patch-2.3.40 linux/drivers/pci/setup-irq.c

• Lines: 72
• Date: Tue Jan 11 14:22:31 2000
• Orig file: v2.3.39/linux/drivers/pci/setup-irq.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.39/linux/drivers/pci/setup-irq.c linux/drivers/pci/setup-irq.c
@@ -0,0 +1,71 @@
+/*
+ *	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>
+
+
+#define DEBUG_CONFIG 0
+#if DEBUG_CONFIG
+# define DBGC(args)     printk args
+#else
+# define DBGC(args)
+#endif
+
+
+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;
+
+	DBGC(("PCI fixup irq: (%s) got %d\n", dev->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;
+	pci_for_each_dev(dev) {
+		pdev_fixup_irq(dev, swizzle, map_irq);
+	}
+}