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 extended 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 single 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),
 173                   [mbo] "d" (virt_to_phys(area))
 174                 : "1", "2");
 175 }
 176
 177 static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
 178                      unsigned long address)
 179 {
 180         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 181         int ret;
 182
 183         sch->config.mme = mme;
 184         sch->config.mbfc = mbfc;
 185         /* address can be either a block address or a block index */
 186         if (mbfc)
 187                 sch->config.mba = address;
 188         else
 189                 sch->config.mbi = address;
 190
 191         ret = cio_commit_config(sch);
 192         if (!mme && ret == -ENODEV) {
 193                 /*
 194                  * The task was to disable measurement block updates but
 195                  * the subchannel is already gone. Report success.
 196                  */
 197                 ret = 0;
 198         }
 199         return ret;
 200 }
 201
 202 struct set_schib_struct {
 203         u32 mme;
 204         int mbfc;
 205         unsigned long address;
 206         wait_queue_head_t wait;
 207         int ret;
 208 };
 209
 210 #define CMF_PENDING 1
 211 #define SET_SCHIB_TIMEOUT (10 * HZ)
 212
 213 static int set_schib_wait(struct ccw_device *cdev, u32 mme,
 214                           int mbfc, unsigned long address)
 215 {
 216         struct set_schib_struct set_data;
 217         int ret = -ENODEV;
 218
 219         spin_lock_irq(cdev->ccwlock);
 220         if (!cdev->private->cmb)
 221                 goto out;
 222
 223         ret = set_schib(cdev, mme, mbfc, address);
 224         if (ret != -EBUSY)
 225                 goto out;
 226
 227         /* if the device is not online, don't even try again */
 228         if (cdev->private->state != DEV_STATE_ONLINE)
 229                 goto out;
 230
 231         init_waitqueue_head(&set_data.wait);
 232         set_data.mme = mme;
 233         set_data.mbfc = mbfc;
 234         set_data.address = address;
 235         set_data.ret = CMF_PENDING;
 236
 237         cdev->private->state = DEV_STATE_CMFCHANGE;
 238         cdev->private->cmb_wait = &set_data;
 239         spin_unlock_irq(cdev->ccwlock);
 240
 241         ret = wait_event_interruptible_timeout(set_data.wait,
 242                                                set_data.ret != CMF_PENDING,
 243                                                SET_SCHIB_TIMEOUT);
 244         spin_lock_irq(cdev->ccwlock);
 245         if (ret <= 0) {
 246                 if (set_data.ret == CMF_PENDING) {
 247                         set_data.ret = (ret == 0) ? -ETIME : ret;
 248                         if (cdev->private->state == DEV_STATE_CMFCHANGE)
 249                                 cdev->private->state = DEV_STATE_ONLINE;
 250                 }
 251         }
 252         cdev->private->cmb_wait = NULL;
 253         ret = set_data.ret;
 254 out:
 255         spin_unlock_irq(cdev->ccwlock);
 256         return ret;
 257 }
 258
 259 void retry_set_schib(struct ccw_device *cdev)
 260 {
 261         struct set_schib_struct *set_data = cdev->private->cmb_wait;
 262
 263         if (!set_data)
 264                 return;
 265
 266         set_data->ret = set_schib(cdev, set_data->mme, set_data->mbfc,
 267                                   set_data->address);
 268         wake_up(&set_data->wait);
 269 }
 270
 271 static int cmf_copy_block(struct ccw_device *cdev)
 272 {
 273         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 274         struct cmb_data *cmb_data;
 275         void *hw_block;
 276
 277         if (cio_update_schib(sch))
 278                 return -ENODEV;
 279
 280         if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
 281                 /* Don't copy if a start function is in progress. */
 282                 if ((!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_SUSPENDED)) &&
 283                     (scsw_actl(&sch->schib.scsw) &
 284                      (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) &&
 285                     (!(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_SEC_STATUS)))
 286                         return -EBUSY;
 287         }
 288         cmb_data = cdev->private->cmb;
 289         hw_block = cmb_data->hw_block;
 290         memcpy(cmb_data->last_block, hw_block, cmb_data->size);
 291         cmb_data->last_update = get_tod_clock();
 292         return 0;
 293 }
 294
 295 struct copy_block_struct {
 296         wait_queue_head_t wait;
 297         int ret;
 298 };
 299
 300 static int cmf_cmb_copy_wait(struct ccw_device *cdev)
 301 {
 302         struct copy_block_struct copy_block;
 303         int ret = -ENODEV;
 304
 305         spin_lock_irq(cdev->ccwlock);
 306         if (!cdev->private->cmb)
 307                 goto out;
 308
 309         ret = cmf_copy_block(cdev);
 310         if (ret != -EBUSY)
 311                 goto out;
 312
 313         if (cdev->private->state != DEV_STATE_ONLINE)
 314                 goto out;
 315
 316         init_waitqueue_head(&copy_block.wait);
 317         copy_block.ret = CMF_PENDING;
 318
 319         cdev->private->state = DEV_STATE_CMFUPDATE;
 320         cdev->private->cmb_wait = &copy_block;
 321         spin_unlock_irq(cdev->ccwlock);
 322
 323         ret = wait_event_interruptible(copy_block.wait,
 324                                        copy_block.ret != CMF_PENDING);
 325         spin_lock_irq(cdev->ccwlock);
 326         if (ret) {
 327                 if (copy_block.ret == CMF_PENDING) {
 328                         copy_block.ret = -ERESTARTSYS;
 329                         if (cdev->private->state == DEV_STATE_CMFUPDATE)
 330                                 cdev->private->state = DEV_STATE_ONLINE;
 331                 }
 332         }
 333         cdev->private->cmb_wait = NULL;
 334         ret = copy_block.ret;
 335 out:
 336         spin_unlock_irq(cdev->ccwlock);
 337         return ret;
 338 }
 339
 340 void cmf_retry_copy_block(struct ccw_device *cdev)
 341 {
 342         struct copy_block_struct *copy_block = cdev->private->cmb_wait;
 343
 344         if (!copy_block)
 345                 return;
 346
 347         copy_block->ret = cmf_copy_block(cdev);
 348         wake_up(&copy_block->wait);
 349 }
 350
 351 static void cmf_generic_reset(struct ccw_device *cdev)
 352 {
 353         struct cmb_data *cmb_data;
 354
 355         spin_lock_irq(cdev->ccwlock);
 356         cmb_data = cdev->private->cmb;
 357         if (cmb_data) {
 358                 memset(cmb_data->last_block, 0, cmb_data->size);
 359                 /*
 360                  * Need to reset hw block as well to make the hardware start
 361                  * from 0 again.
 362                  */
 363                 memset(cmb_data->hw_block, 0, cmb_data->size);
 364                 cmb_data->last_update = 0;
 365         }
 366         cdev->private->cmb_start_time = get_tod_clock();
 367         spin_unlock_irq(cdev->ccwlock);
 368 }
 369
 370 /**
 371  * struct cmb_area - container for global cmb data
 372  *
 373  * @mem:        pointer to CMBs (only in basic measurement mode)
 374  * @list:       contains a linked list of all subchannels
 375  * @num_channels: number of channels to be measured
 376  * @lock:       protect concurrent access to @mem and @list
 377  */
 378 struct cmb_area {
 379         struct cmb *mem;
 380         struct list_head list;
 381         int num_channels;
 382         spinlock_t lock;
 383 };
 384
 385 static struct cmb_area cmb_area = {
 386         .lock = __SPIN_LOCK_UNLOCKED(cmb_area.lock),
 387         .list = LIST_HEAD_INIT(cmb_area.list),
 388         .num_channels  = 1024,
 389 };
 390
 391 /* ****** old style CMB handling ********/
 392
 393 /*
 394  * Basic channel measurement blocks are allocated in one contiguous
 395  * block of memory, which can not be moved as long as any channel
 396  * is active. Therefore, a maximum number of subchannels needs to
 397  * be defined somewhere. This is a module parameter, defaulting to
 398  * a reasonable value of 1024, or 32 kb of memory.
 399  * Current kernels don't allow kmalloc with more than 128kb, so the
 400  * maximum is 4096.
 401  */
 402
 403 module_param_named(maxchannels, cmb_area.num_channels, uint, 0444);
 404
 405 /**
 406  * struct cmb - basic channel measurement block
 407  * @ssch_rsch_count: number of ssch and rsch
 408  * @sample_count: number of samples
 409  * @device_connect_time: time of device connect
 410  * @function_pending_time: time of function pending
 411  * @device_disconnect_time: time of device disconnect
 412  * @control_unit_queuing_time: time of control unit queuing
 413  * @device_active_only_time: time of device active only
 414  * @reserved: unused in basic measurement mode
 415  *
 416  * The measurement block as used by the hardware. The fields are described
 417  * further in z/Architecture Principles of Operation, chapter 17.
 418  *
 419  * The cmb area made up from these blocks must be a contiguous array and may
 420  * not be reallocated or freed.
 421  * Only one cmb area can be present in the system.
 422  */
 423 struct cmb {
 424         u16 ssch_rsch_count;
 425         u16 sample_count;
 426         u32 device_connect_time;
 427         u32 function_pending_time;
 428         u32 device_disconnect_time;
 429         u32 control_unit_queuing_time;
 430         u32 device_active_only_time;
 431         u32 reserved[2];
 432 };
 433
 434 /*
 435  * Insert a single device into the cmb_area list.
 436  * Called with cmb_area.lock held from alloc_cmb.
 437  */
 438 static int alloc_cmb_single(struct ccw_device *cdev,
 439                             struct cmb_data *cmb_data)
 440 {
 441         struct cmb *cmb;
 442         struct ccw_device_private *node;
 443         int ret;
 444
 445         spin_lock_irq(cdev->ccwlock);
 446         if (!list_empty(&cdev->private->cmb_list)) {
 447                 ret = -EBUSY;
 448                 goto out;
 449         }
 450
 451         /*
 452          * Find first unused cmb in cmb_area.mem.
 453          * This is a little tricky: cmb_area.list
 454          * remains sorted by ->cmb->hw_data pointers.
 455          */
 456         cmb = cmb_area.mem;
 457         list_for_each_entry(node, &cmb_area.list, cmb_list) {
 458                 struct cmb_data *data;
 459                 data = node->cmb;
 460                 if ((struct cmb*)data->hw_block > cmb)
 461                         break;
 462                 cmb++;
 463         }
 464         if (cmb - cmb_area.mem >= cmb_area.num_channels) {
 465                 ret = -ENOMEM;
 466                 goto out;
 467         }
 468
 469         /* insert new cmb */
 470         list_add_tail(&cdev->private->cmb_list, &node->cmb_list);
 471         cmb_data->hw_block = cmb;
 472         cdev->private->cmb = cmb_data;
 473         ret = 0;
 474 out:
 475         spin_unlock_irq(cdev->ccwlock);
 476         return ret;
 477 }
 478
 479 static int alloc_cmb(struct ccw_device *cdev)
 480 {
 481         int ret;
 482         struct cmb *mem;
 483         ssize_t size;
 484         struct cmb_data *cmb_data;
 485
 486         /* Allocate private cmb_data. */
 487         cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
 488         if (!cmb_data)
 489                 return -ENOMEM;
 490
 491         cmb_data->last_block = kzalloc(sizeof(struct cmb), GFP_KERNEL);
 492         if (!cmb_data->last_block) {
 493                 kfree(cmb_data);
 494                 return -ENOMEM;
 495         }
 496         cmb_data->size = sizeof(struct cmb);
 497         spin_lock(&cmb_area.lock);
 498
 499         if (!cmb_area.mem) {
 500                 /* there is no user yet, so we need a new area */
 501                 size = sizeof(struct cmb) * cmb_area.num_channels;
 502                 WARN_ON(!list_empty(&cmb_area.list));
 503
 504                 spin_unlock(&cmb_area.lock);
 505                 mem = (void *)__get_free_pages(GFP_KERNEL, 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 sysfs_emit(buf, "%lld\n", cmf_read(to_ccwdev(dev), idx));
 981 }
 982
 983 static ssize_t cmb_show_avg_sample_interval(struct device *dev,
 984                                             struct device_attribute *attr,
 985                                             char *buf)
 986 {
 987         struct ccw_device *cdev = to_ccwdev(dev);
 988         unsigned long count;
 989         long interval;
 990
 991         count = cmf_read(cdev, cmb_sample_count);
 992         spin_lock_irq(cdev->ccwlock);
 993         if (count) {
 994                 interval = get_tod_clock() - cdev->private->cmb_start_time;
 995                 interval = tod_to_ns(interval);
 996                 interval /= count;
 997         } else
 998                 interval = -1;
 999         spin_unlock_irq(cdev->ccwlock);
1000         return sysfs_emit(buf, "%ld\n", interval);
1001 }
1002
1003 static ssize_t cmb_show_avg_utilization(struct device *dev,
1004                                         struct device_attribute *attr,
1005                                         char *buf)
1006 {
1007         unsigned long u = cmf_read(to_ccwdev(dev), avg_utilization);
1008
1009         return sysfs_emit(buf, "%02lu.%01lu%%\n", u / 10, u % 10);
1010 }
1011
1012 #define cmf_attr(name) \
1013 static ssize_t show_##name(struct device *dev, \
1014                            struct device_attribute *attr, char *buf)    \
1015 { return cmb_show_attr((dev), buf, cmb_##name); } \
1016 static DEVICE_ATTR(name, 0444, show_##name, NULL);
1017
1018 #define cmf_attr_avg(name) \
1019 static ssize_t show_avg_##name(struct device *dev, \
1020                                struct device_attribute *attr, char *buf) \
1021 { return cmb_show_attr((dev), buf, cmb_##name); } \
1022 static DEVICE_ATTR(avg_##name, 0444, show_avg_##name, NULL);
1023
1024 cmf_attr(ssch_rsch_count);
1025 cmf_attr(sample_count);
1026 cmf_attr_avg(device_connect_time);
1027 cmf_attr_avg(function_pending_time);
1028 cmf_attr_avg(device_disconnect_time);
1029 cmf_attr_avg(control_unit_queuing_time);
1030 cmf_attr_avg(device_active_only_time);
1031 cmf_attr_avg(device_busy_time);
1032 cmf_attr_avg(initial_command_response_time);
1033
1034 static DEVICE_ATTR(avg_sample_interval, 0444, cmb_show_avg_sample_interval,
1035                    NULL);
1036 static DEVICE_ATTR(avg_utilization, 0444, cmb_show_avg_utilization, NULL);
1037
1038 static struct attribute *cmf_attributes[] = {
1039         &dev_attr_avg_sample_interval.attr,
1040         &dev_attr_avg_utilization.attr,
1041         &dev_attr_ssch_rsch_count.attr,
1042         &dev_attr_sample_count.attr,
1043         &dev_attr_avg_device_connect_time.attr,
1044         &dev_attr_avg_function_pending_time.attr,
1045         &dev_attr_avg_device_disconnect_time.attr,
1046         &dev_attr_avg_control_unit_queuing_time.attr,
1047         &dev_attr_avg_device_active_only_time.attr,
1048         NULL,
1049 };
1050
1051 static struct attribute_group cmf_attr_group = {
1052         .name  = "cmf",
1053         .attrs = cmf_attributes,
1054 };
1055
1056 static struct attribute *cmf_attributes_ext[] = {
1057         &dev_attr_avg_sample_interval.attr,
1058         &dev_attr_avg_utilization.attr,
1059         &dev_attr_ssch_rsch_count.attr,
1060         &dev_attr_sample_count.attr,
1061         &dev_attr_avg_device_connect_time.attr,
1062         &dev_attr_avg_function_pending_time.attr,
1063         &dev_attr_avg_device_disconnect_time.attr,
1064         &dev_attr_avg_control_unit_queuing_time.attr,
1065         &dev_attr_avg_device_active_only_time.attr,
1066         &dev_attr_avg_device_busy_time.attr,
1067         &dev_attr_avg_initial_command_response_time.attr,
1068         NULL,
1069 };
1070
1071 static struct attribute_group cmf_attr_group_ext = {
1072         .name  = "cmf",
1073         .attrs = cmf_attributes_ext,
1074 };
1075
1076 static ssize_t cmb_enable_show(struct device *dev,
1077                                struct device_attribute *attr,
1078                                char *buf)
1079 {
1080         struct ccw_device *cdev = to_ccwdev(dev);
1081
1082         return sysfs_emit(buf, "%d\n", cmf_enabled(cdev));
1083 }
1084
1085 static ssize_t cmb_enable_store(struct device *dev,
1086                                 struct device_attribute *attr, const char *buf,
1087                                 size_t c)
1088 {
1089         struct ccw_device *cdev = to_ccwdev(dev);
1090         unsigned long val;
1091         int ret;
1092
1093         ret = kstrtoul(buf, 16, &val);
1094         if (ret)
1095                 return ret;
1096
1097         switch (val) {
1098         case 0:
1099                 ret = disable_cmf(cdev);
1100                 break;
1101         case 1:
1102                 ret = enable_cmf(cdev);
1103                 break;
1104         default:
1105                 ret = -EINVAL;
1106         }
1107
1108         return ret ? ret : c;
1109 }
1110 DEVICE_ATTR_RW(cmb_enable);
1111
1112 /**
1113  * enable_cmf() - switch on the channel measurement for a specific device
1114  *  @cdev:      The ccw device to be enabled
1115  *
1116  *  Enable channel measurements for @cdev. If this is called on a device
1117  *  for which channel measurement is already enabled a reset of the
1118  *  measurement data is triggered.
1119  *  Returns: %0 for success or a negative error value.
1120  *  Context:
1121  *    non-atomic
1122  */
1123 int enable_cmf(struct ccw_device *cdev)
1124 {
1125         int ret = 0;
1126
1127         device_lock(&cdev->dev);
1128         if (cmf_enabled(cdev)) {
1129                 cmbops->reset(cdev);
1130                 goto out_unlock;
1131         }
1132         get_device(&cdev->dev);
1133         ret = cmbops->alloc(cdev);
1134         if (ret)
1135                 goto out;
1136         cmbops->reset(cdev);
1137         ret = sysfs_create_group(&cdev->dev.kobj, cmbops->attr_group);
1138         if (ret) {
1139                 cmbops->free(cdev);
1140                 goto out;
1141         }
1142         ret = cmbops->set(cdev, 2);
1143         if (ret) {
1144                 sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
1145                 cmbops->free(cdev);
1146         }
1147 out:
1148         if (ret)
1149                 put_device(&cdev->dev);
1150 out_unlock:
1151         device_unlock(&cdev->dev);
1152         return ret;
1153 }
1154
1155 /**
1156  * __disable_cmf() - switch off the channel measurement for a specific device
1157  *  @cdev:      The ccw device to be disabled
1158  *
1159  *  Returns: %0 for success or a negative error value.
1160  *
1161  *  Context:
1162  *    non-atomic, device_lock() held.
1163  */
1164 int __disable_cmf(struct ccw_device *cdev)
1165 {
1166         int ret;
1167
1168         ret = cmbops->set(cdev, 0);
1169         if (ret)
1170                 return ret;
1171
1172         sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
1173         cmbops->free(cdev);
1174         put_device(&cdev->dev);
1175
1176         return ret;
1177 }
1178
1179 /**
1180  * disable_cmf() - switch off the channel measurement for a specific device
1181  *  @cdev:      The ccw device to be disabled
1182  *
1183  *  Returns: %0 for success or a negative error value.
1184  *
1185  *  Context:
1186  *    non-atomic
1187  */
1188 int disable_cmf(struct ccw_device *cdev)
1189 {
1190         int ret;
1191
1192         device_lock(&cdev->dev);
1193         ret = __disable_cmf(cdev);
1194         device_unlock(&cdev->dev);
1195
1196         return ret;
1197 }
1198
1199 /**
1200  * cmf_read() - read one value from the current channel measurement block
1201  * @cdev:       the channel to be read
1202  * @index:      the index of the value to be read
1203  *
1204  * Returns: The value read or %0 if the value cannot be read.
1205  *
1206  *  Context:
1207  *    any
1208  */
1209 u64 cmf_read(struct ccw_device *cdev, int index)
1210 {
1211         return cmbops->read(cdev, index);
1212 }
1213
1214 /**
1215  * cmf_readall() - read the current channel measurement block
1216  * @cdev:       the channel to be read
1217  * @data:       a pointer to a data block that will be filled
1218  *
1219  * Returns: %0 on success, a negative error value otherwise.
1220  *
1221  *  Context:
1222  *    any
1223  */
1224 int cmf_readall(struct ccw_device *cdev, struct cmbdata *data)
1225 {
1226         return cmbops->readall(cdev, data);
1227 }
1228
1229 /* Re-enable cmf when a disconnected device becomes available again. */
1230 int cmf_reenable(struct ccw_device *cdev)
1231 {
1232         cmbops->reset(cdev);
1233         return cmbops->set(cdev, 2);
1234 }
1235
1236 /**
1237  * cmf_reactivate() - reactivate measurement block updates
1238  *
1239  * Use this during resume from hibernate.
1240  */
1241 void cmf_reactivate(void)
1242 {
1243         spin_lock(&cmb_area.lock);
1244         if (!list_empty(&cmb_area.list))
1245                 cmf_activate(cmb_area.mem, CMF_ON);
1246         spin_unlock(&cmb_area.lock);
1247 }
1248
1249 static int __init init_cmbe(void)
1250 {
1251         cmbe_cache = kmem_cache_create("cmbe_cache", sizeof(struct cmbe),
1252                                        __alignof__(struct cmbe), 0, NULL);
1253
1254         return cmbe_cache ? 0 : -ENOMEM;
1255 }
1256
1257 static int __init init_cmf(void)
1258 {
1259         char *format_string;
1260         char *detect_string;
1261         int ret;
1262
1263         /*
1264          * If the user did not give a parameter, see if we are running on a
1265          * machine supporting extended measurement blocks, otherwise fall back
1266          * to basic mode.
1267          */
1268         if (format == CMF_AUTODETECT) {
1269                 if (!css_general_characteristics.ext_mb) {
1270                         format = CMF_BASIC;
1271                 } else {
1272                         format = CMF_EXTENDED;
1273                 }
1274                 detect_string = "autodetected";
1275         } else {
1276                 detect_string = "parameter";
1277         }
1278
1279         switch (format) {
1280         case CMF_BASIC:
1281                 format_string = "basic";
1282                 cmbops = &cmbops_basic;
1283                 break;
1284         case CMF_EXTENDED:
1285                 format_string = "extended";
1286                 cmbops = &cmbops_extended;
1287
1288                 ret = init_cmbe();
1289                 if (ret)
1290                         return ret;
1291                 break;
1292         default:
1293                 return -EINVAL;
1294         }
1295         pr_info("Channel measurement facility initialized using format "
1296                 "%s (mode %s)\n", format_string, detect_string);
1297         return 0;
1298 }
1299 device_initcall(init_cmf);
1300
1301 EXPORT_SYMBOL_GPL(enable_cmf);
1302 EXPORT_SYMBOL_GPL(disable_cmf);
1303 EXPORT_SYMBOL_GPL(cmf_read);
1304 EXPORT_SYMBOL_GPL(cmf_readall);