/*
* 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/acpi.h>
#include <linux/bitmap.h>
#include <asm/e820.h>
#include "pci.h"
/* aperture is up to 256MB but BIOS may reserve less */
#define MMCONFIG_APER_MIN (2 * 1024*1024)
#define MMCONFIG_APER_MAX (256 * 1024*1024)
DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS);
/* Indicate if the mmcfg resources have been placed into the resource table. */
static int __initdata pci_mmcfg_resources_inserted;
/* K8 systems have some devices (typically in the builtin northbridge)
that are only accessible using type1
Normally this can be expressed in the MCFG by not listing them
and assigning suitable _SEGs, but this isn't implemented in some BIOS.
Instead try to discover all devices on bus 0 that are unreachable using MM
and fallback for them. */
static void __init unreachable_devices(void)
{
int i, bus;
/* Use the max bus number from ACPI here? */
for (bus = 0; bus < PCI_MMCFG_MAX_CHECK_BUS; bus++) {
for (i = 0; i < 32; i++) {
unsigned int devfn = PCI_DEVFN(i, 0);
u32 val1, val2;
pci_conf1_read(0, bus, devfn, 0, 4, &val1);
if (val1 == 0xffffffff)
continue;
if (pci_mmcfg_arch_reachable(0, bus, devfn)) {
raw_pci_ops->read(0, bus, devfn, 0, 4, &val2);
if (val1 == val2)
continue;
}
set_bit(i + 32 * bus, pci_mmcfg_fallback_slots);
printk(KERN_NOTICE "PCI: No mmconfig possible on device"
" %02x:%02x\n", bus, i);
}
}
}
static const char __init *pci_mmcfg_e7520(void)
{
u32 win;
pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0xce, 2, &win);
win = win & 0xf000;
if(win == 0x0000 || win == 0xf000)
pci_mmcfg_config_num = 0;
else {
pci_mmcfg_config_num = 1;
pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
if (!pci_mmcfg_config)
return NULL;
pci_mmcfg_config[0].address = win << 16;
pci_mmcfg_config[0].pci_segment = 0;
pci_mmcfg_config[0].start_bus_number = 0;
pci_mmcfg_config[0].end_bus_number = 255;
}
return "Intel Corporation E7520 Memory Controller Hub";
}
static const char __init *pci_mmcfg_intel_945(void)
{
u32 pciexbar, mask = 0, len = 0;
pci_mmcfg_config_num = 1;
pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0x48, 4, &pciexbar);
/* Enable bit */
if (!(pciexbar & 1))
pci_mmcfg_config_num = 0;
/* 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:
pci_mmcfg_config_num = 0;
}
/* Errata #2, things break when not aligned on a 256Mb boundary */
/* Can only happen in 64M/128M mode */
if ((pciexbar & mask) & 0x0fffffffU)
pci_mmcfg_config_num = 0;
/* Don't hit the APIC registers and their friends */
if ((pciexbar & mask) >= 0xf0000000U)
pci_mmcfg_config_num = 0;
if (pci_mmcfg_config_num) {
pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
if (!pci_mmcfg_config)
return NULL;
pci_mmcfg_config[0].address = pciexbar & mask;
pci_mmcfg_config[0].pci_segment = 0;
pci_mmcfg_config[0].start_bus_number = 0;
pci_mmcfg_config[0].end_bus_number = (len >> 20) - 1;
}
return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
}
struct pci_mmcfg_hostbridge_probe {
u32 vendor;
u32 device;
const char *(*probe)(void);
};
static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
};
static int __init pci_mmcfg_check_hostbridge(void)
{
u32 l;
u16 vendor, device;
int i;
const char *name;
pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0, 4, &l);
vendor = l & 0xffff;
device = (l >> 16) & 0xffff;
pci_mmcfg_config_num = 0;
pci_mmcfg_config = NULL;
name = NULL;
for (i = 0; !name && i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
if (pci_mmcfg_probes[i].vendor == vendor &&
pci_mmcfg_probes[i].device == device)
name = pci_mmcfg_probes[i].probe();
}
if (name) {
printk(KERN_INFO "PCI: Found %s %s MMCONFIG support.\n",
name, pci_mmcfg_config_num ? "with" : "without");
}
return name != NULL;
}
static void __init pci_mmcfg_insert_resources(unsigned long resource_flags)
{
#define PCI_MMCFG_RESOURCE_NAME_LEN 19
int i;
struct resource *res;
char *names;
unsigned num_buses;
res = kcalloc(PCI_MMCFG_RESOURCE_NAME_LEN + sizeof(*res),
pci_mmcfg_config_num, GFP_KERNEL);
if (!res) {
printk(KERN_ERR "PCI: Unable to allocate MMCONFIG resources\n");
return;
}
names = (void *)&res[pci_mmcfg_config_num];
for (i = 0; i < pci_mmcfg_config_num; i++, res++) {
struct acpi_mcfg_allocation *cfg = &pci_mmcfg_config[i];
num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
res->name = names;
snprintf(names, PCI_MMCFG_RESOURCE_NAME_LEN, "PCI MMCONFIG %u",
cfg->pci_segment);
res->start = cfg->address;
res->end = res->start + (num_buses << 20) - 1;
res->flags = IORESOURCE_MEM | resource_flags;
insert_resource(&iomem_resource, res);
names += PCI_MMCFG_RESOURCE_NAME_LEN;
}
/* Mark that the resources have been inserted. */
pci_mmcfg_resources_inserted = 1;
}
static void __init pci_mmcfg_reject_broken(int type)
{
typeof(pci_mmcfg_config[0]) *cfg;
if ((pci_mmcfg_config_num == 0) ||
(pci_mmcfg_config == NULL) ||
(pci_mmcfg_config[0].address == 0))
return;
cfg = &pci_mmcfg_config[0];
/*
* Handle more broken MCFG tables on Asus etc.
* They only contain a single entry for bus 0-0.
*/
if (pci_mmcfg_config_num == 1 &&
cfg->pci_segment == 0 &&
(cfg->start_bus_number | cfg->end_bus_number) == 0) {
printk(KERN_ERR "PCI: start and end of bus number is 0. "
"Rejected as broken MCFG.\n");
goto reject;
}
/*
* Only do this check when type 1 works. If it doesn't work
* assume we run on a Mac and always use MCFG
*/
if (type == 1 && !e820_all_mapped(cfg->address,
cfg->address + MMCONFIG_APER_MIN,
E820_RESERVED)) {
printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not"
" E820-reserved\n", cfg->address);
goto reject;
}
return;
reject:
printk(KERN_ERR "PCI: Not using MMCONFIG.\n");
kfree(pci_mmcfg_config);
pci_mmcfg_config = NULL;
pci_mmcfg_config_num = 0;
}
void __init pci_mmcfg_init(int type)
{
int known_bridge = 0;
if ((pci_probe & PCI_PROBE_MMCONF) == 0)
return;
if (type == 1 && pci_mmcfg_check_hostbridge())
known_bridge = 1;
if (!known_bridge) {
acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
pci_mmcfg_reject_broken(type);
}
if ((pci_mmcfg_config_num == 0) ||
(pci_mmcfg_config == NULL) ||
(pci_mmcfg_config[0].address == 0))
return;
if (pci_mmcfg_arch_init()) {
if (type == 1)
unreachable_devices();
if (known_bridge)
pci_mmcfg_insert_resources(IORESOURCE_BUSY);
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
} else {
/*
* Signal not to attempt to insert mmcfg resources because
* the architecture mmcfg setup could not initialize.
*/
pci_mmcfg_resources_inserted = 1;
}
}
static int __init pci_mmcfg_late_insert_resources(void)
{
/*
* If resources are already inserted or we are not using MMCONFIG,
* don't insert the resources.
*/
if ((pci_mmcfg_resources_inserted == 1) ||
(pci_probe & PCI_PROBE_MMCONF) == 0 ||
(pci_mmcfg_config_num == 0) ||
(pci_mmcfg_config == NULL) ||
(pci_mmcfg_config[0].address == 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.
*/
pci_mmcfg_insert_resources(0);
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);
