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v3.1
   1/*
   2 * linux/drivers/s390/cio/cmf.c
   3 *
   4 * Linux on zSeries Channel Measurement Facility support
   5 *
   6 * Copyright 2000,2006 IBM Corporation
   7 *
   8 * Authors: Arnd Bergmann <arndb@de.ibm.com>
   9 *	    Cornelia Huck <cornelia.huck@de.ibm.com>
  10 *
  11 * original idea from Natarajan Krishnaswami <nkrishna@us.ibm.com>
  12 *
  13 * This program is free software; you can redistribute it and/or modify
  14 * it under the terms of the GNU General Public License as published by
  15 * the Free Software Foundation; either version 2, or (at your option)
  16 * any later version.
  17 *
  18 * This program is distributed in the hope that it will be useful,
  19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 * GNU General Public License for more details.
  22 *
  23 * You should have received a copy of the GNU General Public License
  24 * along with this program; if not, write to the Free Software
  25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26 */
  27
  28#define KMSG_COMPONENT "cio"
  29#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  30
  31#include <linux/bootmem.h>
  32#include <linux/device.h>
  33#include <linux/init.h>
  34#include <linux/list.h>
  35#include <linux/module.h>
  36#include <linux/moduleparam.h>
  37#include <linux/slab.h>
  38#include <linux/timex.h>	/* get_clock() */
  39
  40#include <asm/ccwdev.h>
  41#include <asm/cio.h>
  42#include <asm/cmb.h>
  43#include <asm/div64.h>
  44
  45#include "cio.h"
  46#include "css.h"
  47#include "device.h"
  48#include "ioasm.h"
  49#include "chsc.h"
  50
  51/*
  52 * parameter to enable cmf during boot, possible uses are:
  53 *  "s390cmf" -- enable cmf and allocate 2 MB of ram so measuring can be
  54 *               used on any subchannel
  55 *  "s390cmf=<num>" -- enable cmf and allocate enough memory to measure
  56 *                     <num> subchannel, where <num> is an integer
  57 *                     between 1 and 65535, default is 1024
  58 */
  59#define ARGSTRING "s390cmf"
  60
  61/* indices for READCMB */
  62enum cmb_index {
  63 /* basic and exended format: */
  64	cmb_ssch_rsch_count,
  65	cmb_sample_count,
  66	cmb_device_connect_time,
  67	cmb_function_pending_time,
  68	cmb_device_disconnect_time,
  69	cmb_control_unit_queuing_time,
  70	cmb_device_active_only_time,
  71 /* extended format only: */
  72	cmb_device_busy_time,
  73	cmb_initial_command_response_time,
  74};
  75
  76/**
  77 * enum cmb_format - types of supported measurement block formats
  78 *
  79 * @CMF_BASIC:      traditional channel measurement blocks supported
  80 *		    by all machines that we run on
  81 * @CMF_EXTENDED:   improved format that was introduced with the z990
  82 *		    machine
  83 * @CMF_AUTODETECT: default: use extended format when running on a machine
  84 *		    supporting extended format, otherwise fall back to
  85 *		    basic format
  86 */
  87enum cmb_format {
  88	CMF_BASIC,
  89	CMF_EXTENDED,
  90	CMF_AUTODETECT = -1,
  91};
  92
  93/*
  94 * format - actual format for all measurement blocks
  95 *
  96 * The format module parameter can be set to a value of 0 (zero)
  97 * or 1, indicating basic or extended format as described for
  98 * enum cmb_format.
  99 */
 100static int format = CMF_AUTODETECT;
 101module_param(format, bool, 0444);
 102
 103/**
 104 * struct cmb_operations - functions to use depending on cmb_format
 105 *
 106 * Most of these functions operate on a struct ccw_device. There is only
 107 * one instance of struct cmb_operations because the format of the measurement
 108 * data is guaranteed to be the same for every ccw_device.
 109 *
 110 * @alloc:	allocate memory for a channel measurement block,
 111 *		either with the help of a special pool or with kmalloc
 112 * @free:	free memory allocated with @alloc
 113 * @set:	enable or disable measurement
 114 * @read:	read a measurement entry at an index
 115 * @readall:	read a measurement block in a common format
 116 * @reset:	clear the data in the associated measurement block and
 117 *		reset its time stamp
 118 * @align:	align an allocated block so that the hardware can use it
 119 */
 120struct cmb_operations {
 121	int  (*alloc)  (struct ccw_device *);
 122	void (*free)   (struct ccw_device *);
 123	int  (*set)    (struct ccw_device *, u32);
 124	u64  (*read)   (struct ccw_device *, int);
 125	int  (*readall)(struct ccw_device *, struct cmbdata *);
 126	void (*reset)  (struct ccw_device *);
 127	void *(*align) (void *);
 128/* private: */
 129	struct attribute_group *attr_group;
 130};
 131static struct cmb_operations *cmbops;
 132
 133struct cmb_data {
 134	void *hw_block;   /* Pointer to block updated by hardware */
 135	void *last_block; /* Last changed block copied from hardware block */
 136	int size;	  /* Size of hw_block and last_block */
 137	unsigned long long last_update;  /* when last_block was updated */
 138};
 139
 140/*
 141 * Our user interface is designed in terms of nanoseconds,
 142 * while the hardware measures total times in its own
 143 * unit.
 144 */
 145static inline u64 time_to_nsec(u32 value)
 146{
 147	return ((u64)value) * 128000ull;
 148}
 149
 150/*
 151 * Users are usually interested in average times,
 152 * not accumulated time.
 153 * This also helps us with atomicity problems
 154 * when reading sinlge values.
 155 */
 156static inline u64 time_to_avg_nsec(u32 value, u32 count)
 157{
 158	u64 ret;
 159
 160	/* no samples yet, avoid division by 0 */
 161	if (count == 0)
 162		return 0;
 163
 164	/* value comes in units of 128 µsec */
 165	ret = time_to_nsec(value);
 166	do_div(ret, count);
 167
 168	return ret;
 169}
 170
 171/*
 172 * Activate or deactivate the channel monitor. When area is NULL,
 173 * the monitor is deactivated. The channel monitor needs to
 174 * be active in order to measure subchannels, which also need
 175 * to be enabled.
 176 */
 177static inline void cmf_activate(void *area, unsigned int onoff)
 178{
 179	register void * __gpr2 asm("2");
 180	register long __gpr1 asm("1");
 181
 182	__gpr2 = area;
 183	__gpr1 = onoff ? 2 : 0;
 184	/* activate channel measurement */
 185	asm("schm" : : "d" (__gpr2), "d" (__gpr1) );
 186}
 187
 188static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
 189		     unsigned long address)
 190{
 191	struct subchannel *sch;
 192
 193	sch = to_subchannel(cdev->dev.parent);
 194
 195	sch->config.mme = mme;
 196	sch->config.mbfc = mbfc;
 197	/* address can be either a block address or a block index */
 198	if (mbfc)
 199		sch->config.mba = address;
 200	else
 201		sch->config.mbi = address;
 202
 203	return cio_commit_config(sch);
 204}
 205
 206struct set_schib_struct {
 207	u32 mme;
 208	int mbfc;
 209	unsigned long address;
 210	wait_queue_head_t wait;
 211	int ret;
 212	struct kref kref;
 213};
 214
 215static void cmf_set_schib_release(struct kref *kref)
 216{
 217	struct set_schib_struct *set_data;
 218
 219	set_data = container_of(kref, struct set_schib_struct, kref);
 220	kfree(set_data);
 221}
 222
 223#define CMF_PENDING 1
 224
 225static int set_schib_wait(struct ccw_device *cdev, u32 mme,
 226				int mbfc, unsigned long address)
 227{
 228	struct set_schib_struct *set_data;
 229	int ret;
 230
 231	spin_lock_irq(cdev->ccwlock);
 232	if (!cdev->private->cmb) {
 233		ret = -ENODEV;
 234		goto out;
 235	}
 236	set_data = kzalloc(sizeof(struct set_schib_struct), GFP_ATOMIC);
 237	if (!set_data) {
 238		ret = -ENOMEM;
 239		goto out;
 240	}
 241	init_waitqueue_head(&set_data->wait);
 242	kref_init(&set_data->kref);
 243	set_data->mme = mme;
 244	set_data->mbfc = mbfc;
 245	set_data->address = address;
 246
 247	ret = set_schib(cdev, mme, mbfc, address);
 248	if (ret != -EBUSY)
 249		goto out_put;
 250
 251	if (cdev->private->state != DEV_STATE_ONLINE) {
 252		/* if the device is not online, don't even try again */
 253		ret = -EBUSY;
 254		goto out_put;
 255	}
 256
 257	cdev->private->state = DEV_STATE_CMFCHANGE;
 258	set_data->ret = CMF_PENDING;
 259	cdev->private->cmb_wait = set_data;
 260
 261	spin_unlock_irq(cdev->ccwlock);
 262	if (wait_event_interruptible(set_data->wait,
 263				     set_data->ret != CMF_PENDING)) {
 264		spin_lock_irq(cdev->ccwlock);
 265		if (set_data->ret == CMF_PENDING) {
 266			set_data->ret = -ERESTARTSYS;
 267			if (cdev->private->state == DEV_STATE_CMFCHANGE)
 268				cdev->private->state = DEV_STATE_ONLINE;
 269		}
 270		spin_unlock_irq(cdev->ccwlock);
 271	}
 272	spin_lock_irq(cdev->ccwlock);
 273	cdev->private->cmb_wait = NULL;
 274	ret = set_data->ret;
 275out_put:
 276	kref_put(&set_data->kref, cmf_set_schib_release);
 277out:
 278	spin_unlock_irq(cdev->ccwlock);
 279	return ret;
 280}
 281
 282void retry_set_schib(struct ccw_device *cdev)
 283{
 284	struct set_schib_struct *set_data;
 285
 286	set_data = cdev->private->cmb_wait;
 287	if (!set_data) {
 288		WARN_ON(1);
 289		return;
 290	}
 291	kref_get(&set_data->kref);
 292	set_data->ret = set_schib(cdev, set_data->mme, set_data->mbfc,
 293				  set_data->address);
 294	wake_up(&set_data->wait);
 295	kref_put(&set_data->kref, cmf_set_schib_release);
 296}
 297
 298static int cmf_copy_block(struct ccw_device *cdev)
 299{
 300	struct subchannel *sch;
 301	void *reference_buf;
 302	void *hw_block;
 303	struct cmb_data *cmb_data;
 304
 305	sch = to_subchannel(cdev->dev.parent);
 306
 307	if (cio_update_schib(sch))
 308		return -ENODEV;
 309
 310	if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
 311		/* Don't copy if a start function is in progress. */
 312		if ((!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_SUSPENDED)) &&
 313		    (scsw_actl(&sch->schib.scsw) &
 314		     (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) &&
 315		    (!(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_SEC_STATUS)))
 316			return -EBUSY;
 317	}
 318	cmb_data = cdev->private->cmb;
 319	hw_block = cmbops->align(cmb_data->hw_block);
 320	if (!memcmp(cmb_data->last_block, hw_block, cmb_data->size))
 321		/* No need to copy. */
 322		return 0;
 323	reference_buf = kzalloc(cmb_data->size, GFP_ATOMIC);
 324	if (!reference_buf)
 325		return -ENOMEM;
 326	/* Ensure consistency of block copied from hardware. */
 327	do {
 328		memcpy(cmb_data->last_block, hw_block, cmb_data->size);
 329		memcpy(reference_buf, hw_block, cmb_data->size);
 330	} while (memcmp(cmb_data->last_block, reference_buf, cmb_data->size));
 331	cmb_data->last_update = get_clock();
 332	kfree(reference_buf);
 333	return 0;
 334}
 335
 336struct copy_block_struct {
 337	wait_queue_head_t wait;
 338	int ret;
 339	struct kref kref;
 340};
 341
 342static void cmf_copy_block_release(struct kref *kref)
 343{
 344	struct copy_block_struct *copy_block;
 345
 346	copy_block = container_of(kref, struct copy_block_struct, kref);
 347	kfree(copy_block);
 348}
 349
 350static int cmf_cmb_copy_wait(struct ccw_device *cdev)
 351{
 352	struct copy_block_struct *copy_block;
 353	int ret;
 354	unsigned long flags;
 355
 356	spin_lock_irqsave(cdev->ccwlock, flags);
 357	if (!cdev->private->cmb) {
 358		ret = -ENODEV;
 359		goto out;
 360	}
 361	copy_block = kzalloc(sizeof(struct copy_block_struct), GFP_ATOMIC);
 362	if (!copy_block) {
 363		ret = -ENOMEM;
 364		goto out;
 365	}
 366	init_waitqueue_head(&copy_block->wait);
 367	kref_init(&copy_block->kref);
 368
 369	ret = cmf_copy_block(cdev);
 370	if (ret != -EBUSY)
 371		goto out_put;
 372
 373	if (cdev->private->state != DEV_STATE_ONLINE) {
 374		ret = -EBUSY;
 375		goto out_put;
 376	}
 377
 378	cdev->private->state = DEV_STATE_CMFUPDATE;
 379	copy_block->ret = CMF_PENDING;
 380	cdev->private->cmb_wait = copy_block;
 381
 382	spin_unlock_irqrestore(cdev->ccwlock, flags);
 383	if (wait_event_interruptible(copy_block->wait,
 384				     copy_block->ret != CMF_PENDING)) {
 385		spin_lock_irqsave(cdev->ccwlock, flags);
 386		if (copy_block->ret == CMF_PENDING) {
 387			copy_block->ret = -ERESTARTSYS;
 388			if (cdev->private->state == DEV_STATE_CMFUPDATE)
 389				cdev->private->state = DEV_STATE_ONLINE;
 390		}
 391		spin_unlock_irqrestore(cdev->ccwlock, flags);
 392	}
 393	spin_lock_irqsave(cdev->ccwlock, flags);
 394	cdev->private->cmb_wait = NULL;
 395	ret = copy_block->ret;
 396out_put:
 397	kref_put(&copy_block->kref, cmf_copy_block_release);
 398out:
 399	spin_unlock_irqrestore(cdev->ccwlock, flags);
 400	return ret;
 401}
 402
 403void cmf_retry_copy_block(struct ccw_device *cdev)
 404{
 405	struct copy_block_struct *copy_block;
 406
 407	copy_block = cdev->private->cmb_wait;
 408	if (!copy_block) {
 409		WARN_ON(1);
 410		return;
 411	}
 412	kref_get(&copy_block->kref);
 413	copy_block->ret = cmf_copy_block(cdev);
 414	wake_up(&copy_block->wait);
 415	kref_put(&copy_block->kref, cmf_copy_block_release);
 416}
 417
 418static void cmf_generic_reset(struct ccw_device *cdev)
 419{
 420	struct cmb_data *cmb_data;
 421
 422	spin_lock_irq(cdev->ccwlock);
 423	cmb_data = cdev->private->cmb;
 424	if (cmb_data) {
 425		memset(cmb_data->last_block, 0, cmb_data->size);
 426		/*
 427		 * Need to reset hw block as well to make the hardware start
 428		 * from 0 again.
 429		 */
 430		memset(cmbops->align(cmb_data->hw_block), 0, cmb_data->size);
 431		cmb_data->last_update = 0;
 432	}
 433	cdev->private->cmb_start_time = get_clock();
 434	spin_unlock_irq(cdev->ccwlock);
 435}
 436
 437/**
 438 * struct cmb_area - container for global cmb data
 439 *
 440 * @mem:	pointer to CMBs (only in basic measurement mode)
 441 * @list:	contains a linked list of all subchannels
 442 * @num_channels: number of channels to be measured
 443 * @lock:	protect concurrent access to @mem and @list
 444 */
 445struct cmb_area {
 446	struct cmb *mem;
 447	struct list_head list;
 448	int num_channels;
 449	spinlock_t lock;
 450};
 451
 452static struct cmb_area cmb_area = {
 453	.lock = __SPIN_LOCK_UNLOCKED(cmb_area.lock),
 454	.list = LIST_HEAD_INIT(cmb_area.list),
 455	.num_channels  = 1024,
 456};
 457
 458/* ****** old style CMB handling ********/
 459
 460/*
 461 * Basic channel measurement blocks are allocated in one contiguous
 462 * block of memory, which can not be moved as long as any channel
 463 * is active. Therefore, a maximum number of subchannels needs to
 464 * be defined somewhere. This is a module parameter, defaulting to
 465 * a reasonable value of 1024, or 32 kb of memory.
 466 * Current kernels don't allow kmalloc with more than 128kb, so the
 467 * maximum is 4096.
 468 */
 469
 470module_param_named(maxchannels, cmb_area.num_channels, uint, 0444);
 471
 472/**
 473 * struct cmb - basic channel measurement block
 474 * @ssch_rsch_count: number of ssch and rsch
 475 * @sample_count: number of samples
 476 * @device_connect_time: time of device connect
 477 * @function_pending_time: time of function pending
 478 * @device_disconnect_time: time of device disconnect
 479 * @control_unit_queuing_time: time of control unit queuing
 480 * @device_active_only_time: time of device active only
 481 * @reserved: unused in basic measurement mode
 482 *
 483 * The measurement block as used by the hardware. The fields are described
 484 * further in z/Architecture Principles of Operation, chapter 17.
 485 *
 486 * The cmb area made up from these blocks must be a contiguous array and may
 487 * not be reallocated or freed.
 488 * Only one cmb area can be present in the system.
 489 */
 490struct cmb {
 491	u16 ssch_rsch_count;
 492	u16 sample_count;
 493	u32 device_connect_time;
 494	u32 function_pending_time;
 495	u32 device_disconnect_time;
 496	u32 control_unit_queuing_time;
 497	u32 device_active_only_time;
 498	u32 reserved[2];
 499};
 500
 501/*
 502 * Insert a single device into the cmb_area list.
 503 * Called with cmb_area.lock held from alloc_cmb.
 504 */
 505static int alloc_cmb_single(struct ccw_device *cdev,
 506			    struct cmb_data *cmb_data)
 507{
 508	struct cmb *cmb;
 509	struct ccw_device_private *node;
 510	int ret;
 511
 512	spin_lock_irq(cdev->ccwlock);
 513	if (!list_empty(&cdev->private->cmb_list)) {
 514		ret = -EBUSY;
 515		goto out;
 516	}
 517
 518	/*
 519	 * Find first unused cmb in cmb_area.mem.
 520	 * This is a little tricky: cmb_area.list
 521	 * remains sorted by ->cmb->hw_data pointers.
 522	 */
 523	cmb = cmb_area.mem;
 524	list_for_each_entry(node, &cmb_area.list, cmb_list) {
 525		struct cmb_data *data;
 526		data = node->cmb;
 527		if ((struct cmb*)data->hw_block > cmb)
 528			break;
 529		cmb++;
 530	}
 531	if (cmb - cmb_area.mem >= cmb_area.num_channels) {
 532		ret = -ENOMEM;
 533		goto out;
 534	}
 535
 536	/* insert new cmb */
 537	list_add_tail(&cdev->private->cmb_list, &node->cmb_list);
 538	cmb_data->hw_block = cmb;
 539	cdev->private->cmb = cmb_data;
 540	ret = 0;
 541out:
 542	spin_unlock_irq(cdev->ccwlock);
 543	return ret;
 544}
 545
 546static int alloc_cmb(struct ccw_device *cdev)
 547{
 548	int ret;
 549	struct cmb *mem;
 550	ssize_t size;
 551	struct cmb_data *cmb_data;
 552
 553	/* Allocate private cmb_data. */
 554	cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
 555	if (!cmb_data)
 556		return -ENOMEM;
 557
 558	cmb_data->last_block = kzalloc(sizeof(struct cmb), GFP_KERNEL);
 559	if (!cmb_data->last_block) {
 560		kfree(cmb_data);
 561		return -ENOMEM;
 562	}
 563	cmb_data->size = sizeof(struct cmb);
 564	spin_lock(&cmb_area.lock);
 565
 566	if (!cmb_area.mem) {
 567		/* there is no user yet, so we need a new area */
 568		size = sizeof(struct cmb) * cmb_area.num_channels;
 569		WARN_ON(!list_empty(&cmb_area.list));
 570
 571		spin_unlock(&cmb_area.lock);
 572		mem = (void*)__get_free_pages(GFP_KERNEL | GFP_DMA,
 573				 get_order(size));
 574		spin_lock(&cmb_area.lock);
 575
 576		if (cmb_area.mem) {
 577			/* ok, another thread was faster */
 578			free_pages((unsigned long)mem, get_order(size));
 579		} else if (!mem) {
 580			/* no luck */
 581			ret = -ENOMEM;
 582			goto out;
 583		} else {
 584			/* everything ok */
 585			memset(mem, 0, size);
 586			cmb_area.mem = mem;
 587			cmf_activate(cmb_area.mem, 1);
 588		}
 589	}
 590
 591	/* do the actual allocation */
 592	ret = alloc_cmb_single(cdev, cmb_data);
 593out:
 594	spin_unlock(&cmb_area.lock);
 595	if (ret) {
 596		kfree(cmb_data->last_block);
 597		kfree(cmb_data);
 598	}
 599	return ret;
 600}
 601
 602static void free_cmb(struct ccw_device *cdev)
 603{
 604	struct ccw_device_private *priv;
 605	struct cmb_data *cmb_data;
 606
 607	spin_lock(&cmb_area.lock);
 608	spin_lock_irq(cdev->ccwlock);
 609
 610	priv = cdev->private;
 611
 612	if (list_empty(&priv->cmb_list)) {
 613		/* already freed */
 614		goto out;
 615	}
 616
 617	cmb_data = priv->cmb;
 618	priv->cmb = NULL;
 619	if (cmb_data)
 620		kfree(cmb_data->last_block);
 621	kfree(cmb_data);
 622	list_del_init(&priv->cmb_list);
 623
 624	if (list_empty(&cmb_area.list)) {
 625		ssize_t size;
 626		size = sizeof(struct cmb) * cmb_area.num_channels;
 627		cmf_activate(NULL, 0);
 628		free_pages((unsigned long)cmb_area.mem, get_order(size));
 629		cmb_area.mem = NULL;
 630	}
 631out:
 632	spin_unlock_irq(cdev->ccwlock);
 633	spin_unlock(&cmb_area.lock);
 634}
 635
 636static int set_cmb(struct ccw_device *cdev, u32 mme)
 637{
 638	u16 offset;
 639	struct cmb_data *cmb_data;
 640	unsigned long flags;
 641
 642	spin_lock_irqsave(cdev->ccwlock, flags);
 643	if (!cdev->private->cmb) {
 644		spin_unlock_irqrestore(cdev->ccwlock, flags);
 645		return -EINVAL;
 646	}
 647	cmb_data = cdev->private->cmb;
 648	offset = mme ? (struct cmb *)cmb_data->hw_block - cmb_area.mem : 0;
 649	spin_unlock_irqrestore(cdev->ccwlock, flags);
 650
 651	return set_schib_wait(cdev, mme, 0, offset);
 652}
 653
 654static u64 read_cmb(struct ccw_device *cdev, int index)
 655{
 656	struct cmb *cmb;
 657	u32 val;
 658	int ret;
 659	unsigned long flags;
 660
 661	ret = cmf_cmb_copy_wait(cdev);
 662	if (ret < 0)
 663		return 0;
 664
 665	spin_lock_irqsave(cdev->ccwlock, flags);
 666	if (!cdev->private->cmb) {
 667		ret = 0;
 668		goto out;
 669	}
 670	cmb = ((struct cmb_data *)cdev->private->cmb)->last_block;
 671
 672	switch (index) {
 673	case cmb_ssch_rsch_count:
 674		ret = cmb->ssch_rsch_count;
 675		goto out;
 676	case cmb_sample_count:
 677		ret = cmb->sample_count;
 678		goto out;
 679	case cmb_device_connect_time:
 680		val = cmb->device_connect_time;
 681		break;
 682	case cmb_function_pending_time:
 683		val = cmb->function_pending_time;
 684		break;
 685	case cmb_device_disconnect_time:
 686		val = cmb->device_disconnect_time;
 687		break;
 688	case cmb_control_unit_queuing_time:
 689		val = cmb->control_unit_queuing_time;
 690		break;
 691	case cmb_device_active_only_time:
 692		val = cmb->device_active_only_time;
 693		break;
 694	default:
 695		ret = 0;
 696		goto out;
 697	}
 698	ret = time_to_avg_nsec(val, cmb->sample_count);
 699out:
 700	spin_unlock_irqrestore(cdev->ccwlock, flags);
 701	return ret;
 702}
 703
 704static int readall_cmb(struct ccw_device *cdev, struct cmbdata *data)
 705{
 706	struct cmb *cmb;
 707	struct cmb_data *cmb_data;
 708	u64 time;
 709	unsigned long flags;
 710	int ret;
 711
 712	ret = cmf_cmb_copy_wait(cdev);
 713	if (ret < 0)
 714		return ret;
 715	spin_lock_irqsave(cdev->ccwlock, flags);
 716	cmb_data = cdev->private->cmb;
 717	if (!cmb_data) {
 718		ret = -ENODEV;
 719		goto out;
 720	}
 721	if (cmb_data->last_update == 0) {
 722		ret = -EAGAIN;
 723		goto out;
 724	}
 725	cmb = cmb_data->last_block;
 726	time = cmb_data->last_update - cdev->private->cmb_start_time;
 727
 728	memset(data, 0, sizeof(struct cmbdata));
 729
 730	/* we only know values before device_busy_time */
 731	data->size = offsetof(struct cmbdata, device_busy_time);
 732
 733	/* convert to nanoseconds */
 734	data->elapsed_time = (time * 1000) >> 12;
 735
 736	/* copy data to new structure */
 737	data->ssch_rsch_count = cmb->ssch_rsch_count;
 738	data->sample_count = cmb->sample_count;
 739
 740	/* time fields are converted to nanoseconds while copying */
 741	data->device_connect_time = time_to_nsec(cmb->device_connect_time);
 742	data->function_pending_time = time_to_nsec(cmb->function_pending_time);
 743	data->device_disconnect_time =
 744		time_to_nsec(cmb->device_disconnect_time);
 745	data->control_unit_queuing_time
 746		= time_to_nsec(cmb->control_unit_queuing_time);
 747	data->device_active_only_time
 748		= time_to_nsec(cmb->device_active_only_time);
 749	ret = 0;
 750out:
 751	spin_unlock_irqrestore(cdev->ccwlock, flags);
 752	return ret;
 753}
 754
 755static void reset_cmb(struct ccw_device *cdev)
 756{
 757	cmf_generic_reset(cdev);
 758}
 759
 760static void * align_cmb(void *area)
 761{
 762	return area;
 763}
 764
 765static struct attribute_group cmf_attr_group;
 766
 767static struct cmb_operations cmbops_basic = {
 768	.alloc	= alloc_cmb,
 769	.free	= free_cmb,
 770	.set	= set_cmb,
 771	.read	= read_cmb,
 772	.readall    = readall_cmb,
 773	.reset	    = reset_cmb,
 774	.align	    = align_cmb,
 775	.attr_group = &cmf_attr_group,
 776};
 777
 778/* ******** extended cmb handling ********/
 779
 780/**
 781 * struct cmbe - extended channel measurement block
 782 * @ssch_rsch_count: number of ssch and rsch
 783 * @sample_count: number of samples
 784 * @device_connect_time: time of device connect
 785 * @function_pending_time: time of function pending
 786 * @device_disconnect_time: time of device disconnect
 787 * @control_unit_queuing_time: time of control unit queuing
 788 * @device_active_only_time: time of device active only
 789 * @device_busy_time: time of device busy
 790 * @initial_command_response_time: initial command response time
 791 * @reserved: unused
 792 *
 793 * The measurement block as used by the hardware. May be in any 64 bit physical
 794 * location.
 795 * The fields are described further in z/Architecture Principles of Operation,
 796 * third edition, chapter 17.
 797 */
 798struct cmbe {
 799	u32 ssch_rsch_count;
 800	u32 sample_count;
 801	u32 device_connect_time;
 802	u32 function_pending_time;
 803	u32 device_disconnect_time;
 804	u32 control_unit_queuing_time;
 805	u32 device_active_only_time;
 806	u32 device_busy_time;
 807	u32 initial_command_response_time;
 808	u32 reserved[7];
 809};
 810
 811/*
 812 * kmalloc only guarantees 8 byte alignment, but we need cmbe
 813 * pointers to be naturally aligned. Make sure to allocate
 814 * enough space for two cmbes.
 815 */
 816static inline struct cmbe *cmbe_align(struct cmbe *c)
 817{
 818	unsigned long addr;
 819	addr = ((unsigned long)c + sizeof (struct cmbe) - sizeof(long)) &
 820				 ~(sizeof (struct cmbe) - sizeof(long));
 821	return (struct cmbe*)addr;
 822}
 823
 824static int alloc_cmbe(struct ccw_device *cdev)
 825{
 826	struct cmbe *cmbe;
 827	struct cmb_data *cmb_data;
 828	int ret;
 829
 830	cmbe = kzalloc (sizeof (*cmbe) * 2, GFP_KERNEL);
 831	if (!cmbe)
 832		return -ENOMEM;
 833	cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
 834	if (!cmb_data) {
 835		ret = -ENOMEM;
 836		goto out_free;
 837	}
 838	cmb_data->last_block = kzalloc(sizeof(struct cmbe), GFP_KERNEL);
 839	if (!cmb_data->last_block) {
 840		ret = -ENOMEM;
 841		goto out_free;
 842	}
 843	cmb_data->size = sizeof(struct cmbe);
 844	spin_lock_irq(cdev->ccwlock);
 845	if (cdev->private->cmb) {
 846		spin_unlock_irq(cdev->ccwlock);
 847		ret = -EBUSY;
 848		goto out_free;
 849	}
 850	cmb_data->hw_block = cmbe;
 851	cdev->private->cmb = cmb_data;
 852	spin_unlock_irq(cdev->ccwlock);
 853
 854	/* activate global measurement if this is the first channel */
 855	spin_lock(&cmb_area.lock);
 856	if (list_empty(&cmb_area.list))
 857		cmf_activate(NULL, 1);
 858	list_add_tail(&cdev->private->cmb_list, &cmb_area.list);
 859	spin_unlock(&cmb_area.lock);
 860
 861	return 0;
 862out_free:
 863	if (cmb_data)
 864		kfree(cmb_data->last_block);
 865	kfree(cmb_data);
 866	kfree(cmbe);
 867	return ret;
 868}
 869
 870static void free_cmbe(struct ccw_device *cdev)
 871{
 872	struct cmb_data *cmb_data;
 873
 874	spin_lock_irq(cdev->ccwlock);
 875	cmb_data = cdev->private->cmb;
 876	cdev->private->cmb = NULL;
 877	if (cmb_data)
 878		kfree(cmb_data->last_block);
 879	kfree(cmb_data);
 880	spin_unlock_irq(cdev->ccwlock);
 881
 882	/* deactivate global measurement if this is the last channel */
 883	spin_lock(&cmb_area.lock);
 884	list_del_init(&cdev->private->cmb_list);
 885	if (list_empty(&cmb_area.list))
 886		cmf_activate(NULL, 0);
 887	spin_unlock(&cmb_area.lock);
 888}
 889
 890static int set_cmbe(struct ccw_device *cdev, u32 mme)
 891{
 892	unsigned long mba;
 893	struct cmb_data *cmb_data;
 894	unsigned long flags;
 895
 896	spin_lock_irqsave(cdev->ccwlock, flags);
 897	if (!cdev->private->cmb) {
 898		spin_unlock_irqrestore(cdev->ccwlock, flags);
 899		return -EINVAL;
 900	}
 901	cmb_data = cdev->private->cmb;
 902	mba = mme ? (unsigned long) cmbe_align(cmb_data->hw_block) : 0;
 903	spin_unlock_irqrestore(cdev->ccwlock, flags);
 904
 905	return set_schib_wait(cdev, mme, 1, mba);
 906}
 907
 908
 909static u64 read_cmbe(struct ccw_device *cdev, int index)
 910{
 911	struct cmbe *cmb;
 912	struct cmb_data *cmb_data;
 913	u32 val;
 914	int ret;
 915	unsigned long flags;
 916
 917	ret = cmf_cmb_copy_wait(cdev);
 918	if (ret < 0)
 919		return 0;
 920
 921	spin_lock_irqsave(cdev->ccwlock, flags);
 922	cmb_data = cdev->private->cmb;
 923	if (!cmb_data) {
 924		ret = 0;
 925		goto out;
 926	}
 927	cmb = cmb_data->last_block;
 928
 929	switch (index) {
 930	case cmb_ssch_rsch_count:
 931		ret = cmb->ssch_rsch_count;
 932		goto out;
 933	case cmb_sample_count:
 934		ret = cmb->sample_count;
 935		goto out;
 936	case cmb_device_connect_time:
 937		val = cmb->device_connect_time;
 938		break;
 939	case cmb_function_pending_time:
 940		val = cmb->function_pending_time;
 941		break;
 942	case cmb_device_disconnect_time:
 943		val = cmb->device_disconnect_time;
 944		break;
 945	case cmb_control_unit_queuing_time:
 946		val = cmb->control_unit_queuing_time;
 947		break;
 948	case cmb_device_active_only_time:
 949		val = cmb->device_active_only_time;
 950		break;
 951	case cmb_device_busy_time:
 952		val = cmb->device_busy_time;
 953		break;
 954	case cmb_initial_command_response_time:
 955		val = cmb->initial_command_response_time;
 956		break;
 957	default:
 958		ret = 0;
 959		goto out;
 960	}
 961	ret = time_to_avg_nsec(val, cmb->sample_count);
 962out:
 963	spin_unlock_irqrestore(cdev->ccwlock, flags);
 964	return ret;
 965}
 966
 967static int readall_cmbe(struct ccw_device *cdev, struct cmbdata *data)
 968{
 969	struct cmbe *cmb;
 970	struct cmb_data *cmb_data;
 971	u64 time;
 972	unsigned long flags;
 973	int ret;
 974
 975	ret = cmf_cmb_copy_wait(cdev);
 976	if (ret < 0)
 977		return ret;
 978	spin_lock_irqsave(cdev->ccwlock, flags);
 979	cmb_data = cdev->private->cmb;
 980	if (!cmb_data) {
 981		ret = -ENODEV;
 982		goto out;
 983	}
 984	if (cmb_data->last_update == 0) {
 985		ret = -EAGAIN;
 986		goto out;
 987	}
 988	time = cmb_data->last_update - cdev->private->cmb_start_time;
 989
 990	memset (data, 0, sizeof(struct cmbdata));
 991
 992	/* we only know values before device_busy_time */
 993	data->size = offsetof(struct cmbdata, device_busy_time);
 994
 995	/* conver to nanoseconds */
 996	data->elapsed_time = (time * 1000) >> 12;
 997
 998	cmb = cmb_data->last_block;
 999	/* copy data to new structure */
1000	data->ssch_rsch_count = cmb->ssch_rsch_count;
1001	data->sample_count = cmb->sample_count;
1002
1003	/* time fields are converted to nanoseconds while copying */
1004	data->device_connect_time = time_to_nsec(cmb->device_connect_time);
1005	data->function_pending_time = time_to_nsec(cmb->function_pending_time);
1006	data->device_disconnect_time =
1007		time_to_nsec(cmb->device_disconnect_time);
1008	data->control_unit_queuing_time
1009		= time_to_nsec(cmb->control_unit_queuing_time);
1010	data->device_active_only_time
1011		= time_to_nsec(cmb->device_active_only_time);
1012	data->device_busy_time = time_to_nsec(cmb->device_busy_time);
1013	data->initial_command_response_time
1014		= time_to_nsec(cmb->initial_command_response_time);
1015
1016	ret = 0;
1017out:
1018	spin_unlock_irqrestore(cdev->ccwlock, flags);
1019	return ret;
1020}
1021
1022static void reset_cmbe(struct ccw_device *cdev)
1023{
1024	cmf_generic_reset(cdev);
1025}
1026
1027static void * align_cmbe(void *area)
1028{
1029	return cmbe_align(area);
1030}
1031
1032static struct attribute_group cmf_attr_group_ext;
1033
1034static struct cmb_operations cmbops_extended = {
1035	.alloc	    = alloc_cmbe,
1036	.free	    = free_cmbe,
1037	.set	    = set_cmbe,
1038	.read	    = read_cmbe,
1039	.readall    = readall_cmbe,
1040	.reset	    = reset_cmbe,
1041	.align	    = align_cmbe,
1042	.attr_group = &cmf_attr_group_ext,
1043};
1044
1045static ssize_t cmb_show_attr(struct device *dev, char *buf, enum cmb_index idx)
1046{
1047	return sprintf(buf, "%lld\n",
1048		(unsigned long long) cmf_read(to_ccwdev(dev), idx));
1049}
1050
1051static ssize_t cmb_show_avg_sample_interval(struct device *dev,
1052					    struct device_attribute *attr,
1053					    char *buf)
1054{
1055	struct ccw_device *cdev;
1056	long interval;
1057	unsigned long count;
1058	struct cmb_data *cmb_data;
1059
1060	cdev = to_ccwdev(dev);
1061	count = cmf_read(cdev, cmb_sample_count);
1062	spin_lock_irq(cdev->ccwlock);
1063	cmb_data = cdev->private->cmb;
1064	if (count) {
1065		interval = cmb_data->last_update -
1066			cdev->private->cmb_start_time;
1067		interval = (interval * 1000) >> 12;
1068		interval /= count;
1069	} else
1070		interval = -1;
1071	spin_unlock_irq(cdev->ccwlock);
1072	return sprintf(buf, "%ld\n", interval);
1073}
1074
1075static ssize_t cmb_show_avg_utilization(struct device *dev,
1076					struct device_attribute *attr,
1077					char *buf)
1078{
1079	struct cmbdata data;
1080	u64 utilization;
1081	unsigned long t, u;
1082	int ret;
1083
1084	ret = cmf_readall(to_ccwdev(dev), &data);
1085	if (ret == -EAGAIN || ret == -ENODEV)
1086		/* No data (yet/currently) available to use for calculation. */
1087		return sprintf(buf, "n/a\n");
1088	else if (ret)
1089		return ret;
1090
1091	utilization = data.device_connect_time +
1092		      data.function_pending_time +
1093		      data.device_disconnect_time;
1094
1095	/* shift to avoid long long division */
1096	while (-1ul < (data.elapsed_time | utilization)) {
1097		utilization >>= 8;
1098		data.elapsed_time >>= 8;
1099	}
1100
1101	/* calculate value in 0.1 percent units */
1102	t = (unsigned long) data.elapsed_time / 1000;
1103	u = (unsigned long) utilization / t;
1104
1105	return sprintf(buf, "%02ld.%01ld%%\n", u/ 10, u - (u/ 10) * 10);
1106}
1107
1108#define cmf_attr(name) \
1109static ssize_t show_##name(struct device *dev, \
1110			   struct device_attribute *attr, char *buf)	\
1111{ return cmb_show_attr((dev), buf, cmb_##name); } \
1112static DEVICE_ATTR(name, 0444, show_##name, NULL);
1113
1114#define cmf_attr_avg(name) \
1115static ssize_t show_avg_##name(struct device *dev, \
1116			       struct device_attribute *attr, char *buf) \
1117{ return cmb_show_attr((dev), buf, cmb_##name); } \
1118static DEVICE_ATTR(avg_##name, 0444, show_avg_##name, NULL);
1119
1120cmf_attr(ssch_rsch_count);
1121cmf_attr(sample_count);
1122cmf_attr_avg(device_connect_time);
1123cmf_attr_avg(function_pending_time);
1124cmf_attr_avg(device_disconnect_time);
1125cmf_attr_avg(control_unit_queuing_time);
1126cmf_attr_avg(device_active_only_time);
1127cmf_attr_avg(device_busy_time);
1128cmf_attr_avg(initial_command_response_time);
1129
1130static DEVICE_ATTR(avg_sample_interval, 0444, cmb_show_avg_sample_interval,
1131		   NULL);
1132static DEVICE_ATTR(avg_utilization, 0444, cmb_show_avg_utilization, NULL);
1133
1134static struct attribute *cmf_attributes[] = {
1135	&dev_attr_avg_sample_interval.attr,
1136	&dev_attr_avg_utilization.attr,
1137	&dev_attr_ssch_rsch_count.attr,
1138	&dev_attr_sample_count.attr,
1139	&dev_attr_avg_device_connect_time.attr,
1140	&dev_attr_avg_function_pending_time.attr,
1141	&dev_attr_avg_device_disconnect_time.attr,
1142	&dev_attr_avg_control_unit_queuing_time.attr,
1143	&dev_attr_avg_device_active_only_time.attr,
1144	NULL,
1145};
1146
1147static struct attribute_group cmf_attr_group = {
1148	.name  = "cmf",
1149	.attrs = cmf_attributes,
1150};
1151
1152static struct attribute *cmf_attributes_ext[] = {
1153	&dev_attr_avg_sample_interval.attr,
1154	&dev_attr_avg_utilization.attr,
1155	&dev_attr_ssch_rsch_count.attr,
1156	&dev_attr_sample_count.attr,
1157	&dev_attr_avg_device_connect_time.attr,
1158	&dev_attr_avg_function_pending_time.attr,
1159	&dev_attr_avg_device_disconnect_time.attr,
1160	&dev_attr_avg_control_unit_queuing_time.attr,
1161	&dev_attr_avg_device_active_only_time.attr,
1162	&dev_attr_avg_device_busy_time.attr,
1163	&dev_attr_avg_initial_command_response_time.attr,
1164	NULL,
1165};
1166
1167static struct attribute_group cmf_attr_group_ext = {
1168	.name  = "cmf",
1169	.attrs = cmf_attributes_ext,
1170};
1171
1172static ssize_t cmb_enable_show(struct device *dev,
1173			       struct device_attribute *attr,
1174			       char *buf)
1175{
1176	return sprintf(buf, "%d\n", to_ccwdev(dev)->private->cmb ? 1 : 0);
1177}
1178
1179static ssize_t cmb_enable_store(struct device *dev,
1180				struct device_attribute *attr, const char *buf,
1181				size_t c)
1182{
1183	struct ccw_device *cdev;
1184	int ret;
1185	unsigned long val;
1186
1187	ret = strict_strtoul(buf, 16, &val);
1188	if (ret)
1189		return ret;
1190
1191	cdev = to_ccwdev(dev);
1192
1193	switch (val) {
1194	case 0:
1195		ret = disable_cmf(cdev);
1196		break;
1197	case 1:
1198		ret = enable_cmf(cdev);
1199		break;
1200	}
1201
1202	return c;
1203}
1204
1205DEVICE_ATTR(cmb_enable, 0644, cmb_enable_show, cmb_enable_store);
1206
1207int ccw_set_cmf(struct ccw_device *cdev, int enable)
1208{
1209	return cmbops->set(cdev, enable ? 2 : 0);
1210}
1211
1212/**
1213 * enable_cmf() - switch on the channel measurement for a specific device
1214 *  @cdev:	The ccw device to be enabled
1215 *
1216 *  Returns %0 for success or a negative error value.
1217 *
1218 *  Context:
1219 *    non-atomic
1220 */
1221int enable_cmf(struct ccw_device *cdev)
1222{
1223	int ret;
1224
1225	ret = cmbops->alloc(cdev);
1226	cmbops->reset(cdev);
1227	if (ret)
1228		return ret;
1229	ret = cmbops->set(cdev, 2);
1230	if (ret) {
1231		cmbops->free(cdev);
1232		return ret;
1233	}
1234	ret = sysfs_create_group(&cdev->dev.kobj, cmbops->attr_group);
1235	if (!ret)
1236		return 0;
1237	cmbops->set(cdev, 0);  //FIXME: this can fail
1238	cmbops->free(cdev);
1239	return ret;
1240}
1241
1242/**
1243 * disable_cmf() - switch off the channel measurement for a specific device
1244 *  @cdev:	The ccw device to be disabled
1245 *
1246 *  Returns %0 for success or a negative error value.
1247 *
1248 *  Context:
1249 *    non-atomic
1250 */
1251int disable_cmf(struct ccw_device *cdev)
1252{
1253	int ret;
1254
1255	ret = cmbops->set(cdev, 0);
1256	if (ret)
1257		return ret;
1258	cmbops->free(cdev);
1259	sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
1260	return ret;
1261}
1262
1263/**
1264 * cmf_read() - read one value from the current channel measurement block
1265 * @cdev:	the channel to be read
1266 * @index:	the index of the value to be read
1267 *
1268 * Returns the value read or %0 if the value cannot be read.
1269 *
1270 *  Context:
1271 *    any
1272 */
1273u64 cmf_read(struct ccw_device *cdev, int index)
1274{
1275	return cmbops->read(cdev, index);
1276}
1277
1278/**
1279 * cmf_readall() - read the current channel measurement block
1280 * @cdev:	the channel to be read
1281 * @data:	a pointer to a data block that will be filled
1282 *
1283 * Returns %0 on success, a negative error value otherwise.
1284 *
1285 *  Context:
1286 *    any
1287 */
1288int cmf_readall(struct ccw_device *cdev, struct cmbdata *data)
1289{
1290	return cmbops->readall(cdev, data);
1291}
1292
1293/* Reenable cmf when a disconnected device becomes available again. */
1294int cmf_reenable(struct ccw_device *cdev)
1295{
1296	cmbops->reset(cdev);
1297	return cmbops->set(cdev, 2);
1298}
1299
1300static int __init init_cmf(void)
1301{
1302	char *format_string;
1303	char *detect_string = "parameter";
1304
1305	/*
1306	 * If the user did not give a parameter, see if we are running on a
1307	 * machine supporting extended measurement blocks, otherwise fall back
1308	 * to basic mode.
1309	 */
1310	if (format == CMF_AUTODETECT) {
1311		if (!css_general_characteristics.ext_mb) {
1312			format = CMF_BASIC;
1313		} else {
1314			format = CMF_EXTENDED;
1315		}
1316		detect_string = "autodetected";
1317	} else {
1318		detect_string = "parameter";
1319	}
1320
1321	switch (format) {
1322	case CMF_BASIC:
1323		format_string = "basic";
1324		cmbops = &cmbops_basic;
1325		break;
1326	case CMF_EXTENDED:
1327		format_string = "extended";
1328		cmbops = &cmbops_extended;
1329		break;
1330	default:
1331		return 1;
1332	}
1333	pr_info("Channel measurement facility initialized using format "
1334		"%s (mode %s)\n", format_string, detect_string);
1335	return 0;
1336}
1337
1338module_init(init_cmf);
1339
1340
1341MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
1342MODULE_LICENSE("GPL");
1343MODULE_DESCRIPTION("channel measurement facility base driver\n"
1344		   "Copyright 2003 IBM Corporation\n");
1345
1346EXPORT_SYMBOL_GPL(enable_cmf);
1347EXPORT_SYMBOL_GPL(disable_cmf);
1348EXPORT_SYMBOL_GPL(cmf_read);
1349EXPORT_SYMBOL_GPL(cmf_readall);
v3.15
   1/*
 
 
   2 * Linux on zSeries Channel Measurement Facility support
   3 *
   4 * Copyright IBM Corp. 2000, 2006
   5 *
   6 * Authors: Arnd Bergmann <arndb@de.ibm.com>
   7 *	    Cornelia Huck <cornelia.huck@de.ibm.com>
   8 *
   9 * original idea from Natarajan Krishnaswami <nkrishna@us.ibm.com>
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2, or (at your option)
  14 * any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26#define KMSG_COMPONENT "cio"
  27#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  28
  29#include <linux/bootmem.h>
  30#include <linux/device.h>
  31#include <linux/init.h>
  32#include <linux/list.h>
  33#include <linux/module.h>
  34#include <linux/moduleparam.h>
  35#include <linux/slab.h>
  36#include <linux/timex.h>	/* get_tod_clock() */
  37
  38#include <asm/ccwdev.h>
  39#include <asm/cio.h>
  40#include <asm/cmb.h>
  41#include <asm/div64.h>
  42
  43#include "cio.h"
  44#include "css.h"
  45#include "device.h"
  46#include "ioasm.h"
  47#include "chsc.h"
  48
  49/*
  50 * parameter to enable cmf during boot, possible uses are:
  51 *  "s390cmf" -- enable cmf and allocate 2 MB of ram so measuring can be
  52 *               used on any subchannel
  53 *  "s390cmf=<num>" -- enable cmf and allocate enough memory to measure
  54 *                     <num> subchannel, where <num> is an integer
  55 *                     between 1 and 65535, default is 1024
  56 */
  57#define ARGSTRING "s390cmf"
  58
  59/* indices for READCMB */
  60enum cmb_index {
  61 /* basic and exended format: */
  62	cmb_ssch_rsch_count,
  63	cmb_sample_count,
  64	cmb_device_connect_time,
  65	cmb_function_pending_time,
  66	cmb_device_disconnect_time,
  67	cmb_control_unit_queuing_time,
  68	cmb_device_active_only_time,
  69 /* extended format only: */
  70	cmb_device_busy_time,
  71	cmb_initial_command_response_time,
  72};
  73
  74/**
  75 * enum cmb_format - types of supported measurement block formats
  76 *
  77 * @CMF_BASIC:      traditional channel measurement blocks supported
  78 *		    by all machines that we run on
  79 * @CMF_EXTENDED:   improved format that was introduced with the z990
  80 *		    machine
  81 * @CMF_AUTODETECT: default: use extended format when running on a machine
  82 *		    supporting extended format, otherwise fall back to
  83 *		    basic format
  84 */
  85enum cmb_format {
  86	CMF_BASIC,
  87	CMF_EXTENDED,
  88	CMF_AUTODETECT = -1,
  89};
  90
  91/*
  92 * format - actual format for all measurement blocks
  93 *
  94 * The format module parameter can be set to a value of 0 (zero)
  95 * or 1, indicating basic or extended format as described for
  96 * enum cmb_format.
  97 */
  98static int format = CMF_AUTODETECT;
  99module_param(format, bint, 0444);
 100
 101/**
 102 * struct cmb_operations - functions to use depending on cmb_format
 103 *
 104 * Most of these functions operate on a struct ccw_device. There is only
 105 * one instance of struct cmb_operations because the format of the measurement
 106 * data is guaranteed to be the same for every ccw_device.
 107 *
 108 * @alloc:	allocate memory for a channel measurement block,
 109 *		either with the help of a special pool or with kmalloc
 110 * @free:	free memory allocated with @alloc
 111 * @set:	enable or disable measurement
 112 * @read:	read a measurement entry at an index
 113 * @readall:	read a measurement block in a common format
 114 * @reset:	clear the data in the associated measurement block and
 115 *		reset its time stamp
 116 * @align:	align an allocated block so that the hardware can use it
 117 */
 118struct cmb_operations {
 119	int  (*alloc)  (struct ccw_device *);
 120	void (*free)   (struct ccw_device *);
 121	int  (*set)    (struct ccw_device *, u32);
 122	u64  (*read)   (struct ccw_device *, int);
 123	int  (*readall)(struct ccw_device *, struct cmbdata *);
 124	void (*reset)  (struct ccw_device *);
 125	void *(*align) (void *);
 126/* private: */
 127	struct attribute_group *attr_group;
 128};
 129static struct cmb_operations *cmbops;
 130
 131struct cmb_data {
 132	void *hw_block;   /* Pointer to block updated by hardware */
 133	void *last_block; /* Last changed block copied from hardware block */
 134	int size;	  /* Size of hw_block and last_block */
 135	unsigned long long last_update;  /* when last_block was updated */
 136};
 137
 138/*
 139 * Our user interface is designed in terms of nanoseconds,
 140 * while the hardware measures total times in its own
 141 * unit.
 142 */
 143static inline u64 time_to_nsec(u32 value)
 144{
 145	return ((u64)value) * 128000ull;
 146}
 147
 148/*
 149 * Users are usually interested in average times,
 150 * not accumulated time.
 151 * This also helps us with atomicity problems
 152 * when reading sinlge values.
 153 */
 154static inline u64 time_to_avg_nsec(u32 value, u32 count)
 155{
 156	u64 ret;
 157
 158	/* no samples yet, avoid division by 0 */
 159	if (count == 0)
 160		return 0;
 161
 162	/* value comes in units of 128 µsec */
 163	ret = time_to_nsec(value);
 164	do_div(ret, count);
 165
 166	return ret;
 167}
 168
 169/*
 170 * Activate or deactivate the channel monitor. When area is NULL,
 171 * the monitor is deactivated. The channel monitor needs to
 172 * be active in order to measure subchannels, which also need
 173 * to be enabled.
 174 */
 175static inline void cmf_activate(void *area, unsigned int onoff)
 176{
 177	register void * __gpr2 asm("2");
 178	register long __gpr1 asm("1");
 179
 180	__gpr2 = area;
 181	__gpr1 = onoff ? 2 : 0;
 182	/* activate channel measurement */
 183	asm("schm" : : "d" (__gpr2), "d" (__gpr1) );
 184}
 185
 186static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
 187		     unsigned long address)
 188{
 189	struct subchannel *sch;
 190
 191	sch = to_subchannel(cdev->dev.parent);
 192
 193	sch->config.mme = mme;
 194	sch->config.mbfc = mbfc;
 195	/* address can be either a block address or a block index */
 196	if (mbfc)
 197		sch->config.mba = address;
 198	else
 199		sch->config.mbi = address;
 200
 201	return cio_commit_config(sch);
 202}
 203
 204struct set_schib_struct {
 205	u32 mme;
 206	int mbfc;
 207	unsigned long address;
 208	wait_queue_head_t wait;
 209	int ret;
 210	struct kref kref;
 211};
 212
 213static void cmf_set_schib_release(struct kref *kref)
 214{
 215	struct set_schib_struct *set_data;
 216
 217	set_data = container_of(kref, struct set_schib_struct, kref);
 218	kfree(set_data);
 219}
 220
 221#define CMF_PENDING 1
 222
 223static int set_schib_wait(struct ccw_device *cdev, u32 mme,
 224				int mbfc, unsigned long address)
 225{
 226	struct set_schib_struct *set_data;
 227	int ret;
 228
 229	spin_lock_irq(cdev->ccwlock);
 230	if (!cdev->private->cmb) {
 231		ret = -ENODEV;
 232		goto out;
 233	}
 234	set_data = kzalloc(sizeof(struct set_schib_struct), GFP_ATOMIC);
 235	if (!set_data) {
 236		ret = -ENOMEM;
 237		goto out;
 238	}
 239	init_waitqueue_head(&set_data->wait);
 240	kref_init(&set_data->kref);
 241	set_data->mme = mme;
 242	set_data->mbfc = mbfc;
 243	set_data->address = address;
 244
 245	ret = set_schib(cdev, mme, mbfc, address);
 246	if (ret != -EBUSY)
 247		goto out_put;
 248
 249	if (cdev->private->state != DEV_STATE_ONLINE) {
 250		/* if the device is not online, don't even try again */
 251		ret = -EBUSY;
 252		goto out_put;
 253	}
 254
 255	cdev->private->state = DEV_STATE_CMFCHANGE;
 256	set_data->ret = CMF_PENDING;
 257	cdev->private->cmb_wait = set_data;
 258
 259	spin_unlock_irq(cdev->ccwlock);
 260	if (wait_event_interruptible(set_data->wait,
 261				     set_data->ret != CMF_PENDING)) {
 262		spin_lock_irq(cdev->ccwlock);
 263		if (set_data->ret == CMF_PENDING) {
 264			set_data->ret = -ERESTARTSYS;
 265			if (cdev->private->state == DEV_STATE_CMFCHANGE)
 266				cdev->private->state = DEV_STATE_ONLINE;
 267		}
 268		spin_unlock_irq(cdev->ccwlock);
 269	}
 270	spin_lock_irq(cdev->ccwlock);
 271	cdev->private->cmb_wait = NULL;
 272	ret = set_data->ret;
 273out_put:
 274	kref_put(&set_data->kref, cmf_set_schib_release);
 275out:
 276	spin_unlock_irq(cdev->ccwlock);
 277	return ret;
 278}
 279
 280void retry_set_schib(struct ccw_device *cdev)
 281{
 282	struct set_schib_struct *set_data;
 283
 284	set_data = cdev->private->cmb_wait;
 285	if (!set_data) {
 286		WARN_ON(1);
 287		return;
 288	}
 289	kref_get(&set_data->kref);
 290	set_data->ret = set_schib(cdev, set_data->mme, set_data->mbfc,
 291				  set_data->address);
 292	wake_up(&set_data->wait);
 293	kref_put(&set_data->kref, cmf_set_schib_release);
 294}
 295
 296static int cmf_copy_block(struct ccw_device *cdev)
 297{
 298	struct subchannel *sch;
 299	void *reference_buf;
 300	void *hw_block;
 301	struct cmb_data *cmb_data;
 302
 303	sch = to_subchannel(cdev->dev.parent);
 304
 305	if (cio_update_schib(sch))
 306		return -ENODEV;
 307
 308	if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
 309		/* Don't copy if a start function is in progress. */
 310		if ((!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_SUSPENDED)) &&
 311		    (scsw_actl(&sch->schib.scsw) &
 312		     (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) &&
 313		    (!(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_SEC_STATUS)))
 314			return -EBUSY;
 315	}
 316	cmb_data = cdev->private->cmb;
 317	hw_block = cmbops->align(cmb_data->hw_block);
 318	if (!memcmp(cmb_data->last_block, hw_block, cmb_data->size))
 319		/* No need to copy. */
 320		return 0;
 321	reference_buf = kzalloc(cmb_data->size, GFP_ATOMIC);
 322	if (!reference_buf)
 323		return -ENOMEM;
 324	/* Ensure consistency of block copied from hardware. */
 325	do {
 326		memcpy(cmb_data->last_block, hw_block, cmb_data->size);
 327		memcpy(reference_buf, hw_block, cmb_data->size);
 328	} while (memcmp(cmb_data->last_block, reference_buf, cmb_data->size));
 329	cmb_data->last_update = get_tod_clock();
 330	kfree(reference_buf);
 331	return 0;
 332}
 333
 334struct copy_block_struct {
 335	wait_queue_head_t wait;
 336	int ret;
 337	struct kref kref;
 338};
 339
 340static void cmf_copy_block_release(struct kref *kref)
 341{
 342	struct copy_block_struct *copy_block;
 343
 344	copy_block = container_of(kref, struct copy_block_struct, kref);
 345	kfree(copy_block);
 346}
 347
 348static int cmf_cmb_copy_wait(struct ccw_device *cdev)
 349{
 350	struct copy_block_struct *copy_block;
 351	int ret;
 352	unsigned long flags;
 353
 354	spin_lock_irqsave(cdev->ccwlock, flags);
 355	if (!cdev->private->cmb) {
 356		ret = -ENODEV;
 357		goto out;
 358	}
 359	copy_block = kzalloc(sizeof(struct copy_block_struct), GFP_ATOMIC);
 360	if (!copy_block) {
 361		ret = -ENOMEM;
 362		goto out;
 363	}
 364	init_waitqueue_head(&copy_block->wait);
 365	kref_init(&copy_block->kref);
 366
 367	ret = cmf_copy_block(cdev);
 368	if (ret != -EBUSY)
 369		goto out_put;
 370
 371	if (cdev->private->state != DEV_STATE_ONLINE) {
 372		ret = -EBUSY;
 373		goto out_put;
 374	}
 375
 376	cdev->private->state = DEV_STATE_CMFUPDATE;
 377	copy_block->ret = CMF_PENDING;
 378	cdev->private->cmb_wait = copy_block;
 379
 380	spin_unlock_irqrestore(cdev->ccwlock, flags);
 381	if (wait_event_interruptible(copy_block->wait,
 382				     copy_block->ret != CMF_PENDING)) {
 383		spin_lock_irqsave(cdev->ccwlock, flags);
 384		if (copy_block->ret == CMF_PENDING) {
 385			copy_block->ret = -ERESTARTSYS;
 386			if (cdev->private->state == DEV_STATE_CMFUPDATE)
 387				cdev->private->state = DEV_STATE_ONLINE;
 388		}
 389		spin_unlock_irqrestore(cdev->ccwlock, flags);
 390	}
 391	spin_lock_irqsave(cdev->ccwlock, flags);
 392	cdev->private->cmb_wait = NULL;
 393	ret = copy_block->ret;
 394out_put:
 395	kref_put(&copy_block->kref, cmf_copy_block_release);
 396out:
 397	spin_unlock_irqrestore(cdev->ccwlock, flags);
 398	return ret;
 399}
 400
 401void cmf_retry_copy_block(struct ccw_device *cdev)
 402{
 403	struct copy_block_struct *copy_block;
 404
 405	copy_block = cdev->private->cmb_wait;
 406	if (!copy_block) {
 407		WARN_ON(1);
 408		return;
 409	}
 410	kref_get(&copy_block->kref);
 411	copy_block->ret = cmf_copy_block(cdev);
 412	wake_up(&copy_block->wait);
 413	kref_put(&copy_block->kref, cmf_copy_block_release);
 414}
 415
 416static void cmf_generic_reset(struct ccw_device *cdev)
 417{
 418	struct cmb_data *cmb_data;
 419
 420	spin_lock_irq(cdev->ccwlock);
 421	cmb_data = cdev->private->cmb;
 422	if (cmb_data) {
 423		memset(cmb_data->last_block, 0, cmb_data->size);
 424		/*
 425		 * Need to reset hw block as well to make the hardware start
 426		 * from 0 again.
 427		 */
 428		memset(cmbops->align(cmb_data->hw_block), 0, cmb_data->size);
 429		cmb_data->last_update = 0;
 430	}
 431	cdev->private->cmb_start_time = get_tod_clock();
 432	spin_unlock_irq(cdev->ccwlock);
 433}
 434
 435/**
 436 * struct cmb_area - container for global cmb data
 437 *
 438 * @mem:	pointer to CMBs (only in basic measurement mode)
 439 * @list:	contains a linked list of all subchannels
 440 * @num_channels: number of channels to be measured
 441 * @lock:	protect concurrent access to @mem and @list
 442 */
 443struct cmb_area {
 444	struct cmb *mem;
 445	struct list_head list;
 446	int num_channels;
 447	spinlock_t lock;
 448};
 449
 450static struct cmb_area cmb_area = {
 451	.lock = __SPIN_LOCK_UNLOCKED(cmb_area.lock),
 452	.list = LIST_HEAD_INIT(cmb_area.list),
 453	.num_channels  = 1024,
 454};
 455
 456/* ****** old style CMB handling ********/
 457
 458/*
 459 * Basic channel measurement blocks are allocated in one contiguous
 460 * block of memory, which can not be moved as long as any channel
 461 * is active. Therefore, a maximum number of subchannels needs to
 462 * be defined somewhere. This is a module parameter, defaulting to
 463 * a reasonable value of 1024, or 32 kb of memory.
 464 * Current kernels don't allow kmalloc with more than 128kb, so the
 465 * maximum is 4096.
 466 */
 467
 468module_param_named(maxchannels, cmb_area.num_channels, uint, 0444);
 469
 470/**
 471 * struct cmb - basic channel measurement block
 472 * @ssch_rsch_count: number of ssch and rsch
 473 * @sample_count: number of samples
 474 * @device_connect_time: time of device connect
 475 * @function_pending_time: time of function pending
 476 * @device_disconnect_time: time of device disconnect
 477 * @control_unit_queuing_time: time of control unit queuing
 478 * @device_active_only_time: time of device active only
 479 * @reserved: unused in basic measurement mode
 480 *
 481 * The measurement block as used by the hardware. The fields are described
 482 * further in z/Architecture Principles of Operation, chapter 17.
 483 *
 484 * The cmb area made up from these blocks must be a contiguous array and may
 485 * not be reallocated or freed.
 486 * Only one cmb area can be present in the system.
 487 */
 488struct cmb {
 489	u16 ssch_rsch_count;
 490	u16 sample_count;
 491	u32 device_connect_time;
 492	u32 function_pending_time;
 493	u32 device_disconnect_time;
 494	u32 control_unit_queuing_time;
 495	u32 device_active_only_time;
 496	u32 reserved[2];
 497};
 498
 499/*
 500 * Insert a single device into the cmb_area list.
 501 * Called with cmb_area.lock held from alloc_cmb.
 502 */
 503static int alloc_cmb_single(struct ccw_device *cdev,
 504			    struct cmb_data *cmb_data)
 505{
 506	struct cmb *cmb;
 507	struct ccw_device_private *node;
 508	int ret;
 509
 510	spin_lock_irq(cdev->ccwlock);
 511	if (!list_empty(&cdev->private->cmb_list)) {
 512		ret = -EBUSY;
 513		goto out;
 514	}
 515
 516	/*
 517	 * Find first unused cmb in cmb_area.mem.
 518	 * This is a little tricky: cmb_area.list
 519	 * remains sorted by ->cmb->hw_data pointers.
 520	 */
 521	cmb = cmb_area.mem;
 522	list_for_each_entry(node, &cmb_area.list, cmb_list) {
 523		struct cmb_data *data;
 524		data = node->cmb;
 525		if ((struct cmb*)data->hw_block > cmb)
 526			break;
 527		cmb++;
 528	}
 529	if (cmb - cmb_area.mem >= cmb_area.num_channels) {
 530		ret = -ENOMEM;
 531		goto out;
 532	}
 533
 534	/* insert new cmb */
 535	list_add_tail(&cdev->private->cmb_list, &node->cmb_list);
 536	cmb_data->hw_block = cmb;
 537	cdev->private->cmb = cmb_data;
 538	ret = 0;
 539out:
 540	spin_unlock_irq(cdev->ccwlock);
 541	return ret;
 542}
 543
 544static int alloc_cmb(struct ccw_device *cdev)
 545{
 546	int ret;
 547	struct cmb *mem;
 548	ssize_t size;
 549	struct cmb_data *cmb_data;
 550
 551	/* Allocate private cmb_data. */
 552	cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
 553	if (!cmb_data)
 554		return -ENOMEM;
 555
 556	cmb_data->last_block = kzalloc(sizeof(struct cmb), GFP_KERNEL);
 557	if (!cmb_data->last_block) {
 558		kfree(cmb_data);
 559		return -ENOMEM;
 560	}
 561	cmb_data->size = sizeof(struct cmb);
 562	spin_lock(&cmb_area.lock);
 563
 564	if (!cmb_area.mem) {
 565		/* there is no user yet, so we need a new area */
 566		size = sizeof(struct cmb) * cmb_area.num_channels;
 567		WARN_ON(!list_empty(&cmb_area.list));
 568
 569		spin_unlock(&cmb_area.lock);
 570		mem = (void*)__get_free_pages(GFP_KERNEL | GFP_DMA,
 571				 get_order(size));
 572		spin_lock(&cmb_area.lock);
 573
 574		if (cmb_area.mem) {
 575			/* ok, another thread was faster */
 576			free_pages((unsigned long)mem, get_order(size));
 577		} else if (!mem) {
 578			/* no luck */
 579			ret = -ENOMEM;
 580			goto out;
 581		} else {
 582			/* everything ok */
 583			memset(mem, 0, size);
 584			cmb_area.mem = mem;
 585			cmf_activate(cmb_area.mem, 1);
 586		}
 587	}
 588
 589	/* do the actual allocation */
 590	ret = alloc_cmb_single(cdev, cmb_data);
 591out:
 592	spin_unlock(&cmb_area.lock);
 593	if (ret) {
 594		kfree(cmb_data->last_block);
 595		kfree(cmb_data);
 596	}
 597	return ret;
 598}
 599
 600static void free_cmb(struct ccw_device *cdev)
 601{
 602	struct ccw_device_private *priv;
 603	struct cmb_data *cmb_data;
 604
 605	spin_lock(&cmb_area.lock);
 606	spin_lock_irq(cdev->ccwlock);
 607
 608	priv = cdev->private;
 609
 610	if (list_empty(&priv->cmb_list)) {
 611		/* already freed */
 612		goto out;
 613	}
 614
 615	cmb_data = priv->cmb;
 616	priv->cmb = NULL;
 617	if (cmb_data)
 618		kfree(cmb_data->last_block);
 619	kfree(cmb_data);
 620	list_del_init(&priv->cmb_list);
 621
 622	if (list_empty(&cmb_area.list)) {
 623		ssize_t size;
 624		size = sizeof(struct cmb) * cmb_area.num_channels;
 625		cmf_activate(NULL, 0);
 626		free_pages((unsigned long)cmb_area.mem, get_order(size));
 627		cmb_area.mem = NULL;
 628	}
 629out:
 630	spin_unlock_irq(cdev->ccwlock);
 631	spin_unlock(&cmb_area.lock);
 632}
 633
 634static int set_cmb(struct ccw_device *cdev, u32 mme)
 635{
 636	u16 offset;
 637	struct cmb_data *cmb_data;
 638	unsigned long flags;
 639
 640	spin_lock_irqsave(cdev->ccwlock, flags);
 641	if (!cdev->private->cmb) {
 642		spin_unlock_irqrestore(cdev->ccwlock, flags);
 643		return -EINVAL;
 644	}
 645	cmb_data = cdev->private->cmb;
 646	offset = mme ? (struct cmb *)cmb_data->hw_block - cmb_area.mem : 0;
 647	spin_unlock_irqrestore(cdev->ccwlock, flags);
 648
 649	return set_schib_wait(cdev, mme, 0, offset);
 650}
 651
 652static u64 read_cmb(struct ccw_device *cdev, int index)
 653{
 654	struct cmb *cmb;
 655	u32 val;
 656	int ret;
 657	unsigned long flags;
 658
 659	ret = cmf_cmb_copy_wait(cdev);
 660	if (ret < 0)
 661		return 0;
 662
 663	spin_lock_irqsave(cdev->ccwlock, flags);
 664	if (!cdev->private->cmb) {
 665		ret = 0;
 666		goto out;
 667	}
 668	cmb = ((struct cmb_data *)cdev->private->cmb)->last_block;
 669
 670	switch (index) {
 671	case cmb_ssch_rsch_count:
 672		ret = cmb->ssch_rsch_count;
 673		goto out;
 674	case cmb_sample_count:
 675		ret = cmb->sample_count;
 676		goto out;
 677	case cmb_device_connect_time:
 678		val = cmb->device_connect_time;
 679		break;
 680	case cmb_function_pending_time:
 681		val = cmb->function_pending_time;
 682		break;
 683	case cmb_device_disconnect_time:
 684		val = cmb->device_disconnect_time;
 685		break;
 686	case cmb_control_unit_queuing_time:
 687		val = cmb->control_unit_queuing_time;
 688		break;
 689	case cmb_device_active_only_time:
 690		val = cmb->device_active_only_time;
 691		break;
 692	default:
 693		ret = 0;
 694		goto out;
 695	}
 696	ret = time_to_avg_nsec(val, cmb->sample_count);
 697out:
 698	spin_unlock_irqrestore(cdev->ccwlock, flags);
 699	return ret;
 700}
 701
 702static int readall_cmb(struct ccw_device *cdev, struct cmbdata *data)
 703{
 704	struct cmb *cmb;
 705	struct cmb_data *cmb_data;
 706	u64 time;
 707	unsigned long flags;
 708	int ret;
 709
 710	ret = cmf_cmb_copy_wait(cdev);
 711	if (ret < 0)
 712		return ret;
 713	spin_lock_irqsave(cdev->ccwlock, flags);
 714	cmb_data = cdev->private->cmb;
 715	if (!cmb_data) {
 716		ret = -ENODEV;
 717		goto out;
 718	}
 719	if (cmb_data->last_update == 0) {
 720		ret = -EAGAIN;
 721		goto out;
 722	}
 723	cmb = cmb_data->last_block;
 724	time = cmb_data->last_update - cdev->private->cmb_start_time;
 725
 726	memset(data, 0, sizeof(struct cmbdata));
 727
 728	/* we only know values before device_busy_time */
 729	data->size = offsetof(struct cmbdata, device_busy_time);
 730
 731	/* convert to nanoseconds */
 732	data->elapsed_time = (time * 1000) >> 12;
 733
 734	/* copy data to new structure */
 735	data->ssch_rsch_count = cmb->ssch_rsch_count;
 736	data->sample_count = cmb->sample_count;
 737
 738	/* time fields are converted to nanoseconds while copying */
 739	data->device_connect_time = time_to_nsec(cmb->device_connect_time);
 740	data->function_pending_time = time_to_nsec(cmb->function_pending_time);
 741	data->device_disconnect_time =
 742		time_to_nsec(cmb->device_disconnect_time);
 743	data->control_unit_queuing_time
 744		= time_to_nsec(cmb->control_unit_queuing_time);
 745	data->device_active_only_time
 746		= time_to_nsec(cmb->device_active_only_time);
 747	ret = 0;
 748out:
 749	spin_unlock_irqrestore(cdev->ccwlock, flags);
 750	return ret;
 751}
 752
 753static void reset_cmb(struct ccw_device *cdev)
 754{
 755	cmf_generic_reset(cdev);
 756}
 757
 758static void * align_cmb(void *area)
 759{
 760	return area;
 761}
 762
 763static struct attribute_group cmf_attr_group;
 764
 765static struct cmb_operations cmbops_basic = {
 766	.alloc	= alloc_cmb,
 767	.free	= free_cmb,
 768	.set	= set_cmb,
 769	.read	= read_cmb,
 770	.readall    = readall_cmb,
 771	.reset	    = reset_cmb,
 772	.align	    = align_cmb,
 773	.attr_group = &cmf_attr_group,
 774};
 775
 776/* ******** extended cmb handling ********/
 777
 778/**
 779 * struct cmbe - extended channel measurement block
 780 * @ssch_rsch_count: number of ssch and rsch
 781 * @sample_count: number of samples
 782 * @device_connect_time: time of device connect
 783 * @function_pending_time: time of function pending
 784 * @device_disconnect_time: time of device disconnect
 785 * @control_unit_queuing_time: time of control unit queuing
 786 * @device_active_only_time: time of device active only
 787 * @device_busy_time: time of device busy
 788 * @initial_command_response_time: initial command response time
 789 * @reserved: unused
 790 *
 791 * The measurement block as used by the hardware. May be in any 64 bit physical
 792 * location.
 793 * The fields are described further in z/Architecture Principles of Operation,
 794 * third edition, chapter 17.
 795 */
 796struct cmbe {
 797	u32 ssch_rsch_count;
 798	u32 sample_count;
 799	u32 device_connect_time;
 800	u32 function_pending_time;
 801	u32 device_disconnect_time;
 802	u32 control_unit_queuing_time;
 803	u32 device_active_only_time;
 804	u32 device_busy_time;
 805	u32 initial_command_response_time;
 806	u32 reserved[7];
 807};
 808
 809/*
 810 * kmalloc only guarantees 8 byte alignment, but we need cmbe
 811 * pointers to be naturally aligned. Make sure to allocate
 812 * enough space for two cmbes.
 813 */
 814static inline struct cmbe *cmbe_align(struct cmbe *c)
 815{
 816	unsigned long addr;
 817	addr = ((unsigned long)c + sizeof (struct cmbe) - sizeof(long)) &
 818				 ~(sizeof (struct cmbe) - sizeof(long));
 819	return (struct cmbe*)addr;
 820}
 821
 822static int alloc_cmbe(struct ccw_device *cdev)
 823{
 824	struct cmbe *cmbe;
 825	struct cmb_data *cmb_data;
 826	int ret;
 827
 828	cmbe = kzalloc (sizeof (*cmbe) * 2, GFP_KERNEL);
 829	if (!cmbe)
 830		return -ENOMEM;
 831	cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
 832	if (!cmb_data) {
 833		ret = -ENOMEM;
 834		goto out_free;
 835	}
 836	cmb_data->last_block = kzalloc(sizeof(struct cmbe), GFP_KERNEL);
 837	if (!cmb_data->last_block) {
 838		ret = -ENOMEM;
 839		goto out_free;
 840	}
 841	cmb_data->size = sizeof(struct cmbe);
 842	spin_lock_irq(cdev->ccwlock);
 843	if (cdev->private->cmb) {
 844		spin_unlock_irq(cdev->ccwlock);
 845		ret = -EBUSY;
 846		goto out_free;
 847	}
 848	cmb_data->hw_block = cmbe;
 849	cdev->private->cmb = cmb_data;
 850	spin_unlock_irq(cdev->ccwlock);
 851
 852	/* activate global measurement if this is the first channel */
 853	spin_lock(&cmb_area.lock);
 854	if (list_empty(&cmb_area.list))
 855		cmf_activate(NULL, 1);
 856	list_add_tail(&cdev->private->cmb_list, &cmb_area.list);
 857	spin_unlock(&cmb_area.lock);
 858
 859	return 0;
 860out_free:
 861	if (cmb_data)
 862		kfree(cmb_data->last_block);
 863	kfree(cmb_data);
 864	kfree(cmbe);
 865	return ret;
 866}
 867
 868static void free_cmbe(struct ccw_device *cdev)
 869{
 870	struct cmb_data *cmb_data;
 871
 872	spin_lock_irq(cdev->ccwlock);
 873	cmb_data = cdev->private->cmb;
 874	cdev->private->cmb = NULL;
 875	if (cmb_data)
 876		kfree(cmb_data->last_block);
 877	kfree(cmb_data);
 878	spin_unlock_irq(cdev->ccwlock);
 879
 880	/* deactivate global measurement if this is the last channel */
 881	spin_lock(&cmb_area.lock);
 882	list_del_init(&cdev->private->cmb_list);
 883	if (list_empty(&cmb_area.list))
 884		cmf_activate(NULL, 0);
 885	spin_unlock(&cmb_area.lock);
 886}
 887
 888static int set_cmbe(struct ccw_device *cdev, u32 mme)
 889{
 890	unsigned long mba;
 891	struct cmb_data *cmb_data;
 892	unsigned long flags;
 893
 894	spin_lock_irqsave(cdev->ccwlock, flags);
 895	if (!cdev->private->cmb) {
 896		spin_unlock_irqrestore(cdev->ccwlock, flags);
 897		return -EINVAL;
 898	}
 899	cmb_data = cdev->private->cmb;
 900	mba = mme ? (unsigned long) cmbe_align(cmb_data->hw_block) : 0;
 901	spin_unlock_irqrestore(cdev->ccwlock, flags);
 902
 903	return set_schib_wait(cdev, mme, 1, mba);
 904}
 905
 906
 907static u64 read_cmbe(struct ccw_device *cdev, int index)
 908{
 909	struct cmbe *cmb;
 910	struct cmb_data *cmb_data;
 911	u32 val;
 912	int ret;
 913	unsigned long flags;
 914
 915	ret = cmf_cmb_copy_wait(cdev);
 916	if (ret < 0)
 917		return 0;
 918
 919	spin_lock_irqsave(cdev->ccwlock, flags);
 920	cmb_data = cdev->private->cmb;
 921	if (!cmb_data) {
 922		ret = 0;
 923		goto out;
 924	}
 925	cmb = cmb_data->last_block;
 926
 927	switch (index) {
 928	case cmb_ssch_rsch_count:
 929		ret = cmb->ssch_rsch_count;
 930		goto out;
 931	case cmb_sample_count:
 932		ret = cmb->sample_count;
 933		goto out;
 934	case cmb_device_connect_time:
 935		val = cmb->device_connect_time;
 936		break;
 937	case cmb_function_pending_time:
 938		val = cmb->function_pending_time;
 939		break;
 940	case cmb_device_disconnect_time:
 941		val = cmb->device_disconnect_time;
 942		break;
 943	case cmb_control_unit_queuing_time:
 944		val = cmb->control_unit_queuing_time;
 945		break;
 946	case cmb_device_active_only_time:
 947		val = cmb->device_active_only_time;
 948		break;
 949	case cmb_device_busy_time:
 950		val = cmb->device_busy_time;
 951		break;
 952	case cmb_initial_command_response_time:
 953		val = cmb->initial_command_response_time;
 954		break;
 955	default:
 956		ret = 0;
 957		goto out;
 958	}
 959	ret = time_to_avg_nsec(val, cmb->sample_count);
 960out:
 961	spin_unlock_irqrestore(cdev->ccwlock, flags);
 962	return ret;
 963}
 964
 965static int readall_cmbe(struct ccw_device *cdev, struct cmbdata *data)
 966{
 967	struct cmbe *cmb;
 968	struct cmb_data *cmb_data;
 969	u64 time;
 970	unsigned long flags;
 971	int ret;
 972
 973	ret = cmf_cmb_copy_wait(cdev);
 974	if (ret < 0)
 975		return ret;
 976	spin_lock_irqsave(cdev->ccwlock, flags);
 977	cmb_data = cdev->private->cmb;
 978	if (!cmb_data) {
 979		ret = -ENODEV;
 980		goto out;
 981	}
 982	if (cmb_data->last_update == 0) {
 983		ret = -EAGAIN;
 984		goto out;
 985	}
 986	time = cmb_data->last_update - cdev->private->cmb_start_time;
 987
 988	memset (data, 0, sizeof(struct cmbdata));
 989
 990	/* we only know values before device_busy_time */
 991	data->size = offsetof(struct cmbdata, device_busy_time);
 992
 993	/* conver to nanoseconds */
 994	data->elapsed_time = (time * 1000) >> 12;
 995
 996	cmb = cmb_data->last_block;
 997	/* copy data to new structure */
 998	data->ssch_rsch_count = cmb->ssch_rsch_count;
 999	data->sample_count = cmb->sample_count;
1000
1001	/* time fields are converted to nanoseconds while copying */
1002	data->device_connect_time = time_to_nsec(cmb->device_connect_time);
1003	data->function_pending_time = time_to_nsec(cmb->function_pending_time);
1004	data->device_disconnect_time =
1005		time_to_nsec(cmb->device_disconnect_time);
1006	data->control_unit_queuing_time
1007		= time_to_nsec(cmb->control_unit_queuing_time);
1008	data->device_active_only_time
1009		= time_to_nsec(cmb->device_active_only_time);
1010	data->device_busy_time = time_to_nsec(cmb->device_busy_time);
1011	data->initial_command_response_time
1012		= time_to_nsec(cmb->initial_command_response_time);
1013
1014	ret = 0;
1015out:
1016	spin_unlock_irqrestore(cdev->ccwlock, flags);
1017	return ret;
1018}
1019
1020static void reset_cmbe(struct ccw_device *cdev)
1021{
1022	cmf_generic_reset(cdev);
1023}
1024
1025static void * align_cmbe(void *area)
1026{
1027	return cmbe_align(area);
1028}
1029
1030static struct attribute_group cmf_attr_group_ext;
1031
1032static struct cmb_operations cmbops_extended = {
1033	.alloc	    = alloc_cmbe,
1034	.free	    = free_cmbe,
1035	.set	    = set_cmbe,
1036	.read	    = read_cmbe,
1037	.readall    = readall_cmbe,
1038	.reset	    = reset_cmbe,
1039	.align	    = align_cmbe,
1040	.attr_group = &cmf_attr_group_ext,
1041};
1042
1043static ssize_t cmb_show_attr(struct device *dev, char *buf, enum cmb_index idx)
1044{
1045	return sprintf(buf, "%lld\n",
1046		(unsigned long long) cmf_read(to_ccwdev(dev), idx));
1047}
1048
1049static ssize_t cmb_show_avg_sample_interval(struct device *dev,
1050					    struct device_attribute *attr,
1051					    char *buf)
1052{
1053	struct ccw_device *cdev;
1054	long interval;
1055	unsigned long count;
1056	struct cmb_data *cmb_data;
1057
1058	cdev = to_ccwdev(dev);
1059	count = cmf_read(cdev, cmb_sample_count);
1060	spin_lock_irq(cdev->ccwlock);
1061	cmb_data = cdev->private->cmb;
1062	if (count) {
1063		interval = cmb_data->last_update -
1064			cdev->private->cmb_start_time;
1065		interval = (interval * 1000) >> 12;
1066		interval /= count;
1067	} else
1068		interval = -1;
1069	spin_unlock_irq(cdev->ccwlock);
1070	return sprintf(buf, "%ld\n", interval);
1071}
1072
1073static ssize_t cmb_show_avg_utilization(struct device *dev,
1074					struct device_attribute *attr,
1075					char *buf)
1076{
1077	struct cmbdata data;
1078	u64 utilization;
1079	unsigned long t, u;
1080	int ret;
1081
1082	ret = cmf_readall(to_ccwdev(dev), &data);
1083	if (ret == -EAGAIN || ret == -ENODEV)
1084		/* No data (yet/currently) available to use for calculation. */
1085		return sprintf(buf, "n/a\n");
1086	else if (ret)
1087		return ret;
1088
1089	utilization = data.device_connect_time +
1090		      data.function_pending_time +
1091		      data.device_disconnect_time;
1092
1093	/* shift to avoid long long division */
1094	while (-1ul < (data.elapsed_time | utilization)) {
1095		utilization >>= 8;
1096		data.elapsed_time >>= 8;
1097	}
1098
1099	/* calculate value in 0.1 percent units */
1100	t = (unsigned long) data.elapsed_time / 1000;
1101	u = (unsigned long) utilization / t;
1102
1103	return sprintf(buf, "%02ld.%01ld%%\n", u/ 10, u - (u/ 10) * 10);
1104}
1105
1106#define cmf_attr(name) \
1107static ssize_t show_##name(struct device *dev, \
1108			   struct device_attribute *attr, char *buf)	\
1109{ return cmb_show_attr((dev), buf, cmb_##name); } \
1110static DEVICE_ATTR(name, 0444, show_##name, NULL);
1111
1112#define cmf_attr_avg(name) \
1113static ssize_t show_avg_##name(struct device *dev, \
1114			       struct device_attribute *attr, char *buf) \
1115{ return cmb_show_attr((dev), buf, cmb_##name); } \
1116static DEVICE_ATTR(avg_##name, 0444, show_avg_##name, NULL);
1117
1118cmf_attr(ssch_rsch_count);
1119cmf_attr(sample_count);
1120cmf_attr_avg(device_connect_time);
1121cmf_attr_avg(function_pending_time);
1122cmf_attr_avg(device_disconnect_time);
1123cmf_attr_avg(control_unit_queuing_time);
1124cmf_attr_avg(device_active_only_time);
1125cmf_attr_avg(device_busy_time);
1126cmf_attr_avg(initial_command_response_time);
1127
1128static DEVICE_ATTR(avg_sample_interval, 0444, cmb_show_avg_sample_interval,
1129		   NULL);
1130static DEVICE_ATTR(avg_utilization, 0444, cmb_show_avg_utilization, NULL);
1131
1132static struct attribute *cmf_attributes[] = {
1133	&dev_attr_avg_sample_interval.attr,
1134	&dev_attr_avg_utilization.attr,
1135	&dev_attr_ssch_rsch_count.attr,
1136	&dev_attr_sample_count.attr,
1137	&dev_attr_avg_device_connect_time.attr,
1138	&dev_attr_avg_function_pending_time.attr,
1139	&dev_attr_avg_device_disconnect_time.attr,
1140	&dev_attr_avg_control_unit_queuing_time.attr,
1141	&dev_attr_avg_device_active_only_time.attr,
1142	NULL,
1143};
1144
1145static struct attribute_group cmf_attr_group = {
1146	.name  = "cmf",
1147	.attrs = cmf_attributes,
1148};
1149
1150static struct attribute *cmf_attributes_ext[] = {
1151	&dev_attr_avg_sample_interval.attr,
1152	&dev_attr_avg_utilization.attr,
1153	&dev_attr_ssch_rsch_count.attr,
1154	&dev_attr_sample_count.attr,
1155	&dev_attr_avg_device_connect_time.attr,
1156	&dev_attr_avg_function_pending_time.attr,
1157	&dev_attr_avg_device_disconnect_time.attr,
1158	&dev_attr_avg_control_unit_queuing_time.attr,
1159	&dev_attr_avg_device_active_only_time.attr,
1160	&dev_attr_avg_device_busy_time.attr,
1161	&dev_attr_avg_initial_command_response_time.attr,
1162	NULL,
1163};
1164
1165static struct attribute_group cmf_attr_group_ext = {
1166	.name  = "cmf",
1167	.attrs = cmf_attributes_ext,
1168};
1169
1170static ssize_t cmb_enable_show(struct device *dev,
1171			       struct device_attribute *attr,
1172			       char *buf)
1173{
1174	return sprintf(buf, "%d\n", to_ccwdev(dev)->private->cmb ? 1 : 0);
1175}
1176
1177static ssize_t cmb_enable_store(struct device *dev,
1178				struct device_attribute *attr, const char *buf,
1179				size_t c)
1180{
1181	struct ccw_device *cdev;
1182	int ret;
1183	unsigned long val;
1184
1185	ret = kstrtoul(buf, 16, &val);
1186	if (ret)
1187		return ret;
1188
1189	cdev = to_ccwdev(dev);
1190
1191	switch (val) {
1192	case 0:
1193		ret = disable_cmf(cdev);
1194		break;
1195	case 1:
1196		ret = enable_cmf(cdev);
1197		break;
1198	}
1199
1200	return c;
1201}
1202
1203DEVICE_ATTR(cmb_enable, 0644, cmb_enable_show, cmb_enable_store);
1204
1205int ccw_set_cmf(struct ccw_device *cdev, int enable)
1206{
1207	return cmbops->set(cdev, enable ? 2 : 0);
1208}
1209
1210/**
1211 * enable_cmf() - switch on the channel measurement for a specific device
1212 *  @cdev:	The ccw device to be enabled
1213 *
1214 *  Returns %0 for success or a negative error value.
1215 *
1216 *  Context:
1217 *    non-atomic
1218 */
1219int enable_cmf(struct ccw_device *cdev)
1220{
1221	int ret;
1222
1223	ret = cmbops->alloc(cdev);
1224	cmbops->reset(cdev);
1225	if (ret)
1226		return ret;
1227	ret = cmbops->set(cdev, 2);
1228	if (ret) {
1229		cmbops->free(cdev);
1230		return ret;
1231	}
1232	ret = sysfs_create_group(&cdev->dev.kobj, cmbops->attr_group);
1233	if (!ret)
1234		return 0;
1235	cmbops->set(cdev, 0);  //FIXME: this can fail
1236	cmbops->free(cdev);
1237	return ret;
1238}
1239
1240/**
1241 * disable_cmf() - switch off the channel measurement for a specific device
1242 *  @cdev:	The ccw device to be disabled
1243 *
1244 *  Returns %0 for success or a negative error value.
1245 *
1246 *  Context:
1247 *    non-atomic
1248 */
1249int disable_cmf(struct ccw_device *cdev)
1250{
1251	int ret;
1252
1253	ret = cmbops->set(cdev, 0);
1254	if (ret)
1255		return ret;
1256	cmbops->free(cdev);
1257	sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
1258	return ret;
1259}
1260
1261/**
1262 * cmf_read() - read one value from the current channel measurement block
1263 * @cdev:	the channel to be read
1264 * @index:	the index of the value to be read
1265 *
1266 * Returns the value read or %0 if the value cannot be read.
1267 *
1268 *  Context:
1269 *    any
1270 */
1271u64 cmf_read(struct ccw_device *cdev, int index)
1272{
1273	return cmbops->read(cdev, index);
1274}
1275
1276/**
1277 * cmf_readall() - read the current channel measurement block
1278 * @cdev:	the channel to be read
1279 * @data:	a pointer to a data block that will be filled
1280 *
1281 * Returns %0 on success, a negative error value otherwise.
1282 *
1283 *  Context:
1284 *    any
1285 */
1286int cmf_readall(struct ccw_device *cdev, struct cmbdata *data)
1287{
1288	return cmbops->readall(cdev, data);
1289}
1290
1291/* Reenable cmf when a disconnected device becomes available again. */
1292int cmf_reenable(struct ccw_device *cdev)
1293{
1294	cmbops->reset(cdev);
1295	return cmbops->set(cdev, 2);
1296}
1297
1298static int __init init_cmf(void)
1299{
1300	char *format_string;
1301	char *detect_string = "parameter";
1302
1303	/*
1304	 * If the user did not give a parameter, see if we are running on a
1305	 * machine supporting extended measurement blocks, otherwise fall back
1306	 * to basic mode.
1307	 */
1308	if (format == CMF_AUTODETECT) {
1309		if (!css_general_characteristics.ext_mb) {
1310			format = CMF_BASIC;
1311		} else {
1312			format = CMF_EXTENDED;
1313		}
1314		detect_string = "autodetected";
1315	} else {
1316		detect_string = "parameter";
1317	}
1318
1319	switch (format) {
1320	case CMF_BASIC:
1321		format_string = "basic";
1322		cmbops = &cmbops_basic;
1323		break;
1324	case CMF_EXTENDED:
1325		format_string = "extended";
1326		cmbops = &cmbops_extended;
1327		break;
1328	default:
1329		return 1;
1330	}
1331	pr_info("Channel measurement facility initialized using format "
1332		"%s (mode %s)\n", format_string, detect_string);
1333	return 0;
1334}
1335
1336module_init(init_cmf);
1337
1338
1339MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
1340MODULE_LICENSE("GPL");
1341MODULE_DESCRIPTION("channel measurement facility base driver\n"
1342		   "Copyright IBM Corp. 2003\n");
1343
1344EXPORT_SYMBOL_GPL(enable_cmf);
1345EXPORT_SYMBOL_GPL(disable_cmf);
1346EXPORT_SYMBOL_GPL(cmf_read);
1347EXPORT_SYMBOL_GPL(cmf_readall);