1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * ACPI PCI Hot Plug IBM Extension 4 * 5 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com> 6 * Copyright (C) 2004 IBM Corp. 7 * 8 * All rights reserved. 9 * 10 * Send feedback to <vernux@us.ibm.com> 11 * 12 */ 13 14 #define pr_fmt(fmt) "acpiphp_ibm: " fmt 15 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <linux/module.h> 19 #include <linux/kernel.h> 20 #include <linux/sysfs.h> 21 #include <linux/kobject.h> 22 #include <linux/moduleparam.h> 23 #include <linux/pci.h> 24 #include <linux/uaccess.h> 25 26 #include "acpiphp.h" 27 #include "../pci.h" 28 29 #define DRIVER_VERSION "1.0.1" 30 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" 31 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" 32 33 34 MODULE_AUTHOR(DRIVER_AUTHOR); 35 MODULE_DESCRIPTION(DRIVER_DESC); 36 MODULE_LICENSE("GPL"); 37 MODULE_VERSION(DRIVER_VERSION); 38 39 #define FOUND_APCI 0x61504349 40 /* these are the names for the IBM ACPI pseudo-device */ 41 #define IBM_HARDWARE_ID1 "IBM37D0" 42 #define IBM_HARDWARE_ID2 "IBM37D4" 43 44 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun) 45 46 /* union apci_descriptor - allows access to the 47 * various device descriptors that are embedded in the 48 * aPCI table 49 */ 50 union apci_descriptor { 51 struct { 52 char sig[4]; 53 u8 len; 54 } header; 55 struct { 56 u8 type; 57 u8 len; 58 u16 slot_id; 59 u8 bus_id; 60 u8 dev_num; 61 u8 slot_num; 62 u8 slot_attr[2]; 63 u8 attn; 64 u8 status[2]; 65 u8 sun; 66 u8 res[3]; 67 } slot; 68 struct { 69 u8 type; 70 u8 len; 71 } generic; 72 }; 73 74 /* struct notification - keeps info about the device 75 * that cause the ACPI notification event 76 */ 77 struct notification { 78 struct acpi_device *device; 79 u8 event; 80 }; 81 82 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); 83 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); 84 static void ibm_handle_events(acpi_handle handle, u32 event, void *context); 85 static int ibm_get_table_from_acpi(char **bufp); 86 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 87 struct bin_attribute *bin_attr, 88 char *buffer, loff_t pos, size_t size); 89 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 90 u32 lvl, void *context, void **rv); 91 static int __init ibm_acpiphp_init(void); 92 static void __exit ibm_acpiphp_exit(void); 93 94 static acpi_handle ibm_acpi_handle; 95 static struct notification ibm_note; 96 static struct bin_attribute ibm_apci_table_attr __ro_after_init = { 97 .attr = { 98 .name = "apci_table", 99 .mode = S_IRUGO, 100 }, 101 .read = ibm_read_apci_table, 102 .write = NULL, 103 }; 104 static struct acpiphp_attention_info ibm_attention_info = 105 { 106 .set_attn = ibm_set_attention_status, 107 .get_attn = ibm_get_attention_status, 108 .owner = THIS_MODULE, 109 }; 110 111 /** 112 * ibm_slot_from_id - workaround for bad ibm hardware 113 * @id: the slot number that linux refers to the slot by 114 * 115 * Description: This method returns the aCPI slot descriptor 116 * corresponding to the Linux slot number. This descriptor 117 * has info about the aPCI slot id and attention status. 118 * This descriptor must be freed using kfree when done. 119 */ 120 static union apci_descriptor *ibm_slot_from_id(int id) 121 { 122 int ind = 0, size; 123 union apci_descriptor *ret = NULL, *des; 124 char *table; 125 126 size = ibm_get_table_from_acpi(&table); 127 if (size < 0) 128 return NULL; 129 des = (union apci_descriptor *)table; 130 if (memcmp(des->header.sig, "aPCI", 4) != 0) 131 goto ibm_slot_done; 132 133 des = (union apci_descriptor *)&table[ind += des->header.len]; 134 while (ind < size && (des->generic.type != 0x82 || 135 des->slot.slot_num != id)) { 136 des = (union apci_descriptor *)&table[ind += des->generic.len]; 137 } 138 139 if (ind < size && des->slot.slot_num == id) 140 ret = des; 141 142 ibm_slot_done: 143 if (ret) { 144 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); 145 if (ret) 146 memcpy(ret, des, sizeof(union apci_descriptor)); 147 } 148 kfree(table); 149 return ret; 150 } 151 152 /** 153 * ibm_set_attention_status - callback method to set the attention LED 154 * @slot: the hotplug_slot to work with 155 * @status: what to set the LED to (0 or 1) 156 * 157 * Description: This method is registered with the acpiphp module as a 158 * callback to do the device specific task of setting the LED status. 159 */ 160 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) 161 { 162 union acpi_object args[2]; 163 struct acpi_object_list params = { .pointer = args, .count = 2 }; 164 acpi_status stat; 165 unsigned long long rc; 166 union apci_descriptor *ibm_slot; 167 int id = hpslot_to_sun(slot); 168 169 ibm_slot = ibm_slot_from_id(id); 170 if (!ibm_slot) { 171 pr_err("APLS null ACPI descriptor for slot %d\n", id); 172 return -ENODEV; 173 } 174 175 pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__, 176 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 177 (status ? 1 : 0)); 178 179 args[0].type = ACPI_TYPE_INTEGER; 180 args[0].integer.value = ibm_slot->slot.slot_id; 181 args[1].type = ACPI_TYPE_INTEGER; 182 args[1].integer.value = (status) ? 1 : 0; 183 184 kfree(ibm_slot); 185 186 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); 187 if (ACPI_FAILURE(stat)) { 188 pr_err("APLS evaluation failed: 0x%08x\n", stat); 189 return -ENODEV; 190 } else if (!rc) { 191 pr_err("APLS method failed: 0x%08llx\n", rc); 192 return -ERANGE; 193 } 194 return 0; 195 } 196 197 /** 198 * ibm_get_attention_status - callback method to get attention LED status 199 * @slot: the hotplug_slot to work with 200 * @status: returns what the LED is set to (0 or 1) 201 * 202 * Description: This method is registered with the acpiphp module as a 203 * callback to do the device specific task of getting the LED status. 204 * 205 * Because there is no direct method of getting the LED status directly 206 * from an ACPI call, we read the aPCI table and parse out our 207 * slot descriptor to read the status from that. 208 */ 209 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) 210 { 211 union apci_descriptor *ibm_slot; 212 int id = hpslot_to_sun(slot); 213 214 ibm_slot = ibm_slot_from_id(id); 215 if (!ibm_slot) { 216 pr_err("APLS null ACPI descriptor for slot %d\n", id); 217 return -ENODEV; 218 } 219 220 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) 221 *status = 1; 222 else 223 *status = 0; 224 225 pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__, 226 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, 227 *status); 228 229 kfree(ibm_slot); 230 return 0; 231 } 232 233 /** 234 * ibm_handle_events - listens for ACPI events for the IBM37D0 device 235 * @handle: an ACPI handle to the device that caused the event 236 * @event: the event info (device specific) 237 * @context: passed context (our notification struct) 238 * 239 * Description: This method is registered as a callback with the ACPI 240 * subsystem it is called when this device has an event to notify the OS of. 241 * 242 * The events actually come from the device as two events that get 243 * synthesized into one event with data by this function. The event 244 * ID comes first and then the slot number that caused it. We report 245 * this as one event to the OS. 246 * 247 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will 248 * only re-enable the interrupt that causes this event AFTER this method 249 * has returned, thereby enforcing serial access for the notification struct. 250 */ 251 static void ibm_handle_events(acpi_handle handle, u32 event, void *context) 252 { 253 u8 detail = event & 0x0f; 254 u8 subevent = event & 0xf0; 255 struct notification *note = context; 256 257 pr_debug("%s: Received notification %02x\n", __func__, event); 258 259 if (subevent == 0x80) { 260 pr_debug("%s: generating bus event\n", __func__); 261 acpi_bus_generate_netlink_event(note->device->pnp.device_class, 262 dev_name(¬e->device->dev), 263 note->event, detail); 264 } else 265 note->event = event; 266 } 267 268 /** 269 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI 270 * @bufp: address to pointer to allocate for the table 271 * 272 * Description: This method reads the APLS buffer in from ACPI and 273 * stores the "stripped" table into a single buffer 274 * it allocates and passes the address back in bufp. 275 * 276 * If NULL is passed in as buffer, this method only calculates 277 * the size of the table and returns that without filling 278 * in the buffer. 279 * 280 * Returns < 0 on error or the size of the table on success. 281 */ 282 static int ibm_get_table_from_acpi(char **bufp) 283 { 284 union acpi_object *package; 285 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 286 acpi_status status; 287 char *lbuf = NULL; 288 int i, size = -EIO; 289 290 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); 291 if (ACPI_FAILURE(status)) { 292 pr_err("%s: APCI evaluation failed\n", __func__); 293 return -ENODEV; 294 } 295 296 package = (union acpi_object *) buffer.pointer; 297 if (!(package) || 298 (package->type != ACPI_TYPE_PACKAGE) || 299 !(package->package.elements)) { 300 pr_err("%s: Invalid APCI object\n", __func__); 301 goto read_table_done; 302 } 303 304 for (size = 0, i = 0; i < package->package.count; i++) { 305 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { 306 pr_err("%s: Invalid APCI element %d\n", __func__, i); 307 goto read_table_done; 308 } 309 size += package->package.elements[i].buffer.length; 310 } 311 312 if (bufp == NULL) 313 goto read_table_done; 314 315 lbuf = kzalloc(size, GFP_KERNEL); 316 pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", 317 __func__, package->package.count, size, lbuf); 318 319 if (lbuf) { 320 *bufp = lbuf; 321 } else { 322 size = -ENOMEM; 323 goto read_table_done; 324 } 325 326 size = 0; 327 for (i = 0; i < package->package.count; i++) { 328 memcpy(&lbuf[size], 329 package->package.elements[i].buffer.pointer, 330 package->package.elements[i].buffer.length); 331 size += package->package.elements[i].buffer.length; 332 } 333 334 read_table_done: 335 kfree(buffer.pointer); 336 return size; 337 } 338 339 /** 340 * ibm_read_apci_table - callback for the sysfs apci_table file 341 * @filp: the open sysfs file 342 * @kobj: the kobject this binary attribute is a part of 343 * @bin_attr: struct bin_attribute for this file 344 * @buffer: the kernel space buffer to fill 345 * @pos: the offset into the file 346 * @size: the number of bytes requested 347 * 348 * Description: Gets registered with sysfs as the reader callback 349 * to be executed when /sys/bus/pci/slots/apci_table gets read. 350 * 351 * Since we don't get notified on open and close for this file, 352 * things get really tricky here... 353 * our solution is to only allow reading the table in all at once. 354 */ 355 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, 356 struct bin_attribute *bin_attr, 357 char *buffer, loff_t pos, size_t size) 358 { 359 int bytes_read = -EINVAL; 360 char *table = NULL; 361 362 pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); 363 364 if (pos == 0) { 365 bytes_read = ibm_get_table_from_acpi(&table); 366 if (bytes_read > 0 && bytes_read <= size) 367 memcpy(buffer, table, bytes_read); 368 kfree(table); 369 } 370 return bytes_read; 371 } 372 373 /** 374 * ibm_find_acpi_device - callback to find our ACPI device 375 * @handle: the ACPI handle of the device we are inspecting 376 * @lvl: depth into the namespace tree 377 * @context: a pointer to our handle to fill when we find the device 378 * @rv: a return value to fill if desired 379 * 380 * Description: Used as a callback when calling acpi_walk_namespace 381 * to find our device. When this method returns non-zero 382 * acpi_walk_namespace quits its search and returns our value. 383 */ 384 static acpi_status __init ibm_find_acpi_device(acpi_handle handle, 385 u32 lvl, void *context, void **rv) 386 { 387 acpi_handle *phandle = (acpi_handle *)context; 388 unsigned long long current_status = 0; 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 acpi_bus_get_status_handle(handle, ¤t_status); 401 402 if (current_status && (info->valid & ACPI_VALID_HID) && 403 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || 404 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { 405 pr_debug("found hardware: %s, handle: %p\n", 406 info->hardware_id.string, handle); 407 *phandle = handle; 408 /* returning non-zero causes the search to stop 409 * and returns this value to the caller of 410 * acpi_walk_namespace, but it also causes some warnings 411 * in the acpi debug code to print... 412 */ 413 retval = FOUND_APCI; 414 } 415 kfree(info); 416 return retval; 417 } 418 419 static int __init ibm_acpiphp_init(void) 420 { 421 int retval = 0; 422 acpi_status status; 423 struct acpi_device *device; 424 struct kobject *sysdir = &pci_slots_kset->kobj; 425 426 pr_debug("%s\n", __func__); 427 428 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 429 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, 430 &ibm_acpi_handle, NULL) != FOUND_APCI) { 431 pr_err("%s: acpi_walk_namespace failed\n", __func__); 432 retval = -ENODEV; 433 goto init_return; 434 } 435 pr_debug("%s: found IBM aPCI device\n", __func__); 436 if (acpi_bus_get_device(ibm_acpi_handle, &device)) { 437 pr_err("%s: acpi_bus_get_device failed\n", __func__); 438 retval = -ENODEV; 439 goto init_return; 440 } 441 if (acpiphp_register_attention(&ibm_attention_info)) { 442 retval = -ENODEV; 443 goto init_return; 444 } 445 446 ibm_note.device = device; 447 status = acpi_install_notify_handler(ibm_acpi_handle, 448 ACPI_DEVICE_NOTIFY, ibm_handle_events, 449 &ibm_note); 450 if (ACPI_FAILURE(status)) { 451 pr_err("%s: Failed to register notification handler\n", 452 __func__); 453 retval = -EBUSY; 454 goto init_cleanup; 455 } 456 457 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); 458 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); 459 460 return retval; 461 462 init_cleanup: 463 acpiphp_unregister_attention(&ibm_attention_info); 464 init_return: 465 return retval; 466 } 467 468 static void __exit ibm_acpiphp_exit(void) 469 { 470 acpi_status status; 471 struct kobject *sysdir = &pci_slots_kset->kobj; 472 473 pr_debug("%s\n", __func__); 474 475 if (acpiphp_unregister_attention(&ibm_attention_info)) 476 pr_err("%s: attention info deregistration failed", __func__); 477 478 status = acpi_remove_notify_handler( 479 ibm_acpi_handle, 480 ACPI_DEVICE_NOTIFY, 481 ibm_handle_events); 482 if (ACPI_FAILURE(status)) 483 pr_err("%s: Notification handler removal failed\n", __func__); 484 /* remove the /sys entries */ 485 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); 486 } 487 488 module_init(ibm_acpiphp_init); 489 module_exit(ibm_acpiphp_exit); 490