alistair23-linux/drivers/pci/setup-irq.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

65 lines
1.6 KiB
C

/*
* drivers/pci/setup-irq.c
*
* Extruded from code written by
* Dave Rusling (david.rusling@reo.mts.dec.com)
* David Mosberger (davidm@cs.arizona.edu)
* David Miller (davem@redhat.com)
*
* Support routines for initializing a PCI subsystem.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
static void __init
pdev_fixup_irq(struct pci_dev *dev,
u8 (*swizzle)(struct pci_dev *, u8 *),
int (*map_irq)(struct pci_dev *, u8, u8))
{
u8 pin, slot;
int irq;
/* If this device is not on the primary bus, we need to figure out
which interrupt pin it will come in on. We know which slot it
will come in on 'cos that slot is where the bridge is. Each
time the interrupt line passes through a PCI-PCI bridge we must
apply the swizzle function. */
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
/* Cope with 0 and illegal. */
if (pin == 0 || pin > 4)
pin = 1;
/* Follow the chain of bridges, swizzling as we go. */
slot = (*swizzle)(dev, &pin);
irq = (*map_irq)(dev, slot, pin);
if (irq == -1)
irq = 0;
dev->irq = irq;
pr_debug("PCI: fixup irq: (%s) got %d\n",
dev->dev.kobj.name, dev->irq);
/* Always tell the device, so the driver knows what is
the real IRQ to use; the device does not use it. */
pcibios_update_irq(dev, irq);
}
void __init
pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
int (*map_irq)(struct pci_dev *, u8, u8))
{
struct pci_dev *dev = NULL;
while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
pdev_fixup_irq(dev, swizzle, map_irq);
}
}