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 */
47enum cmb_index {
48 avg_utilization = -1,
49 /* basic and exended format: */
50 cmb_ssch_rsch_count = 0,
51 cmb_sample_count,
52 cmb_device_connect_time,
53 cmb_function_pending_time,
54 cmb_device_disconnect_time,
55 cmb_control_unit_queuing_time,
56 cmb_device_active_only_time,
57 /* extended format only: */
58 cmb_device_busy_time,
59 cmb_initial_command_response_time,
60};
61
62/**
63 * enum cmb_format - types of supported measurement block formats
64 *
65 * @CMF_BASIC: traditional channel measurement blocks supported
66 * by all machines that we run on
67 * @CMF_EXTENDED: improved format that was introduced with the z990
68 * machine
69 * @CMF_AUTODETECT: default: use extended format when running on a machine
70 * supporting extended format, otherwise fall back to
71 * basic format
72 */
73enum 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 */
86static int format = CMF_AUTODETECT;
87module_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 */
105struct 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};
115static struct cmb_operations *cmbops;
116
117struct 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 */
129static inline u64 time_to_nsec(u32 value)
130{
131 return ((u64)value) * 128000ull;
132}
133
134/*
135 * Users are usually interested in average times,
136 * not accumulated time.
137 * This also helps us with atomicity problems
138 * when reading sinlge values.
139 */
140static 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 */
164static inline void cmf_activate(void *area, unsigned int onoff)
165{
166 /* activate channel measurement */
167 asm volatile(
168 " lgr 1,%[r1]\n"
169 " lgr 2,%[mbo]\n"
170 " schm\n"
171 :
172 : [r1] "d" ((unsigned long)onoff), [mbo] "d" (area)
173 : "1", "2");
174}
175
176static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
177 unsigned long address)
178{
179 struct subchannel *sch = to_subchannel(cdev->dev.parent);
180 int ret;
181
182 sch->config.mme = mme;
183 sch->config.mbfc = mbfc;
184 /* address can be either a block address or a block index */
185 if (mbfc)
186 sch->config.mba = address;
187 else
188 sch->config.mbi = address;
189
190 ret = cio_commit_config(sch);
191 if (!mme && ret == -ENODEV) {
192 /*
193 * The task was to disable measurement block updates but
194 * the subchannel is already gone. Report success.
195 */
196 ret = 0;
197 }
198 return ret;
199}
200
201struct set_schib_struct {
202 u32 mme;
203 int mbfc;
204 unsigned long address;
205 wait_queue_head_t wait;
206 int ret;
207};
208
209#define CMF_PENDING 1
210#define SET_SCHIB_TIMEOUT (10 * HZ)
211
212static int set_schib_wait(struct ccw_device *cdev, u32 mme,
213 int mbfc, unsigned long address)
214{
215 struct set_schib_struct set_data;
216 int ret = -ENODEV;
217
218 spin_lock_irq(lock: cdev->ccwlock);
219 if (!cdev->private->cmb)
220 goto out;
221
222 ret = set_schib(cdev, mme, mbfc, address);
223 if (ret != -EBUSY)
224 goto out;
225
226 /* if the device is not online, don't even try again */
227 if (cdev->private->state != DEV_STATE_ONLINE)
228 goto out;
229
230 init_waitqueue_head(&set_data.wait);
231 set_data.mme = mme;
232 set_data.mbfc = mbfc;
233 set_data.address = address;
234 set_data.ret = CMF_PENDING;
235
236 cdev->private->state = DEV_STATE_CMFCHANGE;
237 cdev->private->cmb_wait = &set_data;
238 spin_unlock_irq(lock: cdev->ccwlock);
239
240 ret = wait_event_interruptible_timeout(set_data.wait,
241 set_data.ret != CMF_PENDING,
242 SET_SCHIB_TIMEOUT);
243 spin_lock_irq(lock: cdev->ccwlock);
244 if (ret <= 0) {
245 if (set_data.ret == CMF_PENDING) {
246 set_data.ret = (ret == 0) ? -ETIME : ret;
247 if (cdev->private->state == DEV_STATE_CMFCHANGE)
248 cdev->private->state = DEV_STATE_ONLINE;
249 }
250 }
251 cdev->private->cmb_wait = NULL;
252 ret = set_data.ret;
253out:
254 spin_unlock_irq(lock: cdev->ccwlock);
255 return ret;
256}
257
258void retry_set_schib(struct ccw_device *cdev)
259{
260 struct set_schib_struct *set_data = cdev->private->cmb_wait;
261
262 if (!set_data)
263 return;
264
265 set_data->ret = set_schib(cdev, mme: set_data->mme, mbfc: set_data->mbfc,
266 address: set_data->address);
267 wake_up(&set_data->wait);
268}
269
270static int cmf_copy_block(struct ccw_device *cdev)
271{
272 struct subchannel *sch = to_subchannel(cdev->dev.parent);
273 struct cmb_data *cmb_data;
274 void *hw_block;
275
276 if (cio_update_schib(sch))
277 return -ENODEV;
278
279 if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
280 /* Don't copy if a start function is in progress. */
281 if ((!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_SUSPENDED)) &&
282 (scsw_actl(&sch->schib.scsw) &
283 (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) &&
284 (!(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_SEC_STATUS)))
285 return -EBUSY;
286 }
287 cmb_data = cdev->private->cmb;
288 hw_block = cmb_data->hw_block;
289 memcpy(cmb_data->last_block, hw_block, cmb_data->size);
290 cmb_data->last_update = get_tod_clock();
291 return 0;
292}
293
294struct copy_block_struct {
295 wait_queue_head_t wait;
296 int ret;
297};
298
299static int cmf_cmb_copy_wait(struct ccw_device *cdev)
300{
301 struct copy_block_struct copy_block;
302 int ret = -ENODEV;
303
304 spin_lock_irq(lock: cdev->ccwlock);
305 if (!cdev->private->cmb)
306 goto out;
307
308 ret = cmf_copy_block(cdev);
309 if (ret != -EBUSY)
310 goto out;
311
312 if (cdev->private->state != DEV_STATE_ONLINE)
313 goto out;
314
315 init_waitqueue_head(&copy_block.wait);
316 copy_block.ret = CMF_PENDING;
317
318 cdev->private->state = DEV_STATE_CMFUPDATE;
319 cdev->private->cmb_wait = &copy_block;
320 spin_unlock_irq(lock: cdev->ccwlock);
321
322 ret = wait_event_interruptible(copy_block.wait,
323 copy_block.ret != CMF_PENDING);
324 spin_lock_irq(lock: cdev->ccwlock);
325 if (ret) {
326 if (copy_block.ret == CMF_PENDING) {
327 copy_block.ret = -ERESTARTSYS;
328 if (cdev->private->state == DEV_STATE_CMFUPDATE)
329 cdev->private->state = DEV_STATE_ONLINE;
330 }
331 }
332 cdev->private->cmb_wait = NULL;
333 ret = copy_block.ret;
334out:
335 spin_unlock_irq(lock: cdev->ccwlock);
336 return ret;
337}
338
339void cmf_retry_copy_block(struct ccw_device *cdev)
340{
341 struct copy_block_struct *copy_block = cdev->private->cmb_wait;
342
343 if (!copy_block)
344 return;
345
346 copy_block->ret = cmf_copy_block(cdev);
347 wake_up(&copy_block->wait);
348}
349
350static void cmf_generic_reset(struct ccw_device *cdev)
351{
352 struct cmb_data *cmb_data;
353
354 spin_lock_irq(lock: cdev->ccwlock);
355 cmb_data = cdev->private->cmb;
356 if (cmb_data) {
357 memset(cmb_data->last_block, 0, cmb_data->size);
358 /*
359 * Need to reset hw block as well to make the hardware start
360 * from 0 again.
361 */
362 memset(cmb_data->hw_block, 0, cmb_data->size);
363 cmb_data->last_update = 0;
364 }
365 cdev->private->cmb_start_time = get_tod_clock();
366 spin_unlock_irq(lock: cdev->ccwlock);
367}
368
369/**
370 * struct cmb_area - container for global cmb data
371 *
372 * @mem: pointer to CMBs (only in basic measurement mode)
373 * @list: contains a linked list of all subchannels
374 * @num_channels: number of channels to be measured
375 * @lock: protect concurrent access to @mem and @list
376 */
377struct cmb_area {
378 struct cmb *mem;
379 struct list_head list;
380 int num_channels;
381 spinlock_t lock;
382};
383
384static struct cmb_area cmb_area = {
385 .lock = __SPIN_LOCK_UNLOCKED(cmb_area.lock),
386 .list = LIST_HEAD_INIT(cmb_area.list),
387 .num_channels = 1024,
388};
389
390/* ****** old style CMB handling ********/
391
392/*
393 * Basic channel measurement blocks are allocated in one contiguous
394 * block of memory, which can not be moved as long as any channel
395 * is active. Therefore, a maximum number of subchannels needs to
396 * be defined somewhere. This is a module parameter, defaulting to
397 * a reasonable value of 1024, or 32 kb of memory.
398 * Current kernels don't allow kmalloc with more than 128kb, so the
399 * maximum is 4096.
400 */
401
402module_param_named(maxchannels, cmb_area.num_channels, uint, 0444);
403
404/**
405 * struct cmb - basic channel measurement block
406 * @ssch_rsch_count: number of ssch and rsch
407 * @sample_count: number of samples
408 * @device_connect_time: time of device connect
409 * @function_pending_time: time of function pending
410 * @device_disconnect_time: time of device disconnect
411 * @control_unit_queuing_time: time of control unit queuing
412 * @device_active_only_time: time of device active only
413 * @reserved: unused in basic measurement mode
414 *
415 * The measurement block as used by the hardware. The fields are described
416 * further in z/Architecture Principles of Operation, chapter 17.
417 *
418 * The cmb area made up from these blocks must be a contiguous array and may
419 * not be reallocated or freed.
420 * Only one cmb area can be present in the system.
421 */
422struct cmb {
423 u16 ssch_rsch_count;
424 u16 sample_count;
425 u32 device_connect_time;
426 u32 function_pending_time;
427 u32 device_disconnect_time;
428 u32 control_unit_queuing_time;
429 u32 device_active_only_time;
430 u32 reserved[2];
431};
432
433/*
434 * Insert a single device into the cmb_area list.
435 * Called with cmb_area.lock held from alloc_cmb.
436 */
437static int alloc_cmb_single(struct ccw_device *cdev,
438 struct cmb_data *cmb_data)
439{
440 struct cmb *cmb;
441 struct ccw_device_private *node;
442 int ret;
443
444 spin_lock_irq(lock: cdev->ccwlock);
445 if (!list_empty(head: &cdev->private->cmb_list)) {
446 ret = -EBUSY;
447 goto out;
448 }
449
450 /*
451 * Find first unused cmb in cmb_area.mem.
452 * This is a little tricky: cmb_area.list
453 * remains sorted by ->cmb->hw_data pointers.
454 */
455 cmb = cmb_area.mem;
456 list_for_each_entry(node, &cmb_area.list, cmb_list) {
457 struct cmb_data *data;
458 data = node->cmb;
459 if ((struct cmb*)data->hw_block > cmb)
460 break;
461 cmb++;
462 }
463 if (cmb - cmb_area.mem >= cmb_area.num_channels) {
464 ret = -ENOMEM;
465 goto out;
466 }
467
468 /* insert new cmb */
469 list_add_tail(new: &cdev->private->cmb_list, head: &node->cmb_list);
470 cmb_data->hw_block = cmb;
471 cdev->private->cmb = cmb_data;
472 ret = 0;
473out:
474 spin_unlock_irq(lock: cdev->ccwlock);
475 return ret;
476}
477
478static int alloc_cmb(struct ccw_device *cdev)
479{
480 int ret;
481 struct cmb *mem;
482 ssize_t size;
483 struct cmb_data *cmb_data;
484
485 /* Allocate private cmb_data. */
486 cmb_data = kzalloc(size: sizeof(struct cmb_data), GFP_KERNEL);
487 if (!cmb_data)
488 return -ENOMEM;
489
490 cmb_data->last_block = kzalloc(size: sizeof(struct cmb), GFP_KERNEL);
491 if (!cmb_data->last_block) {
492 kfree(objp: cmb_data);
493 return -ENOMEM;
494 }
495 cmb_data->size = sizeof(struct cmb);
496 spin_lock(lock: &cmb_area.lock);
497
498 if (!cmb_area.mem) {
499 /* there is no user yet, so we need a new area */
500 size = sizeof(struct cmb) * cmb_area.num_channels;
501 WARN_ON(!list_empty(&cmb_area.list));
502
503 spin_unlock(lock: &cmb_area.lock);
504 mem = (void*)__get_free_pages(GFP_KERNEL | GFP_DMA,
505 order: get_order(size));
506 spin_lock(lock: &cmb_area.lock);
507
508 if (cmb_area.mem) {
509 /* ok, another thread was faster */
510 free_pages(addr: (unsigned long)mem, order: 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(area: cmb_area.mem, CMF_ON);
520 }
521 }
522
523 /* do the actual allocation */
524 ret = alloc_cmb_single(cdev, cmb_data);
525out:
526 spin_unlock(lock: &cmb_area.lock);
527 if (ret) {
528 kfree(objp: cmb_data->last_block);
529 kfree(objp: cmb_data);
530 }
531 return ret;
532}
533
534static void free_cmb(struct ccw_device *cdev)
535{
536 struct ccw_device_private *priv;
537 struct cmb_data *cmb_data;
538
539 spin_lock(lock: &cmb_area.lock);
540 spin_lock_irq(lock: cdev->ccwlock);
541
542 priv = cdev->private;
543 cmb_data = priv->cmb;
544 priv->cmb = NULL;
545 if (cmb_data)
546 kfree(objp: cmb_data->last_block);
547 kfree(objp: cmb_data);
548 list_del_init(entry: &priv->cmb_list);
549
550 if (list_empty(head: &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(addr: (unsigned long)cmb_area.mem, order: get_order(size));
555 cmb_area.mem = NULL;
556 }
557 spin_unlock_irq(lock: cdev->ccwlock);
558 spin_unlock(lock: &cmb_area.lock);
559}
560
561static 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(lock: 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(lock: cdev->ccwlock, flags);
575
576 return set_schib_wait(cdev, mme, mbfc: 0, address: offset);
577}
578
579/* calculate utilization in 0.1 percent units */
580static 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(value: 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
596static 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(device_connect_time: cmb->device_connect_time,
613 function_pending_time: cmb->function_pending_time,
614 device_disconnect_time: cmb->device_disconnect_time,
615 start_time: 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(value: val, count: cmb->sample_count);
642out:
643 spin_unlock_irqrestore(lock: cdev->ccwlock, flags);
644 return ret;
645}
646
647static 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(value: cmb->device_connect_time);
684 data->function_pending_time = time_to_nsec(value: cmb->function_pending_time);
685 data->device_disconnect_time =
686 time_to_nsec(value: cmb->device_disconnect_time);
687 data->control_unit_queuing_time
688 = time_to_nsec(value: cmb->control_unit_queuing_time);
689 data->device_active_only_time
690 = time_to_nsec(value: cmb->device_active_only_time);
691 ret = 0;
692out:
693 spin_unlock_irqrestore(lock: cdev->ccwlock, flags);
694 return ret;
695}
696
697static void reset_cmb(struct ccw_device *cdev)
698{
699 cmf_generic_reset(cdev);
700}
701
702static int cmf_enabled(struct ccw_device *cdev)
703{
704 int enabled;
705
706 spin_lock_irq(lock: cdev->ccwlock);
707 enabled = !!cdev->private->cmb;
708 spin_unlock_irq(lock: cdev->ccwlock);
709
710 return enabled;
711}
712
713static struct attribute_group cmf_attr_group;
714
715static 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 */
745struct 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
758static struct kmem_cache *cmbe_cache;
759
760static 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(k: cmbe_cache, GFP_KERNEL);
767 if (!cmbe)
768 return ret;
769
770 cmb_data = kzalloc(size: sizeof(*cmb_data), GFP_KERNEL);
771 if (!cmb_data)
772 goto out_free;
773
774 cmb_data->last_block = kzalloc(size: 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(lock: &cmb_area.lock);
782 spin_lock_irq(lock: 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(head: &cmb_area.list))
790 cmf_activate(NULL, CMF_ON);
791 list_add_tail(new: &cdev->private->cmb_list, head: &cmb_area.list);
792
793 spin_unlock_irq(lock: cdev->ccwlock);
794 spin_unlock(lock: &cmb_area.lock);
795 return 0;
796
797out_unlock:
798 spin_unlock_irq(lock: cdev->ccwlock);
799 spin_unlock(lock: &cmb_area.lock);
800 ret = -EBUSY;
801out_free:
802 if (cmb_data)
803 kfree(objp: cmb_data->last_block);
804 kfree(objp: cmb_data);
805 kmem_cache_free(s: cmbe_cache, objp: cmbe);
806
807 return ret;
808}
809
810static void free_cmbe(struct ccw_device *cdev)
811{
812 struct cmb_data *cmb_data;
813
814 spin_lock(lock: &cmb_area.lock);
815 spin_lock_irq(lock: cdev->ccwlock);
816 cmb_data = cdev->private->cmb;
817 cdev->private->cmb = NULL;
818 if (cmb_data) {
819 kfree(objp: cmb_data->last_block);
820 kmem_cache_free(s: cmbe_cache, objp: cmb_data->hw_block);
821 }
822 kfree(objp: cmb_data);
823
824 /* deactivate global measurement if this is the last channel */
825 list_del_init(entry: &cdev->private->cmb_list);
826 if (list_empty(head: &cmb_area.list))
827 cmf_activate(NULL, CMF_OFF);
828 spin_unlock_irq(lock: cdev->ccwlock);
829 spin_unlock(lock: &cmb_area.lock);
830}
831
832static 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(lock: 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(lock: cdev->ccwlock, flags);
846
847 return set_schib_wait(cdev, mme, mbfc: 1, address: mba);
848}
849
850static 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(device_connect_time: cmb->device_connect_time,
867 function_pending_time: cmb->function_pending_time,
868 device_disconnect_time: cmb->device_disconnect_time,
869 start_time: 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(value: val, count: cmb->sample_count);
902out:
903 spin_unlock_irqrestore(lock: cdev->ccwlock, flags);
904 return ret;
905}
906
907static 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(value: cmb->device_connect_time);
944 data->function_pending_time = time_to_nsec(value: cmb->function_pending_time);
945 data->device_disconnect_time =
946 time_to_nsec(value: cmb->device_disconnect_time);
947 data->control_unit_queuing_time
948 = time_to_nsec(value: cmb->control_unit_queuing_time);
949 data->device_active_only_time
950 = time_to_nsec(value: cmb->device_active_only_time);
951 data->device_busy_time = time_to_nsec(value: cmb->device_busy_time);
952 data->initial_command_response_time
953 = time_to_nsec(value: cmb->initial_command_response_time);
954
955 ret = 0;
956out:
957 spin_unlock_irqrestore(lock: cdev->ccwlock, flags);
958 return ret;
959}
960
961static void reset_cmbe(struct ccw_device *cdev)
962{
963 cmf_generic_reset(cdev);
964}
965
966static struct attribute_group cmf_attr_group_ext;
967
968static 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
978static ssize_t cmb_show_attr(struct device *dev, char *buf, enum cmb_index idx)
979{
980 return sprintf(buf, fmt: "%lld\n",
981 (unsigned long long) cmf_read(to_ccwdev(dev), idx));
982}
983
984static ssize_t cmb_show_avg_sample_interval(struct device *dev,
985 struct device_attribute *attr,
986 char *buf)
987{
988 struct ccw_device *cdev = to_ccwdev(dev);
989 unsigned long count;
990 long interval;
991
992 count = cmf_read(cdev, cmb_sample_count);
993 spin_lock_irq(lock: cdev->ccwlock);
994 if (count) {
995 interval = get_tod_clock() - cdev->private->cmb_start_time;
996 interval = tod_to_ns(interval);
997 interval /= count;
998 } else
999 interval = -1;
1000 spin_unlock_irq(lock: cdev->ccwlock);
1001 return sprintf(buf, fmt: "%ld\n", interval);
1002}
1003
1004static ssize_t cmb_show_avg_utilization(struct device *dev,
1005 struct device_attribute *attr,
1006 char *buf)
1007{
1008 unsigned long u = cmf_read(to_ccwdev(dev), avg_utilization);
1009
1010 return sprintf(buf, fmt: "%02lu.%01lu%%\n", u / 10, u % 10);
1011}
1012
1013#define cmf_attr(name) \
1014static ssize_t show_##name(struct device *dev, \
1015 struct device_attribute *attr, char *buf) \
1016{ return cmb_show_attr((dev), buf, cmb_##name); } \
1017static DEVICE_ATTR(name, 0444, show_##name, NULL);
1018
1019#define cmf_attr_avg(name) \
1020static ssize_t show_avg_##name(struct device *dev, \
1021 struct device_attribute *attr, char *buf) \
1022{ return cmb_show_attr((dev), buf, cmb_##name); } \
1023static DEVICE_ATTR(avg_##name, 0444, show_avg_##name, NULL);
1024
1025cmf_attr(ssch_rsch_count);
1026cmf_attr(sample_count);
1027cmf_attr_avg(device_connect_time);
1028cmf_attr_avg(function_pending_time);
1029cmf_attr_avg(device_disconnect_time);
1030cmf_attr_avg(control_unit_queuing_time);
1031cmf_attr_avg(device_active_only_time);
1032cmf_attr_avg(device_busy_time);
1033cmf_attr_avg(initial_command_response_time);
1034
1035static DEVICE_ATTR(avg_sample_interval, 0444, cmb_show_avg_sample_interval,
1036 NULL);
1037static DEVICE_ATTR(avg_utilization, 0444, cmb_show_avg_utilization, NULL);
1038
1039static struct attribute *cmf_attributes[] = {
1040 &dev_attr_avg_sample_interval.attr,
1041 &dev_attr_avg_utilization.attr,
1042 &dev_attr_ssch_rsch_count.attr,
1043 &dev_attr_sample_count.attr,
1044 &dev_attr_avg_device_connect_time.attr,
1045 &dev_attr_avg_function_pending_time.attr,
1046 &dev_attr_avg_device_disconnect_time.attr,
1047 &dev_attr_avg_control_unit_queuing_time.attr,
1048 &dev_attr_avg_device_active_only_time.attr,
1049 NULL,
1050};
1051
1052static struct attribute_group cmf_attr_group = {
1053 .name = "cmf",
1054 .attrs = cmf_attributes,
1055};
1056
1057static struct attribute *cmf_attributes_ext[] = {
1058 &dev_attr_avg_sample_interval.attr,
1059 &dev_attr_avg_utilization.attr,
1060 &dev_attr_ssch_rsch_count.attr,
1061 &dev_attr_sample_count.attr,
1062 &dev_attr_avg_device_connect_time.attr,
1063 &dev_attr_avg_function_pending_time.attr,
1064 &dev_attr_avg_device_disconnect_time.attr,
1065 &dev_attr_avg_control_unit_queuing_time.attr,
1066 &dev_attr_avg_device_active_only_time.attr,
1067 &dev_attr_avg_device_busy_time.attr,
1068 &dev_attr_avg_initial_command_response_time.attr,
1069 NULL,
1070};
1071
1072static struct attribute_group cmf_attr_group_ext = {
1073 .name = "cmf",
1074 .attrs = cmf_attributes_ext,
1075};
1076
1077static ssize_t cmb_enable_show(struct device *dev,
1078 struct device_attribute *attr,
1079 char *buf)
1080{
1081 struct ccw_device *cdev = to_ccwdev(dev);
1082
1083 return sprintf(buf, fmt: "%d\n", cmf_enabled(cdev));
1084}
1085
1086static ssize_t cmb_enable_store(struct device *dev,
1087 struct device_attribute *attr, const char *buf,
1088 size_t c)
1089{
1090 struct ccw_device *cdev = to_ccwdev(dev);
1091 unsigned long val;
1092 int ret;
1093
1094 ret = kstrtoul(s: buf, base: 16, res: &val);
1095 if (ret)
1096 return ret;
1097
1098 switch (val) {
1099 case 0:
1100 ret = disable_cmf(cdev);
1101 break;
1102 case 1:
1103 ret = enable_cmf(cdev);
1104 break;
1105 default:
1106 ret = -EINVAL;
1107 }
1108
1109 return ret ? ret : c;
1110}
1111DEVICE_ATTR_RW(cmb_enable);
1112
1113/**
1114 * enable_cmf() - switch on the channel measurement for a specific device
1115 * @cdev: The ccw device to be enabled
1116 *
1117 * Enable channel measurements for @cdev. If this is called on a device
1118 * for which channel measurement is already enabled a reset of the
1119 * measurement data is triggered.
1120 * Returns: %0 for success or a negative error value.
1121 * Context:
1122 * non-atomic
1123 */
1124int enable_cmf(struct ccw_device *cdev)
1125{
1126 int ret = 0;
1127
1128 device_lock(dev: &cdev->dev);
1129 if (cmf_enabled(cdev)) {
1130 cmbops->reset(cdev);
1131 goto out_unlock;
1132 }
1133 get_device(dev: &cdev->dev);
1134 ret = cmbops->alloc(cdev);
1135 if (ret)
1136 goto out;
1137 cmbops->reset(cdev);
1138 ret = sysfs_create_group(kobj: &cdev->dev.kobj, grp: cmbops->attr_group);
1139 if (ret) {
1140 cmbops->free(cdev);
1141 goto out;
1142 }
1143 ret = cmbops->set(cdev, 2);
1144 if (ret) {
1145 sysfs_remove_group(kobj: &cdev->dev.kobj, grp: cmbops->attr_group);
1146 cmbops->free(cdev);
1147 }
1148out:
1149 if (ret)
1150 put_device(dev: &cdev->dev);
1151out_unlock:
1152 device_unlock(dev: &cdev->dev);
1153 return ret;
1154}
1155
1156/**
1157 * __disable_cmf() - switch off the channel measurement for a specific device
1158 * @cdev: The ccw device to be disabled
1159 *
1160 * Returns: %0 for success or a negative error value.
1161 *
1162 * Context:
1163 * non-atomic, device_lock() held.
1164 */
1165int __disable_cmf(struct ccw_device *cdev)
1166{
1167 int ret;
1168
1169 ret = cmbops->set(cdev, 0);
1170 if (ret)
1171 return ret;
1172
1173 sysfs_remove_group(kobj: &cdev->dev.kobj, grp: cmbops->attr_group);
1174 cmbops->free(cdev);
1175 put_device(dev: &cdev->dev);
1176
1177 return ret;
1178}
1179
1180/**
1181 * disable_cmf() - switch off the channel measurement for a specific device
1182 * @cdev: The ccw device to be disabled
1183 *
1184 * Returns: %0 for success or a negative error value.
1185 *
1186 * Context:
1187 * non-atomic
1188 */
1189int disable_cmf(struct ccw_device *cdev)
1190{
1191 int ret;
1192
1193 device_lock(dev: &cdev->dev);
1194 ret = __disable_cmf(cdev);
1195 device_unlock(dev: &cdev->dev);
1196
1197 return ret;
1198}
1199
1200/**
1201 * cmf_read() - read one value from the current channel measurement block
1202 * @cdev: the channel to be read
1203 * @index: the index of the value to be read
1204 *
1205 * Returns: The value read or %0 if the value cannot be read.
1206 *
1207 * Context:
1208 * any
1209 */
1210u64 cmf_read(struct ccw_device *cdev, int index)
1211{
1212 return cmbops->read(cdev, index);
1213}
1214
1215/**
1216 * cmf_readall() - read the current channel measurement block
1217 * @cdev: the channel to be read
1218 * @data: a pointer to a data block that will be filled
1219 *
1220 * Returns: %0 on success, a negative error value otherwise.
1221 *
1222 * Context:
1223 * any
1224 */
1225int cmf_readall(struct ccw_device *cdev, struct cmbdata *data)
1226{
1227 return cmbops->readall(cdev, data);
1228}
1229
1230/* Reenable cmf when a disconnected device becomes available again. */
1231int cmf_reenable(struct ccw_device *cdev)
1232{
1233 cmbops->reset(cdev);
1234 return cmbops->set(cdev, 2);
1235}
1236
1237/**
1238 * cmf_reactivate() - reactivate measurement block updates
1239 *
1240 * Use this during resume from hibernate.
1241 */
1242void cmf_reactivate(void)
1243{
1244 spin_lock(lock: &cmb_area.lock);
1245 if (!list_empty(head: &cmb_area.list))
1246 cmf_activate(area: cmb_area.mem, CMF_ON);
1247 spin_unlock(lock: &cmb_area.lock);
1248}
1249
1250static int __init init_cmbe(void)
1251{
1252 cmbe_cache = kmem_cache_create(name: "cmbe_cache", size: sizeof(struct cmbe),
1253 align: __alignof__(struct cmbe), flags: 0, NULL);
1254
1255 return cmbe_cache ? 0 : -ENOMEM;
1256}
1257
1258static int __init init_cmf(void)
1259{
1260 char *format_string;
1261 char *detect_string;
1262 int ret;
1263
1264 /*
1265 * If the user did not give a parameter, see if we are running on a
1266 * machine supporting extended measurement blocks, otherwise fall back
1267 * to basic mode.
1268 */
1269 if (format == CMF_AUTODETECT) {
1270 if (!css_general_characteristics.ext_mb) {
1271 format = CMF_BASIC;
1272 } else {
1273 format = CMF_EXTENDED;
1274 }
1275 detect_string = "autodetected";
1276 } else {
1277 detect_string = "parameter";
1278 }
1279
1280 switch (format) {
1281 case CMF_BASIC:
1282 format_string = "basic";
1283 cmbops = &cmbops_basic;
1284 break;
1285 case CMF_EXTENDED:
1286 format_string = "extended";
1287 cmbops = &cmbops_extended;
1288
1289 ret = init_cmbe();
1290 if (ret)
1291 return ret;
1292 break;
1293 default:
1294 return -EINVAL;
1295 }
1296 pr_info("Channel measurement facility initialized using format "
1297 "%s (mode %s)\n", format_string, detect_string);
1298 return 0;
1299}
1300device_initcall(init_cmf);
1301
1302EXPORT_SYMBOL_GPL(enable_cmf);
1303EXPORT_SYMBOL_GPL(disable_cmf);
1304EXPORT_SYMBOL_GPL(cmf_read);
1305EXPORT_SYMBOL_GPL(cmf_readall);
1306

source code of linux/drivers/s390/cio/cmf.c