linux/drivers/acpi/pci_slot.c
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   1/*
   2 *  pci_slot.c - ACPI PCI Slot Driver
   3 *
   4 *  The code here is heavily leveraged from the acpiphp module.
   5 *  Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance.
   6 *  Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code
   7 *  review and fixes.
   8 *
   9 *  Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P.
  10 *      Alex Chiang <achiang@hp.com>
  11 *
  12 *  This program is free software; you can redistribute it and/or modify it
  13 *  under the terms and conditions of the GNU General Public License,
  14 *  version 2, as published by the Free Software Foundation.
  15 *
  16 *  This program is distributed in the hope that it will be useful, but
  17 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  18 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 *  General Public License for more details.
  20 *
  21 *  You should have received a copy of the GNU General Public License along
  22 *  with this program; if not, write to the Free Software Foundation, Inc.,
  23 *  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  24 */
  25
  26#include <linux/kernel.h>
  27#include <linux/module.h>
  28#include <linux/init.h>
  29#include <linux/slab.h>
  30#include <linux/types.h>
  31#include <linux/pci.h>
  32#include <linux/acpi.h>
  33#include <acpi/acpi_bus.h>
  34#include <acpi/acpi_drivers.h>
  35#include <linux/dmi.h>
  36
  37static bool debug;
  38static int check_sta_before_sun;
  39
  40#define DRIVER_VERSION  "0.1"
  41#define DRIVER_AUTHOR   "Alex Chiang <achiang@hp.com>"
  42#define DRIVER_DESC     "ACPI PCI Slot Detection Driver"
  43MODULE_AUTHOR(DRIVER_AUTHOR);
  44MODULE_DESCRIPTION(DRIVER_DESC);
  45MODULE_LICENSE("GPL");
  46MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  47module_param(debug, bool, 0644);
  48
  49#define _COMPONENT              ACPI_PCI_COMPONENT
  50ACPI_MODULE_NAME("pci_slot");
  51
  52#define MY_NAME "pci_slot"
  53#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
  54#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
  55#define dbg(format, arg...)                                     \
  56        do {                                                    \
  57                if (debug)                                      \
  58                        printk(KERN_DEBUG "%s: " format,        \
  59                                MY_NAME , ## arg);              \
  60        } while (0)
  61
  62#define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  63
  64struct acpi_pci_slot {
  65        acpi_handle root_handle;        /* handle of the root bridge */
  66        struct pci_slot *pci_slot;      /* corresponding pci_slot */
  67        struct list_head list;          /* node in the list of slots */
  68};
  69
  70static int acpi_pci_slot_add(struct acpi_pci_root *root);
  71static void acpi_pci_slot_remove(struct acpi_pci_root *root);
  72
  73static LIST_HEAD(slot_list);
  74static DEFINE_MUTEX(slot_list_lock);
  75static struct acpi_pci_driver acpi_pci_slot_driver = {
  76        .add = acpi_pci_slot_add,
  77        .remove = acpi_pci_slot_remove,
  78};
  79
  80static int
  81check_slot(acpi_handle handle, unsigned long long *sun)
  82{
  83        int device = -1;
  84        unsigned long long adr, sta;
  85        acpi_status status;
  86        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  87
  88        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
  89        dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
  90
  91        if (check_sta_before_sun) {
  92                /* If SxFy doesn't have _STA, we just assume it's there */
  93                status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  94                if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
  95                        goto out;
  96        }
  97
  98        status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
  99        if (ACPI_FAILURE(status)) {
 100                dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
 101                goto out;
 102        }
 103
 104        /* No _SUN == not a slot == bail */
 105        status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
 106        if (ACPI_FAILURE(status)) {
 107                dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
 108                goto out;
 109        }
 110
 111        device = (adr >> 16) & 0xffff;
 112out:
 113        kfree(buffer.pointer);
 114        return device;
 115}
 116
 117struct callback_args {
 118        acpi_walk_callback      user_function;  /* only for walk_p2p_bridge */
 119        struct pci_bus          *pci_bus;
 120        acpi_handle             root_handle;
 121};
 122
 123/*
 124 * register_slot
 125 *
 126 * Called once for each SxFy object in the namespace. Don't worry about
 127 * calling pci_create_slot multiple times for the same pci_bus:device,
 128 * since each subsequent call simply bumps the refcount on the pci_slot.
 129 *
 130 * The number of calls to pci_destroy_slot from unregister_slot is
 131 * symmetrical.
 132 */
 133static acpi_status
 134register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 135{
 136        int device;
 137        unsigned long long sun;
 138        char name[SLOT_NAME_SIZE];
 139        struct acpi_pci_slot *slot;
 140        struct pci_slot *pci_slot;
 141        struct callback_args *parent_context = context;
 142        struct pci_bus *pci_bus = parent_context->pci_bus;
 143
 144        device = check_slot(handle, &sun);
 145        if (device < 0)
 146                return AE_OK;
 147
 148        slot = kmalloc(sizeof(*slot), GFP_KERNEL);
 149        if (!slot) {
 150                err("%s: cannot allocate memory\n", __func__);
 151                return AE_OK;
 152        }
 153
 154        snprintf(name, sizeof(name), "%llu", sun);
 155        pci_slot = pci_create_slot(pci_bus, device, name, NULL);
 156        if (IS_ERR(pci_slot)) {
 157                err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
 158                kfree(slot);
 159                return AE_OK;
 160        }
 161
 162        slot->root_handle = parent_context->root_handle;
 163        slot->pci_slot = pci_slot;
 164        INIT_LIST_HEAD(&slot->list);
 165        mutex_lock(&slot_list_lock);
 166        list_add(&slot->list, &slot_list);
 167        mutex_unlock(&slot_list_lock);
 168
 169        get_device(&pci_bus->dev);
 170
 171        dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
 172                pci_slot, pci_bus->number, device, name);
 173
 174        return AE_OK;
 175}
 176
 177/*
 178 * walk_p2p_bridge - discover and walk p2p bridges
 179 * @handle: points to an acpi_pci_root
 180 * @context: p2p_bridge_context pointer
 181 *
 182 * Note that when we call ourselves recursively, we pass a different
 183 * value of pci_bus in the child_context.
 184 */
 185static acpi_status
 186walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
 187{
 188        int device, function;
 189        unsigned long long adr;
 190        acpi_status status;
 191        acpi_handle dummy_handle;
 192        acpi_walk_callback user_function;
 193
 194        struct pci_dev *dev;
 195        struct pci_bus *pci_bus;
 196        struct callback_args child_context;
 197        struct callback_args *parent_context = context;
 198
 199        pci_bus = parent_context->pci_bus;
 200        user_function = parent_context->user_function;
 201
 202        status = acpi_get_handle(handle, "_ADR", &dummy_handle);
 203        if (ACPI_FAILURE(status))
 204                return AE_OK;
 205
 206        status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 207        if (ACPI_FAILURE(status))
 208                return AE_OK;
 209
 210        device = (adr >> 16) & 0xffff;
 211        function = adr & 0xffff;
 212
 213        dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
 214        if (!dev || !dev->subordinate)
 215                goto out;
 216
 217        child_context.pci_bus = dev->subordinate;
 218        child_context.user_function = user_function;
 219        child_context.root_handle = parent_context->root_handle;
 220
 221        dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
 222        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 223                                     user_function, NULL, &child_context, NULL);
 224        if (ACPI_FAILURE(status))
 225                goto out;
 226
 227        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 228                                     walk_p2p_bridge, NULL, &child_context, NULL);
 229out:
 230        pci_dev_put(dev);
 231        return AE_OK;
 232}
 233
 234/*
 235 * walk_root_bridge - generic root bridge walker
 236 * @root: poiner of an acpi_pci_root
 237 * @user_function: user callback for slot objects
 238 *
 239 * Call user_function for all objects underneath this root bridge.
 240 * Walk p2p bridges underneath us and call user_function on those too.
 241 */
 242static int
 243walk_root_bridge(struct acpi_pci_root *root, acpi_walk_callback user_function)
 244{
 245        acpi_status status;
 246        acpi_handle handle = root->device->handle;
 247        struct pci_bus *pci_bus = root->bus;
 248        struct callback_args context;
 249
 250        context.pci_bus = pci_bus;
 251        context.user_function = user_function;
 252        context.root_handle = handle;
 253
 254        dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
 255        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 256                                     user_function, NULL, &context, NULL);
 257        if (ACPI_FAILURE(status))
 258                return status;
 259
 260        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 261                                     walk_p2p_bridge, NULL, &context, NULL);
 262        if (ACPI_FAILURE(status))
 263                err("%s: walk_p2p_bridge failure - %d\n", __func__, status);
 264
 265        return status;
 266}
 267
 268/*
 269 * acpi_pci_slot_add
 270 * @handle: points to an acpi_pci_root
 271 */
 272static int
 273acpi_pci_slot_add(struct acpi_pci_root *root)
 274{
 275        acpi_status status;
 276
 277        status = walk_root_bridge(root, register_slot);
 278        if (ACPI_FAILURE(status))
 279                err("%s: register_slot failure - %d\n", __func__, status);
 280
 281        return status;
 282}
 283
 284/*
 285 * acpi_pci_slot_remove
 286 * @handle: points to an acpi_pci_root
 287 */
 288static void
 289acpi_pci_slot_remove(struct acpi_pci_root *root)
 290{
 291        struct acpi_pci_slot *slot, *tmp;
 292        struct pci_bus *pbus;
 293        acpi_handle handle = root->device->handle;
 294
 295        mutex_lock(&slot_list_lock);
 296        list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 297                if (slot->root_handle == handle) {
 298                        list_del(&slot->list);
 299                        pbus = slot->pci_slot->bus;
 300                        pci_destroy_slot(slot->pci_slot);
 301                        put_device(&pbus->dev);
 302                        kfree(slot);
 303                }
 304        }
 305        mutex_unlock(&slot_list_lock);
 306}
 307
 308static int do_sta_before_sun(const struct dmi_system_id *d)
 309{
 310        info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
 311        check_sta_before_sun = 1;
 312        return 0;
 313}
 314
 315static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
 316        /*
 317         * Fujitsu Primequest machines will return 1023 to indicate an
 318         * error if the _SUN method is evaluated on SxFy objects that
 319         * are not present (as indicated by _STA), so for those machines,
 320         * we want to check _STA before evaluating _SUN.
 321         */
 322        {
 323         .callback = do_sta_before_sun,
 324         .ident = "Fujitsu PRIMEQUEST",
 325         .matches = {
 326                DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 327                DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 328                },
 329        },
 330        {}
 331};
 332
 333static int __init
 334acpi_pci_slot_init(void)
 335{
 336        dmi_check_system(acpi_pci_slot_dmi_table);
 337        acpi_pci_register_driver(&acpi_pci_slot_driver);
 338        return 0;
 339}
 340
 341static void __exit
 342acpi_pci_slot_exit(void)
 343{
 344        acpi_pci_unregister_driver(&acpi_pci_slot_driver);
 345}
 346
 347module_init(acpi_pci_slot_init);
 348module_exit(acpi_pci_slot_exit);
 349
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