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...) pr_err("%s: " format , MY_NAME , ## arg)
  54#define info(format, arg...) pr_info("%s: " format , MY_NAME , ## arg)
  55#define dbg(format, arg...)                                     \
  56        do {                                                    \
  57                if (debug)                                      \
  58                        pr_debug("%s: " format, MY_NAME , ## arg); \
  59        } while (0)
  60
  61#define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  62
  63struct acpi_pci_slot {
  64        acpi_handle root_handle;        /* handle of the root bridge */
  65        struct pci_slot *pci_slot;      /* corresponding pci_slot */
  66        struct list_head list;          /* node in the list of slots */
  67};
  68
  69static int acpi_pci_slot_add(struct acpi_pci_root *root);
  70static void acpi_pci_slot_remove(struct acpi_pci_root *root);
  71
  72static LIST_HEAD(slot_list);
  73static DEFINE_MUTEX(slot_list_lock);
  74static struct acpi_pci_driver acpi_pci_slot_driver = {
  75        .add = acpi_pci_slot_add,
  76        .remove = acpi_pci_slot_remove,
  77};
  78
  79static int
  80check_slot(acpi_handle handle, unsigned long long *sun)
  81{
  82        int device = -1;
  83        unsigned long long adr, sta;
  84        acpi_status status;
  85        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  86
  87        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
  88        dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
  89
  90        if (check_sta_before_sun) {
  91                /* If SxFy doesn't have _STA, we just assume it's there */
  92                status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  93                if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
  94                        goto out;
  95        }
  96
  97        status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
  98        if (ACPI_FAILURE(status)) {
  99                dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
 100                goto out;
 101        }
 102
 103        /* No _SUN == not a slot == bail */
 104        status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
 105        if (ACPI_FAILURE(status)) {
 106                dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
 107                goto out;
 108        }
 109
 110        device = (adr >> 16) & 0xffff;
 111out:
 112        kfree(buffer.pointer);
 113        return device;
 114}
 115
 116struct callback_args {
 117        acpi_walk_callback      user_function;  /* only for walk_p2p_bridge */
 118        struct pci_bus          *pci_bus;
 119        acpi_handle             root_handle;
 120};
 121
 122/*
 123 * register_slot
 124 *
 125 * Called once for each SxFy object in the namespace. Don't worry about
 126 * calling pci_create_slot multiple times for the same pci_bus:device,
 127 * since each subsequent call simply bumps the refcount on the pci_slot.
 128 *
 129 * The number of calls to pci_destroy_slot from unregister_slot is
 130 * symmetrical.
 131 */
 132static acpi_status
 133register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 134{
 135        int device;
 136        unsigned long long sun;
 137        char name[SLOT_NAME_SIZE];
 138        struct acpi_pci_slot *slot;
 139        struct pci_slot *pci_slot;
 140        struct callback_args *parent_context = context;
 141        struct pci_bus *pci_bus = parent_context->pci_bus;
 142
 143        device = check_slot(handle, &sun);
 144        if (device < 0)
 145                return AE_OK;
 146
 147        slot = kmalloc(sizeof(*slot), GFP_KERNEL);
 148        if (!slot) {
 149                err("%s: cannot allocate memory\n", __func__);
 150                return AE_OK;
 151        }
 152
 153        snprintf(name, sizeof(name), "%llu", sun);
 154        pci_slot = pci_create_slot(pci_bus, device, name, NULL);
 155        if (IS_ERR(pci_slot)) {
 156                err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
 157                kfree(slot);
 158                return AE_OK;
 159        }
 160
 161        slot->root_handle = parent_context->root_handle;
 162        slot->pci_slot = pci_slot;
 163        INIT_LIST_HEAD(&slot->list);
 164        mutex_lock(&slot_list_lock);
 165        list_add(&slot->list, &slot_list);
 166        mutex_unlock(&slot_list_lock);
 167
 168        get_device(&pci_bus->dev);
 169
 170        dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
 171                pci_slot, pci_bus->number, device, name);
 172
 173        return AE_OK;
 174}
 175
 176/*
 177 * walk_p2p_bridge - discover and walk p2p bridges
 178 * @handle: points to an acpi_pci_root
 179 * @context: p2p_bridge_context pointer
 180 *
 181 * Note that when we call ourselves recursively, we pass a different
 182 * value of pci_bus in the child_context.
 183 */
 184static acpi_status
 185walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
 186{
 187        int device, function;
 188        unsigned long long adr;
 189        acpi_status status;
 190        acpi_handle dummy_handle;
 191        acpi_walk_callback user_function;
 192
 193        struct pci_dev *dev;
 194        struct pci_bus *pci_bus;
 195        struct callback_args child_context;
 196        struct callback_args *parent_context = context;
 197
 198        pci_bus = parent_context->pci_bus;
 199        user_function = parent_context->user_function;
 200
 201        status = acpi_get_handle(handle, "_ADR", &dummy_handle);
 202        if (ACPI_FAILURE(status))
 203                return AE_OK;
 204
 205        status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 206        if (ACPI_FAILURE(status))
 207                return AE_OK;
 208
 209        device = (adr >> 16) & 0xffff;
 210        function = adr & 0xffff;
 211
 212        dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
 213        if (!dev || !dev->subordinate)
 214                goto out;
 215
 216        child_context.pci_bus = dev->subordinate;
 217        child_context.user_function = user_function;
 218        child_context.root_handle = parent_context->root_handle;
 219
 220        dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
 221        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 222                                     user_function, NULL, &child_context, NULL);
 223        if (ACPI_FAILURE(status))
 224                goto out;
 225
 226        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 227                                     walk_p2p_bridge, NULL, &child_context, NULL);
 228out:
 229        pci_dev_put(dev);
 230        return AE_OK;
 231}
 232
 233/*
 234 * walk_root_bridge - generic root bridge walker
 235 * @root: poiner of an acpi_pci_root
 236 * @user_function: user callback for slot objects
 237 *
 238 * Call user_function for all objects underneath this root bridge.
 239 * Walk p2p bridges underneath us and call user_function on those too.
 240 */
 241static int
 242walk_root_bridge(struct acpi_pci_root *root, acpi_walk_callback user_function)
 243{
 244        acpi_status status;
 245        acpi_handle handle = root->device->handle;
 246        struct pci_bus *pci_bus = root->bus;
 247        struct callback_args context;
 248
 249        context.pci_bus = pci_bus;
 250        context.user_function = user_function;
 251        context.root_handle = handle;
 252
 253        dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
 254        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 255                                     user_function, NULL, &context, NULL);
 256        if (ACPI_FAILURE(status))
 257                return status;
 258
 259        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 260                                     walk_p2p_bridge, NULL, &context, NULL);
 261        if (ACPI_FAILURE(status))
 262                err("%s: walk_p2p_bridge failure - %d\n", __func__, status);
 263
 264        return status;
 265}
 266
 267/*
 268 * acpi_pci_slot_add
 269 * @handle: points to an acpi_pci_root
 270 */
 271static int
 272acpi_pci_slot_add(struct acpi_pci_root *root)
 273{
 274        acpi_status status;
 275
 276        status = walk_root_bridge(root, register_slot);
 277        if (ACPI_FAILURE(status))
 278                err("%s: register_slot failure - %d\n", __func__, status);
 279
 280        return status;
 281}
 282
 283/*
 284 * acpi_pci_slot_remove
 285 * @handle: points to an acpi_pci_root
 286 */
 287static void
 288acpi_pci_slot_remove(struct acpi_pci_root *root)
 289{
 290        struct acpi_pci_slot *slot, *tmp;
 291        struct pci_bus *pbus;
 292        acpi_handle handle = root->device->handle;
 293
 294        mutex_lock(&slot_list_lock);
 295        list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 296                if (slot->root_handle == handle) {
 297                        list_del(&slot->list);
 298                        pbus = slot->pci_slot->bus;
 299                        pci_destroy_slot(slot->pci_slot);
 300                        put_device(&pbus->dev);
 301                        kfree(slot);
 302                }
 303        }
 304        mutex_unlock(&slot_list_lock);
 305}
 306
 307static int do_sta_before_sun(const struct dmi_system_id *d)
 308{
 309        info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
 310        check_sta_before_sun = 1;
 311        return 0;
 312}
 313
 314static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
 315        /*
 316         * Fujitsu Primequest machines will return 1023 to indicate an
 317         * error if the _SUN method is evaluated on SxFy objects that
 318         * are not present (as indicated by _STA), so for those machines,
 319         * we want to check _STA before evaluating _SUN.
 320         */
 321        {
 322         .callback = do_sta_before_sun,
 323         .ident = "Fujitsu PRIMEQUEST",
 324         .matches = {
 325                DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 326                DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 327                },
 328        },
 329        {}
 330};
 331
 332void __init acpi_pci_slot_init(void)
 333{
 334        dmi_check_system(acpi_pci_slot_dmi_table);
 335        acpi_pci_register_driver(&acpi_pci_slot_driver);
 336}
 337
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