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linux/drivers/pci/probe.c
Pali Rohár c14f7ccc9f PCI: Assign PCI domain IDs by ida_alloc() 
Replace assignment of PCI domain IDs from atomic_inc_return() to
ida_alloc().

Use two IDAs, one for static domain allocations (those which are defined in
device tree) and second for dynamic allocations (all other).

During removal of root bus / host bridge, also release the domain ID.  The
released ID can be reused again, for example when dynamically loading and
unloading native PCI host bridge drivers.

This change also allows to mix static device tree assignment and dynamic by
kernel as all static allocations are reserved in dynamic pool.

[bhelgaas: set "err" if "bus->domain_nr < 0"]
Link: https://lore.kernel.org/r/20220714184130.5436-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2022-11-08 11:14:18 -06:00

3361 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 <linux/bitfield.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 (PCI_POSSIBLE_ERROR(sz))
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 (PCI_POSSIBLE_ERROR(l))
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 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);
kfree(bridge);
}
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;
bridge->native_dpc = 1;
bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET;
device_initialize(&bridge->dev);
}
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);
static void devm_pci_alloc_host_bridge_release(void *data)
{
pci_free_host_bridge(data);
}
struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,
size_t priv)
{
int ret;
struct pci_host_bridge *bridge;
bridge = pci_alloc_host_bridge(priv);
if (!bridge)
return NULL;
bridge->dev.parent = dev;
ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release,
bridge);
if (ret)
return NULL;
ret = devm_of_pci_bridge_init(dev, bridge);
if (ret)
return NULL;
return bridge;
}
EXPORT_SYMBOL(devm_pci_alloc_host_bridge);
void pci_free_host_bridge(struct pci_host_bridge *bridge)
{
put_device(&bridge->dev);
}
EXPORT_SYMBOL(pci_free_host_bridge);
/* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */
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 */
};
/* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */
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 */
PCIE_SPEED_64_0GT, /* 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 */
};
EXPORT_SYMBOL_GPL(pcie_link_speed);
const char *pci_speed_string(enum pci_bus_speed speed)
{
/* Indexed by the pci_bus_speed enum */
static const char *speed_strings[] = {
"33 MHz PCI", /* 0x00 */
"66 MHz PCI", /* 0x01 */
"66 MHz PCI-X", /* 0x02 */
"100 MHz PCI-X", /* 0x03 */
"133 MHz PCI-X", /* 0x04 */
NULL, /* 0x05 */
NULL, /* 0x06 */
NULL, /* 0x07 */
NULL, /* 0x08 */
"66 MHz PCI-X 266", /* 0x09 */
"100 MHz PCI-X 266", /* 0x0a */
"133 MHz PCI-X 266", /* 0x0b */
"Unknown AGP", /* 0x0c */
"1x AGP", /* 0x0d */
"2x AGP", /* 0x0e */
"4x AGP", /* 0x0f */
"8x AGP", /* 0x10 */
"66 MHz PCI-X 533", /* 0x11 */
"100 MHz PCI-X 533", /* 0x12 */
"133 MHz PCI-X 533", /* 0x13 */
"2.5 GT/s PCIe", /* 0x14 */
"5.0 GT/s PCIe", /* 0x15 */
"8.0 GT/s PCIe", /* 0x16 */
"16.0 GT/s PCIe", /* 0x17 */
"32.0 GT/s PCIe", /* 0x18 */
"64.0 GT/s PCIe", /* 0x19 */
};
if (speed < ARRAY_SIZE(speed_strings))
return speed_strings[speed];
return "Unknown";
}
EXPORT_SYMBOL_GPL(pci_speed_string);
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;
/* If the host bridge driver sets a MSI domain of the bridge, use it */
d = dev_get_msi_domain(bus->bridge);
/*
* Any firmware interface that can resolve the msi_domain
* should be called from here.
*/
if (!d)
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, *next, *n;
struct pci_bus *bus, *b;
resource_size_t offset, next_offset;
LIST_HEAD(resources);
struct resource *res, *next_res;
char addr[64], *fmt;
const char *name;
int err;
bus = pci_alloc_bus(NULL);
if (!bus)
return -ENOMEM;
bridge->bus = bus;
bus->sysdata = bridge->sysdata;
bus->ops = bridge->ops;
bus->number = bus->busn_res.start = bridge->busnr;
#ifdef CONFIG_PCI_DOMAINS_GENERIC
if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET)
bus->domain_nr = pci_bus_find_domain_nr(bus, parent);
else
bus->domain_nr = bridge->domain_nr;
if (bus->domain_nr < 0) {
err = bus->domain_nr;
goto free;
}
#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;
/* Temporarily move resources off the list */
list_splice_init(&bridge->windows, &resources);
err = device_add(&bridge->dev);
if (err) {
put_device(&bridge->dev);
goto free;
}
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 (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) &&
!pci_host_of_has_msi_map(parent))
bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
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);
if (bus->ops->add_bus) {
err = bus->ops->add_bus(bus);
if (WARN_ON(err < 0))
dev_err(&bus->dev, "failed to add bus: %d\n", err);
}
/* 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");
/* Coalesce contiguous windows */
resource_list_for_each_entry_safe(window, n, &resources) {
if (list_is_last(&window->node, &resources))
break;
next = list_next_entry(window, node);
offset = window->offset;
res = window->res;
next_offset = next->offset;
next_res = next->res;
if (res->flags != next_res->flags || offset != next_offset)
continue;
if (res->end + 1 == next_res->start) {
next_res->start = res->start;
res->flags = res->start = res->end = 0;
}
}
/* Add initial resources to the bus */
resource_list_for_each_entry_safe(window, n, &resources) {
offset = window->offset;
res = window->res;
if (!res->end)
continue;
list_move_tail(&window->node, &bridge->windows);
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_del(&bridge->dev);
free:
#ifdef CONFIG_PCI_DOMAINS_GENERIC
pci_bus_release_domain_nr(bus, parent);
#endif
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;
struct pci_host_bridge *host;
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->sysdata = parent->sysdata;
child->bus_flags = parent->bus_flags;
host = pci_find_host_bridge(parent);
if (host->child_ops)
child->ops = host->child_ops;
else
child->ops = parent->ops;
/*
* 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, buses;
/*
* 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;
}
buses = subordinate - secondary;
cmax = pci_scan_child_bus_extend(child, buses);
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_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap);
pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);
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)
{
u16 vsec;
/* Is the device part of a Thunderbolt controller? */
vsec = pci_find_vsec_capability(dev, PCI_VENDOR_ID_INTEL, PCI_VSEC_ID_INTEL_TBT);
if (vsec)
dev->is_thunderbolt = 1;
}
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 || parent->external_facing))
dev->untrusted = true;
}
static void pci_set_removable(struct pci_dev *dev)
{
struct pci_dev *parent = pci_upstream_bridge(dev);
/*
* We (only) consider everything downstream from an external_facing
* device to be removable by the user. We're mainly concerned with
* consumer platforms with user accessible thunderbolt ports that are
* vulnerable to DMA attacks, and we expect those ports to be marked by
* the firmware as external_facing. Devices in traditional hotplug
* slots can technically be removed, but the expectation is that unless
* the port is marked with external_facing, such devices are less
* accessible to user / may not be removed by end user, and thus not
* exposed as "removable" to userspace.
*/
if (parent &&
(parent->external_facing || dev_is_removable(&parent->dev)))
dev_set_removable(&dev->dev, DEVICE_REMOVABLE);
}
/**
* 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_ext - 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 (PCI_POSSIBLE_ERROR(status) || 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)
/**
* 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_set_of_node(dev);
pci_set_acpi_fwnode(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 */
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);
pci_set_removable(dev);
pci_info(dev, "[%04x:%04x] type %02x class %#08x\n",
dev->vendor, dev->device, dev->hdr_type, dev->class);
/* Device class may be changed after fixup */
class = dev->class >> 8;
if (dev->non_compliant_bars && !dev->mmio_always_on) {
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);
pci_release_of_node(dev);
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))
return;
/* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */
if (dev->is_virtfn)
return;
/*
* For Root Complex Integrated Endpoints, program the maximum
* supported value unless limited by the PCIE_BUS_PEER2PEER case.
*/
if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
if (pcie_bus_config == PCIE_BUS_PEER2PEER)
mps = 128;
else
mps = 128 << dev->pcie_mpss;
rc = pcie_set_mps(dev, 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",
mps);
}
return;
}
if (!bridge || !pci_is_pcie(bridge))
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 = pcie_find_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;
/* Read L1 PM substate capabilities */
dev->l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
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) {
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_LTR_EN);
dev->ltr_path = 1;
return;
}
/*
* If we're configuring a hot-added device, LTR was likely
* disabled in the upstream bridge, so re-enable it before enabling
* it in the new device.
*/
bridge = pci_upstream_bridge(dev);
if (bridge && bridge->ltr_path) {
pci_bridge_reconfigure_ltr(dev);
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_rcec_exit(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);
dev_dbg(dev, "device released\n");
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);
#ifdef CONFIG_PCI_MSI
raw_spin_lock_init(&dev->msi_lock);
#endif
return dev;
}
EXPORT_SYMBOL(pci_alloc_dev);
static bool pci_bus_crs_vendor_id(u32 l)
{
return (l & 0xffff) == PCI_VENDOR_ID_PCI_SIG;
}
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 (PCI_ERROR_RESPONSE) if a slot is empty: */
if (PCI_POSSIBLE_ERROR(*l) || *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;
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 */
pci_msi_init(dev); /* Disable MSI */
pci_msix_init(dev); /* Disable MSI-X */
/* 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_acs_init(dev); /* Access Control Services */
pci_ptm_init(dev); /* Precision Time Measurement */
pci_aer_init(dev); /* Advanced Error Reporting */
pci_dpc_init(dev); /* Downstream Port Containment */
pci_rcec_init(dev); /* Root Complex Event Collector */
pcie_report_downtraining(dev);
pci_init_reset_methods(dev);
}
/*
* 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_device_add()
* 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_device_add(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 int next_ari_fn(struct pci_bus *bus, struct pci_dev *dev, int fn)
{
int pos;
u16 cap = 0;
unsigned int next_fn;
if (!dev)
return -ENODEV;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
if (!pos)
return -ENODEV;
pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap);
next_fn = PCI_ARI_CAP_NFN(cap);
if (next_fn <= fn)
return -ENODEV; /* protect against malformed list */
return next_fn;
}
static int next_fn(struct pci_bus *bus, struct pci_dev *dev, int fn)
{
if (pci_ari_enabled(bus))
return next_ari_fn(bus, dev, fn);
if (fn >= 7)
return -ENODEV;
/* only multifunction devices may have more functions */
if (dev && !dev->multifunction)
return -ENODEV;
return fn + 1;
}
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)
{
struct pci_dev *dev;
int fn = 0, nr = 0;
if (only_one_child(bus) && (devfn > 0))
return 0; /* Already scanned the entire slot */
do {
dev = pci_scan_single_device(bus, devfn + fn);
if (dev) {
if (!pci_dev_is_added(dev))
nr++;
if (fn > 0)
dev->multifunction = 1;
} else if (fn == 0) {
/*
* Function 0 is required unless we are running on
* a hypervisor that passes through individual PCI
* functions.
*/
if (!hypervisor_isolated_pci_functions())
break;
}
fn = next_fn(bus, dev, fn);
} while (fn >= 0);
/* 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, cmax, max = start;
struct pci_dev *dev;
dev_dbg(&bus->dev, "scanning bus\n");
/* Go find them, Rover! */
for (devfn = 0; devfn < 256; devfn += 8)
pci_scan_slot(bus, devfn);
/* 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 (max - cmax > 1)
used_buses += max - cmax - 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 if 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:
put_device(&bridge->dev);
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) {
bridge->busnr = window->res->start;
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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