Automatic merge with /usr/src/ntfs-2.6.git.
[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  *   $Revision: 1.119 $
5  *
6  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
7  *                            IBM Corporation
8  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
9  *               Cornelia Huck (cohuck@de.ibm.com)
10  *               Arnd Bergmann (arndb@de.ibm.com)
11  */
12
13 #include <linux/module.h>
14 #include <linux/config.h>
15 #include <linux/slab.h>
16 #include <linux/init.h>
17 #include <linux/device.h>
18
19 #include <asm/cio.h>
20
21 #include "css.h"
22 #include "cio.h"
23 #include "cio_debug.h"
24 #include "ioasm.h"
25 #include "chsc.h"
26
27 static struct channel_path *chps[NR_CHPIDS];
28
29 static void *sei_page;
30
31 static int new_channel_path(int chpid);
32
33 static inline void
34 set_chp_logically_online(int chp, int onoff)
35 {
36         chps[chp]->state = onoff;
37 }
38
39 static int
40 get_chp_status(int chp)
41 {
42         return (chps[chp] ? chps[chp]->state : -ENODEV);
43 }
44
45 void
46 chsc_validate_chpids(struct subchannel *sch)
47 {
48         int mask, chp;
49
50         for (chp = 0; chp <= 7; chp++) {
51                 mask = 0x80 >> chp;
52                 if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
53                         /* disable using this path */
54                         sch->opm &= ~mask;
55         }
56 }
57
58 void
59 chpid_is_actually_online(int chp)
60 {
61         int state;
62
63         state = get_chp_status(chp);
64         if (state < 0) {
65                 need_rescan = 1;
66                 queue_work(slow_path_wq, &slow_path_work);
67         } else
68                 WARN_ON(!state);
69 }
70
71 /* FIXME: this is _always_ called for every subchannel. shouldn't we
72  *        process more than one at a time? */
73 static int
74 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
75 {
76         int ccode, j;
77
78         struct {
79                 struct chsc_header request;
80                 u16 reserved1;
81                 u16 f_sch;        /* first subchannel */
82                 u16 reserved2;
83                 u16 l_sch;        /* last subchannel */
84                 u32 reserved3;
85                 struct chsc_header response;
86                 u32 reserved4;
87                 u8 sch_valid : 1;
88                 u8 dev_valid : 1;
89                 u8 st        : 3; /* subchannel type */
90                 u8 zeroes    : 3;
91                 u8  unit_addr;    /* unit address */
92                 u16 devno;        /* device number */
93                 u8 path_mask;
94                 u8 fla_valid_mask;
95                 u16 sch;          /* subchannel */
96                 u8 chpid[8];      /* chpids 0-7 */
97                 u16 fla[8];       /* full link addresses 0-7 */
98         } *ssd_area;
99
100         ssd_area = page;
101
102         ssd_area->request = (struct chsc_header) {
103                 .length = 0x0010,
104                 .code   = 0x0004,
105         };
106
107         ssd_area->f_sch = sch->irq;
108         ssd_area->l_sch = sch->irq;
109
110         ccode = chsc(ssd_area);
111         if (ccode > 0) {
112                 pr_debug("chsc returned with ccode = %d\n", ccode);
113                 return (ccode == 3) ? -ENODEV : -EBUSY;
114         }
115
116         switch (ssd_area->response.code) {
117         case 0x0001: /* everything ok */
118                 break;
119         case 0x0002:
120                 CIO_CRW_EVENT(2, "Invalid command!\n");
121                 return -EINVAL;
122         case 0x0003:
123                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
124                 return -EINVAL;
125         case 0x0004:
126                 CIO_CRW_EVENT(2, "Model does not provide ssd\n");
127                 return -EOPNOTSUPP;
128         default:
129                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
130                               ssd_area->response.code);
131                 return -EIO;
132         }
133
134         /*
135          * ssd_area->st stores the type of the detected
136          * subchannel, with the following definitions:
137          *
138          * 0: I/O subchannel:     All fields have meaning
139          * 1: CHSC subchannel:    Only sch_val, st and sch
140          *                        have meaning
141          * 2: Message subchannel: All fields except unit_addr
142          *                        have meaning
143          * 3: ADM subchannel:     Only sch_val, st and sch
144          *                        have meaning
145          *
146          * Other types are currently undefined.
147          */
148         if (ssd_area->st > 3) { /* uhm, that looks strange... */
149                 CIO_CRW_EVENT(0, "Strange subchannel type %d"
150                               " for sch %04x\n", ssd_area->st, sch->irq);
151                 /*
152                  * There may have been a new subchannel type defined in the
153                  * time since this code was written; since we don't know which
154                  * fields have meaning and what to do with it we just jump out
155                  */
156                 return 0;
157         } else {
158                 const char *type[4] = {"I/O", "chsc", "message", "ADM"};
159                 CIO_CRW_EVENT(6, "ssd: sch %04x is %s subchannel\n",
160                               sch->irq, type[ssd_area->st]);
161
162                 sch->ssd_info.valid = 1;
163                 sch->ssd_info.type = ssd_area->st;
164         }
165
166         if (ssd_area->st == 0 || ssd_area->st == 2) {
167                 for (j = 0; j < 8; j++) {
168                         if (!((0x80 >> j) & ssd_area->path_mask &
169                               ssd_area->fla_valid_mask))
170                                 continue;
171                         sch->ssd_info.chpid[j] = ssd_area->chpid[j];
172                         sch->ssd_info.fla[j]   = ssd_area->fla[j];
173                 }
174         }
175         return 0;
176 }
177
178 int
179 css_get_ssd_info(struct subchannel *sch)
180 {
181         int ret;
182         void *page;
183
184         page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
185         if (!page)
186                 return -ENOMEM;
187         spin_lock_irq(&sch->lock);
188         ret = chsc_get_sch_desc_irq(sch, page);
189         if (ret) {
190                 static int cio_chsc_err_msg;
191                 
192                 if (!cio_chsc_err_msg) {
193                         printk(KERN_ERR
194                                "chsc_get_sch_descriptions:"
195                                " Error %d while doing chsc; "
196                                "processing some machine checks may "
197                                "not work\n", ret);
198                         cio_chsc_err_msg = 1;
199                 }
200         }
201         spin_unlock_irq(&sch->lock);
202         free_page((unsigned long)page);
203         if (!ret) {
204                 int j, chpid;
205                 /* Allocate channel path structures, if needed. */
206                 for (j = 0; j < 8; j++) {
207                         chpid = sch->ssd_info.chpid[j];
208                         if (chpid && (get_chp_status(chpid) < 0))
209                             new_channel_path(chpid);
210                 }
211         }
212         return ret;
213 }
214
215 static int
216 s390_subchannel_remove_chpid(struct device *dev, void *data)
217 {
218         int j;
219         int mask;
220         struct subchannel *sch;
221         __u8 *chpid;
222         struct schib schib;
223
224         sch = to_subchannel(dev);
225         chpid = data;
226         for (j = 0; j < 8; j++)
227                 if (sch->schib.pmcw.chpid[j] == *chpid)
228                         break;
229         if (j >= 8)
230                 return 0;
231
232         mask = 0x80 >> j;
233         spin_lock(&sch->lock);
234
235         stsch(sch->irq, &schib);
236         if (!schib.pmcw.dnv)
237                 goto out_unreg;
238         memcpy(&sch->schib, &schib, sizeof(struct schib));
239         /* Check for single path devices. */
240         if (sch->schib.pmcw.pim == 0x80)
241                 goto out_unreg;
242         if (sch->vpm == mask)
243                 goto out_unreg;
244
245         if ((sch->schib.scsw.actl & (SCSW_ACTL_CLEAR_PEND |
246                                      SCSW_ACTL_HALT_PEND |
247                                      SCSW_ACTL_START_PEND |
248                                      SCSW_ACTL_RESUME_PEND)) &&
249             (sch->schib.pmcw.lpum == mask)) {
250                 int cc = cio_cancel(sch);
251                 
252                 if (cc == -ENODEV)
253                         goto out_unreg;
254
255                 if (cc == -EINVAL) {
256                         cc = cio_clear(sch);
257                         if (cc == -ENODEV)
258                                 goto out_unreg;
259                         /* Call handler. */
260                         if (sch->driver && sch->driver->termination)
261                                 sch->driver->termination(&sch->dev);
262                         goto out_unlock;
263                 }
264         } else if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
265                    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
266                    (sch->schib.pmcw.lpum == mask)) {
267                 int cc;
268
269                 cc = cio_clear(sch);
270                 if (cc == -ENODEV)
271                         goto out_unreg;
272                 /* Call handler. */
273                 if (sch->driver && sch->driver->termination)
274                         sch->driver->termination(&sch->dev);
275                 goto out_unlock;
276         }
277
278         /* trigger path verification. */
279         if (sch->driver && sch->driver->verify)
280                 sch->driver->verify(&sch->dev);
281 out_unlock:
282         spin_unlock(&sch->lock);
283         return 0;
284 out_unreg:
285         spin_unlock(&sch->lock);
286         sch->lpm = 0;
287         if (css_enqueue_subchannel_slow(sch->irq)) {
288                 css_clear_subchannel_slow_list();
289                 need_rescan = 1;
290         }
291         return 0;
292 }
293
294 static inline void
295 s390_set_chpid_offline( __u8 chpid)
296 {
297         char dbf_txt[15];
298
299         sprintf(dbf_txt, "chpr%x", chpid);
300         CIO_TRACE_EVENT(2, dbf_txt);
301
302         if (get_chp_status(chpid) <= 0)
303                 return;
304
305         bus_for_each_dev(&css_bus_type, NULL, &chpid,
306                          s390_subchannel_remove_chpid);
307
308         if (need_rescan || css_slow_subchannels_exist())
309                 queue_work(slow_path_wq, &slow_path_work);
310 }
311
312 static int
313 s390_process_res_acc_sch(u8 chpid, __u16 fla, u32 fla_mask,
314                          struct subchannel *sch)
315 {
316         int found;
317         int chp;
318         int ccode;
319         
320         found = 0;
321         for (chp = 0; chp <= 7; chp++)
322                 /*
323                  * check if chpid is in information updated by ssd
324                  */
325                 if (sch->ssd_info.valid &&
326                     sch->ssd_info.chpid[chp] == chpid &&
327                     (sch->ssd_info.fla[chp] & fla_mask) == fla) {
328                         found = 1;
329                         break;
330                 }
331         
332         if (found == 0)
333                 return 0;
334
335         /*
336          * Do a stsch to update our subchannel structure with the
337          * new path information and eventually check for logically
338          * offline chpids.
339          */
340         ccode = stsch(sch->irq, &sch->schib);
341         if (ccode > 0)
342                 return 0;
343
344         return 0x80 >> chp;
345 }
346
347 static int
348 s390_process_res_acc (u8 chpid, __u16 fla, u32 fla_mask)
349 {
350         struct subchannel *sch;
351         int irq, rc;
352         char dbf_txt[15];
353
354         sprintf(dbf_txt, "accpr%x", chpid);
355         CIO_TRACE_EVENT( 2, dbf_txt);
356         if (fla != 0) {
357                 sprintf(dbf_txt, "fla%x", fla);
358                 CIO_TRACE_EVENT( 2, dbf_txt);
359         }
360
361         /*
362          * I/O resources may have become accessible.
363          * Scan through all subchannels that may be concerned and
364          * do a validation on those.
365          * The more information we have (info), the less scanning
366          * will we have to do.
367          */
368
369         if (!get_chp_status(chpid))
370                 return 0; /* no need to do the rest */
371
372         rc = 0;
373         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
374                 int chp_mask, old_lpm;
375
376                 sch = get_subchannel_by_schid(irq);
377                 if (!sch) {
378                         struct schib schib;
379                         int ret;
380                         /*
381                          * We don't know the device yet, but since a path
382                          * may be available now to the device we'll have
383                          * to do recognition again.
384                          * Since we don't have any idea about which chpid
385                          * that beast may be on we'll have to do a stsch
386                          * on all devices, grr...
387                          */
388                         if (stsch(irq, &schib)) {
389                                 /* We're through */
390                                 if (need_rescan)
391                                         rc = -EAGAIN;
392                                 break;
393                         }
394                         if (need_rescan) {
395                                 rc = -EAGAIN;
396                                 continue;
397                         }
398                         /* Put it on the slow path. */
399                         ret = css_enqueue_subchannel_slow(irq);
400                         if (ret) {
401                                 css_clear_subchannel_slow_list();
402                                 need_rescan = 1;
403                         }
404                         rc = -EAGAIN;
405                         continue;
406                 }
407         
408                 spin_lock_irq(&sch->lock);
409
410                 chp_mask = s390_process_res_acc_sch(chpid, fla, fla_mask, sch);
411
412                 if (chp_mask == 0) {
413
414                         spin_unlock_irq(&sch->lock);
415
416                         if (fla_mask != 0)
417                                 break;
418                         else
419                                 continue;
420                 }
421                 old_lpm = sch->lpm;
422                 sch->lpm = ((sch->schib.pmcw.pim &
423                              sch->schib.pmcw.pam &
424                              sch->schib.pmcw.pom)
425                             | chp_mask) & sch->opm;
426                 if (!old_lpm && sch->lpm)
427                         device_trigger_reprobe(sch);
428                 else if (sch->driver && sch->driver->verify)
429                         sch->driver->verify(&sch->dev);
430
431                 spin_unlock_irq(&sch->lock);
432                 put_device(&sch->dev);
433                 if (fla_mask != 0)
434                         break;
435         }
436         return rc;
437 }
438
439 static int
440 __get_chpid_from_lir(void *data)
441 {
442         struct lir {
443                 u8  iq;
444                 u8  ic;
445                 u16 sci;
446                 /* incident-node descriptor */
447                 u32 indesc[28];
448                 /* attached-node descriptor */
449                 u32 andesc[28];
450                 /* incident-specific information */
451                 u32 isinfo[28];
452         } *lir;
453
454         lir = (struct lir*) data;
455         if (!(lir->iq&0x80))
456                 /* NULL link incident record */
457                 return -EINVAL;
458         if (!(lir->indesc[0]&0xc0000000))
459                 /* node descriptor not valid */
460                 return -EINVAL;
461         if (!(lir->indesc[0]&0x10000000))
462                 /* don't handle device-type nodes - FIXME */
463                 return -EINVAL;
464         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
465
466         return (u16) (lir->indesc[0]&0x000000ff);
467 }
468
469 int
470 chsc_process_crw(void)
471 {
472         int chpid, ret;
473         struct {
474                 struct chsc_header request;
475                 u32 reserved1;
476                 u32 reserved2;
477                 u32 reserved3;
478                 struct chsc_header response;
479                 u32 reserved4;
480                 u8  flags;
481                 u8  vf;         /* validity flags */
482                 u8  rs;         /* reporting source */
483                 u8  cc;         /* content code */
484                 u16 fla;        /* full link address */
485                 u16 rsid;       /* reporting source id */
486                 u32 reserved5;
487                 u32 reserved6;
488                 u32 ccdf[96];   /* content-code dependent field */
489                 /* ccdf has to be big enough for a link-incident record */
490         } *sei_area;
491
492         if (!sei_page)
493                 return 0;
494         /*
495          * build the chsc request block for store event information
496          * and do the call
497          * This function is only called by the machine check handler thread,
498          * so we don't need locking for the sei_page.
499          */
500         sei_area = sei_page;
501
502         CIO_TRACE_EVENT( 2, "prcss");
503         ret = 0;
504         do {
505                 int ccode, status;
506                 memset(sei_area, 0, sizeof(*sei_area));
507
508                 sei_area->request = (struct chsc_header) {
509                         .length = 0x0010,
510                         .code   = 0x000e,
511                 };
512
513                 ccode = chsc(sei_area);
514                 if (ccode > 0)
515                         return 0;
516
517                 switch (sei_area->response.code) {
518                         /* for debug purposes, check for problems */
519                 case 0x0001:
520                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
521                                         "successfully stored\n");
522                         break; /* everything ok */
523                 case 0x0002:
524                         CIO_CRW_EVENT(2,
525                                       "chsc_process_crw: invalid command!\n");
526                         return 0;
527                 case 0x0003:
528                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
529                                       "request block!\n");
530                         return 0;
531                 case 0x0005:
532                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
533                                       "information stored\n");
534                         return 0;
535                 default:
536                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
537                                       sei_area->response.code);
538                         return 0;
539                 }
540
541                 /* Check if we might have lost some information. */
542                 if (sei_area->flags & 0x40)
543                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
544                                        "has been lost due to overflow!\n");
545
546                 if (sei_area->rs != 4) {
547                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
548                                       "(%04X) isn't a chpid!\n",
549                                       sei_area->rsid);
550                         continue;
551                 }
552
553                 /* which kind of information was stored? */
554                 switch (sei_area->cc) {
555                 case 1: /* link incident*/
556                         CIO_CRW_EVENT(4, "chsc_process_crw: "
557                                       "channel subsystem reports link incident,"
558                                       " reporting source is chpid %x\n",
559                                       sei_area->rsid);
560                         chpid = __get_chpid_from_lir(sei_area->ccdf);
561                         if (chpid < 0)
562                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
563                                               __FUNCTION__);
564                         else
565                                 s390_set_chpid_offline(chpid);
566                         break;
567                         
568                 case 2: /* i/o resource accessibiliy */
569                         CIO_CRW_EVENT(4, "chsc_process_crw: "
570                                       "channel subsystem reports some I/O "
571                                       "devices may have become accessible\n");
572                         pr_debug("Data received after sei: \n");
573                         pr_debug("Validity flags: %x\n", sei_area->vf);
574                         
575                         /* allocate a new channel path structure, if needed */
576                         status = get_chp_status(sei_area->rsid);
577                         if (status < 0)
578                                 new_channel_path(sei_area->rsid);
579                         else if (!status)
580                                 return 0;
581                         if ((sei_area->vf & 0x80) == 0) {
582                                 pr_debug("chpid: %x\n", sei_area->rsid);
583                                 ret = s390_process_res_acc(sei_area->rsid,
584                                                            0, 0);
585                         } else if ((sei_area->vf & 0xc0) == 0x80) {
586                                 pr_debug("chpid: %x link addr: %x\n",
587                                          sei_area->rsid, sei_area->fla);
588                                 ret = s390_process_res_acc(sei_area->rsid,
589                                                            sei_area->fla,
590                                                            0xff00);
591                         } else if ((sei_area->vf & 0xc0) == 0xc0) {
592                                 pr_debug("chpid: %x full link addr: %x\n",
593                                          sei_area->rsid, sei_area->fla);
594                                 ret = s390_process_res_acc(sei_area->rsid,
595                                                            sei_area->fla,
596                                                            0xffff);
597                         }
598                         pr_debug("\n");
599                         
600                         break;
601                         
602                 default: /* other stuff */
603                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
604                                       sei_area->cc);
605                         break;
606                 }
607         } while (sei_area->flags & 0x80);
608         return ret;
609 }
610
611 static int
612 chp_add(int chpid)
613 {
614         struct subchannel *sch;
615         int irq, ret, rc;
616         char dbf_txt[15];
617
618         if (!get_chp_status(chpid))
619                 return 0; /* no need to do the rest */
620         
621         sprintf(dbf_txt, "cadd%x", chpid);
622         CIO_TRACE_EVENT(2, dbf_txt);
623
624         rc = 0;
625         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
626                 int i;
627
628                 sch = get_subchannel_by_schid(irq);
629                 if (!sch) {
630                         struct schib schib;
631
632                         if (stsch(irq, &schib)) {
633                                 /* We're through */
634                                 if (need_rescan)
635                                         rc = -EAGAIN;
636                                 break;
637                         }
638                         if (need_rescan) {
639                                 rc = -EAGAIN;
640                                 continue;
641                         }
642                         /* Put it on the slow path. */
643                         ret = css_enqueue_subchannel_slow(irq);
644                         if (ret) {
645                                 css_clear_subchannel_slow_list();
646                                 need_rescan = 1;
647                         }
648                         rc = -EAGAIN;
649                         continue;
650                 }
651         
652                 spin_lock(&sch->lock);
653                 for (i=0; i<8; i++)
654                         if (sch->schib.pmcw.chpid[i] == chpid) {
655                                 if (stsch(sch->irq, &sch->schib) != 0) {
656                                         /* Endgame. */
657                                         spin_unlock(&sch->lock);
658                                         return rc;
659                                 }
660                                 break;
661                         }
662                 if (i==8) {
663                         spin_unlock(&sch->lock);
664                         return rc;
665                 }
666                 sch->lpm = ((sch->schib.pmcw.pim &
667                              sch->schib.pmcw.pam &
668                              sch->schib.pmcw.pom)
669                             | 0x80 >> i) & sch->opm;
670
671                 if (sch->driver && sch->driver->verify)
672                         sch->driver->verify(&sch->dev);
673
674                 spin_unlock(&sch->lock);
675                 put_device(&sch->dev);
676         }
677         return rc;
678 }
679
680 /* 
681  * Handling of crw machine checks with channel path source.
682  */
683 int
684 chp_process_crw(int chpid, int on)
685 {
686         if (on == 0) {
687                 /* Path has gone. We use the link incident routine.*/
688                 s390_set_chpid_offline(chpid);
689                 return 0; /* De-register is async anyway. */
690         }
691         /*
692          * Path has come. Allocate a new channel path structure,
693          * if needed.
694          */
695         if (get_chp_status(chpid) < 0)
696                 new_channel_path(chpid);
697         /* Avoid the extra overhead in process_rec_acc. */
698         return chp_add(chpid);
699 }
700
701 static inline int
702 __check_for_io_and_kill(struct subchannel *sch, int index)
703 {
704         int cc;
705
706         if (!device_is_online(sch))
707                 /* cio could be doing I/O. */
708                 return 0;
709         cc = stsch(sch->irq, &sch->schib);
710         if (cc)
711                 return 0;
712         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
713                 device_set_waiting(sch);
714                 return 1;
715         }
716         return 0;
717 }
718
719 static inline void
720 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
721 {
722         int chp, old_lpm;
723         unsigned long flags;
724
725         if (!sch->ssd_info.valid)
726                 return;
727         
728         spin_lock_irqsave(&sch->lock, flags);
729         old_lpm = sch->lpm;
730         for (chp = 0; chp < 8; chp++) {
731                 if (sch->ssd_info.chpid[chp] != chpid)
732                         continue;
733
734                 if (on) {
735                         sch->opm |= (0x80 >> chp);
736                         sch->lpm |= (0x80 >> chp);
737                         if (!old_lpm)
738                                 device_trigger_reprobe(sch);
739                         else if (sch->driver && sch->driver->verify)
740                                 sch->driver->verify(&sch->dev);
741                 } else {
742                         sch->opm &= ~(0x80 >> chp);
743                         sch->lpm &= ~(0x80 >> chp);
744                         /*
745                          * Give running I/O a grace period in which it
746                          * can successfully terminate, even using the
747                          * just varied off path. Then kill it.
748                          */
749                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
750                                 if (css_enqueue_subchannel_slow(sch->irq)) {
751                                         css_clear_subchannel_slow_list();
752                                         need_rescan = 1;
753                                 }
754                         } else if (sch->driver && sch->driver->verify)
755                                 sch->driver->verify(&sch->dev);
756                 }
757                 break;
758         }
759         spin_unlock_irqrestore(&sch->lock, flags);
760 }
761
762 static int
763 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
764 {
765         struct subchannel *sch;
766         __u8 *chpid;
767
768         sch = to_subchannel(dev);
769         chpid = data;
770
771         __s390_subchannel_vary_chpid(sch, *chpid, 0);
772         return 0;
773 }
774
775 static int
776 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
777 {
778         struct subchannel *sch;
779         __u8 *chpid;
780
781         sch = to_subchannel(dev);
782         chpid = data;
783
784         __s390_subchannel_vary_chpid(sch, *chpid, 1);
785         return 0;
786 }
787
788 /*
789  * Function: s390_vary_chpid
790  * Varies the specified chpid online or offline
791  */
792 static int
793 s390_vary_chpid( __u8 chpid, int on)
794 {
795         char dbf_text[15];
796         int status, irq, ret;
797         struct subchannel *sch;
798
799         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
800         CIO_TRACE_EVENT( 2, dbf_text);
801
802         status = get_chp_status(chpid);
803         if (status < 0) {
804                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
805                 return -EINVAL;
806         }
807
808         if (!on && !status) {
809                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
810                 return -EINVAL;
811         }
812
813         set_chp_logically_online(chpid, on);
814
815         /*
816          * Redo PathVerification on the devices the chpid connects to
817          */
818
819         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
820                          s390_subchannel_vary_chpid_on :
821                          s390_subchannel_vary_chpid_off);
822         if (!on)
823                 goto out;
824         /* Scan for new devices on varied on path. */
825         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
826                 struct schib schib;
827
828                 if (need_rescan)
829                         break;
830                 sch = get_subchannel_by_schid(irq);
831                 if (sch) {
832                         put_device(&sch->dev);
833                         continue;
834                 }
835                 if (stsch(irq, &schib))
836                         /* We're through */
837                         break;
838                 /* Put it on the slow path. */
839                 ret = css_enqueue_subchannel_slow(irq);
840                 if (ret) {
841                         css_clear_subchannel_slow_list();
842                         need_rescan = 1;
843                 }
844         }
845 out:
846         if (need_rescan || css_slow_subchannels_exist())
847                 queue_work(slow_path_wq, &slow_path_work);
848         return 0;
849 }
850
851 /*
852  * Files for the channel path entries.
853  */
854 static ssize_t
855 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
856 {
857         struct channel_path *chp = container_of(dev, struct channel_path, dev);
858
859         if (!chp)
860                 return 0;
861         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
862                 sprintf(buf, "offline\n"));
863 }
864
865 static ssize_t
866 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
867 {
868         struct channel_path *cp = container_of(dev, struct channel_path, dev);
869         char cmd[10];
870         int num_args;
871         int error;
872
873         num_args = sscanf(buf, "%5s", cmd);
874         if (!num_args)
875                 return count;
876
877         if (!strnicmp(cmd, "on", 2))
878                 error = s390_vary_chpid(cp->id, 1);
879         else if (!strnicmp(cmd, "off", 3))
880                 error = s390_vary_chpid(cp->id, 0);
881         else
882                 error = -EINVAL;
883
884         return error < 0 ? error : count;
885
886 }
887
888 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
889
890 static ssize_t
891 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
892 {
893         struct channel_path *chp = container_of(dev, struct channel_path, dev);
894
895         if (!chp)
896                 return 0;
897         return sprintf(buf, "%x\n", chp->desc.desc);
898 }
899
900 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
901
902 static struct attribute * chp_attrs[] = {
903         &dev_attr_status.attr,
904         &dev_attr_type.attr,
905         NULL,
906 };
907
908 static struct attribute_group chp_attr_group = {
909         .attrs = chp_attrs,
910 };
911
912 static void
913 chp_release(struct device *dev)
914 {
915         struct channel_path *cp;
916         
917         cp = container_of(dev, struct channel_path, dev);
918         kfree(cp);
919 }
920
921 static int
922 chsc_determine_channel_path_description(int chpid,
923                                         struct channel_path_desc *desc)
924 {
925         int ccode, ret;
926
927         struct {
928                 struct chsc_header request;
929                 u32 : 24;
930                 u32 first_chpid : 8;
931                 u32 : 24;
932                 u32 last_chpid : 8;
933                 u32 zeroes1;
934                 struct chsc_header response;
935                 u32 zeroes2;
936                 struct channel_path_desc desc;
937         } *scpd_area;
938
939         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
940         if (!scpd_area)
941                 return -ENOMEM;
942
943         scpd_area->request = (struct chsc_header) {
944                 .length = 0x0010,
945                 .code   = 0x0002,
946         };
947
948         scpd_area->first_chpid = chpid;
949         scpd_area->last_chpid = chpid;
950
951         ccode = chsc(scpd_area);
952         if (ccode > 0) {
953                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
954                 goto out;
955         }
956
957         switch (scpd_area->response.code) {
958         case 0x0001: /* Success. */
959                 memcpy(desc, &scpd_area->desc,
960                        sizeof(struct channel_path_desc));
961                 ret = 0;
962                 break;
963         case 0x0003: /* Invalid block. */
964         case 0x0007: /* Invalid format. */
965         case 0x0008: /* Other invalid block. */
966                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
967                 ret = -EINVAL;
968                 break;
969         case 0x0004: /* Command not provided in model. */
970                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
971                 ret = -EOPNOTSUPP;
972                 break;
973         default:
974                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
975                               scpd_area->response.code);
976                 ret = -EIO;
977         }
978 out:
979         free_page((unsigned long)scpd_area);
980         return ret;
981 }
982
983 /*
984  * Entries for chpids on the system bus.
985  * This replaces /proc/chpids.
986  */
987 static int
988 new_channel_path(int chpid)
989 {
990         struct channel_path *chp;
991         int ret;
992
993         chp = kmalloc(sizeof(struct channel_path), GFP_KERNEL);
994         if (!chp)
995                 return -ENOMEM;
996         memset(chp, 0, sizeof(struct channel_path));
997
998         /* fill in status, etc. */
999         chp->id = chpid;
1000         chp->state = 1;
1001         chp->dev = (struct device) {
1002                 .parent  = &css_bus_device,
1003                 .release = chp_release,
1004         };
1005         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1006
1007         /* Obtain channel path description and fill it in. */
1008         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1009         if (ret)
1010                 goto out_free;
1011
1012         /* make it known to the system */
1013         ret = device_register(&chp->dev);
1014         if (ret) {
1015                 printk(KERN_WARNING "%s: could not register %02x\n",
1016                        __func__, chpid);
1017                 goto out_free;
1018         }
1019         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1020         if (ret) {
1021                 device_unregister(&chp->dev);
1022                 goto out_free;
1023         } else
1024                 chps[chpid] = chp;
1025         return ret;
1026 out_free:
1027         kfree(chp);
1028         return ret;
1029 }
1030
1031 void *
1032 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1033 {
1034         struct channel_path *chp;
1035         struct channel_path_desc *desc;
1036
1037         chp = chps[sch->schib.pmcw.chpid[chp_no]];
1038         if (!chp)
1039                 return NULL;
1040         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1041         if (!desc)
1042                 return NULL;
1043         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1044         return desc;
1045 }
1046
1047
1048 static int __init
1049 chsc_alloc_sei_area(void)
1050 {
1051         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1052         if (!sei_page)
1053                 printk(KERN_WARNING"Can't allocate page for processing of " \
1054                        "chsc machine checks!\n");
1055         return (sei_page ? 0 : -ENOMEM);
1056 }
1057
1058 subsys_initcall(chsc_alloc_sei_area);
1059
1060 struct css_general_char css_general_characteristics;
1061 struct css_chsc_char css_chsc_characteristics;
1062
1063 int __init
1064 chsc_determine_css_characteristics(void)
1065 {
1066         int result;
1067         struct {
1068                 struct chsc_header request;
1069                 u32 reserved1;
1070                 u32 reserved2;
1071                 u32 reserved3;
1072                 struct chsc_header response;
1073                 u32 reserved4;
1074                 u32 general_char[510];
1075                 u32 chsc_char[518];
1076         } *scsc_area;
1077
1078         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1079         if (!scsc_area) {
1080                 printk(KERN_WARNING"cio: Was not able to determine available" \
1081                        "CHSCs due to no memory.\n");
1082                 return -ENOMEM;
1083         }
1084
1085         scsc_area->request = (struct chsc_header) {
1086                 .length = 0x0010,
1087                 .code   = 0x0010,
1088         };
1089
1090         result = chsc(scsc_area);
1091         if (result) {
1092                 printk(KERN_WARNING"cio: Was not able to determine " \
1093                        "available CHSCs, cc=%i.\n", result);
1094                 result = -EIO;
1095                 goto exit;
1096         }
1097
1098         if (scsc_area->response.code != 1) {
1099                 printk(KERN_WARNING"cio: Was not able to determine " \
1100                        "available CHSCs.\n");
1101                 result = -EIO;
1102                 goto exit;
1103         }
1104         memcpy(&css_general_characteristics, scsc_area->general_char,
1105                sizeof(css_general_characteristics));
1106         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1107                sizeof(css_chsc_characteristics));
1108 exit:
1109         free_page ((unsigned long) scsc_area);
1110         return result;
1111 }
1112
1113 EXPORT_SYMBOL_GPL(css_general_characteristics);
1114 EXPORT_SYMBOL_GPL(css_chsc_characteristics);