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 37 static bool debug; 38 static 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" 43 MODULE_AUTHOR(DRIVER_AUTHOR); 44 MODULE_DESCRIPTION(DRIVER_DESC); 45 MODULE_LICENSE("GPL"); 46 MODULE_PARM_DESC(debug, "Debugging mode enabled or not"); 47 module_param(debug, bool, 0644); 48 49 #define _COMPONENT ACPI_PCI_COMPONENT 50 ACPI_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 64 struct 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 70 static int acpi_pci_slot_add(struct acpi_pci_root *root); 71 static void acpi_pci_slot_remove(struct acpi_pci_root *root); 72 73 static LIST_HEAD(slot_list); 74 static DEFINE_MUTEX(slot_list_lock); 75 static struct acpi_pci_driver acpi_pci_slot_driver = { 76 .add = acpi_pci_slot_add, 77 .remove = acpi_pci_slot_remove, 78 }; 79 80 static int 81 check_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; 112 out: 113 kfree(buffer.pointer); 114 return device; 115 } 116 117 struct 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 */ 133 static acpi_status 134 register_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 */ 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 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); 229 out: 230 pci_dev_put(dev); 231 return AE_OK; 232 } 233 234 /* 235 * walk_root_bridge - generic root bridge walker 236 * @root: poiner of 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(struct acpi_pci_root *root, acpi_walk_callback user_function) 244 { 245 acpi_status status; 246 acpi_handle handle = root->device->handle; 247 struct pci_bus *pci_bus = root->bus; 248 struct callback_args context; 249 250 context.pci_bus = pci_bus; 251 context.user_function = user_function; 252 context.root_handle = handle; 253 254 dbg("root bridge walk, pci_bus = %x\n", pci_bus->number); 255 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, 256 user_function, NULL, &context, NULL); 257 if (ACPI_FAILURE(status)) 258 return status; 259 260 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, 261 walk_p2p_bridge, NULL, &context, NULL); 262 if (ACPI_FAILURE(status)) 263 err("%s: walk_p2p_bridge failure - %d\n", __func__, status); 264 265 return status; 266 } 267 268 /* 269 * acpi_pci_slot_add 270 * @handle: points to an acpi_pci_root 271 */ 272 static int 273 acpi_pci_slot_add(struct acpi_pci_root *root) 274 { 275 acpi_status status; 276 277 status = walk_root_bridge(root, register_slot); 278 if (ACPI_FAILURE(status)) 279 err("%s: register_slot failure - %d\n", __func__, status); 280 281 return status; 282 } 283 284 /* 285 * acpi_pci_slot_remove 286 * @handle: points to an acpi_pci_root 287 */ 288 static void 289 acpi_pci_slot_remove(struct acpi_pci_root *root) 290 { 291 struct acpi_pci_slot *slot, *tmp; 292 struct pci_bus *pbus; 293 acpi_handle handle = root->device->handle; 294 295 mutex_lock(&slot_list_lock); 296 list_for_each_entry_safe(slot, tmp, &slot_list, list) { 297 if (slot->root_handle == handle) { 298 list_del(&slot->list); 299 pbus = slot->pci_slot->bus; 300 pci_destroy_slot(slot->pci_slot); 301 put_device(&pbus->dev); 302 kfree(slot); 303 } 304 } 305 mutex_unlock(&slot_list_lock); 306 } 307 308 static int do_sta_before_sun(const struct dmi_system_id *d) 309 { 310 info("%s detected: will evaluate _STA before calling _SUN\n", d->ident); 311 check_sta_before_sun = 1; 312 return 0; 313 } 314 315 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = { 316 /* 317 * Fujitsu Primequest machines will return 1023 to indicate an 318 * error if the _SUN method is evaluated on SxFy objects that 319 * are not present (as indicated by _STA), so for those machines, 320 * we want to check _STA before evaluating _SUN. 321 */ 322 { 323 .callback = do_sta_before_sun, 324 .ident = "Fujitsu PRIMEQUEST", 325 .matches = { 326 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), 327 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), 328 }, 329 }, 330 {} 331 }; 332 333 static int __init 334 acpi_pci_slot_init(void) 335 { 336 dmi_check_system(acpi_pci_slot_dmi_table); 337 acpi_pci_register_driver(&acpi_pci_slot_driver); 338 return 0; 339 } 340 341 static void __exit 342 acpi_pci_slot_exit(void) 343 { 344 acpi_pci_unregister_driver(&acpi_pci_slot_driver); 345 } 346 347 module_init(acpi_pci_slot_init); 348 module_exit(acpi_pci_slot_exit); 349