xref: /linux/drivers/s390/cio/chsc.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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_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_irq(&sch->lock);
283 	return 0;
284 out_unreg:
285 	spin_unlock_irq(&sch->lock);
286 	sch->lpm = 0;
287 	if (css_enqueue_subchannel_slow(sch->schid)) {
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 	struct device *dev;
299 
300 	sprintf(dbf_txt, "chpr%x", chpid);
301 	CIO_TRACE_EVENT(2, dbf_txt);
302 
303 	if (get_chp_status(chpid) <= 0)
304 		return;
305 	dev = get_device(&css[0]->chps[chpid]->dev);
306 	bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
307 			 s390_subchannel_remove_chpid);
308 
309 	if (need_rescan || css_slow_subchannels_exist())
310 		queue_work(slow_path_wq, &slow_path_work);
311 	put_device(dev);
312 }
313 
314 struct res_acc_data {
315 	struct channel_path *chp;
316 	u32 fla_mask;
317 	u16 fla;
318 };
319 
320 static int
321 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
322 {
323 	int found;
324 	int chp;
325 	int ccode;
326 
327 	found = 0;
328 	for (chp = 0; chp <= 7; chp++)
329 		/*
330 		 * check if chpid is in information updated by ssd
331 		 */
332 		if (sch->ssd_info.valid &&
333 		    sch->ssd_info.chpid[chp] == res_data->chp->id &&
334 		    (sch->ssd_info.fla[chp] & res_data->fla_mask)
335 		    == res_data->fla) {
336 			found = 1;
337 			break;
338 		}
339 
340 	if (found == 0)
341 		return 0;
342 
343 	/*
344 	 * Do a stsch to update our subchannel structure with the
345 	 * new path information and eventually check for logically
346 	 * offline chpids.
347 	 */
348 	ccode = stsch(sch->schid, &sch->schib);
349 	if (ccode > 0)
350 		return 0;
351 
352 	return 0x80 >> chp;
353 }
354 
355 static inline int
356 s390_process_res_acc_new_sch(struct subchannel_id schid)
357 {
358 	struct schib schib;
359 	int ret;
360 	/*
361 	 * We don't know the device yet, but since a path
362 	 * may be available now to the device we'll have
363 	 * to do recognition again.
364 	 * Since we don't have any idea about which chpid
365 	 * that beast may be on we'll have to do a stsch
366 	 * on all devices, grr...
367 	 */
368 	if (stsch_err(schid, &schib))
369 		/* We're through */
370 		return need_rescan ? -EAGAIN : -ENXIO;
371 
372 	/* Put it on the slow path. */
373 	ret = css_enqueue_subchannel_slow(schid);
374 	if (ret) {
375 		css_clear_subchannel_slow_list();
376 		need_rescan = 1;
377 		return -EAGAIN;
378 	}
379 	return 0;
380 }
381 
382 static int
383 __s390_process_res_acc(struct subchannel_id schid, void *data)
384 {
385 	int chp_mask, old_lpm;
386 	struct res_acc_data *res_data;
387 	struct subchannel *sch;
388 
389 	res_data = (struct res_acc_data *)data;
390 	sch = get_subchannel_by_schid(schid);
391 	if (!sch)
392 		/* Check if a subchannel is newly available. */
393 		return s390_process_res_acc_new_sch(schid);
394 
395 	spin_lock_irq(&sch->lock);
396 
397 	chp_mask = s390_process_res_acc_sch(res_data, sch);
398 
399 	if (chp_mask == 0) {
400 		spin_unlock_irq(&sch->lock);
401 		return 0;
402 	}
403 	old_lpm = sch->lpm;
404 	sch->lpm = ((sch->schib.pmcw.pim &
405 		     sch->schib.pmcw.pam &
406 		     sch->schib.pmcw.pom)
407 		    | chp_mask) & sch->opm;
408 	if (!old_lpm && sch->lpm)
409 		device_trigger_reprobe(sch);
410 	else if (sch->driver && sch->driver->verify)
411 		sch->driver->verify(&sch->dev);
412 
413 	spin_unlock_irq(&sch->lock);
414 	put_device(&sch->dev);
415 	return (res_data->fla_mask == 0xffff) ? -ENODEV : 0;
416 }
417 
418 
419 static int
420 s390_process_res_acc (struct res_acc_data *res_data)
421 {
422 	int rc;
423 	char dbf_txt[15];
424 
425 	sprintf(dbf_txt, "accpr%x", res_data->chp->id);
426 	CIO_TRACE_EVENT( 2, dbf_txt);
427 	if (res_data->fla != 0) {
428 		sprintf(dbf_txt, "fla%x", res_data->fla);
429 		CIO_TRACE_EVENT( 2, dbf_txt);
430 	}
431 
432 	/*
433 	 * I/O resources may have become accessible.
434 	 * Scan through all subchannels that may be concerned and
435 	 * do a validation on those.
436 	 * The more information we have (info), the less scanning
437 	 * will we have to do.
438 	 */
439 	rc = for_each_subchannel(__s390_process_res_acc, res_data);
440 	if (css_slow_subchannels_exist())
441 		rc = -EAGAIN;
442 	else if (rc != -EAGAIN)
443 		rc = 0;
444 	return rc;
445 }
446 
447 static int
448 __get_chpid_from_lir(void *data)
449 {
450 	struct lir {
451 		u8  iq;
452 		u8  ic;
453 		u16 sci;
454 		/* incident-node descriptor */
455 		u32 indesc[28];
456 		/* attached-node descriptor */
457 		u32 andesc[28];
458 		/* incident-specific information */
459 		u32 isinfo[28];
460 	} *lir;
461 
462 	lir = (struct lir*) data;
463 	if (!(lir->iq&0x80))
464 		/* NULL link incident record */
465 		return -EINVAL;
466 	if (!(lir->indesc[0]&0xc0000000))
467 		/* node descriptor not valid */
468 		return -EINVAL;
469 	if (!(lir->indesc[0]&0x10000000))
470 		/* don't handle device-type nodes - FIXME */
471 		return -EINVAL;
472 	/* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
473 
474 	return (u16) (lir->indesc[0]&0x000000ff);
475 }
476 
477 int
478 chsc_process_crw(void)
479 {
480 	int chpid, ret;
481 	struct res_acc_data res_data;
482 	struct {
483 		struct chsc_header request;
484 		u32 reserved1;
485 		u32 reserved2;
486 		u32 reserved3;
487 		struct chsc_header response;
488 		u32 reserved4;
489 		u8  flags;
490 		u8  vf;		/* validity flags */
491 		u8  rs;		/* reporting source */
492 		u8  cc;		/* content code */
493 		u16 fla;	/* full link address */
494 		u16 rsid;	/* reporting source id */
495 		u32 reserved5;
496 		u32 reserved6;
497 		u32 ccdf[96];	/* content-code dependent field */
498 		/* ccdf has to be big enough for a link-incident record */
499 	} *sei_area;
500 
501 	if (!sei_page)
502 		return 0;
503 	/*
504 	 * build the chsc request block for store event information
505 	 * and do the call
506 	 * This function is only called by the machine check handler thread,
507 	 * so we don't need locking for the sei_page.
508 	 */
509 	sei_area = sei_page;
510 
511 	CIO_TRACE_EVENT( 2, "prcss");
512 	ret = 0;
513 	do {
514 		int ccode, status;
515 		struct device *dev;
516 		memset(sei_area, 0, sizeof(*sei_area));
517 		memset(&res_data, 0, sizeof(struct res_acc_data));
518 		sei_area->request.length = 0x0010;
519 		sei_area->request.code = 0x000e;
520 
521 		ccode = chsc(sei_area);
522 		if (ccode > 0)
523 			return 0;
524 
525 		switch (sei_area->response.code) {
526 			/* for debug purposes, check for problems */
527 		case 0x0001:
528 			CIO_CRW_EVENT(4, "chsc_process_crw: event information "
529 					"successfully stored\n");
530 			break; /* everything ok */
531 		case 0x0002:
532 			CIO_CRW_EVENT(2,
533 				      "chsc_process_crw: invalid command!\n");
534 			return 0;
535 		case 0x0003:
536 			CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
537 				      "request block!\n");
538 			return 0;
539 		case 0x0005:
540 			CIO_CRW_EVENT(2, "chsc_process_crw: no event "
541 				      "information stored\n");
542 			return 0;
543 		default:
544 			CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
545 				      sei_area->response.code);
546 			return 0;
547 		}
548 
549 		/* Check if we might have lost some information. */
550 		if (sei_area->flags & 0x40)
551 			CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
552 				       "has been lost due to overflow!\n");
553 
554 		if (sei_area->rs != 4) {
555 			CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
556 				      "(%04X) isn't a chpid!\n",
557 				      sei_area->rsid);
558 			continue;
559 		}
560 
561 		/* which kind of information was stored? */
562 		switch (sei_area->cc) {
563 		case 1: /* link incident*/
564 			CIO_CRW_EVENT(4, "chsc_process_crw: "
565 				      "channel subsystem reports link incident,"
566 				      " reporting source is chpid %x\n",
567 				      sei_area->rsid);
568 			chpid = __get_chpid_from_lir(sei_area->ccdf);
569 			if (chpid < 0)
570 				CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
571 					      __FUNCTION__);
572 			else
573 				s390_set_chpid_offline(chpid);
574 			break;
575 
576 		case 2: /* i/o resource accessibiliy */
577 			CIO_CRW_EVENT(4, "chsc_process_crw: "
578 				      "channel subsystem reports some I/O "
579 				      "devices may have become accessible\n");
580 			pr_debug("Data received after sei: \n");
581 			pr_debug("Validity flags: %x\n", sei_area->vf);
582 
583 			/* allocate a new channel path structure, if needed */
584 			status = get_chp_status(sei_area->rsid);
585 			if (status < 0)
586 				new_channel_path(sei_area->rsid);
587 			else if (!status)
588 				break;
589 			dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
590 			res_data.chp = to_channelpath(dev);
591 			pr_debug("chpid: %x", sei_area->rsid);
592 			if ((sei_area->vf & 0xc0) != 0) {
593 				res_data.fla = sei_area->fla;
594 				if ((sei_area->vf & 0xc0) == 0xc0) {
595 					pr_debug(" full link addr: %x",
596 						 sei_area->fla);
597 					res_data.fla_mask = 0xffff;
598 				} else {
599 					pr_debug(" link addr: %x",
600 						 sei_area->fla);
601 					res_data.fla_mask = 0xff00;
602 				}
603 			}
604 			ret = s390_process_res_acc(&res_data);
605 			pr_debug("\n\n");
606 			put_device(dev);
607 			break;
608 
609 		default: /* other stuff */
610 			CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
611 				      sei_area->cc);
612 			break;
613 		}
614 	} while (sei_area->flags & 0x80);
615 	return ret;
616 }
617 
618 static inline int
619 __chp_add_new_sch(struct subchannel_id schid)
620 {
621 	struct schib schib;
622 	int ret;
623 
624 	if (stsch(schid, &schib))
625 		/* We're through */
626 		return need_rescan ? -EAGAIN : -ENXIO;
627 
628 	/* Put it on the slow path. */
629 	ret = css_enqueue_subchannel_slow(schid);
630 	if (ret) {
631 		css_clear_subchannel_slow_list();
632 		need_rescan = 1;
633 		return -EAGAIN;
634 	}
635 	return 0;
636 }
637 
638 
639 static int
640 __chp_add(struct subchannel_id schid, void *data)
641 {
642 	int i;
643 	struct channel_path *chp;
644 	struct subchannel *sch;
645 
646 	chp = (struct channel_path *)data;
647 	sch = get_subchannel_by_schid(schid);
648 	if (!sch)
649 		/* Check if the subchannel is now available. */
650 		return __chp_add_new_sch(schid);
651 	spin_lock_irq(&sch->lock);
652 	for (i=0; i<8; i++)
653 		if (sch->schib.pmcw.chpid[i] == chp->id) {
654 			if (stsch(sch->schid, &sch->schib) != 0) {
655 				/* Endgame. */
656 				spin_unlock(&sch->lock);
657 				return -ENXIO;
658 			}
659 			break;
660 		}
661 	if (i==8) {
662 		spin_unlock(&sch->lock);
663 		return 0;
664 	}
665 	sch->lpm = ((sch->schib.pmcw.pim &
666 		     sch->schib.pmcw.pam &
667 		     sch->schib.pmcw.pom)
668 		    | 0x80 >> i) & sch->opm;
669 
670 	if (sch->driver && sch->driver->verify)
671 		sch->driver->verify(&sch->dev);
672 
673 	spin_unlock_irq(&sch->lock);
674 	put_device(&sch->dev);
675 	return 0;
676 }
677 
678 static int
679 chp_add(int chpid)
680 {
681 	int rc;
682 	char dbf_txt[15];
683 	struct device *dev;
684 
685 	if (!get_chp_status(chpid))
686 		return 0; /* no need to do the rest */
687 
688 	sprintf(dbf_txt, "cadd%x", chpid);
689 	CIO_TRACE_EVENT(2, dbf_txt);
690 
691 	dev = get_device(&css[0]->chps[chpid]->dev);
692 	rc = for_each_subchannel(__chp_add, to_channelpath(dev));
693 	if (css_slow_subchannels_exist())
694 		rc = -EAGAIN;
695 	if (rc != -EAGAIN)
696 		rc = 0;
697 	put_device(dev);
698 	return rc;
699 }
700 
701 /*
702  * Handling of crw machine checks with channel path source.
703  */
704 int
705 chp_process_crw(int chpid, int on)
706 {
707 	if (on == 0) {
708 		/* Path has gone. We use the link incident routine.*/
709 		s390_set_chpid_offline(chpid);
710 		return 0; /* De-register is async anyway. */
711 	}
712 	/*
713 	 * Path has come. Allocate a new channel path structure,
714 	 * if needed.
715 	 */
716 	if (get_chp_status(chpid) < 0)
717 		new_channel_path(chpid);
718 	/* Avoid the extra overhead in process_rec_acc. */
719 	return chp_add(chpid);
720 }
721 
722 static inline int
723 __check_for_io_and_kill(struct subchannel *sch, int index)
724 {
725 	int cc;
726 
727 	if (!device_is_online(sch))
728 		/* cio could be doing I/O. */
729 		return 0;
730 	cc = stsch(sch->schid, &sch->schib);
731 	if (cc)
732 		return 0;
733 	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
734 		device_set_waiting(sch);
735 		return 1;
736 	}
737 	return 0;
738 }
739 
740 static inline void
741 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
742 {
743 	int chp, old_lpm;
744 	unsigned long flags;
745 
746 	if (!sch->ssd_info.valid)
747 		return;
748 
749 	spin_lock_irqsave(&sch->lock, flags);
750 	old_lpm = sch->lpm;
751 	for (chp = 0; chp < 8; chp++) {
752 		if (sch->ssd_info.chpid[chp] != chpid)
753 			continue;
754 
755 		if (on) {
756 			sch->opm |= (0x80 >> chp);
757 			sch->lpm |= (0x80 >> chp);
758 			if (!old_lpm)
759 				device_trigger_reprobe(sch);
760 			else if (sch->driver && sch->driver->verify)
761 				sch->driver->verify(&sch->dev);
762 		} else {
763 			sch->opm &= ~(0x80 >> chp);
764 			sch->lpm &= ~(0x80 >> chp);
765 			/*
766 			 * Give running I/O a grace period in which it
767 			 * can successfully terminate, even using the
768 			 * just varied off path. Then kill it.
769 			 */
770 			if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
771 				if (css_enqueue_subchannel_slow(sch->schid)) {
772 					css_clear_subchannel_slow_list();
773 					need_rescan = 1;
774 				}
775 			} else if (sch->driver && sch->driver->verify)
776 				sch->driver->verify(&sch->dev);
777 		}
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_chars);
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 	return count;
946 }
947 
948 static struct bin_attribute chp_measurement_attr = {
949 	.attr = {
950 		.name = "measurement",
951 		.mode = S_IRUSR,
952 		.owner = THIS_MODULE,
953 	},
954 	.size = sizeof(struct cmg_entry),
955 	.read = chp_measurement_read,
956 };
957 
958 static void
959 chsc_remove_chp_cmg_attr(struct channel_path *chp)
960 {
961 	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
962 	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
963 }
964 
965 static int
966 chsc_add_chp_cmg_attr(struct channel_path *chp)
967 {
968 	int ret;
969 
970 	ret = sysfs_create_bin_file(&chp->dev.kobj,
971 				    &chp_measurement_chars_attr);
972 	if (ret)
973 		return ret;
974 	ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
975 	if (ret)
976 		sysfs_remove_bin_file(&chp->dev.kobj,
977 				      &chp_measurement_chars_attr);
978 	return ret;
979 }
980 
981 static void
982 chsc_remove_cmg_attr(struct channel_subsystem *css)
983 {
984 	int i;
985 
986 	for (i = 0; i <= __MAX_CHPID; i++) {
987 		if (!css->chps[i])
988 			continue;
989 		chsc_remove_chp_cmg_attr(css->chps[i]);
990 	}
991 }
992 
993 static int
994 chsc_add_cmg_attr(struct channel_subsystem *css)
995 {
996 	int i, ret;
997 
998 	ret = 0;
999 	for (i = 0; i <= __MAX_CHPID; i++) {
1000 		if (!css->chps[i])
1001 			continue;
1002 		ret = chsc_add_chp_cmg_attr(css->chps[i]);
1003 		if (ret)
1004 			goto cleanup;
1005 	}
1006 	return ret;
1007 cleanup:
1008 	for (--i; i >= 0; i--) {
1009 		if (!css->chps[i])
1010 			continue;
1011 		chsc_remove_chp_cmg_attr(css->chps[i]);
1012 	}
1013 	return ret;
1014 }
1015 
1016 
1017 static int
1018 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1019 {
1020 	struct {
1021 		struct chsc_header request;
1022 		u32 operation_code : 2;
1023 		u32 : 30;
1024 		u32 key : 4;
1025 		u32 : 28;
1026 		u32 zeroes1;
1027 		u32 cub_addr1;
1028 		u32 zeroes2;
1029 		u32 cub_addr2;
1030 		u32 reserved[13];
1031 		struct chsc_header response;
1032 		u32 status : 8;
1033 		u32 : 4;
1034 		u32 fmt : 4;
1035 		u32 : 16;
1036 	} *secm_area;
1037 	int ret, ccode;
1038 
1039 	secm_area = page;
1040 	secm_area->request.length = 0x0050;
1041 	secm_area->request.code = 0x0016;
1042 
1043 	secm_area->key = PAGE_DEFAULT_KEY;
1044 	secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1045 	secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1046 
1047 	secm_area->operation_code = enable ? 0 : 1;
1048 
1049 	ccode = chsc(secm_area);
1050 	if (ccode > 0)
1051 		return (ccode == 3) ? -ENODEV : -EBUSY;
1052 
1053 	switch (secm_area->response.code) {
1054 	case 0x0001: /* Success. */
1055 		ret = 0;
1056 		break;
1057 	case 0x0003: /* Invalid block. */
1058 	case 0x0007: /* Invalid format. */
1059 	case 0x0008: /* Other invalid block. */
1060 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1061 		ret = -EINVAL;
1062 		break;
1063 	case 0x0004: /* Command not provided in model. */
1064 		CIO_CRW_EVENT(2, "Model does not provide secm\n");
1065 		ret = -EOPNOTSUPP;
1066 		break;
1067 	case 0x0102: /* cub adresses incorrect */
1068 		CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1069 		ret = -EINVAL;
1070 		break;
1071 	case 0x0103: /* key error */
1072 		CIO_CRW_EVENT(2, "Access key error in secm\n");
1073 		ret = -EINVAL;
1074 		break;
1075 	case 0x0105: /* error while starting */
1076 		CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1077 		ret = -EIO;
1078 		break;
1079 	default:
1080 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1081 			      secm_area->response.code);
1082 		ret = -EIO;
1083 	}
1084 	return ret;
1085 }
1086 
1087 int
1088 chsc_secm(struct channel_subsystem *css, int enable)
1089 {
1090 	void  *secm_area;
1091 	int ret;
1092 
1093 	secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1094 	if (!secm_area)
1095 		return -ENOMEM;
1096 
1097 	mutex_lock(&css->mutex);
1098 	if (enable && !css->cm_enabled) {
1099 		css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1100 		css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1101 		if (!css->cub_addr1 || !css->cub_addr2) {
1102 			free_page((unsigned long)css->cub_addr1);
1103 			free_page((unsigned long)css->cub_addr2);
1104 			free_page((unsigned long)secm_area);
1105 			mutex_unlock(&css->mutex);
1106 			return -ENOMEM;
1107 		}
1108 	}
1109 	ret = __chsc_do_secm(css, enable, secm_area);
1110 	if (!ret) {
1111 		css->cm_enabled = enable;
1112 		if (css->cm_enabled) {
1113 			ret = chsc_add_cmg_attr(css);
1114 			if (ret) {
1115 				memset(secm_area, 0, PAGE_SIZE);
1116 				__chsc_do_secm(css, 0, secm_area);
1117 				css->cm_enabled = 0;
1118 			}
1119 		} else
1120 			chsc_remove_cmg_attr(css);
1121 	}
1122 	if (enable && !css->cm_enabled) {
1123 		free_page((unsigned long)css->cub_addr1);
1124 		free_page((unsigned long)css->cub_addr2);
1125 	}
1126 	mutex_unlock(&css->mutex);
1127 	free_page((unsigned long)secm_area);
1128 	return ret;
1129 }
1130 
1131 /*
1132  * Files for the channel path entries.
1133  */
1134 static ssize_t
1135 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1136 {
1137 	struct channel_path *chp = container_of(dev, struct channel_path, dev);
1138 
1139 	if (!chp)
1140 		return 0;
1141 	return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1142 		sprintf(buf, "offline\n"));
1143 }
1144 
1145 static ssize_t
1146 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1147 {
1148 	struct channel_path *cp = container_of(dev, struct channel_path, dev);
1149 	char cmd[10];
1150 	int num_args;
1151 	int error;
1152 
1153 	num_args = sscanf(buf, "%5s", cmd);
1154 	if (!num_args)
1155 		return count;
1156 
1157 	if (!strnicmp(cmd, "on", 2))
1158 		error = s390_vary_chpid(cp->id, 1);
1159 	else if (!strnicmp(cmd, "off", 3))
1160 		error = s390_vary_chpid(cp->id, 0);
1161 	else
1162 		error = -EINVAL;
1163 
1164 	return error < 0 ? error : count;
1165 
1166 }
1167 
1168 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1169 
1170 static ssize_t
1171 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1172 {
1173 	struct channel_path *chp = container_of(dev, struct channel_path, dev);
1174 
1175 	if (!chp)
1176 		return 0;
1177 	return sprintf(buf, "%x\n", chp->desc.desc);
1178 }
1179 
1180 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1181 
1182 static ssize_t
1183 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1184 {
1185 	struct channel_path *chp = to_channelpath(dev);
1186 
1187 	if (!chp)
1188 		return 0;
1189 	if (chp->cmg == -1) /* channel measurements not available */
1190 		return sprintf(buf, "unknown\n");
1191 	return sprintf(buf, "%x\n", chp->cmg);
1192 }
1193 
1194 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1195 
1196 static ssize_t
1197 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1198 {
1199 	struct channel_path *chp = to_channelpath(dev);
1200 
1201 	if (!chp)
1202 		return 0;
1203 	if (chp->shared == -1) /* channel measurements not available */
1204 		return sprintf(buf, "unknown\n");
1205 	return sprintf(buf, "%x\n", chp->shared);
1206 }
1207 
1208 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1209 
1210 static struct attribute * chp_attrs[] = {
1211 	&dev_attr_status.attr,
1212 	&dev_attr_type.attr,
1213 	&dev_attr_cmg.attr,
1214 	&dev_attr_shared.attr,
1215 	NULL,
1216 };
1217 
1218 static struct attribute_group chp_attr_group = {
1219 	.attrs = chp_attrs,
1220 };
1221 
1222 static void
1223 chp_release(struct device *dev)
1224 {
1225 	struct channel_path *cp;
1226 
1227 	cp = container_of(dev, struct channel_path, dev);
1228 	kfree(cp);
1229 }
1230 
1231 static int
1232 chsc_determine_channel_path_description(int chpid,
1233 					struct channel_path_desc *desc)
1234 {
1235 	int ccode, ret;
1236 
1237 	struct {
1238 		struct chsc_header request;
1239 		u32 : 24;
1240 		u32 first_chpid : 8;
1241 		u32 : 24;
1242 		u32 last_chpid : 8;
1243 		u32 zeroes1;
1244 		struct chsc_header response;
1245 		u32 zeroes2;
1246 		struct channel_path_desc desc;
1247 	} *scpd_area;
1248 
1249 	scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1250 	if (!scpd_area)
1251 		return -ENOMEM;
1252 
1253 	scpd_area->request.length = 0x0010;
1254 	scpd_area->request.code = 0x0002;
1255 
1256 	scpd_area->first_chpid = chpid;
1257 	scpd_area->last_chpid = chpid;
1258 
1259 	ccode = chsc(scpd_area);
1260 	if (ccode > 0) {
1261 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
1262 		goto out;
1263 	}
1264 
1265 	switch (scpd_area->response.code) {
1266 	case 0x0001: /* Success. */
1267 		memcpy(desc, &scpd_area->desc,
1268 		       sizeof(struct channel_path_desc));
1269 		ret = 0;
1270 		break;
1271 	case 0x0003: /* Invalid block. */
1272 	case 0x0007: /* Invalid format. */
1273 	case 0x0008: /* Other invalid block. */
1274 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1275 		ret = -EINVAL;
1276 		break;
1277 	case 0x0004: /* Command not provided in model. */
1278 		CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1279 		ret = -EOPNOTSUPP;
1280 		break;
1281 	default:
1282 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1283 			      scpd_area->response.code);
1284 		ret = -EIO;
1285 	}
1286 out:
1287 	free_page((unsigned long)scpd_area);
1288 	return ret;
1289 }
1290 
1291 static void
1292 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1293 			  struct cmg_chars *chars)
1294 {
1295 	switch (chp->cmg) {
1296 	case 2:
1297 	case 3:
1298 		chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1299 					 GFP_KERNEL);
1300 		if (chp->cmg_chars) {
1301 			int i, mask;
1302 			struct cmg_chars *cmg_chars;
1303 
1304 			cmg_chars = chp->cmg_chars;
1305 			for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1306 				mask = 0x80 >> (i + 3);
1307 				if (cmcv & mask)
1308 					cmg_chars->values[i] = chars->values[i];
1309 				else
1310 					cmg_chars->values[i] = 0;
1311 			}
1312 		}
1313 		break;
1314 	default:
1315 		/* No cmg-dependent data. */
1316 		break;
1317 	}
1318 }
1319 
1320 static int
1321 chsc_get_channel_measurement_chars(struct channel_path *chp)
1322 {
1323 	int ccode, ret;
1324 
1325 	struct {
1326 		struct chsc_header request;
1327 		u32 : 24;
1328 		u32 first_chpid : 8;
1329 		u32 : 24;
1330 		u32 last_chpid : 8;
1331 		u32 zeroes1;
1332 		struct chsc_header response;
1333 		u32 zeroes2;
1334 		u32 not_valid : 1;
1335 		u32 shared : 1;
1336 		u32 : 22;
1337 		u32 chpid : 8;
1338 		u32 cmcv : 5;
1339 		u32 : 11;
1340 		u32 cmgq : 8;
1341 		u32 cmg : 8;
1342 		u32 zeroes3;
1343 		u32 data[NR_MEASUREMENT_CHARS];
1344 	} *scmc_area;
1345 
1346 	scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1347 	if (!scmc_area)
1348 		return -ENOMEM;
1349 
1350 	scmc_area->request.length = 0x0010;
1351 	scmc_area->request.code = 0x0022;
1352 
1353 	scmc_area->first_chpid = chp->id;
1354 	scmc_area->last_chpid = chp->id;
1355 
1356 	ccode = chsc(scmc_area);
1357 	if (ccode > 0) {
1358 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
1359 		goto out;
1360 	}
1361 
1362 	switch (scmc_area->response.code) {
1363 	case 0x0001: /* Success. */
1364 		if (!scmc_area->not_valid) {
1365 			chp->cmg = scmc_area->cmg;
1366 			chp->shared = scmc_area->shared;
1367 			chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1368 						  (struct cmg_chars *)
1369 						  &scmc_area->data);
1370 		} else {
1371 			chp->cmg = -1;
1372 			chp->shared = -1;
1373 		}
1374 		ret = 0;
1375 		break;
1376 	case 0x0003: /* Invalid block. */
1377 	case 0x0007: /* Invalid format. */
1378 	case 0x0008: /* Invalid bit combination. */
1379 		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1380 		ret = -EINVAL;
1381 		break;
1382 	case 0x0004: /* Command not provided. */
1383 		CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1384 		ret = -EOPNOTSUPP;
1385 		break;
1386 	default:
1387 		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1388 			      scmc_area->response.code);
1389 		ret = -EIO;
1390 	}
1391 out:
1392 	free_page((unsigned long)scmc_area);
1393 	return ret;
1394 }
1395 
1396 /*
1397  * Entries for chpids on the system bus.
1398  * This replaces /proc/chpids.
1399  */
1400 static int
1401 new_channel_path(int chpid)
1402 {
1403 	struct channel_path *chp;
1404 	int ret;
1405 
1406 	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1407 	if (!chp)
1408 		return -ENOMEM;
1409 
1410 	/* fill in status, etc. */
1411 	chp->id = chpid;
1412 	chp->state = 1;
1413 	chp->dev = (struct device) {
1414 		.parent  = &css[0]->device,
1415 		.release = chp_release,
1416 	};
1417 	snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1418 
1419 	/* Obtain channel path description and fill it in. */
1420 	ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1421 	if (ret)
1422 		goto out_free;
1423 	/* Get channel-measurement characteristics. */
1424 	if (css_characteristics_avail && css_chsc_characteristics.scmc
1425 	    && css_chsc_characteristics.secm) {
1426 		ret = chsc_get_channel_measurement_chars(chp);
1427 		if (ret)
1428 			goto out_free;
1429 	} else {
1430 		static int msg_done;
1431 
1432 		if (!msg_done) {
1433 			printk(KERN_WARNING "cio: Channel measurements not "
1434 			       "available, continuing.\n");
1435 			msg_done = 1;
1436 		}
1437 		chp->cmg = -1;
1438 	}
1439 
1440 	/* make it known to the system */
1441 	ret = device_register(&chp->dev);
1442 	if (ret) {
1443 		printk(KERN_WARNING "%s: could not register %02x\n",
1444 		       __func__, chpid);
1445 		goto out_free;
1446 	}
1447 	ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1448 	if (ret) {
1449 		device_unregister(&chp->dev);
1450 		goto out_free;
1451 	}
1452 	mutex_lock(&css[0]->mutex);
1453 	if (css[0]->cm_enabled) {
1454 		ret = chsc_add_chp_cmg_attr(chp);
1455 		if (ret) {
1456 			sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1457 			device_unregister(&chp->dev);
1458 			mutex_unlock(&css[0]->mutex);
1459 			goto out_free;
1460 		}
1461 	}
1462 	css[0]->chps[chpid] = chp;
1463 	mutex_unlock(&css[0]->mutex);
1464 	return ret;
1465 out_free:
1466 	kfree(chp);
1467 	return ret;
1468 }
1469 
1470 void *
1471 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1472 {
1473 	struct channel_path *chp;
1474 	struct channel_path_desc *desc;
1475 
1476 	chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1477 	if (!chp)
1478 		return NULL;
1479 	desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1480 	if (!desc)
1481 		return NULL;
1482 	memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1483 	return desc;
1484 }
1485 
1486 
1487 static int __init
1488 chsc_alloc_sei_area(void)
1489 {
1490 	sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1491 	if (!sei_page)
1492 		printk(KERN_WARNING"Can't allocate page for processing of " \
1493 		       "chsc machine checks!\n");
1494 	return (sei_page ? 0 : -ENOMEM);
1495 }
1496 
1497 int __init
1498 chsc_enable_facility(int operation_code)
1499 {
1500 	int ret;
1501 	struct {
1502 		struct chsc_header request;
1503 		u8 reserved1:4;
1504 		u8 format:4;
1505 		u8 reserved2;
1506 		u16 operation_code;
1507 		u32 reserved3;
1508 		u32 reserved4;
1509 		u32 operation_data_area[252];
1510 		struct chsc_header response;
1511 		u32 reserved5:4;
1512 		u32 format2:4;
1513 		u32 reserved6:24;
1514 	} *sda_area;
1515 
1516 	sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1517 	if (!sda_area)
1518 		return -ENOMEM;
1519 	sda_area->request.length = 0x0400;
1520 	sda_area->request.code = 0x0031;
1521 	sda_area->operation_code = operation_code;
1522 
1523 	ret = chsc(sda_area);
1524 	if (ret > 0) {
1525 		ret = (ret == 3) ? -ENODEV : -EBUSY;
1526 		goto out;
1527 	}
1528 	switch (sda_area->response.code) {
1529 	case 0x0001: /* everything ok */
1530 		ret = 0;
1531 		break;
1532 	case 0x0003: /* invalid request block */
1533 	case 0x0007:
1534 		ret = -EINVAL;
1535 		break;
1536 	case 0x0004: /* command not provided */
1537 	case 0x0101: /* facility not provided */
1538 		ret = -EOPNOTSUPP;
1539 		break;
1540 	default: /* something went wrong */
1541 		ret = -EIO;
1542 	}
1543  out:
1544 	free_page((unsigned long)sda_area);
1545 	return ret;
1546 }
1547 
1548 subsys_initcall(chsc_alloc_sei_area);
1549 
1550 struct css_general_char css_general_characteristics;
1551 struct css_chsc_char css_chsc_characteristics;
1552 
1553 int __init
1554 chsc_determine_css_characteristics(void)
1555 {
1556 	int result;
1557 	struct {
1558 		struct chsc_header request;
1559 		u32 reserved1;
1560 		u32 reserved2;
1561 		u32 reserved3;
1562 		struct chsc_header response;
1563 		u32 reserved4;
1564 		u32 general_char[510];
1565 		u32 chsc_char[518];
1566 	} *scsc_area;
1567 
1568 	scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1569 	if (!scsc_area) {
1570 	        printk(KERN_WARNING"cio: Was not able to determine available" \
1571 		       "CHSCs due to no memory.\n");
1572 		return -ENOMEM;
1573 	}
1574 
1575 	scsc_area->request.length = 0x0010;
1576 	scsc_area->request.code = 0x0010;
1577 
1578 	result = chsc(scsc_area);
1579 	if (result) {
1580 		printk(KERN_WARNING"cio: Was not able to determine " \
1581 		       "available CHSCs, cc=%i.\n", result);
1582 		result = -EIO;
1583 		goto exit;
1584 	}
1585 
1586 	if (scsc_area->response.code != 1) {
1587 		printk(KERN_WARNING"cio: Was not able to determine " \
1588 		       "available CHSCs.\n");
1589 		result = -EIO;
1590 		goto exit;
1591 	}
1592 	memcpy(&css_general_characteristics, scsc_area->general_char,
1593 	       sizeof(css_general_characteristics));
1594 	memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1595 	       sizeof(css_chsc_characteristics));
1596 exit:
1597 	free_page ((unsigned long) scsc_area);
1598 	return result;
1599 }
1600 
1601 EXPORT_SYMBOL_GPL(css_general_characteristics);
1602 EXPORT_SYMBOL_GPL(css_chsc_characteristics);
1603