1 /* 2 * ACPI PCI Hot Plug IBM Extension 3 * 4 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com> 5 * Copyright (C) 2004 IBM Corp. 6 * 7 * All rights reserved. 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or (at 12 * your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 17 * NON INFRINGEMENT. See the GNU General Public License for more 18 * details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 23 * 24 * Send feedback to <vernux@us.ibm.com> 25 * 26 */ 27 28 #include <linux/init.h> 29 #include <linux/module.h> 30 #include <linux/kernel.h> 31 #include <acpi/acpi_bus.h> 32 #include <linux/sysfs.h> 33 #include <linux/kobject.h> 34 #include <asm/uaccess.h> 35 #include <linux/moduleparam.h> 36 #include <linux/pci.h> 37 38 #include "acpiphp.h" 39 #include "../pci.h" 40 41 #define DRIVER_VERSION "1.0.1" 42 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" 43 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" 44 45 static int debug; 46 47 MODULE_AUTHOR(DRIVER_AUTHOR); 48 MODULE_DESCRIPTION(DRIVER_DESC); 49 MODULE_LICENSE("GPL"); 50 MODULE_VERSION(DRIVER_VERSION); 51 module_param(debug, bool, 0644); 52 MODULE_PARM_DESC(debug, " Debugging mode enabled or not"); 53 #define MY_NAME "acpiphp_ibm" 54 55 #undef dbg 56 #define dbg(format, arg...) \ 57 do { \ 58 if (debug) \ 59 printk(KERN_DEBUG "%s: " format, \ 60 MY_NAME , ## arg); \ 61 } while (0) 62 63 #define FOUND_APCI 0x61504349 64 /* these are the names for the IBM ACPI pseudo-device */ 65 #define IBM_HARDWARE_ID1 "IBM37D0" 66 #define IBM_HARDWARE_ID2 "IBM37D4" 67 68 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun) 69 70 /* union apci_descriptor - allows access to the 71 * various device descriptors that are embedded in the 72 * aPCI table 73 */ 74 union apci_descriptor { 75 struct { 76 char sig[4]; 77 u8 len; 78 } header; 79 struct { 80 u8 type; 81 u8 len; 82 u16 slot_id; 83 u8 bus_id; 84 u8 dev_num; 85 u8 slot_num; 86 u8 slot_attr[2]; 87 u8 attn; 88 u8 status[2]; 89 u8 sun; 90 u8 res[3]; 91 } slot; 92 struct { 93 u8 type; 94 u8 len; 95 } generic; 96 }; 97 98 /* struct notification - keeps info about the device 99 * that cause the ACPI notification event 100 */ 101 struct notification { 102 struct acpi_device *device; 103 u8 event; 104 }; 105 106 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); 107 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); 108 static void ibm_handle_events(acpi_handle handle, u32 event, void *context); 109 static int ibm_get_table_from_acpi(char **bufp); 110 static ssize_t ibm_read_apci_table(struct kobject *kobj, 111 struct bin_attribute *bin_attr, 112 char *buffer, loff_t pos, size_t size); 113 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 114 u32 lvl, void *context, void **rv); 115 static int __init ibm_acpiphp_init(void); 116 static void __exit ibm_acpiphp_exit(void); 117 118 static acpi_handle ibm_acpi_handle; 119 static struct notification ibm_note; 120 static struct bin_attribute ibm_apci_table_attr = { 121 .attr = { 122 .name = "apci_table", 123 .mode = S_IRUGO, 124 }, 125 .read = ibm_read_apci_table, 126 .write = NULL, 127 }; 128 static struct acpiphp_attention_info ibm_attention_info = 129 { 130 .set_attn = ibm_set_attention_status, 131 .get_attn = ibm_get_attention_status, 132 .owner = THIS_MODULE, 133 }; 134 135 /** 136 * ibm_slot_from_id - workaround for bad ibm hardware 137 * @id: the slot number that linux refers to the slot by 138 * 139 * Description: This method returns the aCPI slot descriptor 140 * corresponding to the Linux slot number. This descriptor 141 * has info about the aPCI slot id and attention status. 142 * This descriptor must be freed using kfree when done. 143 */ 144 static union apci_descriptor *ibm_slot_from_id(int id) 145 { 146 int ind = 0, size; 147 union apci_descriptor *ret = NULL, *des; 148 char *table; 149 150 size = ibm_get_table_from_acpi(&table); 151 des = (union apci_descriptor *)table; 152 if (memcmp(des->header.sig, "aPCI", 4) != 0) 153 goto ibm_slot_done; 154 155 des = (union apci_descriptor *)&table[ind += des->header.len]; 156 while (ind < size && (des->generic.type != 0x82 || 157 des->slot.slot_num != id)) { 158 des = (union apci_descriptor *)&table[ind += des->generic.len]; 159 } 160 161 if (ind < size && des->slot.slot_num == id) 162 ret = des; 163 164 ibm_slot_done: 165 if (ret) { 166 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); 167 memcpy(ret, des, sizeof(union apci_descriptor)); 168 } 169 kfree(table); 170 return ret; 171 } 172 173 /** 174 * ibm_set_attention_status - callback method to set the attention LED 175 * @slot: the hotplug_slot to work with 176 * @status: what to set the LED to (0 or 1) 177 * 178 * Description: This method is registered with the acpiphp module as a 179 * callback to do the device specific task of setting the LED status. 180 */ 181 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 182 { 183 union acpi_object args[2]; 184 struct acpi_object_list params = { .pointer = args, .count = 2 }; 185 acpi_status stat; 186 unsigned long long rc; 187 union apci_descriptor *ibm_slot; 188 189 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 190 191 dbg("%s: set slot %d (%d) attention status to %d\n", __func__, 192 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 193 (status ? 1 : 0)); 194 195 args[0].type = ACPI_TYPE_INTEGER; 196 args[0].integer.value = ibm_slot->slot.slot_id; 197 args[1].type = ACPI_TYPE_INTEGER; 198 args[1].integer.value = (status) ? 1 : 0; 199 200 kfree(ibm_slot); 201 202 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); 203 if (ACPI_FAILURE(stat)) { 204 err("APLS evaluation failed: 0x%08x\n", stat); 205 return -ENODEV; 206 } else if (!rc) { 207 err("APLS method failed: 0x%08llx\n", rc); 208 return -ERANGE; 209 } 210 return 0; 211 } 212 213 /** 214 * ibm_get_attention_status - callback method to get attention LED status 215 * @slot: the hotplug_slot to work with 216 * @status: returns what the LED is set to (0 or 1) 217 * 218 * Description: This method is registered with the acpiphp module as a 219 * callback to do the device specific task of getting the LED status. 220 * 221 * Because there is no direct method of getting the LED status directly 222 * from an ACPI call, we read the aPCI table and parse out our 223 * slot descriptor to read the status from that. 224 */ 225 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) 226 { 227 union apci_descriptor *ibm_slot; 228 229 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 230 231 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 232 *status = 1; 233 else 234 *status = 0; 235 236 dbg("%s: get slot %d (%d) attention status is %d\n", __func__, 237 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 238 *status); 239 240 kfree(ibm_slot); 241 return 0; 242 } 243 244 /** 245 * ibm_handle_events - listens for ACPI events for the IBM37D0 device 246 * @handle: an ACPI handle to the device that caused the event 247 * @event: the event info (device specific) 248 * @context: passed context (our notification struct) 249 * 250 * Description: This method is registered as a callback with the ACPI 251 * subsystem it is called when this device has an event to notify the OS of. 252 * 253 * The events actually come from the device as two events that get 254 * synthesized into one event with data by this function. The event 255 * ID comes first and then the slot number that caused it. We report 256 * this as one event to the OS. 257 * 258 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will 259 * only re-enable the interrupt that causes this event AFTER this method 260 * has returned, thereby enforcing serial access for the notification struct. 261 */ 262 static void ibm_handle_events(acpi_handle handle, u32 event, void *context) 263 { 264 u8 detail = event & 0x0f; 265 u8 subevent = event & 0xf0; 266 struct notification *note = context; 267 268 dbg("%s: Received notification %02x\n", __func__, event); 269 270 if (subevent == 0x80) { 271 dbg("%s: generationg bus event\n", __func__); 272 acpi_bus_generate_proc_event(note->device, note->event, detail); 273 acpi_bus_generate_netlink_event(note->device->pnp.device_class, 274 dev_name(¬e->device->dev), 275 note->event, detail); 276 } else 277 note->event = event; 278 } 279 280 /** 281 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI 282 * @bufp: address to pointer to allocate for the table 283 * 284 * Description: This method reads the APLS buffer in from ACPI and 285 * stores the "stripped" table into a single buffer 286 * it allocates and passes the address back in bufp. 287 * 288 * If NULL is passed in as buffer, this method only calculates 289 * the size of the table and returns that without filling 290 * in the buffer. 291 * 292 * Returns < 0 on error or the size of the table on success. 293 */ 294 static int ibm_get_table_from_acpi(char **bufp) 295 { 296 union acpi_object *package; 297 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 298 acpi_status status; 299 char *lbuf = NULL; 300 int i, size = -EIO; 301 302 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); 303 if (ACPI_FAILURE(status)) { 304 err("%s: APCI evaluation failed\n", __func__); 305 return -ENODEV; 306 } 307 308 package = (union acpi_object *) buffer.pointer; 309 if (!(package) || 310 (package->type != ACPI_TYPE_PACKAGE) || 311 !(package->package.elements)) { 312 err("%s: Invalid APCI object\n", __func__); 313 goto read_table_done; 314 } 315 316 for(size = 0, i = 0; i < package->package.count; i++) { 317 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { 318 err("%s: Invalid APCI element %d\n", __func__, i); 319 goto read_table_done; 320 } 321 size += package->package.elements[i].buffer.length; 322 } 323 324 if (bufp == NULL) 325 goto read_table_done; 326 327 lbuf = kzalloc(size, GFP_KERNEL); 328 dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", 329 __func__, package->package.count, size, lbuf); 330 331 if (lbuf) { 332 *bufp = lbuf; 333 } else { 334 size = -ENOMEM; 335 goto read_table_done; 336 } 337 338 size = 0; 339 for (i=0; i<package->package.count; i++) { 340 memcpy(&lbuf[size], 341 package->package.elements[i].buffer.pointer, 342 package->package.elements[i].buffer.length); 343 size += package->package.elements[i].buffer.length; 344 } 345 346 read_table_done: 347 kfree(buffer.pointer); 348 return size; 349 } 350 351 /** 352 * ibm_read_apci_table - callback for the sysfs apci_table file 353 * @kobj: the kobject this binary attribute is a part of 354 * @bin_attr: struct bin_attribute for this file 355 * @buffer: the kernel space buffer to fill 356 * @pos: the offset into the file 357 * @size: the number of bytes requested 358 * 359 * Description: Gets registered with sysfs as the reader callback 360 * to be executed when /sys/bus/pci/slots/apci_table gets read. 361 * 362 * Since we don't get notified on open and close for this file, 363 * things get really tricky here... 364 * our solution is to only allow reading the table in all at once. 365 */ 366 static ssize_t ibm_read_apci_table(struct kobject *kobj, 367 struct bin_attribute *bin_attr, 368 char *buffer, loff_t pos, size_t size) 369 { 370 int bytes_read = -EINVAL; 371 char *table = NULL; 372 373 dbg("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); 374 375 if (pos == 0) { 376 bytes_read = ibm_get_table_from_acpi(&table); 377 if (bytes_read > 0 && bytes_read <= size) 378 memcpy(buffer, table, bytes_read); 379 kfree(table); 380 } 381 return bytes_read; 382 } 383 384 /** 385 * ibm_find_acpi_device - callback to find our ACPI device 386 * @handle: the ACPI handle of the device we are inspecting 387 * @lvl: depth into the namespace tree 388 * @context: a pointer to our handle to fill when we find the device 389 * @rv: a return value to fill if desired 390 * 391 * Description: Used as a callback when calling acpi_walk_namespace 392 * to find our device. When this method returns non-zero 393 * acpi_walk_namespace quits its search and returns our value. 394 */ 395 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 396 u32 lvl, void *context, void **rv) 397 { 398 acpi_handle *phandle = (acpi_handle *)context; 399 acpi_status status; 400 struct acpi_device_info *info; 401 int retval = 0; 402 403 status = acpi_get_object_info(handle, &info); 404 if (ACPI_FAILURE(status)) { 405 err("%s: Failed to get device information status=0x%x\n", 406 __func__, status); 407 return retval; 408 } 409 410 if (info->current_status && (info->valid & ACPI_VALID_HID) && 411 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || 412 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { 413 dbg("found hardware: %s, handle: %p\n", 414 info->hardware_id.string, handle); 415 *phandle = handle; 416 /* returning non-zero causes the search to stop 417 * and returns this value to the caller of 418 * acpi_walk_namespace, but it also causes some warnings 419 * in the acpi debug code to print... 420 */ 421 retval = FOUND_APCI; 422 } 423 kfree(info); 424 return retval; 425 } 426 427 static int __init ibm_acpiphp_init(void) 428 { 429 int retval = 0; 430 acpi_status status; 431 struct acpi_device *device; 432 struct kobject *sysdir = &pci_slots_kset->kobj; 433 434 dbg("%s\n", __func__); 435 436 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 437 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, 438 &ibm_acpi_handle, NULL) != FOUND_APCI) { 439 err("%s: acpi_walk_namespace failed\n", __func__); 440 retval = -ENODEV; 441 goto init_return; 442 } 443 dbg("%s: found IBM aPCI device\n", __func__); 444 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 445 err("%s: acpi_bus_get_device failed\n", __func__); 446 retval = -ENODEV; 447 goto init_return; 448 } 449 if (acpiphp_register_attention(&ibm_attention_info)) { 450 retval = -ENODEV; 451 goto init_return; 452 } 453 454 ibm_note.device = device; 455 status = acpi_install_notify_handler(ibm_acpi_handle, 456 ACPI_DEVICE_NOTIFY, ibm_handle_events, 457 &ibm_note); 458 if (ACPI_FAILURE(status)) { 459 err("%s: Failed to register notification handler\n", 460 __func__); 461 retval = -EBUSY; 462 goto init_cleanup; 463 } 464 465 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 466 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 467 468 return retval; 469 470 init_cleanup: 471 acpiphp_unregister_attention(&ibm_attention_info); 472 init_return: 473 return retval; 474 } 475 476 static void __exit ibm_acpiphp_exit(void) 477 { 478 acpi_status status; 479 struct kobject *sysdir = &pci_slots_kset->kobj; 480 481 dbg("%s\n", __func__); 482 483 if (acpiphp_unregister_attention(&ibm_attention_info)) 484 err("%s: attention info deregistration failed", __func__); 485 486 status = acpi_remove_notify_handler( 487 ibm_acpi_handle, 488 ACPI_DEVICE_NOTIFY, 489 ibm_handle_events); 490 if (ACPI_FAILURE(status)) 491 err("%s: Notification handler removal failed\n", __func__); 492 /* remove the /sys entries */ 493 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); 494 } 495 496 module_init(ibm_acpiphp_init); 497 module_exit(ibm_acpiphp_exit); 498