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/acpi.h>
  21 #include <acpi/acpi_bus.h>
  22
  23 struct ioapic {
  24         acpi_handle     handle;
  25         u32             gsi_base;
  26 };
  27
  28 static int ioapic_probe(struct pci_dev *dev, const struct pci_device_id *ent)
  29 {
  30         acpi_handle handle;
  31         acpi_status status;
  32         unsigned long long gsb;
  33         struct ioapic *ioapic;
  34         int ret;
  35         char *type;
  36         struct resource *res;
  37
  38         handle = DEVICE_ACPI_HANDLE(&dev->dev);
  39         if (!handle)
  40                 return -EINVAL;
  41
  42         status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsb);
  43         if (ACPI_FAILURE(status))
  44                 return -EINVAL;
  45
  46         /*
  47          * The previous code in acpiphp evaluated _MAT if _GSB failed, but
  48          * ACPI spec 4.0 sec 6.2.2 requires _GSB for hot-pluggable I/O APICs.
  49          */
  50
  51         ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
  52         if (!ioapic)
  53                 return -ENOMEM;
  54
  55         ioapic->handle = handle;
  56         ioapic->gsi_base = (u32) gsb;
  57
  58         if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
  59                 type = "IOAPIC";
  60         else
  61                 type = "IOxAPIC";
  62
  63         ret = pci_enable_device(dev);
  64         if (ret < 0)
  65                 goto exit_free;
  66
  67         pci_set_master(dev);
  68
  69         if (pci_request_region(dev, 0, type))
  70                 goto exit_disable;
  71
  72         res = &dev->resource[0];
  73         if (acpi_register_ioapic(ioapic->handle, res->start, ioapic->gsi_base))
  74                 goto exit_release;
  75
  76         pci_set_drvdata(dev, ioapic);
  77         dev_info(&dev->dev, "%s at %pR, GSI %u\n", type, res, ioapic->gsi_base);
  78         return 0;
  79
  80 exit_release:
  81         pci_release_region(dev, 0);
  82 exit_disable:
  83         pci_disable_device(dev);
  84 exit_free:
  85         kfree(ioapic);
  86         return -ENODEV;
  87 }
  88
  89 static void ioapic_remove(struct pci_dev *dev)
  90 {
  91         struct ioapic *ioapic = pci_get_drvdata(dev);
  92
  93         acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base);
  94         pci_release_region(dev, 0);
  95         pci_disable_device(dev);
  96         kfree(ioapic);
  97 }
  98
  99
 100 static struct pci_device_id ioapic_devices[] = {
 101         { PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
 102           PCI_CLASS_SYSTEM_PIC_IOAPIC << 8, 0xffff00, },
 103         { PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
 104           PCI_CLASS_SYSTEM_PIC_IOXAPIC << 8, 0xffff00, },
 105         { }
 106 };
 107
 108 static struct pci_driver ioapic_driver = {
 109         .name           = "ioapic",
 110         .id_table       = ioapic_devices,
 111         .probe          = ioapic_probe,
 112         .remove         = __devexit_p(ioapic_remove),
 113 };
 114
 115 static int __init ioapic_init(void)
 116 {
 117         return pci_register_driver(&ioapic_driver);
 118 }
 119
 120 static void __exit ioapic_exit(void)
 121 {
 122         pci_unregister_driver(&ioapic_driver);
 123 }
 124
 125 module_init(ioapic_init);
 126 module_exit(ioapic_exit);