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