linux/drivers/acpi/ioapic.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * IOAPIC/IOxAPIC/IOSAPIC driver
   4 *
   5 * Copyright (C) 2009 Fujitsu Limited.
   6 * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
   7 *
   8 * Copyright (C) 2014 Intel Corporation
   9 *
  10 * Based on original drivers/pci/ioapic.c
  11 *      Yinghai Lu <yinghai@kernel.org>
  12 *      Jiang Liu <jiang.liu@intel.com>
  13 */
  14
  15/*
  16 * This driver manages I/O APICs added by hotplug after boot.
  17 * We try to claim all I/O APIC devices, but those present at boot were
  18 * registered when we parsed the ACPI MADT.
  19 */
  20
  21#define pr_fmt(fmt) "ACPI: IOAPIC: " fmt
  22
  23#include <linux/slab.h>
  24#include <linux/acpi.h>
  25#include <linux/pci.h>
  26#include <acpi/acpi.h>
  27
  28struct acpi_pci_ioapic {
  29        acpi_handle     root_handle;
  30        acpi_handle     handle;
  31        u32             gsi_base;
  32        struct resource res;
  33        struct pci_dev  *pdev;
  34        struct list_head list;
  35};
  36
  37static LIST_HEAD(ioapic_list);
  38static DEFINE_MUTEX(ioapic_list_lock);
  39
  40static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
  41{
  42        struct resource *res = data;
  43        struct resource_win win;
  44
  45        /*
  46         * We might assign this to 'res' later, make sure all pointers are
  47         * cleared before the resource is added to the global list
  48         */
  49        memset(&win, 0, sizeof(win));
  50
  51        res->flags = 0;
  52        if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
  53                return AE_OK;
  54
  55        if (!acpi_dev_resource_memory(acpi_res, res)) {
  56                if (acpi_dev_resource_address_space(acpi_res, &win) ||
  57                    acpi_dev_resource_ext_address_space(acpi_res, &win))
  58                        *res = win.res;
  59        }
  60        if ((res->flags & IORESOURCE_PREFETCH) ||
  61            (res->flags & IORESOURCE_DISABLED))
  62                res->flags = 0;
  63
  64        return AE_CTRL_TERMINATE;
  65}
  66
  67static bool acpi_is_ioapic(acpi_handle handle, char **type)
  68{
  69        acpi_status status;
  70        struct acpi_device_info *info;
  71        char *hid = NULL;
  72        bool match = false;
  73
  74        if (!acpi_has_method(handle, "_GSB"))
  75                return false;
  76
  77        status = acpi_get_object_info(handle, &info);
  78        if (ACPI_SUCCESS(status)) {
  79                if (info->valid & ACPI_VALID_HID)
  80                        hid = info->hardware_id.string;
  81                if (hid) {
  82                        if (strcmp(hid, "ACPI0009") == 0) {
  83                                *type = "IOxAPIC";
  84                                match = true;
  85                        } else if (strcmp(hid, "ACPI000A") == 0) {
  86                                *type = "IOAPIC";
  87                                match = true;
  88                        }
  89                }
  90                kfree(info);
  91        }
  92
  93        return match;
  94}
  95
  96static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
  97                                     void *context, void **rv)
  98{
  99        acpi_status status;
 100        unsigned long long gsi_base;
 101        struct acpi_pci_ioapic *ioapic;
 102        struct pci_dev *dev = NULL;
 103        struct resource *res = NULL, *pci_res = NULL, *crs_res;
 104        char *type = NULL;
 105
 106        if (!acpi_is_ioapic(handle, &type))
 107                return AE_OK;
 108
 109        mutex_lock(&ioapic_list_lock);
 110        list_for_each_entry(ioapic, &ioapic_list, list)
 111                if (ioapic->handle == handle) {
 112                        mutex_unlock(&ioapic_list_lock);
 113                        return AE_OK;
 114                }
 115
 116        status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsi_base);
 117        if (ACPI_FAILURE(status)) {
 118                acpi_handle_warn(handle, "failed to evaluate _GSB method\n");
 119                goto exit;
 120        }
 121
 122        ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
 123        if (!ioapic) {
 124                pr_err("cannot allocate memory for new IOAPIC\n");
 125                goto exit;
 126        } else {
 127                ioapic->root_handle = (acpi_handle)context;
 128                ioapic->handle = handle;
 129                ioapic->gsi_base = (u32)gsi_base;
 130                INIT_LIST_HEAD(&ioapic->list);
 131        }
 132
 133        if (acpi_ioapic_registered(handle, (u32)gsi_base))
 134                goto done;
 135
 136        dev = acpi_get_pci_dev(handle);
 137        if (dev && pci_resource_len(dev, 0)) {
 138                if (pci_enable_device(dev) < 0)
 139                        goto exit_put;
 140                pci_set_master(dev);
 141                if (pci_request_region(dev, 0, type))
 142                        goto exit_disable;
 143                pci_res = &dev->resource[0];
 144                ioapic->pdev = dev;
 145        } else {
 146                pci_dev_put(dev);
 147                dev = NULL;
 148        }
 149
 150        crs_res = &ioapic->res;
 151        acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
 152        crs_res->name = type;
 153        crs_res->flags |= IORESOURCE_BUSY;
 154        if (crs_res->flags == 0) {
 155                acpi_handle_warn(handle, "failed to get resource\n");
 156                goto exit_release;
 157        } else if (insert_resource(&iomem_resource, crs_res)) {
 158                acpi_handle_warn(handle, "failed to insert resource\n");
 159                goto exit_release;
 160        }
 161
 162        /* try pci resource first, then "_CRS" resource */
 163        res = pci_res;
 164        if (!res || !res->flags)
 165                res = crs_res;
 166
 167        if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
 168                acpi_handle_warn(handle, "failed to register IOAPIC\n");
 169                goto exit_release;
 170        }
 171done:
 172        list_add(&ioapic->list, &ioapic_list);
 173        mutex_unlock(&ioapic_list_lock);
 174
 175        if (dev)
 176                dev_info(&dev->dev, "%s at %pR, GSI %u\n",
 177                         type, res, (u32)gsi_base);
 178        else
 179                acpi_handle_info(handle, "%s at %pR, GSI %u\n",
 180                                 type, res, (u32)gsi_base);
 181
 182        return AE_OK;
 183
 184exit_release:
 185        if (dev)
 186                pci_release_region(dev, 0);
 187        if (ioapic->res.flags && ioapic->res.parent)
 188                release_resource(&ioapic->res);
 189exit_disable:
 190        if (dev)
 191                pci_disable_device(dev);
 192exit_put:
 193        pci_dev_put(dev);
 194        kfree(ioapic);
 195exit:
 196        mutex_unlock(&ioapic_list_lock);
 197        *(acpi_status *)rv = AE_ERROR;
 198        return AE_OK;
 199}
 200
 201int acpi_ioapic_add(acpi_handle root_handle)
 202{
 203        acpi_status status, retval = AE_OK;
 204
 205        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
 206                                     UINT_MAX, handle_ioapic_add, NULL,
 207                                     root_handle, (void **)&retval);
 208
 209        return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
 210}
 211
 212void pci_ioapic_remove(struct acpi_pci_root *root)
 213{
 214        struct acpi_pci_ioapic *ioapic, *tmp;
 215
 216        mutex_lock(&ioapic_list_lock);
 217        list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
 218                if (root->device->handle != ioapic->root_handle)
 219                        continue;
 220                if (ioapic->pdev) {
 221                        pci_release_region(ioapic->pdev, 0);
 222                        pci_disable_device(ioapic->pdev);
 223                        pci_dev_put(ioapic->pdev);
 224                }
 225        }
 226        mutex_unlock(&ioapic_list_lock);
 227}
 228
 229int acpi_ioapic_remove(struct acpi_pci_root *root)
 230{
 231        int retval = 0;
 232        struct acpi_pci_ioapic *ioapic, *tmp;
 233
 234        mutex_lock(&ioapic_list_lock);
 235        list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
 236                if (root->device->handle != ioapic->root_handle)
 237                        continue;
 238                if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
 239                        retval = -EBUSY;
 240                if (ioapic->res.flags && ioapic->res.parent)
 241                        release_resource(&ioapic->res);
 242                list_del(&ioapic->list);
 243                kfree(ioapic);
 244        }
 245        mutex_unlock(&ioapic_list_lock);
 246
 247        return retval;
 248}
 249