kernel-ark/arch/i386/pci/direct.c
Andi Kleen 928cf8c627 [PATCH] i386/x86-64 Fall back to type 1 access when no entry found
When there is no entry for a bus in MCFG fall back to type1.  This is
especially important on K8 systems where always some devices can't be accessed
using mmconfig (in particular the builtin northbridge doesn't support it for
its own devices)

Cc: <gregkh@suse.de>
Cc: <jgarzik@pobox.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 22:31:16 -08:00

290 lines
5.7 KiB
C

/*
* direct.c - Low-level direct PCI config space access
*/
#include <linux/pci.h>
#include <linux/init.h>
#include "pci.h"
/*
* Functions for accessing PCI configuration space with type 1 accesses
*/
#define PCI_CONF1_ADDRESS(bus, devfn, reg) \
(0x80000000 | (bus << 16) | (devfn << 8) | (reg & ~3))
int pci_conf1_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
unsigned long flags;
if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
spin_lock_irqsave(&pci_config_lock, flags);
outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
switch (len) {
case 1:
*value = inb(0xCFC + (reg & 3));
break;
case 2:
*value = inw(0xCFC + (reg & 2));
break;
case 4:
*value = inl(0xCFC);
break;
}
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
int pci_conf1_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value)
{
unsigned long flags;
if ((bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
spin_lock_irqsave(&pci_config_lock, flags);
outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
switch (len) {
case 1:
outb((u8)value, 0xCFC + (reg & 3));
break;
case 2:
outw((u16)value, 0xCFC + (reg & 2));
break;
case 4:
outl((u32)value, 0xCFC);
break;
}
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
#undef PCI_CONF1_ADDRESS
struct pci_raw_ops pci_direct_conf1 = {
.read = pci_conf1_read,
.write = pci_conf1_write,
};
/*
* Functions for accessing PCI configuration space with type 2 accesses
*/
#define PCI_CONF2_ADDRESS(dev, reg) (u16)(0xC000 | (dev << 8) | reg)
static int pci_conf2_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
unsigned long flags;
int dev, fn;
if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
dev = PCI_SLOT(devfn);
fn = PCI_FUNC(devfn);
if (dev & 0x10)
return PCIBIOS_DEVICE_NOT_FOUND;
spin_lock_irqsave(&pci_config_lock, flags);
outb((u8)(0xF0 | (fn << 1)), 0xCF8);
outb((u8)bus, 0xCFA);
switch (len) {
case 1:
*value = inb(PCI_CONF2_ADDRESS(dev, reg));
break;
case 2:
*value = inw(PCI_CONF2_ADDRESS(dev, reg));
break;
case 4:
*value = inl(PCI_CONF2_ADDRESS(dev, reg));
break;
}
outb(0, 0xCF8);
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
static int pci_conf2_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value)
{
unsigned long flags;
int dev, fn;
if ((bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
dev = PCI_SLOT(devfn);
fn = PCI_FUNC(devfn);
if (dev & 0x10)
return PCIBIOS_DEVICE_NOT_FOUND;
spin_lock_irqsave(&pci_config_lock, flags);
outb((u8)(0xF0 | (fn << 1)), 0xCF8);
outb((u8)bus, 0xCFA);
switch (len) {
case 1:
outb((u8)value, PCI_CONF2_ADDRESS(dev, reg));
break;
case 2:
outw((u16)value, PCI_CONF2_ADDRESS(dev, reg));
break;
case 4:
outl((u32)value, PCI_CONF2_ADDRESS(dev, reg));
break;
}
outb(0, 0xCF8);
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
#undef PCI_CONF2_ADDRESS
static struct pci_raw_ops pci_direct_conf2 = {
.read = pci_conf2_read,
.write = pci_conf2_write,
};
/*
* Before we decide to use direct hardware access mechanisms, we try to do some
* trivial checks to ensure it at least _seems_ to be working -- we just test
* whether bus 00 contains a host bridge (this is similar to checking
* techniques used in XFree86, but ours should be more reliable since we
* attempt to make use of direct access hints provided by the PCI BIOS).
*
* This should be close to trivial, but it isn't, because there are buggy
* chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
*/
static int __init pci_sanity_check(struct pci_raw_ops *o)
{
u32 x = 0;
int devfn;
if (pci_probe & PCI_NO_CHECKS)
return 1;
for (devfn = 0; devfn < 0x100; devfn++) {
if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x))
continue;
if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)
return 1;
if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x))
continue;
if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)
return 1;
}
DBG(KERN_WARNING "PCI: Sanity check failed\n");
return 0;
}
static int __init pci_check_type1(void)
{
unsigned long flags;
unsigned int tmp;
int works = 0;
local_irq_save(flags);
outb(0x01, 0xCFB);
tmp = inl(0xCF8);
outl(0x80000000, 0xCF8);
if (inl(0xCF8) == 0x80000000 && pci_sanity_check(&pci_direct_conf1)) {
works = 1;
}
outl(tmp, 0xCF8);
local_irq_restore(flags);
return works;
}
static int __init pci_check_type2(void)
{
unsigned long flags;
int works = 0;
local_irq_save(flags);
outb(0x00, 0xCFB);
outb(0x00, 0xCF8);
outb(0x00, 0xCFA);
if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 &&
pci_sanity_check(&pci_direct_conf2)) {
works = 1;
}
local_irq_restore(flags);
return works;
}
static int __init pci_direct_init(void)
{
struct resource *region, *region2;
if ((pci_probe & PCI_PROBE_CONF1) == 0)
goto type2;
region = request_region(0xCF8, 8, "PCI conf1");
if (!region)
goto type2;
if (pci_check_type1()) {
printk(KERN_INFO "PCI: Using configuration type 1\n");
raw_pci_ops = &pci_direct_conf1;
return 0;
}
release_resource(region);
type2:
if ((pci_probe & PCI_PROBE_CONF2) == 0)
goto out;
region = request_region(0xCF8, 4, "PCI conf2");
if (!region)
goto out;
region2 = request_region(0xC000, 0x1000, "PCI conf2");
if (!region2)
goto fail2;
if (pci_check_type2()) {
printk(KERN_INFO "PCI: Using configuration type 2\n");
raw_pci_ops = &pci_direct_conf2;
return 0;
}
release_resource(region2);
fail2:
release_resource(region);
out:
return 0;
}
arch_initcall(pci_direct_init);