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 subsys_attribute pdcs_attr_##_name = { \ 124 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \ 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, .owner = THIS_MODULE}, \ 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; 270 271 if (!entry || !buf || !count) 272 return -EINVAL; 273 274 /* We'll use a local copy of buf */ 275 memset(in, 0, count+1); 276 strncpy(in, buf, count); 277 278 /* Let's clean up the target. 0xff is a blank pattern */ 279 memset(&hwpath, 0xff, sizeof(hwpath)); 280 281 /* First, pick the mod field (the last one of the input string) */ 282 if (!(temp = strrchr(in, '/'))) 283 return -EINVAL; 284 285 hwpath.mod = simple_strtoul(temp+1, NULL, 10); 286 in[temp-in] = '\0'; /* truncate the remaining string. just precaution */ 287 DPRINTK("%s: mod: %d\n", __func__, hwpath.mod); 288 289 /* Then, loop for each delimiter, making sure we don't have too many. 290 we write the bc fields in a down-top way. No matter what, we stop 291 before writing the last field. If there are too many fields anyway, 292 then the user is a moron and it'll be caught up later when we'll 293 check the consistency of the given hwpath. */ 294 for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) { 295 hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10); 296 in[temp-in] = '\0'; 297 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]); 298 } 299 300 /* Store the final field */ 301 hwpath.bc[i] = simple_strtoul(in, NULL, 10); 302 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]); 303 304 /* Now we check that the user isn't trying to lure us */ 305 if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) { 306 printk(KERN_WARNING "%s: attempt to set invalid \"%s\" " 307 "hardware path: %s\n", __func__, entry->name, buf); 308 return -EINVAL; 309 } 310 311 /* So far so good, let's get in deep */ 312 write_lock(&entry->rw_lock); 313 entry->ready = 0; 314 entry->dev = dev; 315 316 /* Now, dive in. Write back to the hardware */ 317 pdcspath_store(entry); 318 319 /* Update the symlink to the real device */ 320 sysfs_remove_link(&entry->kobj, "device"); 321 sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 322 write_unlock(&entry->rw_lock); 323 324 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n", 325 entry->name, buf); 326 327 return count; 328} 329 330/** 331 * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing. 332 * @entry: An allocated and populated pdscpath_entry struct. 333 * @buf: The output buffer to write to. 334 * 335 * We will call this function to format the output of the layer attribute file. 336 */ 337static ssize_t 338pdcspath_layer_read(struct pdcspath_entry *entry, char *buf) 339{ 340 char *out = buf; 341 struct device_path *devpath; 342 short i; 343 344 if (!entry || !buf) 345 return -EINVAL; 346 347 read_lock(&entry->rw_lock); 348 devpath = &entry->devpath; 349 i = entry->ready; 350 read_unlock(&entry->rw_lock); 351 352 if (!i) /* entry is not ready */ 353 return -ENODATA; 354 355 for (i = 0; devpath->layers[i] && (likely(i < 6)); i++) 356 out += sprintf(out, "%u ", devpath->layers[i]); 357 358 out += sprintf(out, "\n"); 359 360 return out - buf; 361} 362 363static ssize_t 364pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count) 365{ 366 unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */ 367 unsigned short i; 368 char in[count+1], *temp; 369 370 if (!entry || !buf || !count) 371 return -EINVAL; 372 373 /* We'll use a local copy of buf */ 374 memset(in, 0, count+1); 375 strncpy(in, buf, count); 376 377 /* Let's clean up the target. 0 is a blank pattern */ 378 memset(&layers, 0, sizeof(layers)); 379 380 /* First, pick the first layer */ 381 if (unlikely(!isdigit(*in))) 382 return -EINVAL; 383 layers[0] = simple_strtoul(in, NULL, 10); 384 DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]); 385 386 temp = in; 387 for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) { 388 if (unlikely(!isdigit(*(++temp)))) 389 return -EINVAL; 390 layers[i] = simple_strtoul(temp, NULL, 10); 391 DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]); 392 } 393 394 /* So far so good, let's get in deep */ 395 write_lock(&entry->rw_lock); 396 397 /* First, overwrite the current layers with the new ones, not touching 398 the hardware path. */ 399 memcpy(&entry->devpath.layers, &layers, sizeof(layers)); 400 401 /* Now, dive in. Write back to the hardware */ 402 pdcspath_store(entry); 403 write_unlock(&entry->rw_lock); 404 405 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n", 406 entry->name, buf); 407 408 return count; 409} 410 411/** 412 * pdcspath_attr_show - Generic read function call wrapper. 413 * @kobj: The kobject to get info from. 414 * @attr: The attribute looked upon. 415 * @buf: The output buffer. 416 */ 417static ssize_t 418pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) 419{ 420 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 421 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 422 ssize_t ret = 0; 423 424 if (pdcs_attr->show) 425 ret = pdcs_attr->show(entry, buf); 426 427 return ret; 428} 429 430/** 431 * pdcspath_attr_store - Generic write function call wrapper. 432 * @kobj: The kobject to write info to. 433 * @attr: The attribute to be modified. 434 * @buf: The input buffer. 435 * @count: The size of the buffer. 436 */ 437static ssize_t 438pdcspath_attr_store(struct kobject *kobj, struct attribute *attr, 439 const char *buf, size_t count) 440{ 441 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 442 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 443 ssize_t ret = 0; 444 445 if (!capable(CAP_SYS_ADMIN)) 446 return -EACCES; 447 448 if (pdcs_attr->store) 449 ret = pdcs_attr->store(entry, buf, count); 450 451 return ret; 452} 453 454static struct sysfs_ops pdcspath_attr_ops = { 455 .show = pdcspath_attr_show, 456 .store = pdcspath_attr_store, 457}; 458 459/* These are the two attributes of any PDC path. */ 460static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write); 461static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write); 462 463static struct attribute *paths_subsys_attrs[] = { 464 &paths_attr_hwpath.attr, 465 &paths_attr_layer.attr, 466 NULL, 467}; 468 469/* Specific kobject type for our PDC paths */ 470static struct kobj_type ktype_pdcspath = { 471 .sysfs_ops = &pdcspath_attr_ops, 472 .default_attrs = paths_subsys_attrs, 473}; 474 475/* We hard define the 4 types of path we expect to find */ 476static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary); 477static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console); 478static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative); 479static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard); 480 481/* An array containing all PDC paths we will deal with */ 482static struct pdcspath_entry *pdcspath_entries[] = { 483 &pdcspath_entry_primary, 484 &pdcspath_entry_alternative, 485 &pdcspath_entry_console, 486 &pdcspath_entry_keyboard, 487 NULL, 488}; 489 490 491/* For more insight of what's going on here, refer to PDC Procedures doc, 492 * Section PDC_STABLE */ 493 494/** 495 * pdcs_size_read - Stable Storage size output. 496 * @kset: An allocated and populated struct kset. We don't use it tho. 497 * @buf: The output buffer to write to. 498 */ 499static ssize_t 500pdcs_size_read(struct kset *kset, char *buf) 501{ 502 char *out = buf; 503 504 if (!kset || !buf) 505 return -EINVAL; 506 507 /* show the size of the stable storage */ 508 out += sprintf(out, "%ld\n", pdcs_size); 509 510 return out - buf; 511} 512 513/** 514 * pdcs_auto_read - Stable Storage autoboot/search flag output. 515 * @kset: An allocated and populated struct kset. We don't use it tho. 516 * @buf: The output buffer to write to. 517 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 518 */ 519static ssize_t 520pdcs_auto_read(struct kset *kset, char *buf, int knob) 521{ 522 char *out = buf; 523 struct pdcspath_entry *pathentry; 524 525 if (!kset || !buf) 526 return -EINVAL; 527 528 /* Current flags are stored in primary boot path entry */ 529 pathentry = &pdcspath_entry_primary; 530 531 read_lock(&pathentry->rw_lock); 532 out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ? 533 "On" : "Off"); 534 read_unlock(&pathentry->rw_lock); 535 536 return out - buf; 537} 538 539/** 540 * pdcs_autoboot_read - Stable Storage autoboot flag output. 541 * @kset: An allocated and populated struct kset. We don't use it tho. 542 * @buf: The output buffer to write to. 543 */ 544static inline ssize_t 545pdcs_autoboot_read(struct kset *kset, char *buf) 546{ 547 return pdcs_auto_read(kset, buf, PF_AUTOBOOT); 548} 549 550/** 551 * pdcs_autosearch_read - Stable Storage autoboot flag output. 552 * @kset: An allocated and populated struct kset. We don't use it tho. 553 * @buf: The output buffer to write to. 554 */ 555static inline ssize_t 556pdcs_autosearch_read(struct kset *kset, char *buf) 557{ 558 return pdcs_auto_read(kset, buf, PF_AUTOSEARCH); 559} 560 561/** 562 * pdcs_timer_read - Stable Storage timer count output (in seconds). 563 * @kset: An allocated and populated struct kset. We don't use it tho. 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 569pdcs_timer_read(struct kset *kset, char *buf) 570{ 571 char *out = buf; 572 struct pdcspath_entry *pathentry; 573 574 if (!kset || !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 * @kset: An allocated and populated struct kset. We don't use it tho. 592 * @buf: The output buffer to write to. 593 */ 594static ssize_t 595pdcs_osid_read(struct kset *kset, char *buf) 596{ 597 char *out = buf; 598 599 if (!kset || !buf) 600 return -EINVAL; 601 602 out += sprintf(out, "%s dependent data (0x%.4x)\n", 603 os_id_to_string(pdcs_osid), pdcs_osid); 604 605 return out - buf; 606} 607 608/** 609 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output. 610 * @kset: An allocated and populated struct kset. We don't use it tho. 611 * @buf: The output buffer to write to. 612 * 613 * This can hold 16 bytes of OS-Dependent data. 614 */ 615static ssize_t 616pdcs_osdep1_read(struct kset *kset, char *buf) 617{ 618 char *out = buf; 619 u32 result[4]; 620 621 if (!kset || !buf) 622 return -EINVAL; 623 624 if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK) 625 return -EIO; 626 627 out += sprintf(out, "0x%.8x\n", result[0]); 628 out += sprintf(out, "0x%.8x\n", result[1]); 629 out += sprintf(out, "0x%.8x\n", result[2]); 630 out += sprintf(out, "0x%.8x\n", result[3]); 631 632 return out - buf; 633} 634 635/** 636 * pdcs_diagnostic_read - Stable Storage Diagnostic register output. 637 * @kset: An allocated and populated struct kset. We don't use it tho. 638 * @buf: The output buffer to write to. 639 * 640 * I have NFC how to interpret the content of that register ;-). 641 */ 642static ssize_t 643pdcs_diagnostic_read(struct kset *kset, char *buf) 644{ 645 char *out = buf; 646 u32 result; 647 648 if (!kset || !buf) 649 return -EINVAL; 650 651 /* get diagnostic */ 652 if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK) 653 return -EIO; 654 655 out += sprintf(out, "0x%.4x\n", (result >> 16)); 656 657 return out - buf; 658} 659 660/** 661 * pdcs_fastsize_read - Stable Storage FastSize register output. 662 * @kset: An allocated and populated struct kset. We don't use it tho. 663 * @buf: The output buffer to write to. 664 * 665 * This register holds the amount of system RAM to be tested during boot sequence. 666 */ 667static ssize_t 668pdcs_fastsize_read(struct kset *kset, char *buf) 669{ 670 char *out = buf; 671 u32 result; 672 673 if (!kset || !buf) 674 return -EINVAL; 675 676 /* get fast-size */ 677 if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK) 678 return -EIO; 679 680 if ((result & 0x0F) < 0x0E) 681 out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256); 682 else 683 out += sprintf(out, "All"); 684 out += sprintf(out, "\n"); 685 686 return out - buf; 687} 688 689/** 690 * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output. 691 * @kset: An allocated and populated struct kset. We don't use it tho. 692 * @buf: The output buffer to write to. 693 * 694 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available. 695 */ 696static ssize_t 697pdcs_osdep2_read(struct kset *kset, char *buf) 698{ 699 char *out = buf; 700 unsigned long size; 701 unsigned short i; 702 u32 result; 703 704 if (unlikely(pdcs_size <= 224)) 705 return -ENODATA; 706 707 size = pdcs_size - 224; 708 709 if (!kset || !buf) 710 return -EINVAL; 711 712 for (i=0; i<size; i+=4) { 713 if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result, 714 sizeof(result)) != PDC_OK)) 715 return -EIO; 716 out += sprintf(out, "0x%.8x\n", result); 717 } 718 719 return out - buf; 720} 721 722/** 723 * pdcs_auto_write - This function handles autoboot/search flag modifying. 724 * @kset: An allocated and populated struct kset. We don't use it tho. 725 * @buf: The input buffer to read from. 726 * @count: The number of bytes to be read. 727 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 728 * 729 * We will call this function to change the current autoboot flag. 730 * We expect a precise syntax: 731 * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On 732 */ 733static ssize_t 734pdcs_auto_write(struct kset *kset, const char *buf, size_t count, int knob) 735{ 736 struct pdcspath_entry *pathentry; 737 unsigned char flags; 738 char in[count+1], *temp; 739 char c; 740 741 if (!capable(CAP_SYS_ADMIN)) 742 return -EACCES; 743 744 if (!kset || !buf || !count) 745 return -EINVAL; 746 747 /* We'll use a local copy of buf */ 748 memset(in, 0, count+1); 749 strncpy(in, buf, count); 750 751 /* Current flags are stored in primary boot path entry */ 752 pathentry = &pdcspath_entry_primary; 753 754 /* Be nice to the existing flag record */ 755 read_lock(&pathentry->rw_lock); 756 flags = pathentry->devpath.flags; 757 read_unlock(&pathentry->rw_lock); 758 759 DPRINTK("%s: flags before: 0x%X\n", __func__, flags); 760 761 temp = in; 762 763 while (*temp && isspace(*temp)) 764 temp++; 765 766 c = *temp++ - '0'; 767 if ((c != 0) && (c != 1)) 768 goto parse_error; 769 if (c == 0) 770 flags &= ~knob; 771 else 772 flags |= knob; 773 774 DPRINTK("%s: flags after: 0x%X\n", __func__, flags); 775 776 /* So far so good, let's get in deep */ 777 write_lock(&pathentry->rw_lock); 778 779 /* Change the path entry flags first */ 780 pathentry->devpath.flags = flags; 781 782 /* Now, dive in. Write back to the hardware */ 783 pdcspath_store(pathentry); 784 write_unlock(&pathentry->rw_lock); 785 786 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n", 787 (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch", 788 (flags & knob) ? "On" : "Off"); 789 790 return count; 791 792parse_error: 793 printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__); 794 return -EINVAL; 795} 796 797/** 798 * pdcs_autoboot_write - This function handles autoboot flag modifying. 799 * @kset: An allocated and populated struct kset. We don't use it tho. 800 * @buf: The input buffer to read from. 801 * @count: The number of bytes to be read. 802 * 803 * We will call this function to change the current boot flags. 804 * We expect a precise syntax: 805 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 806 */ 807static inline ssize_t 808pdcs_autoboot_write(struct kset *kset, const char *buf, size_t count) 809{ 810 return pdcs_auto_write(kset, buf, count, PF_AUTOBOOT); 811} 812 813/** 814 * pdcs_autosearch_write - This function handles autosearch flag modifying. 815 * @kset: An allocated and populated struct kset. We don't use it tho. 816 * @buf: The input buffer to read from. 817 * @count: The number of bytes to be read. 818 * 819 * We will call this function to change the current boot flags. 820 * We expect a precise syntax: 821 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 822 */ 823static inline ssize_t 824pdcs_autosearch_write(struct kset *kset, const char *buf, size_t count) 825{ 826 return pdcs_auto_write(kset, buf, count, PF_AUTOSEARCH); 827} 828 829/** 830 * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input. 831 * @kset: An allocated and populated struct kset. We don't use it tho. 832 * @buf: The input buffer to read from. 833 * @count: The number of bytes to be read. 834 * 835 * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte 836 * write approach. It's up to userspace to deal with it when constructing 837 * its input buffer. 838 */ 839static ssize_t 840pdcs_osdep1_write(struct kset *kset, const char *buf, size_t count) 841{ 842 u8 in[16]; 843 844 if (!capable(CAP_SYS_ADMIN)) 845 return -EACCES; 846 847 if (!kset || !buf || !count) 848 return -EINVAL; 849 850 if (unlikely(pdcs_osid != OS_ID_LINUX)) 851 return -EPERM; 852 853 if (count > 16) 854 return -EMSGSIZE; 855 856 /* We'll use a local copy of buf */ 857 memset(in, 0, 16); 858 memcpy(in, buf, count); 859 860 if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK) 861 return -EIO; 862 863 return count; 864} 865 866/** 867 * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input. 868 * @kset: An allocated and populated struct kset. We don't use it tho. 869 * @buf: The input buffer to read from. 870 * @count: The number of bytes to be read. 871 * 872 * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a 873 * byte-by-byte write approach. It's up to userspace to deal with it when 874 * constructing its input buffer. 875 */ 876static ssize_t 877pdcs_osdep2_write(struct kset *kset, const char *buf, size_t count) 878{ 879 unsigned long size; 880 unsigned short i; 881 u8 in[4]; 882 883 if (!capable(CAP_SYS_ADMIN)) 884 return -EACCES; 885 886 if (!kset || !buf || !count) 887 return -EINVAL; 888 889 if (unlikely(pdcs_size <= 224)) 890 return -ENOSYS; 891 892 if (unlikely(pdcs_osid != OS_ID_LINUX)) 893 return -EPERM; 894 895 size = pdcs_size - 224; 896 897 if (count > size) 898 return -EMSGSIZE; 899 900 /* We'll use a local copy of buf */ 901 902 for (i=0; i<count; i+=4) { 903 memset(in, 0, 4); 904 memcpy(in, buf+i, (count-i < 4) ? count-i : 4); 905 if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in, 906 sizeof(in)) != PDC_OK)) 907 return -EIO; 908 } 909 910 return count; 911} 912 913/* The remaining attributes. */ 914static PDCS_ATTR(size, 0444, pdcs_size_read, NULL); 915static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write); 916static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write); 917static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL); 918static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL); 919static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write); 920static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL); 921static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL); 922static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write); 923 924static struct subsys_attribute *pdcs_subsys_attrs[] = { 925 &pdcs_attr_size, 926 &pdcs_attr_autoboot, 927 &pdcs_attr_autosearch, 928 &pdcs_attr_timer, 929 &pdcs_attr_osid, 930 &pdcs_attr_osdep1, 931 &pdcs_attr_diagnostic, 932 &pdcs_attr_fastsize, 933 &pdcs_attr_osdep2, 934 NULL, 935}; 936 937static decl_subsys(paths, &ktype_pdcspath, NULL); 938static decl_subsys(stable, NULL, NULL); 939 940/** 941 * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage. 942 * 943 * It creates kobjects corresponding to each path entry with nice sysfs 944 * links to the real device. This is where the magic takes place: when 945 * registering the subsystem attributes during module init, each kobject hereby 946 * created will show in the sysfs tree as a folder containing files as defined 947 * by path_subsys_attr[]. 948 */ 949static inline int __init 950pdcs_register_pathentries(void) 951{ 952 unsigned short i; 953 struct pdcspath_entry *entry; 954 int err; 955 956 /* Initialize the entries rw_lock before anything else */ 957 for (i = 0; (entry = pdcspath_entries[i]); i++) 958 rwlock_init(&entry->rw_lock); 959 960 for (i = 0; (entry = pdcspath_entries[i]); i++) { 961 write_lock(&entry->rw_lock); 962 err = pdcspath_fetch(entry); 963 write_unlock(&entry->rw_lock); 964 965 if (err < 0) 966 continue; 967 968 if ((err = kobject_set_name(&entry->kobj, "%s", entry->name))) 969 return err; 970 kobj_set_kset_s(entry, paths_subsys); 971 if ((err = kobject_register(&entry->kobj))) 972 return err; 973 974 /* kobject is now registered */ 975 write_lock(&entry->rw_lock); 976 entry->ready = 2; 977 978 /* Add a nice symlink to the real device */ 979 if (entry->dev) 980 sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 981 982 write_unlock(&entry->rw_lock); 983 } 984 985 return 0; 986} 987 988/** 989 * pdcs_unregister_pathentries - Routine called when unregistering the module. 990 */ 991static inline void 992pdcs_unregister_pathentries(void) 993{ 994 unsigned short i; 995 struct pdcspath_entry *entry; 996 997 for (i = 0; (entry = pdcspath_entries[i]); i++) { 998 read_lock(&entry->rw_lock); 999 if (entry->ready >= 2) 1000 kobject_unregister(&entry->kobj); 1001 read_unlock(&entry->rw_lock); 1002 } 1003} 1004 1005/* 1006 * For now we register the stable subsystem with the firmware subsystem 1007 * and the paths subsystem with the stable subsystem 1008 */ 1009static int __init 1010pdc_stable_init(void) 1011{ 1012 struct subsys_attribute *attr; 1013 int i, rc = 0, error = 0; 1014 u32 result; 1015 1016 /* find the size of the stable storage */ 1017 if (pdc_stable_get_size(&pdcs_size) != PDC_OK) 1018 return -ENODEV; 1019 1020 /* make sure we have enough data */ 1021 if (pdcs_size < 96) 1022 return -ENODATA; 1023 1024 printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION); 1025 1026 /* get OSID */ 1027 if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK) 1028 return -EIO; 1029 1030 /* the actual result is 16 bits away */ 1031 pdcs_osid = (u16)(result >> 16); 1032 1033 /* For now we'll register the stable subsys within this driver */ 1034 if ((rc = firmware_register(&stable_subsys))) 1035 goto fail_firmreg; 1036 1037 /* Don't forget the root entries */ 1038 for (i = 0; (attr = pdcs_subsys_attrs[i]) && !error; i++) 1039 if (attr->show) 1040 error = subsys_create_file(&stable_subsys, attr); 1041 1042 /* register the paths subsys as a subsystem of stable subsys */ 1043 kobj_set_kset_s(&paths_subsys, stable_subsys); 1044 if ((rc = subsystem_register(&paths_subsys))) 1045 goto fail_subsysreg; 1046 1047 /* now we create all "files" for the paths subsys */ 1048 if ((rc = pdcs_register_pathentries())) 1049 goto fail_pdcsreg; 1050 1051 return rc; 1052 1053fail_pdcsreg: 1054 pdcs_unregister_pathentries(); 1055 subsystem_unregister(&paths_subsys); 1056 1057fail_subsysreg: 1058 firmware_unregister(&stable_subsys); 1059 1060fail_firmreg: 1061 printk(KERN_INFO PDCS_PREFIX " bailing out\n"); 1062 return rc; 1063} 1064 1065static void __exit 1066pdc_stable_exit(void) 1067{ 1068 pdcs_unregister_pathentries(); 1069 subsystem_unregister(&paths_subsys); 1070 1071 firmware_unregister(&stable_subsys); 1072} 1073 1074 1075module_init(pdc_stable_init); 1076module_exit(pdc_stable_exit); 1077