alistair23-linux/arch/x86/pci/mmconfig-shared.c
Chen, Gong d91525eb8e ACPI, EINJ: Enhance error injection tolerance level
Some BIOSes utilize PCI MMCFG space read/write opertion to trigger
specific errors. EINJ will report errors as below when hitting such
cases:

APEI: Can not request [mem 0x83f990a0-0x83f990a3] for APEI EINJ Trigger registers

It is because on x86 platform ACPI based PCI MMCFG logic has
reserved all MMCFG spaces so that EINJ can't reserve it again.
We already trust the ACPI/APEI code when using the EINJ interface
so it is not a big leap to also trust it to access the right
MMCFG addresses. Skip address checking to allow the access.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2014-12-15 11:36:37 -08:00

819 lines
19 KiB
C

/*
* mmconfig-shared.c - Low-level direct PCI config space access via
* MMCONFIG - common code between i386 and x86-64.
*
* This code does:
* - known chipset handling
* - ACPI decoding and validation
*
* Per-architecture code takes care of the mappings and accesses
* themselves.
*/
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/sfi_acpi.h>
#include <linux/bitmap.h>
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <asm/e820.h>
#include <asm/pci_x86.h>
#include <asm/acpi.h>
#define PREFIX "PCI: "
/* Indicate if the mmcfg resources have been placed into the resource table. */
static bool pci_mmcfg_running_state;
static bool pci_mmcfg_arch_init_failed;
static DEFINE_MUTEX(pci_mmcfg_lock);
LIST_HEAD(pci_mmcfg_list);
static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
{
if (cfg->res.parent)
release_resource(&cfg->res);
list_del(&cfg->list);
kfree(cfg);
}
static void __init free_all_mmcfg(void)
{
struct pci_mmcfg_region *cfg, *tmp;
pci_mmcfg_arch_free();
list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
pci_mmconfig_remove(cfg);
}
static void list_add_sorted(struct pci_mmcfg_region *new)
{
struct pci_mmcfg_region *cfg;
/* keep list sorted by segment and starting bus number */
list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
if (cfg->segment > new->segment ||
(cfg->segment == new->segment &&
cfg->start_bus >= new->start_bus)) {
list_add_tail_rcu(&new->list, &cfg->list);
return;
}
}
list_add_tail_rcu(&new->list, &pci_mmcfg_list);
}
static struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
int end, u64 addr)
{
struct pci_mmcfg_region *new;
struct resource *res;
if (addr == 0)
return NULL;
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return NULL;
new->address = addr;
new->segment = segment;
new->start_bus = start;
new->end_bus = end;
res = &new->res;
res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
"PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
res->name = new->name;
return new;
}
static struct pci_mmcfg_region *__init pci_mmconfig_add(int segment, int start,
int end, u64 addr)
{
struct pci_mmcfg_region *new;
new = pci_mmconfig_alloc(segment, start, end, addr);
if (new) {
mutex_lock(&pci_mmcfg_lock);
list_add_sorted(new);
mutex_unlock(&pci_mmcfg_lock);
pr_info(PREFIX
"MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
"(base %#lx)\n",
segment, start, end, &new->res, (unsigned long)addr);
}
return new;
}
struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
{
struct pci_mmcfg_region *cfg;
list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
if (cfg->segment == segment &&
cfg->start_bus <= bus && bus <= cfg->end_bus)
return cfg;
return NULL;
}
static const char *__init pci_mmcfg_e7520(void)
{
u32 win;
raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
win = win & 0xf000;
if (win == 0x0000 || win == 0xf000)
return NULL;
if (pci_mmconfig_add(0, 0, 255, win << 16) == NULL)
return NULL;
return "Intel Corporation E7520 Memory Controller Hub";
}
static const char *__init pci_mmcfg_intel_945(void)
{
u32 pciexbar, mask = 0, len = 0;
raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
/* Enable bit */
if (!(pciexbar & 1))
return NULL;
/* Size bits */
switch ((pciexbar >> 1) & 3) {
case 0:
mask = 0xf0000000U;
len = 0x10000000U;
break;
case 1:
mask = 0xf8000000U;
len = 0x08000000U;
break;
case 2:
mask = 0xfc000000U;
len = 0x04000000U;
break;
default:
return NULL;
}
/* Errata #2, things break when not aligned on a 256Mb boundary */
/* Can only happen in 64M/128M mode */
if ((pciexbar & mask) & 0x0fffffffU)
return NULL;
/* Don't hit the APIC registers and their friends */
if ((pciexbar & mask) >= 0xf0000000U)
return NULL;
if (pci_mmconfig_add(0, 0, (len >> 20) - 1, pciexbar & mask) == NULL)
return NULL;
return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
}
static const char *__init pci_mmcfg_amd_fam10h(void)
{
u32 low, high, address;
u64 base, msr;
int i;
unsigned segnbits = 0, busnbits, end_bus;
if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
return NULL;
address = MSR_FAM10H_MMIO_CONF_BASE;
if (rdmsr_safe(address, &low, &high))
return NULL;
msr = high;
msr <<= 32;
msr |= low;
/* mmconfig is not enable */
if (!(msr & FAM10H_MMIO_CONF_ENABLE))
return NULL;
base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
FAM10H_MMIO_CONF_BUSRANGE_MASK;
/*
* only handle bus 0 ?
* need to skip it
*/
if (!busnbits)
return NULL;
if (busnbits > 8) {
segnbits = busnbits - 8;
busnbits = 8;
}
end_bus = (1 << busnbits) - 1;
for (i = 0; i < (1 << segnbits); i++)
if (pci_mmconfig_add(i, 0, end_bus,
base + (1<<28) * i) == NULL) {
free_all_mmcfg();
return NULL;
}
return "AMD Family 10h NB";
}
static bool __initdata mcp55_checked;
static const char *__init pci_mmcfg_nvidia_mcp55(void)
{
int bus;
int mcp55_mmconf_found = 0;
static const u32 extcfg_regnum __initconst = 0x90;
static const u32 extcfg_regsize __initconst = 4;
static const u32 extcfg_enable_mask __initconst = 1 << 31;
static const u32 extcfg_start_mask __initconst = 0xff << 16;
static const int extcfg_start_shift __initconst = 16;
static const u32 extcfg_size_mask __initconst = 0x3 << 28;
static const int extcfg_size_shift __initconst = 28;
static const int extcfg_sizebus[] __initconst = {
0x100, 0x80, 0x40, 0x20
};
static const u32 extcfg_base_mask[] __initconst = {
0x7ff8, 0x7ffc, 0x7ffe, 0x7fff
};
static const int extcfg_base_lshift __initconst = 25;
/*
* do check if amd fam10h already took over
*/
if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
return NULL;
mcp55_checked = true;
for (bus = 0; bus < 256; bus++) {
u64 base;
u32 l, extcfg;
u16 vendor, device;
int start, size_index, end;
raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
vendor = l & 0xffff;
device = (l >> 16) & 0xffff;
if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
continue;
raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
extcfg_regsize, &extcfg);
if (!(extcfg & extcfg_enable_mask))
continue;
size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
base = extcfg & extcfg_base_mask[size_index];
/* base could > 4G */
base <<= extcfg_base_lshift;
start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
end = start + extcfg_sizebus[size_index] - 1;
if (pci_mmconfig_add(0, start, end, base) == NULL)
continue;
mcp55_mmconf_found++;
}
if (!mcp55_mmconf_found)
return NULL;
return "nVidia MCP55";
}
struct pci_mmcfg_hostbridge_probe {
u32 bus;
u32 devfn;
u32 vendor;
u32 device;
const char *(*probe)(void);
};
static const struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initconst = {
{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
0x1200, pci_mmcfg_amd_fam10h },
{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
0x1200, pci_mmcfg_amd_fam10h },
{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
0x0369, pci_mmcfg_nvidia_mcp55 },
};
static void __init pci_mmcfg_check_end_bus_number(void)
{
struct pci_mmcfg_region *cfg, *cfgx;
/* Fixup overlaps */
list_for_each_entry(cfg, &pci_mmcfg_list, list) {
if (cfg->end_bus < cfg->start_bus)
cfg->end_bus = 255;
/* Don't access the list head ! */
if (cfg->list.next == &pci_mmcfg_list)
break;
cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
if (cfg->end_bus >= cfgx->start_bus)
cfg->end_bus = cfgx->start_bus - 1;
}
}
static int __init pci_mmcfg_check_hostbridge(void)
{
u32 l;
u32 bus, devfn;
u16 vendor, device;
int i;
const char *name;
if (!raw_pci_ops)
return 0;
free_all_mmcfg();
for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
bus = pci_mmcfg_probes[i].bus;
devfn = pci_mmcfg_probes[i].devfn;
raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
vendor = l & 0xffff;
device = (l >> 16) & 0xffff;
name = NULL;
if (pci_mmcfg_probes[i].vendor == vendor &&
pci_mmcfg_probes[i].device == device)
name = pci_mmcfg_probes[i].probe();
if (name)
pr_info(PREFIX "%s with MMCONFIG support\n", name);
}
/* some end_bus_number is crazy, fix it */
pci_mmcfg_check_end_bus_number();
return !list_empty(&pci_mmcfg_list);
}
static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
{
struct resource *mcfg_res = data;
struct acpi_resource_address64 address;
acpi_status status;
if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
struct acpi_resource_fixed_memory32 *fixmem32 =
&res->data.fixed_memory32;
if (!fixmem32)
return AE_OK;
if ((mcfg_res->start >= fixmem32->address) &&
(mcfg_res->end < (fixmem32->address +
fixmem32->address_length))) {
mcfg_res->flags = 1;
return AE_CTRL_TERMINATE;
}
}
if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
(res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
return AE_OK;
status = acpi_resource_to_address64(res, &address);
if (ACPI_FAILURE(status) ||
(address.address_length <= 0) ||
(address.resource_type != ACPI_MEMORY_RANGE))
return AE_OK;
if ((mcfg_res->start >= address.minimum) &&
(mcfg_res->end < (address.minimum + address.address_length))) {
mcfg_res->flags = 1;
return AE_CTRL_TERMINATE;
}
return AE_OK;
}
static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
void *context, void **rv)
{
struct resource *mcfg_res = context;
acpi_walk_resources(handle, METHOD_NAME__CRS,
check_mcfg_resource, context);
if (mcfg_res->flags)
return AE_CTRL_TERMINATE;
return AE_OK;
}
static int is_acpi_reserved(u64 start, u64 end, unsigned not_used)
{
struct resource mcfg_res;
mcfg_res.start = start;
mcfg_res.end = end - 1;
mcfg_res.flags = 0;
acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
if (!mcfg_res.flags)
acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
NULL);
return mcfg_res.flags;
}
typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
static int __ref is_mmconf_reserved(check_reserved_t is_reserved,
struct pci_mmcfg_region *cfg,
struct device *dev, int with_e820)
{
u64 addr = cfg->res.start;
u64 size = resource_size(&cfg->res);
u64 old_size = size;
int num_buses;
char *method = with_e820 ? "E820" : "ACPI motherboard resources";
while (!is_reserved(addr, addr + size, E820_RESERVED)) {
size >>= 1;
if (size < (16UL<<20))
break;
}
if (size < (16UL<<20) && size != old_size)
return 0;
if (dev)
dev_info(dev, "MMCONFIG at %pR reserved in %s\n",
&cfg->res, method);
else
pr_info(PREFIX "MMCONFIG at %pR reserved in %s\n",
&cfg->res, method);
if (old_size != size) {
/* update end_bus */
cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
num_buses = cfg->end_bus - cfg->start_bus + 1;
cfg->res.end = cfg->res.start +
PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
"PCI MMCONFIG %04x [bus %02x-%02x]",
cfg->segment, cfg->start_bus, cfg->end_bus);
if (dev)
dev_info(dev,
"MMCONFIG "
"at %pR (base %#lx) (size reduced!)\n",
&cfg->res, (unsigned long) cfg->address);
else
pr_info(PREFIX
"MMCONFIG for %04x [bus%02x-%02x] "
"at %pR (base %#lx) (size reduced!)\n",
cfg->segment, cfg->start_bus, cfg->end_bus,
&cfg->res, (unsigned long) cfg->address);
}
return 1;
}
static int __ref pci_mmcfg_check_reserved(struct device *dev,
struct pci_mmcfg_region *cfg, int early)
{
if (!early && !acpi_disabled) {
if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, 0))
return 1;
if (dev)
dev_info(dev, FW_INFO
"MMCONFIG at %pR not reserved in "
"ACPI motherboard resources\n",
&cfg->res);
else
pr_info(FW_INFO PREFIX
"MMCONFIG at %pR not reserved in "
"ACPI motherboard resources\n",
&cfg->res);
}
/*
* e820_all_mapped() is marked as __init.
* All entries from ACPI MCFG table have been checked at boot time.
* For MCFG information constructed from hotpluggable host bridge's
* _CBA method, just assume it's reserved.
*/
if (pci_mmcfg_running_state)
return 1;
/* Don't try to do this check unless configuration
type 1 is available. how about type 2 ?*/
if (raw_pci_ops)
return is_mmconf_reserved(e820_all_mapped, cfg, dev, 1);
return 0;
}
static void __init pci_mmcfg_reject_broken(int early)
{
struct pci_mmcfg_region *cfg;
list_for_each_entry(cfg, &pci_mmcfg_list, list) {
if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
pr_info(PREFIX "not using MMCONFIG\n");
free_all_mmcfg();
return;
}
}
}
static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
struct acpi_mcfg_allocation *cfg)
{
int year;
if (cfg->address < 0xFFFFFFFF)
return 0;
if (!strncmp(mcfg->header.oem_id, "SGI", 3))
return 0;
if (mcfg->header.revision >= 1) {
if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
year >= 2010)
return 0;
}
pr_err(PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
"is above 4GB, ignored\n", cfg->pci_segment,
cfg->start_bus_number, cfg->end_bus_number, cfg->address);
return -EINVAL;
}
static int __init pci_parse_mcfg(struct acpi_table_header *header)
{
struct acpi_table_mcfg *mcfg;
struct acpi_mcfg_allocation *cfg_table, *cfg;
unsigned long i;
int entries;
if (!header)
return -EINVAL;
mcfg = (struct acpi_table_mcfg *)header;
/* how many config structures do we have */
free_all_mmcfg();
entries = 0;
i = header->length - sizeof(struct acpi_table_mcfg);
while (i >= sizeof(struct acpi_mcfg_allocation)) {
entries++;
i -= sizeof(struct acpi_mcfg_allocation);
}
if (entries == 0) {
pr_err(PREFIX "MMCONFIG has no entries\n");
return -ENODEV;
}
cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
for (i = 0; i < entries; i++) {
cfg = &cfg_table[i];
if (acpi_mcfg_check_entry(mcfg, cfg)) {
free_all_mmcfg();
return -ENODEV;
}
if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
cfg->end_bus_number, cfg->address) == NULL) {
pr_warn(PREFIX "no memory for MCFG entries\n");
free_all_mmcfg();
return -ENOMEM;
}
}
return 0;
}
#ifdef CONFIG_ACPI_APEI
extern int (*arch_apei_filter_addr)(int (*func)(__u64 start, __u64 size,
void *data), void *data);
static int pci_mmcfg_for_each_region(int (*func)(__u64 start, __u64 size,
void *data), void *data)
{
struct pci_mmcfg_region *cfg;
int rc;
if (list_empty(&pci_mmcfg_list))
return 0;
list_for_each_entry(cfg, &pci_mmcfg_list, list) {
rc = func(cfg->res.start, resource_size(&cfg->res), data);
if (rc)
return rc;
}
return 0;
}
#define set_apei_filter() (arch_apei_filter_addr = pci_mmcfg_for_each_region)
#else
#define set_apei_filter()
#endif
static void __init __pci_mmcfg_init(int early)
{
pci_mmcfg_reject_broken(early);
if (list_empty(&pci_mmcfg_list))
return;
if (pcibios_last_bus < 0) {
const struct pci_mmcfg_region *cfg;
list_for_each_entry(cfg, &pci_mmcfg_list, list) {
if (cfg->segment)
break;
pcibios_last_bus = cfg->end_bus;
}
}
if (pci_mmcfg_arch_init())
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
else {
free_all_mmcfg();
pci_mmcfg_arch_init_failed = true;
}
}
static int __initdata known_bridge;
void __init pci_mmcfg_early_init(void)
{
if (pci_probe & PCI_PROBE_MMCONF) {
if (pci_mmcfg_check_hostbridge())
known_bridge = 1;
else
acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
__pci_mmcfg_init(1);
set_apei_filter();
}
}
void __init pci_mmcfg_late_init(void)
{
/* MMCONFIG disabled */
if ((pci_probe & PCI_PROBE_MMCONF) == 0)
return;
if (known_bridge)
return;
/* MMCONFIG hasn't been enabled yet, try again */
if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
__pci_mmcfg_init(0);
}
}
static int __init pci_mmcfg_late_insert_resources(void)
{
struct pci_mmcfg_region *cfg;
pci_mmcfg_running_state = true;
/* If we are not using MMCONFIG, don't insert the resources. */
if ((pci_probe & PCI_PROBE_MMCONF) == 0)
return 1;
/*
* Attempt to insert the mmcfg resources but not with the busy flag
* marked so it won't cause request errors when __request_region is
* called.
*/
list_for_each_entry(cfg, &pci_mmcfg_list, list)
if (!cfg->res.parent)
insert_resource(&iomem_resource, &cfg->res);
return 0;
}
/*
* Perform MMCONFIG resource insertion after PCI initialization to allow for
* misprogrammed MCFG tables that state larger sizes but actually conflict
* with other system resources.
*/
late_initcall(pci_mmcfg_late_insert_resources);
/* Add MMCFG information for host bridges */
int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
phys_addr_t addr)
{
int rc;
struct resource *tmp = NULL;
struct pci_mmcfg_region *cfg;
if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
return -ENODEV;
if (start > end)
return -EINVAL;
mutex_lock(&pci_mmcfg_lock);
cfg = pci_mmconfig_lookup(seg, start);
if (cfg) {
if (cfg->end_bus < end)
dev_info(dev, FW_INFO
"MMCONFIG for "
"domain %04x [bus %02x-%02x] "
"only partially covers this bridge\n",
cfg->segment, cfg->start_bus, cfg->end_bus);
mutex_unlock(&pci_mmcfg_lock);
return -EEXIST;
}
if (!addr) {
mutex_unlock(&pci_mmcfg_lock);
return -EINVAL;
}
rc = -EBUSY;
cfg = pci_mmconfig_alloc(seg, start, end, addr);
if (cfg == NULL) {
dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
rc = -ENOMEM;
} else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
&cfg->res);
} else {
/* Insert resource if it's not in boot stage */
if (pci_mmcfg_running_state)
tmp = insert_resource_conflict(&iomem_resource,
&cfg->res);
if (tmp) {
dev_warn(dev,
"MMCONFIG %pR conflicts with "
"%s %pR\n",
&cfg->res, tmp->name, tmp);
} else if (pci_mmcfg_arch_map(cfg)) {
dev_warn(dev, "fail to map MMCONFIG %pR.\n",
&cfg->res);
} else {
list_add_sorted(cfg);
dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
&cfg->res, (unsigned long)addr);
cfg = NULL;
rc = 0;
}
}
if (cfg) {
if (cfg->res.parent)
release_resource(&cfg->res);
kfree(cfg);
}
mutex_unlock(&pci_mmcfg_lock);
return rc;
}
/* Delete MMCFG information for host bridges */
int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
{
struct pci_mmcfg_region *cfg;
mutex_lock(&pci_mmcfg_lock);
list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
if (cfg->segment == seg && cfg->start_bus == start &&
cfg->end_bus == end) {
list_del_rcu(&cfg->list);
synchronize_rcu();
pci_mmcfg_arch_unmap(cfg);
if (cfg->res.parent)
release_resource(&cfg->res);
mutex_unlock(&pci_mmcfg_lock);
kfree(cfg);
return 0;
}
mutex_unlock(&pci_mmcfg_lock);
return -ENOENT;
}