android_kernel_xiaomi_sm8350/arch/i386/pci/common.c
Andi Kleen 0637a70a5d [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
Some buggy systems can machine check when config space accesses
happen for some non existent devices.  i386/x86-64 do some early
device scans that might trigger this. Allow pci=noearly to disable
this. Also when type 1 is disabling also don't do any early
accesses which are always type1.

This moves the pci= configuration parsing to be a early parameter.
I don't think this can break anything because it only changes
a single global that is only used by PCI.

Cc: gregkh@suse.de
Cc: Trammell Hudson <hudson@osresearch.net>

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00

295 lines
6.8 KiB
C

/*
* Low-Level PCI Support for PC
*
* (c) 1999--2000 Martin Mares <mj@ucw.cz>
*/
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <asm/acpi.h>
#include <asm/segment.h>
#include <asm/io.h>
#include <asm/smp.h>
#include "pci.h"
unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
PCI_PROBE_MMCONF;
int pci_routeirq;
int pcibios_last_bus = -1;
unsigned long pirq_table_addr;
struct pci_bus *pci_root_bus;
struct pci_raw_ops *raw_pci_ops;
static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
{
return raw_pci_ops->read(0, bus->number, devfn, where, size, value);
}
static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
{
return raw_pci_ops->write(0, bus->number, devfn, where, size, value);
}
struct pci_ops pci_root_ops = {
.read = pci_read,
.write = pci_write,
};
/*
* legacy, numa, and acpi all want to call pcibios_scan_root
* from their initcalls. This flag prevents that.
*/
int pcibios_scanned;
/*
* This interrupt-safe spinlock protects all accesses to PCI
* configuration space.
*/
DEFINE_SPINLOCK(pci_config_lock);
/*
* Several buggy motherboards address only 16 devices and mirror
* them to next 16 IDs. We try to detect this `feature' on all
* primary buses (those containing host bridges as they are
* expected to be unique) and remove the ghost devices.
*/
static void __devinit pcibios_fixup_ghosts(struct pci_bus *b)
{
struct list_head *ln, *mn;
struct pci_dev *d, *e;
int mirror = PCI_DEVFN(16,0);
int seen_host_bridge = 0;
int i;
DBG("PCI: Scanning for ghost devices on bus %d\n", b->number);
list_for_each(ln, &b->devices) {
d = pci_dev_b(ln);
if ((d->class >> 8) == PCI_CLASS_BRIDGE_HOST)
seen_host_bridge++;
for (mn=ln->next; mn != &b->devices; mn=mn->next) {
e = pci_dev_b(mn);
if (e->devfn != d->devfn + mirror ||
e->vendor != d->vendor ||
e->device != d->device ||
e->class != d->class)
continue;
for(i=0; i<PCI_NUM_RESOURCES; i++)
if (e->resource[i].start != d->resource[i].start ||
e->resource[i].end != d->resource[i].end ||
e->resource[i].flags != d->resource[i].flags)
continue;
break;
}
if (mn == &b->devices)
return;
}
if (!seen_host_bridge)
return;
printk(KERN_WARNING "PCI: Ignoring ghost devices on bus %02x\n", b->number);
ln = &b->devices;
while (ln->next != &b->devices) {
d = pci_dev_b(ln->next);
if (d->devfn >= mirror) {
list_del(&d->global_list);
list_del(&d->bus_list);
kfree(d);
} else
ln = ln->next;
}
}
/*
* Called after each bus is probed, but before its children
* are examined.
*/
void __devinit pcibios_fixup_bus(struct pci_bus *b)
{
pcibios_fixup_ghosts(b);
pci_read_bridge_bases(b);
}
/*
* Enable renumbering of PCI bus# ranges to reach all PCI busses (Cardbus)
*/
#ifdef __i386__
static int __devinit assign_all_busses(struct dmi_system_id *d)
{
pci_probe |= PCI_ASSIGN_ALL_BUSSES;
printk(KERN_INFO "%s detected: enabling PCI bus# renumbering"
" (pci=assign-busses)\n", d->ident);
return 0;
}
#endif
/*
* Laptops which need pci=assign-busses to see Cardbus cards
*/
static struct dmi_system_id __devinitdata pciprobe_dmi_table[] = {
#ifdef __i386__
{
.callback = assign_all_busses,
.ident = "Samsung X20 Laptop",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Samsung Electronics"),
DMI_MATCH(DMI_PRODUCT_NAME, "SX20S"),
},
},
#endif /* __i386__ */
{}
};
struct pci_bus * __devinit pcibios_scan_root(int busnum)
{
struct pci_bus *bus = NULL;
dmi_check_system(pciprobe_dmi_table);
while ((bus = pci_find_next_bus(bus)) != NULL) {
if (bus->number == busnum) {
/* Already scanned */
return bus;
}
}
printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
return pci_scan_bus_parented(NULL, busnum, &pci_root_ops, NULL);
}
extern u8 pci_cache_line_size;
static int __init pcibios_init(void)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
if (!raw_pci_ops) {
printk(KERN_WARNING "PCI: System does not support PCI\n");
return 0;
}
/*
* Assume PCI cacheline size of 32 bytes for all x86s except K7/K8
* and P4. It's also good for 386/486s (which actually have 16)
* as quite a few PCI devices do not support smaller values.
*/
pci_cache_line_size = 32 >> 2;
if (c->x86 >= 6 && c->x86_vendor == X86_VENDOR_AMD)
pci_cache_line_size = 64 >> 2; /* K7 & K8 */
else if (c->x86 > 6 && c->x86_vendor == X86_VENDOR_INTEL)
pci_cache_line_size = 128 >> 2; /* P4 */
pcibios_resource_survey();
#ifdef CONFIG_PCI_BIOS
if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
pcibios_sort();
#endif
return 0;
}
subsys_initcall(pcibios_init);
char * __devinit pcibios_setup(char *str)
{
if (!strcmp(str, "off")) {
pci_probe = 0;
return NULL;
}
#ifdef CONFIG_PCI_BIOS
else if (!strcmp(str, "bios")) {
pci_probe = PCI_PROBE_BIOS;
return NULL;
} else if (!strcmp(str, "nobios")) {
pci_probe &= ~PCI_PROBE_BIOS;
return NULL;
} else if (!strcmp(str, "nosort")) {
pci_probe |= PCI_NO_SORT;
return NULL;
} else if (!strcmp(str, "biosirq")) {
pci_probe |= PCI_BIOS_IRQ_SCAN;
return NULL;
} else if (!strncmp(str, "pirqaddr=", 9)) {
pirq_table_addr = simple_strtoul(str+9, NULL, 0);
return NULL;
}
#endif
#ifdef CONFIG_PCI_DIRECT
else if (!strcmp(str, "conf1")) {
pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
return NULL;
}
else if (!strcmp(str, "conf2")) {
pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
return NULL;
}
#endif
#ifdef CONFIG_PCI_MMCONFIG
else if (!strcmp(str, "nommconf")) {
pci_probe &= ~PCI_PROBE_MMCONF;
return NULL;
}
#endif
else if (!strcmp(str, "noacpi")) {
acpi_noirq_set();
return NULL;
}
else if (!strcmp(str, "noearly")) {
pci_probe |= PCI_PROBE_NOEARLY;
return NULL;
}
#ifndef CONFIG_X86_VISWS
else if (!strcmp(str, "usepirqmask")) {
pci_probe |= PCI_USE_PIRQ_MASK;
return NULL;
} else if (!strncmp(str, "irqmask=", 8)) {
pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
return NULL;
} else if (!strncmp(str, "lastbus=", 8)) {
pcibios_last_bus = simple_strtol(str+8, NULL, 0);
return NULL;
}
#endif
else if (!strcmp(str, "rom")) {
pci_probe |= PCI_ASSIGN_ROMS;
return NULL;
} else if (!strcmp(str, "assign-busses")) {
pci_probe |= PCI_ASSIGN_ALL_BUSSES;
return NULL;
} else if (!strcmp(str, "routeirq")) {
pci_routeirq = 1;
return NULL;
}
return str;
}
unsigned int pcibios_assign_all_busses(void)
{
return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
}
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
int err;
if ((err = pcibios_enable_resources(dev, mask)) < 0)
return err;
return pcibios_enable_irq(dev);
}
void pcibios_disable_device (struct pci_dev *dev)
{
pcibios_disable_resources(dev);
if (pcibios_disable_irq)
pcibios_disable_irq(dev);
}