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 37 #include "acpiphp.h" 38 #include "pci_hotplug.h" 39 40 #define DRIVER_VERSION "1.0.1" 41 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" 42 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" 43 44 static int debug; 45 46 MODULE_AUTHOR(DRIVER_AUTHOR); 47 MODULE_DESCRIPTION(DRIVER_DESC); 48 MODULE_LICENSE("GPL"); 49 MODULE_VERSION(DRIVER_VERSION); 50 module_param(debug, bool, 0644); 51 MODULE_PARM_DESC(debug, " Debugging mode enabled or not"); 52 #define MY_NAME "acpiphp_ibm" 53 54 #undef dbg 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 FOUND_APCI 0x61504349 63 /* these are the names for the IBM ACPI pseudo-device */ 64 #define IBM_HARDWARE_ID1 "IBM37D0" 65 #define IBM_HARDWARE_ID2 "IBM37D4" 66 67 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun) 68 69 /* union apci_descriptor - allows access to the 70 * various device descriptors that are embedded in the 71 * aPCI table 72 */ 73 union apci_descriptor { 74 struct { 75 char sig[4]; 76 u8 len; 77 } header; 78 struct { 79 u8 type; 80 u8 len; 81 u16 slot_id; 82 u8 bus_id; 83 u8 dev_num; 84 u8 slot_num; 85 u8 slot_attr[2]; 86 u8 attn; 87 u8 status[2]; 88 u8 sun; 89 u8 res[3]; 90 } slot; 91 struct { 92 u8 type; 93 u8 len; 94 } generic; 95 }; 96 97 /* struct notification - keeps info about the device 98 * that cause the ACPI notification event 99 */ 100 struct notification { 101 struct acpi_device *device; 102 u8 event; 103 }; 104 105 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); 106 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); 107 static void ibm_handle_events(acpi_handle handle, u32 event, void *context); 108 static int ibm_get_table_from_acpi(char **bufp); 109 static ssize_t ibm_read_apci_table(struct kobject *kobj, 110 char *buffer, loff_t pos, size_t size); 111 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 112 u32 lvl, void *context, void **rv); 113 static int __init ibm_acpiphp_init(void); 114 static void __exit ibm_acpiphp_exit(void); 115 116 static acpi_handle ibm_acpi_handle; 117 static struct notification ibm_note; 118 static struct bin_attribute ibm_apci_table_attr = { 119 .attr = { 120 .name = "apci_table", 121 .owner = THIS_MODULE, 122 .mode = S_IRUGO, 123 }, 124 .read = ibm_read_apci_table, 125 .write = NULL, 126 }; 127 static struct acpiphp_attention_info ibm_attention_info = 128 { 129 .set_attn = ibm_set_attention_status, 130 .get_attn = ibm_get_attention_status, 131 .owner = THIS_MODULE, 132 }; 133 134 /** 135 * ibm_slot_from_id - workaround for bad ibm hardware 136 * @id: the slot number that linux refers to the slot by 137 * 138 * Description: this method returns the aCPI slot descriptor 139 * corresponding to the Linux slot number. This descriptor 140 * has info about the aPCI slot id and attention status. 141 * This descriptor must be freed using kfree when done. 142 **/ 143 static union apci_descriptor *ibm_slot_from_id(int id) 144 { 145 int ind = 0, size; 146 union apci_descriptor *ret = NULL, *des; 147 char *table; 148 149 size = ibm_get_table_from_acpi(&table); 150 des = (union apci_descriptor *)table; 151 if (memcmp(des->header.sig, "aPCI", 4) != 0) 152 goto ibm_slot_done; 153 154 des = (union apci_descriptor *)&table[ind += des->header.len]; 155 while (ind < size && (des->generic.type != 0x82 || 156 des->slot.slot_num != id)) { 157 des = (union apci_descriptor *)&table[ind += des->generic.len]; 158 } 159 160 if (ind < size && des->slot.slot_num == id) 161 ret = des; 162 163 ibm_slot_done: 164 if (ret) { 165 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); 166 memcpy(ret, des, sizeof(union apci_descriptor)); 167 } 168 kfree(table); 169 return ret; 170 } 171 172 /** 173 * ibm_set_attention_status - callback method to set the attention LED 174 * @slot: the hotplug_slot to work with 175 * @status: what to set the LED to (0 or 1) 176 * 177 * Description: this method is registered with the acpiphp module as a 178 * callback to do the device specific task of setting the LED status 179 **/ 180 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 181 { 182 union acpi_object args[2]; 183 struct acpi_object_list params = { .pointer = args, .count = 2 }; 184 acpi_status stat; 185 unsigned long rc; 186 union apci_descriptor *ibm_slot; 187 188 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 189 190 dbg("%s: set slot %d (%d) attention status to %d\n", __FUNCTION__, 191 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 192 (status ? 1 : 0)); 193 194 args[0].type = ACPI_TYPE_INTEGER; 195 args[0].integer.value = ibm_slot->slot.slot_id; 196 args[1].type = ACPI_TYPE_INTEGER; 197 args[1].integer.value = (status) ? 1 : 0; 198 199 kfree(ibm_slot); 200 201 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); 202 if (ACPI_FAILURE(stat)) { 203 err("APLS evaluation failed: 0x%08x\n", stat); 204 return -ENODEV; 205 } else if (!rc) { 206 err("APLS method failed: 0x%08lx\n", rc); 207 return -ERANGE; 208 } 209 return 0; 210 } 211 212 /** 213 * ibm_get_attention_status - callback method to get attention LED status 214 * @slot: the hotplug_slot to work with 215 * @status: returns what the LED is set to (0 or 1) 216 * 217 * Description: this method is registered with the acpiphp module as a 218 * callback to do the device specific task of getting the LED status 219 * 220 * Because there is no direct method of getting the LED status directly 221 * from an ACPI call, we read the aPCI table and parse out our 222 * slot descriptor to read the status from that. 223 **/ 224 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) 225 { 226 union apci_descriptor *ibm_slot; 227 228 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 229 230 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 231 *status = 1; 232 else 233 *status = 0; 234 235 dbg("%s: get slot %d (%d) attention status is %d\n", __FUNCTION__, 236 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 237 *status); 238 239 kfree(ibm_slot); 240 return 0; 241 } 242 243 /** 244 * ibm_handle_events - listens for ACPI events for the IBM37D0 device 245 * @handle: an ACPI handle to the device that caused the event 246 * @event: the event info (device specific) 247 * @context: passed context (our notification struct) 248 * 249 * Description: this method is registered as a callback with the ACPI 250 * subsystem it is called when this device has an event to notify the OS of 251 * 252 * The events actually come from the device as two events that get 253 * synthesized into one event with data by this function. The event 254 * ID comes first and then the slot number that caused it. We report 255 * this as one event to the OS. 256 * 257 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will 258 * only re-enable the interrupt that causes this event AFTER this method 259 * has returned, thereby enforcing serial access for the notification struct. 260 **/ 261 static void ibm_handle_events(acpi_handle handle, u32 event, void *context) 262 { 263 u8 detail = event & 0x0f; 264 u8 subevent = event & 0xf0; 265 struct notification *note = context; 266 267 dbg("%s: Received notification %02x\n", __FUNCTION__, event); 268 269 if (subevent == 0x80) { 270 dbg("%s: generationg bus event\n", __FUNCTION__); 271 acpi_bus_generate_event(note->device, note->event, detail); 272 } else 273 note->event = event; 274 } 275 276 /** 277 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI 278 * @bufp: address to pointer to allocate for the table 279 * 280 * Description: this method reads the APLS buffer in from ACPI and 281 * stores the "stripped" table into a single buffer 282 * it allocates and passes the address back in bufp 283 * 284 * If NULL is passed in as buffer, this method only calculates 285 * the size of the table and returns that without filling 286 * in the buffer 287 * 288 * returns < 0 on error or the size of the table on success 289 **/ 290 static int ibm_get_table_from_acpi(char **bufp) 291 { 292 union acpi_object *package; 293 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 294 acpi_status status; 295 char *lbuf = NULL; 296 int i, size = -EIO; 297 298 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); 299 if (ACPI_FAILURE(status)) { 300 err("%s: APCI evaluation failed\n", __FUNCTION__); 301 return -ENODEV; 302 } 303 304 package = (union acpi_object *) buffer.pointer; 305 if(!(package) || 306 (package->type != ACPI_TYPE_PACKAGE) || 307 !(package->package.elements)) { 308 err("%s: Invalid APCI object\n", __FUNCTION__); 309 goto read_table_done; 310 } 311 312 for(size = 0, i = 0; i < package->package.count; i++) { 313 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { 314 err("%s: Invalid APCI element %d\n", __FUNCTION__, i); 315 goto read_table_done; 316 } 317 size += package->package.elements[i].buffer.length; 318 } 319 320 if (bufp == NULL) 321 goto read_table_done; 322 323 lbuf = kmalloc(size, GFP_KERNEL); 324 dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", 325 __FUNCTION__, package->package.count, size, lbuf); 326 327 if (lbuf) { 328 *bufp = lbuf; 329 memset(lbuf, 0, size); 330 } else { 331 size = -ENOMEM; 332 goto read_table_done; 333 } 334 335 size = 0; 336 for (i=0; i<package->package.count; i++) { 337 memcpy(&lbuf[size], 338 package->package.elements[i].buffer.pointer, 339 package->package.elements[i].buffer.length); 340 size += package->package.elements[i].buffer.length; 341 } 342 343 read_table_done: 344 kfree(buffer.pointer); 345 return size; 346 } 347 348 /** 349 * ibm_read_apci_table - callback for the sysfs apci_table file 350 * @kobj: the kobject this binary attribute is a part of 351 * @buffer: the kernel space buffer to fill 352 * @pos: the offset into the file 353 * @size: the number of bytes requested 354 * 355 * Description: gets registered with sysfs as the reader callback 356 * to be executed when /sys/bus/pci/slots/apci_table gets read 357 * 358 * Since we don't get notified on open and close for this file, 359 * things get really tricky here... 360 * our solution is to only allow reading the table in all at once 361 **/ 362 static ssize_t ibm_read_apci_table(struct kobject *kobj, 363 char *buffer, loff_t pos, size_t size) 364 { 365 int bytes_read = -EINVAL; 366 char *table = NULL; 367 368 dbg("%s: pos = %d, size = %zd\n", __FUNCTION__, (int)pos, size); 369 370 if (pos == 0) { 371 bytes_read = ibm_get_table_from_acpi(&table); 372 if (bytes_read > 0 && bytes_read <= size) 373 memcpy(buffer, table, bytes_read); 374 kfree(table); 375 } 376 return bytes_read; 377 } 378 379 /** 380 * ibm_find_acpi_device - callback to find our ACPI device 381 * @handle: the ACPI handle of the device we are inspecting 382 * @lvl: depth into the namespace tree 383 * @context: a pointer to our handle to fill when we find the device 384 * @rv: a return value to fill if desired 385 * 386 * Description: used as a callback when calling acpi_walk_namespace 387 * to find our device. When this method returns non-zero 388 * acpi_walk_namespace quits its search and returns our value 389 **/ 390 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 391 u32 lvl, void *context, void **rv) 392 { 393 acpi_handle *phandle = (acpi_handle *)context; 394 acpi_status status; 395 struct acpi_device_info info; 396 struct acpi_buffer info_buffer = { 397 .length = sizeof(struct acpi_device_info), 398 .pointer = &info, 399 }; 400 401 status = acpi_get_object_info(handle, &info_buffer); 402 if (ACPI_FAILURE(status)) { 403 err("%s: Failed to get device information", __FUNCTION__); 404 return 0; 405 } 406 info.hardware_id.value[sizeof(info.hardware_id.value) - 1] = '\0'; 407 408 if(info.current_status && (info.valid & ACPI_VALID_HID) && 409 (!strcmp(info.hardware_id.value, IBM_HARDWARE_ID1) || 410 !strcmp(info.hardware_id.value, IBM_HARDWARE_ID2))) { 411 dbg("found hardware: %s, handle: %p\n", info.hardware_id.value, 412 handle); 413 *phandle = handle; 414 /* returning non-zero causes the search to stop 415 * and returns this value to the caller of 416 * acpi_walk_namespace, but it also causes some warnings 417 * in the acpi debug code to print... 418 */ 419 return FOUND_APCI; 420 } 421 return 0; 422 } 423 424 static int __init ibm_acpiphp_init(void) 425 { 426 int retval = 0; 427 acpi_status status; 428 struct acpi_device *device; 429 struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj; 430 431 dbg("%s\n", __FUNCTION__); 432 433 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 434 ACPI_UINT32_MAX, ibm_find_acpi_device, 435 &ibm_acpi_handle, NULL) != FOUND_APCI) { 436 err("%s: acpi_walk_namespace failed\n", __FUNCTION__); 437 retval = -ENODEV; 438 goto init_return; 439 } 440 dbg("%s: found IBM aPCI device\n", __FUNCTION__); 441 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 442 err("%s: acpi_bus_get_device failed\n", __FUNCTION__); 443 retval = -ENODEV; 444 goto init_return; 445 } 446 if (acpiphp_register_attention(&ibm_attention_info)) { 447 retval = -ENODEV; 448 goto init_return; 449 } 450 451 ibm_note.device = device; 452 status = acpi_install_notify_handler( 453 ibm_acpi_handle, 454 ACPI_DEVICE_NOTIFY, 455 ibm_handle_events, 456 &ibm_note); 457 if (ACPI_FAILURE(status)) { 458 err("%s: Failed to register notification handler\n", 459 __FUNCTION__); 460 retval = -EBUSY; 461 goto init_cleanup; 462 } 463 464 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 465 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 466 467 return retval; 468 469 init_cleanup: 470 acpiphp_unregister_attention(&ibm_attention_info); 471 init_return: 472 return retval; 473 } 474 475 static void __exit ibm_acpiphp_exit(void) 476 { 477 acpi_status status; 478 struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj; 479 480 dbg("%s\n", __FUNCTION__); 481 482 if (acpiphp_unregister_attention(&ibm_attention_info)) 483 err("%s: attention info deregistration failed", __FUNCTION__); 484 485 status = acpi_remove_notify_handler( 486 ibm_acpi_handle, 487 ACPI_DEVICE_NOTIFY, 488 ibm_handle_events); 489 if (ACPI_FAILURE(status)) 490 err("%s: Notification handler removal failed\n", 491 __FUNCTION__); 492 // remove the /sys entries 493 if (sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr)) 494 err("%s: removal of sysfs file apci_table failed\n", 495 __FUNCTION__); 496 } 497 498 module_init(ibm_acpiphp_init); 499 module_exit(ibm_acpiphp_exit); 500