xref: /linux/drivers/s390/cio/chsc.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/device.h>
17 
18 #include <asm/cio.h>
19 
20 #include "css.h"
21 #include "cio.h"
22 #include "cio_debug.h"
23 #include "ioasm.h"
24 #include "chsc.h"
25 
26 static void *sei_page;
27 
28 static int new_channel_path(int chpid);
29 
30 static inline void
31 set_chp_logically_online(int chp, int onoff)
32 {
33 	css[0]->chps[chp]->state = onoff;
34 }
35 
36 static int
37 get_chp_status(int chp)
38 {
39 	return (css[0]->chps[chp] ? css[0]->chps[chp]->state : -ENODEV);
40 }
41 
42 void
43 chsc_validate_chpids(struct subchannel *sch)
44 {
45 	int mask, chp;
46 
47 	for (chp = 0; chp <= 7; chp++) {
48 		mask = 0x80 >> chp;
49 		if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
50 			/* disable using this path */
51 			sch->opm &= ~mask;
52 	}
53 }
54 
55 void
56 chpid_is_actually_online(int chp)
57 {
58 	int state;
59 
60 	state = get_chp_status(chp);
61 	if (state < 0) {
62 		need_rescan = 1;
63 		queue_work(slow_path_wq, &slow_path_work);
64 	} else
65 		WARN_ON(!state);
66 }
67 
68 /* FIXME: this is _always_ called for every subchannel. shouldn't we
69  *	  process more than one at a time? */
70 static int
71 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
72 {
73 	int ccode, j;
74 
75 	struct {
76 		struct chsc_header request;
77 		u16 reserved1a:10;
78 		u16 ssid:2;
79 		u16 reserved1b:4;
80 		u16 f_sch;	  /* first subchannel */
81 		u16 reserved2;
82 		u16 l_sch;	  /* last subchannel */
83 		u32 reserved3;
84 		struct chsc_header response;
85 		u32 reserved4;
86 		u8 sch_valid : 1;
87 		u8 dev_valid : 1;
88 		u8 st	     : 3; /* subchannel type */
89 		u8 zeroes    : 3;
90 		u8  unit_addr;	  /* unit address */
91 		u16 devno;	  /* device number */
92 		u8 path_mask;
93 		u8 fla_valid_mask;
94 		u16 sch;	  /* subchannel */
95 		u8 chpid[8];	  /* chpids 0-7 */
96 		u16 fla[8];	  /* full link addresses 0-7 */
97 	} *ssd_area;
98 
99 	ssd_area = page;
100 
101 	ssd_area->request.length = 0x0010;
102 	ssd_area->request.code = 0x0004;
103 
104 	ssd_area->ssid = sch->schid.ssid;
105 	ssd_area->f_sch = sch->schid.sch_no;
106 	ssd_area->l_sch = sch->schid.sch_no;
107 
108 	ccode = chsc(ssd_area);
109 	if (ccode > 0) {
110 		pr_debug("chsc returned with ccode = %d\n", ccode);
111 		return (ccode == 3) ? -ENODEV : -EBUSY;
112 	}
113 
114 	switch (ssd_area->response.code) {
115 	case 0x0001: /* everything ok */
116 		break;
117 	case 0x0002:
118 		CIO_CRW_EVENT(2, "Invalid command!\n");
119 		return -EINVAL;
120 	case 0x0003:
121 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
122 		return -EINVAL;
123 	case 0x0004:
124 		CIO_CRW_EVENT(2, "Model does not provide ssd\n");
125 		return -EOPNOTSUPP;
126 	default:
127 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
128 			      ssd_area->response.code);
129 		return -EIO;
130 	}
131 
132 	/*
133 	 * ssd_area->st stores the type of the detected
134 	 * subchannel, with the following definitions:
135 	 *
136 	 * 0: I/O subchannel:	  All fields have meaning
137 	 * 1: CHSC subchannel:	  Only sch_val, st and sch
138 	 *			  have meaning
139 	 * 2: Message subchannel: All fields except unit_addr
140 	 *			  have meaning
141 	 * 3: ADM subchannel:	  Only sch_val, st and sch
142 	 *			  have meaning
143 	 *
144 	 * Other types are currently undefined.
145 	 */
146 	if (ssd_area->st > 3) { /* uhm, that looks strange... */
147 		CIO_CRW_EVENT(0, "Strange subchannel type %d"
148 			      " for sch 0.%x.%04x\n", ssd_area->st,
149 			      sch->schid.ssid, sch->schid.sch_no);
150 		/*
151 		 * There may have been a new subchannel type defined in the
152 		 * time since this code was written; since we don't know which
153 		 * fields have meaning and what to do with it we just jump out
154 		 */
155 		return 0;
156 	} else {
157 		const char *type[4] = {"I/O", "chsc", "message", "ADM"};
158 		CIO_CRW_EVENT(6, "ssd: sch 0.%x.%04x is %s subchannel\n",
159 			      sch->schid.ssid, sch->schid.sch_no,
160 			      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 	struct channel_path *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->id)
228 			break;
229 	if (j >= 8)
230 		return 0;
231 
232 	mask = 0x80 >> j;
233 	spin_lock_irq(&sch->lock);
234 
235 	stsch(sch->schid, &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_DEVACT) &&
246 	    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
247 	    (sch->schib.pmcw.lpum == mask) &&
248 	    (sch->vpm == 0)) {
249 		int cc;
250 
251 		cc = cio_clear(sch);
252 		if (cc == -ENODEV)
253 			goto out_unreg;
254 		/* Call handler. */
255 		if (sch->driver && sch->driver->termination)
256 			sch->driver->termination(&sch->dev);
257 		goto out_unlock;
258 	}
259 
260 	/* trigger path verification. */
261 	if (sch->driver && sch->driver->verify)
262 		sch->driver->verify(&sch->dev);
263 out_unlock:
264 	spin_unlock_irq(&sch->lock);
265 	return 0;
266 out_unreg:
267 	spin_unlock_irq(&sch->lock);
268 	sch->lpm = 0;
269 	if (css_enqueue_subchannel_slow(sch->schid)) {
270 		css_clear_subchannel_slow_list();
271 		need_rescan = 1;
272 	}
273 	return 0;
274 }
275 
276 static inline void
277 s390_set_chpid_offline( __u8 chpid)
278 {
279 	char dbf_txt[15];
280 	struct device *dev;
281 
282 	sprintf(dbf_txt, "chpr%x", chpid);
283 	CIO_TRACE_EVENT(2, dbf_txt);
284 
285 	if (get_chp_status(chpid) <= 0)
286 		return;
287 	dev = get_device(&css[0]->chps[chpid]->dev);
288 	bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
289 			 s390_subchannel_remove_chpid);
290 
291 	if (need_rescan || css_slow_subchannels_exist())
292 		queue_work(slow_path_wq, &slow_path_work);
293 	put_device(dev);
294 }
295 
296 struct res_acc_data {
297 	struct channel_path *chp;
298 	u32 fla_mask;
299 	u16 fla;
300 };
301 
302 static int
303 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
304 {
305 	int found;
306 	int chp;
307 	int ccode;
308 
309 	found = 0;
310 	for (chp = 0; chp <= 7; chp++)
311 		/*
312 		 * check if chpid is in information updated by ssd
313 		 */
314 		if (sch->ssd_info.valid &&
315 		    sch->ssd_info.chpid[chp] == res_data->chp->id &&
316 		    (sch->ssd_info.fla[chp] & res_data->fla_mask)
317 		    == res_data->fla) {
318 			found = 1;
319 			break;
320 		}
321 
322 	if (found == 0)
323 		return 0;
324 
325 	/*
326 	 * Do a stsch to update our subchannel structure with the
327 	 * new path information and eventually check for logically
328 	 * offline chpids.
329 	 */
330 	ccode = stsch(sch->schid, &sch->schib);
331 	if (ccode > 0)
332 		return 0;
333 
334 	return 0x80 >> chp;
335 }
336 
337 static inline int
338 s390_process_res_acc_new_sch(struct subchannel_id schid)
339 {
340 	struct schib schib;
341 	int ret;
342 	/*
343 	 * We don't know the device yet, but since a path
344 	 * may be available now to the device we'll have
345 	 * to do recognition again.
346 	 * Since we don't have any idea about which chpid
347 	 * that beast may be on we'll have to do a stsch
348 	 * on all devices, grr...
349 	 */
350 	if (stsch_err(schid, &schib))
351 		/* We're through */
352 		return need_rescan ? -EAGAIN : -ENXIO;
353 
354 	/* Put it on the slow path. */
355 	ret = css_enqueue_subchannel_slow(schid);
356 	if (ret) {
357 		css_clear_subchannel_slow_list();
358 		need_rescan = 1;
359 		return -EAGAIN;
360 	}
361 	return 0;
362 }
363 
364 static int
365 __s390_process_res_acc(struct subchannel_id schid, void *data)
366 {
367 	int chp_mask, old_lpm;
368 	struct res_acc_data *res_data;
369 	struct subchannel *sch;
370 
371 	res_data = (struct res_acc_data *)data;
372 	sch = get_subchannel_by_schid(schid);
373 	if (!sch)
374 		/* Check if a subchannel is newly available. */
375 		return s390_process_res_acc_new_sch(schid);
376 
377 	spin_lock_irq(&sch->lock);
378 
379 	chp_mask = s390_process_res_acc_sch(res_data, sch);
380 
381 	if (chp_mask == 0) {
382 		spin_unlock_irq(&sch->lock);
383 		return 0;
384 	}
385 	old_lpm = sch->lpm;
386 	sch->lpm = ((sch->schib.pmcw.pim &
387 		     sch->schib.pmcw.pam &
388 		     sch->schib.pmcw.pom)
389 		    | chp_mask) & sch->opm;
390 	if (!old_lpm && sch->lpm)
391 		device_trigger_reprobe(sch);
392 	else if (sch->driver && sch->driver->verify)
393 		sch->driver->verify(&sch->dev);
394 
395 	spin_unlock_irq(&sch->lock);
396 	put_device(&sch->dev);
397 	return (res_data->fla_mask == 0xffff) ? -ENODEV : 0;
398 }
399 
400 
401 static int
402 s390_process_res_acc (struct res_acc_data *res_data)
403 {
404 	int rc;
405 	char dbf_txt[15];
406 
407 	sprintf(dbf_txt, "accpr%x", res_data->chp->id);
408 	CIO_TRACE_EVENT( 2, dbf_txt);
409 	if (res_data->fla != 0) {
410 		sprintf(dbf_txt, "fla%x", res_data->fla);
411 		CIO_TRACE_EVENT( 2, dbf_txt);
412 	}
413 
414 	/*
415 	 * I/O resources may have become accessible.
416 	 * Scan through all subchannels that may be concerned and
417 	 * do a validation on those.
418 	 * The more information we have (info), the less scanning
419 	 * will we have to do.
420 	 */
421 	rc = for_each_subchannel(__s390_process_res_acc, res_data);
422 	if (css_slow_subchannels_exist())
423 		rc = -EAGAIN;
424 	else if (rc != -EAGAIN)
425 		rc = 0;
426 	return rc;
427 }
428 
429 static int
430 __get_chpid_from_lir(void *data)
431 {
432 	struct lir {
433 		u8  iq;
434 		u8  ic;
435 		u16 sci;
436 		/* incident-node descriptor */
437 		u32 indesc[28];
438 		/* attached-node descriptor */
439 		u32 andesc[28];
440 		/* incident-specific information */
441 		u32 isinfo[28];
442 	} *lir;
443 
444 	lir = (struct lir*) data;
445 	if (!(lir->iq&0x80))
446 		/* NULL link incident record */
447 		return -EINVAL;
448 	if (!(lir->indesc[0]&0xc0000000))
449 		/* node descriptor not valid */
450 		return -EINVAL;
451 	if (!(lir->indesc[0]&0x10000000))
452 		/* don't handle device-type nodes - FIXME */
453 		return -EINVAL;
454 	/* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
455 
456 	return (u16) (lir->indesc[0]&0x000000ff);
457 }
458 
459 int
460 chsc_process_crw(void)
461 {
462 	int chpid, ret;
463 	struct res_acc_data res_data;
464 	struct {
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 		u32 ccdf[96];	/* content-code dependent field */
480 		/* ccdf has to be big enough for a link-incident record */
481 	} *sei_area;
482 
483 	if (!sei_page)
484 		return 0;
485 	/*
486 	 * build the chsc request block for store event information
487 	 * and do the call
488 	 * This function is only called by the machine check handler thread,
489 	 * so we don't need locking for the sei_page.
490 	 */
491 	sei_area = sei_page;
492 
493 	CIO_TRACE_EVENT( 2, "prcss");
494 	ret = 0;
495 	do {
496 		int ccode, status;
497 		struct device *dev;
498 		memset(sei_area, 0, sizeof(*sei_area));
499 		memset(&res_data, 0, sizeof(struct res_acc_data));
500 		sei_area->request.length = 0x0010;
501 		sei_area->request.code = 0x000e;
502 
503 		ccode = chsc(sei_area);
504 		if (ccode > 0)
505 			return 0;
506 
507 		switch (sei_area->response.code) {
508 			/* for debug purposes, check for problems */
509 		case 0x0001:
510 			CIO_CRW_EVENT(4, "chsc_process_crw: event information "
511 					"successfully stored\n");
512 			break; /* everything ok */
513 		case 0x0002:
514 			CIO_CRW_EVENT(2,
515 				      "chsc_process_crw: invalid command!\n");
516 			return 0;
517 		case 0x0003:
518 			CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
519 				      "request block!\n");
520 			return 0;
521 		case 0x0005:
522 			CIO_CRW_EVENT(2, "chsc_process_crw: no event "
523 				      "information stored\n");
524 			return 0;
525 		default:
526 			CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
527 				      sei_area->response.code);
528 			return 0;
529 		}
530 
531 		/* Check if we might have lost some information. */
532 		if (sei_area->flags & 0x40)
533 			CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
534 				       "has been lost due to overflow!\n");
535 
536 		if (sei_area->rs != 4) {
537 			CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
538 				      "(%04X) isn't a chpid!\n",
539 				      sei_area->rsid);
540 			continue;
541 		}
542 
543 		/* which kind of information was stored? */
544 		switch (sei_area->cc) {
545 		case 1: /* link incident*/
546 			CIO_CRW_EVENT(4, "chsc_process_crw: "
547 				      "channel subsystem reports link incident,"
548 				      " reporting source is chpid %x\n",
549 				      sei_area->rsid);
550 			chpid = __get_chpid_from_lir(sei_area->ccdf);
551 			if (chpid < 0)
552 				CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
553 					      __FUNCTION__);
554 			else
555 				s390_set_chpid_offline(chpid);
556 			break;
557 
558 		case 2: /* i/o resource accessibiliy */
559 			CIO_CRW_EVENT(4, "chsc_process_crw: "
560 				      "channel subsystem reports some I/O "
561 				      "devices may have become accessible\n");
562 			pr_debug("Data received after sei: \n");
563 			pr_debug("Validity flags: %x\n", sei_area->vf);
564 
565 			/* allocate a new channel path structure, if needed */
566 			status = get_chp_status(sei_area->rsid);
567 			if (status < 0)
568 				new_channel_path(sei_area->rsid);
569 			else if (!status)
570 				break;
571 			dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
572 			res_data.chp = to_channelpath(dev);
573 			pr_debug("chpid: %x", sei_area->rsid);
574 			if ((sei_area->vf & 0xc0) != 0) {
575 				res_data.fla = sei_area->fla;
576 				if ((sei_area->vf & 0xc0) == 0xc0) {
577 					pr_debug(" full link addr: %x",
578 						 sei_area->fla);
579 					res_data.fla_mask = 0xffff;
580 				} else {
581 					pr_debug(" link addr: %x",
582 						 sei_area->fla);
583 					res_data.fla_mask = 0xff00;
584 				}
585 			}
586 			ret = s390_process_res_acc(&res_data);
587 			pr_debug("\n\n");
588 			put_device(dev);
589 			break;
590 
591 		default: /* other stuff */
592 			CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
593 				      sei_area->cc);
594 			break;
595 		}
596 	} while (sei_area->flags & 0x80);
597 	return ret;
598 }
599 
600 static inline int
601 __chp_add_new_sch(struct subchannel_id schid)
602 {
603 	struct schib schib;
604 	int ret;
605 
606 	if (stsch(schid, &schib))
607 		/* We're through */
608 		return need_rescan ? -EAGAIN : -ENXIO;
609 
610 	/* Put it on the slow path. */
611 	ret = css_enqueue_subchannel_slow(schid);
612 	if (ret) {
613 		css_clear_subchannel_slow_list();
614 		need_rescan = 1;
615 		return -EAGAIN;
616 	}
617 	return 0;
618 }
619 
620 
621 static int
622 __chp_add(struct subchannel_id schid, void *data)
623 {
624 	int i;
625 	struct channel_path *chp;
626 	struct subchannel *sch;
627 
628 	chp = (struct channel_path *)data;
629 	sch = get_subchannel_by_schid(schid);
630 	if (!sch)
631 		/* Check if the subchannel is now available. */
632 		return __chp_add_new_sch(schid);
633 	spin_lock_irq(&sch->lock);
634 	for (i=0; i<8; i++)
635 		if (sch->schib.pmcw.chpid[i] == chp->id) {
636 			if (stsch(sch->schid, &sch->schib) != 0) {
637 				/* Endgame. */
638 				spin_unlock_irq(&sch->lock);
639 				return -ENXIO;
640 			}
641 			break;
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 		    | 0x80 >> i) & 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 inline int
705 __check_for_io_and_kill(struct subchannel *sch, int index)
706 {
707 	int cc;
708 
709 	if (!device_is_online(sch))
710 		/* cio could be doing I/O. */
711 		return 0;
712 	cc = stsch(sch->schid, &sch->schib);
713 	if (cc)
714 		return 0;
715 	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
716 		device_set_waiting(sch);
717 		return 1;
718 	}
719 	return 0;
720 }
721 
722 static inline void
723 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
724 {
725 	int chp, old_lpm;
726 	unsigned long flags;
727 
728 	if (!sch->ssd_info.valid)
729 		return;
730 
731 	spin_lock_irqsave(&sch->lock, flags);
732 	old_lpm = sch->lpm;
733 	for (chp = 0; chp < 8; chp++) {
734 		if (sch->ssd_info.chpid[chp] != chpid)
735 			continue;
736 
737 		if (on) {
738 			sch->opm |= (0x80 >> chp);
739 			sch->lpm |= (0x80 >> chp);
740 			if (!old_lpm)
741 				device_trigger_reprobe(sch);
742 			else if (sch->driver && sch->driver->verify)
743 				sch->driver->verify(&sch->dev);
744 		} else {
745 			sch->opm &= ~(0x80 >> chp);
746 			sch->lpm &= ~(0x80 >> chp);
747 			/*
748 			 * Give running I/O a grace period in which it
749 			 * can successfully terminate, even using the
750 			 * just varied off path. Then kill it.
751 			 */
752 			if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
753 				if (css_enqueue_subchannel_slow(sch->schid)) {
754 					css_clear_subchannel_slow_list();
755 					need_rescan = 1;
756 				}
757 			} else if (sch->driver && sch->driver->verify)
758 				sch->driver->verify(&sch->dev);
759 		}
760 		break;
761 	}
762 	spin_unlock_irqrestore(&sch->lock, flags);
763 }
764 
765 static int
766 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
767 {
768 	struct subchannel *sch;
769 	__u8 *chpid;
770 
771 	sch = to_subchannel(dev);
772 	chpid = data;
773 
774 	__s390_subchannel_vary_chpid(sch, *chpid, 0);
775 	return 0;
776 }
777 
778 static int
779 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
780 {
781 	struct subchannel *sch;
782 	__u8 *chpid;
783 
784 	sch = to_subchannel(dev);
785 	chpid = data;
786 
787 	__s390_subchannel_vary_chpid(sch, *chpid, 1);
788 	return 0;
789 }
790 
791 static int
792 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
793 {
794 	struct schib schib;
795 	struct subchannel *sch;
796 
797 	sch = get_subchannel_by_schid(schid);
798 	if (sch) {
799 		put_device(&sch->dev);
800 		return 0;
801 	}
802 	if (stsch_err(schid, &schib))
803 		/* We're through */
804 		return -ENXIO;
805 	/* Put it on the slow path. */
806 	if (css_enqueue_subchannel_slow(schid)) {
807 		css_clear_subchannel_slow_list();
808 		need_rescan = 1;
809 		return -EAGAIN;
810 	}
811 	return 0;
812 }
813 
814 /*
815  * Function: s390_vary_chpid
816  * Varies the specified chpid online or offline
817  */
818 static int
819 s390_vary_chpid( __u8 chpid, int on)
820 {
821 	char dbf_text[15];
822 	int status;
823 
824 	sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
825 	CIO_TRACE_EVENT( 2, dbf_text);
826 
827 	status = get_chp_status(chpid);
828 	if (status < 0) {
829 		printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
830 		return -EINVAL;
831 	}
832 
833 	if (!on && !status) {
834 		printk(KERN_ERR "chpid %x is already offline\n", chpid);
835 		return -EINVAL;
836 	}
837 
838 	set_chp_logically_online(chpid, on);
839 
840 	/*
841 	 * Redo PathVerification on the devices the chpid connects to
842 	 */
843 
844 	bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
845 			 s390_subchannel_vary_chpid_on :
846 			 s390_subchannel_vary_chpid_off);
847 	if (on)
848 		/* Scan for new devices on varied on path. */
849 		for_each_subchannel(__s390_vary_chpid_on, NULL);
850 	if (need_rescan || css_slow_subchannels_exist())
851 		queue_work(slow_path_wq, &slow_path_work);
852 	return 0;
853 }
854 
855 /*
856  * Channel measurement related functions
857  */
858 static ssize_t
859 chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
860 			   size_t count)
861 {
862 	struct channel_path *chp;
863 	unsigned int size;
864 
865 	chp = to_channelpath(container_of(kobj, struct device, kobj));
866 	if (!chp->cmg_chars)
867 		return 0;
868 
869 	size = sizeof(struct cmg_chars);
870 
871 	if (off > size)
872 		return 0;
873 	if (off + count > size)
874 		count = size - off;
875 	memcpy(buf, chp->cmg_chars + off, count);
876 	return count;
877 }
878 
879 static struct bin_attribute chp_measurement_chars_attr = {
880 	.attr = {
881 		.name = "measurement_chars",
882 		.mode = S_IRUSR,
883 		.owner = THIS_MODULE,
884 	},
885 	.size = sizeof(struct cmg_chars),
886 	.read = chp_measurement_chars_read,
887 };
888 
889 static void
890 chp_measurement_copy_block(struct cmg_entry *buf,
891 			   struct channel_subsystem *css, int chpid)
892 {
893 	void *area;
894 	struct cmg_entry *entry, reference_buf;
895 	int idx;
896 
897 	if (chpid < 128) {
898 		area = css->cub_addr1;
899 		idx = chpid;
900 	} else {
901 		area = css->cub_addr2;
902 		idx = chpid - 128;
903 	}
904 	entry = area + (idx * sizeof(struct cmg_entry));
905 	do {
906 		memcpy(buf, entry, sizeof(*entry));
907 		memcpy(&reference_buf, entry, sizeof(*entry));
908 	} while (reference_buf.values[0] != buf->values[0]);
909 }
910 
911 static ssize_t
912 chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
913 {
914 	struct channel_path *chp;
915 	struct channel_subsystem *css;
916 	unsigned int size;
917 
918 	chp = to_channelpath(container_of(kobj, struct device, kobj));
919 	css = to_css(chp->dev.parent);
920 
921 	size = sizeof(struct cmg_chars);
922 
923 	/* Only allow single reads. */
924 	if (off || count < size)
925 		return 0;
926 	chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
927 	return count;
928 }
929 
930 static struct bin_attribute chp_measurement_attr = {
931 	.attr = {
932 		.name = "measurement",
933 		.mode = S_IRUSR,
934 		.owner = THIS_MODULE,
935 	},
936 	.size = sizeof(struct cmg_entry),
937 	.read = chp_measurement_read,
938 };
939 
940 static void
941 chsc_remove_chp_cmg_attr(struct channel_path *chp)
942 {
943 	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
944 	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
945 }
946 
947 static int
948 chsc_add_chp_cmg_attr(struct channel_path *chp)
949 {
950 	int ret;
951 
952 	ret = sysfs_create_bin_file(&chp->dev.kobj,
953 				    &chp_measurement_chars_attr);
954 	if (ret)
955 		return ret;
956 	ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
957 	if (ret)
958 		sysfs_remove_bin_file(&chp->dev.kobj,
959 				      &chp_measurement_chars_attr);
960 	return ret;
961 }
962 
963 static void
964 chsc_remove_cmg_attr(struct channel_subsystem *css)
965 {
966 	int i;
967 
968 	for (i = 0; i <= __MAX_CHPID; i++) {
969 		if (!css->chps[i])
970 			continue;
971 		chsc_remove_chp_cmg_attr(css->chps[i]);
972 	}
973 }
974 
975 static int
976 chsc_add_cmg_attr(struct channel_subsystem *css)
977 {
978 	int i, ret;
979 
980 	ret = 0;
981 	for (i = 0; i <= __MAX_CHPID; i++) {
982 		if (!css->chps[i])
983 			continue;
984 		ret = chsc_add_chp_cmg_attr(css->chps[i]);
985 		if (ret)
986 			goto cleanup;
987 	}
988 	return ret;
989 cleanup:
990 	for (--i; i >= 0; i--) {
991 		if (!css->chps[i])
992 			continue;
993 		chsc_remove_chp_cmg_attr(css->chps[i]);
994 	}
995 	return ret;
996 }
997 
998 
999 static int
1000 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1001 {
1002 	struct {
1003 		struct chsc_header request;
1004 		u32 operation_code : 2;
1005 		u32 : 30;
1006 		u32 key : 4;
1007 		u32 : 28;
1008 		u32 zeroes1;
1009 		u32 cub_addr1;
1010 		u32 zeroes2;
1011 		u32 cub_addr2;
1012 		u32 reserved[13];
1013 		struct chsc_header response;
1014 		u32 status : 8;
1015 		u32 : 4;
1016 		u32 fmt : 4;
1017 		u32 : 16;
1018 	} *secm_area;
1019 	int ret, ccode;
1020 
1021 	secm_area = page;
1022 	secm_area->request.length = 0x0050;
1023 	secm_area->request.code = 0x0016;
1024 
1025 	secm_area->key = PAGE_DEFAULT_KEY;
1026 	secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1027 	secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1028 
1029 	secm_area->operation_code = enable ? 0 : 1;
1030 
1031 	ccode = chsc(secm_area);
1032 	if (ccode > 0)
1033 		return (ccode == 3) ? -ENODEV : -EBUSY;
1034 
1035 	switch (secm_area->response.code) {
1036 	case 0x0001: /* Success. */
1037 		ret = 0;
1038 		break;
1039 	case 0x0003: /* Invalid block. */
1040 	case 0x0007: /* Invalid format. */
1041 	case 0x0008: /* Other invalid block. */
1042 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1043 		ret = -EINVAL;
1044 		break;
1045 	case 0x0004: /* Command not provided in model. */
1046 		CIO_CRW_EVENT(2, "Model does not provide secm\n");
1047 		ret = -EOPNOTSUPP;
1048 		break;
1049 	case 0x0102: /* cub adresses incorrect */
1050 		CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1051 		ret = -EINVAL;
1052 		break;
1053 	case 0x0103: /* key error */
1054 		CIO_CRW_EVENT(2, "Access key error in secm\n");
1055 		ret = -EINVAL;
1056 		break;
1057 	case 0x0105: /* error while starting */
1058 		CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1059 		ret = -EIO;
1060 		break;
1061 	default:
1062 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1063 			      secm_area->response.code);
1064 		ret = -EIO;
1065 	}
1066 	return ret;
1067 }
1068 
1069 int
1070 chsc_secm(struct channel_subsystem *css, int enable)
1071 {
1072 	void  *secm_area;
1073 	int ret;
1074 
1075 	secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1076 	if (!secm_area)
1077 		return -ENOMEM;
1078 
1079 	mutex_lock(&css->mutex);
1080 	if (enable && !css->cm_enabled) {
1081 		css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1082 		css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1083 		if (!css->cub_addr1 || !css->cub_addr2) {
1084 			free_page((unsigned long)css->cub_addr1);
1085 			free_page((unsigned long)css->cub_addr2);
1086 			free_page((unsigned long)secm_area);
1087 			mutex_unlock(&css->mutex);
1088 			return -ENOMEM;
1089 		}
1090 	}
1091 	ret = __chsc_do_secm(css, enable, secm_area);
1092 	if (!ret) {
1093 		css->cm_enabled = enable;
1094 		if (css->cm_enabled) {
1095 			ret = chsc_add_cmg_attr(css);
1096 			if (ret) {
1097 				memset(secm_area, 0, PAGE_SIZE);
1098 				__chsc_do_secm(css, 0, secm_area);
1099 				css->cm_enabled = 0;
1100 			}
1101 		} else
1102 			chsc_remove_cmg_attr(css);
1103 	}
1104 	if (enable && !css->cm_enabled) {
1105 		free_page((unsigned long)css->cub_addr1);
1106 		free_page((unsigned long)css->cub_addr2);
1107 	}
1108 	mutex_unlock(&css->mutex);
1109 	free_page((unsigned long)secm_area);
1110 	return ret;
1111 }
1112 
1113 /*
1114  * Files for the channel path entries.
1115  */
1116 static ssize_t
1117 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1118 {
1119 	struct channel_path *chp = container_of(dev, struct channel_path, dev);
1120 
1121 	if (!chp)
1122 		return 0;
1123 	return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1124 		sprintf(buf, "offline\n"));
1125 }
1126 
1127 static ssize_t
1128 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1129 {
1130 	struct channel_path *cp = container_of(dev, struct channel_path, dev);
1131 	char cmd[10];
1132 	int num_args;
1133 	int error;
1134 
1135 	num_args = sscanf(buf, "%5s", cmd);
1136 	if (!num_args)
1137 		return count;
1138 
1139 	if (!strnicmp(cmd, "on", 2))
1140 		error = s390_vary_chpid(cp->id, 1);
1141 	else if (!strnicmp(cmd, "off", 3))
1142 		error = s390_vary_chpid(cp->id, 0);
1143 	else
1144 		error = -EINVAL;
1145 
1146 	return error < 0 ? error : count;
1147 
1148 }
1149 
1150 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1151 
1152 static ssize_t
1153 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1154 {
1155 	struct channel_path *chp = container_of(dev, struct channel_path, dev);
1156 
1157 	if (!chp)
1158 		return 0;
1159 	return sprintf(buf, "%x\n", chp->desc.desc);
1160 }
1161 
1162 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1163 
1164 static ssize_t
1165 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1166 {
1167 	struct channel_path *chp = to_channelpath(dev);
1168 
1169 	if (!chp)
1170 		return 0;
1171 	if (chp->cmg == -1) /* channel measurements not available */
1172 		return sprintf(buf, "unknown\n");
1173 	return sprintf(buf, "%x\n", chp->cmg);
1174 }
1175 
1176 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1177 
1178 static ssize_t
1179 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1180 {
1181 	struct channel_path *chp = to_channelpath(dev);
1182 
1183 	if (!chp)
1184 		return 0;
1185 	if (chp->shared == -1) /* channel measurements not available */
1186 		return sprintf(buf, "unknown\n");
1187 	return sprintf(buf, "%x\n", chp->shared);
1188 }
1189 
1190 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1191 
1192 static struct attribute * chp_attrs[] = {
1193 	&dev_attr_status.attr,
1194 	&dev_attr_type.attr,
1195 	&dev_attr_cmg.attr,
1196 	&dev_attr_shared.attr,
1197 	NULL,
1198 };
1199 
1200 static struct attribute_group chp_attr_group = {
1201 	.attrs = chp_attrs,
1202 };
1203 
1204 static void
1205 chp_release(struct device *dev)
1206 {
1207 	struct channel_path *cp;
1208 
1209 	cp = container_of(dev, struct channel_path, dev);
1210 	kfree(cp);
1211 }
1212 
1213 static int
1214 chsc_determine_channel_path_description(int chpid,
1215 					struct channel_path_desc *desc)
1216 {
1217 	int ccode, ret;
1218 
1219 	struct {
1220 		struct chsc_header request;
1221 		u32 : 24;
1222 		u32 first_chpid : 8;
1223 		u32 : 24;
1224 		u32 last_chpid : 8;
1225 		u32 zeroes1;
1226 		struct chsc_header response;
1227 		u32 zeroes2;
1228 		struct channel_path_desc desc;
1229 	} *scpd_area;
1230 
1231 	scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1232 	if (!scpd_area)
1233 		return -ENOMEM;
1234 
1235 	scpd_area->request.length = 0x0010;
1236 	scpd_area->request.code = 0x0002;
1237 
1238 	scpd_area->first_chpid = chpid;
1239 	scpd_area->last_chpid = chpid;
1240 
1241 	ccode = chsc(scpd_area);
1242 	if (ccode > 0) {
1243 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
1244 		goto out;
1245 	}
1246 
1247 	switch (scpd_area->response.code) {
1248 	case 0x0001: /* Success. */
1249 		memcpy(desc, &scpd_area->desc,
1250 		       sizeof(struct channel_path_desc));
1251 		ret = 0;
1252 		break;
1253 	case 0x0003: /* Invalid block. */
1254 	case 0x0007: /* Invalid format. */
1255 	case 0x0008: /* Other invalid block. */
1256 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1257 		ret = -EINVAL;
1258 		break;
1259 	case 0x0004: /* Command not provided in model. */
1260 		CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1261 		ret = -EOPNOTSUPP;
1262 		break;
1263 	default:
1264 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1265 			      scpd_area->response.code);
1266 		ret = -EIO;
1267 	}
1268 out:
1269 	free_page((unsigned long)scpd_area);
1270 	return ret;
1271 }
1272 
1273 static void
1274 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1275 			  struct cmg_chars *chars)
1276 {
1277 	switch (chp->cmg) {
1278 	case 2:
1279 	case 3:
1280 		chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1281 					 GFP_KERNEL);
1282 		if (chp->cmg_chars) {
1283 			int i, mask;
1284 			struct cmg_chars *cmg_chars;
1285 
1286 			cmg_chars = chp->cmg_chars;
1287 			for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1288 				mask = 0x80 >> (i + 3);
1289 				if (cmcv & mask)
1290 					cmg_chars->values[i] = chars->values[i];
1291 				else
1292 					cmg_chars->values[i] = 0;
1293 			}
1294 		}
1295 		break;
1296 	default:
1297 		/* No cmg-dependent data. */
1298 		break;
1299 	}
1300 }
1301 
1302 static int
1303 chsc_get_channel_measurement_chars(struct channel_path *chp)
1304 {
1305 	int ccode, ret;
1306 
1307 	struct {
1308 		struct chsc_header request;
1309 		u32 : 24;
1310 		u32 first_chpid : 8;
1311 		u32 : 24;
1312 		u32 last_chpid : 8;
1313 		u32 zeroes1;
1314 		struct chsc_header response;
1315 		u32 zeroes2;
1316 		u32 not_valid : 1;
1317 		u32 shared : 1;
1318 		u32 : 22;
1319 		u32 chpid : 8;
1320 		u32 cmcv : 5;
1321 		u32 : 11;
1322 		u32 cmgq : 8;
1323 		u32 cmg : 8;
1324 		u32 zeroes3;
1325 		u32 data[NR_MEASUREMENT_CHARS];
1326 	} *scmc_area;
1327 
1328 	scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1329 	if (!scmc_area)
1330 		return -ENOMEM;
1331 
1332 	scmc_area->request.length = 0x0010;
1333 	scmc_area->request.code = 0x0022;
1334 
1335 	scmc_area->first_chpid = chp->id;
1336 	scmc_area->last_chpid = chp->id;
1337 
1338 	ccode = chsc(scmc_area);
1339 	if (ccode > 0) {
1340 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
1341 		goto out;
1342 	}
1343 
1344 	switch (scmc_area->response.code) {
1345 	case 0x0001: /* Success. */
1346 		if (!scmc_area->not_valid) {
1347 			chp->cmg = scmc_area->cmg;
1348 			chp->shared = scmc_area->shared;
1349 			chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1350 						  (struct cmg_chars *)
1351 						  &scmc_area->data);
1352 		} else {
1353 			chp->cmg = -1;
1354 			chp->shared = -1;
1355 		}
1356 		ret = 0;
1357 		break;
1358 	case 0x0003: /* Invalid block. */
1359 	case 0x0007: /* Invalid format. */
1360 	case 0x0008: /* Invalid bit combination. */
1361 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1362 		ret = -EINVAL;
1363 		break;
1364 	case 0x0004: /* Command not provided. */
1365 		CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1366 		ret = -EOPNOTSUPP;
1367 		break;
1368 	default:
1369 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1370 			      scmc_area->response.code);
1371 		ret = -EIO;
1372 	}
1373 out:
1374 	free_page((unsigned long)scmc_area);
1375 	return ret;
1376 }
1377 
1378 /*
1379  * Entries for chpids on the system bus.
1380  * This replaces /proc/chpids.
1381  */
1382 static int
1383 new_channel_path(int chpid)
1384 {
1385 	struct channel_path *chp;
1386 	int ret;
1387 
1388 	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1389 	if (!chp)
1390 		return -ENOMEM;
1391 
1392 	/* fill in status, etc. */
1393 	chp->id = chpid;
1394 	chp->state = 1;
1395 	chp->dev = (struct device) {
1396 		.parent  = &css[0]->device,
1397 		.release = chp_release,
1398 	};
1399 	snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1400 
1401 	/* Obtain channel path description and fill it in. */
1402 	ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1403 	if (ret)
1404 		goto out_free;
1405 	/* Get channel-measurement characteristics. */
1406 	if (css_characteristics_avail && css_chsc_characteristics.scmc
1407 	    && css_chsc_characteristics.secm) {
1408 		ret = chsc_get_channel_measurement_chars(chp);
1409 		if (ret)
1410 			goto out_free;
1411 	} else {
1412 		static int msg_done;
1413 
1414 		if (!msg_done) {
1415 			printk(KERN_WARNING "cio: Channel measurements not "
1416 			       "available, continuing.\n");
1417 			msg_done = 1;
1418 		}
1419 		chp->cmg = -1;
1420 	}
1421 
1422 	/* make it known to the system */
1423 	ret = device_register(&chp->dev);
1424 	if (ret) {
1425 		printk(KERN_WARNING "%s: could not register %02x\n",
1426 		       __func__, chpid);
1427 		goto out_free;
1428 	}
1429 	ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1430 	if (ret) {
1431 		device_unregister(&chp->dev);
1432 		goto out_free;
1433 	}
1434 	mutex_lock(&css[0]->mutex);
1435 	if (css[0]->cm_enabled) {
1436 		ret = chsc_add_chp_cmg_attr(chp);
1437 		if (ret) {
1438 			sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1439 			device_unregister(&chp->dev);
1440 			mutex_unlock(&css[0]->mutex);
1441 			goto out_free;
1442 		}
1443 	}
1444 	css[0]->chps[chpid] = chp;
1445 	mutex_unlock(&css[0]->mutex);
1446 	return ret;
1447 out_free:
1448 	kfree(chp);
1449 	return ret;
1450 }
1451 
1452 void *
1453 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1454 {
1455 	struct channel_path *chp;
1456 	struct channel_path_desc *desc;
1457 
1458 	chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1459 	if (!chp)
1460 		return NULL;
1461 	desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1462 	if (!desc)
1463 		return NULL;
1464 	memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1465 	return desc;
1466 }
1467 
1468 
1469 static int __init
1470 chsc_alloc_sei_area(void)
1471 {
1472 	sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1473 	if (!sei_page)
1474 		printk(KERN_WARNING"Can't allocate page for processing of " \
1475 		       "chsc machine checks!\n");
1476 	return (sei_page ? 0 : -ENOMEM);
1477 }
1478 
1479 int __init
1480 chsc_enable_facility(int operation_code)
1481 {
1482 	int ret;
1483 	struct {
1484 		struct chsc_header request;
1485 		u8 reserved1:4;
1486 		u8 format:4;
1487 		u8 reserved2;
1488 		u16 operation_code;
1489 		u32 reserved3;
1490 		u32 reserved4;
1491 		u32 operation_data_area[252];
1492 		struct chsc_header response;
1493 		u32 reserved5:4;
1494 		u32 format2:4;
1495 		u32 reserved6:24;
1496 	} *sda_area;
1497 
1498 	sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1499 	if (!sda_area)
1500 		return -ENOMEM;
1501 	sda_area->request.length = 0x0400;
1502 	sda_area->request.code = 0x0031;
1503 	sda_area->operation_code = operation_code;
1504 
1505 	ret = chsc(sda_area);
1506 	if (ret > 0) {
1507 		ret = (ret == 3) ? -ENODEV : -EBUSY;
1508 		goto out;
1509 	}
1510 	switch (sda_area->response.code) {
1511 	case 0x0001: /* everything ok */
1512 		ret = 0;
1513 		break;
1514 	case 0x0003: /* invalid request block */
1515 	case 0x0007:
1516 		ret = -EINVAL;
1517 		break;
1518 	case 0x0004: /* command not provided */
1519 	case 0x0101: /* facility not provided */
1520 		ret = -EOPNOTSUPP;
1521 		break;
1522 	default: /* something went wrong */
1523 		ret = -EIO;
1524 	}
1525  out:
1526 	free_page((unsigned long)sda_area);
1527 	return ret;
1528 }
1529 
1530 subsys_initcall(chsc_alloc_sei_area);
1531 
1532 struct css_general_char css_general_characteristics;
1533 struct css_chsc_char css_chsc_characteristics;
1534 
1535 int __init
1536 chsc_determine_css_characteristics(void)
1537 {
1538 	int result;
1539 	struct {
1540 		struct chsc_header request;
1541 		u32 reserved1;
1542 		u32 reserved2;
1543 		u32 reserved3;
1544 		struct chsc_header response;
1545 		u32 reserved4;
1546 		u32 general_char[510];
1547 		u32 chsc_char[518];
1548 	} *scsc_area;
1549 
1550 	scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1551 	if (!scsc_area) {
1552 	        printk(KERN_WARNING"cio: Was not able to determine available" \
1553 		       "CHSCs due to no memory.\n");
1554 		return -ENOMEM;
1555 	}
1556 
1557 	scsc_area->request.length = 0x0010;
1558 	scsc_area->request.code = 0x0010;
1559 
1560 	result = chsc(scsc_area);
1561 	if (result) {
1562 		printk(KERN_WARNING"cio: Was not able to determine " \
1563 		       "available CHSCs, cc=%i.\n", result);
1564 		result = -EIO;
1565 		goto exit;
1566 	}
1567 
1568 	if (scsc_area->response.code != 1) {
1569 		printk(KERN_WARNING"cio: Was not able to determine " \
1570 		       "available CHSCs.\n");
1571 		result = -EIO;
1572 		goto exit;
1573 	}
1574 	memcpy(&css_general_characteristics, scsc_area->general_char,
1575 	       sizeof(css_general_characteristics));
1576 	memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1577 	       sizeof(css_chsc_characteristics));
1578 exit:
1579 	free_page ((unsigned long) scsc_area);
1580 	return result;
1581 }
1582 
1583 EXPORT_SYMBOL_GPL(css_general_characteristics);
1584 EXPORT_SYMBOL_GPL(css_chsc_characteristics);
1585