drivers/s390/cio/cmf.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Linux on zSeries Channel Measurement Facility support
   4  *
   5  * Copyright IBM Corp. 2000, 2006
   6  *
   7  * Authors: Arnd Bergmann <arndb@de.ibm.com>
   8  *          Cornelia Huck <cornelia.huck@de.ibm.com>
   9  *
  10  * original idea from Natarajan Krishnaswami <nkrishna@us.ibm.com>
  11  */
  12
  13 #define KMSG_COMPONENT "cio"
  14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  15
  16 #include <linux/memblock.h>
  17 #include <linux/device.h>
  18 #include <linux/init.h>
  19 #include <linux/list.h>
  20 #include <linux/export.h>
  21 #include <linux/moduleparam.h>
  22 #include <linux/slab.h>
  23 #include <linux/timex.h>        /* get_tod_clock() */
  24
  25 #include <asm/ccwdev.h>
  26 #include <asm/cio.h>
  27 #include <asm/cmb.h>
  28 #include <asm/div64.h>
  29
  30 #include "cio.h"
  31 #include "css.h"
  32 #include "device.h"
  33 #include "ioasm.h"
  34 #include "chsc.h"
  35
  36 /*
  37  * parameter to enable cmf during boot, possible uses are:
  38  *  "s390cmf" -- enable cmf and allocate 2 MB of ram so measuring can be
  39  *               used on any subchannel
  40  *  "s390cmf=<num>" -- enable cmf and allocate enough memory to measure
  41  *                     <num> subchannel, where <num> is an integer
  42  *                     between 1 and 65535, default is 1024
  43  */
  44 #define ARGSTRING "s390cmf"
  45
  46 /* indices for READCMB */
  47 enum cmb_index {
  48         avg_utilization = -1,
  49  /* basic and exended format: */
  50         cmb_ssch_rsch_count = 0,
  51         cmb_sample_count,
  52         cmb_device_connect_time,
  53         cmb_function_pending_time,
  54         cmb_device_disconnect_time,
  55         cmb_control_unit_queuing_time,
  56         cmb_device_active_only_time,
  57  /* extended format only: */
  58         cmb_device_busy_time,
  59         cmb_initial_command_response_time,
  60 };
  61
  62 /**
  63  * enum cmb_format - types of supported measurement block formats
  64  *
  65  * @CMF_BASIC:      traditional channel measurement blocks supported
  66  *                  by all machines that we run on
  67  * @CMF_EXTENDED:   improved format that was introduced with the z990
  68  *                  machine
  69  * @CMF_AUTODETECT: default: use extended format when running on a machine
  70  *                  supporting extended format, otherwise fall back to
  71  *                  basic format
  72  */
  73 enum cmb_format {
  74         CMF_BASIC,
  75         CMF_EXTENDED,
  76         CMF_AUTODETECT = -1,
  77 };
  78
  79 /*
  80  * format - actual format for all measurement blocks
  81  *
  82  * The format module parameter can be set to a value of 0 (zero)
  83  * or 1, indicating basic or extended format as described for
  84  * enum cmb_format.
  85  */
  86 static int format = CMF_AUTODETECT;
  87 module_param(format, bint, 0444);
  88
  89 /**
  90  * struct cmb_operations - functions to use depending on cmb_format
  91  *
  92  * Most of these functions operate on a struct ccw_device. There is only
  93  * one instance of struct cmb_operations because the format of the measurement
  94  * data is guaranteed to be the same for every ccw_device.
  95  *
  96  * @alloc:      allocate memory for a channel measurement block,
  97  *              either with the help of a special pool or with kmalloc
  98  * @free:       free memory allocated with @alloc
  99  * @set:        enable or disable measurement
 100  * @read:       read a measurement entry at an index
 101  * @readall:    read a measurement block in a common format
 102  * @reset:      clear the data in the associated measurement block and
 103  *              reset its time stamp
 104  */
 105 struct cmb_operations {
 106         int  (*alloc)  (struct ccw_device *);
 107         void (*free)   (struct ccw_device *);
 108         int  (*set)    (struct ccw_device *, u32);
 109         u64  (*read)   (struct ccw_device *, int);
 110         int  (*readall)(struct ccw_device *, struct cmbdata *);
 111         void (*reset)  (struct ccw_device *);
 112 /* private: */
 113         struct attribute_group *attr_group;
 114 };
 115 static struct cmb_operations *cmbops;
 116
 117 struct cmb_data {
 118         void *hw_block;   /* Pointer to block updated by hardware */
 119         void *last_block; /* Last changed block copied from hardware block */
 120         int size;         /* Size of hw_block and last_block */
 121         unsigned long long last_update;  /* when last_block was updated */
 122 };
 123
 124 /*
 125  * Our user interface is designed in terms of nanoseconds,
 126  * while the hardware measures total times in its own
 127  * unit.
 128  */
 129 static inline u64 time_to_nsec(u32 value)
 130 {
 131         return ((u64)value) * 128000ull;
 132 }
 133
 134 /*
 135  * Users are usually interested in average times,
 136  * not accumulated time.
 137  * This also helps us with atomicity problems
 138  * when reading sinlge values.
 139  */
 140 static inline u64 time_to_avg_nsec(u32 value, u32 count)
 141 {
 142         u64 ret;
 143
 144         /* no samples yet, avoid division by 0 */
 145         if (count == 0)
 146                 return 0;
 147
 148         /* value comes in units of 128 µsec */
 149         ret = time_to_nsec(value);
 150         do_div(ret, count);
 151
 152         return ret;
 153 }
 154
 155 #define CMF_OFF 0
 156 #define CMF_ON  2
 157
 158 /*
 159  * Activate or deactivate the channel monitor. When area is NULL,
 160  * the monitor is deactivated. The channel monitor needs to
 161  * be active in order to measure subchannels, which also need
 162  * to be enabled.
 163  */
 164 static inline void cmf_activate(void *area, unsigned int onoff)
 165 {
 166         /* activate channel measurement */
 167         asm volatile(
 168                 "       lgr     1,%[r1]\n"
 169                 "       lgr     2,%[mbo]\n"
 170                 "       schm\n"
 171                 :
 172                 : [r1] "d" ((unsigned long)onoff), [mbo] "d" (area)
 173                 : "1", "2");
 174 }
 175
 176 static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
 177                      unsigned long address)
 178 {
 179         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 180         int ret;
 181
 182         sch->config.mme = mme;
 183         sch->config.mbfc = mbfc;
 184         /* address can be either a block address or a block index */
 185         if (mbfc)
 186                 sch->config.mba = address;
 187         else
 188                 sch->config.mbi = address;
 189
 190         ret = cio_commit_config(sch);
 191         if (!mme && ret == -ENODEV) {
 192                 /*
 193                  * The task was to disable measurement block updates but
 194                  * the subchannel is already gone. Report success.
 195                  */
 196                 ret = 0;
 197         }
 198         return ret;
 199 }
 200
 201 struct set_schib_struct {
 202         u32 mme;
 203         int mbfc;
 204         unsigned long address;
 205         wait_queue_head_t wait;
 206         int ret;
 207 };
 208
 209 #define CMF_PENDING 1
 210 #define SET_SCHIB_TIMEOUT (10 * HZ)
 211
 212 static int set_schib_wait(struct ccw_device *cdev, u32 mme,
 213                           int mbfc, unsigned long address)
 214 {
 215         struct set_schib_struct set_data;
 216         int ret = -ENODEV;
 217
 218         spin_lock_irq(cdev->ccwlock);
 219         if (!cdev->private->cmb)
 220                 goto out;
 221
 222         ret = set_schib(cdev, mme, mbfc, address);
 223         if (ret != -EBUSY)
 224                 goto out;
 225
 226         /* if the device is not online, don't even try again */
 227         if (cdev->private->state != DEV_STATE_ONLINE)
 228                 goto out;
 229
 230         init_waitqueue_head(&set_data.wait);
 231         set_data.mme = mme;
 232         set_data.mbfc = mbfc;
 233         set_data.address = address;
 234         set_data.ret = CMF_PENDING;
 235
 236         cdev->private->state = DEV_STATE_CMFCHANGE;
 237         cdev->private->cmb_wait = &set_data;
 238         spin_unlock_irq(cdev->ccwlock);
 239
 240         ret = wait_event_interruptible_timeout(set_data.wait,
 241                                                set_data.ret != CMF_PENDING,
 242                                                SET_SCHIB_TIMEOUT);
 243         spin_lock_irq(cdev->ccwlock);
 244         if (ret <= 0) {
 245                 if (set_data.ret == CMF_PENDING) {
 246                         set_data.ret = (ret == 0) ? -ETIME : ret;
 247                         if (cdev->private->state == DEV_STATE_CMFCHANGE)
 248                                 cdev->private->state = DEV_STATE_ONLINE;
 249                 }
 250         }
 251         cdev->private->cmb_wait = NULL;
 252         ret = set_data.ret;
 253 out:
 254         spin_unlock_irq(cdev->ccwlock);
 255         return ret;
 256 }
 257
 258 void retry_set_schib(struct ccw_device *cdev)
 259 {
 260         struct set_schib_struct *set_data = cdev->private->cmb_wait;
 261
 262         if (!set_data)
 263                 return;
 264
 265         set_data->ret = set_schib(cdev, set_data->mme, set_data->mbfc,
 266                                   set_data->address);
 267         wake_up(&set_data->wait);
 268 }
 269
 270 static int cmf_copy_block(struct ccw_device *cdev)
 271 {
 272         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 273         struct cmb_data *cmb_data;
 274         void *hw_block;
 275
 276         if (cio_update_schib(sch))
 277                 return -ENODEV;
 278
 279         if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
 280                 /* Don't copy if a start function is in progress. */
 281                 if ((!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_SUSPENDED)) &&
 282                     (scsw_actl(&sch->schib.scsw) &
 283                      (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) &&
 284                     (!(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_SEC_STATUS)))
 285                         return -EBUSY;
 286         }
 287         cmb_data = cdev->private->cmb;
 288         hw_block = cmb_data->hw_block;
 289         memcpy(cmb_data->last_block, hw_block, cmb_data->size);
 290         cmb_data->last_update = get_tod_clock();
 291         return 0;
 292 }
 293
 294 struct copy_block_struct {
 295         wait_queue_head_t wait;
 296         int ret;
 297 };
 298
 299 static int cmf_cmb_copy_wait(struct ccw_device *cdev)
 300 {
 301         struct copy_block_struct copy_block;
 302         int ret = -ENODEV;
 303
 304         spin_lock_irq(cdev->ccwlock);
 305         if (!cdev->private->cmb)
 306                 goto out;
 307
 308         ret = cmf_copy_block(cdev);
 309         if (ret != -EBUSY)
 310                 goto out;
 311
 312         if (cdev->private->state != DEV_STATE_ONLINE)
 313                 goto out;
 314
 315         init_waitqueue_head(&copy_block.wait);
 316         copy_block.ret = CMF_PENDING;
 317
 318         cdev->private->state = DEV_STATE_CMFUPDATE;
 319         cdev->private->cmb_wait = &copy_block;
 320         spin_unlock_irq(cdev->ccwlock);
 321
 322         ret = wait_event_interruptible(copy_block.wait,
 323                                        copy_block.ret != CMF_PENDING);
 324         spin_lock_irq(cdev->ccwlock);
 325         if (ret) {
 326                 if (copy_block.ret == CMF_PENDING) {
 327                         copy_block.ret = -ERESTARTSYS;
 328                         if (cdev->private->state == DEV_STATE_CMFUPDATE)
 329                                 cdev->private->state = DEV_STATE_ONLINE;
 330                 }
 331         }
 332         cdev->private->cmb_wait = NULL;
 333         ret = copy_block.ret;
 334 out:
 335         spin_unlock_irq(cdev->ccwlock);
 336         return ret;
 337 }
 338
 339 void cmf_retry_copy_block(struct ccw_device *cdev)
 340 {
 341         struct copy_block_struct *copy_block = cdev->private->cmb_wait;
 342
 343         if (!copy_block)
 344                 return;
 345
 346         copy_block->ret = cmf_copy_block(cdev);
 347         wake_up(&copy_block->wait);
 348 }
 349
 350 static void cmf_generic_reset(struct ccw_device *cdev)
 351 {
 352         struct cmb_data *cmb_data;
 353
 354         spin_lock_irq(cdev->ccwlock);
 355         cmb_data = cdev->private->cmb;
 356         if (cmb_data) {
 357                 memset(cmb_data->last_block, 0, cmb_data->size);
 358                 /*
 359                  * Need to reset hw block as well to make the hardware start
 360                  * from 0 again.
 361                  */
 362                 memset(cmb_data->hw_block, 0, cmb_data->size);
 363                 cmb_data->last_update = 0;
 364         }
 365         cdev->private->cmb_start_time = get_tod_clock();
 366         spin_unlock_irq(cdev->ccwlock);
 367 }
 368
 369 /**
 370  * struct cmb_area - container for global cmb data
 371  *
 372  * @mem:        pointer to CMBs (only in basic measurement mode)
 373  * @list:       contains a linked list of all subchannels
 374  * @num_channels: number of channels to be measured
 375  * @lock:       protect concurrent access to @mem and @list
 376  */
 377 struct cmb_area {
 378         struct cmb *mem;
 379         struct list_head list;
 380         int num_channels;
 381         spinlock_t lock;
 382 };
 383
 384 static struct cmb_area cmb_area = {
 385         .lock = __SPIN_LOCK_UNLOCKED(cmb_area.lock),
 386         .list = LIST_HEAD_INIT(cmb_area.list),
 387         .num_channels  = 1024,
 388 };
 389
 390 /* ****** old style CMB handling ********/
 391
 392 /*
 393  * Basic channel measurement blocks are allocated in one contiguous
 394  * block of memory, which can not be moved as long as any channel
 395  * is active. Therefore, a maximum number of subchannels needs to
 396  * be defined somewhere. This is a module parameter, defaulting to
 397  * a reasonable value of 1024, or 32 kb of memory.
 398  * Current kernels don't allow kmalloc with more than 128kb, so the
 399  * maximum is 4096.
 400  */
 401
 402 module_param_named(maxchannels, cmb_area.num_channels, uint, 0444);
 403
 404 /**
 405  * struct cmb - basic channel measurement block
 406  * @ssch_rsch_count: number of ssch and rsch
 407  * @sample_count: number of samples
 408  * @device_connect_time: time of device connect
 409  * @function_pending_time: time of function pending
 410  * @device_disconnect_time: time of device disconnect
 411  * @control_unit_queuing_time: time of control unit queuing
 412  * @device_active_only_time: time of device active only
 413  * @reserved: unused in basic measurement mode
 414  *
 415  * The measurement block as used by the hardware. The fields are described
 416  * further in z/Architecture Principles of Operation, chapter 17.
 417  *
 418  * The cmb area made up from these blocks must be a contiguous array and may
 419  * not be reallocated or freed.
 420  * Only one cmb area can be present in the system.
 421  */
 422 struct cmb {
 423         u16 ssch_rsch_count;
 424         u16 sample_count;
 425         u32 device_connect_time;
 426         u32 function_pending_time;
 427         u32 device_disconnect_time;
 428         u32 control_unit_queuing_time;
 429         u32 device_active_only_time;
 430         u32 reserved[2];
 431 };
 432
 433 /*
 434  * Insert a single device into the cmb_area list.
 435  * Called with cmb_area.lock held from alloc_cmb.
 436  */
 437 static int alloc_cmb_single(struct ccw_device *cdev,
 438                             struct cmb_data *cmb_data)
 439 {
 440         struct cmb *cmb;
 441         struct ccw_device_private *node;
 442         int ret;
 443
 444         spin_lock_irq(cdev->ccwlock);
 445         if (!list_empty(&cdev->private->cmb_list)) {
 446                 ret = -EBUSY;
 447                 goto out;
 448         }
 449
 450         /*
 451          * Find first unused cmb in cmb_area.mem.
 452          * This is a little tricky: cmb_area.list
 453          * remains sorted by ->cmb->hw_data pointers.
 454          */
 455         cmb = cmb_area.mem;
 456         list_for_each_entry(node, &cmb_area.list, cmb_list) {
 457                 struct cmb_data *data;
 458                 data = node->cmb;
 459                 if ((struct cmb*)data->hw_block > cmb)
 460                         break;
 461                 cmb++;
 462         }
 463         if (cmb - cmb_area.mem >= cmb_area.num_channels) {
 464                 ret = -ENOMEM;
 465                 goto out;
 466         }
 467
 468         /* insert new cmb */
 469         list_add_tail(&cdev->private->cmb_list, &node->cmb_list);
 470         cmb_data->hw_block = cmb;
 471         cdev->private->cmb = cmb_data;
 472         ret = 0;
 473 out:
 474         spin_unlock_irq(cdev->ccwlock);
 475         return ret;
 476 }
 477
 478 static int alloc_cmb(struct ccw_device *cdev)
 479 {
 480         int ret;
 481         struct cmb *mem;
 482         ssize_t size;
 483         struct cmb_data *cmb_data;
 484
 485         /* Allocate private cmb_data. */
 486         cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
 487         if (!cmb_data)
 488                 return -ENOMEM;
 489
 490         cmb_data->last_block = kzalloc(sizeof(struct cmb), GFP_KERNEL);
 491         if (!cmb_data->last_block) {
 492                 kfree(cmb_data);
 493                 return -ENOMEM;
 494         }
 495         cmb_data->size = sizeof(struct cmb);
 496         spin_lock(&cmb_area.lock);
 497
 498         if (!cmb_area.mem) {
 499                 /* there is no user yet, so we need a new area */
 500                 size = sizeof(struct cmb) * cmb_area.num_channels;
 501                 WARN_ON(!list_empty(&cmb_area.list));
 502
 503                 spin_unlock(&cmb_area.lock);
 504                 mem = (void*)__get_free_pages(GFP_KERNEL | GFP_DMA,
 505                                  get_order(size));
 506                 spin_lock(&cmb_area.lock);
 507
 508                 if (cmb_area.mem) {
 509                         /* ok, another thread was faster */
 510                         free_pages((unsigned long)mem, get_order(size));
 511                 } else if (!mem) {
 512                         /* no luck */
 513                         ret = -ENOMEM;
 514                         goto out;
 515                 } else {
 516                         /* everything ok */
 517                         memset(mem, 0, size);
 518                         cmb_area.mem = mem;
 519                         cmf_activate(cmb_area.mem, CMF_ON);
 520                 }
 521         }
 522
 523         /* do the actual allocation */
 524         ret = alloc_cmb_single(cdev, cmb_data);
 525 out:
 526         spin_unlock(&cmb_area.lock);
 527         if (ret) {
 528                 kfree(cmb_data->last_block);
 529                 kfree(cmb_data);
 530         }
 531         return ret;
 532 }
 533
 534 static void free_cmb(struct ccw_device *cdev)
 535 {
 536         struct ccw_device_private *priv;
 537         struct cmb_data *cmb_data;
 538
 539         spin_lock(&cmb_area.lock);
 540         spin_lock_irq(cdev->ccwlock);
 541
 542         priv = cdev->private;
 543         cmb_data = priv->cmb;
 544         priv->cmb = NULL;
 545         if (cmb_data)
 546                 kfree(cmb_data->last_block);
 547         kfree(cmb_data);
 548         list_del_init(&priv->cmb_list);
 549
 550         if (list_empty(&cmb_area.list)) {
 551                 ssize_t size;
 552                 size = sizeof(struct cmb) * cmb_area.num_channels;
 553                 cmf_activate(NULL, CMF_OFF);
 554                 free_pages((unsigned long)cmb_area.mem, get_order(size));
 555                 cmb_area.mem = NULL;
 556         }
 557         spin_unlock_irq(cdev->ccwlock);
 558         spin_unlock(&cmb_area.lock);
 559 }
 560
 561 static int set_cmb(struct ccw_device *cdev, u32 mme)
 562 {
 563         u16 offset;
 564         struct cmb_data *cmb_data;
 565         unsigned long flags;
 566
 567         spin_lock_irqsave(cdev->ccwlock, flags);
 568         if (!cdev->private->cmb) {
 569                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 570                 return -EINVAL;
 571         }
 572         cmb_data = cdev->private->cmb;
 573         offset = mme ? (struct cmb *)cmb_data->hw_block - cmb_area.mem : 0;
 574         spin_unlock_irqrestore(cdev->ccwlock, flags);
 575
 576         return set_schib_wait(cdev, mme, 0, offset);
 577 }
 578
 579 /* calculate utilization in 0.1 percent units */
 580 static u64 __cmb_utilization(u64 device_connect_time, u64 function_pending_time,
 581                              u64 device_disconnect_time, u64 start_time)
 582 {
 583         u64 utilization, elapsed_time;
 584
 585         utilization = time_to_nsec(device_connect_time +
 586                                    function_pending_time +
 587                                    device_disconnect_time);
 588
 589         elapsed_time = get_tod_clock() - start_time;
 590         elapsed_time = tod_to_ns(elapsed_time);
 591         elapsed_time /= 1000;
 592
 593         return elapsed_time ? (utilization / elapsed_time) : 0;
 594 }
 595
 596 static u64 read_cmb(struct ccw_device *cdev, int index)
 597 {
 598         struct cmb_data *cmb_data;
 599         unsigned long flags;
 600         struct cmb *cmb;
 601         u64 ret = 0;
 602         u32 val;
 603
 604         spin_lock_irqsave(cdev->ccwlock, flags);
 605         cmb_data = cdev->private->cmb;
 606         if (!cmb_data)
 607                 goto out;
 608
 609         cmb = cmb_data->hw_block;
 610         switch (index) {
 611         case avg_utilization:
 612                 ret = __cmb_utilization(cmb->device_connect_time,
 613                                         cmb->function_pending_time,
 614                                         cmb->device_disconnect_time,
 615                                         cdev->private->cmb_start_time);
 616                 goto out;
 617         case cmb_ssch_rsch_count:
 618                 ret = cmb->ssch_rsch_count;
 619                 goto out;
 620         case cmb_sample_count:
 621                 ret = cmb->sample_count;
 622                 goto out;
 623         case cmb_device_connect_time:
 624                 val = cmb->device_connect_time;
 625                 break;
 626         case cmb_function_pending_time:
 627                 val = cmb->function_pending_time;
 628                 break;
 629         case cmb_device_disconnect_time:
 630                 val = cmb->device_disconnect_time;
 631                 break;
 632         case cmb_control_unit_queuing_time:
 633                 val = cmb->control_unit_queuing_time;
 634                 break;
 635         case cmb_device_active_only_time:
 636                 val = cmb->device_active_only_time;
 637                 break;
 638         default:
 639                 goto out;
 640         }
 641         ret = time_to_avg_nsec(val, cmb->sample_count);
 642 out:
 643         spin_unlock_irqrestore(cdev->ccwlock, flags);
 644         return ret;
 645 }
 646
 647 static int readall_cmb(struct ccw_device *cdev, struct cmbdata *data)
 648 {
 649         struct cmb *cmb;
 650         struct cmb_data *cmb_data;
 651         u64 time;
 652         unsigned long flags;
 653         int ret;
 654
 655         ret = cmf_cmb_copy_wait(cdev);
 656         if (ret < 0)
 657                 return ret;
 658         spin_lock_irqsave(cdev->ccwlock, flags);
 659         cmb_data = cdev->private->cmb;
 660         if (!cmb_data) {
 661                 ret = -ENODEV;
 662                 goto out;
 663         }
 664         if (cmb_data->last_update == 0) {
 665                 ret = -EAGAIN;
 666                 goto out;
 667         }
 668         cmb = cmb_data->last_block;
 669         time = cmb_data->last_update - cdev->private->cmb_start_time;
 670
 671         memset(data, 0, sizeof(struct cmbdata));
 672
 673         /* we only know values before device_busy_time */
 674         data->size = offsetof(struct cmbdata, device_busy_time);
 675
 676         data->elapsed_time = tod_to_ns(time);
 677
 678         /* copy data to new structure */
 679         data->ssch_rsch_count = cmb->ssch_rsch_count;
 680         data->sample_count = cmb->sample_count;
 681
 682         /* time fields are converted to nanoseconds while copying */
 683         data->device_connect_time = time_to_nsec(cmb->device_connect_time);
 684         data->function_pending_time = time_to_nsec(cmb->function_pending_time);
 685         data->device_disconnect_time =
 686                 time_to_nsec(cmb->device_disconnect_time);
 687         data->control_unit_queuing_time
 688                 = time_to_nsec(cmb->control_unit_queuing_time);
 689         data->device_active_only_time
 690                 = time_to_nsec(cmb->device_active_only_time);
 691         ret = 0;
 692 out:
 693         spin_unlock_irqrestore(cdev->ccwlock, flags);
 694         return ret;
 695 }
 696
 697 static void reset_cmb(struct ccw_device *cdev)
 698 {
 699         cmf_generic_reset(cdev);
 700 }
 701
 702 static int cmf_enabled(struct ccw_device *cdev)
 703 {
 704         int enabled;
 705
 706         spin_lock_irq(cdev->ccwlock);
 707         enabled = !!cdev->private->cmb;
 708         spin_unlock_irq(cdev->ccwlock);
 709
 710         return enabled;
 711 }
 712
 713 static struct attribute_group cmf_attr_group;
 714
 715 static struct cmb_operations cmbops_basic = {
 716         .alloc  = alloc_cmb,
 717         .free   = free_cmb,
 718         .set    = set_cmb,
 719         .read   = read_cmb,
 720         .readall    = readall_cmb,
 721         .reset      = reset_cmb,
 722         .attr_group = &cmf_attr_group,
 723 };
 724
 725 /* ******** extended cmb handling ********/
 726
 727 /**
 728  * struct cmbe - extended channel measurement block
 729  * @ssch_rsch_count: number of ssch and rsch
 730  * @sample_count: number of samples
 731  * @device_connect_time: time of device connect
 732  * @function_pending_time: time of function pending
 733  * @device_disconnect_time: time of device disconnect
 734  * @control_unit_queuing_time: time of control unit queuing
 735  * @device_active_only_time: time of device active only
 736  * @device_busy_time: time of device busy
 737  * @initial_command_response_time: initial command response time
 738  * @reserved: unused
 739  *
 740  * The measurement block as used by the hardware. May be in any 64 bit physical
 741  * location.
 742  * The fields are described further in z/Architecture Principles of Operation,
 743  * third edition, chapter 17.
 744  */
 745 struct cmbe {
 746         u32 ssch_rsch_count;
 747         u32 sample_count;
 748         u32 device_connect_time;
 749         u32 function_pending_time;
 750         u32 device_disconnect_time;
 751         u32 control_unit_queuing_time;
 752         u32 device_active_only_time;
 753         u32 device_busy_time;
 754         u32 initial_command_response_time;
 755         u32 reserved[7];
 756 } __packed __aligned(64);
 757
 758 static struct kmem_cache *cmbe_cache;
 759
 760 static int alloc_cmbe(struct ccw_device *cdev)
 761 {
 762         struct cmb_data *cmb_data;
 763         struct cmbe *cmbe;
 764         int ret = -ENOMEM;
 765
 766         cmbe = kmem_cache_zalloc(cmbe_cache, GFP_KERNEL);
 767         if (!cmbe)
 768                 return ret;
 769
 770         cmb_data = kzalloc(sizeof(*cmb_data), GFP_KERNEL);
 771         if (!cmb_data)
 772                 goto out_free;
 773
 774         cmb_data->last_block = kzalloc(sizeof(struct cmbe), GFP_KERNEL);
 775         if (!cmb_data->last_block)
 776                 goto out_free;
 777
 778         cmb_data->size = sizeof(*cmbe);
 779         cmb_data->hw_block = cmbe;
 780
 781         spin_lock(&cmb_area.lock);
 782         spin_lock_irq(cdev->ccwlock);
 783         if (cdev->private->cmb)
 784                 goto out_unlock;
 785
 786         cdev->private->cmb = cmb_data;
 787
 788         /* activate global measurement if this is the first channel */
 789         if (list_empty(&cmb_area.list))
 790                 cmf_activate(NULL, CMF_ON);
 791         list_add_tail(&cdev->private->cmb_list, &cmb_area.list);
 792
 793         spin_unlock_irq(cdev->ccwlock);
 794         spin_unlock(&cmb_area.lock);
 795         return 0;
 796
 797 out_unlock:
 798         spin_unlock_irq(cdev->ccwlock);
 799         spin_unlock(&cmb_area.lock);
 800         ret = -EBUSY;
 801 out_free:
 802         if (cmb_data)
 803                 kfree(cmb_data->last_block);
 804         kfree(cmb_data);
 805         kmem_cache_free(cmbe_cache, cmbe);
 806
 807         return ret;
 808 }
 809
 810 static void free_cmbe(struct ccw_device *cdev)
 811 {
 812         struct cmb_data *cmb_data;
 813
 814         spin_lock(&cmb_area.lock);
 815         spin_lock_irq(cdev->ccwlock);
 816         cmb_data = cdev->private->cmb;
 817         cdev->private->cmb = NULL;
 818         if (cmb_data) {
 819                 kfree(cmb_data->last_block);
 820                 kmem_cache_free(cmbe_cache, cmb_data->hw_block);
 821         }
 822         kfree(cmb_data);
 823
 824         /* deactivate global measurement if this is the last channel */
 825         list_del_init(&cdev->private->cmb_list);
 826         if (list_empty(&cmb_area.list))
 827                 cmf_activate(NULL, CMF_OFF);
 828         spin_unlock_irq(cdev->ccwlock);
 829         spin_unlock(&cmb_area.lock);
 830 }
 831
 832 static int set_cmbe(struct ccw_device *cdev, u32 mme)
 833 {
 834         unsigned long mba;
 835         struct cmb_data *cmb_data;
 836         unsigned long flags;
 837
 838         spin_lock_irqsave(cdev->ccwlock, flags);
 839         if (!cdev->private->cmb) {
 840                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 841                 return -EINVAL;
 842         }
 843         cmb_data = cdev->private->cmb;
 844         mba = mme ? (unsigned long) cmb_data->hw_block : 0;
 845         spin_unlock_irqrestore(cdev->ccwlock, flags);
 846
 847         return set_schib_wait(cdev, mme, 1, mba);
 848 }
 849
 850 static u64 read_cmbe(struct ccw_device *cdev, int index)
 851 {
 852         struct cmb_data *cmb_data;
 853         unsigned long flags;
 854         struct cmbe *cmb;
 855         u64 ret = 0;
 856         u32 val;
 857
 858         spin_lock_irqsave(cdev->ccwlock, flags);
 859         cmb_data = cdev->private->cmb;
 860         if (!cmb_data)
 861                 goto out;
 862
 863         cmb = cmb_data->hw_block;
 864         switch (index) {
 865         case avg_utilization:
 866                 ret = __cmb_utilization(cmb->device_connect_time,
 867                                         cmb->function_pending_time,
 868                                         cmb->device_disconnect_time,
 869                                         cdev->private->cmb_start_time);
 870                 goto out;
 871         case cmb_ssch_rsch_count:
 872                 ret = cmb->ssch_rsch_count;
 873                 goto out;
 874         case cmb_sample_count:
 875                 ret = cmb->sample_count;
 876                 goto out;
 877         case cmb_device_connect_time:
 878                 val = cmb->device_connect_time;
 879                 break;
 880         case cmb_function_pending_time:
 881                 val = cmb->function_pending_time;
 882                 break;
 883         case cmb_device_disconnect_time:
 884                 val = cmb->device_disconnect_time;
 885                 break;
 886         case cmb_control_unit_queuing_time:
 887                 val = cmb->control_unit_queuing_time;
 888                 break;
 889         case cmb_device_active_only_time:
 890                 val = cmb->device_active_only_time;
 891                 break;
 892         case cmb_device_busy_time:
 893                 val = cmb->device_busy_time;
 894                 break;
 895         case cmb_initial_command_response_time:
 896                 val = cmb->initial_command_response_time;
 897                 break;
 898         default:
 899                 goto out;
 900         }
 901         ret = time_to_avg_nsec(val, cmb->sample_count);
 902 out:
 903         spin_unlock_irqrestore(cdev->ccwlock, flags);
 904         return ret;
 905 }
 906
 907 static int readall_cmbe(struct ccw_device *cdev, struct cmbdata *data)
 908 {
 909         struct cmbe *cmb;
 910         struct cmb_data *cmb_data;
 911         u64 time;
 912         unsigned long flags;
 913         int ret;
 914
 915         ret = cmf_cmb_copy_wait(cdev);
 916         if (ret < 0)
 917                 return ret;
 918         spin_lock_irqsave(cdev->ccwlock, flags);
 919         cmb_data = cdev->private->cmb;
 920         if (!cmb_data) {
 921                 ret = -ENODEV;
 922                 goto out;
 923         }
 924         if (cmb_data->last_update == 0) {
 925                 ret = -EAGAIN;
 926                 goto out;
 927         }
 928         time = cmb_data->last_update - cdev->private->cmb_start_time;
 929
 930         memset (data, 0, sizeof(struct cmbdata));
 931
 932         /* we only know values before device_busy_time */
 933         data->size = offsetof(struct cmbdata, device_busy_time);
 934
 935         data->elapsed_time = tod_to_ns(time);
 936
 937         cmb = cmb_data->last_block;
 938         /* copy data to new structure */
 939         data->ssch_rsch_count = cmb->ssch_rsch_count;
 940         data->sample_count = cmb->sample_count;
 941
 942         /* time fields are converted to nanoseconds while copying */
 943         data->device_connect_time = time_to_nsec(cmb->device_connect_time);
 944         data->function_pending_time = time_to_nsec(cmb->function_pending_time);
 945         data->device_disconnect_time =
 946                 time_to_nsec(cmb->device_disconnect_time);
 947         data->control_unit_queuing_time
 948                 = time_to_nsec(cmb->control_unit_queuing_time);
 949         data->device_active_only_time
 950                 = time_to_nsec(cmb->device_active_only_time);
 951         data->device_busy_time = time_to_nsec(cmb->device_busy_time);
 952         data->initial_command_response_time
 953                 = time_to_nsec(cmb->initial_command_response_time);
 954
 955         ret = 0;
 956 out:
 957         spin_unlock_irqrestore(cdev->ccwlock, flags);
 958         return ret;
 959 }
 960
 961 static void reset_cmbe(struct ccw_device *cdev)
 962 {
 963         cmf_generic_reset(cdev);
 964 }
 965
 966 static struct attribute_group cmf_attr_group_ext;
 967
 968 static struct cmb_operations cmbops_extended = {
 969         .alloc      = alloc_cmbe,
 970         .free       = free_cmbe,
 971         .set        = set_cmbe,
 972         .read       = read_cmbe,
 973         .readall    = readall_cmbe,
 974         .reset      = reset_cmbe,
 975         .attr_group = &cmf_attr_group_ext,
 976 };
 977
 978 static ssize_t cmb_show_attr(struct device *dev, char *buf, enum cmb_index idx)
 979 {
 980         return sprintf(buf, "%lld\n",
 981                 (unsigned long long) cmf_read(to_ccwdev(dev), idx));
 982 }
 983
 984 static ssize_t cmb_show_avg_sample_interval(struct device *dev,
 985                                             struct device_attribute *attr,
 986                                             char *buf)
 987 {
 988         struct ccw_device *cdev = to_ccwdev(dev);
 989         unsigned long count;
 990         long interval;
 991
 992         count = cmf_read(cdev, cmb_sample_count);
 993         spin_lock_irq(cdev->ccwlock);
 994         if (count) {
 995                 interval = get_tod_clock() - cdev->private->cmb_start_time;
 996                 interval = tod_to_ns(interval);
 997                 interval /= count;
 998         } else
 999                 interval = -1;
1000         spin_unlock_irq(cdev->ccwlock);
1001         return sprintf(buf, "%ld\n", interval);
1002 }
1003
1004 static ssize_t cmb_show_avg_utilization(struct device *dev,
1005                                         struct device_attribute *attr,
1006                                         char *buf)
1007 {
1008         unsigned long u = cmf_read(to_ccwdev(dev), avg_utilization);
1009
1010         return sprintf(buf, "%02lu.%01lu%%\n", u / 10, u % 10);
1011 }
1012
1013 #define cmf_attr(name) \
1014 static ssize_t show_##name(struct device *dev, \
1015                            struct device_attribute *attr, char *buf)    \
1016 { return cmb_show_attr((dev), buf, cmb_##name); } \
1017 static DEVICE_ATTR(name, 0444, show_##name, NULL);
1018
1019 #define cmf_attr_avg(name) \
1020 static ssize_t show_avg_##name(struct device *dev, \
1021                                struct device_attribute *attr, char *buf) \
1022 { return cmb_show_attr((dev), buf, cmb_##name); } \
1023 static DEVICE_ATTR(avg_##name, 0444, show_avg_##name, NULL);
1024
1025 cmf_attr(ssch_rsch_count);
1026 cmf_attr(sample_count);
1027 cmf_attr_avg(device_connect_time);
1028 cmf_attr_avg(function_pending_time);
1029 cmf_attr_avg(device_disconnect_time);
1030 cmf_attr_avg(control_unit_queuing_time);
1031 cmf_attr_avg(device_active_only_time);
1032 cmf_attr_avg(device_busy_time);
1033 cmf_attr_avg(initial_command_response_time);
1034
1035 static DEVICE_ATTR(avg_sample_interval, 0444, cmb_show_avg_sample_interval,
1036                    NULL);
1037 static DEVICE_ATTR(avg_utilization, 0444, cmb_show_avg_utilization, NULL);
1038
1039 static struct attribute *cmf_attributes[] = {
1040         &dev_attr_avg_sample_interval.attr,
1041         &dev_attr_avg_utilization.attr,
1042         &dev_attr_ssch_rsch_count.attr,
1043         &dev_attr_sample_count.attr,
1044         &dev_attr_avg_device_connect_time.attr,
1045         &dev_attr_avg_function_pending_time.attr,
1046         &dev_attr_avg_device_disconnect_time.attr,
1047         &dev_attr_avg_control_unit_queuing_time.attr,
1048         &dev_attr_avg_device_active_only_time.attr,
1049         NULL,
1050 };
1051
1052 static struct attribute_group cmf_attr_group = {
1053         .name  = "cmf",
1054         .attrs = cmf_attributes,
1055 };
1056
1057 static struct attribute *cmf_attributes_ext[] = {
1058         &dev_attr_avg_sample_interval.attr,
1059         &dev_attr_avg_utilization.attr,
1060         &dev_attr_ssch_rsch_count.attr,
1061         &dev_attr_sample_count.attr,
1062         &dev_attr_avg_device_connect_time.attr,
1063         &dev_attr_avg_function_pending_time.attr,
1064         &dev_attr_avg_device_disconnect_time.attr,
1065         &dev_attr_avg_control_unit_queuing_time.attr,
1066         &dev_attr_avg_device_active_only_time.attr,
1067         &dev_attr_avg_device_busy_time.attr,
1068         &dev_attr_avg_initial_command_response_time.attr,
1069         NULL,
1070 };
1071
1072 static struct attribute_group cmf_attr_group_ext = {
1073         .name  = "cmf",
1074         .attrs = cmf_attributes_ext,
1075 };
1076
1077 static ssize_t cmb_enable_show(struct device *dev,
1078                                struct device_attribute *attr,
1079                                char *buf)
1080 {
1081         struct ccw_device *cdev = to_ccwdev(dev);
1082
1083         return sprintf(buf, "%d\n", cmf_enabled(cdev));
1084 }
1085
1086 static ssize_t cmb_enable_store(struct device *dev,
1087                                 struct device_attribute *attr, const char *buf,
1088                                 size_t c)
1089 {
1090         struct ccw_device *cdev = to_ccwdev(dev);
1091         unsigned long val;
1092         int ret;
1093
1094         ret = kstrtoul(buf, 16, &val);
1095         if (ret)
1096                 return ret;
1097
1098         switch (val) {
1099         case 0:
1100                 ret = disable_cmf(cdev);
1101                 break;
1102         case 1:
1103                 ret = enable_cmf(cdev);
1104                 break;
1105         default:
1106                 ret = -EINVAL;
1107         }
1108
1109         return ret ? ret : c;
1110 }
1111 DEVICE_ATTR_RW(cmb_enable);
1112
1113 /**
1114  * enable_cmf() - switch on the channel measurement for a specific device
1115  *  @cdev:      The ccw device to be enabled
1116  *
1117  *  Enable channel measurements for @cdev. If this is called on a device
1118  *  for which channel measurement is already enabled a reset of the
1119  *  measurement data is triggered.
1120  *  Returns: %0 for success or a negative error value.
1121  *  Context:
1122  *    non-atomic
1123  */
1124 int enable_cmf(struct ccw_device *cdev)
1125 {
1126         int ret = 0;
1127
1128         device_lock(&cdev->dev);
1129         if (cmf_enabled(cdev)) {
1130                 cmbops->reset(cdev);
1131                 goto out_unlock;
1132         }
1133         get_device(&cdev->dev);
1134         ret = cmbops->alloc(cdev);
1135         if (ret)
1136                 goto out;
1137         cmbops->reset(cdev);
1138         ret = sysfs_create_group(&cdev->dev.kobj, cmbops->attr_group);
1139         if (ret) {
1140                 cmbops->free(cdev);
1141                 goto out;
1142         }
1143         ret = cmbops->set(cdev, 2);
1144         if (ret) {
1145                 sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
1146                 cmbops->free(cdev);
1147         }
1148 out:
1149         if (ret)
1150                 put_device(&cdev->dev);
1151 out_unlock:
1152         device_unlock(&cdev->dev);
1153         return ret;
1154 }
1155
1156 /**
1157  * __disable_cmf() - switch off the channel measurement for a specific device
1158  *  @cdev:      The ccw device to be disabled
1159  *
1160  *  Returns: %0 for success or a negative error value.
1161  *
1162  *  Context:
1163  *    non-atomic, device_lock() held.
1164  */
1165 int __disable_cmf(struct ccw_device *cdev)
1166 {
1167         int ret;
1168
1169         ret = cmbops->set(cdev, 0);
1170         if (ret)
1171                 return ret;
1172
1173         sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
1174         cmbops->free(cdev);
1175         put_device(&cdev->dev);
1176
1177         return ret;
1178 }
1179
1180 /**
1181  * disable_cmf() - switch off the channel measurement for a specific device
1182  *  @cdev:      The ccw device to be disabled
1183  *
1184  *  Returns: %0 for success or a negative error value.
1185  *
1186  *  Context:
1187  *    non-atomic
1188  */
1189 int disable_cmf(struct ccw_device *cdev)
1190 {
1191         int ret;
1192
1193         device_lock(&cdev->dev);
1194         ret = __disable_cmf(cdev);
1195         device_unlock(&cdev->dev);
1196
1197         return ret;
1198 }
1199
1200 /**
1201  * cmf_read() - read one value from the current channel measurement block
1202  * @cdev:       the channel to be read
1203  * @index:      the index of the value to be read
1204  *
1205  * Returns: The value read or %0 if the value cannot be read.
1206  *
1207  *  Context:
1208  *    any
1209  */
1210 u64 cmf_read(struct ccw_device *cdev, int index)
1211 {
1212         return cmbops->read(cdev, index);
1213 }
1214
1215 /**
1216  * cmf_readall() - read the current channel measurement block
1217  * @cdev:       the channel to be read
1218  * @data:       a pointer to a data block that will be filled
1219  *
1220  * Returns: %0 on success, a negative error value otherwise.
1221  *
1222  *  Context:
1223  *    any
1224  */
1225 int cmf_readall(struct ccw_device *cdev, struct cmbdata *data)
1226 {
1227         return cmbops->readall(cdev, data);
1228 }
1229
1230 /* Reenable cmf when a disconnected device becomes available again. */
1231 int cmf_reenable(struct ccw_device *cdev)
1232 {
1233         cmbops->reset(cdev);
1234         return cmbops->set(cdev, 2);
1235 }
1236
1237 /**
1238  * cmf_reactivate() - reactivate measurement block updates
1239  *
1240  * Use this during resume from hibernate.
1241  */
1242 void cmf_reactivate(void)
1243 {
1244         spin_lock(&cmb_area.lock);
1245         if (!list_empty(&cmb_area.list))
1246                 cmf_activate(cmb_area.mem, CMF_ON);
1247         spin_unlock(&cmb_area.lock);
1248 }
1249
1250 static int __init init_cmbe(void)
1251 {
1252         cmbe_cache = kmem_cache_create("cmbe_cache", sizeof(struct cmbe),
1253                                        __alignof__(struct cmbe), 0, NULL);
1254
1255         return cmbe_cache ? 0 : -ENOMEM;
1256 }
1257
1258 static int __init init_cmf(void)
1259 {
1260         char *format_string;
1261         char *detect_string;
1262         int ret;
1263
1264         /*
1265          * If the user did not give a parameter, see if we are running on a
1266          * machine supporting extended measurement blocks, otherwise fall back
1267          * to basic mode.
1268          */
1269         if (format == CMF_AUTODETECT) {
1270                 if (!css_general_characteristics.ext_mb) {
1271                         format = CMF_BASIC;
1272                 } else {
1273                         format = CMF_EXTENDED;
1274                 }
1275                 detect_string = "autodetected";
1276         } else {
1277                 detect_string = "parameter";
1278         }
1279
1280         switch (format) {
1281         case CMF_BASIC:
1282                 format_string = "basic";
1283                 cmbops = &cmbops_basic;
1284                 break;
1285         case CMF_EXTENDED:
1286                 format_string = "extended";
1287                 cmbops = &cmbops_extended;
1288
1289                 ret = init_cmbe();
1290                 if (ret)
1291                         return ret;
1292                 break;
1293         default:
1294                 return -EINVAL;
1295         }
1296         pr_info("Channel measurement facility initialized using format "
1297                 "%s (mode %s)\n", format_string, detect_string);
1298         return 0;
1299 }
1300 device_initcall(init_cmf);
1301
1302 EXPORT_SYMBOL_GPL(enable_cmf);
1303 EXPORT_SYMBOL_GPL(disable_cmf);
1304 EXPORT_SYMBOL_GPL(cmf_read);
1305 EXPORT_SYMBOL_GPL(cmf_readall);