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 memcpy(ret, des, sizeof(union apci_descriptor)); 158 } 159 kfree(table); 160 return ret; 161 } 162 163 /** 164 * ibm_set_attention_status - callback method to set the attention LED 165 * @slot: the hotplug_slot to work with 166 * @status: what to set the LED to (0 or 1) 167 * 168 * Description: This method is registered with the acpiphp module as a 169 * callback to do the device specific task of setting the LED status. 170 */ 171 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 172 { 173 union acpi_object args[2]; 174 struct acpi_object_list params = { .pointer = args, .count = 2 }; 175 acpi_status stat; 176 unsigned long long rc; 177 union apci_descriptor *ibm_slot; 178 179 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 180 181 pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__, 182 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 183 (status ? 1 : 0)); 184 185 args[0].type = ACPI_TYPE_INTEGER; 186 args[0].integer.value = ibm_slot->slot.slot_id; 187 args[1].type = ACPI_TYPE_INTEGER; 188 args[1].integer.value = (status) ? 1 : 0; 189 190 kfree(ibm_slot); 191 192 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); 193 if (ACPI_FAILURE(stat)) { 194 pr_err("APLS evaluation failed: 0x%08x\n", stat); 195 return -ENODEV; 196 } else if (!rc) { 197 pr_err("APLS method failed: 0x%08llx\n", rc); 198 return -ERANGE; 199 } 200 return 0; 201 } 202 203 /** 204 * ibm_get_attention_status - callback method to get attention LED status 205 * @slot: the hotplug_slot to work with 206 * @status: returns what the LED is set to (0 or 1) 207 * 208 * Description: This method is registered with the acpiphp module as a 209 * callback to do the device specific task of getting the LED status. 210 * 211 * Because there is no direct method of getting the LED status directly 212 * from an ACPI call, we read the aPCI table and parse out our 213 * slot descriptor to read the status from that. 214 */ 215 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) 216 { 217 union apci_descriptor *ibm_slot; 218 219 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 220 221 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 222 *status = 1; 223 else 224 *status = 0; 225 226 pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__, 227 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 228 *status); 229 230 kfree(ibm_slot); 231 return 0; 232 } 233 234 /** 235 * ibm_handle_events - listens for ACPI events for the IBM37D0 device 236 * @handle: an ACPI handle to the device that caused the event 237 * @event: the event info (device specific) 238 * @context: passed context (our notification struct) 239 * 240 * Description: This method is registered as a callback with the ACPI 241 * subsystem it is called when this device has an event to notify the OS of. 242 * 243 * The events actually come from the device as two events that get 244 * synthesized into one event with data by this function. The event 245 * ID comes first and then the slot number that caused it. We report 246 * this as one event to the OS. 247 * 248 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will 249 * only re-enable the interrupt that causes this event AFTER this method 250 * has returned, thereby enforcing serial access for the notification struct. 251 */ 252 static void ibm_handle_events(acpi_handle handle, u32 event, void *context) 253 { 254 u8 detail = event & 0x0f; 255 u8 subevent = event & 0xf0; 256 struct notification *note = context; 257 258 pr_debug("%s: Received notification %02x\n", __func__, event); 259 260 if (subevent == 0x80) { 261 pr_debug("%s: generating bus event\n", __func__); 262 acpi_bus_generate_netlink_event(note->device->pnp.device_class, 263 dev_name(¬e->device->dev), 264 note->event, detail); 265 } else 266 note->event = event; 267 } 268 269 /** 270 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI 271 * @bufp: address to pointer to allocate for the table 272 * 273 * Description: This method reads the APLS buffer in from ACPI and 274 * stores the "stripped" table into a single buffer 275 * it allocates and passes the address back in bufp. 276 * 277 * If NULL is passed in as buffer, this method only calculates 278 * the size of the table and returns that without filling 279 * in the buffer. 280 * 281 * Returns < 0 on error or the size of the table on success. 282 */ 283 static int ibm_get_table_from_acpi(char **bufp) 284 { 285 union acpi_object *package; 286 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 287 acpi_status status; 288 char *lbuf = NULL; 289 int i, size = -EIO; 290 291 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); 292 if (ACPI_FAILURE(status)) { 293 pr_err("%s: APCI evaluation failed\n", __func__); 294 return -ENODEV; 295 } 296 297 package = (union acpi_object *) buffer.pointer; 298 if (!(package) || 299 (package->type != ACPI_TYPE_PACKAGE) || 300 !(package->package.elements)) { 301 pr_err("%s: Invalid APCI object\n", __func__); 302 goto read_table_done; 303 } 304 305 for (size = 0, i = 0; i < package->package.count; i++) { 306 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { 307 pr_err("%s: Invalid APCI element %d\n", __func__, i); 308 goto read_table_done; 309 } 310 size += package->package.elements[i].buffer.length; 311 } 312 313 if (bufp == NULL) 314 goto read_table_done; 315 316 lbuf = kzalloc(size, GFP_KERNEL); 317 pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", 318 __func__, package->package.count, size, lbuf); 319 320 if (lbuf) { 321 *bufp = lbuf; 322 } else { 323 size = -ENOMEM; 324 goto read_table_done; 325 } 326 327 size = 0; 328 for (i=0; i<package->package.count; i++) { 329 memcpy(&lbuf[size], 330 package->package.elements[i].buffer.pointer, 331 package->package.elements[i].buffer.length); 332 size += package->package.elements[i].buffer.length; 333 } 334 335 read_table_done: 336 kfree(buffer.pointer); 337 return size; 338 } 339 340 /** 341 * ibm_read_apci_table - callback for the sysfs apci_table file 342 * @filp: the open sysfs file 343 * @kobj: the kobject this binary attribute is a part of 344 * @bin_attr: struct bin_attribute for this file 345 * @buffer: the kernel space buffer to fill 346 * @pos: the offset into the file 347 * @size: the number of bytes requested 348 * 349 * Description: Gets registered with sysfs as the reader callback 350 * to be executed when /sys/bus/pci/slots/apci_table gets read. 351 * 352 * Since we don't get notified on open and close for this file, 353 * things get really tricky here... 354 * our solution is to only allow reading the table in all at once. 355 */ 356 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 357 struct bin_attribute *bin_attr, 358 char *buffer, loff_t pos, size_t size) 359 { 360 int bytes_read = -EINVAL; 361 char *table = NULL; 362 363 pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); 364 365 if (pos == 0) { 366 bytes_read = ibm_get_table_from_acpi(&table); 367 if (bytes_read > 0 && bytes_read <= size) 368 memcpy(buffer, table, bytes_read); 369 kfree(table); 370 } 371 return bytes_read; 372 } 373 374 /** 375 * ibm_find_acpi_device - callback to find our ACPI device 376 * @handle: the ACPI handle of the device we are inspecting 377 * @lvl: depth into the namespace tree 378 * @context: a pointer to our handle to fill when we find the device 379 * @rv: a return value to fill if desired 380 * 381 * Description: Used as a callback when calling acpi_walk_namespace 382 * to find our device. When this method returns non-zero 383 * acpi_walk_namespace quits its search and returns our value. 384 */ 385 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 386 u32 lvl, void *context, void **rv) 387 { 388 acpi_handle *phandle = (acpi_handle *)context; 389 acpi_status status; 390 struct acpi_device_info *info; 391 int retval = 0; 392 393 status = acpi_get_object_info(handle, &info); 394 if (ACPI_FAILURE(status)) { 395 pr_err("%s: Failed to get device information status=0x%x\n", 396 __func__, status); 397 return retval; 398 } 399 400 if (info->current_status && (info->valid & ACPI_VALID_HID) && 401 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || 402 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { 403 pr_debug("found hardware: %s, handle: %p\n", 404 info->hardware_id.string, handle); 405 *phandle = handle; 406 /* returning non-zero causes the search to stop 407 * and returns this value to the caller of 408 * acpi_walk_namespace, but it also causes some warnings 409 * in the acpi debug code to print... 410 */ 411 retval = FOUND_APCI; 412 } 413 kfree(info); 414 return retval; 415 } 416 417 static int __init ibm_acpiphp_init(void) 418 { 419 int retval = 0; 420 acpi_status status; 421 struct acpi_device *device; 422 struct kobject *sysdir = &pci_slots_kset->kobj; 423 424 pr_debug("%s\n", __func__); 425 426 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 427 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, 428 &ibm_acpi_handle, NULL) != FOUND_APCI) { 429 pr_err("%s: acpi_walk_namespace failed\n", __func__); 430 retval = -ENODEV; 431 goto init_return; 432 } 433 pr_debug("%s: found IBM aPCI device\n", __func__); 434 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 435 pr_err("%s: acpi_bus_get_device failed\n", __func__); 436 retval = -ENODEV; 437 goto init_return; 438 } 439 if (acpiphp_register_attention(&ibm_attention_info)) { 440 retval = -ENODEV; 441 goto init_return; 442 } 443 444 ibm_note.device = device; 445 status = acpi_install_notify_handler(ibm_acpi_handle, 446 ACPI_DEVICE_NOTIFY, ibm_handle_events, 447 &ibm_note); 448 if (ACPI_FAILURE(status)) { 449 pr_err("%s: Failed to register notification handler\n", 450 __func__); 451 retval = -EBUSY; 452 goto init_cleanup; 453 } 454 455 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 456 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 457 458 return retval; 459 460 init_cleanup: 461 acpiphp_unregister_attention(&ibm_attention_info); 462 init_return: 463 return retval; 464 } 465 466 static void __exit ibm_acpiphp_exit(void) 467 { 468 acpi_status status; 469 struct kobject *sysdir = &pci_slots_kset->kobj; 470 471 pr_debug("%s\n", __func__); 472 473 if (acpiphp_unregister_attention(&ibm_attention_info)) 474 pr_err("%s: attention info deregistration failed", __func__); 475 476 status = acpi_remove_notify_handler( 477 ibm_acpi_handle, 478 ACPI_DEVICE_NOTIFY, 479 ibm_handle_events); 480 if (ACPI_FAILURE(status)) 481 pr_err("%s: Notification handler removal failed\n", __func__); 482 /* remove the /sys entries */ 483 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); 484 } 485 486 module_init(ibm_acpiphp_init); 487 module_exit(ibm_acpiphp_exit); 488