[PATCH v2 26-3/26] PCI, x86, ACPI: Enable ioapic hotplug support with acpi host bridge.

[Yinghai Lu <yinghai@kernel.org>]

We need to have ioapic setup before normal pci drivers.
otherwise other pci driver can not setup irq.

So we should not treat them as normal pci devices.
Also we will need to support ioapic hotplug without pci device around.

We need to call ioapic add/remove during host-bridge add/remove.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/acpi/pci_root.c  |    4 +
 drivers/pci/ioapic.c     |  147 ++++++++++++++++++++++++++++++-----------------
 include/linux/pci-acpi.h |    9 ++
 3 files changed, 107 insertions(+), 53 deletions(-)

Index: linux-2.6/drivers/pci/ioapic.c
===================================================================
--- linux-2.6.orig/drivers/pci/ioapic.c
+++ linux-2.6/drivers/pci/ioapic.c
@@ -22,70 +22,77 @@
 #include <linux/slab.h>
 #include <acpi/acpi_bus.h>
 
-struct ioapic {
-	acpi_handle	handle;
+struct acpi_pci_ioapic {
+	acpi_handle	root_handle;
 	u32		gsi_base;
+	struct pci_dev *pdev;
+	struct list_head list;
 };
 
-static int ioapic_probe(struct pci_dev *dev, const struct pci_device_id *ent)
+static LIST_HEAD(ioapic_list);
+static DEFINE_MUTEX(ioapic_list_lock);
+
+static void handle_ioapic_add(acpi_handle handle, struct pci_dev **pdev,
+				 u32 *pgsi_base)
 {
-	acpi_handle handle;
 	acpi_status status;
 	unsigned long long gsb;
-	struct ioapic *ioapic;
+	struct pci_dev *dev;
+	u32 gsi_base;
 	int ret;
 	char *type;
-	struct resource *res;
+	struct resource r;
+	struct resource *res = &r;
+	char objname[64];
+	struct acpi_buffer buffer = {sizeof(objname), objname};
 
-	handle = DEVICE_ACPI_HANDLE(&dev->dev);
-	if (!handle)
-		return -EINVAL;
+	*pdev = NULL;
+	*pgsi_base = 0;
 
 	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsb);
-	if (ACPI_FAILURE(status))
-		return -EINVAL;
-
-	/*
-	 * The previous code in acpiphp evaluated _MAT if _GSB failed, but
-	 * ACPI spec 4.0 sec 6.2.2 requires _GSB for hot-pluggable I/O APICs.
-	 */
+	if (ACPI_FAILURE(status) || !gsb)
+		return;
 
-	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
-	if (!ioapic)
-		return -ENOMEM;
+	dev = acpi_get_pci_dev(handle);
+	if (!dev)
+		return;
 
-	ioapic->handle = handle;
-	ioapic->gsi_base = (u32) gsb;
+	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 
-	if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
-		type = "IOAPIC";
-	else
-		type = "IOxAPIC";
+	gsi_base = gsb;
+	type = "IOxAPIC";
 
 	ret = pci_enable_device(dev);
 	if (ret < 0)
-		goto exit_free;
+		goto exit_put;
 
 	pci_set_master(dev);
 
+	if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
+		type = "IOAPIC";
+
 	if (pci_request_region(dev, 0, type))
 		goto exit_disable;
 
 	res = &dev->resource[0];
-	if (acpi_register_ioapic(ioapic->handle, res->start, ioapic->gsi_base))
+
+	if (acpi_register_ioapic(handle, res->start, gsi_base))
 		goto exit_release;
 
-	pci_set_drvdata(dev, ioapic);
-	dev_info(&dev->dev, "%s at %pR, GSI %u\n", type, res, ioapic->gsi_base);
-	return 0;
+	pr_info("%s %s %s at %pR, GSI %u\n",
+		dev_name(&dev->dev), objname, type,
+		res, gsi_base);
+
+	*pdev = dev;
+	*pgsi_base = gsi_base;
+	return;
 
 exit_release:
 	pci_release_region(dev, 0);
 exit_disable:
 	pci_disable_device(dev);
-exit_free:
-	kfree(ioapic);
-	return -ENODEV;
+exit_put:
+	pci_dev_put(dev);
 }
 
 static void pci_disable_device_mem(struct pci_dev *dev)
@@ -99,37 +106,71 @@ static void pci_disable_device_mem(struc
 	}
 }
 
-static void ioapic_remove(struct pci_dev *dev)
+static void handle_ioapic_remove(acpi_handle handle, struct pci_dev *dev,
+				  u32 gsi_base)
 {
-	struct ioapic *ioapic = pci_get_drvdata(dev);
+	acpi_unregister_ioapic(handle, gsi_base);
 
-	acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base);
 	pci_release_region(dev, 0);
 	pci_disable_device(dev);
 	/* need to disable it, otherwise remove/rescan will not work */
 	pci_disable_device_mem(dev);
-	kfree(ioapic);
+	pci_dev_put(dev);
 }
 
+static acpi_status register_ioapic(acpi_handle handle, u32 lvl,
+					void *context, void **rv)
+{
+	acpi_handle root_handle = context;
+	struct pci_dev *pdev;
+	u32 gsi_base;
+	struct acpi_pci_ioapic *ioapic;
+
+	handle_ioapic_add(handle, &pdev, &gsi_base);
+	if (!gsi_base)
+		return AE_OK;
 
-static DEFINE_PCI_DEVICE_TABLE(ioapic_devices) = {
-	{ PCI_DEVICE_CLASS(PCI_CLASS_SYSTEM_PIC_IOAPIC, ~0) },
-	{ PCI_DEVICE_CLASS(PCI_CLASS_SYSTEM_PIC_IOXAPIC, ~0) },
-	{ }
-};
-MODULE_DEVICE_TABLE(pci, ioapic_devices);
+	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
+	if (!ioapic) {
+		pr_err("%s: cannot allocate memory\n", __func__);
+		handle_ioapic_remove(root_handle, pdev, gsi_base);
+		return AE_OK;
+	}
+	ioapic->root_handle = root_handle;
+	ioapic->pdev = pdev;
+	ioapic->gsi_base = gsi_base;
+
+	mutex_lock(&ioapic_list_lock);
+	list_add(&ioapic->list, &ioapic_list);
+	mutex_unlock(&ioapic_list_lock);
 
-static struct pci_driver ioapic_driver = {
-	.name		= "ioapic",
-	.id_table	= ioapic_devices,
-	.probe		= ioapic_probe,
-	.remove		= ioapic_remove,
-};
+	return AE_OK;
+}
 
-static int __init ioapic_init(void)
+void acpi_pci_ioapic_add(struct acpi_pci_root *root)
 {
-	return pci_register_driver(&ioapic_driver);
+	acpi_status status;
+
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle,
+				     (u32)1, register_ioapic, NULL,
+				     root->device->handle,
+				     NULL);
+	if (ACPI_FAILURE(status))
+		pr_err("%s: register_ioapic failure - %d", __func__, status);
 }
-module_init(ioapic_init);
 
-MODULE_LICENSE("GPL");
+void acpi_pci_ioapic_remove(struct acpi_pci_root *root)
+{
+	struct acpi_pci_ioapic *ioapic, *tmp;
+
+	mutex_lock(&ioapic_list_lock);
+	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
+		if (root->device->handle != ioapic->root_handle)
+			continue;
+		list_del(&ioapic->list);
+		handle_ioapic_remove(ioapic->root_handle, ioapic->pdev,
+					ioapic->gsi_base);
+		kfree(ioapic);
+	}
+	mutex_unlock(&ioapic_list_lock);
+}
Index: linux-2.6/drivers/acpi/pci_root.c
===================================================================
--- linux-2.6.orig/drivers/acpi/pci_root.c
+++ linux-2.6/drivers/acpi/pci_root.c
@@ -584,6 +584,8 @@ static int acpi_pci_root_add(struct acpi
 		pci_assign_unassigned_bus_resources(root->bus);
 	}
 
+	acpi_pci_ioapic_add(root);
+
 	mutex_lock(&acpi_pci_root_lock);
 	list_for_each_entry(driver, &acpi_pci_drivers, node)
 		if (driver->add)
@@ -623,6 +625,8 @@ static void acpi_pci_root_remove(struct
 			driver->remove(root);
 	mutex_unlock(&acpi_pci_root_lock);
 
+	acpi_pci_ioapic_remove(root);
+
 	device_set_run_wake(root->bus->bridge, false);
 	pci_acpi_remove_bus_pm_notifier(device);
 
Index: linux-2.6/include/linux/pci-acpi.h
===================================================================
--- linux-2.6.orig/include/linux/pci-acpi.h
+++ linux-2.6/include/linux/pci-acpi.h
@@ -41,8 +41,17 @@ static inline acpi_handle acpi_pci_get_b
 
 	return DEVICE_ACPI_HANDLE(dev);
 }
+
+#ifdef CONFIG_PCI_IOAPIC
+void acpi_pci_ioapic_add(struct acpi_pci_root *root);
+void acpi_pci_ioapic_remove(struct acpi_pci_root *root);
+#else
+static inline void acpi_pci_ioapic_add(struct acpi_pci_root *root) { }
+static inline void acpi_pci_ioapic_remove(struct acpi_pci_root *root) { }
 #endif
 
+#endif /* CONFIG_ACPI */
+
 #ifdef CONFIG_ACPI_APEI
 extern bool aer_acpi_firmware_first(void);
 #else