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/slab.h> 30#include <linux/module.h> 31#include <linux/kernel.h> 32#include <acpi/acpi_bus.h> 33#include <linux/sysfs.h> 34#include <linux/kobject.h> 35#include <asm/uaccess.h> 36#include <linux/moduleparam.h> 37#include <linux/pci.h> 38 39#include "acpiphp.h" 40#include "../pci.h" 41 42#define DRIVER_VERSION "1.0.1" 43#define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" 44#define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" 45 46static bool debug; 47 48MODULE_AUTHOR(DRIVER_AUTHOR); 49MODULE_DESCRIPTION(DRIVER_DESC); 50MODULE_LICENSE("GPL"); 51MODULE_VERSION(DRIVER_VERSION); 52module_param(debug, bool, 0644); 53MODULE_PARM_DESC(debug, " Debugging mode enabled or not"); 54#define MY_NAME "acpiphp_ibm" 55 56#undef dbg 57#define dbg(format, arg...) \ 58do { \ 59 if (debug) \ 60 printk(KERN_DEBUG "%s: " format, \ 61 MY_NAME , ## arg); \ 62} while (0) 63 64#define FOUND_APCI 0x61504349 65/* these are the names for the IBM ACPI pseudo-device */ 66#define IBM_HARDWARE_ID1 "IBM37D0" 67#define IBM_HARDWARE_ID2 "IBM37D4" 68 69#define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun) 70 71/* union apci_descriptor - allows access to the 72 * various device descriptors that are embedded in the 73 * aPCI table 74 */ 75union apci_descriptor { 76 struct { 77 char sig[4]; 78 u8 len; 79 } header; 80 struct { 81 u8 type; 82 u8 len; 83 u16 slot_id; 84 u8 bus_id; 85 u8 dev_num; 86 u8 slot_num; 87 u8 slot_attr[2]; 88 u8 attn; 89 u8 status[2]; 90 u8 sun; 91 u8 res[3]; 92 } slot; 93 struct { 94 u8 type; 95 u8 len; 96 } generic; 97}; 98 99/* struct notification - keeps info about the device 100 * that cause the ACPI notification event 101 */ 102struct notification { 103 struct acpi_device *device; 104 u8 event; 105}; 106 107static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); 108static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); 109static void ibm_handle_events(acpi_handle handle, u32 event, void *context); 110static int ibm_get_table_from_acpi(char **bufp); 111static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 112 struct bin_attribute *bin_attr, 113 char *buffer, loff_t pos, size_t size); 114static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 115 u32 lvl, void *context, void **rv); 116static int __init ibm_acpiphp_init(void); 117static void __exit ibm_acpiphp_exit(void); 118 119static acpi_handle ibm_acpi_handle; 120static struct notification ibm_note; 121static struct bin_attribute ibm_apci_table_attr = { 122 .attr = { 123 .name = "apci_table", 124 .mode = S_IRUGO, 125 }, 126 .read = ibm_read_apci_table, 127 .write = NULL, 128}; 129static struct acpiphp_attention_info ibm_attention_info = 130{ 131 .set_attn = ibm_set_attention_status, 132 .get_attn = ibm_get_attention_status, 133 .owner = THIS_MODULE, 134}; 135 136/** 137 * ibm_slot_from_id - workaround for bad ibm hardware 138 * @id: the slot number that linux refers to the slot by 139 * 140 * Description: This method returns the aCPI slot descriptor 141 * corresponding to the Linux slot number. This descriptor 142 * has info about the aPCI slot id and attention status. 143 * This descriptor must be freed using kfree when done. 144 */ 145static union apci_descriptor *ibm_slot_from_id(int id) 146{ 147 int ind = 0, size; 148 union apci_descriptor *ret = NULL, *des; 149 char *table; 150 151 size = ibm_get_table_from_acpi(&table); 152 des = (union apci_descriptor *)table; 153 if (memcmp(des->header.sig, "aPCI", 4) != 0) 154 goto ibm_slot_done; 155 156 des = (union apci_descriptor *)&table[ind += des->header.len]; 157 while (ind < size && (des->generic.type != 0x82 || 158 des->slot.slot_num != id)) { 159 des = (union apci_descriptor *)&table[ind += des->generic.len]; 160 } 161 162 if (ind < size && des->slot.slot_num == id) 163 ret = des; 164 165ibm_slot_done: 166 if (ret) { 167 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); 168 memcpy(ret, des, sizeof(union apci_descriptor)); 169 } 170 kfree(table); 171 return ret; 172} 173 174/** 175 * ibm_set_attention_status - callback method to set the attention LED 176 * @slot: the hotplug_slot to work with 177 * @status: what to set the LED to (0 or 1) 178 * 179 * Description: This method is registered with the acpiphp module as a 180 * callback to do the device specific task of setting the LED status. 181 */ 182static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 183{ 184 union acpi_object args[2]; 185 struct acpi_object_list params = { .pointer = args, .count = 2 }; 186 acpi_status stat; 187 unsigned long long rc; 188 union apci_descriptor *ibm_slot; 189 190 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 191 192 dbg("%s: set slot %d (%d) attention status to %d\n", __func__, 193 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 194 (status ? 1 : 0)); 195 196 args[0].type = ACPI_TYPE_INTEGER; 197 args[0].integer.value = ibm_slot->slot.slot_id; 198 args[1].type = ACPI_TYPE_INTEGER; 199 args[1].integer.value = (status) ? 1 : 0; 200 201 kfree(ibm_slot); 202 203 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); 204 if (ACPI_FAILURE(stat)) { 205 err("APLS evaluation failed: 0x%08x\n", stat); 206 return -ENODEV; 207 } else if (!rc) { 208 err("APLS method failed: 0x%08llx\n", rc); 209 return -ERANGE; 210 } 211 return 0; 212} 213 214/** 215 * ibm_get_attention_status - callback method to get attention LED status 216 * @slot: the hotplug_slot to work with 217 * @status: returns what the LED is set to (0 or 1) 218 * 219 * Description: This method is registered with the acpiphp module as a 220 * callback to do the device specific task of getting the LED status. 221 * 222 * Because there is no direct method of getting the LED status directly 223 * from an ACPI call, we read the aPCI table and parse out our 224 * slot descriptor to read the status from that. 225 */ 226static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) 227{ 228 union apci_descriptor *ibm_slot; 229 230 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); 231 232 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 233 *status = 1; 234 else 235 *status = 0; 236 237 dbg("%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 */ 263static 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 dbg("%s: Received notification %02x\n", __func__, event); 270 271 if (subevent == 0x80) { 272 dbg("%s: generationg bus event\n", __func__); 273 acpi_bus_generate_proc_event(note->device, note->event, detail); 274 acpi_bus_generate_netlink_event(note->device->pnp.device_class, 275 dev_name(¬e->device->dev), 276 note->event, detail); 277 } else 278 note->event = event; 279} 280 281/** 282 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI 283 * @bufp: address to pointer to allocate for the table 284 * 285 * Description: This method reads the APLS buffer in from ACPI and 286 * stores the "stripped" table into a single buffer 287 * it allocates and passes the address back in bufp. 288 * 289 * If NULL is passed in as buffer, this method only calculates 290 * the size of the table and returns that without filling 291 * in the buffer. 292 * 293 * Returns < 0 on error or the size of the table on success. 294 */ 295static int ibm_get_table_from_acpi(char **bufp) 296{ 297 union acpi_object *package; 298 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 299 acpi_status status; 300 char *lbuf = NULL; 301 int i, size = -EIO; 302 303 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); 304 if (ACPI_FAILURE(status)) { 305 err("%s: APCI evaluation failed\n", __func__); 306 return -ENODEV; 307 } 308 309 package = (union acpi_object *) buffer.pointer; 310 if (!(package) || 311 (package->type != ACPI_TYPE_PACKAGE) || 312 !(package->package.elements)) { 313 err("%s: Invalid APCI object\n", __func__); 314 goto read_table_done; 315 } 316 317 for(size = 0, i = 0; i < package->package.count; i++) { 318 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { 319 err("%s: Invalid APCI element %d\n", __func__, i); 320 goto read_table_done; 321 } 322 size += package->package.elements[i].buffer.length; 323 } 324 325 if (bufp == NULL) 326 goto read_table_done; 327 328 lbuf = kzalloc(size, GFP_KERNEL); 329 dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", 330 __func__, package->package.count, size, lbuf); 331 332 if (lbuf) { 333 *bufp = lbuf; 334 } else { 335 size = -ENOMEM; 336 goto read_table_done; 337 } 338 339 size = 0; 340 for (i=0; i<package->package.count; i++) { 341 memcpy(&lbuf[size], 342 package->package.elements[i].buffer.pointer, 343 package->package.elements[i].buffer.length); 344 size += package->package.elements[i].buffer.length; 345 } 346 347read_table_done: 348 kfree(buffer.pointer); 349 return size; 350} 351 352/** 353 * ibm_read_apci_table - callback for the sysfs apci_table file 354 * @filp: the open sysfs file 355 * @kobj: the kobject this binary attribute is a part of 356 * @bin_attr: struct bin_attribute for this file 357 * @buffer: the kernel space buffer to fill 358 * @pos: the offset into the file 359 * @size: the number of bytes requested 360 * 361 * Description: Gets registered with sysfs as the reader callback 362 * to be executed when /sys/bus/pci/slots/apci_table gets read. 363 * 364 * Since we don't get notified on open and close for this file, 365 * things get really tricky here... 366 * our solution is to only allow reading the table in all at once. 367 */ 368static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 369 struct bin_attribute *bin_attr, 370 char *buffer, loff_t pos, size_t size) 371{ 372 int bytes_read = -EINVAL; 373 char *table = NULL; 374 375 dbg("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); 376 377 if (pos == 0) { 378 bytes_read = ibm_get_table_from_acpi(&table); 379 if (bytes_read > 0 && bytes_read <= size) 380 memcpy(buffer, table, bytes_read); 381 kfree(table); 382 } 383 return bytes_read; 384} 385 386/** 387 * ibm_find_acpi_device - callback to find our ACPI device 388 * @handle: the ACPI handle of the device we are inspecting 389 * @lvl: depth into the namespace tree 390 * @context: a pointer to our handle to fill when we find the device 391 * @rv: a return value to fill if desired 392 * 393 * Description: Used as a callback when calling acpi_walk_namespace 394 * to find our device. When this method returns non-zero 395 * acpi_walk_namespace quits its search and returns our value. 396 */ 397static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 398 u32 lvl, void *context, void **rv) 399{ 400 acpi_handle *phandle = (acpi_handle *)context; 401 acpi_status status; 402 struct acpi_device_info *info; 403 int retval = 0; 404 405 status = acpi_get_object_info(handle, &info); 406 if (ACPI_FAILURE(status)) { 407 err("%s: Failed to get device information status=0x%x\n", 408 __func__, status); 409 return retval; 410 } 411 412 if (info->current_status && (info->valid & ACPI_VALID_HID) && 413 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || 414 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { 415 dbg("found hardware: %s, handle: %p\n", 416 info->hardware_id.string, handle); 417 *phandle = handle; 418 /* returning non-zero causes the search to stop 419 * and returns this value to the caller of 420 * acpi_walk_namespace, but it also causes some warnings 421 * in the acpi debug code to print... 422 */ 423 retval = FOUND_APCI; 424 } 425 kfree(info); 426 return retval; 427} 428 429static int __init ibm_acpiphp_init(void) 430{ 431 int retval = 0; 432 acpi_status status; 433 struct acpi_device *device; 434 struct kobject *sysdir = &pci_slots_kset->kobj; 435 436 dbg("%s\n", __func__); 437 438 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 439 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, 440 &ibm_acpi_handle, NULL) != FOUND_APCI) { 441 err("%s: acpi_walk_namespace failed\n", __func__); 442 retval = -ENODEV; 443 goto init_return; 444 } 445 dbg("%s: found IBM aPCI device\n", __func__); 446 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 447 err("%s: acpi_bus_get_device failed\n", __func__); 448 retval = -ENODEV; 449 goto init_return; 450 } 451 if (acpiphp_register_attention(&ibm_attention_info)) { 452 retval = -ENODEV; 453 goto init_return; 454 } 455 456 ibm_note.device = device; 457 status = acpi_install_notify_handler(ibm_acpi_handle, 458 ACPI_DEVICE_NOTIFY, ibm_handle_events, 459 &ibm_note); 460 if (ACPI_FAILURE(status)) { 461 err("%s: Failed to register notification handler\n", 462 __func__); 463 retval = -EBUSY; 464 goto init_cleanup; 465 } 466 467 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 468 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 469 470 return retval; 471 472init_cleanup: 473 acpiphp_unregister_attention(&ibm_attention_info); 474init_return: 475 return retval; 476} 477 478static void __exit ibm_acpiphp_exit(void) 479{ 480 acpi_status status; 481 struct kobject *sysdir = &pci_slots_kset->kobj; 482 483 dbg("%s\n", __func__); 484 485 if (acpiphp_unregister_attention(&ibm_attention_info)) 486 err("%s: attention info deregistration failed", __func__); 487 488 status = acpi_remove_notify_handler( 489 ibm_acpi_handle, 490 ACPI_DEVICE_NOTIFY, 491 ibm_handle_events); 492 if (ACPI_FAILURE(status)) 493 err("%s: Notification handler removal failed\n", __func__); 494 /* remove the /sys entries */ 495 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); 496} 497 498module_init(ibm_acpiphp_init); 499module_exit(ibm_acpiphp_exit); 500