1/* 2 * Interfaces to retrieve and set PDC Stable options (firmware) 3 * 4 * Copyright (C) 2005-2006 Thibaut VARENE <varenet@parisc-linux.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License, version 2, as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 * 19 * 20 * DEV NOTE: the PDC Procedures reference states that: 21 * "A minimum of 96 bytes of Stable Storage is required. Providing more than 22 * 96 bytes of Stable Storage is optional [...]. Failure to provide the 23 * optional locations from 96 to 192 results in the loss of certain 24 * functionality during boot." 25 * 26 * Since locations between 96 and 192 are the various paths, most (if not 27 * all) PA-RISC machines should have them. Anyway, for safety reasons, the 28 * following code can deal with just 96 bytes of Stable Storage, and all 29 * sizes between 96 and 192 bytes (provided they are multiple of struct 30 * device_path size, eg: 128, 160 and 192) to provide full information. 31 * One last word: there's one path we can always count on: the primary path. 32 * Anything above 224 bytes is used for 'osdep2' OS-dependent storage area. 33 * 34 * The first OS-dependent area should always be available. Obviously, this is 35 * not true for the other one. Also bear in mind that reading/writing from/to 36 * osdep2 is much more expensive than from/to osdep1. 37 * NOTE: We do not handle the 2 bytes OS-dep area at 0x5D, nor the first 38 * 2 bytes of storage available right after OSID. That's a total of 4 bytes 39 * sacrificed: -ETOOLAZY :P 40 * 41 * The current policy wrt file permissions is: 42 * - write: root only 43 * - read: (reading triggers PDC calls) ? root only : everyone 44 * The rationale is that PDC calls could hog (DoS) the machine. 45 * 46 * TODO: 47 * - timer/fastsize write calls 48 */ 49 50#undef PDCS_DEBUG 51#ifdef PDCS_DEBUG 52#define DPRINTK(fmt, args...) printk(KERN_DEBUG fmt, ## args) 53#else 54#define DPRINTK(fmt, args...) 55#endif 56 57#include <linux/module.h> 58#include <linux/init.h> 59#include <linux/kernel.h> 60#include <linux/string.h> 61#include <linux/capability.h> 62#include <linux/ctype.h> 63#include <linux/sysfs.h> 64#include <linux/kobject.h> 65#include <linux/device.h> 66#include <linux/errno.h> 67#include <linux/spinlock.h> 68 69#include <asm/pdc.h> 70#include <asm/page.h> 71#include <asm/uaccess.h> 72#include <asm/hardware.h> 73 74#define PDCS_VERSION "0.30" 75#define PDCS_PREFIX "PDC Stable Storage" 76 77#define PDCS_ADDR_PPRI 0x00 78#define PDCS_ADDR_OSID 0x40 79#define PDCS_ADDR_OSD1 0x48 80#define PDCS_ADDR_DIAG 0x58 81#define PDCS_ADDR_FSIZ 0x5C 82#define PDCS_ADDR_PCON 0x60 83#define PDCS_ADDR_PALT 0x80 84#define PDCS_ADDR_PKBD 0xA0 85#define PDCS_ADDR_OSD2 0xE0 86 87MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>"); 88MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data"); 89MODULE_LICENSE("GPL"); 90MODULE_VERSION(PDCS_VERSION); 91 92/* holds Stable Storage size. Initialized once and for all, no lock needed */ 93static unsigned long pdcs_size __read_mostly; 94 95/* holds OS ID. Initialized once and for all, hopefully to 0x0006 */ 96static u16 pdcs_osid __read_mostly; 97 98/* This struct defines what we need to deal with a parisc pdc path entry */ 99struct pdcspath_entry { 100 rwlock_t rw_lock; /* to protect path entry access */ 101 short ready; /* entry record is valid if != 0 */ 102 unsigned long addr; /* entry address in stable storage */ 103 char *name; /* entry name */ 104 struct device_path devpath; /* device path in parisc representation */ 105 struct device *dev; /* corresponding device */ 106 struct kobject kobj; 107}; 108 109struct pdcspath_attribute { 110 struct attribute attr; 111 ssize_t (*show)(struct pdcspath_entry *entry, char *buf); 112 ssize_t (*store)(struct pdcspath_entry *entry, const char *buf, size_t count); 113}; 114 115#define PDCSPATH_ENTRY(_addr, _name) \ 116struct pdcspath_entry pdcspath_entry_##_name = { \ 117 .ready = 0, \ 118 .addr = _addr, \ 119 .name = __stringify(_name), \ 120}; 121 122#define PDCS_ATTR(_name, _mode, _show, _store) \ 123struct kobj_attribute pdcs_attr_##_name = { \ 124 .attr = {.name = __stringify(_name), .mode = _mode}, \ 125 .show = _show, \ 126 .store = _store, \ 127}; 128 129#define PATHS_ATTR(_name, _mode, _show, _store) \ 130struct pdcspath_attribute paths_attr_##_name = { \ 131 .attr = {.name = __stringify(_name), .mode = _mode}, \ 132 .show = _show, \ 133 .store = _store, \ 134}; 135 136#define to_pdcspath_attribute(_attr) container_of(_attr, struct pdcspath_attribute, attr) 137#define to_pdcspath_entry(obj) container_of(obj, struct pdcspath_entry, kobj) 138 139/** 140 * pdcspath_fetch - This function populates the path entry structs. 141 * @entry: A pointer to an allocated pdcspath_entry. 142 * 143 * The general idea is that you don't read from the Stable Storage every time 144 * you access the files provided by the facilites. We store a copy of the 145 * content of the stable storage WRT various paths in these structs. We read 146 * these structs when reading the files, and we will write to these structs when 147 * writing to the files, and only then write them back to the Stable Storage. 148 * 149 * This function expects to be called with @entry->rw_lock write-hold. 150 */ 151static int 152pdcspath_fetch(struct pdcspath_entry *entry) 153{ 154 struct device_path *devpath; 155 156 if (!entry) 157 return -EINVAL; 158 159 devpath = &entry->devpath; 160 161 DPRINTK("%s: fetch: 0x%p, 0x%p, addr: 0x%lx\n", __func__, 162 entry, devpath, entry->addr); 163 164 /* addr, devpath and count must be word aligned */ 165 if (pdc_stable_read(entry->addr, devpath, sizeof(*devpath)) != PDC_OK) 166 return -EIO; 167 168 /* Find the matching device. 169 NOTE: hardware_path overlays with device_path, so the nice cast can 170 be used */ 171 entry->dev = hwpath_to_device((struct hardware_path *)devpath); 172 173 entry->ready = 1; 174 175 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev); 176 177 return 0; 178} 179 180/** 181 * pdcspath_store - This function writes a path to stable storage. 182 * @entry: A pointer to an allocated pdcspath_entry. 183 * 184 * It can be used in two ways: either by passing it a preset devpath struct 185 * containing an already computed hardware path, or by passing it a device 186 * pointer, from which it'll find out the corresponding hardware path. 187 * For now we do not handle the case where there's an error in writing to the 188 * Stable Storage area, so you'd better not mess up the data :P 189 * 190 * This function expects to be called with @entry->rw_lock write-hold. 191 */ 192static void 193pdcspath_store(struct pdcspath_entry *entry) 194{ 195 struct device_path *devpath; 196 197 BUG_ON(!entry); 198 199 devpath = &entry->devpath; 200 201 /* We expect the caller to set the ready flag to 0 if the hardware 202 path struct provided is invalid, so that we know we have to fill it. 203 First case, we don't have a preset hwpath... */ 204 if (!entry->ready) { 205 /* ...but we have a device, map it */ 206 BUG_ON(!entry->dev); 207 device_to_hwpath(entry->dev, (struct hardware_path *)devpath); 208 } 209 /* else, we expect the provided hwpath to be valid. */ 210 211 DPRINTK("%s: store: 0x%p, 0x%p, addr: 0x%lx\n", __func__, 212 entry, devpath, entry->addr); 213 214 /* addr, devpath and count must be word aligned */ 215 if (pdc_stable_write(entry->addr, devpath, sizeof(*devpath)) != PDC_OK) { 216 printk(KERN_ERR "%s: an error occured when writing to PDC.\n" 217 "It is likely that the Stable Storage data has been corrupted.\n" 218 "Please check it carefully upon next reboot.\n", __func__); 219 WARN_ON(1); 220 } 221 222 /* kobject is already registered */ 223 entry->ready = 2; 224 225 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev); 226} 227 228/** 229 * pdcspath_hwpath_read - This function handles hardware path pretty printing. 230 * @entry: An allocated and populated pdscpath_entry struct. 231 * @buf: The output buffer to write to. 232 * 233 * We will call this function to format the output of the hwpath attribute file. 234 */ 235static ssize_t 236pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf) 237{ 238 char *out = buf; 239 struct device_path *devpath; 240 short i; 241 242 if (!entry || !buf) 243 return -EINVAL; 244 245 read_lock(&entry->rw_lock); 246 devpath = &entry->devpath; 247 i = entry->ready; 248 read_unlock(&entry->rw_lock); 249 250 if (!i) /* entry is not ready */ 251 return -ENODATA; 252 253 for (i = 0; i < 6; i++) { 254 if (devpath->bc[i] >= 128) 255 continue; 256 out += sprintf(out, "%u/", (unsigned char)devpath->bc[i]); 257 } 258 out += sprintf(out, "%u\n", (unsigned char)devpath->mod); 259 260 return out - buf; 261} 262 263static ssize_t 264pdcspath_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[count+1], *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 memset(in, 0, count+1); 277 strncpy(in, buf, count); 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.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.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 ret = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 323 WARN_ON(ret); 324 325 write_unlock(&entry->rw_lock); 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 */ 340static ssize_t 341pdcspath_layer_read(struct pdcspath_entry *entry, char *buf) 342{ 343 char *out = buf; 344 struct device_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 366static ssize_t 367pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count) 368{ 369 unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */ 370 unsigned short i; 371 char in[count+1], *temp; 372 373 if (!entry || !buf || !count) 374 return -EINVAL; 375 376 /* We'll use a local copy of buf */ 377 memset(in, 0, count+1); 378 strncpy(in, buf, count); 379 380 /* Let's clean up the target. 0 is a blank pattern */ 381 memset(&layers, 0, sizeof(layers)); 382 383 /* First, pick the first layer */ 384 if (unlikely(!isdigit(*in))) 385 return -EINVAL; 386 layers[0] = simple_strtoul(in, NULL, 10); 387 DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]); 388 389 temp = in; 390 for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) { 391 if (unlikely(!isdigit(*(++temp)))) 392 return -EINVAL; 393 layers[i] = simple_strtoul(temp, NULL, 10); 394 DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]); 395 } 396 397 /* So far so good, let's get in deep */ 398 write_lock(&entry->rw_lock); 399 400 /* First, overwrite the current layers with the new ones, not touching 401 the hardware path. */ 402 memcpy(&entry->devpath.layers, &layers, sizeof(layers)); 403 404 /* Now, dive in. Write back to the hardware */ 405 pdcspath_store(entry); 406 write_unlock(&entry->rw_lock); 407 408 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n", 409 entry->name, buf); 410 411 return count; 412} 413 414/** 415 * pdcspath_attr_show - Generic read function call wrapper. 416 * @kobj: The kobject to get info from. 417 * @attr: The attribute looked upon. 418 * @buf: The output buffer. 419 */ 420static ssize_t 421pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) 422{ 423 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 424 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 425 ssize_t ret = 0; 426 427 if (pdcs_attr->show) 428 ret = pdcs_attr->show(entry, buf); 429 430 return ret; 431} 432 433/** 434 * pdcspath_attr_store - Generic write function call wrapper. 435 * @kobj: The kobject to write info to. 436 * @attr: The attribute to be modified. 437 * @buf: The input buffer. 438 * @count: The size of the buffer. 439 */ 440static ssize_t 441pdcspath_attr_store(struct kobject *kobj, struct attribute *attr, 442 const char *buf, size_t count) 443{ 444 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 445 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 446 ssize_t ret = 0; 447 448 if (!capable(CAP_SYS_ADMIN)) 449 return -EACCES; 450 451 if (pdcs_attr->store) 452 ret = pdcs_attr->store(entry, buf, count); 453 454 return ret; 455} 456 457static const struct sysfs_ops pdcspath_attr_ops = { 458 .show = pdcspath_attr_show, 459 .store = pdcspath_attr_store, 460}; 461 462/* These are the two attributes of any PDC path. */ 463static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write); 464static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write); 465 466static struct attribute *paths_subsys_attrs[] = { 467 &paths_attr_hwpath.attr, 468 &paths_attr_layer.attr, 469 NULL, 470}; 471 472/* Specific kobject type for our PDC paths */ 473static struct kobj_type ktype_pdcspath = { 474 .sysfs_ops = &pdcspath_attr_ops, 475 .default_attrs = paths_subsys_attrs, 476}; 477 478/* We hard define the 4 types of path we expect to find */ 479static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary); 480static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console); 481static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative); 482static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard); 483 484/* An array containing all PDC paths we will deal with */ 485static struct pdcspath_entry *pdcspath_entries[] = { 486 &pdcspath_entry_primary, 487 &pdcspath_entry_alternative, 488 &pdcspath_entry_console, 489 &pdcspath_entry_keyboard, 490 NULL, 491}; 492 493 494/* For more insight of what's going on here, refer to PDC Procedures doc, 495 * Section PDC_STABLE */ 496 497/** 498 * pdcs_size_read - Stable Storage size output. 499 * @buf: The output buffer to write to. 500 */ 501static ssize_t pdcs_size_read(struct kobject *kobj, 502 struct kobj_attribute *attr, 503 char *buf) 504{ 505 char *out = buf; 506 507 if (!buf) 508 return -EINVAL; 509 510 /* show the size of the stable storage */ 511 out += sprintf(out, "%ld\n", pdcs_size); 512 513 return out - buf; 514} 515 516/** 517 * pdcs_auto_read - Stable Storage autoboot/search flag output. 518 * @buf: The output buffer to write to. 519 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 520 */ 521static ssize_t pdcs_auto_read(struct kobject *kobj, 522 struct kobj_attribute *attr, 523 char *buf, int knob) 524{ 525 char *out = buf; 526 struct pdcspath_entry *pathentry; 527 528 if (!buf) 529 return -EINVAL; 530 531 /* Current flags are stored in primary boot path entry */ 532 pathentry = &pdcspath_entry_primary; 533 534 read_lock(&pathentry->rw_lock); 535 out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ? 536 "On" : "Off"); 537 read_unlock(&pathentry->rw_lock); 538 539 return out - buf; 540} 541 542/** 543 * pdcs_autoboot_read - Stable Storage autoboot flag output. 544 * @buf: The output buffer to write to. 545 */ 546static ssize_t pdcs_autoboot_read(struct kobject *kobj, 547 struct kobj_attribute *attr, char *buf) 548{ 549 return pdcs_auto_read(kobj, attr, buf, PF_AUTOBOOT); 550} 551 552/** 553 * pdcs_autosearch_read - Stable Storage autoboot flag output. 554 * @buf: The output buffer to write to. 555 */ 556static ssize_t pdcs_autosearch_read(struct kobject *kobj, 557 struct kobj_attribute *attr, char *buf) 558{ 559 return pdcs_auto_read(kobj, attr, buf, PF_AUTOSEARCH); 560} 561 562/** 563 * pdcs_timer_read - Stable Storage timer count output (in seconds). 564 * @buf: The output buffer to write to. 565 * 566 * The value of the timer field correponds to a number of seconds in powers of 2. 567 */ 568static ssize_t pdcs_timer_read(struct kobject *kobj, 569 struct kobj_attribute *attr, char *buf) 570{ 571 char *out = buf; 572 struct pdcspath_entry *pathentry; 573 574 if (!buf) 575 return -EINVAL; 576 577 /* Current flags are stored in primary boot path entry */ 578 pathentry = &pdcspath_entry_primary; 579 580 /* print the timer value in seconds */ 581 read_lock(&pathentry->rw_lock); 582 out += sprintf(out, "%u\n", (pathentry->devpath.flags & PF_TIMER) ? 583 (1 << (pathentry->devpath.flags & PF_TIMER)) : 0); 584 read_unlock(&pathentry->rw_lock); 585 586 return out - buf; 587} 588 589/** 590 * pdcs_osid_read - Stable Storage OS ID register output. 591 * @buf: The output buffer to write to. 592 */ 593static ssize_t pdcs_osid_read(struct kobject *kobj, 594 struct kobj_attribute *attr, char *buf) 595{ 596 char *out = buf; 597 598 if (!buf) 599 return -EINVAL; 600 601 out += sprintf(out, "%s dependent data (0x%.4x)\n", 602 os_id_to_string(pdcs_osid), pdcs_osid); 603 604 return out - buf; 605} 606 607/** 608 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output. 609 * @buf: The output buffer to write to. 610 * 611 * This can hold 16 bytes of OS-Dependent data. 612 */ 613static ssize_t pdcs_osdep1_read(struct kobject *kobj, 614 struct kobj_attribute *attr, char *buf) 615{ 616 char *out = buf; 617 u32 result[4]; 618 619 if (!buf) 620 return -EINVAL; 621 622 if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK) 623 return -EIO; 624 625 out += sprintf(out, "0x%.8x\n", result[0]); 626 out += sprintf(out, "0x%.8x\n", result[1]); 627 out += sprintf(out, "0x%.8x\n", result[2]); 628 out += sprintf(out, "0x%.8x\n", result[3]); 629 630 return out - buf; 631} 632 633/** 634 * pdcs_diagnostic_read - Stable Storage Diagnostic register output. 635 * @buf: The output buffer to write to. 636 * 637 * I have NFC how to interpret the content of that register ;-). 638 */ 639static ssize_t pdcs_diagnostic_read(struct kobject *kobj, 640 struct kobj_attribute *attr, char *buf) 641{ 642 char *out = buf; 643 u32 result; 644 645 if (!buf) 646 return -EINVAL; 647 648 /* get diagnostic */ 649 if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK) 650 return -EIO; 651 652 out += sprintf(out, "0x%.4x\n", (result >> 16)); 653 654 return out - buf; 655} 656 657/** 658 * pdcs_fastsize_read - Stable Storage FastSize register output. 659 * @buf: The output buffer to write to. 660 * 661 * This register holds the amount of system RAM to be tested during boot sequence. 662 */ 663static ssize_t pdcs_fastsize_read(struct kobject *kobj, 664 struct kobj_attribute *attr, char *buf) 665{ 666 char *out = buf; 667 u32 result; 668 669 if (!buf) 670 return -EINVAL; 671 672 /* get fast-size */ 673 if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK) 674 return -EIO; 675 676 if ((result & 0x0F) < 0x0E) 677 out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256); 678 else 679 out += sprintf(out, "All"); 680 out += sprintf(out, "\n"); 681 682 return out - buf; 683} 684 685/** 686 * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output. 687 * @buf: The output buffer to write to. 688 * 689 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available. 690 */ 691static ssize_t pdcs_osdep2_read(struct kobject *kobj, 692 struct kobj_attribute *attr, char *buf) 693{ 694 char *out = buf; 695 unsigned long size; 696 unsigned short i; 697 u32 result; 698 699 if (unlikely(pdcs_size <= 224)) 700 return -ENODATA; 701 702 size = pdcs_size - 224; 703 704 if (!buf) 705 return -EINVAL; 706 707 for (i=0; i<size; i+=4) { 708 if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result, 709 sizeof(result)) != PDC_OK)) 710 return -EIO; 711 out += sprintf(out, "0x%.8x\n", result); 712 } 713 714 return out - buf; 715} 716 717/** 718 * pdcs_auto_write - This function handles autoboot/search flag modifying. 719 * @buf: The input buffer to read from. 720 * @count: The number of bytes to be read. 721 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 722 * 723 * We will call this function to change the current autoboot flag. 724 * We expect a precise syntax: 725 * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On 726 */ 727static ssize_t pdcs_auto_write(struct kobject *kobj, 728 struct kobj_attribute *attr, const char *buf, 729 size_t count, int knob) 730{ 731 struct pdcspath_entry *pathentry; 732 unsigned char flags; 733 char in[count+1], *temp; 734 char c; 735 736 if (!capable(CAP_SYS_ADMIN)) 737 return -EACCES; 738 739 if (!buf || !count) 740 return -EINVAL; 741 742 /* We'll use a local copy of buf */ 743 memset(in, 0, count+1); 744 strncpy(in, buf, count); 745 746 /* Current flags are stored in primary boot path entry */ 747 pathentry = &pdcspath_entry_primary; 748 749 /* Be nice to the existing flag record */ 750 read_lock(&pathentry->rw_lock); 751 flags = pathentry->devpath.flags; 752 read_unlock(&pathentry->rw_lock); 753 754 DPRINTK("%s: flags before: 0x%X\n", __func__, flags); 755 756 temp = skip_spaces(in); 757 758 c = *temp++ - '0'; 759 if ((c != 0) && (c != 1)) 760 goto parse_error; 761 if (c == 0) 762 flags &= ~knob; 763 else 764 flags |= knob; 765 766 DPRINTK("%s: flags after: 0x%X\n", __func__, flags); 767 768 /* So far so good, let's get in deep */ 769 write_lock(&pathentry->rw_lock); 770 771 /* Change the path entry flags first */ 772 pathentry->devpath.flags = flags; 773 774 /* Now, dive in. Write back to the hardware */ 775 pdcspath_store(pathentry); 776 write_unlock(&pathentry->rw_lock); 777 778 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n", 779 (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch", 780 (flags & knob) ? "On" : "Off"); 781 782 return count; 783 784parse_error: 785 printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__); 786 return -EINVAL; 787} 788 789/** 790 * pdcs_autoboot_write - This function handles autoboot flag modifying. 791 * @buf: The input buffer to read from. 792 * @count: The number of bytes to be read. 793 * 794 * We will call this function to change the current boot flags. 795 * We expect a precise syntax: 796 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 797 */ 798static ssize_t pdcs_autoboot_write(struct kobject *kobj, 799 struct kobj_attribute *attr, 800 const char *buf, size_t count) 801{ 802 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOBOOT); 803} 804 805/** 806 * pdcs_autosearch_write - This function handles autosearch flag modifying. 807 * @buf: The input buffer to read from. 808 * @count: The number of bytes to be read. 809 * 810 * We will call this function to change the current boot flags. 811 * We expect a precise syntax: 812 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 813 */ 814static ssize_t pdcs_autosearch_write(struct kobject *kobj, 815 struct kobj_attribute *attr, 816 const char *buf, size_t count) 817{ 818 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOSEARCH); 819} 820 821/** 822 * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input. 823 * @buf: The input buffer to read from. 824 * @count: The number of bytes to be read. 825 * 826 * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte 827 * write approach. It's up to userspace to deal with it when constructing 828 * its input buffer. 829 */ 830static ssize_t pdcs_osdep1_write(struct kobject *kobj, 831 struct kobj_attribute *attr, 832 const char *buf, size_t count) 833{ 834 u8 in[16]; 835 836 if (!capable(CAP_SYS_ADMIN)) 837 return -EACCES; 838 839 if (!buf || !count) 840 return -EINVAL; 841 842 if (unlikely(pdcs_osid != OS_ID_LINUX)) 843 return -EPERM; 844 845 if (count > 16) 846 return -EMSGSIZE; 847 848 /* We'll use a local copy of buf */ 849 memset(in, 0, 16); 850 memcpy(in, buf, count); 851 852 if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK) 853 return -EIO; 854 855 return count; 856} 857 858/** 859 * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input. 860 * @buf: The input buffer to read from. 861 * @count: The number of bytes to be read. 862 * 863 * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a 864 * byte-by-byte write approach. It's up to userspace to deal with it when 865 * constructing its input buffer. 866 */ 867static ssize_t pdcs_osdep2_write(struct kobject *kobj, 868 struct kobj_attribute *attr, 869 const char *buf, size_t count) 870{ 871 unsigned long size; 872 unsigned short i; 873 u8 in[4]; 874 875 if (!capable(CAP_SYS_ADMIN)) 876 return -EACCES; 877 878 if (!buf || !count) 879 return -EINVAL; 880 881 if (unlikely(pdcs_size <= 224)) 882 return -ENOSYS; 883 884 if (unlikely(pdcs_osid != OS_ID_LINUX)) 885 return -EPERM; 886 887 size = pdcs_size - 224; 888 889 if (count > size) 890 return -EMSGSIZE; 891 892 /* We'll use a local copy of buf */ 893 894 for (i=0; i<count; i+=4) { 895 memset(in, 0, 4); 896 memcpy(in, buf+i, (count-i < 4) ? count-i : 4); 897 if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in, 898 sizeof(in)) != PDC_OK)) 899 return -EIO; 900 } 901 902 return count; 903} 904 905/* The remaining attributes. */ 906static PDCS_ATTR(size, 0444, pdcs_size_read, NULL); 907static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write); 908static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write); 909static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL); 910static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL); 911static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write); 912static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL); 913static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL); 914static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write); 915 916static struct attribute *pdcs_subsys_attrs[] = { 917 &pdcs_attr_size.attr, 918 &pdcs_attr_autoboot.attr, 919 &pdcs_attr_autosearch.attr, 920 &pdcs_attr_timer.attr, 921 &pdcs_attr_osid.attr, 922 &pdcs_attr_osdep1.attr, 923 &pdcs_attr_diagnostic.attr, 924 &pdcs_attr_fastsize.attr, 925 &pdcs_attr_osdep2.attr, 926 NULL, 927}; 928 929static struct attribute_group pdcs_attr_group = { 930 .attrs = pdcs_subsys_attrs, 931}; 932 933static struct kobject *stable_kobj; 934static struct kset *paths_kset; 935 936/** 937 * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage. 938 * 939 * It creates kobjects corresponding to each path entry with nice sysfs 940 * links to the real device. This is where the magic takes place: when 941 * registering the subsystem attributes during module init, each kobject hereby 942 * created will show in the sysfs tree as a folder containing files as defined 943 * by path_subsys_attr[]. 944 */ 945static inline int __init 946pdcs_register_pathentries(void) 947{ 948 unsigned short i; 949 struct pdcspath_entry *entry; 950 int err; 951 952 /* Initialize the entries rw_lock before anything else */ 953 for (i = 0; (entry = pdcspath_entries[i]); i++) 954 rwlock_init(&entry->rw_lock); 955 956 for (i = 0; (entry = pdcspath_entries[i]); i++) { 957 write_lock(&entry->rw_lock); 958 err = pdcspath_fetch(entry); 959 write_unlock(&entry->rw_lock); 960 961 if (err < 0) 962 continue; 963 964 entry->kobj.kset = paths_kset; 965 err = kobject_init_and_add(&entry->kobj, &ktype_pdcspath, NULL, 966 "%s", entry->name); 967 if (err) 968 return err; 969 970 /* kobject is now registered */ 971 write_lock(&entry->rw_lock); 972 entry->ready = 2; 973 974 /* Add a nice symlink to the real device */ 975 if (entry->dev) { 976 err = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 977 WARN_ON(err); 978 } 979 980 write_unlock(&entry->rw_lock); 981 kobject_uevent(&entry->kobj, KOBJ_ADD); 982 } 983 984 return 0; 985} 986 987/** 988 * pdcs_unregister_pathentries - Routine called when unregistering the module. 989 */ 990static inline void 991pdcs_unregister_pathentries(void) 992{ 993 unsigned short i; 994 struct pdcspath_entry *entry; 995 996 for (i = 0; (entry = pdcspath_entries[i]); i++) { 997 read_lock(&entry->rw_lock); 998 if (entry->ready >= 2) 999 kobject_put(&entry->kobj); 1000 read_unlock(&entry->rw_lock); 1001 } 1002} 1003 1004/* 1005 * For now we register the stable subsystem with the firmware subsystem 1006 * and the paths subsystem with the stable subsystem 1007 */ 1008static int __init 1009pdc_stable_init(void) 1010{ 1011 int rc = 0, error = 0; 1012 u32 result; 1013 1014 /* find the size of the stable storage */ 1015 if (pdc_stable_get_size(&pdcs_size) != PDC_OK) 1016 return -ENODEV; 1017 1018 /* make sure we have enough data */ 1019 if (pdcs_size < 96) 1020 return -ENODATA; 1021 1022 printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION); 1023 1024 /* get OSID */ 1025 if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK) 1026 return -EIO; 1027 1028 /* the actual result is 16 bits away */ 1029 pdcs_osid = (u16)(result >> 16); 1030 1031 /* For now we'll register the directory at /sys/firmware/stable */ 1032 stable_kobj = kobject_create_and_add("stable", firmware_kobj); 1033 if (!stable_kobj) { 1034 rc = -ENOMEM; 1035 goto fail_firmreg; 1036 } 1037 1038 /* Don't forget the root entries */ 1039 error = sysfs_create_group(stable_kobj, &pdcs_attr_group); 1040 1041 /* register the paths kset as a child of the stable kset */ 1042 paths_kset = kset_create_and_add("paths", NULL, stable_kobj); 1043 if (!paths_kset) { 1044 rc = -ENOMEM; 1045 goto fail_ksetreg; 1046 } 1047 1048 /* now we create all "files" for the paths kset */ 1049 if ((rc = pdcs_register_pathentries())) 1050 goto fail_pdcsreg; 1051 1052 return rc; 1053 1054fail_pdcsreg: 1055 pdcs_unregister_pathentries(); 1056 kset_unregister(paths_kset); 1057 1058fail_ksetreg: 1059 kobject_put(stable_kobj); 1060 1061fail_firmreg: 1062 printk(KERN_INFO PDCS_PREFIX " bailing out\n"); 1063 return rc; 1064} 1065 1066static void __exit 1067pdc_stable_exit(void) 1068{ 1069 pdcs_unregister_pathentries(); 1070 kset_unregister(paths_kset); 1071 kobject_put(stable_kobj); 1072} 1073 1074 1075module_init(pdc_stable_init); 1076module_exit(pdc_stable_exit); 1077