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
  35 static int debug;
  36 static int check_sta_before_sun;
  37
  38 #define DRIVER_VERSION  "0.1"
  39 #define DRIVER_AUTHOR   "Alex Chiang <achiang@hp.com>"
  40 #define DRIVER_DESC     "ACPI PCI Slot Detection Driver"
  41 MODULE_AUTHOR(DRIVER_AUTHOR);
  42 MODULE_DESCRIPTION(DRIVER_DESC);
  43 MODULE_LICENSE("GPL");
  44 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  45 module_param(debug, bool, 0644);
  46
  47 #define _COMPONENT              ACPI_PCI_COMPONENT
  48 ACPI_MODULE_NAME("pci_slot");
  49
  50 #define MY_NAME "pci_slot"
  51 #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
  52 #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
  53 #define dbg(format, arg...)                                     \
  54         do {                                                    \
  55                 if (debug)                                      \
  56                         printk(KERN_DEBUG "%s: " format,        \
  57                                 MY_NAME , ## arg);              \
  58         } while (0)
  59
  60 #define SLOT_NAME_SIZE 20               /* Inspired by #define in acpiphp.h */
  61
  62 struct acpi_pci_slot {
  63         acpi_handle root_handle;        /* handle of the root bridge */
  64         struct pci_slot *pci_slot;      /* corresponding pci_slot */
  65         struct list_head list;          /* node in the list of slots */
  66 };
  67
  68 static int acpi_pci_slot_add(acpi_handle handle);
  69 static void acpi_pci_slot_remove(acpi_handle handle);
  70
  71 static LIST_HEAD(slot_list);
  72 static DEFINE_MUTEX(slot_list_lock);
  73 static struct acpi_pci_driver acpi_pci_slot_driver = {
  74         .add = acpi_pci_slot_add,
  75         .remove = acpi_pci_slot_remove,
  76 };
  77
  78 static int
  79 check_slot(acpi_handle handle, unsigned long *sun)
  80 {
  81         int device = -1;
  82         unsigned long adr, sta;
  83         acpi_status status;
  84         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  85
  86         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
  87         dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
  88
  89         if (check_sta_before_sun) {
  90                 /* If SxFy doesn't have _STA, we just assume it's there */
  91                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  92                 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
  93                         goto out;
  94         }
  95
  96         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
  97         if (ACPI_FAILURE(status)) {
  98                 dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
  99                 goto out;
 100         }
 101
 102         /* No _SUN == not a slot == bail */
 103         status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
 104         if (ACPI_FAILURE(status)) {
 105                 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
 106                 goto out;
 107         }
 108
 109         device = (adr >> 16) & 0xffff;
 110 out:
 111         kfree(buffer.pointer);
 112         return device;
 113 }
 114
 115 struct callback_args {
 116         acpi_walk_callback      user_function;  /* only for walk_p2p_bridge */
 117         struct pci_bus          *pci_bus;
 118         acpi_handle             root_handle;
 119 };
 120
 121 /*
 122  * register_slot
 123  *
 124  * Called once for each SxFy object in the namespace. Don't worry about
 125  * calling pci_create_slot multiple times for the same pci_bus:device,
 126  * since each subsequent call simply bumps the refcount on the pci_slot.
 127  *
 128  * The number of calls to pci_destroy_slot from unregister_slot is
 129  * symmetrical.
 130  */
 131 static acpi_status
 132 register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 133 {
 134         int device;
 135         unsigned long sun;
 136         char name[SLOT_NAME_SIZE];
 137         struct acpi_pci_slot *slot;
 138         struct pci_slot *pci_slot;
 139         struct callback_args *parent_context = context;
 140         struct pci_bus *pci_bus = parent_context->pci_bus;
 141
 142         device = check_slot(handle, &sun);
 143         if (device < 0)
 144                 return AE_OK;
 145
 146         slot = kmalloc(sizeof(*slot), GFP_KERNEL);
 147         if (!slot) {
 148                 err("%s: cannot allocate memory\n", __func__);
 149                 return AE_OK;
 150         }
 151
 152         snprintf(name, sizeof(name), "%u", (u32)sun);
 153         pci_slot = pci_create_slot(pci_bus, device, name);
 154         if (IS_ERR(pci_slot)) {
 155                 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
 156                 kfree(slot);
 157                 return AE_OK;
 158         }
 159
 160         slot->root_handle = parent_context->root_handle;
 161         slot->pci_slot = pci_slot;
 162         INIT_LIST_HEAD(&slot->list);
 163         mutex_lock(&slot_list_lock);
 164         list_add(&slot->list, &slot_list);
 165         mutex_unlock(&slot_list_lock);
 166
 167         dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
 168                 pci_slot, pci_bus->number, device, name);
 169
 170         return AE_OK;
 171 }
 172
 173 /*
 174  * walk_p2p_bridge - discover and walk p2p bridges
 175  * @handle: points to an acpi_pci_root
 176  * @context: p2p_bridge_context pointer
 177  *
 178  * Note that when we call ourselves recursively, we pass a different
 179  * value of pci_bus in the child_context.
 180  */
 181 static acpi_status
 182 walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
 183 {
 184         int device, function;
 185         unsigned long adr;
 186         acpi_status status;
 187         acpi_handle dummy_handle;
 188         acpi_walk_callback user_function;
 189
 190         struct pci_dev *dev;
 191         struct pci_bus *pci_bus;
 192         struct callback_args child_context;
 193         struct callback_args *parent_context = context;
 194
 195         pci_bus = parent_context->pci_bus;
 196         user_function = parent_context->user_function;
 197
 198         status = acpi_get_handle(handle, "_ADR", &dummy_handle);
 199         if (ACPI_FAILURE(status))
 200                 return AE_OK;
 201
 202         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 203         if (ACPI_FAILURE(status))
 204                 return AE_OK;
 205
 206         device = (adr >> 16) & 0xffff;
 207         function = adr & 0xffff;
 208
 209         dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
 210         if (!dev || !dev->subordinate)
 211                 goto out;
 212
 213         child_context.pci_bus = dev->subordinate;
 214         child_context.user_function = user_function;
 215         child_context.root_handle = parent_context->root_handle;
 216
 217         dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
 218         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 219                                      user_function, &child_context, NULL);
 220         if (ACPI_FAILURE(status))
 221                 goto out;
 222
 223         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 224                                      walk_p2p_bridge, &child_context, NULL);
 225 out:
 226         pci_dev_put(dev);
 227         return AE_OK;
 228 }
 229
 230 /*
 231  * walk_root_bridge - generic root bridge walker
 232  * @handle: points to an acpi_pci_root
 233  * @user_function: user callback for slot objects
 234  *
 235  * Call user_function for all objects underneath this root bridge.
 236  * Walk p2p bridges underneath us and call user_function on those too.
 237  */
 238 static int
 239 walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
 240 {
 241         int seg, bus;
 242         unsigned long tmp;
 243         acpi_status status;
 244         acpi_handle dummy_handle;
 245         struct pci_bus *pci_bus;
 246         struct callback_args context;
 247
 248         /* If the bridge doesn't have _STA, we assume it is always there */
 249         status = acpi_get_handle(handle, "_STA", &dummy_handle);
 250         if (ACPI_SUCCESS(status)) {
 251                 status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
 252                 if (ACPI_FAILURE(status)) {
 253                         info("%s: _STA evaluation failure\n", __func__);
 254                         return 0;
 255                 }
 256                 if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
 257                         /* don't register this object */
 258                         return 0;
 259         }
 260
 261         status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
 262         seg = ACPI_SUCCESS(status) ? tmp : 0;
 263
 264         status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
 265         bus = ACPI_SUCCESS(status) ? tmp : 0;
 266
 267         pci_bus = pci_find_bus(seg, bus);
 268         if (!pci_bus)
 269                 return 0;
 270
 271         context.pci_bus = pci_bus;
 272         context.user_function = user_function;
 273         context.root_handle = handle;
 274
 275         dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
 276         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 277                                      user_function, &context, NULL);
 278         if (ACPI_FAILURE(status))
 279                 return status;
 280
 281         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 282                                      walk_p2p_bridge, &context, NULL);
 283         if (ACPI_FAILURE(status))
 284                 err("%s: walk_p2p_bridge failure - %d\n", __func__, status);
 285
 286         return status;
 287 }
 288
 289 /*
 290  * acpi_pci_slot_add
 291  * @handle: points to an acpi_pci_root
 292  */
 293 static int
 294 acpi_pci_slot_add(acpi_handle handle)
 295 {
 296         acpi_status status;
 297
 298         status = walk_root_bridge(handle, register_slot);
 299         if (ACPI_FAILURE(status))
 300                 err("%s: register_slot failure - %d\n", __func__, status);
 301
 302         return status;
 303 }
 304
 305 /*
 306  * acpi_pci_slot_remove
 307  * @handle: points to an acpi_pci_root
 308  */
 309 static void
 310 acpi_pci_slot_remove(acpi_handle handle)
 311 {
 312         struct acpi_pci_slot *slot, *tmp;
 313
 314         mutex_lock(&slot_list_lock);
 315         list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 316                 if (slot->root_handle == handle) {
 317                         list_del(&slot->list);
 318                         pci_destroy_slot(slot->pci_slot);
 319                         kfree(slot);
 320                 }
 321         }
 322         mutex_unlock(&slot_list_lock);
 323 }
 324
 325 static int do_sta_before_sun(const struct dmi_system_id *d)
 326 {
 327         info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
 328         check_sta_before_sun = 1;
 329         return 0;
 330 }
 331
 332 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
 333         /*
 334          * Fujitsu Primequest machines will return 1023 to indicate an
 335          * error if the _SUN method is evaluated on SxFy objects that
 336          * are not present (as indicated by _STA), so for those machines,
 337          * we want to check _STA before evaluating _SUN.
 338          */
 339         {
 340          .callback = do_sta_before_sun,
 341          .ident = "Fujitsu PRIMEQUEST",
 342          .matches = {
 343                 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 344                 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 345                 },
 346         },
 347         {}
 348 };
 349
 350 static int __init
 351 acpi_pci_slot_init(void)
 352 {
 353         dmi_check_system(acpi_pci_slot_dmi_table);
 354         acpi_pci_register_driver(&acpi_pci_slot_driver);
 355         return 0;
 356 }
 357
 358 static void __exit
 359 acpi_pci_slot_exit(void)
 360 {
 361         acpi_pci_unregister_driver(&acpi_pci_slot_driver);
 362 }
 363
 364 module_init(acpi_pci_slot_init);
 365 module_exit(acpi_pci_slot_exit);