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 <asm/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 = { 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 des = (union apci_descriptor *)table; 142 if (memcmp(des->header.sig, "aPCI", 4) != 0) 143 goto ibm_slot_done; 144 145 des = (union apci_descriptor *)&table[ind += des->header.len]; 146 while (ind < size && (des->generic.type != 0x82 || 147 des->slot.slot_num != id)) { 148 des = (union apci_descriptor *)&table[ind += des->generic.len]; 149 } 150 151 if (ind < size && des->slot.slot_num == id) 152 ret = des; 153 154 ibm_slot_done: 155 if (ret) { 156 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); 157 if (ret) 158 memcpy(ret, des, sizeof(union apci_descriptor)); 159 } 160 kfree(table); 161 return ret; 162 } 163 164 /** 165 * ibm_set_attention_status - callback method to set the attention LED 166 * @slot: the hotplug_slot to work with 167 * @status: what to set the LED to (0 or 1) 168 * 169 * Description: This method is registered with the acpiphp module as a 170 * callback to do the device specific task of setting the LED status. 171 */ 172 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 173 { 174 union acpi_object args[2]; 175 struct acpi_object_list params = { .pointer = args, .count = 2 }; 176 acpi_status stat; 177 unsigned long long rc; 178 union apci_descriptor *ibm_slot; 179 int id = hpslot_to_sun(slot); 180 181 ibm_slot = ibm_slot_from_id(id); 182 if (!ibm_slot) { 183 pr_err("APLS null ACPI descriptor for slot %d\n", id); 184 return -ENODEV; 185 } 186 187 pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__, 188 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 189 (status ? 1 : 0)); 190 191 args[0].type = ACPI_TYPE_INTEGER; 192 args[0].integer.value = ibm_slot->slot.slot_id; 193 args[1].type = ACPI_TYPE_INTEGER; 194 args[1].integer.value = (status) ? 1 : 0; 195 196 kfree(ibm_slot); 197 198 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); 199 if (ACPI_FAILURE(stat)) { 200 pr_err("APLS evaluation failed: 0x%08x\n", stat); 201 return -ENODEV; 202 } else if (!rc) { 203 pr_err("APLS method failed: 0x%08llx\n", rc); 204 return -ERANGE; 205 } 206 return 0; 207 } 208 209 /** 210 * ibm_get_attention_status - callback method to get attention LED status 211 * @slot: the hotplug_slot to work with 212 * @status: returns what the LED is set to (0 or 1) 213 * 214 * Description: This method is registered with the acpiphp module as a 215 * callback to do the device specific task of getting the LED status. 216 * 217 * Because there is no direct method of getting the LED status directly 218 * from an ACPI call, we read the aPCI table and parse out our 219 * slot descriptor to read the status from that. 220 */ 221 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) 222 { 223 union apci_descriptor *ibm_slot; 224 int id = hpslot_to_sun(slot); 225 226 ibm_slot = ibm_slot_from_id(id); 227 if (!ibm_slot) { 228 pr_err("APLS null ACPI descriptor for slot %d\n", id); 229 return -ENODEV; 230 } 231 232 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 233 *status = 1; 234 else 235 *status = 0; 236 237 pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__, 238 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 239 *status); 240 241 kfree(ibm_slot); 242 return 0; 243 } 244 245 /** 246 * ibm_handle_events - listens for ACPI events for the IBM37D0 device 247 * @handle: an ACPI handle to the device that caused the event 248 * @event: the event info (device specific) 249 * @context: passed context (our notification struct) 250 * 251 * Description: This method is registered as a callback with the ACPI 252 * subsystem it is called when this device has an event to notify the OS of. 253 * 254 * The events actually come from the device as two events that get 255 * synthesized into one event with data by this function. The event 256 * ID comes first and then the slot number that caused it. We report 257 * this as one event to the OS. 258 * 259 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will 260 * only re-enable the interrupt that causes this event AFTER this method 261 * has returned, thereby enforcing serial access for the notification struct. 262 */ 263 static void ibm_handle_events(acpi_handle handle, u32 event, void *context) 264 { 265 u8 detail = event & 0x0f; 266 u8 subevent = event & 0xf0; 267 struct notification *note = context; 268 269 pr_debug("%s: Received notification %02x\n", __func__, event); 270 271 if (subevent == 0x80) { 272 pr_debug("%s: generating bus event\n", __func__); 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 pr_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 pr_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 pr_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 pr_debug("%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 * @filp: the open sysfs file 354 * @kobj: the kobject this binary attribute is a part of 355 * @bin_attr: struct bin_attribute for this file 356 * @buffer: the kernel space buffer to fill 357 * @pos: the offset into the file 358 * @size: the number of bytes requested 359 * 360 * Description: Gets registered with sysfs as the reader callback 361 * to be executed when /sys/bus/pci/slots/apci_table gets read. 362 * 363 * Since we don't get notified on open and close for this file, 364 * things get really tricky here... 365 * our solution is to only allow reading the table in all at once. 366 */ 367 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 368 struct bin_attribute *bin_attr, 369 char *buffer, loff_t pos, size_t size) 370 { 371 int bytes_read = -EINVAL; 372 char *table = NULL; 373 374 pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); 375 376 if (pos == 0) { 377 bytes_read = ibm_get_table_from_acpi(&table); 378 if (bytes_read > 0 && bytes_read <= size) 379 memcpy(buffer, table, bytes_read); 380 kfree(table); 381 } 382 return bytes_read; 383 } 384 385 /** 386 * ibm_find_acpi_device - callback to find our ACPI device 387 * @handle: the ACPI handle of the device we are inspecting 388 * @lvl: depth into the namespace tree 389 * @context: a pointer to our handle to fill when we find the device 390 * @rv: a return value to fill if desired 391 * 392 * Description: Used as a callback when calling acpi_walk_namespace 393 * to find our device. When this method returns non-zero 394 * acpi_walk_namespace quits its search and returns our value. 395 */ 396 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 397 u32 lvl, void *context, void **rv) 398 { 399 acpi_handle *phandle = (acpi_handle *)context; 400 acpi_status status; 401 struct acpi_device_info *info; 402 int retval = 0; 403 404 status = acpi_get_object_info(handle, &info); 405 if (ACPI_FAILURE(status)) { 406 pr_err("%s: Failed to get device information status=0x%x\n", 407 __func__, status); 408 return retval; 409 } 410 411 if (info->current_status && (info->valid & ACPI_VALID_HID) && 412 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || 413 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { 414 pr_debug("found hardware: %s, handle: %p\n", 415 info->hardware_id.string, handle); 416 *phandle = handle; 417 /* returning non-zero causes the search to stop 418 * and returns this value to the caller of 419 * acpi_walk_namespace, but it also causes some warnings 420 * in the acpi debug code to print... 421 */ 422 retval = FOUND_APCI; 423 } 424 kfree(info); 425 return retval; 426 } 427 428 static int __init ibm_acpiphp_init(void) 429 { 430 int retval = 0; 431 acpi_status status; 432 struct acpi_device *device; 433 struct kobject *sysdir = &pci_slots_kset->kobj; 434 435 pr_debug("%s\n", __func__); 436 437 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 438 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, 439 &ibm_acpi_handle, NULL) != FOUND_APCI) { 440 pr_err("%s: acpi_walk_namespace failed\n", __func__); 441 retval = -ENODEV; 442 goto init_return; 443 } 444 pr_debug("%s: found IBM aPCI device\n", __func__); 445 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 446 pr_err("%s: acpi_bus_get_device failed\n", __func__); 447 retval = -ENODEV; 448 goto init_return; 449 } 450 if (acpiphp_register_attention(&ibm_attention_info)) { 451 retval = -ENODEV; 452 goto init_return; 453 } 454 455 ibm_note.device = device; 456 status = acpi_install_notify_handler(ibm_acpi_handle, 457 ACPI_DEVICE_NOTIFY, ibm_handle_events, 458 &ibm_note); 459 if (ACPI_FAILURE(status)) { 460 pr_err("%s: Failed to register notification handler\n", 461 __func__); 462 retval = -EBUSY; 463 goto init_cleanup; 464 } 465 466 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 467 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 468 469 return retval; 470 471 init_cleanup: 472 acpiphp_unregister_attention(&ibm_attention_info); 473 init_return: 474 return retval; 475 } 476 477 static void __exit ibm_acpiphp_exit(void) 478 { 479 acpi_status status; 480 struct kobject *sysdir = &pci_slots_kset->kobj; 481 482 pr_debug("%s\n", __func__); 483 484 if (acpiphp_unregister_attention(&ibm_attention_info)) 485 pr_err("%s: attention info deregistration failed", __func__); 486 487 status = acpi_remove_notify_handler( 488 ibm_acpi_handle, 489 ACPI_DEVICE_NOTIFY, 490 ibm_handle_events); 491 if (ACPI_FAILURE(status)) 492 pr_err("%s: Notification handler removal failed\n", __func__); 493 /* remove the /sys entries */ 494 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); 495 } 496 497 module_init(ibm_acpiphp_init); 498 module_exit(ibm_acpiphp_exit); 499