Properly (?) handle the multiple people who can find PCI root bridges

arch/i386/pci/acpi.c

@@ -2,73 +2,23 @@
 #include <linux/acpi.h>
 #include "pci.h"
 
-extern void eisa_set_level_irq(int irq);
-
-static int acpi_lookup_irq (
-	struct pci_dev		*dev,
-	int			assign)
+static int __init pci_acpi_init(void)
 {
-	int			result = 0;
-	int			irq = 0;
-	u8			pin;
-
-	/* TBD: Select IRQ from possible to improve routing performance. */
-
-	/* Find IRQ pin */
-	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
-	if (!pin) {
-		DBG(" -> no interrupt pin\n");
+	if (pcibios_scanned)
 		return 0;
-	}
-	pin = pin - 1;
-
-	result = acpi_prt_get_irq(dev, pin, &irq);
-	if (!irq)
-		result = -ENODEV;
-	if (0 != result) {
-		printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s\n",
-		       'A'+pin, dev->slot_name);
-		return result;
-	}
-
-	/* only check for the IRQ */
-	if (!assign) {
-		printk(KERN_INFO "PCI: Found IRQ %d for device %s\n", 
-		       irq, dev->slot_name);
-		return 1;
-	}
-
-	dev->irq = irq;
 
-	/* also assign an IRQ */
-	if (irq && (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
-		result = acpi_prt_set_irq(dev, pin, irq);
-		if (0 != result) {
-			printk(KERN_WARNING "PCI: Could not assign IRQ %d to device %s\n", irq, dev->slot_name);
-			return result;
-		}
-
-		eisa_set_level_irq(irq);
-
-		printk(KERN_INFO "PCI: Assigned IRQ %d for device %s\n", irq, dev->slot_name);
-	}
-
-	return 1;
-}
-
-static int __init pci_acpi_init(void)
-{
 	if (!(pci_probe & PCI_NO_ACPI_ROUTING)) {
-		if (acpi_prts.count) {
+		if (!acpi_pci_irq_init()) {
 			printk(KERN_INFO "PCI: Using ACPI for IRQ routing\n");
 			printk(KERN_INFO "PCI: if you experience problems, try using option 'pci=noacpi'\n");
-			pci_use_acpi_routing = 1;
-			pci_lookup_irq = acpi_lookup_irq;
+			pcibios_scanned++;
+			pcibios_enable_irq = acpi_pci_irq_enable;
 		} else
 			printk(KERN_WARNING "PCI: Invalid ACPI-PCI IRQ routing table\n");
 
 	}
+
 	return 0;
 }
 
-arch_initcall(pci_acpi_init);
+subsys_initcall(pci_acpi_init);

arch/i386/pci/common.c

@@ -27,6 +27,12 @@ struct pci_ops *pci_root_ops = NULL;
 int (*pci_config_read)(int seg, int bus, int dev, int fn, int reg, int len, u32 *value) = NULL;
 int (*pci_config_write)(int seg, int bus, int dev, int fn, int reg, int len, u32 value) = NULL;
 
+/*
+ * legacy, numa, and acpi all want to call pcibios_scan_root
+ * from their initcalls. This flag prevents that.
+ */
+int pcibios_scanned;
+
 /*
  * This interrupt-safe spinlock protects all accesses to PCI
  * configuration space.
@@ -201,6 +207,6 @@ int pcibios_enable_device(struct pci_dev *dev)
 
 	if ((err = pcibios_enable_resources(dev)) < 0)
 		return err;
-	pcibios_enable_irq(dev);
-	return 0;
+
+	return pcibios_enable_irq(dev);
 }

arch/i386/pci/irq.c

@@ -12,7 +12,6 @@
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
-#include <linux/acpi.h>
 #include <asm/io.h>
 #include <asm/smp.h>
 #include <asm/io_apic.h>
@@ -22,7 +21,6 @@
 #define PIRQ_SIGNATURE	(('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24))
 #define PIRQ_VERSION 0x0100
 
-int pci_use_acpi_routing = 0;
 int broken_hp_bios_irq9;
 
 static struct irq_routing_table *pirq_table;
@@ -46,7 +44,7 @@ struct irq_router {
 	int (*set)(struct pci_dev *router, struct pci_dev *dev, int pirq, int new);
 };
 
-int (*pci_lookup_irq)(struct pci_dev * dev, int assign) = NULL;
+int (*pcibios_enable_irq)(struct pci_dev *dev) = NULL;
 
 /*
  *  Search 0xf0000 -- 0xfffff for the PCI IRQ Routing Table.
@@ -690,7 +688,7 @@ static int __init pcibios_irq_init(void)
 {
 	DBG("PCI: IRQ init\n");
 
-	if (pci_lookup_irq)
+	if (pcibios_enable_irq)
 		return 0;
 
 	pirq_table = pirq_find_routing_table();
@@ -712,7 +710,9 @@ static int __init pcibios_irq_init(void)
 		if (io_apic_assign_pci_irqs)
 			pirq_table = NULL;
 	}
-	pci_lookup_irq = pcibios_lookup_irq;
+
+	pcibios_enable_irq = pirq_enable_irq;
+
 	pcibios_fixup_irqs();
 	return 0;
 }
@@ -781,7 +781,7 @@ void __init pcibios_fixup_irqs(void)
 		 * Still no IRQ? Try to lookup one...
 		 */
 		if (pin && !dev->irq)
-			pci_lookup_irq(dev, 0);
+			pcibios_lookup_irq(dev, 0);
 	}
 }
 
@@ -794,11 +794,11 @@ void pcibios_penalize_isa_irq(int irq)
 	pirq_penalty[irq] += 100;
 }
 
-void pcibios_enable_irq(struct pci_dev *dev)
+int pirq_enable_irq(struct pci_dev *dev)
 {
 	u8 pin;
 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
-	if (pin && !pci_lookup_irq(dev, 1) && !dev->irq) {
+	if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
 		char *msg;
 		if (io_apic_assign_pci_irqs)
 			msg = " Probably buggy MP table.";
@@ -809,4 +809,6 @@ void pcibios_enable_irq(struct pci_dev *dev)
 		printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
 		       'A' + pin - 1, dev->slot_name, msg);
 	}
+
+	return 0;
 }

arch/i386/pci/legacy.c

@@ -42,11 +42,14 @@ static int __init pci_legacy_init(void)
 		return 0;
 	}
 
+	if (pcibios_scanned++)
+		return 0;
+
 	printk("PCI: Probing PCI hardware\n");
 	pci_root_bus = pcibios_scan_root(0);
 
-	if (!pci_use_acpi_routing)
-		pcibios_fixup_peer_bridges();
+	pcibios_fixup_peer_bridges();
+
 	return 0;
 }
 

arch/i386/pci/numa.c

@@ -104,6 +104,9 @@ static int __init pci_numa_init(void)
 	pci_config_read = pci_conf1_read;
 	pci_config_write = pci_conf1_write;
 
+	if (pcibios_scanned++)
+		return 0;
+
 	pci_root_bus = pcibios_scan_root(0);
 	if (clustered_apic_mode && (numnodes > 1)) {
 		for (quad = 1; quad < numnodes; ++quad) {

arch/i386/pci/pci.h

@@ -66,10 +66,10 @@ struct irq_routing_table {
 
 extern unsigned int pcibios_irq_mask;
 
-extern int pci_use_acpi_routing;
+extern int pcibios_scanned;
 extern spinlock_t pci_config_lock;
 
 void pcibios_fixup_irqs(void);
-void pcibios_enable_irq(struct pci_dev *dev);
+int pirq_enable_irq(struct pci_dev *dev);
 
-extern int (*pci_lookup_irq)(struct pci_dev * dev, int assign);
+extern int (*pcibios_enable_irq)(struct pci_dev *dev);