xref: /openbmc/linux/drivers/s390/cio/chsc.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  *  drivers/s390/cio/chsc.c
3  *   S/390 common I/O routines -- channel subsystem call
4  *
5  *    Copyright IBM Corp. 1999,2008
6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
7  *		 Cornelia Huck (cornelia.huck@de.ibm.com)
8  *		 Arnd Bergmann (arndb@de.ibm.com)
9  */
10 
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/init.h>
17 #include <linux/device.h>
18 
19 #include <asm/cio.h>
20 #include <asm/chpid.h>
21 #include <asm/chsc.h>
22 #include <asm/crw.h>
23 
24 #include "css.h"
25 #include "cio.h"
26 #include "cio_debug.h"
27 #include "ioasm.h"
28 #include "chp.h"
29 #include "chsc.h"
30 
31 static void *sei_page;
32 
33 /**
34  * chsc_error_from_response() - convert a chsc response to an error
35  * @response: chsc response code
36  *
37  * Returns an appropriate Linux error code for @response.
38  */
39 int chsc_error_from_response(int response)
40 {
41 	switch (response) {
42 	case 0x0001:
43 		return 0;
44 	case 0x0002:
45 	case 0x0003:
46 	case 0x0006:
47 	case 0x0007:
48 	case 0x0008:
49 	case 0x000a:
50 		return -EINVAL;
51 	case 0x0004:
52 		return -EOPNOTSUPP;
53 	default:
54 		return -EIO;
55 	}
56 }
57 EXPORT_SYMBOL_GPL(chsc_error_from_response);
58 
59 struct chsc_ssd_area {
60 	struct chsc_header request;
61 	u16 :10;
62 	u16 ssid:2;
63 	u16 :4;
64 	u16 f_sch;	  /* first subchannel */
65 	u16 :16;
66 	u16 l_sch;	  /* last subchannel */
67 	u32 :32;
68 	struct chsc_header response;
69 	u32 :32;
70 	u8 sch_valid : 1;
71 	u8 dev_valid : 1;
72 	u8 st	     : 3; /* subchannel type */
73 	u8 zeroes    : 3;
74 	u8  unit_addr;	  /* unit address */
75 	u16 devno;	  /* device number */
76 	u8 path_mask;
77 	u8 fla_valid_mask;
78 	u16 sch;	  /* subchannel */
79 	u8 chpid[8];	  /* chpids 0-7 */
80 	u16 fla[8];	  /* full link addresses 0-7 */
81 } __attribute__ ((packed));
82 
83 int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
84 {
85 	unsigned long page;
86 	struct chsc_ssd_area *ssd_area;
87 	int ccode;
88 	int ret;
89 	int i;
90 	int mask;
91 
92 	page = get_zeroed_page(GFP_KERNEL | GFP_DMA);
93 	if (!page)
94 		return -ENOMEM;
95 	ssd_area = (struct chsc_ssd_area *) page;
96 	ssd_area->request.length = 0x0010;
97 	ssd_area->request.code = 0x0004;
98 	ssd_area->ssid = schid.ssid;
99 	ssd_area->f_sch = schid.sch_no;
100 	ssd_area->l_sch = schid.sch_no;
101 
102 	ccode = chsc(ssd_area);
103 	/* Check response. */
104 	if (ccode > 0) {
105 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
106 		goto out_free;
107 	}
108 	ret = chsc_error_from_response(ssd_area->response.code);
109 	if (ret != 0) {
110 		CIO_MSG_EVENT(2, "chsc: ssd failed for 0.%x.%04x (rc=%04x)\n",
111 			      schid.ssid, schid.sch_no,
112 			      ssd_area->response.code);
113 		goto out_free;
114 	}
115 	if (!ssd_area->sch_valid) {
116 		ret = -ENODEV;
117 		goto out_free;
118 	}
119 	/* Copy data */
120 	ret = 0;
121 	memset(ssd, 0, sizeof(struct chsc_ssd_info));
122 	if ((ssd_area->st != SUBCHANNEL_TYPE_IO) &&
123 	    (ssd_area->st != SUBCHANNEL_TYPE_MSG))
124 		goto out_free;
125 	ssd->path_mask = ssd_area->path_mask;
126 	ssd->fla_valid_mask = ssd_area->fla_valid_mask;
127 	for (i = 0; i < 8; i++) {
128 		mask = 0x80 >> i;
129 		if (ssd_area->path_mask & mask) {
130 			chp_id_init(&ssd->chpid[i]);
131 			ssd->chpid[i].id = ssd_area->chpid[i];
132 		}
133 		if (ssd_area->fla_valid_mask & mask)
134 			ssd->fla[i] = ssd_area->fla[i];
135 	}
136 out_free:
137 	free_page(page);
138 	return ret;
139 }
140 
141 static int s390_subchannel_remove_chpid(struct subchannel *sch, void *data)
142 {
143 	spin_lock_irq(sch->lock);
144 	if (sch->driver && sch->driver->chp_event)
145 		if (sch->driver->chp_event(sch, data, CHP_OFFLINE) != 0)
146 			goto out_unreg;
147 	spin_unlock_irq(sch->lock);
148 	return 0;
149 
150 out_unreg:
151 	sch->lpm = 0;
152 	spin_unlock_irq(sch->lock);
153 	css_schedule_eval(sch->schid);
154 	return 0;
155 }
156 
157 void chsc_chp_offline(struct chp_id chpid)
158 {
159 	char dbf_txt[15];
160 	struct chp_link link;
161 
162 	sprintf(dbf_txt, "chpr%x.%02x", chpid.cssid, chpid.id);
163 	CIO_TRACE_EVENT(2, dbf_txt);
164 
165 	if (chp_get_status(chpid) <= 0)
166 		return;
167 	memset(&link, 0, sizeof(struct chp_link));
168 	link.chpid = chpid;
169 	/* Wait until previous actions have settled. */
170 	css_wait_for_slow_path();
171 	for_each_subchannel_staged(s390_subchannel_remove_chpid, NULL, &link);
172 }
173 
174 static int s390_process_res_acc_new_sch(struct subchannel_id schid, void *data)
175 {
176 	struct schib schib;
177 	/*
178 	 * We don't know the device yet, but since a path
179 	 * may be available now to the device we'll have
180 	 * to do recognition again.
181 	 * Since we don't have any idea about which chpid
182 	 * that beast may be on we'll have to do a stsch
183 	 * on all devices, grr...
184 	 */
185 	if (stsch_err(schid, &schib))
186 		/* We're through */
187 		return -ENXIO;
188 
189 	/* Put it on the slow path. */
190 	css_schedule_eval(schid);
191 	return 0;
192 }
193 
194 static int __s390_process_res_acc(struct subchannel *sch, void *data)
195 {
196 	spin_lock_irq(sch->lock);
197 	if (sch->driver && sch->driver->chp_event)
198 		sch->driver->chp_event(sch, data, CHP_ONLINE);
199 	spin_unlock_irq(sch->lock);
200 
201 	return 0;
202 }
203 
204 static void s390_process_res_acc(struct chp_link *link)
205 {
206 	char dbf_txt[15];
207 
208 	sprintf(dbf_txt, "accpr%x.%02x", link->chpid.cssid,
209 		link->chpid.id);
210 	CIO_TRACE_EVENT( 2, dbf_txt);
211 	if (link->fla != 0) {
212 		sprintf(dbf_txt, "fla%x", link->fla);
213 		CIO_TRACE_EVENT( 2, dbf_txt);
214 	}
215 	/* Wait until previous actions have settled. */
216 	css_wait_for_slow_path();
217 	/*
218 	 * I/O resources may have become accessible.
219 	 * Scan through all subchannels that may be concerned and
220 	 * do a validation on those.
221 	 * The more information we have (info), the less scanning
222 	 * will we have to do.
223 	 */
224 	for_each_subchannel_staged(__s390_process_res_acc,
225 				   s390_process_res_acc_new_sch, link);
226 }
227 
228 static int
229 __get_chpid_from_lir(void *data)
230 {
231 	struct lir {
232 		u8  iq;
233 		u8  ic;
234 		u16 sci;
235 		/* incident-node descriptor */
236 		u32 indesc[28];
237 		/* attached-node descriptor */
238 		u32 andesc[28];
239 		/* incident-specific information */
240 		u32 isinfo[28];
241 	} __attribute__ ((packed)) *lir;
242 
243 	lir = data;
244 	if (!(lir->iq&0x80))
245 		/* NULL link incident record */
246 		return -EINVAL;
247 	if (!(lir->indesc[0]&0xc0000000))
248 		/* node descriptor not valid */
249 		return -EINVAL;
250 	if (!(lir->indesc[0]&0x10000000))
251 		/* don't handle device-type nodes - FIXME */
252 		return -EINVAL;
253 	/* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
254 
255 	return (u16) (lir->indesc[0]&0x000000ff);
256 }
257 
258 struct chsc_sei_area {
259 	struct chsc_header request;
260 	u32 reserved1;
261 	u32 reserved2;
262 	u32 reserved3;
263 	struct chsc_header response;
264 	u32 reserved4;
265 	u8  flags;
266 	u8  vf;		/* validity flags */
267 	u8  rs;		/* reporting source */
268 	u8  cc;		/* content code */
269 	u16 fla;	/* full link address */
270 	u16 rsid;	/* reporting source id */
271 	u32 reserved5;
272 	u32 reserved6;
273 	u8 ccdf[4096 - 16 - 24];	/* content-code dependent field */
274 	/* ccdf has to be big enough for a link-incident record */
275 } __attribute__ ((packed));
276 
277 static void chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
278 {
279 	struct chp_id chpid;
280 	int id;
281 
282 	CIO_CRW_EVENT(4, "chsc: link incident (rs=%02x, rs_id=%04x)\n",
283 		      sei_area->rs, sei_area->rsid);
284 	if (sei_area->rs != 4)
285 		return;
286 	id = __get_chpid_from_lir(sei_area->ccdf);
287 	if (id < 0)
288 		CIO_CRW_EVENT(4, "chsc: link incident - invalid LIR\n");
289 	else {
290 		chp_id_init(&chpid);
291 		chpid.id = id;
292 		chsc_chp_offline(chpid);
293 	}
294 }
295 
296 static void chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
297 {
298 	struct chp_link link;
299 	struct chp_id chpid;
300 	int status;
301 
302 	CIO_CRW_EVENT(4, "chsc: resource accessibility event (rs=%02x, "
303 		      "rs_id=%04x)\n", sei_area->rs, sei_area->rsid);
304 	if (sei_area->rs != 4)
305 		return;
306 	chp_id_init(&chpid);
307 	chpid.id = sei_area->rsid;
308 	/* allocate a new channel path structure, if needed */
309 	status = chp_get_status(chpid);
310 	if (status < 0)
311 		chp_new(chpid);
312 	else if (!status)
313 		return;
314 	memset(&link, 0, sizeof(struct chp_link));
315 	link.chpid = chpid;
316 	if ((sei_area->vf & 0xc0) != 0) {
317 		link.fla = sei_area->fla;
318 		if ((sei_area->vf & 0xc0) == 0xc0)
319 			/* full link address */
320 			link.fla_mask = 0xffff;
321 		else
322 			/* link address */
323 			link.fla_mask = 0xff00;
324 	}
325 	s390_process_res_acc(&link);
326 }
327 
328 struct chp_config_data {
329 	u8 map[32];
330 	u8 op;
331 	u8 pc;
332 };
333 
334 static void chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
335 {
336 	struct chp_config_data *data;
337 	struct chp_id chpid;
338 	int num;
339 	char *events[3] = {"configure", "deconfigure", "cancel deconfigure"};
340 
341 	CIO_CRW_EVENT(4, "chsc: channel-path-configuration notification\n");
342 	if (sei_area->rs != 0)
343 		return;
344 	data = (struct chp_config_data *) &(sei_area->ccdf);
345 	chp_id_init(&chpid);
346 	for (num = 0; num <= __MAX_CHPID; num++) {
347 		if (!chp_test_bit(data->map, num))
348 			continue;
349 		chpid.id = num;
350 		pr_notice("Processing %s for channel path %x.%02x\n",
351 			  events[data->op], chpid.cssid, chpid.id);
352 		switch (data->op) {
353 		case 0:
354 			chp_cfg_schedule(chpid, 1);
355 			break;
356 		case 1:
357 			chp_cfg_schedule(chpid, 0);
358 			break;
359 		case 2:
360 			chp_cfg_cancel_deconfigure(chpid);
361 			break;
362 		}
363 	}
364 }
365 
366 static void chsc_process_sei(struct chsc_sei_area *sei_area)
367 {
368 	/* Check if we might have lost some information. */
369 	if (sei_area->flags & 0x40) {
370 		CIO_CRW_EVENT(2, "chsc: event overflow\n");
371 		css_schedule_eval_all();
372 	}
373 	/* which kind of information was stored? */
374 	switch (sei_area->cc) {
375 	case 1: /* link incident*/
376 		chsc_process_sei_link_incident(sei_area);
377 		break;
378 	case 2: /* i/o resource accessibiliy */
379 		chsc_process_sei_res_acc(sei_area);
380 		break;
381 	case 8: /* channel-path-configuration notification */
382 		chsc_process_sei_chp_config(sei_area);
383 		break;
384 	default: /* other stuff */
385 		CIO_CRW_EVENT(4, "chsc: unhandled sei content code %d\n",
386 			      sei_area->cc);
387 		break;
388 	}
389 }
390 
391 static void chsc_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
392 {
393 	struct chsc_sei_area *sei_area;
394 
395 	if (overflow) {
396 		css_schedule_eval_all();
397 		return;
398 	}
399 	CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
400 		      "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
401 		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
402 		      crw0->erc, crw0->rsid);
403 	if (!sei_page)
404 		return;
405 	/* Access to sei_page is serialized through machine check handler
406 	 * thread, so no need for locking. */
407 	sei_area = sei_page;
408 
409 	CIO_TRACE_EVENT(2, "prcss");
410 	do {
411 		memset(sei_area, 0, sizeof(*sei_area));
412 		sei_area->request.length = 0x0010;
413 		sei_area->request.code = 0x000e;
414 		if (chsc(sei_area))
415 			break;
416 
417 		if (sei_area->response.code == 0x0001) {
418 			CIO_CRW_EVENT(4, "chsc: sei successful\n");
419 			chsc_process_sei(sei_area);
420 		} else {
421 			CIO_CRW_EVENT(2, "chsc: sei failed (rc=%04x)\n",
422 				      sei_area->response.code);
423 			break;
424 		}
425 	} while (sei_area->flags & 0x80);
426 }
427 
428 void chsc_chp_online(struct chp_id chpid)
429 {
430 	char dbf_txt[15];
431 	struct chp_link link;
432 
433 	sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);
434 	CIO_TRACE_EVENT(2, dbf_txt);
435 
436 	if (chp_get_status(chpid) != 0) {
437 		memset(&link, 0, sizeof(struct chp_link));
438 		link.chpid = chpid;
439 		/* Wait until previous actions have settled. */
440 		css_wait_for_slow_path();
441 		for_each_subchannel_staged(__s390_process_res_acc, NULL,
442 					   &link);
443 	}
444 }
445 
446 static void __s390_subchannel_vary_chpid(struct subchannel *sch,
447 					 struct chp_id chpid, int on)
448 {
449 	unsigned long flags;
450 	struct chp_link link;
451 
452 	memset(&link, 0, sizeof(struct chp_link));
453 	link.chpid = chpid;
454 	spin_lock_irqsave(sch->lock, flags);
455 	if (sch->driver && sch->driver->chp_event)
456 		sch->driver->chp_event(sch, &link,
457 				       on ? CHP_VARY_ON : CHP_VARY_OFF);
458 	spin_unlock_irqrestore(sch->lock, flags);
459 }
460 
461 static int s390_subchannel_vary_chpid_off(struct subchannel *sch, void *data)
462 {
463 	struct chp_id *chpid = data;
464 
465 	__s390_subchannel_vary_chpid(sch, *chpid, 0);
466 	return 0;
467 }
468 
469 static int s390_subchannel_vary_chpid_on(struct subchannel *sch, void *data)
470 {
471 	struct chp_id *chpid = data;
472 
473 	__s390_subchannel_vary_chpid(sch, *chpid, 1);
474 	return 0;
475 }
476 
477 static int
478 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
479 {
480 	struct schib schib;
481 
482 	if (stsch_err(schid, &schib))
483 		/* We're through */
484 		return -ENXIO;
485 	/* Put it on the slow path. */
486 	css_schedule_eval(schid);
487 	return 0;
488 }
489 
490 /**
491  * chsc_chp_vary - propagate channel-path vary operation to subchannels
492  * @chpid: channl-path ID
493  * @on: non-zero for vary online, zero for vary offline
494  */
495 int chsc_chp_vary(struct chp_id chpid, int on)
496 {
497 	struct chp_link link;
498 
499 	memset(&link, 0, sizeof(struct chp_link));
500 	link.chpid = chpid;
501 	/* Wait until previous actions have settled. */
502 	css_wait_for_slow_path();
503 	/*
504 	 * Redo PathVerification on the devices the chpid connects to
505 	 */
506 
507 	if (on)
508 		for_each_subchannel_staged(s390_subchannel_vary_chpid_on,
509 					   __s390_vary_chpid_on, &link);
510 	else
511 		for_each_subchannel_staged(s390_subchannel_vary_chpid_off,
512 					   NULL, &link);
513 
514 	return 0;
515 }
516 
517 static void
518 chsc_remove_cmg_attr(struct channel_subsystem *css)
519 {
520 	int i;
521 
522 	for (i = 0; i <= __MAX_CHPID; i++) {
523 		if (!css->chps[i])
524 			continue;
525 		chp_remove_cmg_attr(css->chps[i]);
526 	}
527 }
528 
529 static int
530 chsc_add_cmg_attr(struct channel_subsystem *css)
531 {
532 	int i, ret;
533 
534 	ret = 0;
535 	for (i = 0; i <= __MAX_CHPID; i++) {
536 		if (!css->chps[i])
537 			continue;
538 		ret = chp_add_cmg_attr(css->chps[i]);
539 		if (ret)
540 			goto cleanup;
541 	}
542 	return ret;
543 cleanup:
544 	for (--i; i >= 0; i--) {
545 		if (!css->chps[i])
546 			continue;
547 		chp_remove_cmg_attr(css->chps[i]);
548 	}
549 	return ret;
550 }
551 
552 static int
553 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
554 {
555 	struct {
556 		struct chsc_header request;
557 		u32 operation_code : 2;
558 		u32 : 30;
559 		u32 key : 4;
560 		u32 : 28;
561 		u32 zeroes1;
562 		u32 cub_addr1;
563 		u32 zeroes2;
564 		u32 cub_addr2;
565 		u32 reserved[13];
566 		struct chsc_header response;
567 		u32 status : 8;
568 		u32 : 4;
569 		u32 fmt : 4;
570 		u32 : 16;
571 	} __attribute__ ((packed)) *secm_area;
572 	int ret, ccode;
573 
574 	secm_area = page;
575 	secm_area->request.length = 0x0050;
576 	secm_area->request.code = 0x0016;
577 
578 	secm_area->key = PAGE_DEFAULT_KEY;
579 	secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
580 	secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
581 
582 	secm_area->operation_code = enable ? 0 : 1;
583 
584 	ccode = chsc(secm_area);
585 	if (ccode > 0)
586 		return (ccode == 3) ? -ENODEV : -EBUSY;
587 
588 	switch (secm_area->response.code) {
589 	case 0x0102:
590 	case 0x0103:
591 		ret = -EINVAL;
592 		break;
593 	default:
594 		ret = chsc_error_from_response(secm_area->response.code);
595 	}
596 	if (ret != 0)
597 		CIO_CRW_EVENT(2, "chsc: secm failed (rc=%04x)\n",
598 			      secm_area->response.code);
599 	return ret;
600 }
601 
602 int
603 chsc_secm(struct channel_subsystem *css, int enable)
604 {
605 	void  *secm_area;
606 	int ret;
607 
608 	secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
609 	if (!secm_area)
610 		return -ENOMEM;
611 
612 	if (enable && !css->cm_enabled) {
613 		css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
614 		css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
615 		if (!css->cub_addr1 || !css->cub_addr2) {
616 			free_page((unsigned long)css->cub_addr1);
617 			free_page((unsigned long)css->cub_addr2);
618 			free_page((unsigned long)secm_area);
619 			return -ENOMEM;
620 		}
621 	}
622 	ret = __chsc_do_secm(css, enable, secm_area);
623 	if (!ret) {
624 		css->cm_enabled = enable;
625 		if (css->cm_enabled) {
626 			ret = chsc_add_cmg_attr(css);
627 			if (ret) {
628 				memset(secm_area, 0, PAGE_SIZE);
629 				__chsc_do_secm(css, 0, secm_area);
630 				css->cm_enabled = 0;
631 			}
632 		} else
633 			chsc_remove_cmg_attr(css);
634 	}
635 	if (!css->cm_enabled) {
636 		free_page((unsigned long)css->cub_addr1);
637 		free_page((unsigned long)css->cub_addr2);
638 	}
639 	free_page((unsigned long)secm_area);
640 	return ret;
641 }
642 
643 int chsc_determine_channel_path_desc(struct chp_id chpid, int fmt, int rfmt,
644 				     int c, int m,
645 				     struct chsc_response_struct *resp)
646 {
647 	int ccode, ret;
648 
649 	struct {
650 		struct chsc_header request;
651 		u32 : 2;
652 		u32 m : 1;
653 		u32 c : 1;
654 		u32 fmt : 4;
655 		u32 cssid : 8;
656 		u32 : 4;
657 		u32 rfmt : 4;
658 		u32 first_chpid : 8;
659 		u32 : 24;
660 		u32 last_chpid : 8;
661 		u32 zeroes1;
662 		struct chsc_header response;
663 		u8 data[PAGE_SIZE - 20];
664 	} __attribute__ ((packed)) *scpd_area;
665 
666 	if ((rfmt == 1) && !css_general_characteristics.fcs)
667 		return -EINVAL;
668 	if ((rfmt == 2) && !css_general_characteristics.cib)
669 		return -EINVAL;
670 	scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
671 	if (!scpd_area)
672 		return -ENOMEM;
673 
674 	scpd_area->request.length = 0x0010;
675 	scpd_area->request.code = 0x0002;
676 
677 	scpd_area->cssid = chpid.cssid;
678 	scpd_area->first_chpid = chpid.id;
679 	scpd_area->last_chpid = chpid.id;
680 	scpd_area->m = m;
681 	scpd_area->c = c;
682 	scpd_area->fmt = fmt;
683 	scpd_area->rfmt = rfmt;
684 
685 	ccode = chsc(scpd_area);
686 	if (ccode > 0) {
687 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
688 		goto out;
689 	}
690 
691 	ret = chsc_error_from_response(scpd_area->response.code);
692 	if (ret == 0)
693 		/* Success. */
694 		memcpy(resp, &scpd_area->response, scpd_area->response.length);
695 	else
696 		CIO_CRW_EVENT(2, "chsc: scpd failed (rc=%04x)\n",
697 			      scpd_area->response.code);
698 out:
699 	free_page((unsigned long)scpd_area);
700 	return ret;
701 }
702 EXPORT_SYMBOL_GPL(chsc_determine_channel_path_desc);
703 
704 int chsc_determine_base_channel_path_desc(struct chp_id chpid,
705 					  struct channel_path_desc *desc)
706 {
707 	struct chsc_response_struct *chsc_resp;
708 	int ret;
709 
710 	chsc_resp = kzalloc(sizeof(*chsc_resp), GFP_KERNEL);
711 	if (!chsc_resp)
712 		return -ENOMEM;
713 	ret = chsc_determine_channel_path_desc(chpid, 0, 0, 0, 0, chsc_resp);
714 	if (ret)
715 		goto out_free;
716 	memcpy(desc, &chsc_resp->data, chsc_resp->length);
717 out_free:
718 	kfree(chsc_resp);
719 	return ret;
720 }
721 
722 static void
723 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
724 			  struct cmg_chars *chars)
725 {
726 	switch (chp->cmg) {
727 	case 2:
728 	case 3:
729 		chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
730 					 GFP_KERNEL);
731 		if (chp->cmg_chars) {
732 			int i, mask;
733 			struct cmg_chars *cmg_chars;
734 
735 			cmg_chars = chp->cmg_chars;
736 			for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
737 				mask = 0x80 >> (i + 3);
738 				if (cmcv & mask)
739 					cmg_chars->values[i] = chars->values[i];
740 				else
741 					cmg_chars->values[i] = 0;
742 			}
743 		}
744 		break;
745 	default:
746 		/* No cmg-dependent data. */
747 		break;
748 	}
749 }
750 
751 int chsc_get_channel_measurement_chars(struct channel_path *chp)
752 {
753 	int ccode, ret;
754 
755 	struct {
756 		struct chsc_header request;
757 		u32 : 24;
758 		u32 first_chpid : 8;
759 		u32 : 24;
760 		u32 last_chpid : 8;
761 		u32 zeroes1;
762 		struct chsc_header response;
763 		u32 zeroes2;
764 		u32 not_valid : 1;
765 		u32 shared : 1;
766 		u32 : 22;
767 		u32 chpid : 8;
768 		u32 cmcv : 5;
769 		u32 : 11;
770 		u32 cmgq : 8;
771 		u32 cmg : 8;
772 		u32 zeroes3;
773 		u32 data[NR_MEASUREMENT_CHARS];
774 	} __attribute__ ((packed)) *scmc_area;
775 
776 	scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
777 	if (!scmc_area)
778 		return -ENOMEM;
779 
780 	scmc_area->request.length = 0x0010;
781 	scmc_area->request.code = 0x0022;
782 
783 	scmc_area->first_chpid = chp->chpid.id;
784 	scmc_area->last_chpid = chp->chpid.id;
785 
786 	ccode = chsc(scmc_area);
787 	if (ccode > 0) {
788 		ret = (ccode == 3) ? -ENODEV : -EBUSY;
789 		goto out;
790 	}
791 
792 	ret = chsc_error_from_response(scmc_area->response.code);
793 	if (ret == 0) {
794 		/* Success. */
795 		if (!scmc_area->not_valid) {
796 			chp->cmg = scmc_area->cmg;
797 			chp->shared = scmc_area->shared;
798 			chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
799 						  (struct cmg_chars *)
800 						  &scmc_area->data);
801 		} else {
802 			chp->cmg = -1;
803 			chp->shared = -1;
804 		}
805 	} else {
806 		CIO_CRW_EVENT(2, "chsc: scmc failed (rc=%04x)\n",
807 			      scmc_area->response.code);
808 	}
809 out:
810 	free_page((unsigned long)scmc_area);
811 	return ret;
812 }
813 
814 int __init chsc_alloc_sei_area(void)
815 {
816 	int ret;
817 
818 	sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
819 	if (!sei_page) {
820 		CIO_MSG_EVENT(0, "Can't allocate page for processing of "
821 			      "chsc machine checks!\n");
822 		return -ENOMEM;
823 	}
824 	ret = crw_register_handler(CRW_RSC_CSS, chsc_process_crw);
825 	if (ret)
826 		kfree(sei_page);
827 	return ret;
828 }
829 
830 void __init chsc_free_sei_area(void)
831 {
832 	crw_unregister_handler(CRW_RSC_CSS);
833 	kfree(sei_page);
834 }
835 
836 int __init
837 chsc_enable_facility(int operation_code)
838 {
839 	int ret;
840 	struct {
841 		struct chsc_header request;
842 		u8 reserved1:4;
843 		u8 format:4;
844 		u8 reserved2;
845 		u16 operation_code;
846 		u32 reserved3;
847 		u32 reserved4;
848 		u32 operation_data_area[252];
849 		struct chsc_header response;
850 		u32 reserved5:4;
851 		u32 format2:4;
852 		u32 reserved6:24;
853 	} __attribute__ ((packed)) *sda_area;
854 
855 	sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
856 	if (!sda_area)
857 		return -ENOMEM;
858 	sda_area->request.length = 0x0400;
859 	sda_area->request.code = 0x0031;
860 	sda_area->operation_code = operation_code;
861 
862 	ret = chsc(sda_area);
863 	if (ret > 0) {
864 		ret = (ret == 3) ? -ENODEV : -EBUSY;
865 		goto out;
866 	}
867 
868 	switch (sda_area->response.code) {
869 	case 0x0101:
870 		ret = -EOPNOTSUPP;
871 		break;
872 	default:
873 		ret = chsc_error_from_response(sda_area->response.code);
874 	}
875 	if (ret != 0)
876 		CIO_CRW_EVENT(2, "chsc: sda (oc=%x) failed (rc=%04x)\n",
877 			      operation_code, sda_area->response.code);
878  out:
879 	free_page((unsigned long)sda_area);
880 	return ret;
881 }
882 
883 struct css_general_char css_general_characteristics;
884 struct css_chsc_char css_chsc_characteristics;
885 
886 int __init
887 chsc_determine_css_characteristics(void)
888 {
889 	int result;
890 	struct {
891 		struct chsc_header request;
892 		u32 reserved1;
893 		u32 reserved2;
894 		u32 reserved3;
895 		struct chsc_header response;
896 		u32 reserved4;
897 		u32 general_char[510];
898 		u32 chsc_char[518];
899 	} __attribute__ ((packed)) *scsc_area;
900 
901 	scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
902 	if (!scsc_area)
903 		return -ENOMEM;
904 
905 	scsc_area->request.length = 0x0010;
906 	scsc_area->request.code = 0x0010;
907 
908 	result = chsc(scsc_area);
909 	if (result) {
910 		result = (result == 3) ? -ENODEV : -EBUSY;
911 		goto exit;
912 	}
913 
914 	result = chsc_error_from_response(scsc_area->response.code);
915 	if (result == 0) {
916 		memcpy(&css_general_characteristics, scsc_area->general_char,
917 		       sizeof(css_general_characteristics));
918 		memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
919 		       sizeof(css_chsc_characteristics));
920 	} else
921 		CIO_CRW_EVENT(2, "chsc: scsc failed (rc=%04x)\n",
922 			      scsc_area->response.code);
923 exit:
924 	free_page ((unsigned long) scsc_area);
925 	return result;
926 }
927 
928 EXPORT_SYMBOL_GPL(css_general_characteristics);
929 EXPORT_SYMBOL_GPL(css_chsc_characteristics);
930 
931 int chsc_sstpc(void *page, unsigned int op, u16 ctrl)
932 {
933 	struct {
934 		struct chsc_header request;
935 		unsigned int rsvd0;
936 		unsigned int op : 8;
937 		unsigned int rsvd1 : 8;
938 		unsigned int ctrl : 16;
939 		unsigned int rsvd2[5];
940 		struct chsc_header response;
941 		unsigned int rsvd3[7];
942 	} __attribute__ ((packed)) *rr;
943 	int rc;
944 
945 	memset(page, 0, PAGE_SIZE);
946 	rr = page;
947 	rr->request.length = 0x0020;
948 	rr->request.code = 0x0033;
949 	rr->op = op;
950 	rr->ctrl = ctrl;
951 	rc = chsc(rr);
952 	if (rc)
953 		return -EIO;
954 	rc = (rr->response.code == 0x0001) ? 0 : -EIO;
955 	return rc;
956 }
957 
958 int chsc_sstpi(void *page, void *result, size_t size)
959 {
960 	struct {
961 		struct chsc_header request;
962 		unsigned int rsvd0[3];
963 		struct chsc_header response;
964 		char data[size];
965 	} __attribute__ ((packed)) *rr;
966 	int rc;
967 
968 	memset(page, 0, PAGE_SIZE);
969 	rr = page;
970 	rr->request.length = 0x0010;
971 	rr->request.code = 0x0038;
972 	rc = chsc(rr);
973 	if (rc)
974 		return -EIO;
975 	memcpy(result, &rr->data, size);
976 	return (rr->response.code == 0x0001) ? 0 : -EIO;
977 }
978 
979