drivers/parisc/pdc

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

DEFINITIONS
