drivers/s390/cio/device_ops.c

   1 /*
   2  * Copyright IBM Corp. 2002, 2009
   3  *
   4  * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   5  *            Cornelia Huck (cornelia.huck@de.ibm.com)
   6  */
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/errno.h>
  10 #include <linux/slab.h>
  11 #include <linux/list.h>
  12 #include <linux/device.h>
  13 #include <linux/delay.h>
  14 #include <linux/completion.h>
  15
  16 #include <asm/ccwdev.h>
  17 #include <asm/idals.h>
  18 #include <asm/chpid.h>
  19 #include <asm/fcx.h>
  20
  21 #include "cio.h"
  22 #include "cio_debug.h"
  23 #include "css.h"
  24 #include "chsc.h"
  25 #include "device.h"
  26 #include "chp.h"
  27
  28 /**
  29  * ccw_device_set_options_mask() - set some options and unset the rest
  30  * @cdev: device for which the options are to be set
  31  * @flags: options to be set
  32  *
  33  * All flags specified in @flags are set, all flags not specified in @flags
  34  * are cleared.
  35  * Returns:
  36  *   %0 on success, -%EINVAL on an invalid flag combination.
  37  */
  38 int ccw_device_set_options_mask(struct ccw_device *cdev, unsigned long flags)
  39 {
  40        /*
  41         * The flag usage is mutal exclusive ...
  42         */
  43         if ((flags & CCWDEV_EARLY_NOTIFICATION) &&
  44             (flags & CCWDEV_REPORT_ALL))
  45                 return -EINVAL;
  46         cdev->private->options.fast = (flags & CCWDEV_EARLY_NOTIFICATION) != 0;
  47         cdev->private->options.repall = (flags & CCWDEV_REPORT_ALL) != 0;
  48         cdev->private->options.pgroup = (flags & CCWDEV_DO_PATHGROUP) != 0;
  49         cdev->private->options.force = (flags & CCWDEV_ALLOW_FORCE) != 0;
  50         cdev->private->options.mpath = (flags & CCWDEV_DO_MULTIPATH) != 0;
  51         return 0;
  52 }
  53
  54 /**
  55  * ccw_device_set_options() - set some options
  56  * @cdev: device for which the options are to be set
  57  * @flags: options to be set
  58  *
  59  * All flags specified in @flags are set, the remainder is left untouched.
  60  * Returns:
  61  *   %0 on success, -%EINVAL if an invalid flag combination would ensue.
  62  */
  63 int ccw_device_set_options(struct ccw_device *cdev, unsigned long flags)
  64 {
  65        /*
  66         * The flag usage is mutal exclusive ...
  67         */
  68         if (((flags & CCWDEV_EARLY_NOTIFICATION) &&
  69             (flags & CCWDEV_REPORT_ALL)) ||
  70             ((flags & CCWDEV_EARLY_NOTIFICATION) &&
  71              cdev->private->options.repall) ||
  72             ((flags & CCWDEV_REPORT_ALL) &&
  73              cdev->private->options.fast))
  74                 return -EINVAL;
  75         cdev->private->options.fast |= (flags & CCWDEV_EARLY_NOTIFICATION) != 0;
  76         cdev->private->options.repall |= (flags & CCWDEV_REPORT_ALL) != 0;
  77         cdev->private->options.pgroup |= (flags & CCWDEV_DO_PATHGROUP) != 0;
  78         cdev->private->options.force |= (flags & CCWDEV_ALLOW_FORCE) != 0;
  79         cdev->private->options.mpath |= (flags & CCWDEV_DO_MULTIPATH) != 0;
  80         return 0;
  81 }
  82
  83 /**
  84  * ccw_device_clear_options() - clear some options
  85  * @cdev: device for which the options are to be cleared
  86  * @flags: options to be cleared
  87  *
  88  * All flags specified in @flags are cleared, the remainder is left untouched.
  89  */
  90 void ccw_device_clear_options(struct ccw_device *cdev, unsigned long flags)
  91 {
  92         cdev->private->options.fast &= (flags & CCWDEV_EARLY_NOTIFICATION) == 0;
  93         cdev->private->options.repall &= (flags & CCWDEV_REPORT_ALL) == 0;
  94         cdev->private->options.pgroup &= (flags & CCWDEV_DO_PATHGROUP) == 0;
  95         cdev->private->options.force &= (flags & CCWDEV_ALLOW_FORCE) == 0;
  96         cdev->private->options.mpath &= (flags & CCWDEV_DO_MULTIPATH) == 0;
  97 }
  98
  99 /**
 100  * ccw_device_is_pathgroup - determine if paths to this device are grouped
 101  * @cdev: ccw device
 102  *
 103  * Return non-zero if there is a path group, zero otherwise.
 104  */
 105 int ccw_device_is_pathgroup(struct ccw_device *cdev)
 106 {
 107         return cdev->private->flags.pgroup;
 108 }
 109 EXPORT_SYMBOL(ccw_device_is_pathgroup);
 110
 111 /**
 112  * ccw_device_is_multipath - determine if device is operating in multipath mode
 113  * @cdev: ccw device
 114  *
 115  * Return non-zero if device is operating in multipath mode, zero otherwise.
 116  */
 117 int ccw_device_is_multipath(struct ccw_device *cdev)
 118 {
 119         return cdev->private->flags.mpath;
 120 }
 121 EXPORT_SYMBOL(ccw_device_is_multipath);
 122
 123 /**
 124  * ccw_device_clear() - terminate I/O request processing
 125  * @cdev: target ccw device
 126  * @intparm: interruption parameter; value is only used if no I/O is
 127  *           outstanding, otherwise the intparm associated with the I/O request
 128  *           is returned
 129  *
 130  * ccw_device_clear() calls csch on @cdev's subchannel.
 131  * Returns:
 132  *  %0 on success,
 133  *  -%ENODEV on device not operational,
 134  *  -%EINVAL on invalid device state.
 135  * Context:
 136  *  Interrupts disabled, ccw device lock held
 137  */
 138 int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
 139 {
 140         struct subchannel *sch;
 141         int ret;
 142
 143         if (!cdev || !cdev->dev.parent)
 144                 return -ENODEV;
 145         sch = to_subchannel(cdev->dev.parent);
 146         if (!sch->schib.pmcw.ena)
 147                 return -EINVAL;
 148         if (cdev->private->state == DEV_STATE_NOT_OPER)
 149                 return -ENODEV;
 150         if (cdev->private->state != DEV_STATE_ONLINE &&
 151             cdev->private->state != DEV_STATE_W4SENSE)
 152                 return -EINVAL;
 153
 154         ret = cio_clear(sch);
 155         if (ret == 0)
 156                 cdev->private->intparm = intparm;
 157         return ret;
 158 }
 159
 160 /**
 161  * ccw_device_start_key() - start a s390 channel program with key
 162  * @cdev: target ccw device
 163  * @cpa: logical start address of channel program
 164  * @intparm: user specific interruption parameter; will be presented back to
 165  *           @cdev's interrupt handler. Allows a device driver to associate
 166  *           the interrupt with a particular I/O request.
 167  * @lpm: defines the channel path to be used for a specific I/O request. A
 168  *       value of 0 will make cio use the opm.
 169  * @key: storage key to be used for the I/O
 170  * @flags: additional flags; defines the action to be performed for I/O
 171  *         processing.
 172  *
 173  * Start a S/390 channel program. When the interrupt arrives, the
 174  * IRQ handler is called, either immediately, delayed (dev-end missing,
 175  * or sense required) or never (no IRQ handler registered).
 176  * Returns:
 177  *  %0, if the operation was successful;
 178  *  -%EBUSY, if the device is busy, or status pending;
 179  *  -%EACCES, if no path specified in @lpm is operational;
 180  *  -%ENODEV, if the device is not operational.
 181  * Context:
 182  *  Interrupts disabled, ccw device lock held
 183  */
 184 int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
 185                          unsigned long intparm, __u8 lpm, __u8 key,
 186                          unsigned long flags)
 187 {
 188         struct subchannel *sch;
 189         int ret;
 190
 191         if (!cdev || !cdev->dev.parent)
 192                 return -ENODEV;
 193         sch = to_subchannel(cdev->dev.parent);
 194         if (!sch->schib.pmcw.ena)
 195                 return -EINVAL;
 196         if (cdev->private->state == DEV_STATE_NOT_OPER)
 197                 return -ENODEV;
 198         if (cdev->private->state == DEV_STATE_VERIFY) {
 199                 /* Remember to fake irb when finished. */
 200                 if (!cdev->private->flags.fake_irb) {
 201                         cdev->private->flags.fake_irb = FAKE_CMD_IRB;
 202                         cdev->private->intparm = intparm;
 203                         return 0;
 204                 } else
 205                         /* There's already a fake I/O around. */
 206                         return -EBUSY;
 207         }
 208         if (cdev->private->state != DEV_STATE_ONLINE ||
 209             ((sch->schib.scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) &&
 210              !(sch->schib.scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS)) ||
 211             cdev->private->flags.doverify)
 212                 return -EBUSY;
 213         ret = cio_set_options (sch, flags);
 214         if (ret)
 215                 return ret;
 216         /* Adjust requested path mask to exclude unusable paths. */
 217         if (lpm) {
 218                 lpm &= sch->lpm;
 219                 if (lpm == 0)
 220                         return -EACCES;
 221         }
 222         ret = cio_start_key (sch, cpa, lpm, key);
 223         switch (ret) {
 224         case 0:
 225                 cdev->private->intparm = intparm;
 226                 break;
 227         case -EACCES:
 228         case -ENODEV:
 229                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 230                 break;
 231         }
 232         return ret;
 233 }
 234
 235 /**
 236  * ccw_device_start_timeout_key() - start a s390 channel program with timeout and key
 237  * @cdev: target ccw device
 238  * @cpa: logical start address of channel program
 239  * @intparm: user specific interruption parameter; will be presented back to
 240  *           @cdev's interrupt handler. Allows a device driver to associate
 241  *           the interrupt with a particular I/O request.
 242  * @lpm: defines the channel path to be used for a specific I/O request. A
 243  *       value of 0 will make cio use the opm.
 244  * @key: storage key to be used for the I/O
 245  * @flags: additional flags; defines the action to be performed for I/O
 246  *         processing.
 247  * @expires: timeout value in jiffies
 248  *
 249  * Start a S/390 channel program. When the interrupt arrives, the
 250  * IRQ handler is called, either immediately, delayed (dev-end missing,
 251  * or sense required) or never (no IRQ handler registered).
 252  * This function notifies the device driver if the channel program has not
 253  * completed during the time specified by @expires. If a timeout occurs, the
 254  * channel program is terminated via xsch, hsch or csch, and the device's
 255  * interrupt handler will be called with an irb containing ERR_PTR(-%ETIMEDOUT).
 256  * Returns:
 257  *  %0, if the operation was successful;
 258  *  -%EBUSY, if the device is busy, or status pending;
 259  *  -%EACCES, if no path specified in @lpm is operational;
 260  *  -%ENODEV, if the device is not operational.
 261  * Context:
 262  *  Interrupts disabled, ccw device lock held
 263  */
 264 int ccw_device_start_timeout_key(struct ccw_device *cdev, struct ccw1 *cpa,
 265                                  unsigned long intparm, __u8 lpm, __u8 key,
 266                                  unsigned long flags, int expires)
 267 {
 268         int ret;
 269
 270         if (!cdev)
 271                 return -ENODEV;
 272         ccw_device_set_timeout(cdev, expires);
 273         ret = ccw_device_start_key(cdev, cpa, intparm, lpm, key, flags);
 274         if (ret != 0)
 275                 ccw_device_set_timeout(cdev, 0);
 276         return ret;
 277 }
 278
 279 /**
 280  * ccw_device_start() - start a s390 channel program
 281  * @cdev: target ccw device
 282  * @cpa: logical start address of channel program
 283  * @intparm: user specific interruption parameter; will be presented back to
 284  *           @cdev's interrupt handler. Allows a device driver to associate
 285  *           the interrupt with a particular I/O request.
 286  * @lpm: defines the channel path to be used for a specific I/O request. A
 287  *       value of 0 will make cio use the opm.
 288  * @flags: additional flags; defines the action to be performed for I/O
 289  *         processing.
 290  *
 291  * Start a S/390 channel program. When the interrupt arrives, the
 292  * IRQ handler is called, either immediately, delayed (dev-end missing,
 293  * or sense required) or never (no IRQ handler registered).
 294  * Returns:
 295  *  %0, if the operation was successful;
 296  *  -%EBUSY, if the device is busy, or status pending;
 297  *  -%EACCES, if no path specified in @lpm is operational;
 298  *  -%ENODEV, if the device is not operational.
 299  * Context:
 300  *  Interrupts disabled, ccw device lock held
 301  */
 302 int ccw_device_start(struct ccw_device *cdev, struct ccw1 *cpa,
 303                      unsigned long intparm, __u8 lpm, unsigned long flags)
 304 {
 305         return ccw_device_start_key(cdev, cpa, intparm, lpm,
 306                                     PAGE_DEFAULT_KEY, flags);
 307 }
 308
 309 /**
 310  * ccw_device_start_timeout() - start a s390 channel program with timeout
 311  * @cdev: target ccw device
 312  * @cpa: logical start address of channel program
 313  * @intparm: user specific interruption parameter; will be presented back to
 314  *           @cdev's interrupt handler. Allows a device driver to associate
 315  *           the interrupt with a particular I/O request.
 316  * @lpm: defines the channel path to be used for a specific I/O request. A
 317  *       value of 0 will make cio use the opm.
 318  * @flags: additional flags; defines the action to be performed for I/O
 319  *         processing.
 320  * @expires: timeout value in jiffies
 321  *
 322  * Start a S/390 channel program. When the interrupt arrives, the
 323  * IRQ handler is called, either immediately, delayed (dev-end missing,
 324  * or sense required) or never (no IRQ handler registered).
 325  * This function notifies the device driver if the channel program has not
 326  * completed during the time specified by @expires. If a timeout occurs, the
 327  * channel program is terminated via xsch, hsch or csch, and the device's
 328  * interrupt handler will be called with an irb containing ERR_PTR(-%ETIMEDOUT).
 329  * Returns:
 330  *  %0, if the operation was successful;
 331  *  -%EBUSY, if the device is busy, or status pending;
 332  *  -%EACCES, if no path specified in @lpm is operational;
 333  *  -%ENODEV, if the device is not operational.
 334  * Context:
 335  *  Interrupts disabled, ccw device lock held
 336  */
 337 int ccw_device_start_timeout(struct ccw_device *cdev, struct ccw1 *cpa,
 338                              unsigned long intparm, __u8 lpm,
 339                              unsigned long flags, int expires)
 340 {
 341         return ccw_device_start_timeout_key(cdev, cpa, intparm, lpm,
 342                                             PAGE_DEFAULT_KEY, flags,
 343                                             expires);
 344 }
 345
 346
 347 /**
 348  * ccw_device_halt() - halt I/O request processing
 349  * @cdev: target ccw device
 350  * @intparm: interruption parameter; value is only used if no I/O is
 351  *           outstanding, otherwise the intparm associated with the I/O request
 352  *           is returned
 353  *
 354  * ccw_device_halt() calls hsch on @cdev's subchannel.
 355  * Returns:
 356  *  %0 on success,
 357  *  -%ENODEV on device not operational,
 358  *  -%EINVAL on invalid device state,
 359  *  -%EBUSY on device busy or interrupt pending.
 360  * Context:
 361  *  Interrupts disabled, ccw device lock held
 362  */
 363 int ccw_device_halt(struct ccw_device *cdev, unsigned long intparm)
 364 {
 365         struct subchannel *sch;
 366         int ret;
 367
 368         if (!cdev || !cdev->dev.parent)
 369                 return -ENODEV;
 370         sch = to_subchannel(cdev->dev.parent);
 371         if (!sch->schib.pmcw.ena)
 372                 return -EINVAL;
 373         if (cdev->private->state == DEV_STATE_NOT_OPER)
 374                 return -ENODEV;
 375         if (cdev->private->state != DEV_STATE_ONLINE &&
 376             cdev->private->state != DEV_STATE_W4SENSE)
 377                 return -EINVAL;
 378
 379         ret = cio_halt(sch);
 380         if (ret == 0)
 381                 cdev->private->intparm = intparm;
 382         return ret;
 383 }
 384
 385 /**
 386  * ccw_device_resume() - resume channel program execution
 387  * @cdev: target ccw device
 388  *
 389  * ccw_device_resume() calls rsch on @cdev's subchannel.
 390  * Returns:
 391  *  %0 on success,
 392  *  -%ENODEV on device not operational,
 393  *  -%EINVAL on invalid device state,
 394  *  -%EBUSY on device busy or interrupt pending.
 395  * Context:
 396  *  Interrupts disabled, ccw device lock held
 397  */
 398 int ccw_device_resume(struct ccw_device *cdev)
 399 {
 400         struct subchannel *sch;
 401
 402         if (!cdev || !cdev->dev.parent)
 403                 return -ENODEV;
 404         sch = to_subchannel(cdev->dev.parent);
 405         if (!sch->schib.pmcw.ena)
 406                 return -EINVAL;
 407         if (cdev->private->state == DEV_STATE_NOT_OPER)
 408                 return -ENODEV;
 409         if (cdev->private->state != DEV_STATE_ONLINE ||
 410             !(sch->schib.scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
 411                 return -EINVAL;
 412         return cio_resume(sch);
 413 }
 414
 415 /**
 416  * ccw_device_get_ciw() - Search for CIW command in extended sense data.
 417  * @cdev: ccw device to inspect
 418  * @ct: command type to look for
 419  *
 420  * During SenseID, command information words (CIWs) describing special
 421  * commands available to the device may have been stored in the extended
 422  * sense data. This function searches for CIWs of a specified command
 423  * type in the extended sense data.
 424  * Returns:
 425  *  %NULL if no extended sense data has been stored or if no CIW of the
 426  *  specified command type could be found,
 427  *  else a pointer to the CIW of the specified command type.
 428  */
 429 struct ciw *ccw_device_get_ciw(struct ccw_device *cdev, __u32 ct)
 430 {
 431         int ciw_cnt;
 432
 433         if (cdev->private->flags.esid == 0)
 434                 return NULL;
 435         for (ciw_cnt = 0; ciw_cnt < MAX_CIWS; ciw_cnt++)
 436                 if (cdev->private->senseid.ciw[ciw_cnt].ct == ct)
 437                         return cdev->private->senseid.ciw + ciw_cnt;
 438         return NULL;
 439 }
 440
 441 /**
 442  * ccw_device_get_path_mask() - get currently available paths
 443  * @cdev: ccw device to be queried
 444  * Returns:
 445  *  %0 if no subchannel for the device is available,
 446  *  else the mask of currently available paths for the ccw device's subchannel.
 447  */
 448 __u8 ccw_device_get_path_mask(struct ccw_device *cdev)
 449 {
 450         struct subchannel *sch;
 451
 452         if (!cdev->dev.parent)
 453                 return 0;
 454
 455         sch = to_subchannel(cdev->dev.parent);
 456         return sch->lpm;
 457 }
 458
 459 /**
 460  * chp_get_chp_desc - return newly allocated channel-path descriptor
 461  * @cdev: device to obtain the descriptor for
 462  * @chp_idx: index of the channel path
 463  *
 464  * On success return a newly allocated copy of the channel-path description
 465  * data associated with the given channel path. Return %NULL on error.
 466  */
 467 struct channel_path_desc *ccw_device_get_chp_desc(struct ccw_device *cdev,
 468                                                   int chp_idx)
 469 {
 470         struct subchannel *sch;
 471         struct chp_id chpid;
 472
 473         sch = to_subchannel(cdev->dev.parent);
 474         chp_id_init(&chpid);
 475         chpid.id = sch->schib.pmcw.chpid[chp_idx];
 476         return chp_get_chp_desc(chpid);
 477 }
 478
 479 /**
 480  * ccw_device_get_id - obtain a ccw device id
 481  * @cdev: device to obtain the id for
 482  * @dev_id: where to fill in the values
 483  */
 484 void ccw_device_get_id(struct ccw_device *cdev, struct ccw_dev_id *dev_id)
 485 {
 486         *dev_id = cdev->private->dev_id;
 487 }
 488 EXPORT_SYMBOL(ccw_device_get_id);
 489
 490 /**
 491  * ccw_device_tm_start_key - perform start function
 492  * @cdev: ccw device on which to perform the start function
 493  * @tcw: transport-command word to be started
 494  * @intparm: user defined parameter to be passed to the interrupt handler
 495  * @lpm: mask of paths to use
 496  * @key: storage key to use for storage access
 497  *
 498  * Start the tcw on the given ccw device. Return zero on success, non-zero
 499  * otherwise.
 500  */
 501 int ccw_device_tm_start_key(struct ccw_device *cdev, struct tcw *tcw,
 502                             unsigned long intparm, u8 lpm, u8 key)
 503 {
 504         struct subchannel *sch;
 505         int rc;
 506
 507         sch = to_subchannel(cdev->dev.parent);
 508         if (!sch->schib.pmcw.ena)
 509                 return -EINVAL;
 510         if (cdev->private->state == DEV_STATE_VERIFY) {
 511                 /* Remember to fake irb when finished. */
 512                 if (!cdev->private->flags.fake_irb) {
 513                         cdev->private->flags.fake_irb = FAKE_TM_IRB;
 514                         cdev->private->intparm = intparm;
 515                         return 0;
 516                 } else
 517                         /* There's already a fake I/O around. */
 518                         return -EBUSY;
 519         }
 520         if (cdev->private->state != DEV_STATE_ONLINE)
 521                 return -EIO;
 522         /* Adjust requested path mask to exclude unusable paths. */
 523         if (lpm) {
 524                 lpm &= sch->lpm;
 525                 if (lpm == 0)
 526                         return -EACCES;
 527         }
 528         rc = cio_tm_start_key(sch, tcw, lpm, key);
 529         if (rc == 0)
 530                 cdev->private->intparm = intparm;
 531         return rc;
 532 }
 533 EXPORT_SYMBOL(ccw_device_tm_start_key);
 534
 535 /**
 536  * ccw_device_tm_start_timeout_key - perform start function
 537  * @cdev: ccw device on which to perform the start function
 538  * @tcw: transport-command word to be started
 539  * @intparm: user defined parameter to be passed to the interrupt handler
 540  * @lpm: mask of paths to use
 541  * @key: storage key to use for storage access
 542  * @expires: time span in jiffies after which to abort request
 543  *
 544  * Start the tcw on the given ccw device. Return zero on success, non-zero
 545  * otherwise.
 546  */
 547 int ccw_device_tm_start_timeout_key(struct ccw_device *cdev, struct tcw *tcw,
 548                                     unsigned long intparm, u8 lpm, u8 key,
 549                                     int expires)
 550 {
 551         int ret;
 552
 553         ccw_device_set_timeout(cdev, expires);
 554         ret = ccw_device_tm_start_key(cdev, tcw, intparm, lpm, key);
 555         if (ret != 0)
 556                 ccw_device_set_timeout(cdev, 0);
 557         return ret;
 558 }
 559 EXPORT_SYMBOL(ccw_device_tm_start_timeout_key);
 560
 561 /**
 562  * ccw_device_tm_start - perform start function
 563  * @cdev: ccw device on which to perform the start function
 564  * @tcw: transport-command word to be started
 565  * @intparm: user defined parameter to be passed to the interrupt handler
 566  * @lpm: mask of paths to use
 567  *
 568  * Start the tcw on the given ccw device. Return zero on success, non-zero
 569  * otherwise.
 570  */
 571 int ccw_device_tm_start(struct ccw_device *cdev, struct tcw *tcw,
 572                         unsigned long intparm, u8 lpm)
 573 {
 574         return ccw_device_tm_start_key(cdev, tcw, intparm, lpm,
 575                                        PAGE_DEFAULT_KEY);
 576 }
 577 EXPORT_SYMBOL(ccw_device_tm_start);
 578
 579 /**
 580  * ccw_device_tm_start_timeout - perform start function
 581  * @cdev: ccw device on which to perform the start function
 582  * @tcw: transport-command word to be started
 583  * @intparm: user defined parameter to be passed to the interrupt handler
 584  * @lpm: mask of paths to use
 585  * @expires: time span in jiffies after which to abort request
 586  *
 587  * Start the tcw on the given ccw device. Return zero on success, non-zero
 588  * otherwise.
 589  */
 590 int ccw_device_tm_start_timeout(struct ccw_device *cdev, struct tcw *tcw,
 591                                unsigned long intparm, u8 lpm, int expires)
 592 {
 593         return ccw_device_tm_start_timeout_key(cdev, tcw, intparm, lpm,
 594                                                PAGE_DEFAULT_KEY, expires);
 595 }
 596 EXPORT_SYMBOL(ccw_device_tm_start_timeout);
 597
 598 /**
 599  * ccw_device_get_mdc - accumulate max data count
 600  * @cdev: ccw device for which the max data count is accumulated
 601  * @mask: mask of paths to use
 602  *
 603  * Return the number of 64K-bytes blocks all paths at least support
 604  * for a transport command. Return values <= 0 indicate failures.
 605  */
 606 int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
 607 {
 608         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 609         struct channel_path *chp;
 610         struct chp_id chpid;
 611         int mdc = 0, i;
 612
 613         /* Adjust requested path mask to excluded varied off paths. */
 614         if (mask)
 615                 mask &= sch->lpm;
 616         else
 617                 mask = sch->lpm;
 618
 619         chp_id_init(&chpid);
 620         for (i = 0; i < 8; i++) {
 621                 if (!(mask & (0x80 >> i)))
 622                         continue;
 623                 chpid.id = sch->schib.pmcw.chpid[i];
 624                 chp = chpid_to_chp(chpid);
 625                 if (!chp)
 626                         continue;
 627
 628                 mutex_lock(&chp->lock);
 629                 if (!chp->desc_fmt1.f) {
 630                         mutex_unlock(&chp->lock);
 631                         return 0;
 632                 }
 633                 if (!chp->desc_fmt1.r)
 634                         mdc = 1;
 635                 mdc = mdc ? min_t(int, mdc, chp->desc_fmt1.mdc) :
 636                             chp->desc_fmt1.mdc;
 637                 mutex_unlock(&chp->lock);
 638         }
 639
 640         return mdc;
 641 }
 642 EXPORT_SYMBOL(ccw_device_get_mdc);
 643
 644 /**
 645  * ccw_device_tm_intrg - perform interrogate function
 646  * @cdev: ccw device on which to perform the interrogate function
 647  *
 648  * Perform an interrogate function on the given ccw device. Return zero on
 649  * success, non-zero otherwise.
 650  */
 651 int ccw_device_tm_intrg(struct ccw_device *cdev)
 652 {
 653         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 654
 655         if (!sch->schib.pmcw.ena)
 656                 return -EINVAL;
 657         if (cdev->private->state != DEV_STATE_ONLINE)
 658                 return -EIO;
 659         if (!scsw_is_tm(&sch->schib.scsw) ||
 660             !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_START_PEND))
 661                 return -EINVAL;
 662         return cio_tm_intrg(sch);
 663 }
 664 EXPORT_SYMBOL(ccw_device_tm_intrg);
 665
 666 /**
 667  * ccw_device_get_schid - obtain a subchannel id
 668  * @cdev: device to obtain the id for
 669  * @schid: where to fill in the values
 670  */
 671 void ccw_device_get_schid(struct ccw_device *cdev, struct subchannel_id *schid)
 672 {
 673         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 674
 675         *schid = sch->schid;
 676 }
 677 EXPORT_SYMBOL_GPL(ccw_device_get_schid);
 678
 679 MODULE_LICENSE("GPL");
 680 EXPORT_SYMBOL(ccw_device_set_options_mask);
 681 EXPORT_SYMBOL(ccw_device_set_options);
 682 EXPORT_SYMBOL(ccw_device_clear_options);
 683 EXPORT_SYMBOL(ccw_device_clear);
 684 EXPORT_SYMBOL(ccw_device_halt);
 685 EXPORT_SYMBOL(ccw_device_resume);
 686 EXPORT_SYMBOL(ccw_device_start_timeout);
 687 EXPORT_SYMBOL(ccw_device_start);
 688 EXPORT_SYMBOL(ccw_device_start_timeout_key);
 689 EXPORT_SYMBOL(ccw_device_start_key);
 690 EXPORT_SYMBOL(ccw_device_get_ciw);
 691 EXPORT_SYMBOL(ccw_device_get_path_mask);
 692 EXPORT_SYMBOL_GPL(ccw_device_get_chp_desc);