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 87 MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>"); 88 MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data"); 89 MODULE_LICENSE("GPL"); 90 MODULE_VERSION(PDCS_VERSION); 91 92 /* holds Stable Storage size. Initialized once and for all, no lock needed */ 93 static unsigned long pdcs_size __read_mostly; 94 95 /* holds OS ID. Initialized once and for all, hopefully to 0x0006 */ 96 static u16 pdcs_osid __read_mostly; 97 98 /* This struct defines what we need to deal with a parisc pdc path entry */ 99 struct 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 }; 108 109 struct 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) \ 116 struct 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) \ 123 struct 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) \ 130 struct 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 facilities. 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 */ 151 static int 152 pdcspath_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 */ 192 static void 193 pdcspath_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 occurred 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 */ 235 static ssize_t 236 pdcspath_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 } 262 263 /** 264 * pdcspath_hwpath_write - This function handles hardware path modifying. 265 * @entry: An allocated and populated pdscpath_entry struct. 266 * @buf: The input buffer to read from. 267 * @count: The number of bytes to be read. 268 * 269 * We will call this function to change the current hardware path. 270 * Hardware paths are to be given '/'-delimited, without brackets. 271 * We make sure that the provided path actually maps to an existing 272 * device, BUT nothing would prevent some foolish user to set the path to some 273 * PCI bridge or even a CPU... 274 * A better work around would be to make sure we are at the end of a device tree 275 * for instance, but it would be IMHO beyond the simple scope of that driver. 276 * The aim is to provide a facility. Data correctness is left to userland. 277 */ 278 static ssize_t 279 pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t count) 280 { 281 struct hardware_path hwpath; 282 unsigned short i; 283 char in[count+1], *temp; 284 struct device *dev; 285 int ret; 286 287 if (!entry || !buf || !count) 288 return -EINVAL; 289 290 /* We'll use a local copy of buf */ 291 memset(in, 0, count+1); 292 strncpy(in, buf, count); 293 294 /* Let's clean up the target. 0xff is a blank pattern */ 295 memset(&hwpath, 0xff, sizeof(hwpath)); 296 297 /* First, pick the mod field (the last one of the input string) */ 298 if (!(temp = strrchr(in, '/'))) 299 return -EINVAL; 300 301 hwpath.mod = simple_strtoul(temp+1, NULL, 10); 302 in[temp-in] = '\0'; /* truncate the remaining string. just precaution */ 303 DPRINTK("%s: mod: %d\n", __func__, hwpath.mod); 304 305 /* Then, loop for each delimiter, making sure we don't have too many. 306 we write the bc fields in a down-top way. No matter what, we stop 307 before writing the last field. If there are too many fields anyway, 308 then the user is a moron and it'll be caught up later when we'll 309 check the consistency of the given hwpath. */ 310 for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) { 311 hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10); 312 in[temp-in] = '\0'; 313 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]); 314 } 315 316 /* Store the final field */ 317 hwpath.bc[i] = simple_strtoul(in, NULL, 10); 318 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]); 319 320 /* Now we check that the user isn't trying to lure us */ 321 if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) { 322 printk(KERN_WARNING "%s: attempt to set invalid \"%s\" " 323 "hardware path: %s\n", __func__, entry->name, buf); 324 return -EINVAL; 325 } 326 327 /* So far so good, let's get in deep */ 328 write_lock(&entry->rw_lock); 329 entry->ready = 0; 330 entry->dev = dev; 331 332 /* Now, dive in. Write back to the hardware */ 333 pdcspath_store(entry); 334 335 /* Update the symlink to the real device */ 336 sysfs_remove_link(&entry->kobj, "device"); 337 ret = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 338 WARN_ON(ret); 339 340 write_unlock(&entry->rw_lock); 341 342 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n", 343 entry->name, buf); 344 345 return count; 346 } 347 348 /** 349 * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing. 350 * @entry: An allocated and populated pdscpath_entry struct. 351 * @buf: The output buffer to write to. 352 * 353 * We will call this function to format the output of the layer attribute file. 354 */ 355 static ssize_t 356 pdcspath_layer_read(struct pdcspath_entry *entry, char *buf) 357 { 358 char *out = buf; 359 struct device_path *devpath; 360 short i; 361 362 if (!entry || !buf) 363 return -EINVAL; 364 365 read_lock(&entry->rw_lock); 366 devpath = &entry->devpath; 367 i = entry->ready; 368 read_unlock(&entry->rw_lock); 369 370 if (!i) /* entry is not ready */ 371 return -ENODATA; 372 373 for (i = 0; i < 6 && devpath->layers[i]; i++) 374 out += sprintf(out, "%u ", devpath->layers[i]); 375 376 out += sprintf(out, "\n"); 377 378 return out - buf; 379 } 380 381 /** 382 * pdcspath_layer_write - This function handles extended layer modifying. 383 * @entry: An allocated and populated pdscpath_entry struct. 384 * @buf: The input buffer to read from. 385 * @count: The number of bytes to be read. 386 * 387 * We will call this function to change the current layer value. 388 * Layers are to be given '.'-delimited, without brackets. 389 * XXX beware we are far less checky WRT input data provided than for hwpath. 390 * Potential harm can be done, since there's no way to check the validity of 391 * the layer fields. 392 */ 393 static ssize_t 394 pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count) 395 { 396 unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */ 397 unsigned short i; 398 char in[count+1], *temp; 399 400 if (!entry || !buf || !count) 401 return -EINVAL; 402 403 /* We'll use a local copy of buf */ 404 memset(in, 0, count+1); 405 strncpy(in, buf, count); 406 407 /* Let's clean up the target. 0 is a blank pattern */ 408 memset(&layers, 0, sizeof(layers)); 409 410 /* First, pick the first layer */ 411 if (unlikely(!isdigit(*in))) 412 return -EINVAL; 413 layers[0] = simple_strtoul(in, NULL, 10); 414 DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]); 415 416 temp = in; 417 for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) { 418 if (unlikely(!isdigit(*(++temp)))) 419 return -EINVAL; 420 layers[i] = simple_strtoul(temp, NULL, 10); 421 DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]); 422 } 423 424 /* So far so good, let's get in deep */ 425 write_lock(&entry->rw_lock); 426 427 /* First, overwrite the current layers with the new ones, not touching 428 the hardware path. */ 429 memcpy(&entry->devpath.layers, &layers, sizeof(layers)); 430 431 /* Now, dive in. Write back to the hardware */ 432 pdcspath_store(entry); 433 write_unlock(&entry->rw_lock); 434 435 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n", 436 entry->name, buf); 437 438 return count; 439 } 440 441 /** 442 * pdcspath_attr_show - Generic read function call wrapper. 443 * @kobj: The kobject to get info from. 444 * @attr: The attribute looked upon. 445 * @buf: The output buffer. 446 */ 447 static ssize_t 448 pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) 449 { 450 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 451 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 452 ssize_t ret = 0; 453 454 if (pdcs_attr->show) 455 ret = pdcs_attr->show(entry, buf); 456 457 return ret; 458 } 459 460 /** 461 * pdcspath_attr_store - Generic write function call wrapper. 462 * @kobj: The kobject to write info to. 463 * @attr: The attribute to be modified. 464 * @buf: The input buffer. 465 * @count: The size of the buffer. 466 */ 467 static ssize_t 468 pdcspath_attr_store(struct kobject *kobj, struct attribute *attr, 469 const char *buf, size_t count) 470 { 471 struct pdcspath_entry *entry = to_pdcspath_entry(kobj); 472 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); 473 ssize_t ret = 0; 474 475 if (!capable(CAP_SYS_ADMIN)) 476 return -EACCES; 477 478 if (pdcs_attr->store) 479 ret = pdcs_attr->store(entry, buf, count); 480 481 return ret; 482 } 483 484 static const struct sysfs_ops pdcspath_attr_ops = { 485 .show = pdcspath_attr_show, 486 .store = pdcspath_attr_store, 487 }; 488 489 /* These are the two attributes of any PDC path. */ 490 static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write); 491 static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write); 492 493 static struct attribute *paths_subsys_attrs[] = { 494 &paths_attr_hwpath.attr, 495 &paths_attr_layer.attr, 496 NULL, 497 }; 498 499 /* Specific kobject type for our PDC paths */ 500 static struct kobj_type ktype_pdcspath = { 501 .sysfs_ops = &pdcspath_attr_ops, 502 .default_attrs = paths_subsys_attrs, 503 }; 504 505 /* We hard define the 4 types of path we expect to find */ 506 static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary); 507 static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console); 508 static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative); 509 static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard); 510 511 /* An array containing all PDC paths we will deal with */ 512 static struct pdcspath_entry *pdcspath_entries[] = { 513 &pdcspath_entry_primary, 514 &pdcspath_entry_alternative, 515 &pdcspath_entry_console, 516 &pdcspath_entry_keyboard, 517 NULL, 518 }; 519 520 521 /* For more insight of what's going on here, refer to PDC Procedures doc, 522 * Section PDC_STABLE */ 523 524 /** 525 * pdcs_size_read - Stable Storage size output. 526 * @buf: The output buffer to write to. 527 */ 528 static ssize_t pdcs_size_read(struct kobject *kobj, 529 struct kobj_attribute *attr, 530 char *buf) 531 { 532 char *out = buf; 533 534 if (!buf) 535 return -EINVAL; 536 537 /* show the size of the stable storage */ 538 out += sprintf(out, "%ld\n", pdcs_size); 539 540 return out - buf; 541 } 542 543 /** 544 * pdcs_auto_read - Stable Storage autoboot/search flag output. 545 * @buf: The output buffer to write to. 546 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 547 */ 548 static ssize_t pdcs_auto_read(struct kobject *kobj, 549 struct kobj_attribute *attr, 550 char *buf, int knob) 551 { 552 char *out = buf; 553 struct pdcspath_entry *pathentry; 554 555 if (!buf) 556 return -EINVAL; 557 558 /* Current flags are stored in primary boot path entry */ 559 pathentry = &pdcspath_entry_primary; 560 561 read_lock(&pathentry->rw_lock); 562 out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ? 563 "On" : "Off"); 564 read_unlock(&pathentry->rw_lock); 565 566 return out - buf; 567 } 568 569 /** 570 * pdcs_autoboot_read - Stable Storage autoboot flag output. 571 * @buf: The output buffer to write to. 572 */ 573 static ssize_t pdcs_autoboot_read(struct kobject *kobj, 574 struct kobj_attribute *attr, char *buf) 575 { 576 return pdcs_auto_read(kobj, attr, buf, PF_AUTOBOOT); 577 } 578 579 /** 580 * pdcs_autosearch_read - Stable Storage autoboot flag output. 581 * @buf: The output buffer to write to. 582 */ 583 static ssize_t pdcs_autosearch_read(struct kobject *kobj, 584 struct kobj_attribute *attr, char *buf) 585 { 586 return pdcs_auto_read(kobj, attr, buf, PF_AUTOSEARCH); 587 } 588 589 /** 590 * pdcs_timer_read - Stable Storage timer count output (in seconds). 591 * @buf: The output buffer to write to. 592 * 593 * The value of the timer field correponds to a number of seconds in powers of 2. 594 */ 595 static ssize_t pdcs_timer_read(struct kobject *kobj, 596 struct kobj_attribute *attr, char *buf) 597 { 598 char *out = buf; 599 struct pdcspath_entry *pathentry; 600 601 if (!buf) 602 return -EINVAL; 603 604 /* Current flags are stored in primary boot path entry */ 605 pathentry = &pdcspath_entry_primary; 606 607 /* print the timer value in seconds */ 608 read_lock(&pathentry->rw_lock); 609 out += sprintf(out, "%u\n", (pathentry->devpath.flags & PF_TIMER) ? 610 (1 << (pathentry->devpath.flags & PF_TIMER)) : 0); 611 read_unlock(&pathentry->rw_lock); 612 613 return out - buf; 614 } 615 616 /** 617 * pdcs_osid_read - Stable Storage OS ID register output. 618 * @buf: The output buffer to write to. 619 */ 620 static ssize_t pdcs_osid_read(struct kobject *kobj, 621 struct kobj_attribute *attr, char *buf) 622 { 623 char *out = buf; 624 625 if (!buf) 626 return -EINVAL; 627 628 out += sprintf(out, "%s dependent data (0x%.4x)\n", 629 os_id_to_string(pdcs_osid), pdcs_osid); 630 631 return out - buf; 632 } 633 634 /** 635 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output. 636 * @buf: The output buffer to write to. 637 * 638 * This can hold 16 bytes of OS-Dependent data. 639 */ 640 static ssize_t pdcs_osdep1_read(struct kobject *kobj, 641 struct kobj_attribute *attr, char *buf) 642 { 643 char *out = buf; 644 u32 result[4]; 645 646 if (!buf) 647 return -EINVAL; 648 649 if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK) 650 return -EIO; 651 652 out += sprintf(out, "0x%.8x\n", result[0]); 653 out += sprintf(out, "0x%.8x\n", result[1]); 654 out += sprintf(out, "0x%.8x\n", result[2]); 655 out += sprintf(out, "0x%.8x\n", result[3]); 656 657 return out - buf; 658 } 659 660 /** 661 * pdcs_diagnostic_read - Stable Storage Diagnostic register output. 662 * @buf: The output buffer to write to. 663 * 664 * I have NFC how to interpret the content of that register ;-). 665 */ 666 static ssize_t pdcs_diagnostic_read(struct kobject *kobj, 667 struct kobj_attribute *attr, char *buf) 668 { 669 char *out = buf; 670 u32 result; 671 672 if (!buf) 673 return -EINVAL; 674 675 /* get diagnostic */ 676 if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK) 677 return -EIO; 678 679 out += sprintf(out, "0x%.4x\n", (result >> 16)); 680 681 return out - buf; 682 } 683 684 /** 685 * pdcs_fastsize_read - Stable Storage FastSize register output. 686 * @buf: The output buffer to write to. 687 * 688 * This register holds the amount of system RAM to be tested during boot sequence. 689 */ 690 static ssize_t pdcs_fastsize_read(struct kobject *kobj, 691 struct kobj_attribute *attr, char *buf) 692 { 693 char *out = buf; 694 u32 result; 695 696 if (!buf) 697 return -EINVAL; 698 699 /* get fast-size */ 700 if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK) 701 return -EIO; 702 703 if ((result & 0x0F) < 0x0E) 704 out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256); 705 else 706 out += sprintf(out, "All"); 707 out += sprintf(out, "\n"); 708 709 return out - buf; 710 } 711 712 /** 713 * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output. 714 * @buf: The output buffer to write to. 715 * 716 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available. 717 */ 718 static ssize_t pdcs_osdep2_read(struct kobject *kobj, 719 struct kobj_attribute *attr, char *buf) 720 { 721 char *out = buf; 722 unsigned long size; 723 unsigned short i; 724 u32 result; 725 726 if (unlikely(pdcs_size <= 224)) 727 return -ENODATA; 728 729 size = pdcs_size - 224; 730 731 if (!buf) 732 return -EINVAL; 733 734 for (i=0; i<size; i+=4) { 735 if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result, 736 sizeof(result)) != PDC_OK)) 737 return -EIO; 738 out += sprintf(out, "0x%.8x\n", result); 739 } 740 741 return out - buf; 742 } 743 744 /** 745 * pdcs_auto_write - This function handles autoboot/search flag modifying. 746 * @buf: The input buffer to read from. 747 * @count: The number of bytes to be read. 748 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag 749 * 750 * We will call this function to change the current autoboot flag. 751 * We expect a precise syntax: 752 * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On 753 */ 754 static ssize_t pdcs_auto_write(struct kobject *kobj, 755 struct kobj_attribute *attr, const char *buf, 756 size_t count, int knob) 757 { 758 struct pdcspath_entry *pathentry; 759 unsigned char flags; 760 char in[count+1], *temp; 761 char c; 762 763 if (!capable(CAP_SYS_ADMIN)) 764 return -EACCES; 765 766 if (!buf || !count) 767 return -EINVAL; 768 769 /* We'll use a local copy of buf */ 770 memset(in, 0, count+1); 771 strncpy(in, buf, count); 772 773 /* Current flags are stored in primary boot path entry */ 774 pathentry = &pdcspath_entry_primary; 775 776 /* Be nice to the existing flag record */ 777 read_lock(&pathentry->rw_lock); 778 flags = pathentry->devpath.flags; 779 read_unlock(&pathentry->rw_lock); 780 781 DPRINTK("%s: flags before: 0x%X\n", __func__, flags); 782 783 temp = skip_spaces(in); 784 785 c = *temp++ - '0'; 786 if ((c != 0) && (c != 1)) 787 goto parse_error; 788 if (c == 0) 789 flags &= ~knob; 790 else 791 flags |= knob; 792 793 DPRINTK("%s: flags after: 0x%X\n", __func__, flags); 794 795 /* So far so good, let's get in deep */ 796 write_lock(&pathentry->rw_lock); 797 798 /* Change the path entry flags first */ 799 pathentry->devpath.flags = flags; 800 801 /* Now, dive in. Write back to the hardware */ 802 pdcspath_store(pathentry); 803 write_unlock(&pathentry->rw_lock); 804 805 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n", 806 (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch", 807 (flags & knob) ? "On" : "Off"); 808 809 return count; 810 811 parse_error: 812 printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__); 813 return -EINVAL; 814 } 815 816 /** 817 * pdcs_autoboot_write - This function handles autoboot flag modifying. 818 * @buf: The input buffer to read from. 819 * @count: The number of bytes to be read. 820 * 821 * We will call this function to change the current boot flags. 822 * We expect a precise syntax: 823 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 824 */ 825 static ssize_t pdcs_autoboot_write(struct kobject *kobj, 826 struct kobj_attribute *attr, 827 const char *buf, size_t count) 828 { 829 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOBOOT); 830 } 831 832 /** 833 * pdcs_autosearch_write - This function handles autosearch flag modifying. 834 * @buf: The input buffer to read from. 835 * @count: The number of bytes to be read. 836 * 837 * We will call this function to change the current boot flags. 838 * We expect a precise syntax: 839 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On 840 */ 841 static ssize_t pdcs_autosearch_write(struct kobject *kobj, 842 struct kobj_attribute *attr, 843 const char *buf, size_t count) 844 { 845 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOSEARCH); 846 } 847 848 /** 849 * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input. 850 * @buf: The input buffer to read from. 851 * @count: The number of bytes to be read. 852 * 853 * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte 854 * write approach. It's up to userspace to deal with it when constructing 855 * its input buffer. 856 */ 857 static ssize_t pdcs_osdep1_write(struct kobject *kobj, 858 struct kobj_attribute *attr, 859 const char *buf, size_t count) 860 { 861 u8 in[16]; 862 863 if (!capable(CAP_SYS_ADMIN)) 864 return -EACCES; 865 866 if (!buf || !count) 867 return -EINVAL; 868 869 if (unlikely(pdcs_osid != OS_ID_LINUX)) 870 return -EPERM; 871 872 if (count > 16) 873 return -EMSGSIZE; 874 875 /* We'll use a local copy of buf */ 876 memset(in, 0, 16); 877 memcpy(in, buf, count); 878 879 if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK) 880 return -EIO; 881 882 return count; 883 } 884 885 /** 886 * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input. 887 * @buf: The input buffer to read from. 888 * @count: The number of bytes to be read. 889 * 890 * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a 891 * byte-by-byte write approach. It's up to userspace to deal with it when 892 * constructing its input buffer. 893 */ 894 static ssize_t pdcs_osdep2_write(struct kobject *kobj, 895 struct kobj_attribute *attr, 896 const char *buf, size_t count) 897 { 898 unsigned long size; 899 unsigned short i; 900 u8 in[4]; 901 902 if (!capable(CAP_SYS_ADMIN)) 903 return -EACCES; 904 905 if (!buf || !count) 906 return -EINVAL; 907 908 if (unlikely(pdcs_size <= 224)) 909 return -ENOSYS; 910 911 if (unlikely(pdcs_osid != OS_ID_LINUX)) 912 return -EPERM; 913 914 size = pdcs_size - 224; 915 916 if (count > size) 917 return -EMSGSIZE; 918 919 /* We'll use a local copy of buf */ 920 921 for (i=0; i<count; i+=4) { 922 memset(in, 0, 4); 923 memcpy(in, buf+i, (count-i < 4) ? count-i : 4); 924 if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in, 925 sizeof(in)) != PDC_OK)) 926 return -EIO; 927 } 928 929 return count; 930 } 931 932 /* The remaining attributes. */ 933 static PDCS_ATTR(size, 0444, pdcs_size_read, NULL); 934 static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write); 935 static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write); 936 static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL); 937 static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL); 938 static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write); 939 static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL); 940 static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL); 941 static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write); 942 943 static struct attribute *pdcs_subsys_attrs[] = { 944 &pdcs_attr_size.attr, 945 &pdcs_attr_autoboot.attr, 946 &pdcs_attr_autosearch.attr, 947 &pdcs_attr_timer.attr, 948 &pdcs_attr_osid.attr, 949 &pdcs_attr_osdep1.attr, 950 &pdcs_attr_diagnostic.attr, 951 &pdcs_attr_fastsize.attr, 952 &pdcs_attr_osdep2.attr, 953 NULL, 954 }; 955 956 static struct attribute_group pdcs_attr_group = { 957 .attrs = pdcs_subsys_attrs, 958 }; 959 960 static struct kobject *stable_kobj; 961 static struct kset *paths_kset; 962 963 /** 964 * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage. 965 * 966 * It creates kobjects corresponding to each path entry with nice sysfs 967 * links to the real device. This is where the magic takes place: when 968 * registering the subsystem attributes during module init, each kobject hereby 969 * created will show in the sysfs tree as a folder containing files as defined 970 * by path_subsys_attr[]. 971 */ 972 static inline int __init 973 pdcs_register_pathentries(void) 974 { 975 unsigned short i; 976 struct pdcspath_entry *entry; 977 int err; 978 979 /* Initialize the entries rw_lock before anything else */ 980 for (i = 0; (entry = pdcspath_entries[i]); i++) 981 rwlock_init(&entry->rw_lock); 982 983 for (i = 0; (entry = pdcspath_entries[i]); i++) { 984 write_lock(&entry->rw_lock); 985 err = pdcspath_fetch(entry); 986 write_unlock(&entry->rw_lock); 987 988 if (err < 0) 989 continue; 990 991 entry->kobj.kset = paths_kset; 992 err = kobject_init_and_add(&entry->kobj, &ktype_pdcspath, NULL, 993 "%s", entry->name); 994 if (err) 995 return err; 996 997 /* kobject is now registered */ 998 write_lock(&entry->rw_lock); 999 entry->ready = 2; 1000 1001 /* Add a nice symlink to the real device */ 1002 if (entry->dev) { 1003 err = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); 1004 WARN_ON(err); 1005 } 1006 1007 write_unlock(&entry->rw_lock); 1008 kobject_uevent(&entry->kobj, KOBJ_ADD); 1009 } 1010 1011 return 0; 1012 } 1013 1014 /** 1015 * pdcs_unregister_pathentries - Routine called when unregistering the module. 1016 */ 1017 static inline void 1018 pdcs_unregister_pathentries(void) 1019 { 1020 unsigned short i; 1021 struct pdcspath_entry *entry; 1022 1023 for (i = 0; (entry = pdcspath_entries[i]); i++) { 1024 read_lock(&entry->rw_lock); 1025 if (entry->ready >= 2) 1026 kobject_put(&entry->kobj); 1027 read_unlock(&entry->rw_lock); 1028 } 1029 } 1030 1031 /* 1032 * For now we register the stable subsystem with the firmware subsystem 1033 * and the paths subsystem with the stable subsystem 1034 */ 1035 static int __init 1036 pdc_stable_init(void) 1037 { 1038 int rc = 0, error = 0; 1039 u32 result; 1040 1041 /* find the size of the stable storage */ 1042 if (pdc_stable_get_size(&pdcs_size) != PDC_OK) 1043 return -ENODEV; 1044 1045 /* make sure we have enough data */ 1046 if (pdcs_size < 96) 1047 return -ENODATA; 1048 1049 printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION); 1050 1051 /* get OSID */ 1052 if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK) 1053 return -EIO; 1054 1055 /* the actual result is 16 bits away */ 1056 pdcs_osid = (u16)(result >> 16); 1057 1058 /* For now we'll register the directory at /sys/firmware/stable */ 1059 stable_kobj = kobject_create_and_add("stable", firmware_kobj); 1060 if (!stable_kobj) { 1061 rc = -ENOMEM; 1062 goto fail_firmreg; 1063 } 1064 1065 /* Don't forget the root entries */ 1066 error = sysfs_create_group(stable_kobj, &pdcs_attr_group); 1067 1068 /* register the paths kset as a child of the stable kset */ 1069 paths_kset = kset_create_and_add("paths", NULL, stable_kobj); 1070 if (!paths_kset) { 1071 rc = -ENOMEM; 1072 goto fail_ksetreg; 1073 } 1074 1075 /* now we create all "files" for the paths kset */ 1076 if ((rc = pdcs_register_pathentries())) 1077 goto fail_pdcsreg; 1078 1079 return rc; 1080 1081 fail_pdcsreg: 1082 pdcs_unregister_pathentries(); 1083 kset_unregister(paths_kset); 1084 1085 fail_ksetreg: 1086 kobject_put(stable_kobj); 1087 1088 fail_firmreg: 1089 printk(KERN_INFO PDCS_PREFIX " bailing out\n"); 1090 return rc; 1091 } 1092 1093 static void __exit 1094 pdc_stable_exit(void) 1095 { 1096 pdcs_unregister_pathentries(); 1097 kset_unregister(paths_kset); 1098 kobject_put(stable_kobj); 1099 } 1100 1101 1102 module_init(pdc_stable_init); 1103 module_exit(pdc_stable_exit); 1104