1 files changed, 110 insertions, 0 deletions
diff --git a/arch/i386/pci/visws.c b/arch/i386/pci/visws.c
new file mode 100644
index 00000000000..6a924878443
--- /dev/null
+++ b/arch/i386/pci/visws.c
@@ -0,0 +1,110 @@
+/*
+ *	Low-Level PCI Support for SGI Visual Workstation
+ *
+ *	(c) 1999--2000 Martin Mares <mj@ucw.cz>
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+
+#include "cobalt.h"
+#include "lithium.h"
+
+#include "pci.h"
+
+
+extern struct pci_raw_ops pci_direct_conf1;
+
+static int pci_visws_enable_irq(struct pci_dev *dev) { return 0; }
+
+int (*pcibios_enable_irq)(struct pci_dev *dev) = &pci_visws_enable_irq;
+
+void __init pcibios_penalize_isa_irq(int irq) {}
+
+
+unsigned int pci_bus0, pci_bus1;
+
+static inline u8 bridge_swizzle(u8 pin, u8 slot) 
+{
+	return (((pin - 1) + slot) % 4) + 1;
+}
+
+static u8 __init visws_swizzle(struct pci_dev *dev, u8 *pinp)
+{
+	u8 pin = *pinp;
+
+	while (dev->bus->self) {	/* Move up the chain of bridges. */
+		pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
+		dev = dev->bus->self;
+	}
+	*pinp = pin;
+
+	return PCI_SLOT(dev->devfn);
+}
+
+static int __init visws_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
+{
+	int irq, bus = dev->bus->number;
+
+	pin--;
+
+	/* Nothing useful at PIIX4 pin 1 */
+	if (bus == pci_bus0 && slot == 4 && pin == 0)
+		return -1;
+
+	/* PIIX4 USB is on Bus 0, Slot 4, Line 3 */
+	if (bus == pci_bus0 && slot == 4 && pin == 3) {
+		irq = CO_IRQ(CO_APIC_PIIX4_USB);
+		goto out;
+	}
+
+	/* First pin spread down 1 APIC entry per slot */
+	if (pin == 0) {
+		irq = CO_IRQ((bus == pci_bus0 ? CO_APIC_PCIB_BASE0 :
+						CO_APIC_PCIA_BASE0) + slot);
+		goto out;
+	}
+
+	/* lines 1,2,3 from any slot is shared in this twirly pattern */
+	if (bus == pci_bus1) {
+		/* lines 1-3 from devices 0 1 rotate over 2 apic entries */
+		irq = CO_IRQ(CO_APIC_PCIA_BASE123 + ((slot + (pin - 1)) % 2));
+	} else { /* bus == pci_bus0 */
+		/* lines 1-3 from devices 0-3 rotate over 3 apic entries */
+		if (slot == 0)
+			slot = 3; /* same pattern */
+		irq = CO_IRQ(CO_APIC_PCIA_BASE123 + ((3 - slot) + (pin - 1) % 3));
+	}
+out:
+	printk(KERN_DEBUG "PCI: Bus %d Slot %d Line %d -> IRQ %d\n", bus, slot, pin, irq);
+	return irq;
+}
+
+void __init pcibios_update_irq(struct pci_dev *dev, int irq)
+{
+	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
+}
+
+static int __init pcibios_init(void)
+{
+	/* The VISWS supports configuration access type 1 only */
+	pci_probe = (pci_probe | PCI_PROBE_CONF1) &
+		    ~(PCI_PROBE_BIOS | PCI_PROBE_CONF2);
+
+	pci_bus0 = li_pcib_read16(LI_PCI_BUSNUM) & 0xff;
+	pci_bus1 = li_pcia_read16(LI_PCI_BUSNUM) & 0xff;
+
+	printk(KERN_INFO "PCI: Lithium bridge A bus: %u, "
+		"bridge B (PIIX4) bus: %u\n", pci_bus1, pci_bus0);
+
+	raw_pci_ops = &pci_direct_conf1;
+	pci_scan_bus(pci_bus0, &pci_root_ops, NULL);
+	pci_scan_bus(pci_bus1, &pci_root_ops, NULL);
+	pci_fixup_irqs(visws_swizzle, visws_map_irq);
+	pcibios_resource_survey();
+	return 0;
+}
+
+subsys_initcall(pcibios_init);