drivers/acpi/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  * Copyright (C) 2014 Intel Corporation
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * Based on original drivers/pci/ioapic.c
  14  *      Yinghai Lu <yinghai@kernel.org>
  15  *      Jiang Liu <jiang.liu@intel.com>
  16  */
  17
  18 /*
  19  * This driver manages I/O APICs added by hotplug after boot.
  20  * We try to claim all I/O APIC devices, but those present at boot were
  21  * registered when we parsed the ACPI MADT.
  22  */
  23
  24 #define pr_fmt(fmt) "ACPI : IOAPIC: " fmt
  25
  26 #include <linux/slab.h>
  27 #include <linux/acpi.h>
  28 #include <linux/pci.h>
  29 #include <acpi/acpi.h>
  30
  31 struct acpi_pci_ioapic {
  32         acpi_handle     root_handle;
  33         acpi_handle     handle;
  34         u32             gsi_base;
  35         struct resource res;
  36         struct pci_dev  *pdev;
  37         struct list_head list;
  38 };
  39
  40 static LIST_HEAD(ioapic_list);
  41 static DEFINE_MUTEX(ioapic_list_lock);
  42
  43 static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
  44 {
  45         struct resource *res = data;
  46         struct resource_win win;
  47
  48         res->flags = 0;
  49         if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM) == 0)
  50                 return AE_OK;
  51
  52         if (!acpi_dev_resource_memory(acpi_res, res)) {
  53                 if (acpi_dev_resource_address_space(acpi_res, &win) ||
  54                     acpi_dev_resource_ext_address_space(acpi_res, &win))
  55                         *res = win.res;
  56         }
  57         if ((res->flags & IORESOURCE_PREFETCH) ||
  58             (res->flags & IORESOURCE_DISABLED))
  59                 res->flags = 0;
  60
  61         return AE_CTRL_TERMINATE;
  62 }
  63
  64 static bool acpi_is_ioapic(acpi_handle handle, char **type)
  65 {
  66         acpi_status status;
  67         struct acpi_device_info *info;
  68         char *hid = NULL;
  69         bool match = false;
  70
  71         if (!acpi_has_method(handle, "_GSB"))
  72                 return false;
  73
  74         status = acpi_get_object_info(handle, &info);
  75         if (ACPI_SUCCESS(status)) {
  76                 if (info->valid & ACPI_VALID_HID)
  77                         hid = info->hardware_id.string;
  78                 if (hid) {
  79                         if (strcmp(hid, "ACPI0009") == 0) {
  80                                 *type = "IOxAPIC";
  81                                 match = true;
  82                         } else if (strcmp(hid, "ACPI000A") == 0) {
  83                                 *type = "IOAPIC";
  84                                 match = true;
  85                         }
  86                 }
  87                 kfree(info);
  88         }
  89
  90         return match;
  91 }
  92
  93 static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
  94                                      void *context, void **rv)
  95 {
  96         acpi_status status;
  97         unsigned long long gsi_base;
  98         struct acpi_pci_ioapic *ioapic;
  99         struct pci_dev *dev = NULL;
 100         struct resource *res = NULL;
 101         char *type = NULL;
 102
 103         if (!acpi_is_ioapic(handle, &type))
 104                 return AE_OK;
 105
 106         mutex_lock(&ioapic_list_lock);
 107         list_for_each_entry(ioapic, &ioapic_list, list)
 108                 if (ioapic->handle == handle) {
 109                         mutex_unlock(&ioapic_list_lock);
 110                         return AE_OK;
 111                 }
 112
 113         status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsi_base);
 114         if (ACPI_FAILURE(status)) {
 115                 acpi_handle_warn(handle, "failed to evaluate _GSB method\n");
 116                 goto exit;
 117         }
 118
 119         ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
 120         if (!ioapic) {
 121                 pr_err("cannot allocate memory for new IOAPIC\n");
 122                 goto exit;
 123         } else {
 124                 ioapic->root_handle = (acpi_handle)context;
 125                 ioapic->handle = handle;
 126                 ioapic->gsi_base = (u32)gsi_base;
 127                 INIT_LIST_HEAD(&ioapic->list);
 128         }
 129
 130         if (acpi_ioapic_registered(handle, (u32)gsi_base))
 131                 goto done;
 132
 133         dev = acpi_get_pci_dev(handle);
 134         if (dev && pci_resource_len(dev, 0)) {
 135                 if (pci_enable_device(dev) < 0)
 136                         goto exit_put;
 137                 pci_set_master(dev);
 138                 if (pci_request_region(dev, 0, type))
 139                         goto exit_disable;
 140                 res = &dev->resource[0];
 141                 ioapic->pdev = dev;
 142         } else {
 143                 pci_dev_put(dev);
 144                 dev = NULL;
 145
 146                 res = &ioapic->res;
 147                 acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, res);
 148                 if (res->flags == 0) {
 149                         acpi_handle_warn(handle, "failed to get resource\n");
 150                         goto exit_free;
 151                 } else if (request_resource(&iomem_resource, res)) {
 152                         acpi_handle_warn(handle, "failed to insert resource\n");
 153                         goto exit_free;
 154                 }
 155         }
 156
 157         if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
 158                 acpi_handle_warn(handle, "failed to register IOAPIC\n");
 159                 goto exit_release;
 160         }
 161 done:
 162         list_add(&ioapic->list, &ioapic_list);
 163         mutex_unlock(&ioapic_list_lock);
 164
 165         if (dev)
 166                 dev_info(&dev->dev, "%s at %pR, GSI %u\n",
 167                          type, res, (u32)gsi_base);
 168         else
 169                 acpi_handle_info(handle, "%s at %pR, GSI %u\n",
 170                                  type, res, (u32)gsi_base);
 171
 172         return AE_OK;
 173
 174 exit_release:
 175         if (dev)
 176                 pci_release_region(dev, 0);
 177         else
 178                 release_resource(res);
 179 exit_disable:
 180         if (dev)
 181                 pci_disable_device(dev);
 182 exit_put:
 183         pci_dev_put(dev);
 184 exit_free:
 185         kfree(ioapic);
 186 exit:
 187         mutex_unlock(&ioapic_list_lock);
 188         *(acpi_status *)rv = AE_ERROR;
 189         return AE_OK;
 190 }
 191
 192 int acpi_ioapic_add(struct acpi_pci_root *root)
 193 {
 194         acpi_status status, retval = AE_OK;
 195
 196         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle,
 197                                      UINT_MAX, handle_ioapic_add, NULL,
 198                                      root->device->handle, (void **)&retval);
 199
 200         return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
 201 }
 202
 203 int acpi_ioapic_remove(struct acpi_pci_root *root)
 204 {
 205         int retval = 0;
 206         struct acpi_pci_ioapic *ioapic, *tmp;
 207
 208         mutex_lock(&ioapic_list_lock);
 209         list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
 210                 if (root->device->handle != ioapic->root_handle)
 211                         continue;
 212
 213                 if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
 214                         retval = -EBUSY;
 215
 216                 if (ioapic->pdev) {
 217                         pci_release_region(ioapic->pdev, 0);
 218                         pci_disable_device(ioapic->pdev);
 219                         pci_dev_put(ioapic->pdev);
 220                 } else if (ioapic->res.flags && ioapic->res.parent) {
 221                         release_resource(&ioapic->res);
 222                 }
 223                 list_del(&ioapic->list);
 224                 kfree(ioapic);
 225         }
 226         mutex_unlock(&ioapic_list_lock);
 227
 228         return retval;
 229 }