drivers/acpi/pci_slot.c

   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/types.h>
  30 #include <linux/pci.h>
  31 #include <linux/acpi.h>
  32 #include <acpi/acpi_bus.h>
  33 #include <acpi/acpi_drivers.h>
  34 #include <linux/dmi.h>
  35
  36 static int debug;
  37 static int check_sta_before_sun;
  38
  39 #define DRIVER_VERSION  "0.1"
  40 #define DRIVER_AUTHOR   "Alex Chiang <achiang@hp.com>"
  41 #define DRIVER_DESC     "ACPI PCI Slot Detection Driver"
  42 MODULE_AUTHOR(DRIVER_AUTHOR);
  43 MODULE_DESCRIPTION(DRIVER_DESC);
  44 MODULE_LICENSE("GPL");
  45 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  46 module_param(debug, bool, 0644);
  47
  48 #define _COMPONENT              ACPI_PCI_COMPONENT
  49 ACPI_MODULE_NAME("pci_slot");
  50
  51 #define MY_NAME "pci_slot"
  52 #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
  53 #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
  54 #define dbg(format, arg...)                                     \
  55         do {                                                    \
  56                 if (debug)                                      \
  57                         printk(KERN_DEBUG "%s: " format,        \
  58                                 MY_NAME , ## arg);              \
  59         } while (0)
  60
  61 #define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  62
  63 struct 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
  69 static int acpi_pci_slot_add(acpi_handle handle);
  70 static void acpi_pci_slot_remove(acpi_handle handle);
  71
  72 static LIST_HEAD(slot_list);
  73 static DEFINE_MUTEX(slot_list_lock);
  74 static struct acpi_pci_driver acpi_pci_slot_driver = {
  75         .add = acpi_pci_slot_add,
  76         .remove = acpi_pci_slot_remove,
  77 };
  78
  79 static int
  80 check_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;
 111 out:
 112         kfree(buffer.pointer);
 113         return device;
 114 }
 115
 116 struct 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  */
 132 static acpi_status
 133 register_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  */
 184 static acpi_status
 185 walk_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, &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, &child_context, NULL);
 228 out:
 229         pci_dev_put(dev);
 230         return AE_OK;
 231 }
 232
 233 /*
 234  * walk_root_bridge - generic root bridge walker
 235  * @handle: points to 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  */
 241 static int
 242 walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
 243 {
 244         int seg, bus;
 245         unsigned long long tmp;
 246         acpi_status status;
 247         acpi_handle dummy_handle;
 248         struct pci_bus *pci_bus;
 249         struct callback_args context;
 250
 251         /* If the bridge doesn't have _STA, we assume it is always there */
 252         status = acpi_get_handle(handle, "_STA", &dummy_handle);
 253         if (ACPI_SUCCESS(status)) {
 254                 status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
 255                 if (ACPI_FAILURE(status)) {
 256                         info("%s: _STA evaluation failure\n", __func__);
 257                         return 0;
 258                 }
 259                 if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
 260                         /* don't register this object */
 261                         return 0;
 262         }
 263
 264         status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
 265         seg = ACPI_SUCCESS(status) ? tmp : 0;
 266
 267         status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
 268         bus = ACPI_SUCCESS(status) ? tmp : 0;
 269
 270         pci_bus = pci_find_bus(seg, bus);
 271         if (!pci_bus)
 272                 return 0;
 273
 274         context.pci_bus = pci_bus;
 275         context.user_function = user_function;
 276         context.root_handle = handle;
 277
 278         dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
 279         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 280                                      user_function, &context, NULL);
 281         if (ACPI_FAILURE(status))
 282                 return status;
 283
 284         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 285                                      walk_p2p_bridge, &context, NULL);
 286         if (ACPI_FAILURE(status))
 287                 err("%s: walk_p2p_bridge failure - %d\n", __func__, status);
 288
 289         return status;
 290 }
 291
 292 /*
 293  * acpi_pci_slot_add
 294  * @handle: points to an acpi_pci_root
 295  */
 296 static int
 297 acpi_pci_slot_add(acpi_handle handle)
 298 {
 299         acpi_status status;
 300
 301         status = walk_root_bridge(handle, register_slot);
 302         if (ACPI_FAILURE(status))
 303                 err("%s: register_slot failure - %d\n", __func__, status);
 304
 305         return status;
 306 }
 307
 308 /*
 309  * acpi_pci_slot_remove
 310  * @handle: points to an acpi_pci_root
 311  */
 312 static void
 313 acpi_pci_slot_remove(acpi_handle handle)
 314 {
 315         struct acpi_pci_slot *slot, *tmp;
 316         struct pci_bus *pbus;
 317
 318         mutex_lock(&slot_list_lock);
 319         list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 320                 if (slot->root_handle == handle) {
 321                         list_del(&slot->list);
 322                         pbus = slot->pci_slot->bus;
 323                         pci_destroy_slot(slot->pci_slot);
 324                         put_device(&pbus->dev);
 325                         kfree(slot);
 326                 }
 327         }
 328         mutex_unlock(&slot_list_lock);
 329 }
 330
 331 static int do_sta_before_sun(const struct dmi_system_id *d)
 332 {
 333         info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
 334         check_sta_before_sun = 1;
 335         return 0;
 336 }
 337
 338 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
 339         /*
 340          * Fujitsu Primequest machines will return 1023 to indicate an
 341          * error if the _SUN method is evaluated on SxFy objects that
 342          * are not present (as indicated by _STA), so for those machines,
 343          * we want to check _STA before evaluating _SUN.
 344          */
 345         {
 346          .callback = do_sta_before_sun,
 347          .ident = "Fujitsu PRIMEQUEST",
 348          .matches = {
 349                 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 350                 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 351                 },
 352         },
 353         {}
 354 };
 355
 356 static int __init
 357 acpi_pci_slot_init(void)
 358 {
 359         dmi_check_system(acpi_pci_slot_dmi_table);
 360         acpi_pci_register_driver(&acpi_pci_slot_driver);
 361         return 0;
 362 }
 363
 364 static void __exit
 365 acpi_pci_slot_exit(void)
 366 {
 367         acpi_pci_unregister_driver(&acpi_pci_slot_driver);
 368 }
 369
 370 module_init(acpi_pci_slot_init);
 371 module_exit(acpi_pci_slot_exit);