1 files changed, 68 insertions, 0 deletions
diff --git a/kernel/drivers/pci/setup-irq.c b/kernel/drivers/pci/setup-irq.c
new file mode 100644
index 000000000..95c225be4
--- /dev/null
+++ b/kernel/drivers/pci/setup-irq.c
@@ -0,0 +1,68 @@
+/*
+ *	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/kernel.h>
+#include <linux/pci.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/cache.h>
+
+void __weak pcibios_update_irq(struct pci_dev *dev, int irq)
+{
+	dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq);
+	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
+}
+
+static void pdev_fixup_irq(struct pci_dev *dev,
+			   u8 (*swizzle)(struct pci_dev *, u8 *),
+			   int (*map_irq)(const struct pci_dev *, u8, u8))
+{
+	u8 pin, slot;
+	int irq = 0;
+
+	/* 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 illegal. */
+	if (pin > 4)
+		pin = 1;
+
+	if (pin != 0) {
+		/* 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;
+
+	dev_dbg(&dev->dev, "fixup irq: got %d\n", 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 pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
+		    int (*map_irq)(const struct pci_dev *, u8, u8))
+{
+	struct pci_dev *dev = NULL;
+
+	for_each_pci_dev(dev)
+		pdev_fixup_irq(dev, swizzle, map_irq);
+}
+EXPORT_SYMBOL_GPL(pci_fixup_irqs);