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