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 #define pr_fmt(fmt) "acpiphp_ibm: " fmt 29 30 #include <linux/init.h> 31 #include <linux/slab.h> 32 #include <linux/module.h> 33 #include <linux/kernel.h> 34 #include <linux/sysfs.h> 35 #include <linux/kobject.h> 36 #include <linux/moduleparam.h> 37 #include <linux/pci.h> 38 #include <linux/uaccess.h> 39 40 #include "acpiphp.h" 41 #include "../pci.h" 42 43 #define DRIVER_VERSION "1.0.1" 44 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" 45 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" 46 47 48 MODULE_AUTHOR(DRIVER_AUTHOR); 49 MODULE_DESCRIPTION(DRIVER_DESC); 50 MODULE_LICENSE("GPL"); 51 MODULE_VERSION(DRIVER_VERSION); 52 53 #define FOUND_APCI 0x61504349 54 /* these are the names for the IBM ACPI pseudo-device */ 55 #define IBM_HARDWARE_ID1 "IBM37D0" 56 #define IBM_HARDWARE_ID2 "IBM37D4" 57 58 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun) 59 60 /* union apci_descriptor - allows access to the 61 * various device descriptors that are embedded in the 62 * aPCI table 63 */ 64 union apci_descriptor { 65 struct { 66 char sig[4]; 67 u8 len; 68 } header; 69 struct { 70 u8 type; 71 u8 len; 72 u16 slot_id; 73 u8 bus_id; 74 u8 dev_num; 75 u8 slot_num; 76 u8 slot_attr[2]; 77 u8 attn; 78 u8 status[2]; 79 u8 sun; 80 u8 res[3]; 81 } slot; 82 struct { 83 u8 type; 84 u8 len; 85 } generic; 86 }; 87 88 /* struct notification - keeps info about the device 89 * that cause the ACPI notification event 90 */ 91 struct notification { 92 struct acpi_device *device; 93 u8 event; 94 }; 95 96 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); 97 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); 98 static void ibm_handle_events(acpi_handle handle, u32 event, void *context); 99 static int ibm_get_table_from_acpi(char **bufp); 100 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 101 struct bin_attribute *bin_attr, 102 char *buffer, loff_t pos, size_t size); 103 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 104 u32 lvl, void *context, void **rv); 105 static int __init ibm_acpiphp_init(void); 106 static void __exit ibm_acpiphp_exit(void); 107 108 static acpi_handle ibm_acpi_handle; 109 static struct notification ibm_note; 110 static struct bin_attribute ibm_apci_table_attr __ro_after_init = { 111 .attr = { 112 .name = "apci_table", 113 .mode = S_IRUGO, 114 }, 115 .read = ibm_read_apci_table, 116 .write = NULL, 117 }; 118 static struct acpiphp_attention_info ibm_attention_info = 119 { 120 .set_attn = ibm_set_attention_status, 121 .get_attn = ibm_get_attention_status, 122 .owner = THIS_MODULE, 123 }; 124 125 /** 126 * ibm_slot_from_id - workaround for bad ibm hardware 127 * @id: the slot number that linux refers to the slot by 128 * 129 * Description: This method returns the aCPI slot descriptor 130 * corresponding to the Linux slot number. This descriptor 131 * has info about the aPCI slot id and attention status. 132 * This descriptor must be freed using kfree when done. 133 */ 134 static union apci_descriptor *ibm_slot_from_id(int id) 135 { 136 int ind = 0, size; 137 union apci_descriptor *ret = NULL, *des; 138 char *table; 139 140 size = ibm_get_table_from_acpi(&table); 141 if (size < 0) 142 return NULL; 143 des = (union apci_descriptor *)table; 144 if (memcmp(des->header.sig, "aPCI", 4) != 0) 145 goto ibm_slot_done; 146 147 des = (union apci_descriptor *)&table[ind += des->header.len]; 148 while (ind < size && (des->generic.type != 0x82 || 149 des->slot.slot_num != id)) { 150 des = (union apci_descriptor *)&table[ind += des->generic.len]; 151 } 152 153 if (ind < size && des->slot.slot_num == id) 154 ret = des; 155 156 ibm_slot_done: 157 if (ret) { 158 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); 159 if (ret) 160 memcpy(ret, des, sizeof(union apci_descriptor)); 161 } 162 kfree(table); 163 return ret; 164 } 165 166 /** 167 * ibm_set_attention_status - callback method to set the attention LED 168 * @slot: the hotplug_slot to work with 169 * @status: what to set the LED to (0 or 1) 170 * 171 * Description: This method is registered with the acpiphp module as a 172 * callback to do the device specific task of setting the LED status. 173 */ 174 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 175 { 176 union acpi_object args[2]; 177 struct acpi_object_list params = { .pointer = args, .count = 2 }; 178 acpi_status stat; 179 unsigned long long rc; 180 union apci_descriptor *ibm_slot; 181 int id = hpslot_to_sun(slot); 182 183 ibm_slot = ibm_slot_from_id(id); 184 if (!ibm_slot) { 185 pr_err("APLS null ACPI descriptor for slot %d\n", id); 186 return -ENODEV; 187 } 188 189 pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__, 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 pr_err("APLS evaluation failed: 0x%08x\n", stat); 203 return -ENODEV; 204 } else if (!rc) { 205 pr_err("APLS method failed: 0x%08llx\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 int id = hpslot_to_sun(slot); 227 228 ibm_slot = ibm_slot_from_id(id); 229 if (!ibm_slot) { 230 pr_err("APLS null ACPI descriptor for slot %d\n", id); 231 return -ENODEV; 232 } 233 234 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 235 *status = 1; 236 else 237 *status = 0; 238 239 pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__, 240 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 241 *status); 242 243 kfree(ibm_slot); 244 return 0; 245 } 246 247 /** 248 * ibm_handle_events - listens for ACPI events for the IBM37D0 device 249 * @handle: an ACPI handle to the device that caused the event 250 * @event: the event info (device specific) 251 * @context: passed context (our notification struct) 252 * 253 * Description: This method is registered as a callback with the ACPI 254 * subsystem it is called when this device has an event to notify the OS of. 255 * 256 * The events actually come from the device as two events that get 257 * synthesized into one event with data by this function. The event 258 * ID comes first and then the slot number that caused it. We report 259 * this as one event to the OS. 260 * 261 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will 262 * only re-enable the interrupt that causes this event AFTER this method 263 * has returned, thereby enforcing serial access for the notification struct. 264 */ 265 static void ibm_handle_events(acpi_handle handle, u32 event, void *context) 266 { 267 u8 detail = event & 0x0f; 268 u8 subevent = event & 0xf0; 269 struct notification *note = context; 270 271 pr_debug("%s: Received notification %02x\n", __func__, event); 272 273 if (subevent == 0x80) { 274 pr_debug("%s: generating bus event\n", __func__); 275 acpi_bus_generate_netlink_event(note->device->pnp.device_class, 276 dev_name(¬e->device->dev), 277 note->event, detail); 278 } else 279 note->event = event; 280 } 281 282 /** 283 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI 284 * @bufp: address to pointer to allocate for the table 285 * 286 * Description: This method reads the APLS buffer in from ACPI and 287 * stores the "stripped" table into a single buffer 288 * it allocates and passes the address back in bufp. 289 * 290 * If NULL is passed in as buffer, this method only calculates 291 * the size of the table and returns that without filling 292 * in the buffer. 293 * 294 * Returns < 0 on error or the size of the table on success. 295 */ 296 static int ibm_get_table_from_acpi(char **bufp) 297 { 298 union acpi_object *package; 299 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 300 acpi_status status; 301 char *lbuf = NULL; 302 int i, size = -EIO; 303 304 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); 305 if (ACPI_FAILURE(status)) { 306 pr_err("%s: APCI evaluation failed\n", __func__); 307 return -ENODEV; 308 } 309 310 package = (union acpi_object *) buffer.pointer; 311 if (!(package) || 312 (package->type != ACPI_TYPE_PACKAGE) || 313 !(package->package.elements)) { 314 pr_err("%s: Invalid APCI object\n", __func__); 315 goto read_table_done; 316 } 317 318 for (size = 0, i = 0; i < package->package.count; i++) { 319 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { 320 pr_err("%s: Invalid APCI element %d\n", __func__, i); 321 goto read_table_done; 322 } 323 size += package->package.elements[i].buffer.length; 324 } 325 326 if (bufp == NULL) 327 goto read_table_done; 328 329 lbuf = kzalloc(size, GFP_KERNEL); 330 pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", 331 __func__, package->package.count, size, lbuf); 332 333 if (lbuf) { 334 *bufp = lbuf; 335 } else { 336 size = -ENOMEM; 337 goto read_table_done; 338 } 339 340 size = 0; 341 for (i = 0; i < package->package.count; i++) { 342 memcpy(&lbuf[size], 343 package->package.elements[i].buffer.pointer, 344 package->package.elements[i].buffer.length); 345 size += package->package.elements[i].buffer.length; 346 } 347 348 read_table_done: 349 kfree(buffer.pointer); 350 return size; 351 } 352 353 /** 354 * ibm_read_apci_table - callback for the sysfs apci_table file 355 * @filp: the open sysfs file 356 * @kobj: the kobject this binary attribute is a part of 357 * @bin_attr: struct bin_attribute for this file 358 * @buffer: the kernel space buffer to fill 359 * @pos: the offset into the file 360 * @size: the number of bytes requested 361 * 362 * Description: Gets registered with sysfs as the reader callback 363 * to be executed when /sys/bus/pci/slots/apci_table gets read. 364 * 365 * Since we don't get notified on open and close for this file, 366 * things get really tricky here... 367 * our solution is to only allow reading the table in all at once. 368 */ 369 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 370 struct bin_attribute *bin_attr, 371 char *buffer, loff_t pos, size_t size) 372 { 373 int bytes_read = -EINVAL; 374 char *table = NULL; 375 376 pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); 377 378 if (pos == 0) { 379 bytes_read = ibm_get_table_from_acpi(&table); 380 if (bytes_read > 0 && bytes_read <= size) 381 memcpy(buffer, table, bytes_read); 382 kfree(table); 383 } 384 return bytes_read; 385 } 386 387 /** 388 * ibm_find_acpi_device - callback to find our ACPI device 389 * @handle: the ACPI handle of the device we are inspecting 390 * @lvl: depth into the namespace tree 391 * @context: a pointer to our handle to fill when we find the device 392 * @rv: a return value to fill if desired 393 * 394 * Description: Used as a callback when calling acpi_walk_namespace 395 * to find our device. When this method returns non-zero 396 * acpi_walk_namespace quits its search and returns our value. 397 */ 398 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 399 u32 lvl, void *context, void **rv) 400 { 401 acpi_handle *phandle = (acpi_handle *)context; 402 acpi_status status; 403 struct acpi_device_info *info; 404 int retval = 0; 405 406 status = acpi_get_object_info(handle, &info); 407 if (ACPI_FAILURE(status)) { 408 pr_err("%s: Failed to get device information status=0x%x\n", 409 __func__, status); 410 return retval; 411 } 412 413 if (info->current_status && (info->valid & ACPI_VALID_HID) && 414 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || 415 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { 416 pr_debug("found hardware: %s, handle: %p\n", 417 info->hardware_id.string, handle); 418 *phandle = handle; 419 /* returning non-zero causes the search to stop 420 * and returns this value to the caller of 421 * acpi_walk_namespace, but it also causes some warnings 422 * in the acpi debug code to print... 423 */ 424 retval = FOUND_APCI; 425 } 426 kfree(info); 427 return retval; 428 } 429 430 static int __init ibm_acpiphp_init(void) 431 { 432 int retval = 0; 433 acpi_status status; 434 struct acpi_device *device; 435 struct kobject *sysdir = &pci_slots_kset->kobj; 436 437 pr_debug("%s\n", __func__); 438 439 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 440 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, 441 &ibm_acpi_handle, NULL) != FOUND_APCI) { 442 pr_err("%s: acpi_walk_namespace failed\n", __func__); 443 retval = -ENODEV; 444 goto init_return; 445 } 446 pr_debug("%s: found IBM aPCI device\n", __func__); 447 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 448 pr_err("%s: acpi_bus_get_device failed\n", __func__); 449 retval = -ENODEV; 450 goto init_return; 451 } 452 if (acpiphp_register_attention(&ibm_attention_info)) { 453 retval = -ENODEV; 454 goto init_return; 455 } 456 457 ibm_note.device = device; 458 status = acpi_install_notify_handler(ibm_acpi_handle, 459 ACPI_DEVICE_NOTIFY, ibm_handle_events, 460 &ibm_note); 461 if (ACPI_FAILURE(status)) { 462 pr_err("%s: Failed to register notification handler\n", 463 __func__); 464 retval = -EBUSY; 465 goto init_cleanup; 466 } 467 468 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 469 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 470 471 return retval; 472 473 init_cleanup: 474 acpiphp_unregister_attention(&ibm_attention_info); 475 init_return: 476 return retval; 477 } 478 479 static void __exit ibm_acpiphp_exit(void) 480 { 481 acpi_status status; 482 struct kobject *sysdir = &pci_slots_kset->kobj; 483 484 pr_debug("%s\n", __func__); 485 486 if (acpiphp_unregister_attention(&ibm_attention_info)) 487 pr_err("%s: attention info deregistration failed", __func__); 488 489 status = acpi_remove_notify_handler( 490 ibm_acpi_handle, 491 ACPI_DEVICE_NOTIFY, 492 ibm_handle_events); 493 if (ACPI_FAILURE(status)) 494 pr_err("%s: Notification handler removal failed\n", __func__); 495 /* remove the /sys entries */ 496 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); 497 } 498 499 module_init(ibm_acpiphp_init); 500 module_exit(ibm_acpiphp_exit); 501