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, 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); 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, NULL, &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, NULL, &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); 372