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