1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Interfaces to retrieve and set PDC Stable options (firmware) 4 * 5 * Copyright (C) 2005-2006 Thibaut VARENE <varenet@parisc-linux.org> 6 * 7 * DEV NOTE: the PDC Procedures reference states that: 8 * "A minimum of 96 bytes of Stable Storage is required. Providing more than 9 * 96 bytes of Stable Storage is optional [...]. Failure to provide the 10 * optional locations from 96 to 192 results in the loss of certain 11 * functionality during boot." 12 * 13 * Since locations between 96 and 192 are the various paths, most (if not 14 * all) PA-RISC machines should have them. Anyway, for safety reasons, the 15 * following code can deal with just 96 bytes of Stable Storage, and all 16 * sizes between 96 and 192 bytes (provided they are multiple of struct 17 * pdc_module_path size, eg: 128, 160 and 192) to provide full information. 18 * One last word: there's one path we can always count on: the primary path. 19 * Anything above 224 bytes is used for 'osdep2' OS-dependent storage area. 20 * 21 * The first OS-dependent area should always be available. Obviously, this is 22 * not true for the other one. Also bear in mind that reading/writing from/to 23 * osdep2 is much more expensive than from/to osdep1. 24 * NOTE: We do not handle the 2 bytes OS-dep area at 0x5D, nor the first 25 * 2 bytes of storage available right after OSID. That's a total of 4 bytes 26 * sacrificed: -ETOOLAZY :P 27 * 28 * The current policy wrt file permissions is: 29 * - write: root only 30 * - read: (reading triggers PDC calls) ? root only : everyone 31 * The rationale is that PDC calls could hog (DoS) the machine. 32 * 33 * TODO: 34 * - timer/fastsize write calls 35 */ 36 37 #undef PDCS_DEBUG 38 #ifdef PDCS_DEBUG 39 #define DPRINTK(fmt, args...) printk(KERN_DEBUG fmt, ## args) 40 #else 41 #define DPRINTK(fmt, args...) 42 #endif 43 44 #include <linux/module.h> 45 #include <linux/init.h> 46 #include <linux/kernel.h> 47 #include <linux/string.h> 48 #include <linux/capability.h> 49 #include <linux/ctype.h> 50 #include <linux/sysfs.h> 51 #include <linux/kobject.h> 52 #include <linux/device.h> 53 #include <linux/errno.h> 54 #include <linux/spinlock.h> 55 56 #include <asm/pdc.h> 57 #include <asm/page.h> 58 #include <linux/uaccess.h> 59 #include <asm/hardware.h> 60 61 #define PDCS_VERSION "0.30" 62 #define PDCS_PREFIX "PDC Stable Storage" 63 64 #define PDCS_ADDR_PPRI 0x00 65 #define PDCS_ADDR_OSID 0x40 66 #define PDCS_ADDR_OSD1 0x48 67 #define PDCS_ADDR_DIAG 0x58 68 #define PDCS_ADDR_FSIZ 0x5C 69 #define PDCS_ADDR_PCON 0x60 70 #define PDCS_ADDR_PALT 0x80 71 #define PDCS_ADDR_PKBD 0xA0 72 #define PDCS_ADDR_OSD2 0xE0 73 74 MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>"); 75 MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data"); 76 MODULE_LICENSE("GPL"); 77 MODULE_VERSION(PDCS_VERSION); 78 79 /* holds Stable Storage size. Initialized once and for all, no lock needed */ 80 static unsigned long pdcs_size __read_mostly; 81 82 /* holds OS ID. Initialized once and for all, hopefully to 0x0006 */ 83 static u16 pdcs_osid __read_mostly; 84 85 /* This struct defines what we need to deal with a parisc pdc path entry */ 86 struct pdcspath_entry { 87 rwlock_t rw_lock; /* to protect path entry access */ 88 short ready; /* entry record is valid if != 0 */ 89 unsigned long addr; /* entry address in stable storage */ 90 char *name; /* entry name */ 91 struct pdc_module_path devpath; /* device path in parisc representation */ 92 struct device *dev; /* corresponding device */ 93 struct kobject kobj; 94 }; 95 96 struct pdcspath_attribute { 97 struct attribute attr; 98 ssize_t (*show)(struct pdcspath_entry *entry, char *buf); 99 ssize_t (*store)(struct pdcspath_entry *entry, const char *buf, size_t count); 100 }; 101 102 #define PDCSPATH_ENTRY(_addr, _name) \ 103 struct pdcspath_entry pdcspath_entry_##_name = { \ 104 .ready = 0, \ 105 .addr = _addr, \ 106 .name = __stringify(_name), \ 107 }; 108 109 #define PDCS_ATTR(_name, _mode, _show, _store) \ 110 struct kobj_attribute pdcs_attr_##_name = { \ 111 .attr = {.name = __stringify(_name), .mode = _mode}, \ 112 .show = _show, \ 113 .store = _store, \ 114 }; 115 116 #define PATHS_ATTR(_name, _mode, _show, _store) \ 117 struct pdcspath_attribute paths_attr_##_name = { \ 118 .attr = {.name = __stringify(_name), .mode = _mode}, \ 119 .show = _show, \ 120 .store = _store, \ 121 }; 122 123 #define to_pdcspath_attribute(_attr) container_of(_attr, struct pdcspath_attribute, attr) 124 #define to_pdcspath_entry(obj) container_of(obj, struct pdcspath_entry, kobj) 125 126 /** 127 * pdcspath_fetch - This function populates the path entry structs. 128 * @entry: A pointer to an allocated pdcspath_entry. 129 * 130 * The general idea is that you don't read from the Stable Storage every time 131 * you access the files provided by the facilities. We store a copy of the 132 * content of the stable storage WRT various paths in these structs. We read 133 * these structs when reading the files, and we will write to these structs when 134 * writing to the files, and only then write them back to the Stable Storage. 135 * 136 * This function expects to be called with @entry->rw_lock write-hold. 137 */ 138 static int 139 pdcspath_fetch(struct pdcspath_entry *entry) 140 { 141 struct pdc_module_path *devpath; 142 143 if (!entry) 144 return -EINVAL; 145 146 devpath = &entry->devpath; 147 148 DPRINTK("%s: fetch: 0x%p, 0x%p, addr: 0x%lx\n", __func__, 149 entry, devpath, entry->addr); 150 151 /* addr, devpath and count must be word aligned */ 152 if (pdc_stable_read(entry->addr, devpath, sizeof(*devpath)) != PDC_OK) 153 return -EIO; 154 155 /* Find the matching device. 156 NOTE: hardware_path overlays with pdc_module_path, so the nice cast can 157 be used */ 158 entry->dev = hwpath_to_device((struct hardware_path *)devpath); 159 160 entry->ready = 1; 161 162 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev); 163 164 return 0; 165 } 166 167 /** 168 * pdcspath_store - This function writes a path to stable storage. 169 * @entry: A pointer to an allocated pdcspath_entry. 170 * 171 * It can be used in two ways: either by passing it a preset devpath struct 172 * containing an already computed hardware path, or by passing it a device 173 * pointer, from which it'll find out the corresponding hardware path. 174 * For now we do not handle the case where there's an error in writing to the 175 * Stable Storage area, so you'd better not mess up the data :P 176 * 177 * This function expects to be called with @entry->rw_lock write-hold. 178 */ 179 static void 180 pdcspath_store(struct pdcspath_entry *entry) 181 { 182 struct pdc_module_path *devpath; 183 184 BUG_ON(!entry); 185 186 devpath = &entry->devpath; 187 188 /* We expect the caller to set the ready flag to 0 if the hardware 189 path struct provided is invalid, so that we know we have to fill it. 190 First case, we don't have a preset hwpath... */ 191 if (!entry->ready) { 192 /* ...but we have a device, map it */ 193 BUG_ON(!entry->dev); 194 device_to_hwpath(entry->dev, (struct hardware_path *)devpath); 195 } 196 /* else, we expect the provided hwpath to be valid. */ 197 198 DPRINTK("%s: store: 0x%p, 0x%p, addr: 0x%lx\n", __func__, 199 entry, devpath, entry->addr); 200 201 /* addr, devpath and count must be word aligned */ 202 if (pdc_stable_write(entry->addr, devpath, sizeof(*devpath)) != PDC_OK) 203 WARN(1, KERN_ERR "%s: an error occurred when writing to PDC.\n" 204 "It is likely that the Stable Storage data has been corrupted.\n" 205 "Please check it carefully upon next reboot.\n", __func__); 206 207 /* kobject is already registered */ 208 entry->ready = 2; 209 210 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev); 211 } 212 213 /** 214 * pdcspath_hwpath_read - This function handles hardware path pretty printing. 215 * @entry: An allocated and populated pdscpath_entry struct. 216 * @buf: The output buffer to write to. 217 * 218 * We will call this function to format the output of the hwpath attribute file. 219 */ 220 static ssize_t 221 pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf) 222 { 223 char *out = buf; 224 struct pdc_module_path *devpath; 225 short i; 226 227 if (!entry || !buf) 228 return -EINVAL; 229 230 read_lock(&entry->rw_lock); 231 devpath = &entry->devpath; 232 i = entry->ready; 233 read_unlock(&entry->rw_lock); 234 235 if (!i) /* entry is not ready */ 236 return -ENODATA; 237 238 for (i = 0; i < 6; i++) { 239 if (devpath->path.bc[i] < 0) 240 continue; 241 out += sprintf(out, "%d/", devpath->path.bc[i]); 242 } 243 out += sprintf(out, "%u\n", (unsigned char)devpath->path.mod); 244 245 return out - buf; 246 } 247 248 /** 249 * pdcspath_hwpath_write - This function handles hardware path modifying. 250 * @entry: An allocated and populated pdscpath_entry struct. 251 * @buf: The input buffer to read from. 252 * @count: The number of bytes to be read. 253 * 254 * We will call this function to change the current hardware path. 255 * Hardware paths are to be given '/'-delimited, without brackets. 256 * We make sure that the provided path actually maps to an existing 257 * device, BUT nothing would prevent some foolish user to set the path to some 258 * PCI bridge or even a CPU... 259 * A better work around would be to make sure we are at the end of a device tree 260 * for instance, but it would be IMHO beyond the simple scope of that driver. 261 * The aim is to provide a facility. Data correctness is left to userland. 262 */ 263 static ssize_t 264 pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t count) 265 { 266 struct hardware_path hwpath; 267 unsigned short i; 268 char in[64], *temp; 269 struct device *dev; 270 int ret; 271 272 if (!entry || !buf || !count) 273 return -EINVAL; 274 275 /* We'll use a local copy of buf */ 276 count = min_t(size_t, count, sizeof(in)-1); 277 strscpy(in, buf, count + 1); 278 279 /* Let's clean up the target. 0xff is a blank pattern */ 280 memset(&hwpath, 0xff, sizeof(hwpath)); 281 282 /* First, pick the mod field (the last one of the input string) */ 283 if (!(temp = strrchr(in, '/'))) 284 return -EINVAL; 285 286 hwpath.mod = simple_strtoul(temp+1, NULL, 10); 287 in[temp-in] = '\0'; /* truncate the remaining string. just precaution */ 288 DPRINTK("%s: mod: %d\n", __func__, hwpath.mod); 289 290 /* Then, loop for each delimiter, making sure we don't have too many. 291 we write the bc fields in a down-top way. No matter what, we stop 292 before writing the last field. If there are too many fields anyway, 293 then the user is a moron and it'll be caught up later when we'll 294 check the consistency of the given hwpath. */ 295 for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) { 296 hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10); 297 in[temp-in] = '\0'; 298 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.path.bc[i]); 299 } 300 301 /* Store the final field */ 302 hwpath.bc[i] = simple_strtoul(in, NULL, 10); 303 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.path.bc[i]); 304 305 /* Now we check that the user isn't trying to lure us */ 306 if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) { 307 printk(KERN_WARNING "%s: attempt to set invalid \"%s\" " 308 "hardware path: %s\n", __func__, entry->name, buf); 309 return -EINVAL; 310 } 311 312 /* So far so good, let's get in deep */ 313 write_lock(&entry->rw_lock); 314 entry->ready = 0; 315 entry->dev = dev; 316 317 /* Now, dive in. Write back to the hardware */ 318 pdcspath_store(entry); 319 320 /* Update the symlink to the real device */ 321 sysfs_remove_link(&entry->kobj, "device"); 322 write_unlock(&entry->rw_lock); 323 324 ret = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 325 WARN_ON(ret); 326 327 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n", 328 entry->name, buf); 329 330 return count; 331 } 332 333 /** 334 * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing. 335 * @entry: An allocated and populated pdscpath_entry struct. 336 * @buf: The output buffer to write to. 337 * 338 * We will call this function to format the output of the layer attribute file. 339 */ 340 static ssize_t 341 pdcspath_layer_read(struct pdcspath_entry *entry, char *buf) 342 { 343 char *out = buf; 344 struct pdc_module_path *devpath; 345 short i; 346 347 if (!entry || !buf) 348 return -EINVAL; 349 350 read_lock(&entry->rw_lock); 351 devpath = &entry->devpath; 352 i = entry->ready; 353 read_unlock(&entry->rw_lock); 354 355 if (!i) /* entry is not ready */ 356 return -ENODATA; 357 358 for (i = 0; i < 6 && devpath->layers[i]; i++) 359 out += sprintf(out, "%u ", devpath->layers[i]); 360 361 out += sprintf(out, "\n"); 362 363 return out - buf; 364 } 365 366 /** 367 * pdcspath_layer_write - This function handles extended layer modifying. 368 * @entry: An allocated and populated pdscpath_entry struct. 369 * @buf: The input buffer to read from. 370 * @count: The number of bytes to be read. 371 * 372 * We will call this function to change the current layer value. 373 * Layers are to be given '.'-delimited, without brackets. 374 * XXX beware we are far less checky WRT input data provided than for hwpath. 375 * Potential harm can be done, since there's no way to check the validity of 376 * the layer fields. 377 */ 378 static ssize_t 379 pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count) 380 { 381 unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */ 382 unsigned short i; 383 char in[64], *temp; 384 385 if (!entry || !buf || !count) 386 return -EINVAL; 387 388 /* We'll use a local copy of buf */ 389 count = min_t(size_t, count, sizeof(in)-1); 390 strscpy(in, buf, count + 1); 391 392 /* Let's clean up the target. 0 is a blank pattern */ 393 memset(&layers, 0, sizeof(layers)); 394 395 /* First, pick the first layer */ 396 if (unlikely(!isdigit(*in))) 397 return -EINVAL; 398 layers[0] = simple_strtoul(in, NULL, 10); 399 DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]); 400 401 temp = in; 402 for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) { 403 if (unlikely(!isdigit(*(++temp)))) 404 return -EINVAL; 405 layers[i] = simple_strtoul(temp, NULL, 10); 406 DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]); 407 } 408 409 /* So far so good, let's get in deep */ 410 write_lock(&entry->rw_lock); 411 412 /* First, overwrite the current layers with the new ones, not touching 413 the hardware path. */ 414 memcpy(&entry->devpath.layers, &layers, sizeof(layers)); 415 416 /* Now, dive in. Write back to the hardware */ 417 pdcspath_store(entry); 418 write_unlock(&entry->rw_lock); 419 420 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n", 421 entry->name, buf); 422 423 return count; 424 } 425 426 /** 427 * pdcspath_attr_show - Generic read function call wrapper. 428 * @kobj: The kobject to get info from. 429 * @attr: The attribute looked upon. 430 * @buf: The output buffer. 431 */ 432 static ssize_t 433 pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) 434 { 435 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 436 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 437 ssize_t ret = 0; 438 439 if (pdcs_attr->show) 440 ret = pdcs_attr->show(entry, buf); 441 442 return ret; 443 } 444 445 /** 446 * pdcspath_attr_store - Generic write function call wrapper. 447 * @kobj: The kobject to write info to. 448 * @attr: The attribute to be modified. 449 * @buf: The input buffer. 450 * @count: The size of the buffer. 451 */ 452 static ssize_t 453 pdcspath_attr_store(struct kobject *kobj, struct attribute *attr, 454 const char *buf, size_t count) 455 { 456 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 457 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 458 ssize_t ret = 0; 459 460 if (!capable(CAP_SYS_ADMIN)) 461 return -EACCES; 462 463 if (pdcs_attr->store) 464 ret = pdcs_attr->store(entry, buf, count); 465 466 return ret; 467 } 468 469 static const struct sysfs_ops pdcspath_attr_ops = { 470 .show = pdcspath_attr_show, 471 .store = pdcspath_attr_store, 472 }; 473 474 /* These are the two attributes of any PDC path. */ 475 static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write); 476 static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write); 477 478 static struct attribute *paths_subsys_attrs[] = { 479 &paths_attr_hwpath.attr, 480 &paths_attr_layer.attr, 481 NULL, 482 }; 483 ATTRIBUTE_GROUPS(paths_subsys); 484 485 /* Specific kobject type for our PDC paths */ 486 static struct kobj_type ktype_pdcspath = { 487 .sysfs_ops = &pdcspath_attr_ops, 488 .default_groups = paths_subsys_groups, 489 }; 490 491 /* We hard define the 4 types of path we expect to find */ 492 static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary); 493 static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console); 494 static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative); 495 static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard); 496 497 /* An array containing all PDC paths we will deal with */ 498 static struct pdcspath_entry *pdcspath_entries[] = { 499 &pdcspath_entry_primary, 500 &pdcspath_entry_alternative, 501 &pdcspath_entry_console, 502 &pdcspath_entry_keyboard, 503 NULL, 504 }; 505 506 507 /* For more insight of what's going on here, refer to PDC Procedures doc, 508 * Section PDC_STABLE */ 509 510 /** 511 * pdcs_size_read - Stable Storage size output. 512 * @buf: The output buffer to write to. 513 */ 514 static ssize_t pdcs_size_read(struct kobject *kobj, 515 struct kobj_attribute *attr, 516 char *buf) 517 { 518 char *out = buf; 519 520 if (!buf) 521 return -EINVAL; 522 523 /* show the size of the stable storage */ 524 out += sprintf(out, "%ld\n", pdcs_size); 525 526 return out - buf; 527 } 528 529 /** 530 * pdcs_auto_read - Stable Storage autoboot/search flag output. 531 * @buf: The output buffer to write to. 532 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 533 */ 534 static ssize_t pdcs_auto_read(struct kobject *kobj, 535 struct kobj_attribute *attr, 536 char *buf, int knob) 537 { 538 char *out = buf; 539 struct pdcspath_entry *pathentry; 540 541 if (!buf) 542 return -EINVAL; 543 544 /* Current flags are stored in primary boot path entry */ 545 pathentry = &pdcspath_entry_primary; 546 547 read_lock(&pathentry->rw_lock); 548 out += sprintf(out, "%s\n", (pathentry->devpath.path.flags & knob) ? 549 "On" : "Off"); 550 read_unlock(&pathentry->rw_lock); 551 552 return out - buf; 553 } 554 555 /** 556 * pdcs_autoboot_read - Stable Storage autoboot flag output. 557 * @buf: The output buffer to write to. 558 */ 559 static ssize_t pdcs_autoboot_read(struct kobject *kobj, 560 struct kobj_attribute *attr, char *buf) 561 { 562 return pdcs_auto_read(kobj, attr, buf, PF_AUTOBOOT); 563 } 564 565 /** 566 * pdcs_autosearch_read - Stable Storage autoboot flag output. 567 * @buf: The output buffer to write to. 568 */ 569 static ssize_t pdcs_autosearch_read(struct kobject *kobj, 570 struct kobj_attribute *attr, char *buf) 571 { 572 return pdcs_auto_read(kobj, attr, buf, PF_AUTOSEARCH); 573 } 574 575 /** 576 * pdcs_timer_read - Stable Storage timer count output (in seconds). 577 * @buf: The output buffer to write to. 578 * 579 * The value of the timer field correponds to a number of seconds in powers of 2. 580 */ 581 static ssize_t pdcs_timer_read(struct kobject *kobj, 582 struct kobj_attribute *attr, char *buf) 583 { 584 char *out = buf; 585 struct pdcspath_entry *pathentry; 586 587 if (!buf) 588 return -EINVAL; 589 590 /* Current flags are stored in primary boot path entry */ 591 pathentry = &pdcspath_entry_primary; 592 593 /* print the timer value in seconds */ 594 read_lock(&pathentry->rw_lock); 595 out += sprintf(out, "%u\n", (pathentry->devpath.path.flags & PF_TIMER) ? 596 (1 << (pathentry->devpath.path.flags & PF_TIMER)) : 0); 597 read_unlock(&pathentry->rw_lock); 598 599 return out - buf; 600 } 601 602 /** 603 * pdcs_osid_read - Stable Storage OS ID register output. 604 * @buf: The output buffer to write to. 605 */ 606 static ssize_t pdcs_osid_read(struct kobject *kobj, 607 struct kobj_attribute *attr, char *buf) 608 { 609 char *out = buf; 610 611 if (!buf) 612 return -EINVAL; 613 614 out += sprintf(out, "%s dependent data (0x%.4x)\n", 615 os_id_to_string(pdcs_osid), pdcs_osid); 616 617 return out - buf; 618 } 619 620 /** 621 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output. 622 * @buf: The output buffer to write to. 623 * 624 * This can hold 16 bytes of OS-Dependent data. 625 */ 626 static ssize_t pdcs_osdep1_read(struct kobject *kobj, 627 struct kobj_attribute *attr, char *buf) 628 { 629 char *out = buf; 630 u32 result[4]; 631 632 if (!buf) 633 return -EINVAL; 634 635 if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK) 636 return -EIO; 637 638 out += sprintf(out, "0x%.8x\n", result[0]); 639 out += sprintf(out, "0x%.8x\n", result[1]); 640 out += sprintf(out, "0x%.8x\n", result[2]); 641 out += sprintf(out, "0x%.8x\n", result[3]); 642 643 return out - buf; 644 } 645 646 /** 647 * pdcs_diagnostic_read - Stable Storage Diagnostic register output. 648 * @buf: The output buffer to write to. 649 * 650 * I have NFC how to interpret the content of that register ;-). 651 */ 652 static ssize_t pdcs_diagnostic_read(struct kobject *kobj, 653 struct kobj_attribute *attr, char *buf) 654 { 655 char *out = buf; 656 u32 result; 657 658 if (!buf) 659 return -EINVAL; 660 661 /* get diagnostic */ 662 if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK) 663 return -EIO; 664 665 out += sprintf(out, "0x%.4x\n", (result >> 16)); 666 667 return out - buf; 668 } 669 670 /** 671 * pdcs_fastsize_read - Stable Storage FastSize register output. 672 * @buf: The output buffer to write to. 673 * 674 * This register holds the amount of system RAM to be tested during boot sequence. 675 */ 676 static ssize_t pdcs_fastsize_read(struct kobject *kobj, 677 struct kobj_attribute *attr, char *buf) 678 { 679 char *out = buf; 680 u32 result; 681 682 if (!buf) 683 return -EINVAL; 684 685 /* get fast-size */ 686 if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK) 687 return -EIO; 688 689 if ((result & 0x0F) < 0x0E) 690 out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256); 691 else 692 out += sprintf(out, "All"); 693 out += sprintf(out, "\n"); 694 695 return out - buf; 696 } 697 698 /** 699 * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output. 700 * @buf: The output buffer to write to. 701 * 702 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available. 703 */ 704 static ssize_t pdcs_osdep2_read(struct kobject *kobj, 705 struct kobj_attribute *attr, char *buf) 706 { 707 char *out = buf; 708 unsigned long size; 709 unsigned short i; 710 u32 result; 711 712 if (unlikely(pdcs_size <= 224)) 713 return -ENODATA; 714 715 size = pdcs_size - 224; 716 717 if (!buf) 718 return -EINVAL; 719 720 for (i=0; i<size; i+=4) { 721 if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result, 722 sizeof(result)) != PDC_OK)) 723 return -EIO; 724 out += sprintf(out, "0x%.8x\n", result); 725 } 726 727 return out - buf; 728 } 729 730 /** 731 * pdcs_auto_write - This function handles autoboot/search flag modifying. 732 * @buf: The input buffer to read from. 733 * @count: The number of bytes to be read. 734 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 735 * 736 * We will call this function to change the current autoboot flag. 737 * We expect a precise syntax: 738 * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On 739 */ 740 static ssize_t pdcs_auto_write(struct kobject *kobj, 741 struct kobj_attribute *attr, const char *buf, 742 size_t count, int knob) 743 { 744 struct pdcspath_entry *pathentry; 745 unsigned char flags; 746 char in[8], *temp; 747 char c; 748 749 if (!capable(CAP_SYS_ADMIN)) 750 return -EACCES; 751 752 if (!buf || !count) 753 return -EINVAL; 754 755 /* We'll use a local copy of buf */ 756 count = min_t(size_t, count, sizeof(in)-1); 757 strscpy(in, buf, count + 1); 758 759 /* Current flags are stored in primary boot path entry */ 760 pathentry = &pdcspath_entry_primary; 761 762 /* Be nice to the existing flag record */ 763 read_lock(&pathentry->rw_lock); 764 flags = pathentry->devpath.path.flags; 765 read_unlock(&pathentry->rw_lock); 766 767 DPRINTK("%s: flags before: 0x%X\n", __func__, flags); 768 769 temp = skip_spaces(in); 770 771 c = *temp++ - '0'; 772 if ((c != 0) && (c != 1)) 773 goto parse_error; 774 if (c == 0) 775 flags &= ~knob; 776 else 777 flags |= knob; 778 779 DPRINTK("%s: flags after: 0x%X\n", __func__, flags); 780 781 /* So far so good, let's get in deep */ 782 write_lock(&pathentry->rw_lock); 783 784 /* Change the path entry flags first */ 785 pathentry->devpath.path.flags = flags; 786 787 /* Now, dive in. Write back to the hardware */ 788 pdcspath_store(pathentry); 789 write_unlock(&pathentry->rw_lock); 790 791 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n", 792 (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch", 793 (flags & knob) ? "On" : "Off"); 794 795 return count; 796 797 parse_error: 798 printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__); 799 return -EINVAL; 800 } 801 802 /** 803 * pdcs_autoboot_write - This function handles autoboot flag modifying. 804 * @buf: The input buffer to read from. 805 * @count: The number of bytes to be read. 806 * 807 * We will call this function to change the current boot flags. 808 * We expect a precise syntax: 809 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 810 */ 811 static ssize_t pdcs_autoboot_write(struct kobject *kobj, 812 struct kobj_attribute *attr, 813 const char *buf, size_t count) 814 { 815 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOBOOT); 816 } 817 818 /** 819 * pdcs_autosearch_write - This function handles autosearch flag modifying. 820 * @buf: The input buffer to read from. 821 * @count: The number of bytes to be read. 822 * 823 * We will call this function to change the current boot flags. 824 * We expect a precise syntax: 825 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 826 */ 827 static ssize_t pdcs_autosearch_write(struct kobject *kobj, 828 struct kobj_attribute *attr, 829 const char *buf, size_t count) 830 { 831 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOSEARCH); 832 } 833 834 /** 835 * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input. 836 * @buf: The input buffer to read from. 837 * @count: The number of bytes to be read. 838 * 839 * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte 840 * write approach. It's up to userspace to deal with it when constructing 841 * its input buffer. 842 */ 843 static ssize_t pdcs_osdep1_write(struct kobject *kobj, 844 struct kobj_attribute *attr, 845 const char *buf, size_t count) 846 { 847 u8 in[16]; 848 849 if (!capable(CAP_SYS_ADMIN)) 850 return -EACCES; 851 852 if (!buf || !count) 853 return -EINVAL; 854 855 if (unlikely(pdcs_osid != OS_ID_LINUX)) 856 return -EPERM; 857 858 if (count > 16) 859 return -EMSGSIZE; 860 861 /* We'll use a local copy of buf */ 862 memset(in, 0, 16); 863 memcpy(in, buf, count); 864 865 if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK) 866 return -EIO; 867 868 return count; 869 } 870 871 /** 872 * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input. 873 * @buf: The input buffer to read from. 874 * @count: The number of bytes to be read. 875 * 876 * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a 877 * byte-by-byte write approach. It's up to userspace to deal with it when 878 * constructing its input buffer. 879 */ 880 static ssize_t pdcs_osdep2_write(struct kobject *kobj, 881 struct kobj_attribute *attr, 882 const char *buf, size_t count) 883 { 884 unsigned long size; 885 unsigned short i; 886 u8 in[4]; 887 888 if (!capable(CAP_SYS_ADMIN)) 889 return -EACCES; 890 891 if (!buf || !count) 892 return -EINVAL; 893 894 if (unlikely(pdcs_size <= 224)) 895 return -ENOSYS; 896 897 if (unlikely(pdcs_osid != OS_ID_LINUX)) 898 return -EPERM; 899 900 size = pdcs_size - 224; 901 902 if (count > size) 903 return -EMSGSIZE; 904 905 /* We'll use a local copy of buf */ 906 907 for (i=0; i<count; i+=4) { 908 memset(in, 0, 4); 909 memcpy(in, buf+i, (count-i < 4) ? count-i : 4); 910 if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in, 911 sizeof(in)) != PDC_OK)) 912 return -EIO; 913 } 914 915 return count; 916 } 917 918 /* The remaining attributes. */ 919 static PDCS_ATTR(size, 0444, pdcs_size_read, NULL); 920 static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write); 921 static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write); 922 static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL); 923 static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL); 924 static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write); 925 static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL); 926 static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL); 927 static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write); 928 929 static struct attribute *pdcs_subsys_attrs[] = { 930 &pdcs_attr_size.attr, 931 &pdcs_attr_autoboot.attr, 932 &pdcs_attr_autosearch.attr, 933 &pdcs_attr_timer.attr, 934 &pdcs_attr_osid.attr, 935 &pdcs_attr_osdep1.attr, 936 &pdcs_attr_diagnostic.attr, 937 &pdcs_attr_fastsize.attr, 938 &pdcs_attr_osdep2.attr, 939 NULL, 940 }; 941 942 static const struct attribute_group pdcs_attr_group = { 943 .attrs = pdcs_subsys_attrs, 944 }; 945 946 static struct kobject *stable_kobj; 947 static struct kset *paths_kset; 948 949 /** 950 * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage. 951 * 952 * It creates kobjects corresponding to each path entry with nice sysfs 953 * links to the real device. This is where the magic takes place: when 954 * registering the subsystem attributes during module init, each kobject hereby 955 * created will show in the sysfs tree as a folder containing files as defined 956 * by path_subsys_attr[]. 957 */ 958 static inline int __init 959 pdcs_register_pathentries(void) 960 { 961 unsigned short i; 962 struct pdcspath_entry *entry; 963 int err; 964 965 /* Initialize the entries rw_lock before anything else */ 966 for (i = 0; (entry = pdcspath_entries[i]); i++) 967 rwlock_init(&entry->rw_lock); 968 969 for (i = 0; (entry = pdcspath_entries[i]); i++) { 970 write_lock(&entry->rw_lock); 971 err = pdcspath_fetch(entry); 972 write_unlock(&entry->rw_lock); 973 974 if (err < 0) 975 continue; 976 977 entry->kobj.kset = paths_kset; 978 err = kobject_init_and_add(&entry->kobj, &ktype_pdcspath, NULL, 979 "%s", entry->name); 980 if (err) { 981 kobject_put(&entry->kobj); 982 return err; 983 } 984 985 /* kobject is now registered */ 986 write_lock(&entry->rw_lock); 987 entry->ready = 2; 988 write_unlock(&entry->rw_lock); 989 990 /* Add a nice symlink to the real device */ 991 if (entry->dev) { 992 err = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 993 WARN_ON(err); 994 } 995 996 kobject_uevent(&entry->kobj, KOBJ_ADD); 997 } 998 999 return 0; 1000 } 1001 1002 /** 1003 * pdcs_unregister_pathentries - Routine called when unregistering the module. 1004 */ 1005 static inline void 1006 pdcs_unregister_pathentries(void) 1007 { 1008 unsigned short i; 1009 struct pdcspath_entry *entry; 1010 1011 for (i = 0; (entry = pdcspath_entries[i]); i++) { 1012 read_lock(&entry->rw_lock); 1013 if (entry->ready >= 2) 1014 kobject_put(&entry->kobj); 1015 read_unlock(&entry->rw_lock); 1016 } 1017 } 1018 1019 /* 1020 * For now we register the stable subsystem with the firmware subsystem 1021 * and the paths subsystem with the stable subsystem 1022 */ 1023 static int __init 1024 pdc_stable_init(void) 1025 { 1026 int rc = 0, error = 0; 1027 u32 result; 1028 1029 /* find the size of the stable storage */ 1030 if (pdc_stable_get_size(&pdcs_size) != PDC_OK) 1031 return -ENODEV; 1032 1033 /* make sure we have enough data */ 1034 if (pdcs_size < 96) 1035 return -ENODATA; 1036 1037 printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION); 1038 1039 /* get OSID */ 1040 if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK) 1041 return -EIO; 1042 1043 /* the actual result is 16 bits away */ 1044 pdcs_osid = (u16)(result >> 16); 1045 1046 /* For now we'll register the directory at /sys/firmware/stable */ 1047 stable_kobj = kobject_create_and_add("stable", firmware_kobj); 1048 if (!stable_kobj) { 1049 rc = -ENOMEM; 1050 goto fail_firmreg; 1051 } 1052 1053 /* Don't forget the root entries */ 1054 error = sysfs_create_group(stable_kobj, &pdcs_attr_group); 1055 1056 /* register the paths kset as a child of the stable kset */ 1057 paths_kset = kset_create_and_add("paths", NULL, stable_kobj); 1058 if (!paths_kset) { 1059 rc = -ENOMEM; 1060 goto fail_ksetreg; 1061 } 1062 1063 /* now we create all "files" for the paths kset */ 1064 if ((rc = pdcs_register_pathentries())) 1065 goto fail_pdcsreg; 1066 1067 return rc; 1068 1069 fail_pdcsreg: 1070 pdcs_unregister_pathentries(); 1071 kset_unregister(paths_kset); 1072 1073 fail_ksetreg: 1074 kobject_put(stable_kobj); 1075 1076 fail_firmreg: 1077 printk(KERN_INFO PDCS_PREFIX " bailing out\n"); 1078 return rc; 1079 } 1080 1081 static void __exit 1082 pdc_stable_exit(void) 1083 { 1084 pdcs_unregister_pathentries(); 1085 kset_unregister(paths_kset); 1086 kobject_put(stable_kobj); 1087 } 1088 1089 1090 module_init(pdc_stable_init); 1091 module_exit(pdc_stable_exit); 1092