drivers/pci/ioapic.c

   1 /*
   2  * IOAPIC/IOxAPIC/IOSAPIC driver
   3  *
   4  * Copyright (C) 2009 Fujitsu Limited.
   5  * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 /*
  13  * This driver manages PCI I/O APICs added by hotplug after boot.  We try to
  14  * claim all I/O APIC PCI devices, but those present at boot were registered
  15  * when we parsed the ACPI MADT, so we'll fail when we try to re-register
  16  * them.
  17  */
  18
  19 #include <linux/pci.h>
  20 #include <linux/module.h>
  21 #include <linux/acpi.h>
  22 #include <linux/slab.h>
  23 #include <acpi/acpi_bus.h>
  24
  25 struct ioapic {
  26         acpi_handle     handle;
  27         u32             gsi_base;
  28 };
  29
  30 static int ioapic_probe(struct pci_dev *dev, const struct pci_device_id *ent)
  31 {
  32         acpi_handle handle;
  33         acpi_status status;
  34         unsigned long long gsb;
  35         struct ioapic *ioapic;
  36         int ret;
  37         char *type;
  38         struct resource *res;
  39
  40         handle = DEVICE_ACPI_HANDLE(&dev->dev);
  41         if (!handle)
  42                 return -EINVAL;
  43
  44         status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsb);
  45         if (ACPI_FAILURE(status))
  46                 return -EINVAL;
  47
  48         /*
  49          * The previous code in acpiphp evaluated _MAT if _GSB failed, but
  50          * ACPI spec 4.0 sec 6.2.2 requires _GSB for hot-pluggable I/O APICs.
  51          */
  52
  53         ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
  54         if (!ioapic)
  55                 return -ENOMEM;
  56
  57         ioapic->handle = handle;
  58         ioapic->gsi_base = (u32) gsb;
  59
  60         if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
  61                 type = "IOAPIC";
  62         else
  63                 type = "IOxAPIC";
  64
  65         ret = pci_enable_device(dev);
  66         if (ret < 0)
  67                 goto exit_free;
  68
  69         pci_set_master(dev);
  70
  71         if (pci_request_region(dev, 0, type))
  72                 goto exit_disable;
  73
  74         res = &dev->resource[0];
  75         if (acpi_register_ioapic(ioapic->handle, res->start, ioapic->gsi_base))
  76                 goto exit_release;
  77
  78         pci_set_drvdata(dev, ioapic);
  79         dev_info(&dev->dev, "%s at %pR, GSI %u\n", type, res, ioapic->gsi_base);
  80         return 0;
  81
  82 exit_release:
  83         pci_release_region(dev, 0);
  84 exit_disable:
  85         pci_disable_device(dev);
  86 exit_free:
  87         kfree(ioapic);
  88         return -ENODEV;
  89 }
  90
  91 static void ioapic_remove(struct pci_dev *dev)
  92 {
  93         struct ioapic *ioapic = pci_get_drvdata(dev);
  94
  95         acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base);
  96         pci_release_region(dev, 0);
  97         pci_disable_device(dev);
  98         kfree(ioapic);
  99 }
 100
 101
 102 static DEFINE_PCI_DEVICE_TABLE(ioapic_devices) = {
 103         { PCI_DEVICE_CLASS(PCI_CLASS_SYSTEM_PIC_IOAPIC, ~0) },
 104         { PCI_DEVICE_CLASS(PCI_CLASS_SYSTEM_PIC_IOXAPIC, ~0) },
 105         { }
 106 };
 107 MODULE_DEVICE_TABLE(pci, ioapic_devices);
 108
 109 static struct pci_driver ioapic_driver = {
 110         .name           = "ioapic",
 111         .id_table       = ioapic_devices,
 112         .probe          = ioapic_probe,
 113         .remove         = ioapic_remove,
 114 };
 115
 116 static int __init ioapic_init(void)
 117 {
 118         return pci_register_driver(&ioapic_driver);
 119 }
 120
 121 static void __exit ioapic_exit(void)
 122 {
 123         pci_unregister_driver(&ioapic_driver);
 124 }
 125
 126 module_init(ioapic_init);
 127 module_exit(ioapic_exit);
 128
 129 MODULE_LICENSE("GPL");