unsigned int, available_buses,
pci_hotplug_bus_size - 1);
if (max - start < used_buses) {
max = start + used_buses;
/* Do not allocate more buses than we have room left */
if (max > bus->busn_res.end)
max = bus->busn_res.end;
dev_dbg(&bus->dev, "%pR extended by %#02x\n",
&bus->busn_res, max - start);
}
}
/*
* 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;
}
/**
* pci_scan_child_bus() - Scan devices below a bus
* @bus: Bus to scan for devices
*
* Scans devices below @bus including subordinate buses. Returns new
* subordinate number including all the found devices.
*/
unsigned int pci_scan_child_bus(struct pci_bus *bus)
{
return pci_scan_child_bus_extend(bus, 0);
}
EXPORT_SYMBOL_GPL(pci_scan_child_bus);
/**
* pcibios_root_bridge_prepare - Platform-specific host bridge setup
* @bridge: Host bridge to set up
*
* Default empty implementation. Replace with an architecture-specific setup
* routine, if necessary.
*/
int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
return 0;
}
void __weak pcibios_add_bus(struct pci_bus *bus)
{
}
void __weak pcibios_remove_bus(struct pci_bus *bus)
{
}
struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
int error;
struct pci_host_bridge *bridge;
bridge = pci_alloc_host_bridge(0);
if (!bridge)
return NULL;
bridge->dev.parent = parent;
list_splice_init(resources, &bridge->windows);
bridge->sysdata = sysdata;
bridge->busnr = bus;
bridge->ops = ops;
error = pci_register_host_bridge(bridge);
if (error < 0)
goto err_out;
return bridge->bus;
err_out:
kfree(bridge);
return NULL;
}
EXPORT_SYMBOL_GPL(pci_create_root_bus);
int pci_host_probe(struct pci_host_bridge *bridge)
{
struct pci_bus *bus, *child;
int ret;
ret = pci_scan_root_bus_bridge(bridge);
if (ret < 0) {
dev_err(bridge->dev.parent, "Scanning root bridge failed");
return ret;
}
bus = bridge->bus;
/*
* We insert PCI resources into the iomem_resource and
* ioport_resource trees in either pci_bus_claim_resources()
* or pci_bus_assign_resources().
*/
if (pci_has_flag(PCI_PROBE_ONLY)) {
pci_bus_claim_resources(bus);
} else {
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child);
}
pci_bus_add_devices(bus);
return 0;
}
EXPORT_SYMBOL_GPL(pci_host_probe);
int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
{
struct resource *res = &b->busn_res;
struct resource *parent_res, *conflict;
res->start = bus;
res->end = bus_max;
res->flags = IORESOURCE_BUS;
if (!pci_is_root_bus(b))
parent_res = &b->parent->busn_res;
else {
parent_res = get_pci_domain_busn_res(pci_domain_nr(b));
res->flags |= IORESOURCE_PCI_FIXED;
}
conflict = request_resource_conflict(parent_res, res);
if (conflict)
dev_info(&b->dev,
"busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n",
res, pci_is_root_bus(b) ? "domain " : "",
parent_res, conflict->name, conflict);
return conflict == NULL;
}
int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max)
{
struct resource *res = &b->busn_res;
struct resource old_res = *res;
resource_size_t size;
int ret;
if (res->start > bus_max)
return -EINVAL;
size = bus_max - res->start + 1;
ret = adjust_resource(res, res->start, size);
dev_info(&b->dev, "busn_res: %pR end %s updated to %02x\n",
&old_res, ret ? "can not be" : "is", bus_max);
if (!ret && !res->parent)
pci_bus_insert_busn_res(b, res->start, res->end);
return ret;
}
void pci_bus_release_busn_res(struct pci_bus *b)
{
struct resource *res = &b->busn_res;
int ret;
if (!res->flags || !res->parent)
return;
ret = release_resource(res);
dev_info(&b->dev, "busn_res: %pR %s released\n",
res, ret ? "can not be" : "is");
}
int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge)
{
struct resource_entry *window;
bool found = false;
struct pci_bus *b;
int max, bus, ret;
if (!bridge)
return -EINVAL;
resource_list_for_each_entry(window, &bridge->windows)
if (window->res->flags & IORESOURCE_BUS) {
found = true;
break;
}
ret = pci_register_host_bridge(bridge);
if (ret < 0)
return ret;
b = bridge->bus;
bus = bridge->busnr;
if (!found) {
dev_info(&b->dev,
"No busn resource found for root bus, will use [bus %02x-ff]\n",
bus);
pci_bus_insert_busn_res(b, bus, 255);
}
max = pci_scan_child_bus(b);
if (!found)
pci_bus_update_busn_res_end(b, max);
return 0;
}
EXPORT_SYMBOL(pci_scan_root_bus_bridge);
struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
struct resource_entry *window;
bool found = false;
struct pci_bus *b;
int max;
resource_list_for_each_entry(window, resources)
if (window->res->flags & IORESOURCE_BUS) {
found = true;
break;
}
b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
if (!b)
return NULL;
if (!found) {
dev_info(&b->dev,
"No busn resource found for root bus, will use [bus %02x-ff]\n",
bus);
pci_bus_insert_busn_res(b, bus, 255);
}
max = pci_scan_child_bus(b);
if (!found)
pci_bus_update_busn_res_end(b, max);
return b;
}
EXPORT_SYMBOL(pci_scan_root_bus);
struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
void *sysdata)
{
LIST_HEAD(resources);
struct pci_bus *b;
pci_add_resource(&resources, &ioport_resource);
pci_add_resource(&resources, &iomem_resource);
pci_add_resource(&resources, &busn_resource);
b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
if (b) {
pci_scan_child_bus(b);
} else {
pci_free_resource_list(&resources);
}
return b;
}
EXPORT_SYMBOL(pci_scan_bus);
/**
* pci_rescan_bus_bridge_resize - Scan a PCI bus for devices
* @bridge: PCI bridge for the bus to scan
*
* Scan a PCI bus and child buses for new devices, add them,
* and enable them, resizing bridge mmio/io resource if necessary
* and possible. The caller must ensure the child devices are already
* removed for resizing to occur.
*
* Returns the max number of subordinate bus discovered.
*/
unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge)
{
unsigned int max;
struct pci_bus *bus = bridge->subordinate;
max = pci_scan_child_bus(bus);
pci_assign_unassigned_bridge_resources(bridge);
pci_bus_add_devices(bus);
return max;
}
/**
* pci_rescan_bus - Scan a PCI bus for devices
* @bus: PCI bus to scan
*
* Scan a PCI bus and child buses for new devices, add them,
* and enable them.
*
* Returns the max number of subordinate bus discovered.
*/
unsigned int pci_rescan_bus(struct pci_bus *bus)
{
unsigned int max;
max = pci_scan_child_bus(bus);
pci_assign_unassigned_bus_resources(bus);
pci_bus_add_devices(bus);
return max;
}
EXPORT_SYMBOL_GPL(pci_rescan_bus);
/*
* pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal
* routines should always be executed under this mutex.
*/
static DEFINE_MUTEX(pci_rescan_remove_lock);
void pci_lock_rescan_remove(void)
{
mutex_lock(&pci_rescan_remove_lock);
}
EXPORT_SYMBOL_GPL(pci_lock_rescan_remove);
void pci_unlock_rescan_remove(void)
{
mutex_unlock(&pci_rescan_remove_lock);
}
EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove);
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);
}
int pci_hp_add_bridge(struct pci_dev *dev)
{
struct pci_bus *parent = dev->bus;
int busnr, start = parent->busn_res.start;
unsigned int available_buses = 0;
int end = parent->busn_res.end;
for (busnr = start; busnr <= end; busnr++) {
if (!pci_find_bus(pci_domain_nr(parent), busnr))
break;
}
if (busnr-- > end) {
pci_err(dev, "No bus number available for hot-added bridge\n");
return -1;
}
/* Scan bridges that are already configured */
busnr = pci_scan_bridge(parent, dev, busnr, 0);
/*
* Distribute the available bus numbers between hotplug-capable
* bridges to make extending the chain later possible.
*/
available_buses = end - busnr;
/* Scan bridges that need to be reconfigured */
pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1);
if (!dev->subordinate)
return -1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_hp_add_bridge);
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