linux/drivers/acpi/ioapic.c
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   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
  31struct 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
  40static LIST_HEAD(ioapic_list);
  41static DEFINE_MUTEX(ioapic_list_lock);
  42
  43static 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))
  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
  64static 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
  93static 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, *pci_res = NULL, *crs_res;
 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                pci_res = &dev->resource[0];
 141                ioapic->pdev = dev;
 142        } else {
 143                pci_dev_put(dev);
 144                dev = NULL;
 145        }
 146
 147        crs_res = &ioapic->res;
 148        acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
 149        crs_res->name = type;
 150        crs_res->flags |= IORESOURCE_BUSY;
 151        if (crs_res->flags == 0) {
 152                acpi_handle_warn(handle, "failed to get resource\n");
 153                goto exit_release;
 154        } else if (insert_resource(&iomem_resource, crs_res)) {
 155                acpi_handle_warn(handle, "failed to insert resource\n");
 156                goto exit_release;
 157        }
 158
 159        /* try pci resource first, then "_CRS" resource */
 160        res = pci_res;
 161        if (!res || !res->flags)
 162                res = crs_res;
 163
 164        if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
 165                acpi_handle_warn(handle, "failed to register IOAPIC\n");
 166                goto exit_release;
 167        }
 168done:
 169        list_add(&ioapic->list, &ioapic_list);
 170        mutex_unlock(&ioapic_list_lock);
 171
 172        if (dev)
 173                dev_info(&dev->dev, "%s at %pR, GSI %u\n",
 174                         type, res, (u32)gsi_base);
 175        else
 176                acpi_handle_info(handle, "%s at %pR, GSI %u\n",
 177                                 type, res, (u32)gsi_base);
 178
 179        return AE_OK;
 180
 181exit_release:
 182        if (dev)
 183                pci_release_region(dev, 0);
 184        if (ioapic->res.flags && ioapic->res.parent)
 185                release_resource(&ioapic->res);
 186exit_disable:
 187        if (dev)
 188                pci_disable_device(dev);
 189exit_put:
 190        pci_dev_put(dev);
 191        kfree(ioapic);
 192exit:
 193        mutex_unlock(&ioapic_list_lock);
 194        *(acpi_status *)rv = AE_ERROR;
 195        return AE_OK;
 196}
 197
 198int acpi_ioapic_add(acpi_handle root_handle)
 199{
 200        acpi_status status, retval = AE_OK;
 201
 202        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
 203                                     UINT_MAX, handle_ioapic_add, NULL,
 204                                     root_handle, (void **)&retval);
 205
 206        return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
 207}
 208
 209int acpi_ioapic_remove(struct acpi_pci_root *root)
 210{
 211        int retval = 0;
 212        struct acpi_pci_ioapic *ioapic, *tmp;
 213
 214        mutex_lock(&ioapic_list_lock);
 215        list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
 216                if (root->device->handle != ioapic->root_handle)
 217                        continue;
 218
 219                if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
 220                        retval = -EBUSY;
 221
 222                if (ioapic->pdev) {
 223                        pci_release_region(ioapic->pdev, 0);
 224                        pci_disable_device(ioapic->pdev);
 225                        pci_dev_put(ioapic->pdev);
 226                }
 227                if (ioapic->res.flags && ioapic->res.parent)
 228                        release_resource(&ioapic->res);
 229                list_del(&ioapic->list);
 230                kfree(ioapic);
 231        }
 232        mutex_unlock(&ioapic_list_lock);
 233
 234        return retval;
 235}
 236