xref: /linux/drivers/s390/char/sclp_cmd.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
65 			PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
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.function_code = 0x80;
88 			sccb->header.control_mask[2] = 0x80;
89 			rc = sclp_cmd_sync_early(commands[i], sccb);
90 		} while (rc == -EBUSY);
91 
92 		if (rc)
93 			break;
94 		if (sccb->header.response_code == 0x10) {
95 			early_read_info_sccb_valid = 1;
96 			break;
97 		}
98 		if (sccb->header.response_code != 0x1f0)
99 			break;
100 	}
101 }
102 
103 void __init sclp_facilities_detect(void)
104 {
105 	struct read_info_sccb *sccb;
106 
107 	sclp_read_info_early();
108 	if (!early_read_info_sccb_valid)
109 		return;
110 
111 	sccb = &early_read_info_sccb;
112 	sclp_facilities = sccb->facilities;
113 	sclp_fac84 = sccb->fac84;
114 	rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
115 	rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
116 	rzm <<= 20;
117 }
118 
119 unsigned long long sclp_get_rnmax(void)
120 {
121 	return rnmax;
122 }
123 
124 unsigned long long sclp_get_rzm(void)
125 {
126 	return rzm;
127 }
128 
129 /*
130  * This function will be called after sclp_facilities_detect(), which gets
131  * called from early.c code. Therefore the sccb should have valid contents.
132  */
133 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
134 {
135 	struct read_info_sccb *sccb;
136 
137 	if (!early_read_info_sccb_valid)
138 		return;
139 	sccb = &early_read_info_sccb;
140 	info->is_valid = 1;
141 	if (sccb->flags & 0x2)
142 		info->has_dump = 1;
143 	memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
144 }
145 
146 static void sclp_sync_callback(struct sclp_req *req, void *data)
147 {
148 	struct completion *completion = data;
149 
150 	complete(completion);
151 }
152 
153 static int do_sync_request(sclp_cmdw_t cmd, void *sccb)
154 {
155 	struct completion completion;
156 	struct sclp_req *request;
157 	int rc;
158 
159 	request = kzalloc(sizeof(*request), GFP_KERNEL);
160 	if (!request)
161 		return -ENOMEM;
162 	request->command = cmd;
163 	request->sccb = sccb;
164 	request->status = SCLP_REQ_FILLED;
165 	request->callback = sclp_sync_callback;
166 	request->callback_data = &completion;
167 	init_completion(&completion);
168 
169 	/* Perform sclp request. */
170 	rc = sclp_add_request(request);
171 	if (rc)
172 		goto out;
173 	wait_for_completion(&completion);
174 
175 	/* Check response. */
176 	if (request->status != SCLP_REQ_DONE) {
177 		pr_warning("sync request failed (cmd=0x%08x, "
178 			   "status=0x%02x)\n", cmd, request->status);
179 		rc = -EIO;
180 	}
181 out:
182 	kfree(request);
183 	return rc;
184 }
185 
186 /*
187  * CPU configuration related functions.
188  */
189 
190 #define SCLP_CMDW_READ_CPU_INFO		0x00010001
191 #define SCLP_CMDW_CONFIGURE_CPU		0x00110001
192 #define SCLP_CMDW_DECONFIGURE_CPU	0x00100001
193 
194 struct read_cpu_info_sccb {
195 	struct	sccb_header header;
196 	u16	nr_configured;
197 	u16	offset_configured;
198 	u16	nr_standby;
199 	u16	offset_standby;
200 	u8	reserved[4096 - 16];
201 } __attribute__((packed, aligned(PAGE_SIZE)));
202 
203 static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
204 			       struct read_cpu_info_sccb *sccb)
205 {
206 	char *page = (char *) sccb;
207 
208 	memset(info, 0, sizeof(*info));
209 	info->configured = sccb->nr_configured;
210 	info->standby = sccb->nr_standby;
211 	info->combined = sccb->nr_configured + sccb->nr_standby;
212 	info->has_cpu_type = sclp_fac84 & 0x1;
213 	memcpy(&info->cpu, page + sccb->offset_configured,
214 	       info->combined * sizeof(struct sclp_cpu_entry));
215 }
216 
217 int sclp_get_cpu_info(struct sclp_cpu_info *info)
218 {
219 	int rc;
220 	struct read_cpu_info_sccb *sccb;
221 
222 	if (!SCLP_HAS_CPU_INFO)
223 		return -EOPNOTSUPP;
224 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
225 	if (!sccb)
226 		return -ENOMEM;
227 	sccb->header.length = sizeof(*sccb);
228 	rc = do_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
229 	if (rc)
230 		goto out;
231 	if (sccb->header.response_code != 0x0010) {
232 		pr_warning("readcpuinfo failed (response=0x%04x)\n",
233 			   sccb->header.response_code);
234 		rc = -EIO;
235 		goto out;
236 	}
237 	sclp_fill_cpu_info(info, sccb);
238 out:
239 	free_page((unsigned long) sccb);
240 	return rc;
241 }
242 
243 struct cpu_configure_sccb {
244 	struct sccb_header header;
245 } __attribute__((packed, aligned(8)));
246 
247 static int do_cpu_configure(sclp_cmdw_t cmd)
248 {
249 	struct cpu_configure_sccb *sccb;
250 	int rc;
251 
252 	if (!SCLP_HAS_CPU_RECONFIG)
253 		return -EOPNOTSUPP;
254 	/*
255 	 * This is not going to cross a page boundary since we force
256 	 * kmalloc to have a minimum alignment of 8 bytes on s390.
257 	 */
258 	sccb = kzalloc(sizeof(*sccb), GFP_KERNEL | GFP_DMA);
259 	if (!sccb)
260 		return -ENOMEM;
261 	sccb->header.length = sizeof(*sccb);
262 	rc = do_sync_request(cmd, sccb);
263 	if (rc)
264 		goto out;
265 	switch (sccb->header.response_code) {
266 	case 0x0020:
267 	case 0x0120:
268 		break;
269 	default:
270 		pr_warning("configure cpu failed (cmd=0x%08x, "
271 			   "response=0x%04x)\n", cmd,
272 			   sccb->header.response_code);
273 		rc = -EIO;
274 		break;
275 	}
276 out:
277 	kfree(sccb);
278 	return rc;
279 }
280 
281 int sclp_cpu_configure(u8 cpu)
282 {
283 	return do_cpu_configure(SCLP_CMDW_CONFIGURE_CPU | cpu << 8);
284 }
285 
286 int sclp_cpu_deconfigure(u8 cpu)
287 {
288 	return do_cpu_configure(SCLP_CMDW_DECONFIGURE_CPU | cpu << 8);
289 }
290 
291 #ifdef CONFIG_MEMORY_HOTPLUG
292 
293 static DEFINE_MUTEX(sclp_mem_mutex);
294 static LIST_HEAD(sclp_mem_list);
295 static u8 sclp_max_storage_id;
296 static unsigned long sclp_storage_ids[256 / BITS_PER_LONG];
297 static int sclp_mem_state_changed;
298 
299 struct memory_increment {
300 	struct list_head list;
301 	u16 rn;
302 	int standby;
303 	int usecount;
304 };
305 
306 struct assign_storage_sccb {
307 	struct sccb_header header;
308 	u16 rn;
309 } __packed;
310 
311 int arch_get_memory_phys_device(unsigned long start_pfn)
312 {
313 	if (!rzm)
314 		return 0;
315 	return PFN_PHYS(start_pfn) >> ilog2(rzm);
316 }
317 
318 static unsigned long long rn2addr(u16 rn)
319 {
320 	return (unsigned long long) (rn - 1) * rzm;
321 }
322 
323 static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
324 {
325 	struct assign_storage_sccb *sccb;
326 	int rc;
327 
328 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
329 	if (!sccb)
330 		return -ENOMEM;
331 	sccb->header.length = PAGE_SIZE;
332 	sccb->rn = rn;
333 	rc = do_sync_request(cmd, sccb);
334 	if (rc)
335 		goto out;
336 	switch (sccb->header.response_code) {
337 	case 0x0020:
338 	case 0x0120:
339 		break;
340 	default:
341 		pr_warning("assign storage failed (cmd=0x%08x, "
342 			   "response=0x%04x, rn=0x%04x)\n", cmd,
343 			   sccb->header.response_code, rn);
344 		rc = -EIO;
345 		break;
346 	}
347 out:
348 	free_page((unsigned long) sccb);
349 	return rc;
350 }
351 
352 static int sclp_assign_storage(u16 rn)
353 {
354 	return do_assign_storage(0x000d0001, rn);
355 }
356 
357 static int sclp_unassign_storage(u16 rn)
358 {
359 	return do_assign_storage(0x000c0001, rn);
360 }
361 
362 struct attach_storage_sccb {
363 	struct sccb_header header;
364 	u16 :16;
365 	u16 assigned;
366 	u32 :32;
367 	u32 entries[0];
368 } __packed;
369 
370 static int sclp_attach_storage(u8 id)
371 {
372 	struct attach_storage_sccb *sccb;
373 	int rc;
374 	int i;
375 
376 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
377 	if (!sccb)
378 		return -ENOMEM;
379 	sccb->header.length = PAGE_SIZE;
380 	rc = do_sync_request(0x00080001 | id << 8, sccb);
381 	if (rc)
382 		goto out;
383 	switch (sccb->header.response_code) {
384 	case 0x0020:
385 		set_bit(id, sclp_storage_ids);
386 		for (i = 0; i < sccb->assigned; i++) {
387 			if (sccb->entries[i])
388 				sclp_unassign_storage(sccb->entries[i] >> 16);
389 		}
390 		break;
391 	default:
392 		rc = -EIO;
393 		break;
394 	}
395 out:
396 	free_page((unsigned long) sccb);
397 	return rc;
398 }
399 
400 static int sclp_mem_change_state(unsigned long start, unsigned long size,
401 				 int online)
402 {
403 	struct memory_increment *incr;
404 	unsigned long long istart;
405 	int rc = 0;
406 
407 	list_for_each_entry(incr, &sclp_mem_list, list) {
408 		istart = rn2addr(incr->rn);
409 		if (start + size - 1 < istart)
410 			break;
411 		if (start > istart + rzm - 1)
412 			continue;
413 		if (online) {
414 			if (incr->usecount++)
415 				continue;
416 			/*
417 			 * Don't break the loop if one assign fails. Loop may
418 			 * be walked again on CANCEL and we can't save
419 			 * information if state changed before or not.
420 			 * So continue and increase usecount for all increments.
421 			 */
422 			rc |= sclp_assign_storage(incr->rn);
423 		} else {
424 			if (--incr->usecount)
425 				continue;
426 			sclp_unassign_storage(incr->rn);
427 		}
428 	}
429 	return rc ? -EIO : 0;
430 }
431 
432 static int sclp_mem_notifier(struct notifier_block *nb,
433 			     unsigned long action, void *data)
434 {
435 	unsigned long start, size;
436 	struct memory_notify *arg;
437 	unsigned char id;
438 	int rc = 0;
439 
440 	arg = data;
441 	start = arg->start_pfn << PAGE_SHIFT;
442 	size = arg->nr_pages << PAGE_SHIFT;
443 	mutex_lock(&sclp_mem_mutex);
444 	for (id = 0; id <= sclp_max_storage_id; id++)
445 		if (!test_bit(id, sclp_storage_ids))
446 			sclp_attach_storage(id);
447 	switch (action) {
448 	case MEM_ONLINE:
449 	case MEM_GOING_OFFLINE:
450 	case MEM_CANCEL_OFFLINE:
451 		break;
452 	case MEM_GOING_ONLINE:
453 		rc = sclp_mem_change_state(start, size, 1);
454 		break;
455 	case MEM_CANCEL_ONLINE:
456 		sclp_mem_change_state(start, size, 0);
457 		break;
458 	case MEM_OFFLINE:
459 		sclp_mem_change_state(start, size, 0);
460 		break;
461 	default:
462 		rc = -EINVAL;
463 		break;
464 	}
465 	if (!rc)
466 		sclp_mem_state_changed = 1;
467 	mutex_unlock(&sclp_mem_mutex);
468 	return rc ? NOTIFY_BAD : NOTIFY_OK;
469 }
470 
471 static struct notifier_block sclp_mem_nb = {
472 	.notifier_call = sclp_mem_notifier,
473 };
474 
475 static void __init add_memory_merged(u16 rn)
476 {
477 	static u16 first_rn, num;
478 	unsigned long long start, size;
479 
480 	if (rn && first_rn && (first_rn + num == rn)) {
481 		num++;
482 		return;
483 	}
484 	if (!first_rn)
485 		goto skip_add;
486 	start = rn2addr(first_rn);
487 	size = (unsigned long long ) num * rzm;
488 	if (start >= VMEM_MAX_PHYS)
489 		goto skip_add;
490 	if (start + size > VMEM_MAX_PHYS)
491 		size = VMEM_MAX_PHYS - start;
492 	if (memory_end_set && (start >= memory_end))
493 		goto skip_add;
494 	if (memory_end_set && (start + size > memory_end))
495 		size = memory_end - start;
496 	add_memory(0, start, size);
497 skip_add:
498 	first_rn = rn;
499 	num = 1;
500 }
501 
502 static void __init sclp_add_standby_memory(void)
503 {
504 	struct memory_increment *incr;
505 
506 	list_for_each_entry(incr, &sclp_mem_list, list)
507 		if (incr->standby)
508 			add_memory_merged(incr->rn);
509 	add_memory_merged(0);
510 }
511 
512 static void __init insert_increment(u16 rn, int standby, int assigned)
513 {
514 	struct memory_increment *incr, *new_incr;
515 	struct list_head *prev;
516 	u16 last_rn;
517 
518 	new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
519 	if (!new_incr)
520 		return;
521 	new_incr->rn = rn;
522 	new_incr->standby = standby;
523 	if (!standby)
524 		new_incr->usecount = 1;
525 	last_rn = 0;
526 	prev = &sclp_mem_list;
527 	list_for_each_entry(incr, &sclp_mem_list, list) {
528 		if (assigned && incr->rn > rn)
529 			break;
530 		if (!assigned && incr->rn - last_rn > 1)
531 			break;
532 		last_rn = incr->rn;
533 		prev = &incr->list;
534 	}
535 	if (!assigned)
536 		new_incr->rn = last_rn + 1;
537 	if (new_incr->rn > rnmax) {
538 		kfree(new_incr);
539 		return;
540 	}
541 	list_add(&new_incr->list, prev);
542 }
543 
544 static int sclp_mem_freeze(struct device *dev)
545 {
546 	if (!sclp_mem_state_changed)
547 		return 0;
548 	pr_err("Memory hotplug state changed, suspend refused.\n");
549 	return -EPERM;
550 }
551 
552 struct read_storage_sccb {
553 	struct sccb_header header;
554 	u16 max_id;
555 	u16 assigned;
556 	u16 standby;
557 	u16 :16;
558 	u32 entries[0];
559 } __packed;
560 
561 static const struct dev_pm_ops sclp_mem_pm_ops = {
562 	.freeze		= sclp_mem_freeze,
563 };
564 
565 static struct platform_driver sclp_mem_pdrv = {
566 	.driver = {
567 		.name	= "sclp_mem",
568 		.pm	= &sclp_mem_pm_ops,
569 	},
570 };
571 
572 static int __init sclp_detect_standby_memory(void)
573 {
574 	struct platform_device *sclp_pdev;
575 	struct read_storage_sccb *sccb;
576 	int i, id, assigned, rc;
577 
578 	if (!early_read_info_sccb_valid)
579 		return 0;
580 	if ((sclp_facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
581 		return 0;
582 	rc = -ENOMEM;
583 	sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
584 	if (!sccb)
585 		goto out;
586 	assigned = 0;
587 	for (id = 0; id <= sclp_max_storage_id; id++) {
588 		memset(sccb, 0, PAGE_SIZE);
589 		sccb->header.length = PAGE_SIZE;
590 		rc = do_sync_request(0x00040001 | id << 8, sccb);
591 		if (rc)
592 			goto out;
593 		switch (sccb->header.response_code) {
594 		case 0x0010:
595 			set_bit(id, sclp_storage_ids);
596 			for (i = 0; i < sccb->assigned; i++) {
597 				if (!sccb->entries[i])
598 					continue;
599 				assigned++;
600 				insert_increment(sccb->entries[i] >> 16, 0, 1);
601 			}
602 			break;
603 		case 0x0310:
604 			break;
605 		case 0x0410:
606 			for (i = 0; i < sccb->assigned; i++) {
607 				if (!sccb->entries[i])
608 					continue;
609 				assigned++;
610 				insert_increment(sccb->entries[i] >> 16, 1, 1);
611 			}
612 			break;
613 		default:
614 			rc = -EIO;
615 			break;
616 		}
617 		if (!rc)
618 			sclp_max_storage_id = sccb->max_id;
619 	}
620 	if (rc || list_empty(&sclp_mem_list))
621 		goto out;
622 	for (i = 1; i <= rnmax - assigned; i++)
623 		insert_increment(0, 1, 0);
624 	rc = register_memory_notifier(&sclp_mem_nb);
625 	if (rc)
626 		goto out;
627 	rc = platform_driver_register(&sclp_mem_pdrv);
628 	if (rc)
629 		goto out;
630 	sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0);
631 	rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0;
632 	if (rc)
633 		goto out_driver;
634 	sclp_add_standby_memory();
635 	goto out;
636 out_driver:
637 	platform_driver_unregister(&sclp_mem_pdrv);
638 out:
639 	free_page((unsigned long) sccb);
640 	return rc;
641 }
642 __initcall(sclp_detect_standby_memory);
643 
644 #endif /* CONFIG_MEMORY_HOTPLUG */
645 
646 /*
647  * Channel path configuration related functions.
648  */
649 
650 #define SCLP_CMDW_CONFIGURE_CHPATH		0x000f0001
651 #define SCLP_CMDW_DECONFIGURE_CHPATH		0x000e0001
652 #define SCLP_CMDW_READ_CHPATH_INFORMATION	0x00030001
653 
654 struct chp_cfg_sccb {
655 	struct sccb_header header;
656 	u8 ccm;
657 	u8 reserved[6];
658 	u8 cssid;
659 } __attribute__((packed));
660 
661 static int do_chp_configure(sclp_cmdw_t cmd)
662 {
663 	struct chp_cfg_sccb *sccb;
664 	int rc;
665 
666 	if (!SCLP_HAS_CHP_RECONFIG)
667 		return -EOPNOTSUPP;
668 	/* Prepare sccb. */
669 	sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
670 	if (!sccb)
671 		return -ENOMEM;
672 	sccb->header.length = sizeof(*sccb);
673 	rc = do_sync_request(cmd, sccb);
674 	if (rc)
675 		goto out;
676 	switch (sccb->header.response_code) {
677 	case 0x0020:
678 	case 0x0120:
679 	case 0x0440:
680 	case 0x0450:
681 		break;
682 	default:
683 		pr_warning("configure channel-path failed "
684 			   "(cmd=0x%08x, response=0x%04x)\n", cmd,
685 			   sccb->header.response_code);
686 		rc = -EIO;
687 		break;
688 	}
689 out:
690 	free_page((unsigned long) sccb);
691 	return rc;
692 }
693 
694 /**
695  * sclp_chp_configure - perform configure channel-path sclp command
696  * @chpid: channel-path ID
697  *
698  * Perform configure channel-path command sclp command for specified chpid.
699  * Return 0 after command successfully finished, non-zero otherwise.
700  */
701 int sclp_chp_configure(struct chp_id chpid)
702 {
703 	return do_chp_configure(SCLP_CMDW_CONFIGURE_CHPATH | chpid.id << 8);
704 }
705 
706 /**
707  * sclp_chp_deconfigure - perform deconfigure channel-path sclp command
708  * @chpid: channel-path ID
709  *
710  * Perform deconfigure channel-path command sclp command for specified chpid
711  * and wait for completion. On success return 0. Return non-zero otherwise.
712  */
713 int sclp_chp_deconfigure(struct chp_id chpid)
714 {
715 	return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8);
716 }
717 
718 struct chp_info_sccb {
719 	struct sccb_header header;
720 	u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
721 	u8 standby[SCLP_CHP_INFO_MASK_SIZE];
722 	u8 configured[SCLP_CHP_INFO_MASK_SIZE];
723 	u8 ccm;
724 	u8 reserved[6];
725 	u8 cssid;
726 } __attribute__((packed));
727 
728 /**
729  * sclp_chp_read_info - perform read channel-path information sclp command
730  * @info: resulting channel-path information data
731  *
732  * Perform read channel-path information sclp command and wait for completion.
733  * On success, store channel-path information in @info and return 0. Return
734  * non-zero otherwise.
735  */
736 int sclp_chp_read_info(struct sclp_chp_info *info)
737 {
738 	struct chp_info_sccb *sccb;
739 	int rc;
740 
741 	if (!SCLP_HAS_CHP_INFO)
742 		return -EOPNOTSUPP;
743 	/* Prepare sccb. */
744 	sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
745 	if (!sccb)
746 		return -ENOMEM;
747 	sccb->header.length = sizeof(*sccb);
748 	rc = do_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
749 	if (rc)
750 		goto out;
751 	if (sccb->header.response_code != 0x0010) {
752 		pr_warning("read channel-path info failed "
753 			   "(response=0x%04x)\n", sccb->header.response_code);
754 		rc = -EIO;
755 		goto out;
756 	}
757 	memcpy(info->recognized, sccb->recognized, SCLP_CHP_INFO_MASK_SIZE);
758 	memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE);
759 	memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE);
760 out:
761 	free_page((unsigned long) sccb);
762 	return rc;
763 }
764