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 long *sun) 80 { 81 int device = -1; 82 unsigned long 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 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, NULL); 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 get_device(&pci_bus->dev); 168 169 dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n", 170 pci_slot, pci_bus->number, device, name); 171 172 return AE_OK; 173 } 174 175 /* 176 * walk_p2p_bridge - discover and walk p2p bridges 177 * @handle: points to an acpi_pci_root 178 * @context: p2p_bridge_context pointer 179 * 180 * Note that when we call ourselves recursively, we pass a different 181 * value of pci_bus in the child_context. 182 */ 183 static acpi_status 184 walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv) 185 { 186 int device, function; 187 unsigned long long adr; 188 acpi_status status; 189 acpi_handle dummy_handle; 190 acpi_walk_callback user_function; 191 192 struct pci_dev *dev; 193 struct pci_bus *pci_bus; 194 struct callback_args child_context; 195 struct callback_args *parent_context = context; 196 197 pci_bus = parent_context->pci_bus; 198 user_function = parent_context->user_function; 199 200 status = acpi_get_handle(handle, "_ADR", &dummy_handle); 201 if (ACPI_FAILURE(status)) 202 return AE_OK; 203 204 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr); 205 if (ACPI_FAILURE(status)) 206 return AE_OK; 207 208 device = (adr >> 16) & 0xffff; 209 function = adr & 0xffff; 210 211 dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function)); 212 if (!dev || !dev->subordinate) 213 goto out; 214 215 child_context.pci_bus = dev->subordinate; 216 child_context.user_function = user_function; 217 child_context.root_handle = parent_context->root_handle; 218 219 dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number); 220 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, 221 user_function, &child_context, NULL); 222 if (ACPI_FAILURE(status)) 223 goto out; 224 225 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, 226 walk_p2p_bridge, &child_context, NULL); 227 out: 228 pci_dev_put(dev); 229 return AE_OK; 230 } 231 232 /* 233 * walk_root_bridge - generic root bridge walker 234 * @handle: points to an acpi_pci_root 235 * @user_function: user callback for slot objects 236 * 237 * Call user_function for all objects underneath this root bridge. 238 * Walk p2p bridges underneath us and call user_function on those too. 239 */ 240 static int 241 walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function) 242 { 243 int seg, bus; 244 unsigned long long tmp; 245 acpi_status status; 246 acpi_handle dummy_handle; 247 struct pci_bus *pci_bus; 248 struct callback_args context; 249 250 /* If the bridge doesn't have _STA, we assume it is always there */ 251 status = acpi_get_handle(handle, "_STA", &dummy_handle); 252 if (ACPI_SUCCESS(status)) { 253 status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp); 254 if (ACPI_FAILURE(status)) { 255 info("%s: _STA evaluation failure\n", __func__); 256 return 0; 257 } 258 if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0) 259 /* don't register this object */ 260 return 0; 261 } 262 263 status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp); 264 seg = ACPI_SUCCESS(status) ? tmp : 0; 265 266 status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp); 267 bus = ACPI_SUCCESS(status) ? tmp : 0; 268 269 pci_bus = pci_find_bus(seg, bus); 270 if (!pci_bus) 271 return 0; 272 273 context.pci_bus = pci_bus; 274 context.user_function = user_function; 275 context.root_handle = handle; 276 277 dbg("root bridge walk, pci_bus = %x\n", pci_bus->number); 278 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, 279 user_function, &context, NULL); 280 if (ACPI_FAILURE(status)) 281 return status; 282 283 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, 284 walk_p2p_bridge, &context, NULL); 285 if (ACPI_FAILURE(status)) 286 err("%s: walk_p2p_bridge failure - %d\n", __func__, status); 287 288 return status; 289 } 290 291 /* 292 * acpi_pci_slot_add 293 * @handle: points to an acpi_pci_root 294 */ 295 static int 296 acpi_pci_slot_add(acpi_handle handle) 297 { 298 acpi_status status; 299 300 status = walk_root_bridge(handle, register_slot); 301 if (ACPI_FAILURE(status)) 302 err("%s: register_slot failure - %d\n", __func__, status); 303 304 return status; 305 } 306 307 /* 308 * acpi_pci_slot_remove 309 * @handle: points to an acpi_pci_root 310 */ 311 static void 312 acpi_pci_slot_remove(acpi_handle handle) 313 { 314 struct acpi_pci_slot *slot, *tmp; 315 struct pci_bus *pbus; 316 317 mutex_lock(&slot_list_lock); 318 list_for_each_entry_safe(slot, tmp, &slot_list, list) { 319 if (slot->root_handle == handle) { 320 list_del(&slot->list); 321 pbus = slot->pci_slot->bus; 322 pci_destroy_slot(slot->pci_slot); 323 put_device(&pbus->dev); 324 kfree(slot); 325 } 326 } 327 mutex_unlock(&slot_list_lock); 328 } 329 330 static int do_sta_before_sun(const struct dmi_system_id *d) 331 { 332 info("%s detected: will evaluate _STA before calling _SUN\n", d->ident); 333 check_sta_before_sun = 1; 334 return 0; 335 } 336 337 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = { 338 /* 339 * Fujitsu Primequest machines will return 1023 to indicate an 340 * error if the _SUN method is evaluated on SxFy objects that 341 * are not present (as indicated by _STA), so for those machines, 342 * we want to check _STA before evaluating _SUN. 343 */ 344 { 345 .callback = do_sta_before_sun, 346 .ident = "Fujitsu PRIMEQUEST", 347 .matches = { 348 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), 349 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), 350 }, 351 }, 352 {} 353 }; 354 355 static int __init 356 acpi_pci_slot_init(void) 357 { 358 dmi_check_system(acpi_pci_slot_dmi_table); 359 acpi_pci_register_driver(&acpi_pci_slot_driver); 360 return 0; 361 } 362 363 static void __exit 364 acpi_pci_slot_exit(void) 365 { 366 acpi_pci_unregister_driver(&acpi_pci_slot_driver); 367 } 368 369 module_init(acpi_pci_slot_init); 370 module_exit(acpi_pci_slot_exit); 371