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, int *device, unsigned long *sun) 80 { 81 int retval = 0; 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 retval = -1; 94 goto out; 95 } 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 retval = -1; 102 goto out; 103 } 104 105 *device = (adr >> 16) & 0xffff; 106 107 /* No _SUN == not a slot == bail */ 108 status = acpi_evaluate_integer(handle, "_SUN", NULL, sun); 109 if (ACPI_FAILURE(status)) { 110 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer); 111 retval = -1; 112 goto out; 113 } 114 115 out: 116 kfree(buffer.pointer); 117 return retval; 118 } 119 120 struct callback_args { 121 acpi_walk_callback user_function; /* only for walk_p2p_bridge */ 122 struct pci_bus *pci_bus; 123 acpi_handle root_handle; 124 }; 125 126 /* 127 * register_slot 128 * 129 * Called once for each SxFy object in the namespace. Don't worry about 130 * calling pci_create_slot multiple times for the same pci_bus:device, 131 * since each subsequent call simply bumps the refcount on the pci_slot. 132 * 133 * The number of calls to pci_destroy_slot from unregister_slot is 134 * symmetrical. 135 */ 136 static acpi_status 137 register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) 138 { 139 int device; 140 unsigned long sun; 141 char name[SLOT_NAME_SIZE]; 142 struct acpi_pci_slot *slot; 143 struct pci_slot *pci_slot; 144 struct callback_args *parent_context = context; 145 struct pci_bus *pci_bus = parent_context->pci_bus; 146 147 if (check_slot(handle, &device, &sun)) 148 return AE_OK; 149 150 slot = kmalloc(sizeof(*slot), GFP_KERNEL); 151 if (!slot) { 152 err("%s: cannot allocate memory\n", __func__); 153 return AE_OK; 154 } 155 156 snprintf(name, sizeof(name), "%u", (u32)sun); 157 pci_slot = pci_create_slot(pci_bus, device, name); 158 if (IS_ERR(pci_slot)) { 159 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot)); 160 kfree(slot); 161 return AE_OK; 162 } 163 164 slot->root_handle = parent_context->root_handle; 165 slot->pci_slot = pci_slot; 166 INIT_LIST_HEAD(&slot->list); 167 mutex_lock(&slot_list_lock); 168 list_add(&slot->list, &slot_list); 169 mutex_unlock(&slot_list_lock); 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 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, &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, &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 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, &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, &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; 317 318 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 pci_destroy_slot(slot->pci_slot); 323 kfree(slot); 324 } 325 } 326 mutex_unlock(&slot_list_lock); 327 } 328 329 static int do_sta_before_sun(const struct dmi_system_id *d) 330 { 331 info("%s detected: will evaluate _STA before calling _SUN\n", d->ident); 332 check_sta_before_sun = 1; 333 return 0; 334 } 335 336 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = { 337 /* 338 * Fujitsu Primequest machines will return 1023 to indicate an 339 * error if the _SUN method is evaluated on SxFy objects that 340 * are not present (as indicated by _STA), so for those machines, 341 * we want to check _STA before evaluating _SUN. 342 */ 343 { 344 .callback = do_sta_before_sun, 345 .ident = "Fujitsu PRIMEQUEST", 346 .matches = { 347 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), 348 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), 349 }, 350 }, 351 {} 352 }; 353 354 static int __init 355 acpi_pci_slot_init(void) 356 { 357 dmi_check_system(acpi_pci_slot_dmi_table); 358 acpi_pci_register_driver(&acpi_pci_slot_driver); 359 return 0; 360 } 361 362 static void __exit 363 acpi_pci_slot_exit(void) 364 { 365 acpi_pci_unregister_driver(&acpi_pci_slot_driver); 366 } 367 368 module_init(acpi_pci_slot_init); 369 module_exit(acpi_pci_slot_exit); 370