update checkpatch.pl to version 0.05
[pv_ops_mirror.git] / drivers / s390 / cio / chp.c
blobac289e6eadfe9ea1ef0a54c7d0de74b68c243108
1 /*
2 * drivers/s390/cio/chp.c
4 * Copyright IBM Corp. 1999,2007
5 * Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
6 * Arnd Bergmann (arndb@de.ibm.com)
7 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
8 */
10 #include <linux/bug.h>
11 #include <linux/workqueue.h>
12 #include <linux/spinlock.h>
13 #include <linux/init.h>
14 #include <linux/jiffies.h>
15 #include <linux/wait.h>
16 #include <linux/mutex.h>
17 #include <asm/errno.h>
18 #include <asm/chpid.h>
19 #include <asm/sclp.h>
21 #include "cio.h"
22 #include "css.h"
23 #include "ioasm.h"
24 #include "cio_debug.h"
25 #include "chp.h"
27 #define to_channelpath(device) container_of(device, struct channel_path, dev)
28 #define CHP_INFO_UPDATE_INTERVAL 1*HZ
30 enum cfg_task_t {
31 cfg_none,
32 cfg_configure,
33 cfg_deconfigure
36 /* Map for pending configure tasks. */
37 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
38 static DEFINE_MUTEX(cfg_lock);
39 static int cfg_busy;
41 /* Map for channel-path status. */
42 static struct sclp_chp_info chp_info;
43 static DEFINE_MUTEX(info_lock);
45 /* Time after which channel-path status may be outdated. */
46 static unsigned long chp_info_expires;
48 /* Workqueue to perform pending configure tasks. */
49 static struct workqueue_struct *chp_wq;
50 static struct work_struct cfg_work;
52 /* Wait queue for configure completion events. */
53 static wait_queue_head_t cfg_wait_queue;
55 /* Return channel_path struct for given chpid. */
56 static inline struct channel_path *chpid_to_chp(struct chp_id chpid)
58 return css[chpid.cssid]->chps[chpid.id];
61 /* Set vary state for given chpid. */
62 static void set_chp_logically_online(struct chp_id chpid, int onoff)
64 chpid_to_chp(chpid)->state = onoff;
67 /* On succes return 0 if channel-path is varied offline, 1 if it is varied
68 * online. Return -ENODEV if channel-path is not registered. */
69 int chp_get_status(struct chp_id chpid)
71 return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
74 /**
75 * chp_get_sch_opm - return opm for subchannel
76 * @sch: subchannel
78 * Calculate and return the operational path mask (opm) based on the chpids
79 * used by the subchannel and the status of the associated channel-paths.
81 u8 chp_get_sch_opm(struct subchannel *sch)
83 struct chp_id chpid;
84 int opm;
85 int i;
87 opm = 0;
88 chp_id_init(&chpid);
89 for (i=0; i < 8; i++) {
90 opm <<= 1;
91 chpid.id = sch->schib.pmcw.chpid[i];
92 if (chp_get_status(chpid) != 0)
93 opm |= 1;
95 return opm;
98 /**
99 * chp_is_registered - check if a channel-path is registered
100 * @chpid: channel-path ID
102 * Return non-zero if a channel-path with the given chpid is registered,
103 * zero otherwise.
105 int chp_is_registered(struct chp_id chpid)
107 return chpid_to_chp(chpid) != NULL;
111 * Function: s390_vary_chpid
112 * Varies the specified chpid online or offline
114 static int s390_vary_chpid(struct chp_id chpid, int on)
116 char dbf_text[15];
117 int status;
119 sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
120 chpid.id);
121 CIO_TRACE_EVENT( 2, dbf_text);
123 status = chp_get_status(chpid);
124 if (status < 0) {
125 printk(KERN_ERR "Can't vary unknown chpid %x.%02x\n",
126 chpid.cssid, chpid.id);
127 return -EINVAL;
130 if (!on && !status) {
131 printk(KERN_ERR "chpid %x.%02x is already offline\n",
132 chpid.cssid, chpid.id);
133 return -EINVAL;
136 set_chp_logically_online(chpid, on);
137 chsc_chp_vary(chpid, on);
138 return 0;
142 * Channel measurement related functions
144 static ssize_t chp_measurement_chars_read(struct kobject *kobj, char *buf,
145 loff_t off, size_t count)
147 struct channel_path *chp;
148 unsigned int size;
150 chp = to_channelpath(container_of(kobj, struct device, kobj));
151 if (!chp->cmg_chars)
152 return 0;
154 size = sizeof(struct cmg_chars);
156 if (off > size)
157 return 0;
158 if (off + count > size)
159 count = size - off;
160 memcpy(buf, chp->cmg_chars + off, count);
161 return count;
164 static struct bin_attribute chp_measurement_chars_attr = {
165 .attr = {
166 .name = "measurement_chars",
167 .mode = S_IRUSR,
168 .owner = THIS_MODULE,
170 .size = sizeof(struct cmg_chars),
171 .read = chp_measurement_chars_read,
174 static void chp_measurement_copy_block(struct cmg_entry *buf,
175 struct channel_subsystem *css,
176 struct chp_id chpid)
178 void *area;
179 struct cmg_entry *entry, reference_buf;
180 int idx;
182 if (chpid.id < 128) {
183 area = css->cub_addr1;
184 idx = chpid.id;
185 } else {
186 area = css->cub_addr2;
187 idx = chpid.id - 128;
189 entry = area + (idx * sizeof(struct cmg_entry));
190 do {
191 memcpy(buf, entry, sizeof(*entry));
192 memcpy(&reference_buf, entry, sizeof(*entry));
193 } while (reference_buf.values[0] != buf->values[0]);
196 static ssize_t chp_measurement_read(struct kobject *kobj, char *buf,
197 loff_t off, size_t count)
199 struct channel_path *chp;
200 struct channel_subsystem *css;
201 unsigned int size;
203 chp = to_channelpath(container_of(kobj, struct device, kobj));
204 css = to_css(chp->dev.parent);
206 size = sizeof(struct cmg_entry);
208 /* Only allow single reads. */
209 if (off || count < size)
210 return 0;
211 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
212 count = size;
213 return count;
216 static struct bin_attribute chp_measurement_attr = {
217 .attr = {
218 .name = "measurement",
219 .mode = S_IRUSR,
220 .owner = THIS_MODULE,
222 .size = sizeof(struct cmg_entry),
223 .read = chp_measurement_read,
226 void chp_remove_cmg_attr(struct channel_path *chp)
228 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
229 device_remove_bin_file(&chp->dev, &chp_measurement_attr);
232 int chp_add_cmg_attr(struct channel_path *chp)
234 int ret;
236 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
237 if (ret)
238 return ret;
239 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
240 if (ret)
241 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
242 return ret;
246 * Files for the channel path entries.
248 static ssize_t chp_status_show(struct device *dev,
249 struct device_attribute *attr, char *buf)
251 struct channel_path *chp = container_of(dev, struct channel_path, dev);
253 if (!chp)
254 return 0;
255 return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") :
256 sprintf(buf, "offline\n"));
259 static ssize_t chp_status_write(struct device *dev,
260 struct device_attribute *attr,
261 const char *buf, size_t count)
263 struct channel_path *cp = container_of(dev, struct channel_path, dev);
264 char cmd[10];
265 int num_args;
266 int error;
268 num_args = sscanf(buf, "%5s", cmd);
269 if (!num_args)
270 return count;
272 if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1"))
273 error = s390_vary_chpid(cp->chpid, 1);
274 else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0"))
275 error = s390_vary_chpid(cp->chpid, 0);
276 else
277 error = -EINVAL;
279 return error < 0 ? error : count;
283 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
285 static ssize_t chp_configure_show(struct device *dev,
286 struct device_attribute *attr, char *buf)
288 struct channel_path *cp;
289 int status;
291 cp = container_of(dev, struct channel_path, dev);
292 status = chp_info_get_status(cp->chpid);
293 if (status < 0)
294 return status;
296 return snprintf(buf, PAGE_SIZE, "%d\n", status);
299 static int cfg_wait_idle(void);
301 static ssize_t chp_configure_write(struct device *dev,
302 struct device_attribute *attr,
303 const char *buf, size_t count)
305 struct channel_path *cp;
306 int val;
307 char delim;
309 if (sscanf(buf, "%d %c", &val, &delim) != 1)
310 return -EINVAL;
311 if (val != 0 && val != 1)
312 return -EINVAL;
313 cp = container_of(dev, struct channel_path, dev);
314 chp_cfg_schedule(cp->chpid, val);
315 cfg_wait_idle();
317 return count;
320 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
322 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
323 char *buf)
325 struct channel_path *chp = container_of(dev, struct channel_path, dev);
327 if (!chp)
328 return 0;
329 return sprintf(buf, "%x\n", chp->desc.desc);
332 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
334 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
335 char *buf)
337 struct channel_path *chp = to_channelpath(dev);
339 if (!chp)
340 return 0;
341 if (chp->cmg == -1) /* channel measurements not available */
342 return sprintf(buf, "unknown\n");
343 return sprintf(buf, "%x\n", chp->cmg);
346 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
348 static ssize_t chp_shared_show(struct device *dev,
349 struct device_attribute *attr, char *buf)
351 struct channel_path *chp = to_channelpath(dev);
353 if (!chp)
354 return 0;
355 if (chp->shared == -1) /* channel measurements not available */
356 return sprintf(buf, "unknown\n");
357 return sprintf(buf, "%x\n", chp->shared);
360 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
362 static struct attribute * chp_attrs[] = {
363 &dev_attr_status.attr,
364 &dev_attr_configure.attr,
365 &dev_attr_type.attr,
366 &dev_attr_cmg.attr,
367 &dev_attr_shared.attr,
368 NULL,
371 static struct attribute_group chp_attr_group = {
372 .attrs = chp_attrs,
375 static void chp_release(struct device *dev)
377 struct channel_path *cp;
379 cp = container_of(dev, struct channel_path, dev);
380 kfree(cp);
384 * chp_new - register a new channel-path
385 * @chpid - channel-path ID
387 * Create and register data structure representing new channel-path. Return
388 * zero on success, non-zero otherwise.
390 int chp_new(struct chp_id chpid)
392 struct channel_path *chp;
393 int ret;
395 if (chp_is_registered(chpid))
396 return 0;
397 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
398 if (!chp)
399 return -ENOMEM;
401 /* fill in status, etc. */
402 chp->chpid = chpid;
403 chp->state = 1;
404 chp->dev.parent = &css[chpid.cssid]->device;
405 chp->dev.release = chp_release;
406 snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp%x.%02x", chpid.cssid,
407 chpid.id);
409 /* Obtain channel path description and fill it in. */
410 ret = chsc_determine_channel_path_description(chpid, &chp->desc);
411 if (ret)
412 goto out_free;
413 if ((chp->desc.flags & 0x80) == 0) {
414 ret = -ENODEV;
415 goto out_free;
417 /* Get channel-measurement characteristics. */
418 if (css_characteristics_avail && css_chsc_characteristics.scmc
419 && css_chsc_characteristics.secm) {
420 ret = chsc_get_channel_measurement_chars(chp);
421 if (ret)
422 goto out_free;
423 } else {
424 static int msg_done;
426 if (!msg_done) {
427 printk(KERN_WARNING "cio: Channel measurements not "
428 "available, continuing.\n");
429 msg_done = 1;
431 chp->cmg = -1;
434 /* make it known to the system */
435 ret = device_register(&chp->dev);
436 if (ret) {
437 printk(KERN_WARNING "%s: could not register %x.%02x\n",
438 __func__, chpid.cssid, chpid.id);
439 goto out_free;
441 ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
442 if (ret) {
443 device_unregister(&chp->dev);
444 goto out_free;
446 mutex_lock(&css[chpid.cssid]->mutex);
447 if (css[chpid.cssid]->cm_enabled) {
448 ret = chp_add_cmg_attr(chp);
449 if (ret) {
450 sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
451 device_unregister(&chp->dev);
452 mutex_unlock(&css[chpid.cssid]->mutex);
453 goto out_free;
456 css[chpid.cssid]->chps[chpid.id] = chp;
457 mutex_unlock(&css[chpid.cssid]->mutex);
458 return ret;
459 out_free:
460 kfree(chp);
461 return ret;
465 * chp_get_chp_desc - return newly allocated channel-path description
466 * @chpid: channel-path ID
468 * On success return a newly allocated copy of the channel-path description
469 * data associated with the given channel-path ID. Return %NULL on error.
471 void *chp_get_chp_desc(struct chp_id chpid)
473 struct channel_path *chp;
474 struct channel_path_desc *desc;
476 chp = chpid_to_chp(chpid);
477 if (!chp)
478 return NULL;
479 desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
480 if (!desc)
481 return NULL;
482 memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
483 return desc;
487 * chp_process_crw - process channel-path status change
488 * @id: channel-path ID number
489 * @status: non-zero if channel-path has become available, zero otherwise
491 * Handle channel-report-words indicating that the status of a channel-path
492 * has changed.
494 void chp_process_crw(int id, int status)
496 struct chp_id chpid;
498 chp_id_init(&chpid);
499 chpid.id = id;
500 if (status) {
501 if (!chp_is_registered(chpid))
502 chp_new(chpid);
503 chsc_chp_online(chpid);
504 } else
505 chsc_chp_offline(chpid);
508 static inline int info_bit_num(struct chp_id id)
510 return id.id + id.cssid * (__MAX_CHPID + 1);
513 /* Force chp_info refresh on next call to info_validate(). */
514 static void info_expire(void)
516 mutex_lock(&info_lock);
517 chp_info_expires = jiffies - 1;
518 mutex_unlock(&info_lock);
521 /* Ensure that chp_info is up-to-date. */
522 static int info_update(void)
524 int rc;
526 mutex_lock(&info_lock);
527 rc = 0;
528 if (time_after(jiffies, chp_info_expires)) {
529 /* Data is too old, update. */
530 rc = sclp_chp_read_info(&chp_info);
531 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
533 mutex_unlock(&info_lock);
535 return rc;
539 * chp_info_get_status - retrieve configure status of a channel-path
540 * @chpid: channel-path ID
542 * On success, return 0 for standby, 1 for configured, 2 for reserved,
543 * 3 for not recognized. Return negative error code on error.
545 int chp_info_get_status(struct chp_id chpid)
547 int rc;
548 int bit;
550 rc = info_update();
551 if (rc)
552 return rc;
554 bit = info_bit_num(chpid);
555 mutex_lock(&info_lock);
556 if (!chp_test_bit(chp_info.recognized, bit))
557 rc = CHP_STATUS_NOT_RECOGNIZED;
558 else if (chp_test_bit(chp_info.configured, bit))
559 rc = CHP_STATUS_CONFIGURED;
560 else if (chp_test_bit(chp_info.standby, bit))
561 rc = CHP_STATUS_STANDBY;
562 else
563 rc = CHP_STATUS_RESERVED;
564 mutex_unlock(&info_lock);
566 return rc;
569 /* Return configure task for chpid. */
570 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
572 return chp_cfg_task[chpid.cssid][chpid.id];
575 /* Set configure task for chpid. */
576 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
578 chp_cfg_task[chpid.cssid][chpid.id] = cfg;
581 /* Perform one configure/deconfigure request. Reschedule work function until
582 * last request. */
583 static void cfg_func(struct work_struct *work)
585 struct chp_id chpid;
586 enum cfg_task_t t;
588 mutex_lock(&cfg_lock);
589 t = cfg_none;
590 chp_id_for_each(&chpid) {
591 t = cfg_get_task(chpid);
592 if (t != cfg_none) {
593 cfg_set_task(chpid, cfg_none);
594 break;
597 mutex_unlock(&cfg_lock);
599 switch (t) {
600 case cfg_configure:
601 sclp_chp_configure(chpid);
602 info_expire();
603 chsc_chp_online(chpid);
604 break;
605 case cfg_deconfigure:
606 sclp_chp_deconfigure(chpid);
607 info_expire();
608 chsc_chp_offline(chpid);
609 break;
610 case cfg_none:
611 /* Get updated information after last change. */
612 info_update();
613 mutex_lock(&cfg_lock);
614 cfg_busy = 0;
615 mutex_unlock(&cfg_lock);
616 wake_up_interruptible(&cfg_wait_queue);
617 return;
619 queue_work(chp_wq, &cfg_work);
623 * chp_cfg_schedule - schedule chpid configuration request
624 * @chpid - channel-path ID
625 * @configure - Non-zero for configure, zero for deconfigure
627 * Schedule a channel-path configuration/deconfiguration request.
629 void chp_cfg_schedule(struct chp_id chpid, int configure)
631 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
632 configure);
633 mutex_lock(&cfg_lock);
634 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
635 cfg_busy = 1;
636 mutex_unlock(&cfg_lock);
637 queue_work(chp_wq, &cfg_work);
641 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
642 * @chpid - channel-path ID
644 * Cancel an active channel-path deconfiguration request if it has not yet
645 * been performed.
647 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
649 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
650 mutex_lock(&cfg_lock);
651 if (cfg_get_task(chpid) == cfg_deconfigure)
652 cfg_set_task(chpid, cfg_none);
653 mutex_unlock(&cfg_lock);
656 static int cfg_wait_idle(void)
658 if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
659 return -ERESTARTSYS;
660 return 0;
663 static int __init chp_init(void)
665 struct chp_id chpid;
667 chp_wq = create_singlethread_workqueue("cio_chp");
668 if (!chp_wq)
669 return -ENOMEM;
670 INIT_WORK(&cfg_work, cfg_func);
671 init_waitqueue_head(&cfg_wait_queue);
672 if (info_update())
673 return 0;
674 /* Register available channel-paths. */
675 chp_id_for_each(&chpid) {
676 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
677 chp_new(chpid);
680 return 0;
683 subsys_initcall(chp_init);