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