[ACPI] suspend/resume ACPI PCI Interrupt Links

Add reference count and disable ACPI PCI Interrupt Link
when no device still uses it.

Warn when drivers have not released Link at suspend time.

http://bugzilla.kernel.org/show_bug.cgi?id=3469

Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/i386/pci/acpi.c

@@ -30,6 +30,7 @@ static int __init pci_acpi_init(void)
 	acpi_irq_penalty_init();
 	pcibios_scanned++;
 	pcibios_enable_irq = acpi_pci_irq_enable;
+	pcibios_disable_irq = acpi_pci_irq_disable;
 
 	if (pci_routeirq) {
 		/*

arch/i386/pci/common.c

@@ -249,3 +249,9 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
 
 	return pcibios_enable_irq(dev);
 }
+
+void pcibios_disable_device (struct pci_dev *dev)
+{
+	if (pcibios_disable_irq)
+		pcibios_disable_irq(dev);
+}

arch/i386/pci/irq.c

@@ -56,6 +56,7 @@ struct irq_router_handler {
 };
 
 int (*pcibios_enable_irq)(struct pci_dev *dev) = NULL;
+void (*pcibios_disable_irq)(struct pci_dev *dev) = NULL;
 
 /*
  *  Search 0xf0000 -- 0xfffff for the PCI IRQ Routing Table.

arch/i386/pci/pci.h

@@ -72,3 +72,4 @@ extern int pcibios_scanned;
 extern spinlock_t pci_config_lock;
 
 extern int (*pcibios_enable_irq)(struct pci_dev *dev);
+extern void (*pcibios_disable_irq)(struct pci_dev *dev);

drivers/acpi/pci_irq.c

@@ -269,7 +269,51 @@ acpi_pci_irq_del_prt (int segment, int bus)
 /* --------------------------------------------------------------------------
                           PCI Interrupt Routing Support
    -------------------------------------------------------------------------- */
+typedef int (*irq_lookup_func)(struct acpi_prt_entry *, int *, int *, char **);
 
+static int
+acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
+	int	*edge_level,
+	int	*active_high_low,
+	char	**link)
+{
+	int	irq;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_allocate_irq");
+
+	if (entry->link.handle) {
+		irq = acpi_pci_link_allocate_irq(entry->link.handle,
+			entry->link.index, edge_level, active_high_low, link);
+		if (irq < 0) {
+			ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));
+			return_VALUE(-1);
+		}
+	} else {
+		irq = entry->link.index;
+		*edge_level = ACPI_LEVEL_SENSITIVE;
+		*active_high_low = ACPI_ACTIVE_LOW;
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
+	return_VALUE(irq);
+}
+
+static int
+acpi_pci_free_irq(struct acpi_prt_entry *entry,
+	int	*edge_level,
+	int	*active_high_low,
+	char	**link)
+{
+	int	irq;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_free_irq");
+	if (entry->link.handle) {
+		irq = acpi_pci_link_free_irq(entry->link.handle);
+	} else {
+		irq = entry->link.index;
+	}
+	return_VALUE(irq);
+}
 /*
  * acpi_pci_irq_lookup
  * success: return IRQ >= 0
@@ -282,12 +326,13 @@ acpi_pci_irq_lookup (
 	int			pin,
 	int			*edge_level,
 	int			*active_high_low,
-	char			**link)
+	char			**link,
+	irq_lookup_func		func)
 {
 	struct acpi_prt_entry	*entry = NULL;
 	int segment = pci_domain_nr(bus);
 	int bus_nr = bus->number;
-	int irq;
+	int ret;
 
 	ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
 
@@ -301,22 +346,8 @@ acpi_pci_irq_lookup (
 		return_VALUE(-1);
 	}
 
-	if (entry->link.handle) {
-		irq = acpi_pci_link_get_irq(entry->link.handle,
-			entry->link.index, edge_level, active_high_low, link);
-		if (irq < 0) {
-			ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));
-			return_VALUE(-1);
-		}
-	} else {
-		irq = entry->link.index;
-		*edge_level = ACPI_LEVEL_SENSITIVE;
-		*active_high_low = ACPI_ACTIVE_LOW;
-	}
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
-
-	return_VALUE(irq);
+	ret = func(entry, edge_level, active_high_low, link);
+	return_VALUE(ret);
 }
 
 /*
@@ -330,7 +361,8 @@ acpi_pci_irq_derive (
 	int			pin,
 	int			*edge_level,
 	int			*active_high_low,
-	char			**link)
+	char			**link,
+	irq_lookup_func		func)
 {
 	struct pci_dev		*bridge = dev;
 	int			irq = -1;
@@ -363,7 +395,7 @@ acpi_pci_irq_derive (
 		}
 
 		irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
-			pin, edge_level, active_high_low, link);
+			pin, edge_level, active_high_low, link, func);
 	}
 
 	if (irq < 0) {
@@ -415,15 +447,15 @@ acpi_pci_irq_enable (
 	 * values override any BIOS-assigned IRQs set during boot.
 	 */
  	irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
-		&edge_level, &active_high_low, &link);
+		&edge_level, &active_high_low, &link, acpi_pci_allocate_irq);
 
 	/*
 	 * If no PRT entry was found, we'll try to derive an IRQ from the
 	 * device's parent bridge.
 	 */
 	if (irq < 0)
  		irq = acpi_pci_irq_derive(dev, pin, &edge_level,
-			&active_high_low, &link);
+			&active_high_low, &link, acpi_pci_allocate_irq);
 
 	/*
 	 * No IRQ known to the ACPI subsystem - maybe the BIOS / 
@@ -461,7 +493,9 @@ acpi_pci_irq_enable (
 EXPORT_SYMBOL(acpi_pci_irq_enable);
 
 
-#ifdef CONFIG_ACPI_DEALLOCATE_IRQ
+/* FIXME: implement x86/x86_64 version */
+void __attribute__((weak)) acpi_unregister_gsi(u32 i) {}
+
 void
 acpi_pci_irq_disable (
 	struct pci_dev		*dev)
@@ -488,14 +522,14 @@ acpi_pci_irq_disable (
 	 * First we check the PCI IRQ routing table (PRT) for an IRQ.
 	 */
  	gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
-				  &edge_level, &active_high_low, NULL);
+			&edge_level, &active_high_low, NULL, acpi_pci_free_irq);
 	/*
 	 * If no PRT entry was found, we'll try to derive an IRQ from the
 	 * device's parent bridge.
 	 */
 	if (gsi < 0)
  		gsi = acpi_pci_irq_derive(dev, pin,
-					  &edge_level, &active_high_low, NULL);
+			&edge_level, &active_high_low, NULL, acpi_pci_free_irq);
 	if (gsi < 0)
 		return_VOID;
 
@@ -511,4 +545,3 @@ acpi_pci_irq_disable (
 
 	return_VOID;
 }
-#endif /* CONFIG_ACPI_DEALLOCATE_IRQ */