[RFC Patch V2 15/16] pci, ioapic: kill ioapic PCI driver

[Jiang Liu]

Originally the ioapic PCI driver is designed to support IOAPIC hotplug,
but it never works because no architecture has implemented required
interface to support it. We plan to reimplement it as an ACPI driver
instead of PCI driver due to:
1) To support IOAPIC hotplug, an IOAPIC unit must have an companion
   ACPI device, but it may or may not be presented in PCI domain.
2) All other PCI devices have dependency on IOAPIC, so we must hot-add
   it before all other PCI devices and hot-remove it after all other
   PCI devices. So we need to explicitly control the order to add/remove
   IOAPIC devices.

So kill the ioapic PCI driver and will reimplement it as an ACPI driver.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
 drivers/pci/Kconfig  |    7 ---
 drivers/pci/Makefile |    2 -
 drivers/pci/ioapic.c |  121 --------------------------------------------------
 3 files changed, 130 deletions(-)
 delete mode 100644 drivers/pci/ioapic.c

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 893503fa1782..39866d18004e 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -104,13 +104,6 @@ config PCI_PASID
 
 	  If unsure, say N.
 
-config PCI_IOAPIC
-	bool "PCI IO-APIC hotplug support" if X86
-	depends on PCI
-	depends on ACPI
-	depends on X86_IO_APIC
-	default !X86
-
 config PCI_LABEL
 	def_bool y if (DMI || ACPI)
 	select NLS
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index e04fe2d9df3b..73e4af400a5a 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -13,8 +13,6 @@ obj-$(CONFIG_PCI_QUIRKS) += quirks.o
 # Build PCI Express stuff if needed
 obj-$(CONFIG_PCIEPORTBUS) += pcie/
 
-obj-$(CONFIG_PCI_IOAPIC) += ioapic.o
-
 # Build the PCI Hotplug drivers if we were asked to
 obj-$(CONFIG_HOTPLUG_PCI) += hotplug/
 ifdef CONFIG_HOTPLUG_PCI
diff --git a/drivers/pci/ioapic.c b/drivers/pci/ioapic.c
deleted file mode 100644
index 6b2b7dddbbdb..000000000000
--- a/drivers/pci/ioapic.c
+++ /dev/null
@@ -1,121 +0,0 @@
-/*
- * IOAPIC/IOxAPIC/IOSAPIC driver
- *
- * Copyright (C) 2009 Fujitsu Limited.
- * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-/*
- * This driver manages PCI I/O APICs added by hotplug after boot.  We try to
- * claim all I/O APIC PCI devices, but those present at boot were registered
- * when we parsed the ACPI MADT, so we'll fail when we try to re-register
- * them.
- */
-
-#include <linux/pci.h>
-#include <linux/module.h>
-#include <linux/acpi.h>
-#include <linux/slab.h>
-
-struct ioapic {
-	acpi_handle	handle;
-	u32		gsi_base;
-};
-
-static int ioapic_probe(struct pci_dev *dev, const struct pci_device_id *ent)
-{
-	acpi_handle handle;
-	acpi_status status;
-	unsigned long long gsb;
-	struct ioapic *ioapic;
-	int ret;
-	char *type;
-	struct resource *res;
-
-	handle = ACPI_HANDLE(&dev->dev);
-	if (!handle)
-		return -EINVAL;
-
-	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.
-	 */
-
-	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
-	if (!ioapic)
-		return -ENOMEM;
-
-	ioapic->handle = handle;
-	ioapic->gsi_base = (u32) gsb;
-
-	if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
-		type = "IOAPIC";
-	else
-		type = "IOxAPIC";
-
-	ret = pci_enable_device(dev);
-	if (ret < 0)
-		goto exit_free;
-
-	pci_set_master(dev);
-
-	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))
-		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;
-
-exit_release:
-	pci_release_region(dev, 0);
-exit_disable:
-	pci_disable_device(dev);
-exit_free:
-	kfree(ioapic);
-	return -ENODEV;
-}
-
-static void ioapic_remove(struct pci_dev *dev)
-{
-	struct ioapic *ioapic = pci_get_drvdata(dev);
-
-	acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base);
-	pci_release_region(dev, 0);
-	pci_disable_device(dev);
-	kfree(ioapic);
-}
-
-
-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);
-
-static struct pci_driver ioapic_driver = {
-	.name		= "ioapic",
-	.id_table	= ioapic_devices,
-	.probe		= ioapic_probe,
-	.remove		= ioapic_remove,
-};
-
-static int __init ioapic_init(void)
-{
-	return pci_register_driver(&ioapic_driver);
-}
-module_init(ioapic_init);
-
-MODULE_LICENSE("GPL");
-- 
1.7.10.4

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