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 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 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 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); 366