Merge branch 'linux-2.6'
[linux-2.6] / drivers / s390 / cio / chsc.c
1 /*
2  *  drivers/s390/cio/chsc.c
3  *   S/390 common I/O routines -- channel subsystem call
4  *
5  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
6  *                            IBM Corporation
7  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
9  *               Arnd Bergmann (arndb@de.ibm.com)
10  */
11
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/device.h>
16
17 #include <asm/cio.h>
18
19 #include "css.h"
20 #include "cio.h"
21 #include "cio_debug.h"
22 #include "ioasm.h"
23 #include "chsc.h"
24
25 static void *sei_page;
26
27 static int new_channel_path(int chpid);
28
29 static inline void
30 set_chp_logically_online(int chp, int onoff)
31 {
32         css[0]->chps[chp]->state = onoff;
33 }
34
35 static int
36 get_chp_status(int chp)
37 {
38         return (css[0]->chps[chp] ? css[0]->chps[chp]->state : -ENODEV);
39 }
40
41 void
42 chsc_validate_chpids(struct subchannel *sch)
43 {
44         int mask, chp;
45
46         for (chp = 0; chp <= 7; chp++) {
47                 mask = 0x80 >> chp;
48                 if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
49                         /* disable using this path */
50                         sch->opm &= ~mask;
51         }
52 }
53
54 void
55 chpid_is_actually_online(int chp)
56 {
57         int state;
58
59         state = get_chp_status(chp);
60         if (state < 0) {
61                 need_rescan = 1;
62                 queue_work(slow_path_wq, &slow_path_work);
63         } else
64                 WARN_ON(!state);
65 }
66
67 /* FIXME: this is _always_ called for every subchannel. shouldn't we
68  *        process more than one at a time? */
69 static int
70 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
71 {
72         int ccode, j;
73
74         struct {
75                 struct chsc_header request;
76                 u16 reserved1a:10;
77                 u16 ssid:2;
78                 u16 reserved1b:4;
79                 u16 f_sch;        /* first subchannel */
80                 u16 reserved2;
81                 u16 l_sch;        /* last subchannel */
82                 u32 reserved3;
83                 struct chsc_header response;
84                 u32 reserved4;
85                 u8 sch_valid : 1;
86                 u8 dev_valid : 1;
87                 u8 st        : 3; /* subchannel type */
88                 u8 zeroes    : 3;
89                 u8  unit_addr;    /* unit address */
90                 u16 devno;        /* device number */
91                 u8 path_mask;
92                 u8 fla_valid_mask;
93                 u16 sch;          /* subchannel */
94                 u8 chpid[8];      /* chpids 0-7 */
95                 u16 fla[8];       /* full link addresses 0-7 */
96         } *ssd_area;
97
98         ssd_area = page;
99
100         ssd_area->request.length = 0x0010;
101         ssd_area->request.code = 0x0004;
102
103         ssd_area->ssid = sch->schid.ssid;
104         ssd_area->f_sch = sch->schid.sch_no;
105         ssd_area->l_sch = sch->schid.sch_no;
106
107         ccode = chsc(ssd_area);
108         if (ccode > 0) {
109                 pr_debug("chsc returned with ccode = %d\n", ccode);
110                 return (ccode == 3) ? -ENODEV : -EBUSY;
111         }
112
113         switch (ssd_area->response.code) {
114         case 0x0001: /* everything ok */
115                 break;
116         case 0x0002:
117                 CIO_CRW_EVENT(2, "Invalid command!\n");
118                 return -EINVAL;
119         case 0x0003:
120                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
121                 return -EINVAL;
122         case 0x0004:
123                 CIO_CRW_EVENT(2, "Model does not provide ssd\n");
124                 return -EOPNOTSUPP;
125         default:
126                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
127                               ssd_area->response.code);
128                 return -EIO;
129         }
130
131         /*
132          * ssd_area->st stores the type of the detected
133          * subchannel, with the following definitions:
134          *
135          * 0: I/O subchannel:     All fields have meaning
136          * 1: CHSC subchannel:    Only sch_val, st and sch
137          *                        have meaning
138          * 2: Message subchannel: All fields except unit_addr
139          *                        have meaning
140          * 3: ADM subchannel:     Only sch_val, st and sch
141          *                        have meaning
142          *
143          * Other types are currently undefined.
144          */
145         if (ssd_area->st > 3) { /* uhm, that looks strange... */
146                 CIO_CRW_EVENT(0, "Strange subchannel type %d"
147                               " for sch 0.%x.%04x\n", ssd_area->st,
148                               sch->schid.ssid, sch->schid.sch_no);
149                 /*
150                  * There may have been a new subchannel type defined in the
151                  * time since this code was written; since we don't know which
152                  * fields have meaning and what to do with it we just jump out
153                  */
154                 return 0;
155         } else {
156                 const char *type[4] = {"I/O", "chsc", "message", "ADM"};
157                 CIO_CRW_EVENT(6, "ssd: sch 0.%x.%04x is %s subchannel\n",
158                               sch->schid.ssid, sch->schid.sch_no,
159                               type[ssd_area->st]);
160
161                 sch->ssd_info.valid = 1;
162                 sch->ssd_info.type = ssd_area->st;
163         }
164
165         if (ssd_area->st == 0 || ssd_area->st == 2) {
166                 for (j = 0; j < 8; j++) {
167                         if (!((0x80 >> j) & ssd_area->path_mask &
168                               ssd_area->fla_valid_mask))
169                                 continue;
170                         sch->ssd_info.chpid[j] = ssd_area->chpid[j];
171                         sch->ssd_info.fla[j]   = ssd_area->fla[j];
172                 }
173         }
174         return 0;
175 }
176
177 int
178 css_get_ssd_info(struct subchannel *sch)
179 {
180         int ret;
181         void *page;
182
183         page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
184         if (!page)
185                 return -ENOMEM;
186         spin_lock_irq(&sch->lock);
187         ret = chsc_get_sch_desc_irq(sch, page);
188         if (ret) {
189                 static int cio_chsc_err_msg;
190                 
191                 if (!cio_chsc_err_msg) {
192                         printk(KERN_ERR
193                                "chsc_get_sch_descriptions:"
194                                " Error %d while doing chsc; "
195                                "processing some machine checks may "
196                                "not work\n", ret);
197                         cio_chsc_err_msg = 1;
198                 }
199         }
200         spin_unlock_irq(&sch->lock);
201         free_page((unsigned long)page);
202         if (!ret) {
203                 int j, chpid;
204                 /* Allocate channel path structures, if needed. */
205                 for (j = 0; j < 8; j++) {
206                         chpid = sch->ssd_info.chpid[j];
207                         if (chpid && (get_chp_status(chpid) < 0))
208                             new_channel_path(chpid);
209                 }
210         }
211         return ret;
212 }
213
214 static int
215 s390_subchannel_remove_chpid(struct device *dev, void *data)
216 {
217         int j;
218         int mask;
219         struct subchannel *sch;
220         struct channel_path *chpid;
221         struct schib schib;
222
223         sch = to_subchannel(dev);
224         chpid = data;
225         for (j = 0; j < 8; j++)
226                 if (sch->schib.pmcw.chpid[j] == chpid->id)
227                         break;
228         if (j >= 8)
229                 return 0;
230
231         mask = 0x80 >> j;
232         spin_lock_irq(&sch->lock);
233
234         stsch(sch->schid, &schib);
235         if (!schib.pmcw.dnv)
236                 goto out_unreg;
237         memcpy(&sch->schib, &schib, sizeof(struct schib));
238         /* Check for single path devices. */
239         if (sch->schib.pmcw.pim == 0x80)
240                 goto out_unreg;
241
242         if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
243             (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
244             (sch->schib.pmcw.lpum == mask)) {
245                 int cc;
246
247                 cc = cio_clear(sch);
248                 if (cc == -ENODEV)
249                         goto out_unreg;
250                 /* Call handler. */
251                 if (sch->driver && sch->driver->termination)
252                         sch->driver->termination(&sch->dev);
253                 goto out_unlock;
254         }
255
256         /* trigger path verification. */
257         if (sch->driver && sch->driver->verify)
258                 sch->driver->verify(&sch->dev);
259         else if (sch->vpm == mask)
260                 goto out_unreg;
261 out_unlock:
262         spin_unlock_irq(&sch->lock);
263         return 0;
264 out_unreg:
265         spin_unlock_irq(&sch->lock);
266         sch->lpm = 0;
267         if (css_enqueue_subchannel_slow(sch->schid)) {
268                 css_clear_subchannel_slow_list();
269                 need_rescan = 1;
270         }
271         return 0;
272 }
273
274 static inline void
275 s390_set_chpid_offline( __u8 chpid)
276 {
277         char dbf_txt[15];
278         struct device *dev;
279
280         sprintf(dbf_txt, "chpr%x", chpid);
281         CIO_TRACE_EVENT(2, dbf_txt);
282
283         if (get_chp_status(chpid) <= 0)
284                 return;
285         dev = get_device(&css[0]->chps[chpid]->dev);
286         bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
287                          s390_subchannel_remove_chpid);
288
289         if (need_rescan || css_slow_subchannels_exist())
290                 queue_work(slow_path_wq, &slow_path_work);
291         put_device(dev);
292 }
293
294 struct res_acc_data {
295         struct channel_path *chp;
296         u32 fla_mask;
297         u16 fla;
298 };
299
300 static int
301 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
302 {
303         int found;
304         int chp;
305         int ccode;
306         
307         found = 0;
308         for (chp = 0; chp <= 7; chp++)
309                 /*
310                  * check if chpid is in information updated by ssd
311                  */
312                 if (sch->ssd_info.valid &&
313                     sch->ssd_info.chpid[chp] == res_data->chp->id &&
314                     (sch->ssd_info.fla[chp] & res_data->fla_mask)
315                     == res_data->fla) {
316                         found = 1;
317                         break;
318                 }
319         
320         if (found == 0)
321                 return 0;
322
323         /*
324          * Do a stsch to update our subchannel structure with the
325          * new path information and eventually check for logically
326          * offline chpids.
327          */
328         ccode = stsch(sch->schid, &sch->schib);
329         if (ccode > 0)
330                 return 0;
331
332         return 0x80 >> chp;
333 }
334
335 static inline int
336 s390_process_res_acc_new_sch(struct subchannel_id schid)
337 {
338         struct schib schib;
339         int ret;
340         /*
341          * We don't know the device yet, but since a path
342          * may be available now to the device we'll have
343          * to do recognition again.
344          * Since we don't have any idea about which chpid
345          * that beast may be on we'll have to do a stsch
346          * on all devices, grr...
347          */
348         if (stsch_err(schid, &schib))
349                 /* We're through */
350                 return need_rescan ? -EAGAIN : -ENXIO;
351
352         /* Put it on the slow path. */
353         ret = css_enqueue_subchannel_slow(schid);
354         if (ret) {
355                 css_clear_subchannel_slow_list();
356                 need_rescan = 1;
357                 return -EAGAIN;
358         }
359         return 0;
360 }
361
362 static int
363 __s390_process_res_acc(struct subchannel_id schid, void *data)
364 {
365         int chp_mask, old_lpm;
366         struct res_acc_data *res_data;
367         struct subchannel *sch;
368
369         res_data = (struct res_acc_data *)data;
370         sch = get_subchannel_by_schid(schid);
371         if (!sch)
372                 /* Check if a subchannel is newly available. */
373                 return s390_process_res_acc_new_sch(schid);
374
375         spin_lock_irq(&sch->lock);
376
377         chp_mask = s390_process_res_acc_sch(res_data, sch);
378
379         if (chp_mask == 0) {
380                 spin_unlock_irq(&sch->lock);
381                 return 0;
382         }
383         old_lpm = sch->lpm;
384         sch->lpm = ((sch->schib.pmcw.pim &
385                      sch->schib.pmcw.pam &
386                      sch->schib.pmcw.pom)
387                     | chp_mask) & sch->opm;
388         if (!old_lpm && sch->lpm)
389                 device_trigger_reprobe(sch);
390         else if (sch->driver && sch->driver->verify)
391                 sch->driver->verify(&sch->dev);
392
393         spin_unlock_irq(&sch->lock);
394         put_device(&sch->dev);
395         return (res_data->fla_mask == 0xffff) ? -ENODEV : 0;
396 }
397
398
399 static int
400 s390_process_res_acc (struct res_acc_data *res_data)
401 {
402         int rc;
403         char dbf_txt[15];
404
405         sprintf(dbf_txt, "accpr%x", res_data->chp->id);
406         CIO_TRACE_EVENT( 2, dbf_txt);
407         if (res_data->fla != 0) {
408                 sprintf(dbf_txt, "fla%x", res_data->fla);
409                 CIO_TRACE_EVENT( 2, dbf_txt);
410         }
411
412         /*
413          * I/O resources may have become accessible.
414          * Scan through all subchannels that may be concerned and
415          * do a validation on those.
416          * The more information we have (info), the less scanning
417          * will we have to do.
418          */
419         rc = for_each_subchannel(__s390_process_res_acc, res_data);
420         if (css_slow_subchannels_exist())
421                 rc = -EAGAIN;
422         else if (rc != -EAGAIN)
423                 rc = 0;
424         return rc;
425 }
426
427 static int
428 __get_chpid_from_lir(void *data)
429 {
430         struct lir {
431                 u8  iq;
432                 u8  ic;
433                 u16 sci;
434                 /* incident-node descriptor */
435                 u32 indesc[28];
436                 /* attached-node descriptor */
437                 u32 andesc[28];
438                 /* incident-specific information */
439                 u32 isinfo[28];
440         } *lir;
441
442         lir = (struct lir*) data;
443         if (!(lir->iq&0x80))
444                 /* NULL link incident record */
445                 return -EINVAL;
446         if (!(lir->indesc[0]&0xc0000000))
447                 /* node descriptor not valid */
448                 return -EINVAL;
449         if (!(lir->indesc[0]&0x10000000))
450                 /* don't handle device-type nodes - FIXME */
451                 return -EINVAL;
452         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
453
454         return (u16) (lir->indesc[0]&0x000000ff);
455 }
456
457 int
458 chsc_process_crw(void)
459 {
460         int chpid, ret;
461         struct res_acc_data res_data;
462         struct {
463                 struct chsc_header request;
464                 u32 reserved1;
465                 u32 reserved2;
466                 u32 reserved3;
467                 struct chsc_header response;
468                 u32 reserved4;
469                 u8  flags;
470                 u8  vf;         /* validity flags */
471                 u8  rs;         /* reporting source */
472                 u8  cc;         /* content code */
473                 u16 fla;        /* full link address */
474                 u16 rsid;       /* reporting source id */
475                 u32 reserved5;
476                 u32 reserved6;
477                 u32 ccdf[96];   /* content-code dependent field */
478                 /* ccdf has to be big enough for a link-incident record */
479         } *sei_area;
480
481         if (!sei_page)
482                 return 0;
483         /*
484          * build the chsc request block for store event information
485          * and do the call
486          * This function is only called by the machine check handler thread,
487          * so we don't need locking for the sei_page.
488          */
489         sei_area = sei_page;
490
491         CIO_TRACE_EVENT( 2, "prcss");
492         ret = 0;
493         do {
494                 int ccode, status;
495                 struct device *dev;
496                 memset(sei_area, 0, sizeof(*sei_area));
497                 memset(&res_data, 0, sizeof(struct res_acc_data));
498                 sei_area->request.length = 0x0010;
499                 sei_area->request.code = 0x000e;
500
501                 ccode = chsc(sei_area);
502                 if (ccode > 0)
503                         return 0;
504
505                 switch (sei_area->response.code) {
506                         /* for debug purposes, check for problems */
507                 case 0x0001:
508                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
509                                         "successfully stored\n");
510                         break; /* everything ok */
511                 case 0x0002:
512                         CIO_CRW_EVENT(2,
513                                       "chsc_process_crw: invalid command!\n");
514                         return 0;
515                 case 0x0003:
516                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
517                                       "request block!\n");
518                         return 0;
519                 case 0x0005:
520                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
521                                       "information stored\n");
522                         return 0;
523                 default:
524                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
525                                       sei_area->response.code);
526                         return 0;
527                 }
528
529                 /* Check if we might have lost some information. */
530                 if (sei_area->flags & 0x40)
531                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
532                                        "has been lost due to overflow!\n");
533
534                 if (sei_area->rs != 4) {
535                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
536                                       "(%04X) isn't a chpid!\n",
537                                       sei_area->rsid);
538                         continue;
539                 }
540
541                 /* which kind of information was stored? */
542                 switch (sei_area->cc) {
543                 case 1: /* link incident*/
544                         CIO_CRW_EVENT(4, "chsc_process_crw: "
545                                       "channel subsystem reports link incident,"
546                                       " reporting source is chpid %x\n",
547                                       sei_area->rsid);
548                         chpid = __get_chpid_from_lir(sei_area->ccdf);
549                         if (chpid < 0)
550                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
551                                               __FUNCTION__);
552                         else
553                                 s390_set_chpid_offline(chpid);
554                         break;
555                         
556                 case 2: /* i/o resource accessibiliy */
557                         CIO_CRW_EVENT(4, "chsc_process_crw: "
558                                       "channel subsystem reports some I/O "
559                                       "devices may have become accessible\n");
560                         pr_debug("Data received after sei: \n");
561                         pr_debug("Validity flags: %x\n", sei_area->vf);
562                         
563                         /* allocate a new channel path structure, if needed */
564                         status = get_chp_status(sei_area->rsid);
565                         if (status < 0)
566                                 new_channel_path(sei_area->rsid);
567                         else if (!status)
568                                 break;
569                         dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
570                         res_data.chp = to_channelpath(dev);
571                         pr_debug("chpid: %x", sei_area->rsid);
572                         if ((sei_area->vf & 0xc0) != 0) {
573                                 res_data.fla = sei_area->fla;
574                                 if ((sei_area->vf & 0xc0) == 0xc0) {
575                                         pr_debug(" full link addr: %x",
576                                                  sei_area->fla);
577                                         res_data.fla_mask = 0xffff;
578                                 } else {
579                                         pr_debug(" link addr: %x",
580                                                  sei_area->fla);
581                                         res_data.fla_mask = 0xff00;
582                                 }
583                         }
584                         ret = s390_process_res_acc(&res_data);
585                         pr_debug("\n\n");
586                         put_device(dev);
587                         break;
588                         
589                 default: /* other stuff */
590                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
591                                       sei_area->cc);
592                         break;
593                 }
594         } while (sei_area->flags & 0x80);
595         return ret;
596 }
597
598 static inline int
599 __chp_add_new_sch(struct subchannel_id schid)
600 {
601         struct schib schib;
602         int ret;
603
604         if (stsch(schid, &schib))
605                 /* We're through */
606                 return need_rescan ? -EAGAIN : -ENXIO;
607
608         /* Put it on the slow path. */
609         ret = css_enqueue_subchannel_slow(schid);
610         if (ret) {
611                 css_clear_subchannel_slow_list();
612                 need_rescan = 1;
613                 return -EAGAIN;
614         }
615         return 0;
616 }
617
618
619 static int
620 __chp_add(struct subchannel_id schid, void *data)
621 {
622         int i;
623         struct channel_path *chp;
624         struct subchannel *sch;
625
626         chp = (struct channel_path *)data;
627         sch = get_subchannel_by_schid(schid);
628         if (!sch)
629                 /* Check if the subchannel is now available. */
630                 return __chp_add_new_sch(schid);
631         spin_lock_irq(&sch->lock);
632         for (i=0; i<8; i++)
633                 if (sch->schib.pmcw.chpid[i] == chp->id) {
634                         if (stsch(sch->schid, &sch->schib) != 0) {
635                                 /* Endgame. */
636                                 spin_unlock_irq(&sch->lock);
637                                 return -ENXIO;
638                         }
639                         break;
640                 }
641         if (i==8) {
642                 spin_unlock_irq(&sch->lock);
643                 return 0;
644         }
645         sch->lpm = ((sch->schib.pmcw.pim &
646                      sch->schib.pmcw.pam &
647                      sch->schib.pmcw.pom)
648                     | 0x80 >> i) & sch->opm;
649
650         if (sch->driver && sch->driver->verify)
651                 sch->driver->verify(&sch->dev);
652
653         spin_unlock_irq(&sch->lock);
654         put_device(&sch->dev);
655         return 0;
656 }
657
658 static int
659 chp_add(int chpid)
660 {
661         int rc;
662         char dbf_txt[15];
663         struct device *dev;
664
665         if (!get_chp_status(chpid))
666                 return 0; /* no need to do the rest */
667         
668         sprintf(dbf_txt, "cadd%x", chpid);
669         CIO_TRACE_EVENT(2, dbf_txt);
670
671         dev = get_device(&css[0]->chps[chpid]->dev);
672         rc = for_each_subchannel(__chp_add, to_channelpath(dev));
673         if (css_slow_subchannels_exist())
674                 rc = -EAGAIN;
675         if (rc != -EAGAIN)
676                 rc = 0;
677         put_device(dev);
678         return rc;
679 }
680
681 /* 
682  * Handling of crw machine checks with channel path source.
683  */
684 int
685 chp_process_crw(int chpid, int on)
686 {
687         if (on == 0) {
688                 /* Path has gone. We use the link incident routine.*/
689                 s390_set_chpid_offline(chpid);
690                 return 0; /* De-register is async anyway. */
691         }
692         /*
693          * Path has come. Allocate a new channel path structure,
694          * if needed.
695          */
696         if (get_chp_status(chpid) < 0)
697                 new_channel_path(chpid);
698         /* Avoid the extra overhead in process_rec_acc. */
699         return chp_add(chpid);
700 }
701
702 static inline int
703 __check_for_io_and_kill(struct subchannel *sch, int index)
704 {
705         int cc;
706
707         if (!device_is_online(sch))
708                 /* cio could be doing I/O. */
709                 return 0;
710         cc = stsch(sch->schid, &sch->schib);
711         if (cc)
712                 return 0;
713         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
714                 device_set_waiting(sch);
715                 return 1;
716         }
717         return 0;
718 }
719
720 static inline void
721 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
722 {
723         int chp, old_lpm;
724         unsigned long flags;
725
726         if (!sch->ssd_info.valid)
727                 return;
728         
729         spin_lock_irqsave(&sch->lock, flags);
730         old_lpm = sch->lpm;
731         for (chp = 0; chp < 8; chp++) {
732                 if (sch->ssd_info.chpid[chp] != chpid)
733                         continue;
734
735                 if (on) {
736                         sch->opm |= (0x80 >> chp);
737                         sch->lpm |= (0x80 >> chp);
738                         if (!old_lpm)
739                                 device_trigger_reprobe(sch);
740                         else if (sch->driver && sch->driver->verify)
741                                 sch->driver->verify(&sch->dev);
742                 } else {
743                         sch->opm &= ~(0x80 >> chp);
744                         sch->lpm &= ~(0x80 >> chp);
745                         /*
746                          * Give running I/O a grace period in which it
747                          * can successfully terminate, even using the
748                          * just varied off path. Then kill it.
749                          */
750                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
751                                 if (css_enqueue_subchannel_slow(sch->schid)) {
752                                         css_clear_subchannel_slow_list();
753                                         need_rescan = 1;
754                                 }
755                         } else if (sch->driver && sch->driver->verify)
756                                 sch->driver->verify(&sch->dev);
757                 }
758                 break;
759         }
760         spin_unlock_irqrestore(&sch->lock, flags);
761 }
762
763 static int
764 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
765 {
766         struct subchannel *sch;
767         __u8 *chpid;
768
769         sch = to_subchannel(dev);
770         chpid = data;
771
772         __s390_subchannel_vary_chpid(sch, *chpid, 0);
773         return 0;
774 }
775
776 static int
777 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
778 {
779         struct subchannel *sch;
780         __u8 *chpid;
781
782         sch = to_subchannel(dev);
783         chpid = data;
784
785         __s390_subchannel_vary_chpid(sch, *chpid, 1);
786         return 0;
787 }
788
789 static int
790 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
791 {
792         struct schib schib;
793         struct subchannel *sch;
794
795         sch = get_subchannel_by_schid(schid);
796         if (sch) {
797                 put_device(&sch->dev);
798                 return 0;
799         }
800         if (stsch_err(schid, &schib))
801                 /* We're through */
802                 return -ENXIO;
803         /* Put it on the slow path. */
804         if (css_enqueue_subchannel_slow(schid)) {
805                 css_clear_subchannel_slow_list();
806                 need_rescan = 1;
807                 return -EAGAIN;
808         }
809         return 0;
810 }
811
812 /*
813  * Function: s390_vary_chpid
814  * Varies the specified chpid online or offline
815  */
816 static int
817 s390_vary_chpid( __u8 chpid, int on)
818 {
819         char dbf_text[15];
820         int status;
821
822         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
823         CIO_TRACE_EVENT( 2, dbf_text);
824
825         status = get_chp_status(chpid);
826         if (status < 0) {
827                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
828                 return -EINVAL;
829         }
830
831         if (!on && !status) {
832                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
833                 return -EINVAL;
834         }
835
836         set_chp_logically_online(chpid, on);
837
838         /*
839          * Redo PathVerification on the devices the chpid connects to
840          */
841
842         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
843                          s390_subchannel_vary_chpid_on :
844                          s390_subchannel_vary_chpid_off);
845         if (on)
846                 /* Scan for new devices on varied on path. */
847                 for_each_subchannel(__s390_vary_chpid_on, NULL);
848         if (need_rescan || css_slow_subchannels_exist())
849                 queue_work(slow_path_wq, &slow_path_work);
850         return 0;
851 }
852
853 /*
854  * Channel measurement related functions
855  */
856 static ssize_t
857 chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
858                            size_t count)
859 {
860         struct channel_path *chp;
861         unsigned int size;
862
863         chp = to_channelpath(container_of(kobj, struct device, kobj));
864         if (!chp->cmg_chars)
865                 return 0;
866
867         size = sizeof(struct cmg_chars);
868
869         if (off > size)
870                 return 0;
871         if (off + count > size)
872                 count = size - off;
873         memcpy(buf, chp->cmg_chars + off, count);
874         return count;
875 }
876
877 static struct bin_attribute chp_measurement_chars_attr = {
878         .attr = {
879                 .name = "measurement_chars",
880                 .mode = S_IRUSR,
881                 .owner = THIS_MODULE,
882         },
883         .size = sizeof(struct cmg_chars),
884         .read = chp_measurement_chars_read,
885 };
886
887 static void
888 chp_measurement_copy_block(struct cmg_entry *buf,
889                            struct channel_subsystem *css, int chpid)
890 {
891         void *area;
892         struct cmg_entry *entry, reference_buf;
893         int idx;
894
895         if (chpid < 128) {
896                 area = css->cub_addr1;
897                 idx = chpid;
898         } else {
899                 area = css->cub_addr2;
900                 idx = chpid - 128;
901         }
902         entry = area + (idx * sizeof(struct cmg_entry));
903         do {
904                 memcpy(buf, entry, sizeof(*entry));
905                 memcpy(&reference_buf, entry, sizeof(*entry));
906         } while (reference_buf.values[0] != buf->values[0]);
907 }
908
909 static ssize_t
910 chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
911 {
912         struct channel_path *chp;
913         struct channel_subsystem *css;
914         unsigned int size;
915
916         chp = to_channelpath(container_of(kobj, struct device, kobj));
917         css = to_css(chp->dev.parent);
918
919         size = sizeof(struct cmg_entry);
920
921         /* Only allow single reads. */
922         if (off || count < size)
923                 return 0;
924         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
925         count = size;
926         return count;
927 }
928
929 static struct bin_attribute chp_measurement_attr = {
930         .attr = {
931                 .name = "measurement",
932                 .mode = S_IRUSR,
933                 .owner = THIS_MODULE,
934         },
935         .size = sizeof(struct cmg_entry),
936         .read = chp_measurement_read,
937 };
938
939 static void
940 chsc_remove_chp_cmg_attr(struct channel_path *chp)
941 {
942         sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
943         sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
944 }
945
946 static int
947 chsc_add_chp_cmg_attr(struct channel_path *chp)
948 {
949         int ret;
950
951         ret = sysfs_create_bin_file(&chp->dev.kobj,
952                                     &chp_measurement_chars_attr);
953         if (ret)
954                 return ret;
955         ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
956         if (ret)
957                 sysfs_remove_bin_file(&chp->dev.kobj,
958                                       &chp_measurement_chars_attr);
959         return ret;
960 }
961
962 static void
963 chsc_remove_cmg_attr(struct channel_subsystem *css)
964 {
965         int i;
966
967         for (i = 0; i <= __MAX_CHPID; i++) {
968                 if (!css->chps[i])
969                         continue;
970                 chsc_remove_chp_cmg_attr(css->chps[i]);
971         }
972 }
973
974 static int
975 chsc_add_cmg_attr(struct channel_subsystem *css)
976 {
977         int i, ret;
978
979         ret = 0;
980         for (i = 0; i <= __MAX_CHPID; i++) {
981                 if (!css->chps[i])
982                         continue;
983                 ret = chsc_add_chp_cmg_attr(css->chps[i]);
984                 if (ret)
985                         goto cleanup;
986         }
987         return ret;
988 cleanup:
989         for (--i; i >= 0; i--) {
990                 if (!css->chps[i])
991                         continue;
992                 chsc_remove_chp_cmg_attr(css->chps[i]);
993         }
994         return ret;
995 }
996
997
998 static int
999 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1000 {
1001         struct {
1002                 struct chsc_header request;
1003                 u32 operation_code : 2;
1004                 u32 : 30;
1005                 u32 key : 4;
1006                 u32 : 28;
1007                 u32 zeroes1;
1008                 u32 cub_addr1;
1009                 u32 zeroes2;
1010                 u32 cub_addr2;
1011                 u32 reserved[13];
1012                 struct chsc_header response;
1013                 u32 status : 8;
1014                 u32 : 4;
1015                 u32 fmt : 4;
1016                 u32 : 16;
1017         } *secm_area;
1018         int ret, ccode;
1019
1020         secm_area = page;
1021         secm_area->request.length = 0x0050;
1022         secm_area->request.code = 0x0016;
1023
1024         secm_area->key = PAGE_DEFAULT_KEY;
1025         secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1026         secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1027
1028         secm_area->operation_code = enable ? 0 : 1;
1029
1030         ccode = chsc(secm_area);
1031         if (ccode > 0)
1032                 return (ccode == 3) ? -ENODEV : -EBUSY;
1033
1034         switch (secm_area->response.code) {
1035         case 0x0001: /* Success. */
1036                 ret = 0;
1037                 break;
1038         case 0x0003: /* Invalid block. */
1039         case 0x0007: /* Invalid format. */
1040         case 0x0008: /* Other invalid block. */
1041                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1042                 ret = -EINVAL;
1043                 break;
1044         case 0x0004: /* Command not provided in model. */
1045                 CIO_CRW_EVENT(2, "Model does not provide secm\n");
1046                 ret = -EOPNOTSUPP;
1047                 break;
1048         case 0x0102: /* cub adresses incorrect */
1049                 CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1050                 ret = -EINVAL;
1051                 break;
1052         case 0x0103: /* key error */
1053                 CIO_CRW_EVENT(2, "Access key error in secm\n");
1054                 ret = -EINVAL;
1055                 break;
1056         case 0x0105: /* error while starting */
1057                 CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1058                 ret = -EIO;
1059                 break;
1060         default:
1061                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1062                               secm_area->response.code);
1063                 ret = -EIO;
1064         }
1065         return ret;
1066 }
1067
1068 int
1069 chsc_secm(struct channel_subsystem *css, int enable)
1070 {
1071         void  *secm_area;
1072         int ret;
1073
1074         secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1075         if (!secm_area)
1076                 return -ENOMEM;
1077
1078         mutex_lock(&css->mutex);
1079         if (enable && !css->cm_enabled) {
1080                 css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1081                 css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1082                 if (!css->cub_addr1 || !css->cub_addr2) {
1083                         free_page((unsigned long)css->cub_addr1);
1084                         free_page((unsigned long)css->cub_addr2);
1085                         free_page((unsigned long)secm_area);
1086                         mutex_unlock(&css->mutex);
1087                         return -ENOMEM;
1088                 }
1089         }
1090         ret = __chsc_do_secm(css, enable, secm_area);
1091         if (!ret) {
1092                 css->cm_enabled = enable;
1093                 if (css->cm_enabled) {
1094                         ret = chsc_add_cmg_attr(css);
1095                         if (ret) {
1096                                 memset(secm_area, 0, PAGE_SIZE);
1097                                 __chsc_do_secm(css, 0, secm_area);
1098                                 css->cm_enabled = 0;
1099                         }
1100                 } else
1101                         chsc_remove_cmg_attr(css);
1102         }
1103         if (enable && !css->cm_enabled) {
1104                 free_page((unsigned long)css->cub_addr1);
1105                 free_page((unsigned long)css->cub_addr2);
1106         }
1107         mutex_unlock(&css->mutex);
1108         free_page((unsigned long)secm_area);
1109         return ret;
1110 }
1111
1112 /*
1113  * Files for the channel path entries.
1114  */
1115 static ssize_t
1116 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1117 {
1118         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1119
1120         if (!chp)
1121                 return 0;
1122         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1123                 sprintf(buf, "offline\n"));
1124 }
1125
1126 static ssize_t
1127 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1128 {
1129         struct channel_path *cp = container_of(dev, struct channel_path, dev);
1130         char cmd[10];
1131         int num_args;
1132         int error;
1133
1134         num_args = sscanf(buf, "%5s", cmd);
1135         if (!num_args)
1136                 return count;
1137
1138         if (!strnicmp(cmd, "on", 2))
1139                 error = s390_vary_chpid(cp->id, 1);
1140         else if (!strnicmp(cmd, "off", 3))
1141                 error = s390_vary_chpid(cp->id, 0);
1142         else
1143                 error = -EINVAL;
1144
1145         return error < 0 ? error : count;
1146
1147 }
1148
1149 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1150
1151 static ssize_t
1152 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1153 {
1154         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1155
1156         if (!chp)
1157                 return 0;
1158         return sprintf(buf, "%x\n", chp->desc.desc);
1159 }
1160
1161 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1162
1163 static ssize_t
1164 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1165 {
1166         struct channel_path *chp = to_channelpath(dev);
1167
1168         if (!chp)
1169                 return 0;
1170         if (chp->cmg == -1) /* channel measurements not available */
1171                 return sprintf(buf, "unknown\n");
1172         return sprintf(buf, "%x\n", chp->cmg);
1173 }
1174
1175 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1176
1177 static ssize_t
1178 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1179 {
1180         struct channel_path *chp = to_channelpath(dev);
1181
1182         if (!chp)
1183                 return 0;
1184         if (chp->shared == -1) /* channel measurements not available */
1185                 return sprintf(buf, "unknown\n");
1186         return sprintf(buf, "%x\n", chp->shared);
1187 }
1188
1189 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1190
1191 static struct attribute * chp_attrs[] = {
1192         &dev_attr_status.attr,
1193         &dev_attr_type.attr,
1194         &dev_attr_cmg.attr,
1195         &dev_attr_shared.attr,
1196         NULL,
1197 };
1198
1199 static struct attribute_group chp_attr_group = {
1200         .attrs = chp_attrs,
1201 };
1202
1203 static void
1204 chp_release(struct device *dev)
1205 {
1206         struct channel_path *cp;
1207         
1208         cp = container_of(dev, struct channel_path, dev);
1209         kfree(cp);
1210 }
1211
1212 static int
1213 chsc_determine_channel_path_description(int chpid,
1214                                         struct channel_path_desc *desc)
1215 {
1216         int ccode, ret;
1217
1218         struct {
1219                 struct chsc_header request;
1220                 u32 : 24;
1221                 u32 first_chpid : 8;
1222                 u32 : 24;
1223                 u32 last_chpid : 8;
1224                 u32 zeroes1;
1225                 struct chsc_header response;
1226                 u32 zeroes2;
1227                 struct channel_path_desc desc;
1228         } *scpd_area;
1229
1230         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1231         if (!scpd_area)
1232                 return -ENOMEM;
1233
1234         scpd_area->request.length = 0x0010;
1235         scpd_area->request.code = 0x0002;
1236
1237         scpd_area->first_chpid = chpid;
1238         scpd_area->last_chpid = chpid;
1239
1240         ccode = chsc(scpd_area);
1241         if (ccode > 0) {
1242                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1243                 goto out;
1244         }
1245
1246         switch (scpd_area->response.code) {
1247         case 0x0001: /* Success. */
1248                 memcpy(desc, &scpd_area->desc,
1249                        sizeof(struct channel_path_desc));
1250                 ret = 0;
1251                 break;
1252         case 0x0003: /* Invalid block. */
1253         case 0x0007: /* Invalid format. */
1254         case 0x0008: /* Other invalid block. */
1255                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1256                 ret = -EINVAL;
1257                 break;
1258         case 0x0004: /* Command not provided in model. */
1259                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1260                 ret = -EOPNOTSUPP;
1261                 break;
1262         default:
1263                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1264                               scpd_area->response.code);
1265                 ret = -EIO;
1266         }
1267 out:
1268         free_page((unsigned long)scpd_area);
1269         return ret;
1270 }
1271
1272 static void
1273 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1274                           struct cmg_chars *chars)
1275 {
1276         switch (chp->cmg) {
1277         case 2:
1278         case 3:
1279                 chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1280                                          GFP_KERNEL);
1281                 if (chp->cmg_chars) {
1282                         int i, mask;
1283                         struct cmg_chars *cmg_chars;
1284
1285                         cmg_chars = chp->cmg_chars;
1286                         for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1287                                 mask = 0x80 >> (i + 3);
1288                                 if (cmcv & mask)
1289                                         cmg_chars->values[i] = chars->values[i];
1290                                 else
1291                                         cmg_chars->values[i] = 0;
1292                         }
1293                 }
1294                 break;
1295         default:
1296                 /* No cmg-dependent data. */
1297                 break;
1298         }
1299 }
1300
1301 static int
1302 chsc_get_channel_measurement_chars(struct channel_path *chp)
1303 {
1304         int ccode, ret;
1305
1306         struct {
1307                 struct chsc_header request;
1308                 u32 : 24;
1309                 u32 first_chpid : 8;
1310                 u32 : 24;
1311                 u32 last_chpid : 8;
1312                 u32 zeroes1;
1313                 struct chsc_header response;
1314                 u32 zeroes2;
1315                 u32 not_valid : 1;
1316                 u32 shared : 1;
1317                 u32 : 22;
1318                 u32 chpid : 8;
1319                 u32 cmcv : 5;
1320                 u32 : 11;
1321                 u32 cmgq : 8;
1322                 u32 cmg : 8;
1323                 u32 zeroes3;
1324                 u32 data[NR_MEASUREMENT_CHARS];
1325         } *scmc_area;
1326
1327         scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1328         if (!scmc_area)
1329                 return -ENOMEM;
1330
1331         scmc_area->request.length = 0x0010;
1332         scmc_area->request.code = 0x0022;
1333
1334         scmc_area->first_chpid = chp->id;
1335         scmc_area->last_chpid = chp->id;
1336
1337         ccode = chsc(scmc_area);
1338         if (ccode > 0) {
1339                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1340                 goto out;
1341         }
1342
1343         switch (scmc_area->response.code) {
1344         case 0x0001: /* Success. */
1345                 if (!scmc_area->not_valid) {
1346                         chp->cmg = scmc_area->cmg;
1347                         chp->shared = scmc_area->shared;
1348                         chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1349                                                   (struct cmg_chars *)
1350                                                   &scmc_area->data);
1351                 } else {
1352                         chp->cmg = -1;
1353                         chp->shared = -1;
1354                 }
1355                 ret = 0;
1356                 break;
1357         case 0x0003: /* Invalid block. */
1358         case 0x0007: /* Invalid format. */
1359         case 0x0008: /* Invalid bit combination. */
1360                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1361                 ret = -EINVAL;
1362                 break;
1363         case 0x0004: /* Command not provided. */
1364                 CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1365                 ret = -EOPNOTSUPP;
1366                 break;
1367         default:
1368                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1369                               scmc_area->response.code);
1370                 ret = -EIO;
1371         }
1372 out:
1373         free_page((unsigned long)scmc_area);
1374         return ret;
1375 }
1376
1377 /*
1378  * Entries for chpids on the system bus.
1379  * This replaces /proc/chpids.
1380  */
1381 static int
1382 new_channel_path(int chpid)
1383 {
1384         struct channel_path *chp;
1385         int ret;
1386
1387         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1388         if (!chp)
1389                 return -ENOMEM;
1390
1391         /* fill in status, etc. */
1392         chp->id = chpid;
1393         chp->state = 1;
1394         chp->dev.parent = &css[0]->device;
1395         chp->dev.release = chp_release;
1396         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1397
1398         /* Obtain channel path description and fill it in. */
1399         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1400         if (ret)
1401                 goto out_free;
1402         /* Get channel-measurement characteristics. */
1403         if (css_characteristics_avail && css_chsc_characteristics.scmc
1404             && css_chsc_characteristics.secm) {
1405                 ret = chsc_get_channel_measurement_chars(chp);
1406                 if (ret)
1407                         goto out_free;
1408         } else {
1409                 static int msg_done;
1410
1411                 if (!msg_done) {
1412                         printk(KERN_WARNING "cio: Channel measurements not "
1413                                "available, continuing.\n");
1414                         msg_done = 1;
1415                 }
1416                 chp->cmg = -1;
1417         }
1418
1419         /* make it known to the system */
1420         ret = device_register(&chp->dev);
1421         if (ret) {
1422                 printk(KERN_WARNING "%s: could not register %02x\n",
1423                        __func__, chpid);
1424                 goto out_free;
1425         }
1426         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1427         if (ret) {
1428                 device_unregister(&chp->dev);
1429                 goto out_free;
1430         }
1431         mutex_lock(&css[0]->mutex);
1432         if (css[0]->cm_enabled) {
1433                 ret = chsc_add_chp_cmg_attr(chp);
1434                 if (ret) {
1435                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1436                         device_unregister(&chp->dev);
1437                         mutex_unlock(&css[0]->mutex);
1438                         goto out_free;
1439                 }
1440         }
1441         css[0]->chps[chpid] = chp;
1442         mutex_unlock(&css[0]->mutex);
1443         return ret;
1444 out_free:
1445         kfree(chp);
1446         return ret;
1447 }
1448
1449 void *
1450 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1451 {
1452         struct channel_path *chp;
1453         struct channel_path_desc *desc;
1454
1455         chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1456         if (!chp)
1457                 return NULL;
1458         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1459         if (!desc)
1460                 return NULL;
1461         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1462         return desc;
1463 }
1464
1465 static int reset_channel_path(struct channel_path *chp)
1466 {
1467         int cc;
1468
1469         cc = rchp(chp->id);
1470         switch (cc) {
1471         case 0:
1472                 return 0;
1473         case 2:
1474                 return -EBUSY;
1475         default:
1476                 return -ENODEV;
1477         }
1478 }
1479
1480 static void reset_channel_paths_css(struct channel_subsystem *css)
1481 {
1482         int i;
1483
1484         for (i = 0; i <= __MAX_CHPID; i++) {
1485                 if (css->chps[i])
1486                         reset_channel_path(css->chps[i]);
1487         }
1488 }
1489
1490 void cio_reset_channel_paths(void)
1491 {
1492         int i;
1493
1494         for (i = 0; i <= __MAX_CSSID; i++) {
1495                 if (css[i] && css[i]->valid)
1496                         reset_channel_paths_css(css[i]);
1497         }
1498 }
1499
1500 static int __init
1501 chsc_alloc_sei_area(void)
1502 {
1503         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1504         if (!sei_page)
1505                 printk(KERN_WARNING"Can't allocate page for processing of " \
1506                        "chsc machine checks!\n");
1507         return (sei_page ? 0 : -ENOMEM);
1508 }
1509
1510 int __init
1511 chsc_enable_facility(int operation_code)
1512 {
1513         int ret;
1514         struct {
1515                 struct chsc_header request;
1516                 u8 reserved1:4;
1517                 u8 format:4;
1518                 u8 reserved2;
1519                 u16 operation_code;
1520                 u32 reserved3;
1521                 u32 reserved4;
1522                 u32 operation_data_area[252];
1523                 struct chsc_header response;
1524                 u32 reserved5:4;
1525                 u32 format2:4;
1526                 u32 reserved6:24;
1527         } *sda_area;
1528
1529         sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1530         if (!sda_area)
1531                 return -ENOMEM;
1532         sda_area->request.length = 0x0400;
1533         sda_area->request.code = 0x0031;
1534         sda_area->operation_code = operation_code;
1535
1536         ret = chsc(sda_area);
1537         if (ret > 0) {
1538                 ret = (ret == 3) ? -ENODEV : -EBUSY;
1539                 goto out;
1540         }
1541         switch (sda_area->response.code) {
1542         case 0x0001: /* everything ok */
1543                 ret = 0;
1544                 break;
1545         case 0x0003: /* invalid request block */
1546         case 0x0007:
1547                 ret = -EINVAL;
1548                 break;
1549         case 0x0004: /* command not provided */
1550         case 0x0101: /* facility not provided */
1551                 ret = -EOPNOTSUPP;
1552                 break;
1553         default: /* something went wrong */
1554                 ret = -EIO;
1555         }
1556  out:
1557         free_page((unsigned long)sda_area);
1558         return ret;
1559 }
1560
1561 subsys_initcall(chsc_alloc_sei_area);
1562
1563 struct css_general_char css_general_characteristics;
1564 struct css_chsc_char css_chsc_characteristics;
1565
1566 int __init
1567 chsc_determine_css_characteristics(void)
1568 {
1569         int result;
1570         struct {
1571                 struct chsc_header request;
1572                 u32 reserved1;
1573                 u32 reserved2;
1574                 u32 reserved3;
1575                 struct chsc_header response;
1576                 u32 reserved4;
1577                 u32 general_char[510];
1578                 u32 chsc_char[518];
1579         } *scsc_area;
1580
1581         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1582         if (!scsc_area) {
1583                 printk(KERN_WARNING"cio: Was not able to determine available" \
1584                        "CHSCs due to no memory.\n");
1585                 return -ENOMEM;
1586         }
1587
1588         scsc_area->request.length = 0x0010;
1589         scsc_area->request.code = 0x0010;
1590
1591         result = chsc(scsc_area);
1592         if (result) {
1593                 printk(KERN_WARNING"cio: Was not able to determine " \
1594                        "available CHSCs, cc=%i.\n", result);
1595                 result = -EIO;
1596                 goto exit;
1597         }
1598
1599         if (scsc_area->response.code != 1) {
1600                 printk(KERN_WARNING"cio: Was not able to determine " \
1601                        "available CHSCs.\n");
1602                 result = -EIO;
1603                 goto exit;
1604         }
1605         memcpy(&css_general_characteristics, scsc_area->general_char,
1606                sizeof(css_general_characteristics));
1607         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1608                sizeof(css_chsc_characteristics));
1609 exit:
1610         free_page ((unsigned long) scsc_area);
1611         return result;
1612 }
1613
1614 EXPORT_SYMBOL_GPL(css_general_characteristics);
1615 EXPORT_SYMBOL_GPL(css_chsc_characteristics);