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/slab.h> 30#include <linux/types.h> 31#include <linux/pci.h> 32#include <linux/acpi.h> 33#include <acpi/acpi_bus.h> 34#include <acpi/acpi_drivers.h> 35#include <linux/dmi.h> 36 37static int debug; 38static int check_sta_before_sun; 39 40#define DRIVER_VERSION "0.1" 41#define DRIVER_AUTHOR "Alex Chiang <achiang@hp.com>" 42#define DRIVER_DESC "ACPI PCI Slot Detection Driver" 43MODULE_AUTHOR(DRIVER_AUTHOR); 44MODULE_DESCRIPTION(DRIVER_DESC); 45MODULE_LICENSE("GPL"); 46MODULE_PARM_DESC(debug, "Debugging mode enabled or not"); 47module_param(debug, bool, 0644); 48 49#define _COMPONENT ACPI_PCI_COMPONENT 50ACPI_MODULE_NAME("pci_slot"); 51 52#define MY_NAME "pci_slot" 53#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg) 54#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg) 55#define dbg(format, arg...) \ 56 do { \ 57 if (debug) \ 58 printk(KERN_DEBUG "%s: " format, \ 59 MY_NAME , ## arg); \ 60 } while (0) 61 62#define SLOT_NAME_SIZE 21 /* Inspired by #define in acpiphp.h */ 63 64struct acpi_pci_slot { 65 acpi_handle root_handle; /* handle of the root bridge */ 66 struct pci_slot *pci_slot; /* corresponding pci_slot */ 67 struct list_head list; /* node in the list of slots */ 68}; 69 70static int acpi_pci_slot_add(acpi_handle handle); 71static void acpi_pci_slot_remove(acpi_handle handle); 72 73static LIST_HEAD(slot_list); 74static DEFINE_MUTEX(slot_list_lock); 75static struct acpi_pci_driver acpi_pci_slot_driver = { 76 .add = acpi_pci_slot_add, 77 .remove = acpi_pci_slot_remove, 78}; 79 80static int 81check_slot(acpi_handle handle, unsigned long long *sun) 82{ 83 int device = -1; 84 unsigned long long adr, sta; 85 acpi_status status; 86 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 87 88 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 89 dbg("Checking slot on path: %s\n", (char *)buffer.pointer); 90 91 if (check_sta_before_sun) { 92 /* If SxFy doesn't have _STA, we just assume it's there */ 93 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); 94 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) 95 goto out; 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 goto out; 102 } 103 104 /* No _SUN == not a slot == bail */ 105 status = acpi_evaluate_integer(handle, "_SUN", NULL, sun); 106 if (ACPI_FAILURE(status)) { 107 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer); 108 goto out; 109 } 110 111 device = (adr >> 16) & 0xffff; 112out: 113 kfree(buffer.pointer); 114 return device; 115} 116 117struct callback_args { 118 acpi_walk_callback user_function; /* only for walk_p2p_bridge */ 119 struct pci_bus *pci_bus; 120 acpi_handle root_handle; 121}; 122 123/* 124 * register_slot 125 * 126 * Called once for each SxFy object in the namespace. Don't worry about 127 * calling pci_create_slot multiple times for the same pci_bus:device, 128 * since each subsequent call simply bumps the refcount on the pci_slot. 129 * 130 * The number of calls to pci_destroy_slot from unregister_slot is 131 * symmetrical. 132 */ 133static acpi_status 134register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) 135{ 136 int device; 137 unsigned long long sun; 138 char name[SLOT_NAME_SIZE]; 139 struct acpi_pci_slot *slot; 140 struct pci_slot *pci_slot; 141 struct callback_args *parent_context = context; 142 struct pci_bus *pci_bus = parent_context->pci_bus; 143 144 device = check_slot(handle, &sun); 145 if (device < 0) 146 return AE_OK; 147 148 slot = kmalloc(sizeof(*slot), GFP_KERNEL); 149 if (!slot) { 150 err("%s: cannot allocate memory\n", __func__); 151 return AE_OK; 152 } 153 154 snprintf(name, sizeof(name), "%llu", sun); 155 pci_slot = pci_create_slot(pci_bus, device, name, NULL); 156 if (IS_ERR(pci_slot)) { 157 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot)); 158 kfree(slot); 159 return AE_OK; 160 } 161 162 slot->root_handle = parent_context->root_handle; 163 slot->pci_slot = pci_slot; 164 INIT_LIST_HEAD(&slot->list); 165 mutex_lock(&slot_list_lock); 166 list_add(&slot->list, &slot_list); 167 mutex_unlock(&slot_list_lock); 168 169 get_device(&pci_bus->dev); 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 */ 185static acpi_status 186walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv) 187{ 188 int device, function; 189 unsigned long 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, NULL, &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, NULL, &child_context, NULL); 229out: 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 */ 242static int 243walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function) 244{ 245 int seg, bus; 246 unsigned long 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, NULL, &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, NULL, &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 */ 297static int 298acpi_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 */ 313static void 314acpi_pci_slot_remove(acpi_handle handle) 315{ 316 struct acpi_pci_slot *slot, *tmp; 317 struct pci_bus *pbus; 318 319 mutex_lock(&slot_list_lock); 320 list_for_each_entry_safe(slot, tmp, &slot_list, list) { 321 if (slot->root_handle == handle) { 322 list_del(&slot->list); 323 pbus = slot->pci_slot->bus; 324 pci_destroy_slot(slot->pci_slot); 325 put_device(&pbus->dev); 326 kfree(slot); 327 } 328 } 329 mutex_unlock(&slot_list_lock); 330} 331 332static int do_sta_before_sun(const struct dmi_system_id *d) 333{ 334 info("%s detected: will evaluate _STA before calling _SUN\n", d->ident); 335 check_sta_before_sun = 1; 336 return 0; 337} 338 339static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = { 340 /* 341 * Fujitsu Primequest machines will return 1023 to indicate an 342 * error if the _SUN method is evaluated on SxFy objects that 343 * are not present (as indicated by _STA), so for those machines, 344 * we want to check _STA before evaluating _SUN. 345 */ 346 { 347 .callback = do_sta_before_sun, 348 .ident = "Fujitsu PRIMEQUEST", 349 .matches = { 350 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), 351 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), 352 }, 353 }, 354 {} 355}; 356 357static int __init 358acpi_pci_slot_init(void) 359{ 360 dmi_check_system(acpi_pci_slot_dmi_table); 361 acpi_pci_register_driver(&acpi_pci_slot_driver); 362 return 0; 363} 364 365static void __exit 366acpi_pci_slot_exit(void) 367{ 368 acpi_pci_unregister_driver(&acpi_pci_slot_driver); 369} 370 371module_init(acpi_pci_slot_init); 372module_exit(acpi_pci_slot_exit); 373