tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * drivers/pci/setup-irq.c
3 *
4 * Extruded from code written by
5 * Dave Rusling (david.rusling@reo.mts.dec.com)
6 * David Mosberger (davidm@cs.arizona.edu)
7 * David Miller (davem@redhat.com)
8 *
9 * Support routines for initializing a PCI subsystem.
10 */
11
12
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/pci.h>
16#include <linux/errno.h>
17#include <linux/ioport.h>
18#include <linux/cache.h>
19
20void __weak pcibios_update_irq(struct pci_dev *dev, int irq)
21{
22 dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq);
23 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
24}
25
26static void
27pdev_fixup_irq(struct pci_dev *dev,
28 u8 (*swizzle)(struct pci_dev *, u8 *),
29 int (*map_irq)(const struct pci_dev *, u8, u8))
30{
31 u8 pin, slot;
32 int irq = 0;
33
34 /* If this device is not on the primary bus, we need to figure out
35 which interrupt pin it will come in on. We know which slot it
36 will come in on 'cos that slot is where the bridge is. Each
37 time the interrupt line passes through a PCI-PCI bridge we must
38 apply the swizzle function. */
39
40 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
41 /* Cope with illegal. */
42 if (pin > 4)
43 pin = 1;
44
45 if (pin != 0) {
46 /* Follow the chain of bridges, swizzling as we go. */
47 slot = (*swizzle)(dev, &pin);
48
49 irq = (*map_irq)(dev, slot, pin);
50 if (irq == -1)
51 irq = 0;
52 }
53 dev->irq = irq;
54
55 dev_dbg(&dev->dev, "fixup irq: got %d\n", dev->irq);
56
57 /* Always tell the device, so the driver knows what is
58 the real IRQ to use; the device does not use it. */
59 pcibios_update_irq(dev, irq);
60}
61
62void
63pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
64 int (*map_irq)(const struct pci_dev *, u8, u8))
65{
66 struct pci_dev *dev = NULL;
67 for_each_pci_dev(dev)
68 pdev_fixup_irq(dev, swizzle, map_irq);
69}