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#include <linux/pci.h>
#include <linux/kernel.h>
static int __init
early_read_config_word(struct pci_channel *hose,
int top_bus, int bus, int devfn, int offset, u16 *value)
{
struct pci_dev fake_dev;
struct pci_bus fake_bus;
fake_dev.bus = &fake_bus;
fake_dev.sysdata = hose;
fake_dev.devfn = devfn;
fake_bus.number = bus;
fake_bus.sysdata = hose;
fake_bus.ops = hose->pci_ops;
if (bus != top_bus)
/* Fake a parent bus structure. */
fake_bus.parent = &fake_bus;
else
fake_bus.parent = NULL;
return pci_read_config_word(&fake_dev, offset, value);
}
int __init pci_is_66mhz_capable(struct pci_channel *hose,
int top_bus, int current_bus)
{
u32 pci_devfn;
unsigned short vid;
int cap66 = -1;
u16 stat;
printk(KERN_INFO "PCI: Checking 66MHz capabilities...\n");
for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
if (PCI_FUNC(pci_devfn))
continue;
if (early_read_config_word(hose, top_bus, current_bus,
pci_devfn, PCI_VENDOR_ID, &vid) !=
PCIBIOS_SUCCESSFUL)
continue;
if (vid == 0xffff)
continue;
/* check 66MHz capability */
if (cap66 < 0)
cap66 = 1;
if (cap66) {
early_read_config_word(hose, top_bus, current_bus,
pci_devfn, PCI_STATUS, &stat);
if (!(stat & PCI_STATUS_66MHZ)) {
printk(KERN_DEBUG
"PCI: %02x:%02x not 66MHz capable.\n",
current_bus, pci_devfn);
cap66 = 0;
break;
}
}
}
return cap66 > 0;
}
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