xref: /openbmc/linux/drivers/s390/char/sclp_cmd.c (revision fd589a8f)
1 /*
2  * Copyright IBM Corp. 2007, 2009
3  *
4  * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
5  *	      Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
6  */
7 
8 #define KMSG_COMPONENT "sclp_cmd"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10 
11 #include <linux/completion.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <linux/mm.h>
18 #include <linux/mmzone.h>
19 #include <linux/memory.h>
20 #include <linux/platform_device.h>
21 #include <asm/chpid.h>
22 #include <asm/sclp.h>
23 #include <asm/setup.h>
24 
25 #include "sclp.h"
26 
27 #define SCLP_CMDW_READ_SCP_INFO		0x00020001
28 #define SCLP_CMDW_READ_SCP_INFO_FORCED	0x00120001
29 
30 struct read_info_sccb {
31 	struct	sccb_header header;	/* 0-7 */
32 	u16	rnmax;			/* 8-9 */
33 	u8	rnsize;			/* 10 */
34 	u8	_reserved0[24 - 11];	/* 11-15 */
35 	u8	loadparm[8];		/* 24-31 */
36 	u8	_reserved1[48 - 32];	/* 32-47 */
37 	u64	facilities;		/* 48-55 */
38 	u8	_reserved2[84 - 56];	/* 56-83 */
39 	u8	fac84;			/* 84 */
40 	u8	_reserved3[91 - 85];	/* 85-90 */
41 	u8	flags;			/* 91 */
42 	u8	_reserved4[100 - 92];	/* 92-99 */
43 	u32	rnsize2;		/* 100-103 */
44 	u64	rnmax2;			/* 104-111 */
45 	u8	_reserved5[4096 - 112];	/* 112-4095 */
46 } __attribute__((packed, aligned(PAGE_SIZE)));
47 
48 static struct read_info_sccb __initdata early_read_info_sccb;
49 static int __initdata early_read_info_sccb_valid;
50 
51 u64 sclp_facilities;
52 static u8 sclp_fac84;
53 static unsigned long long rzm;
54 static unsigned long long rnmax;
55 
56 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
57 {
58 	int rc;
59 
60 	__ctl_set_bit(0, 9);
61 	rc = sclp_service_call(cmd, sccb);
62 	if (rc)
63 		goto out;
64 	__load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
65 			PSW_MASK_WAIT | PSW_DEFAULT_KEY);
66 	local_irq_disable();
67 out:
68 	/* Contents of the sccb might have changed. */
69 	barrier();
70 	__ctl_clear_bit(0, 9);
71 	return rc;
72 }
73 
74 static void __init sclp_read_info_early(void)
75 {
76 	int rc;
77 	int i;
78 	struct read_info_sccb *sccb;
79 	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
80 				  SCLP_CMDW_READ_SCP_INFO};
81 
82 	sccb = &early_read_info_sccb;
83 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
84 		do {
85 			memset(sccb, 0, sizeof(*sccb));
86 			sccb->header.length = sizeof(*sccb);
87 			sccb->header.control_mask[2] = 0x80;
88 			rc = sclp_cmd_sync_early(commands[i], sccb);
89 		} while (rc == -EBUSY);
90 
91 		if (rc)
92 			break;
93 		if (sccb->header.response_code == 0x10) {
94 			early_read_info_sccb_valid = 1;
95 			break;
96 		}
97 		if (sccb->header.response_code != 0x1f0)
98 			break;
99 	}
100 }
101 
102 void __init sclp_facilities_detect(void)
103 {
104 	struct read_info_sccb *sccb;
105 
106 	sclp_read_info_early();
107 	if (!early_read_info_sccb_valid)
108 		return;
109 
110 	sccb = &early_read_info_sccb;
111 	sclp_facilities = sccb->facilities;
112 	sclp_fac84 = sccb->fac84;
113 	rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
114 	rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
115 	rzm <<= 20;
116 }
117 
118 unsigned long long sclp_get_rnmax(void)
119 {
120 	return rnmax;
121 }
122 
123 unsigned long long sclp_get_rzm(void)
124 {
125 	return rzm;
126 }
127 
128 /*
129  * This function will be called after sclp_facilities_detect(), which gets
130  * called from early.c code. Therefore the sccb should have valid contents.
131  */
132 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
133 {
134 	struct read_info_sccb *sccb;
135 
136 	if (!early_read_info_sccb_valid)
137 		return;
138 	sccb = &early_read_info_sccb;
139 	info->is_valid = 1;
140 	if (sccb->flags & 0x2)
141 		info->has_dump = 1;
142 	memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
143 }
144 
145 static void sclp_sync_callback(struct sclp_req *req, void *data)
146 {
147 	struct completion *completion = data;
148 
149 	complete(completion);
150 }
151 
152 static int do_sync_request(sclp_cmdw_t cmd, void *sccb)
153 {
154 	struct completion completion;
155 	struct sclp_req *request;
156 	int rc;
157 
158 	request = kzalloc(sizeof(*request), GFP_KERNEL);
159 	if (!request)
160 		return -ENOMEM;
161 	request->command = cmd;
162 	request->sccb = sccb;
163 	request->status = SCLP_REQ_FILLED;
164 	request->callback = sclp_sync_callback;
165 	request->callback_data = &completion;
166 	init_completion(&completion);
167 
168 	/* Perform sclp request. */
169 	rc = sclp_add_request(request);
170 	if (rc)
171 		goto out;
172 	wait_for_completion(&completion);
173 
174 	/* Check response. */
175 	if (request->status != SCLP_REQ_DONE) {
176 		pr_warning("sync request failed (cmd=0x%08x, "
177 			   "status=0x%02x)\n", cmd, request->status);
178 		rc = -EIO;
179 	}
180 out:
181 	kfree(request);
182 	return rc;
183 }
184 
185 /*
186  * CPU configuration related functions.
187  */
188 
189 #define SCLP_CMDW_READ_CPU_INFO		0x00010001
190 #define SCLP_CMDW_CONFIGURE_CPU		0x00110001
191 #define SCLP_CMDW_DECONFIGURE_CPU	0x00100001
192 
193 struct read_cpu_info_sccb {
194 	struct	sccb_header header;
195 	u16	nr_configured;
196 	u16	offset_configured;
197 	u16	nr_standby;
198 	u16	offset_standby;
199 	u8	reserved[4096 - 16];
200 } __attribute__((packed, aligned(PAGE_SIZE)));
201 
202 static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
203 			       struct read_cpu_info_sccb *sccb)
204 {
205 	char *page = (char *) sccb;
206 
207 	memset(info, 0, sizeof(*info));
208 	info->configured = sccb->nr_configured;
209 	info->standby = sccb->nr_standby;
210 	info->combined = sccb->nr_configured + sccb->nr_standby;
211 	info->has_cpu_type = sclp_fac84 & 0x1;
212 	memcpy(&info->cpu, page + sccb->offset_configured,
213 	       info->combined * sizeof(struct sclp_cpu_entry));
214 }
215 
216 int sclp_get_cpu_info(struct sclp_cpu_info *info)
217 {
218 	int rc;
219 	struct read_cpu_info_sccb *sccb;
220 
221 	if (!SCLP_HAS_CPU_INFO)
222 		return -EOPNOTSUPP;
223 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
224 	if (!sccb)
225 		return -ENOMEM;
226 	sccb->header.length = sizeof(*sccb);
227 	rc = do_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
228 	if (rc)
229 		goto out;
230 	if (sccb->header.response_code != 0x0010) {
231 		pr_warning("readcpuinfo failed (response=0x%04x)\n",
232 			   sccb->header.response_code);
233 		rc = -EIO;
234 		goto out;
235 	}
236 	sclp_fill_cpu_info(info, sccb);
237 out:
238 	free_page((unsigned long) sccb);
239 	return rc;
240 }
241 
242 struct cpu_configure_sccb {
243 	struct sccb_header header;
244 } __attribute__((packed, aligned(8)));
245 
246 static int do_cpu_configure(sclp_cmdw_t cmd)
247 {
248 	struct cpu_configure_sccb *sccb;
249 	int rc;
250 
251 	if (!SCLP_HAS_CPU_RECONFIG)
252 		return -EOPNOTSUPP;
253 	/*
254 	 * This is not going to cross a page boundary since we force
255 	 * kmalloc to have a minimum alignment of 8 bytes on s390.
256 	 */
257 	sccb = kzalloc(sizeof(*sccb), GFP_KERNEL | GFP_DMA);
258 	if (!sccb)
259 		return -ENOMEM;
260 	sccb->header.length = sizeof(*sccb);
261 	rc = do_sync_request(cmd, sccb);
262 	if (rc)
263 		goto out;
264 	switch (sccb->header.response_code) {
265 	case 0x0020:
266 	case 0x0120:
267 		break;
268 	default:
269 		pr_warning("configure cpu failed (cmd=0x%08x, "
270 			   "response=0x%04x)\n", cmd,
271 			   sccb->header.response_code);
272 		rc = -EIO;
273 		break;
274 	}
275 out:
276 	kfree(sccb);
277 	return rc;
278 }
279 
280 int sclp_cpu_configure(u8 cpu)
281 {
282 	return do_cpu_configure(SCLP_CMDW_CONFIGURE_CPU | cpu << 8);
283 }
284 
285 int sclp_cpu_deconfigure(u8 cpu)
286 {
287 	return do_cpu_configure(SCLP_CMDW_DECONFIGURE_CPU | cpu << 8);
288 }
289 
290 #ifdef CONFIG_MEMORY_HOTPLUG
291 
292 static DEFINE_MUTEX(sclp_mem_mutex);
293 static LIST_HEAD(sclp_mem_list);
294 static u8 sclp_max_storage_id;
295 static unsigned long sclp_storage_ids[256 / BITS_PER_LONG];
296 static int sclp_mem_state_changed;
297 
298 struct memory_increment {
299 	struct list_head list;
300 	u16 rn;
301 	int standby;
302 	int usecount;
303 };
304 
305 struct assign_storage_sccb {
306 	struct sccb_header header;
307 	u16 rn;
308 } __packed;
309 
310 static unsigned long long rn2addr(u16 rn)
311 {
312 	return (unsigned long long) (rn - 1) * rzm;
313 }
314 
315 static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
316 {
317 	struct assign_storage_sccb *sccb;
318 	int rc;
319 
320 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
321 	if (!sccb)
322 		return -ENOMEM;
323 	sccb->header.length = PAGE_SIZE;
324 	sccb->rn = rn;
325 	rc = do_sync_request(cmd, sccb);
326 	if (rc)
327 		goto out;
328 	switch (sccb->header.response_code) {
329 	case 0x0020:
330 	case 0x0120:
331 		break;
332 	default:
333 		pr_warning("assign storage failed (cmd=0x%08x, "
334 			   "response=0x%04x, rn=0x%04x)\n", cmd,
335 			   sccb->header.response_code, rn);
336 		rc = -EIO;
337 		break;
338 	}
339 out:
340 	free_page((unsigned long) sccb);
341 	return rc;
342 }
343 
344 static int sclp_assign_storage(u16 rn)
345 {
346 	return do_assign_storage(0x000d0001, rn);
347 }
348 
349 static int sclp_unassign_storage(u16 rn)
350 {
351 	return do_assign_storage(0x000c0001, rn);
352 }
353 
354 struct attach_storage_sccb {
355 	struct sccb_header header;
356 	u16 :16;
357 	u16 assigned;
358 	u32 :32;
359 	u32 entries[0];
360 } __packed;
361 
362 static int sclp_attach_storage(u8 id)
363 {
364 	struct attach_storage_sccb *sccb;
365 	int rc;
366 	int i;
367 
368 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
369 	if (!sccb)
370 		return -ENOMEM;
371 	sccb->header.length = PAGE_SIZE;
372 	rc = do_sync_request(0x00080001 | id << 8, sccb);
373 	if (rc)
374 		goto out;
375 	switch (sccb->header.response_code) {
376 	case 0x0020:
377 		set_bit(id, sclp_storage_ids);
378 		for (i = 0; i < sccb->assigned; i++)
379 			sclp_unassign_storage(sccb->entries[i] >> 16);
380 		break;
381 	default:
382 		rc = -EIO;
383 		break;
384 	}
385 out:
386 	free_page((unsigned long) sccb);
387 	return rc;
388 }
389 
390 static int sclp_mem_change_state(unsigned long start, unsigned long size,
391 				 int online)
392 {
393 	struct memory_increment *incr;
394 	unsigned long long istart;
395 	int rc = 0;
396 
397 	list_for_each_entry(incr, &sclp_mem_list, list) {
398 		istart = rn2addr(incr->rn);
399 		if (start + size - 1 < istart)
400 			break;
401 		if (start > istart + rzm - 1)
402 			continue;
403 		if (online) {
404 			if (incr->usecount++)
405 				continue;
406 			/*
407 			 * Don't break the loop if one assign fails. Loop may
408 			 * be walked again on CANCEL and we can't save
409 			 * information if state changed before or not.
410 			 * So continue and increase usecount for all increments.
411 			 */
412 			rc |= sclp_assign_storage(incr->rn);
413 		} else {
414 			if (--incr->usecount)
415 				continue;
416 			sclp_unassign_storage(incr->rn);
417 		}
418 	}
419 	return rc ? -EIO : 0;
420 }
421 
422 static int sclp_mem_notifier(struct notifier_block *nb,
423 			     unsigned long action, void *data)
424 {
425 	unsigned long start, size;
426 	struct memory_notify *arg;
427 	unsigned char id;
428 	int rc = 0;
429 
430 	arg = data;
431 	start = arg->start_pfn << PAGE_SHIFT;
432 	size = arg->nr_pages << PAGE_SHIFT;
433 	mutex_lock(&sclp_mem_mutex);
434 	for (id = 0; id <= sclp_max_storage_id; id++)
435 		if (!test_bit(id, sclp_storage_ids))
436 			sclp_attach_storage(id);
437 	switch (action) {
438 	case MEM_ONLINE:
439 	case MEM_GOING_OFFLINE:
440 	case MEM_CANCEL_OFFLINE:
441 		break;
442 	case MEM_GOING_ONLINE:
443 		rc = sclp_mem_change_state(start, size, 1);
444 		break;
445 	case MEM_CANCEL_ONLINE:
446 		sclp_mem_change_state(start, size, 0);
447 		break;
448 	case MEM_OFFLINE:
449 		sclp_mem_change_state(start, size, 0);
450 		break;
451 	default:
452 		rc = -EINVAL;
453 		break;
454 	}
455 	if (!rc)
456 		sclp_mem_state_changed = 1;
457 	mutex_unlock(&sclp_mem_mutex);
458 	return rc ? NOTIFY_BAD : NOTIFY_OK;
459 }
460 
461 static struct notifier_block sclp_mem_nb = {
462 	.notifier_call = sclp_mem_notifier,
463 };
464 
465 static void __init add_memory_merged(u16 rn)
466 {
467 	static u16 first_rn, num;
468 	unsigned long long start, size;
469 
470 	if (rn && first_rn && (first_rn + num == rn)) {
471 		num++;
472 		return;
473 	}
474 	if (!first_rn)
475 		goto skip_add;
476 	start = rn2addr(first_rn);
477 	size = (unsigned long long ) num * rzm;
478 	if (start >= VMEM_MAX_PHYS)
479 		goto skip_add;
480 	if (start + size > VMEM_MAX_PHYS)
481 		size = VMEM_MAX_PHYS - start;
482 	if (memory_end_set && (start >= memory_end))
483 		goto skip_add;
484 	if (memory_end_set && (start + size > memory_end))
485 		size = memory_end - start;
486 	add_memory(0, start, size);
487 skip_add:
488 	first_rn = rn;
489 	num = 1;
490 }
491 
492 static void __init sclp_add_standby_memory(void)
493 {
494 	struct memory_increment *incr;
495 
496 	list_for_each_entry(incr, &sclp_mem_list, list)
497 		if (incr->standby)
498 			add_memory_merged(incr->rn);
499 	add_memory_merged(0);
500 }
501 
502 static void __init insert_increment(u16 rn, int standby, int assigned)
503 {
504 	struct memory_increment *incr, *new_incr;
505 	struct list_head *prev;
506 	u16 last_rn;
507 
508 	new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
509 	if (!new_incr)
510 		return;
511 	new_incr->rn = rn;
512 	new_incr->standby = standby;
513 	last_rn = 0;
514 	prev = &sclp_mem_list;
515 	list_for_each_entry(incr, &sclp_mem_list, list) {
516 		if (assigned && incr->rn > rn)
517 			break;
518 		if (!assigned && incr->rn - last_rn > 1)
519 			break;
520 		last_rn = incr->rn;
521 		prev = &incr->list;
522 	}
523 	if (!assigned)
524 		new_incr->rn = last_rn + 1;
525 	if (new_incr->rn > rnmax) {
526 		kfree(new_incr);
527 		return;
528 	}
529 	list_add(&new_incr->list, prev);
530 }
531 
532 static int sclp_mem_freeze(struct device *dev)
533 {
534 	if (!sclp_mem_state_changed)
535 		return 0;
536 	pr_err("Memory hotplug state changed, suspend refused.\n");
537 	return -EPERM;
538 }
539 
540 struct read_storage_sccb {
541 	struct sccb_header header;
542 	u16 max_id;
543 	u16 assigned;
544 	u16 standby;
545 	u16 :16;
546 	u32 entries[0];
547 } __packed;
548 
549 static struct dev_pm_ops sclp_mem_pm_ops = {
550 	.freeze		= sclp_mem_freeze,
551 };
552 
553 static struct platform_driver sclp_mem_pdrv = {
554 	.driver = {
555 		.name	= "sclp_mem",
556 		.pm	= &sclp_mem_pm_ops,
557 	},
558 };
559 
560 static int __init sclp_detect_standby_memory(void)
561 {
562 	struct platform_device *sclp_pdev;
563 	struct read_storage_sccb *sccb;
564 	int i, id, assigned, rc;
565 
566 	if (!early_read_info_sccb_valid)
567 		return 0;
568 	if ((sclp_facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
569 		return 0;
570 	rc = -ENOMEM;
571 	sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
572 	if (!sccb)
573 		goto out;
574 	assigned = 0;
575 	for (id = 0; id <= sclp_max_storage_id; id++) {
576 		memset(sccb, 0, PAGE_SIZE);
577 		sccb->header.length = PAGE_SIZE;
578 		rc = do_sync_request(0x00040001 | id << 8, sccb);
579 		if (rc)
580 			goto out;
581 		switch (sccb->header.response_code) {
582 		case 0x0010:
583 			set_bit(id, sclp_storage_ids);
584 			for (i = 0; i < sccb->assigned; i++) {
585 				if (!sccb->entries[i])
586 					continue;
587 				assigned++;
588 				insert_increment(sccb->entries[i] >> 16, 0, 1);
589 			}
590 			break;
591 		case 0x0310:
592 			break;
593 		case 0x0410:
594 			for (i = 0; i < sccb->assigned; i++) {
595 				if (!sccb->entries[i])
596 					continue;
597 				assigned++;
598 				insert_increment(sccb->entries[i] >> 16, 1, 1);
599 			}
600 			break;
601 		default:
602 			rc = -EIO;
603 			break;
604 		}
605 		if (!rc)
606 			sclp_max_storage_id = sccb->max_id;
607 	}
608 	if (rc || list_empty(&sclp_mem_list))
609 		goto out;
610 	for (i = 1; i <= rnmax - assigned; i++)
611 		insert_increment(0, 1, 0);
612 	rc = register_memory_notifier(&sclp_mem_nb);
613 	if (rc)
614 		goto out;
615 	rc = platform_driver_register(&sclp_mem_pdrv);
616 	if (rc)
617 		goto out;
618 	sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0);
619 	rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0;
620 	if (rc)
621 		goto out_driver;
622 	sclp_add_standby_memory();
623 	goto out;
624 out_driver:
625 	platform_driver_unregister(&sclp_mem_pdrv);
626 out:
627 	free_page((unsigned long) sccb);
628 	return rc;
629 }
630 __initcall(sclp_detect_standby_memory);
631 
632 #endif /* CONFIG_MEMORY_HOTPLUG */
633 
634 /*
635  * Channel path configuration related functions.
636  */
637 
638 #define SCLP_CMDW_CONFIGURE_CHPATH		0x000f0001
639 #define SCLP_CMDW_DECONFIGURE_CHPATH		0x000e0001
640 #define SCLP_CMDW_READ_CHPATH_INFORMATION	0x00030001
641 
642 struct chp_cfg_sccb {
643 	struct sccb_header header;
644 	u8 ccm;
645 	u8 reserved[6];
646 	u8 cssid;
647 } __attribute__((packed));
648 
649 static int do_chp_configure(sclp_cmdw_t cmd)
650 {
651 	struct chp_cfg_sccb *sccb;
652 	int rc;
653 
654 	if (!SCLP_HAS_CHP_RECONFIG)
655 		return -EOPNOTSUPP;
656 	/* Prepare sccb. */
657 	sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
658 	if (!sccb)
659 		return -ENOMEM;
660 	sccb->header.length = sizeof(*sccb);
661 	rc = do_sync_request(cmd, sccb);
662 	if (rc)
663 		goto out;
664 	switch (sccb->header.response_code) {
665 	case 0x0020:
666 	case 0x0120:
667 	case 0x0440:
668 	case 0x0450:
669 		break;
670 	default:
671 		pr_warning("configure channel-path failed "
672 			   "(cmd=0x%08x, response=0x%04x)\n", cmd,
673 			   sccb->header.response_code);
674 		rc = -EIO;
675 		break;
676 	}
677 out:
678 	free_page((unsigned long) sccb);
679 	return rc;
680 }
681 
682 /**
683  * sclp_chp_configure - perform configure channel-path sclp command
684  * @chpid: channel-path ID
685  *
686  * Perform configure channel-path command sclp command for specified chpid.
687  * Return 0 after command successfully finished, non-zero otherwise.
688  */
689 int sclp_chp_configure(struct chp_id chpid)
690 {
691 	return do_chp_configure(SCLP_CMDW_CONFIGURE_CHPATH | chpid.id << 8);
692 }
693 
694 /**
695  * sclp_chp_deconfigure - perform deconfigure channel-path sclp command
696  * @chpid: channel-path ID
697  *
698  * Perform deconfigure channel-path command sclp command for specified chpid
699  * and wait for completion. On success return 0. Return non-zero otherwise.
700  */
701 int sclp_chp_deconfigure(struct chp_id chpid)
702 {
703 	return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8);
704 }
705 
706 struct chp_info_sccb {
707 	struct sccb_header header;
708 	u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
709 	u8 standby[SCLP_CHP_INFO_MASK_SIZE];
710 	u8 configured[SCLP_CHP_INFO_MASK_SIZE];
711 	u8 ccm;
712 	u8 reserved[6];
713 	u8 cssid;
714 } __attribute__((packed));
715 
716 /**
717  * sclp_chp_read_info - perform read channel-path information sclp command
718  * @info: resulting channel-path information data
719  *
720  * Perform read channel-path information sclp command and wait for completion.
721  * On success, store channel-path information in @info and return 0. Return
722  * non-zero otherwise.
723  */
724 int sclp_chp_read_info(struct sclp_chp_info *info)
725 {
726 	struct chp_info_sccb *sccb;
727 	int rc;
728 
729 	if (!SCLP_HAS_CHP_INFO)
730 		return -EOPNOTSUPP;
731 	/* Prepare sccb. */
732 	sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
733 	if (!sccb)
734 		return -ENOMEM;
735 	sccb->header.length = sizeof(*sccb);
736 	rc = do_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
737 	if (rc)
738 		goto out;
739 	if (sccb->header.response_code != 0x0010) {
740 		pr_warning("read channel-path info failed "
741 			   "(response=0x%04x)\n", sccb->header.response_code);
742 		rc = -EIO;
743 		goto out;
744 	}
745 	memcpy(info->recognized, sccb->recognized, SCLP_CHP_INFO_MASK_SIZE);
746 	memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE);
747 	memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE);
748 out:
749 	free_page((unsigned long) sccb);
750 	return rc;
751 }
752