xref: /linux/drivers/s390/cio/chsc.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 	} __attribute__ ((packed)) *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, mask;
204 		/* Allocate channel path structures, if needed. */
205 		for (j = 0; j < 8; j++) {
206 			mask = 0x80 >> j;
207 			chpid = sch->ssd_info.chpid[j];
208 			if ((sch->schib.pmcw.pim & mask) &&
209 			    (get_chp_status(chpid) < 0))
210 			    new_channel_path(chpid);
211 		}
212 	}
213 	return ret;
214 }
215 
216 static int
217 s390_subchannel_remove_chpid(struct device *dev, void *data)
218 {
219 	int j;
220 	int mask;
221 	struct subchannel *sch;
222 	struct channel_path *chpid;
223 	struct schib schib;
224 
225 	sch = to_subchannel(dev);
226 	chpid = data;
227 	for (j = 0; j < 8; j++) {
228 		mask = 0x80 >> j;
229 		if ((sch->schib.pmcw.pim & mask) &&
230 		    (sch->schib.pmcw.chpid[j] == chpid->id))
231 			break;
232 	}
233 	if (j >= 8)
234 		return 0;
235 
236 	spin_lock_irq(sch->lock);
237 
238 	stsch(sch->schid, &schib);
239 	if (!schib.pmcw.dnv)
240 		goto out_unreg;
241 	memcpy(&sch->schib, &schib, sizeof(struct schib));
242 	/* Check for single path devices. */
243 	if (sch->schib.pmcw.pim == 0x80)
244 		goto out_unreg;
245 
246 	if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
247 	    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
248 	    (sch->schib.pmcw.lpum == mask)) {
249 		int cc;
250 
251 		cc = cio_clear(sch);
252 		if (cc == -ENODEV)
253 			goto out_unreg;
254 		/* Request retry of internal operation. */
255 		device_set_intretry(sch);
256 		/* Call handler. */
257 		if (sch->driver && sch->driver->termination)
258 			sch->driver->termination(&sch->dev);
259 		goto out_unlock;
260 	}
261 
262 	/* trigger path verification. */
263 	if (sch->driver && sch->driver->verify)
264 		sch->driver->verify(&sch->dev);
265 	else if (sch->lpm == mask)
266 		goto out_unreg;
267 out_unlock:
268 	spin_unlock_irq(sch->lock);
269 	return 0;
270 out_unreg:
271 	spin_unlock_irq(sch->lock);
272 	sch->lpm = 0;
273 	if (css_enqueue_subchannel_slow(sch->schid)) {
274 		css_clear_subchannel_slow_list();
275 		need_rescan = 1;
276 	}
277 	return 0;
278 }
279 
280 static void
281 s390_set_chpid_offline( __u8 chpid)
282 {
283 	char dbf_txt[15];
284 	struct device *dev;
285 
286 	sprintf(dbf_txt, "chpr%x", chpid);
287 	CIO_TRACE_EVENT(2, dbf_txt);
288 
289 	if (get_chp_status(chpid) <= 0)
290 		return;
291 	dev = get_device(&css[0]->chps[chpid]->dev);
292 	bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
293 			 s390_subchannel_remove_chpid);
294 
295 	if (need_rescan || css_slow_subchannels_exist())
296 		queue_work(slow_path_wq, &slow_path_work);
297 	put_device(dev);
298 }
299 
300 struct res_acc_data {
301 	struct channel_path *chp;
302 	u32 fla_mask;
303 	u16 fla;
304 };
305 
306 static int
307 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
308 {
309 	int found;
310 	int chp;
311 	int ccode;
312 
313 	found = 0;
314 	for (chp = 0; chp <= 7; chp++)
315 		/*
316 		 * check if chpid is in information updated by ssd
317 		 */
318 		if (sch->ssd_info.valid &&
319 		    sch->ssd_info.chpid[chp] == res_data->chp->id &&
320 		    (sch->ssd_info.fla[chp] & res_data->fla_mask)
321 		    == res_data->fla) {
322 			found = 1;
323 			break;
324 		}
325 
326 	if (found == 0)
327 		return 0;
328 
329 	/*
330 	 * Do a stsch to update our subchannel structure with the
331 	 * new path information and eventually check for logically
332 	 * offline chpids.
333 	 */
334 	ccode = stsch(sch->schid, &sch->schib);
335 	if (ccode > 0)
336 		return 0;
337 
338 	return 0x80 >> chp;
339 }
340 
341 static int
342 s390_process_res_acc_new_sch(struct subchannel_id schid)
343 {
344 	struct schib schib;
345 	int ret;
346 	/*
347 	 * We don't know the device yet, but since a path
348 	 * may be available now to the device we'll have
349 	 * to do recognition again.
350 	 * Since we don't have any idea about which chpid
351 	 * that beast may be on we'll have to do a stsch
352 	 * on all devices, grr...
353 	 */
354 	if (stsch_err(schid, &schib))
355 		/* We're through */
356 		return need_rescan ? -EAGAIN : -ENXIO;
357 
358 	/* Put it on the slow path. */
359 	ret = css_enqueue_subchannel_slow(schid);
360 	if (ret) {
361 		css_clear_subchannel_slow_list();
362 		need_rescan = 1;
363 		return -EAGAIN;
364 	}
365 	return 0;
366 }
367 
368 static int
369 __s390_process_res_acc(struct subchannel_id schid, void *data)
370 {
371 	int chp_mask, old_lpm;
372 	struct res_acc_data *res_data;
373 	struct subchannel *sch;
374 
375 	res_data = data;
376 	sch = get_subchannel_by_schid(schid);
377 	if (!sch)
378 		/* Check if a subchannel is newly available. */
379 		return s390_process_res_acc_new_sch(schid);
380 
381 	spin_lock_irq(sch->lock);
382 
383 	chp_mask = s390_process_res_acc_sch(res_data, sch);
384 
385 	if (chp_mask == 0) {
386 		spin_unlock_irq(sch->lock);
387 		put_device(&sch->dev);
388 		return 0;
389 	}
390 	old_lpm = sch->lpm;
391 	sch->lpm = ((sch->schib.pmcw.pim &
392 		     sch->schib.pmcw.pam &
393 		     sch->schib.pmcw.pom)
394 		    | chp_mask) & sch->opm;
395 	if (!old_lpm && sch->lpm)
396 		device_trigger_reprobe(sch);
397 	else if (sch->driver && sch->driver->verify)
398 		sch->driver->verify(&sch->dev);
399 
400 	spin_unlock_irq(sch->lock);
401 	put_device(&sch->dev);
402 	return 0;
403 }
404 
405 
406 static int
407 s390_process_res_acc (struct res_acc_data *res_data)
408 {
409 	int rc;
410 	char dbf_txt[15];
411 
412 	sprintf(dbf_txt, "accpr%x", res_data->chp->id);
413 	CIO_TRACE_EVENT( 2, dbf_txt);
414 	if (res_data->fla != 0) {
415 		sprintf(dbf_txt, "fla%x", res_data->fla);
416 		CIO_TRACE_EVENT( 2, dbf_txt);
417 	}
418 
419 	/*
420 	 * I/O resources may have become accessible.
421 	 * Scan through all subchannels that may be concerned and
422 	 * do a validation on those.
423 	 * The more information we have (info), the less scanning
424 	 * will we have to do.
425 	 */
426 	rc = for_each_subchannel(__s390_process_res_acc, res_data);
427 	if (css_slow_subchannels_exist())
428 		rc = -EAGAIN;
429 	else if (rc != -EAGAIN)
430 		rc = 0;
431 	return rc;
432 }
433 
434 static int
435 __get_chpid_from_lir(void *data)
436 {
437 	struct lir {
438 		u8  iq;
439 		u8  ic;
440 		u16 sci;
441 		/* incident-node descriptor */
442 		u32 indesc[28];
443 		/* attached-node descriptor */
444 		u32 andesc[28];
445 		/* incident-specific information */
446 		u32 isinfo[28];
447 	} __attribute__ ((packed)) *lir;
448 
449 	lir = data;
450 	if (!(lir->iq&0x80))
451 		/* NULL link incident record */
452 		return -EINVAL;
453 	if (!(lir->indesc[0]&0xc0000000))
454 		/* node descriptor not valid */
455 		return -EINVAL;
456 	if (!(lir->indesc[0]&0x10000000))
457 		/* don't handle device-type nodes - FIXME */
458 		return -EINVAL;
459 	/* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
460 
461 	return (u16) (lir->indesc[0]&0x000000ff);
462 }
463 
464 struct chsc_sei_area {
465 	struct chsc_header request;
466 	u32 reserved1;
467 	u32 reserved2;
468 	u32 reserved3;
469 	struct chsc_header response;
470 	u32 reserved4;
471 	u8  flags;
472 	u8  vf;		/* validity flags */
473 	u8  rs;		/* reporting source */
474 	u8  cc;		/* content code */
475 	u16 fla;	/* full link address */
476 	u16 rsid;	/* reporting source id */
477 	u32 reserved5;
478 	u32 reserved6;
479 	u8 ccdf[4096 - 16 - 24];	/* content-code dependent field */
480 	/* ccdf has to be big enough for a link-incident record */
481 } __attribute__ ((packed));
482 
483 static int chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
484 {
485 	int chpid;
486 
487 	CIO_CRW_EVENT(4, "chsc: link incident (rs=%02x, rs_id=%04x)\n",
488 		      sei_area->rs, sei_area->rsid);
489 	if (sei_area->rs != 4)
490 		return 0;
491 	chpid = __get_chpid_from_lir(sei_area->ccdf);
492 	if (chpid < 0)
493 		CIO_CRW_EVENT(4, "chsc: link incident - invalid LIR\n");
494 	else
495 		s390_set_chpid_offline(chpid);
496 
497 	return 0;
498 }
499 
500 static int chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
501 {
502 	struct res_acc_data res_data;
503 	struct device *dev;
504 	int status;
505 	int rc;
506 
507 	CIO_CRW_EVENT(4, "chsc: resource accessibility event (rs=%02x, "
508 		      "rs_id=%04x)\n", sei_area->rs, sei_area->rsid);
509 	if (sei_area->rs != 4)
510 		return 0;
511 	/* allocate a new channel path structure, if needed */
512 	status = get_chp_status(sei_area->rsid);
513 	if (status < 0)
514 		new_channel_path(sei_area->rsid);
515 	else if (!status)
516 		return 0;
517 	dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
518 	memset(&res_data, 0, sizeof(struct res_acc_data));
519 	res_data.chp = to_channelpath(dev);
520 	if ((sei_area->vf & 0xc0) != 0) {
521 		res_data.fla = sei_area->fla;
522 		if ((sei_area->vf & 0xc0) == 0xc0)
523 			/* full link address */
524 			res_data.fla_mask = 0xffff;
525 		else
526 			/* link address */
527 			res_data.fla_mask = 0xff00;
528 	}
529 	rc = s390_process_res_acc(&res_data);
530 	put_device(dev);
531 
532 	return rc;
533 }
534 
535 static int chsc_process_sei(struct chsc_sei_area *sei_area)
536 {
537 	int rc;
538 
539 	/* Check if we might have lost some information. */
540 	if (sei_area->flags & 0x40)
541 		CIO_CRW_EVENT(2, "chsc: event overflow\n");
542 	/* which kind of information was stored? */
543 	rc = 0;
544 	switch (sei_area->cc) {
545 	case 1: /* link incident*/
546 		rc = chsc_process_sei_link_incident(sei_area);
547 		break;
548 	case 2: /* i/o resource accessibiliy */
549 		rc = chsc_process_sei_res_acc(sei_area);
550 		break;
551 	default: /* other stuff */
552 		CIO_CRW_EVENT(4, "chsc: unhandled sei content code %d\n",
553 			      sei_area->cc);
554 		break;
555 	}
556 
557 	return rc;
558 }
559 
560 int chsc_process_crw(void)
561 {
562 	struct chsc_sei_area *sei_area;
563 	int ret;
564 	int rc;
565 
566 	if (!sei_page)
567 		return 0;
568 	/* Access to sei_page is serialized through machine check handler
569 	 * thread, so no need for locking. */
570 	sei_area = sei_page;
571 
572 	CIO_TRACE_EVENT( 2, "prcss");
573 	ret = 0;
574 	do {
575 		memset(sei_area, 0, sizeof(*sei_area));
576 		sei_area->request.length = 0x0010;
577 		sei_area->request.code = 0x000e;
578 		if (chsc(sei_area))
579 			break;
580 
581 		if (sei_area->response.code == 0x0001) {
582 			CIO_CRW_EVENT(4, "chsc: sei successful\n");
583 			rc = chsc_process_sei(sei_area);
584 			if (rc)
585 				ret = rc;
586 		} else {
587 			CIO_CRW_EVENT(2, "chsc: sei failed (rc=%04x)\n",
588 				      sei_area->response.code);
589 			ret = 0;
590 			break;
591 		}
592 	} while (sei_area->flags & 0x80);
593 
594 	return ret;
595 }
596 
597 static int
598 __chp_add_new_sch(struct subchannel_id schid)
599 {
600 	struct schib schib;
601 	int ret;
602 
603 	if (stsch_err(schid, &schib))
604 		/* We're through */
605 		return need_rescan ? -EAGAIN : -ENXIO;
606 
607 	/* Put it on the slow path. */
608 	ret = css_enqueue_subchannel_slow(schid);
609 	if (ret) {
610 		css_clear_subchannel_slow_list();
611 		need_rescan = 1;
612 		return -EAGAIN;
613 	}
614 	return 0;
615 }
616 
617 
618 static int
619 __chp_add(struct subchannel_id schid, void *data)
620 {
621 	int i, mask;
622 	struct channel_path *chp;
623 	struct subchannel *sch;
624 
625 	chp = data;
626 	sch = get_subchannel_by_schid(schid);
627 	if (!sch)
628 		/* Check if the subchannel is now available. */
629 		return __chp_add_new_sch(schid);
630 	spin_lock_irq(sch->lock);
631 	for (i=0; i<8; i++) {
632 		mask = 0x80 >> i;
633 		if ((sch->schib.pmcw.pim & mask) &&
634 		    (sch->schib.pmcw.chpid[i] == chp->id)) {
635 			if (stsch(sch->schid, &sch->schib) != 0) {
636 				/* Endgame. */
637 				spin_unlock_irq(sch->lock);
638 				return -ENXIO;
639 			}
640 			break;
641 		}
642 	}
643 	if (i==8) {
644 		spin_unlock_irq(sch->lock);
645 		return 0;
646 	}
647 	sch->lpm = ((sch->schib.pmcw.pim &
648 		     sch->schib.pmcw.pam &
649 		     sch->schib.pmcw.pom)
650 		    | mask) & sch->opm;
651 
652 	if (sch->driver && sch->driver->verify)
653 		sch->driver->verify(&sch->dev);
654 
655 	spin_unlock_irq(sch->lock);
656 	put_device(&sch->dev);
657 	return 0;
658 }
659 
660 static int
661 chp_add(int chpid)
662 {
663 	int rc;
664 	char dbf_txt[15];
665 	struct device *dev;
666 
667 	if (!get_chp_status(chpid))
668 		return 0; /* no need to do the rest */
669 
670 	sprintf(dbf_txt, "cadd%x", chpid);
671 	CIO_TRACE_EVENT(2, dbf_txt);
672 
673 	dev = get_device(&css[0]->chps[chpid]->dev);
674 	rc = for_each_subchannel(__chp_add, to_channelpath(dev));
675 	if (css_slow_subchannels_exist())
676 		rc = -EAGAIN;
677 	if (rc != -EAGAIN)
678 		rc = 0;
679 	put_device(dev);
680 	return rc;
681 }
682 
683 /*
684  * Handling of crw machine checks with channel path source.
685  */
686 int
687 chp_process_crw(int chpid, int on)
688 {
689 	if (on == 0) {
690 		/* Path has gone. We use the link incident routine.*/
691 		s390_set_chpid_offline(chpid);
692 		return 0; /* De-register is async anyway. */
693 	}
694 	/*
695 	 * Path has come. Allocate a new channel path structure,
696 	 * if needed.
697 	 */
698 	if (get_chp_status(chpid) < 0)
699 		new_channel_path(chpid);
700 	/* Avoid the extra overhead in process_rec_acc. */
701 	return chp_add(chpid);
702 }
703 
704 static int check_for_io_on_path(struct subchannel *sch, int index)
705 {
706 	int cc;
707 
708 	cc = stsch(sch->schid, &sch->schib);
709 	if (cc)
710 		return 0;
711 	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index))
712 		return 1;
713 	return 0;
714 }
715 
716 static void terminate_internal_io(struct subchannel *sch)
717 {
718 	if (cio_clear(sch)) {
719 		/* Recheck device in case clear failed. */
720 		sch->lpm = 0;
721 		if (device_trigger_verify(sch) != 0) {
722 			if(css_enqueue_subchannel_slow(sch->schid)) {
723 				css_clear_subchannel_slow_list();
724 				need_rescan = 1;
725 			}
726 		}
727 		return;
728 	}
729 	/* Request retry of internal operation. */
730 	device_set_intretry(sch);
731 	/* Call handler. */
732 	if (sch->driver && sch->driver->termination)
733 		sch->driver->termination(&sch->dev);
734 }
735 
736 static void
737 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
738 {
739 	int chp, old_lpm;
740 	unsigned long flags;
741 
742 	if (!sch->ssd_info.valid)
743 		return;
744 
745 	spin_lock_irqsave(sch->lock, flags);
746 	old_lpm = sch->lpm;
747 	for (chp = 0; chp < 8; chp++) {
748 		if (sch->ssd_info.chpid[chp] != chpid)
749 			continue;
750 
751 		if (on) {
752 			sch->opm |= (0x80 >> chp);
753 			sch->lpm |= (0x80 >> chp);
754 			if (!old_lpm)
755 				device_trigger_reprobe(sch);
756 			else if (sch->driver && sch->driver->verify)
757 				sch->driver->verify(&sch->dev);
758 			break;
759 		}
760 		sch->opm &= ~(0x80 >> chp);
761 		sch->lpm &= ~(0x80 >> chp);
762 		if (check_for_io_on_path(sch, chp)) {
763 			if (device_is_online(sch))
764 				/* Path verification is done after killing. */
765 				device_kill_io(sch);
766 			else
767 				/* Kill and retry internal I/O. */
768 				terminate_internal_io(sch);
769 		} else if (!sch->lpm) {
770 			if (device_trigger_verify(sch) != 0) {
771 				if (css_enqueue_subchannel_slow(sch->schid)) {
772 					css_clear_subchannel_slow_list();
773 					need_rescan = 1;
774 				}
775 			}
776 		} else if (sch->driver && sch->driver->verify)
777 			sch->driver->verify(&sch->dev);
778 		break;
779 	}
780 	spin_unlock_irqrestore(sch->lock, flags);
781 }
782 
783 static int
784 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
785 {
786 	struct subchannel *sch;
787 	__u8 *chpid;
788 
789 	sch = to_subchannel(dev);
790 	chpid = data;
791 
792 	__s390_subchannel_vary_chpid(sch, *chpid, 0);
793 	return 0;
794 }
795 
796 static int
797 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
798 {
799 	struct subchannel *sch;
800 	__u8 *chpid;
801 
802 	sch = to_subchannel(dev);
803 	chpid = data;
804 
805 	__s390_subchannel_vary_chpid(sch, *chpid, 1);
806 	return 0;
807 }
808 
809 static int
810 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
811 {
812 	struct schib schib;
813 	struct subchannel *sch;
814 
815 	sch = get_subchannel_by_schid(schid);
816 	if (sch) {
817 		put_device(&sch->dev);
818 		return 0;
819 	}
820 	if (stsch_err(schid, &schib))
821 		/* We're through */
822 		return -ENXIO;
823 	/* Put it on the slow path. */
824 	if (css_enqueue_subchannel_slow(schid)) {
825 		css_clear_subchannel_slow_list();
826 		need_rescan = 1;
827 		return -EAGAIN;
828 	}
829 	return 0;
830 }
831 
832 /*
833  * Function: s390_vary_chpid
834  * Varies the specified chpid online or offline
835  */
836 static int
837 s390_vary_chpid( __u8 chpid, int on)
838 {
839 	char dbf_text[15];
840 	int status;
841 
842 	sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
843 	CIO_TRACE_EVENT( 2, dbf_text);
844 
845 	status = get_chp_status(chpid);
846 	if (status < 0) {
847 		printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
848 		return -EINVAL;
849 	}
850 
851 	if (!on && !status) {
852 		printk(KERN_ERR "chpid %x is already offline\n", chpid);
853 		return -EINVAL;
854 	}
855 
856 	set_chp_logically_online(chpid, on);
857 
858 	/*
859 	 * Redo PathVerification on the devices the chpid connects to
860 	 */
861 
862 	bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
863 			 s390_subchannel_vary_chpid_on :
864 			 s390_subchannel_vary_chpid_off);
865 	if (on)
866 		/* Scan for new devices on varied on path. */
867 		for_each_subchannel(__s390_vary_chpid_on, NULL);
868 	if (need_rescan || css_slow_subchannels_exist())
869 		queue_work(slow_path_wq, &slow_path_work);
870 	return 0;
871 }
872 
873 /*
874  * Channel measurement related functions
875  */
876 static ssize_t
877 chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
878 			   size_t count)
879 {
880 	struct channel_path *chp;
881 	unsigned int size;
882 
883 	chp = to_channelpath(container_of(kobj, struct device, kobj));
884 	if (!chp->cmg_chars)
885 		return 0;
886 
887 	size = sizeof(struct cmg_chars);
888 
889 	if (off > size)
890 		return 0;
891 	if (off + count > size)
892 		count = size - off;
893 	memcpy(buf, chp->cmg_chars + off, count);
894 	return count;
895 }
896 
897 static struct bin_attribute chp_measurement_chars_attr = {
898 	.attr = {
899 		.name = "measurement_chars",
900 		.mode = S_IRUSR,
901 		.owner = THIS_MODULE,
902 	},
903 	.size = sizeof(struct cmg_chars),
904 	.read = chp_measurement_chars_read,
905 };
906 
907 static void
908 chp_measurement_copy_block(struct cmg_entry *buf,
909 			   struct channel_subsystem *css, int chpid)
910 {
911 	void *area;
912 	struct cmg_entry *entry, reference_buf;
913 	int idx;
914 
915 	if (chpid < 128) {
916 		area = css->cub_addr1;
917 		idx = chpid;
918 	} else {
919 		area = css->cub_addr2;
920 		idx = chpid - 128;
921 	}
922 	entry = area + (idx * sizeof(struct cmg_entry));
923 	do {
924 		memcpy(buf, entry, sizeof(*entry));
925 		memcpy(&reference_buf, entry, sizeof(*entry));
926 	} while (reference_buf.values[0] != buf->values[0]);
927 }
928 
929 static ssize_t
930 chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
931 {
932 	struct channel_path *chp;
933 	struct channel_subsystem *css;
934 	unsigned int size;
935 
936 	chp = to_channelpath(container_of(kobj, struct device, kobj));
937 	css = to_css(chp->dev.parent);
938 
939 	size = sizeof(struct cmg_entry);
940 
941 	/* Only allow single reads. */
942 	if (off || count < size)
943 		return 0;
944 	chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
945 	count = size;
946 	return count;
947 }
948 
949 static struct bin_attribute chp_measurement_attr = {
950 	.attr = {
951 		.name = "measurement",
952 		.mode = S_IRUSR,
953 		.owner = THIS_MODULE,
954 	},
955 	.size = sizeof(struct cmg_entry),
956 	.read = chp_measurement_read,
957 };
958 
959 static void
960 chsc_remove_chp_cmg_attr(struct channel_path *chp)
961 {
962 	device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
963 	device_remove_bin_file(&chp->dev, &chp_measurement_attr);
964 }
965 
966 static int
967 chsc_add_chp_cmg_attr(struct channel_path *chp)
968 {
969 	int ret;
970 
971 	ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
972 	if (ret)
973 		return ret;
974 	ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
975 	if (ret)
976 		device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
977 	return ret;
978 }
979 
980 static void
981 chsc_remove_cmg_attr(struct channel_subsystem *css)
982 {
983 	int i;
984 
985 	for (i = 0; i <= __MAX_CHPID; i++) {
986 		if (!css->chps[i])
987 			continue;
988 		chsc_remove_chp_cmg_attr(css->chps[i]);
989 	}
990 }
991 
992 static int
993 chsc_add_cmg_attr(struct channel_subsystem *css)
994 {
995 	int i, ret;
996 
997 	ret = 0;
998 	for (i = 0; i <= __MAX_CHPID; i++) {
999 		if (!css->chps[i])
1000 			continue;
1001 		ret = chsc_add_chp_cmg_attr(css->chps[i]);
1002 		if (ret)
1003 			goto cleanup;
1004 	}
1005 	return ret;
1006 cleanup:
1007 	for (--i; i >= 0; i--) {
1008 		if (!css->chps[i])
1009 			continue;
1010 		chsc_remove_chp_cmg_attr(css->chps[i]);
1011 	}
1012 	return ret;
1013 }
1014 
1015 
1016 static int
1017 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1018 {
1019 	struct {
1020 		struct chsc_header request;
1021 		u32 operation_code : 2;
1022 		u32 : 30;
1023 		u32 key : 4;
1024 		u32 : 28;
1025 		u32 zeroes1;
1026 		u32 cub_addr1;
1027 		u32 zeroes2;
1028 		u32 cub_addr2;
1029 		u32 reserved[13];
1030 		struct chsc_header response;
1031 		u32 status : 8;
1032 		u32 : 4;
1033 		u32 fmt : 4;
1034 		u32 : 16;
1035 	} __attribute__ ((packed)) *secm_area;
1036 	int ret, ccode;
1037 
1038 	secm_area = page;
1039 	secm_area->request.length = 0x0050;
1040 	secm_area->request.code = 0x0016;
1041 
1042 	secm_area->key = PAGE_DEFAULT_KEY;
1043 	secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1044 	secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1045 
1046 	secm_area->operation_code = enable ? 0 : 1;
1047 
1048 	ccode = chsc(secm_area);
1049 	if (ccode > 0)
1050 		return (ccode == 3) ? -ENODEV : -EBUSY;
1051 
1052 	switch (secm_area->response.code) {
1053 	case 0x0001: /* Success. */
1054 		ret = 0;
1055 		break;
1056 	case 0x0003: /* Invalid block. */
1057 	case 0x0007: /* Invalid format. */
1058 	case 0x0008: /* Other invalid block. */
1059 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1060 		ret = -EINVAL;
1061 		break;
1062 	case 0x0004: /* Command not provided in model. */
1063 		CIO_CRW_EVENT(2, "Model does not provide secm\n");
1064 		ret = -EOPNOTSUPP;
1065 		break;
1066 	case 0x0102: /* cub adresses incorrect */
1067 		CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1068 		ret = -EINVAL;
1069 		break;
1070 	case 0x0103: /* key error */
1071 		CIO_CRW_EVENT(2, "Access key error in secm\n");
1072 		ret = -EINVAL;
1073 		break;
1074 	case 0x0105: /* error while starting */
1075 		CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1076 		ret = -EIO;
1077 		break;
1078 	default:
1079 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1080 			      secm_area->response.code);
1081 		ret = -EIO;
1082 	}
1083 	return ret;
1084 }
1085 
1086 int
1087 chsc_secm(struct channel_subsystem *css, int enable)
1088 {
1089 	void  *secm_area;
1090 	int ret;
1091 
1092 	secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1093 	if (!secm_area)
1094 		return -ENOMEM;
1095 
1096 	mutex_lock(&css->mutex);
1097 	if (enable && !css->cm_enabled) {
1098 		css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1099 		css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1100 		if (!css->cub_addr1 || !css->cub_addr2) {
1101 			free_page((unsigned long)css->cub_addr1);
1102 			free_page((unsigned long)css->cub_addr2);
1103 			free_page((unsigned long)secm_area);
1104 			mutex_unlock(&css->mutex);
1105 			return -ENOMEM;
1106 		}
1107 	}
1108 	ret = __chsc_do_secm(css, enable, secm_area);
1109 	if (!ret) {
1110 		css->cm_enabled = enable;
1111 		if (css->cm_enabled) {
1112 			ret = chsc_add_cmg_attr(css);
1113 			if (ret) {
1114 				memset(secm_area, 0, PAGE_SIZE);
1115 				__chsc_do_secm(css, 0, secm_area);
1116 				css->cm_enabled = 0;
1117 			}
1118 		} else
1119 			chsc_remove_cmg_attr(css);
1120 	}
1121 	if (enable && !css->cm_enabled) {
1122 		free_page((unsigned long)css->cub_addr1);
1123 		free_page((unsigned long)css->cub_addr2);
1124 	}
1125 	mutex_unlock(&css->mutex);
1126 	free_page((unsigned long)secm_area);
1127 	return ret;
1128 }
1129 
1130 /*
1131  * Files for the channel path entries.
1132  */
1133 static ssize_t
1134 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1135 {
1136 	struct channel_path *chp = container_of(dev, struct channel_path, dev);
1137 
1138 	if (!chp)
1139 		return 0;
1140 	return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1141 		sprintf(buf, "offline\n"));
1142 }
1143 
1144 static ssize_t
1145 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1146 {
1147 	struct channel_path *cp = container_of(dev, struct channel_path, dev);
1148 	char cmd[10];
1149 	int num_args;
1150 	int error;
1151 
1152 	num_args = sscanf(buf, "%5s", cmd);
1153 	if (!num_args)
1154 		return count;
1155 
1156 	if (!strnicmp(cmd, "on", 2))
1157 		error = s390_vary_chpid(cp->id, 1);
1158 	else if (!strnicmp(cmd, "off", 3))
1159 		error = s390_vary_chpid(cp->id, 0);
1160 	else
1161 		error = -EINVAL;
1162 
1163 	return error < 0 ? error : count;
1164 
1165 }
1166 
1167 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1168 
1169 static ssize_t
1170 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1171 {
1172 	struct channel_path *chp = container_of(dev, struct channel_path, dev);
1173 
1174 	if (!chp)
1175 		return 0;
1176 	return sprintf(buf, "%x\n", chp->desc.desc);
1177 }
1178 
1179 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1180 
1181 static ssize_t
1182 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1183 {
1184 	struct channel_path *chp = to_channelpath(dev);
1185 
1186 	if (!chp)
1187 		return 0;
1188 	if (chp->cmg == -1) /* channel measurements not available */
1189 		return sprintf(buf, "unknown\n");
1190 	return sprintf(buf, "%x\n", chp->cmg);
1191 }
1192 
1193 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1194 
1195 static ssize_t
1196 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1197 {
1198 	struct channel_path *chp = to_channelpath(dev);
1199 
1200 	if (!chp)
1201 		return 0;
1202 	if (chp->shared == -1) /* channel measurements not available */
1203 		return sprintf(buf, "unknown\n");
1204 	return sprintf(buf, "%x\n", chp->shared);
1205 }
1206 
1207 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1208 
1209 static struct attribute * chp_attrs[] = {
1210 	&dev_attr_status.attr,
1211 	&dev_attr_type.attr,
1212 	&dev_attr_cmg.attr,
1213 	&dev_attr_shared.attr,
1214 	NULL,
1215 };
1216 
1217 static struct attribute_group chp_attr_group = {
1218 	.attrs = chp_attrs,
1219 };
1220 
1221 static void
1222 chp_release(struct device *dev)
1223 {
1224 	struct channel_path *cp;
1225 
1226 	cp = container_of(dev, struct channel_path, dev);
1227 	kfree(cp);
1228 }
1229 
1230 static int
1231 chsc_determine_channel_path_description(int chpid,
1232 					struct channel_path_desc *desc)
1233 {
1234 	int ccode, ret;
1235 
1236 	struct {
1237 		struct chsc_header request;
1238 		u32 : 24;
1239 		u32 first_chpid : 8;
1240 		u32 : 24;
1241 		u32 last_chpid : 8;
1242 		u32 zeroes1;
1243 		struct chsc_header response;
1244 		u32 zeroes2;
1245 		struct channel_path_desc desc;
1246 	} __attribute__ ((packed)) *scpd_area;
1247 
1248 	scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1249 	if (!scpd_area)
1250 		return -ENOMEM;
1251 
1252 	scpd_area->request.length = 0x0010;
1253 	scpd_area->request.code = 0x0002;
1254 
1255 	scpd_area->first_chpid = chpid;
1256 	scpd_area->last_chpid = chpid;
1257 
1258 	ccode = chsc(scpd_area);
1259 	if (ccode > 0) {
1260 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
1261 		goto out;
1262 	}
1263 
1264 	switch (scpd_area->response.code) {
1265 	case 0x0001: /* Success. */
1266 		memcpy(desc, &scpd_area->desc,
1267 		       sizeof(struct channel_path_desc));
1268 		ret = 0;
1269 		break;
1270 	case 0x0003: /* Invalid block. */
1271 	case 0x0007: /* Invalid format. */
1272 	case 0x0008: /* Other invalid block. */
1273 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1274 		ret = -EINVAL;
1275 		break;
1276 	case 0x0004: /* Command not provided in model. */
1277 		CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1278 		ret = -EOPNOTSUPP;
1279 		break;
1280 	default:
1281 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1282 			      scpd_area->response.code);
1283 		ret = -EIO;
1284 	}
1285 out:
1286 	free_page((unsigned long)scpd_area);
1287 	return ret;
1288 }
1289 
1290 static void
1291 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1292 			  struct cmg_chars *chars)
1293 {
1294 	switch (chp->cmg) {
1295 	case 2:
1296 	case 3:
1297 		chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1298 					 GFP_KERNEL);
1299 		if (chp->cmg_chars) {
1300 			int i, mask;
1301 			struct cmg_chars *cmg_chars;
1302 
1303 			cmg_chars = chp->cmg_chars;
1304 			for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1305 				mask = 0x80 >> (i + 3);
1306 				if (cmcv & mask)
1307 					cmg_chars->values[i] = chars->values[i];
1308 				else
1309 					cmg_chars->values[i] = 0;
1310 			}
1311 		}
1312 		break;
1313 	default:
1314 		/* No cmg-dependent data. */
1315 		break;
1316 	}
1317 }
1318 
1319 static int
1320 chsc_get_channel_measurement_chars(struct channel_path *chp)
1321 {
1322 	int ccode, ret;
1323 
1324 	struct {
1325 		struct chsc_header request;
1326 		u32 : 24;
1327 		u32 first_chpid : 8;
1328 		u32 : 24;
1329 		u32 last_chpid : 8;
1330 		u32 zeroes1;
1331 		struct chsc_header response;
1332 		u32 zeroes2;
1333 		u32 not_valid : 1;
1334 		u32 shared : 1;
1335 		u32 : 22;
1336 		u32 chpid : 8;
1337 		u32 cmcv : 5;
1338 		u32 : 11;
1339 		u32 cmgq : 8;
1340 		u32 cmg : 8;
1341 		u32 zeroes3;
1342 		u32 data[NR_MEASUREMENT_CHARS];
1343 	} __attribute__ ((packed)) *scmc_area;
1344 
1345 	scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1346 	if (!scmc_area)
1347 		return -ENOMEM;
1348 
1349 	scmc_area->request.length = 0x0010;
1350 	scmc_area->request.code = 0x0022;
1351 
1352 	scmc_area->first_chpid = chp->id;
1353 	scmc_area->last_chpid = chp->id;
1354 
1355 	ccode = chsc(scmc_area);
1356 	if (ccode > 0) {
1357 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
1358 		goto out;
1359 	}
1360 
1361 	switch (scmc_area->response.code) {
1362 	case 0x0001: /* Success. */
1363 		if (!scmc_area->not_valid) {
1364 			chp->cmg = scmc_area->cmg;
1365 			chp->shared = scmc_area->shared;
1366 			chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1367 						  (struct cmg_chars *)
1368 						  &scmc_area->data);
1369 		} else {
1370 			chp->cmg = -1;
1371 			chp->shared = -1;
1372 		}
1373 		ret = 0;
1374 		break;
1375 	case 0x0003: /* Invalid block. */
1376 	case 0x0007: /* Invalid format. */
1377 	case 0x0008: /* Invalid bit combination. */
1378 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1379 		ret = -EINVAL;
1380 		break;
1381 	case 0x0004: /* Command not provided. */
1382 		CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1383 		ret = -EOPNOTSUPP;
1384 		break;
1385 	default:
1386 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1387 			      scmc_area->response.code);
1388 		ret = -EIO;
1389 	}
1390 out:
1391 	free_page((unsigned long)scmc_area);
1392 	return ret;
1393 }
1394 
1395 /*
1396  * Entries for chpids on the system bus.
1397  * This replaces /proc/chpids.
1398  */
1399 static int
1400 new_channel_path(int chpid)
1401 {
1402 	struct channel_path *chp;
1403 	int ret;
1404 
1405 	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1406 	if (!chp)
1407 		return -ENOMEM;
1408 
1409 	/* fill in status, etc. */
1410 	chp->id = chpid;
1411 	chp->state = 1;
1412 	chp->dev.parent = &css[0]->device;
1413 	chp->dev.release = chp_release;
1414 	snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1415 
1416 	/* Obtain channel path description and fill it in. */
1417 	ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1418 	if (ret)
1419 		goto out_free;
1420 	/* Get channel-measurement characteristics. */
1421 	if (css_characteristics_avail && css_chsc_characteristics.scmc
1422 	    && css_chsc_characteristics.secm) {
1423 		ret = chsc_get_channel_measurement_chars(chp);
1424 		if (ret)
1425 			goto out_free;
1426 	} else {
1427 		static int msg_done;
1428 
1429 		if (!msg_done) {
1430 			printk(KERN_WARNING "cio: Channel measurements not "
1431 			       "available, continuing.\n");
1432 			msg_done = 1;
1433 		}
1434 		chp->cmg = -1;
1435 	}
1436 
1437 	/* make it known to the system */
1438 	ret = device_register(&chp->dev);
1439 	if (ret) {
1440 		printk(KERN_WARNING "%s: could not register %02x\n",
1441 		       __func__, chpid);
1442 		goto out_free;
1443 	}
1444 	ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1445 	if (ret) {
1446 		device_unregister(&chp->dev);
1447 		goto out_free;
1448 	}
1449 	mutex_lock(&css[0]->mutex);
1450 	if (css[0]->cm_enabled) {
1451 		ret = chsc_add_chp_cmg_attr(chp);
1452 		if (ret) {
1453 			sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1454 			device_unregister(&chp->dev);
1455 			mutex_unlock(&css[0]->mutex);
1456 			goto out_free;
1457 		}
1458 	}
1459 	css[0]->chps[chpid] = chp;
1460 	mutex_unlock(&css[0]->mutex);
1461 	return ret;
1462 out_free:
1463 	kfree(chp);
1464 	return ret;
1465 }
1466 
1467 void *
1468 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1469 {
1470 	struct channel_path *chp;
1471 	struct channel_path_desc *desc;
1472 
1473 	chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1474 	if (!chp)
1475 		return NULL;
1476 	desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1477 	if (!desc)
1478 		return NULL;
1479 	memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1480 	return desc;
1481 }
1482 
1483 static int __init
1484 chsc_alloc_sei_area(void)
1485 {
1486 	sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1487 	if (!sei_page)
1488 		printk(KERN_WARNING"Can't allocate page for processing of " \
1489 		       "chsc machine checks!\n");
1490 	return (sei_page ? 0 : -ENOMEM);
1491 }
1492 
1493 int __init
1494 chsc_enable_facility(int operation_code)
1495 {
1496 	int ret;
1497 	struct {
1498 		struct chsc_header request;
1499 		u8 reserved1:4;
1500 		u8 format:4;
1501 		u8 reserved2;
1502 		u16 operation_code;
1503 		u32 reserved3;
1504 		u32 reserved4;
1505 		u32 operation_data_area[252];
1506 		struct chsc_header response;
1507 		u32 reserved5:4;
1508 		u32 format2:4;
1509 		u32 reserved6:24;
1510 	} __attribute__ ((packed)) *sda_area;
1511 
1512 	sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1513 	if (!sda_area)
1514 		return -ENOMEM;
1515 	sda_area->request.length = 0x0400;
1516 	sda_area->request.code = 0x0031;
1517 	sda_area->operation_code = operation_code;
1518 
1519 	ret = chsc(sda_area);
1520 	if (ret > 0) {
1521 		ret = (ret == 3) ? -ENODEV : -EBUSY;
1522 		goto out;
1523 	}
1524 	switch (sda_area->response.code) {
1525 	case 0x0001: /* everything ok */
1526 		ret = 0;
1527 		break;
1528 	case 0x0003: /* invalid request block */
1529 	case 0x0007:
1530 		ret = -EINVAL;
1531 		break;
1532 	case 0x0004: /* command not provided */
1533 	case 0x0101: /* facility not provided */
1534 		ret = -EOPNOTSUPP;
1535 		break;
1536 	default: /* something went wrong */
1537 		ret = -EIO;
1538 	}
1539  out:
1540 	free_page((unsigned long)sda_area);
1541 	return ret;
1542 }
1543 
1544 subsys_initcall(chsc_alloc_sei_area);
1545 
1546 struct css_general_char css_general_characteristics;
1547 struct css_chsc_char css_chsc_characteristics;
1548 
1549 int __init
1550 chsc_determine_css_characteristics(void)
1551 {
1552 	int result;
1553 	struct {
1554 		struct chsc_header request;
1555 		u32 reserved1;
1556 		u32 reserved2;
1557 		u32 reserved3;
1558 		struct chsc_header response;
1559 		u32 reserved4;
1560 		u32 general_char[510];
1561 		u32 chsc_char[518];
1562 	} __attribute__ ((packed)) *scsc_area;
1563 
1564 	scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1565 	if (!scsc_area) {
1566 	        printk(KERN_WARNING"cio: Was not able to determine available" \
1567 		       "CHSCs due to no memory.\n");
1568 		return -ENOMEM;
1569 	}
1570 
1571 	scsc_area->request.length = 0x0010;
1572 	scsc_area->request.code = 0x0010;
1573 
1574 	result = chsc(scsc_area);
1575 	if (result) {
1576 		printk(KERN_WARNING"cio: Was not able to determine " \
1577 		       "available CHSCs, cc=%i.\n", result);
1578 		result = -EIO;
1579 		goto exit;
1580 	}
1581 
1582 	if (scsc_area->response.code != 1) {
1583 		printk(KERN_WARNING"cio: Was not able to determine " \
1584 		       "available CHSCs.\n");
1585 		result = -EIO;
1586 		goto exit;
1587 	}
1588 	memcpy(&css_general_characteristics, scsc_area->general_char,
1589 	       sizeof(css_general_characteristics));
1590 	memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1591 	       sizeof(css_chsc_characteristics));
1592 exit:
1593 	free_page ((unsigned long) scsc_area);
1594 	return result;
1595 }
1596 
1597 EXPORT_SYMBOL_GPL(css_general_characteristics);
1598 EXPORT_SYMBOL_GPL(css_chsc_characteristics);
1599