xref: /linux/drivers/s390/char/sclp_cmd.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright IBM Corp. 2007,2012
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/export.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/mm.h>
19 #include <linux/mmzone.h>
20 #include <linux/memory.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <asm/ctl_reg.h>
24 #include <asm/chpid.h>
25 #include <asm/setup.h>
26 #include <asm/page.h>
27 #include <asm/sclp.h>
28 #include <asm/numa.h>
29 
30 #include "sclp.h"
31 
32 static void sclp_sync_callback(struct sclp_req *req, void *data)
33 {
34 	struct completion *completion = data;
35 
36 	complete(completion);
37 }
38 
39 int sclp_sync_request(sclp_cmdw_t cmd, void *sccb)
40 {
41 	return sclp_sync_request_timeout(cmd, sccb, 0);
42 }
43 
44 int sclp_sync_request_timeout(sclp_cmdw_t cmd, void *sccb, int timeout)
45 {
46 	struct completion completion;
47 	struct sclp_req *request;
48 	int rc;
49 
50 	request = kzalloc(sizeof(*request), GFP_KERNEL);
51 	if (!request)
52 		return -ENOMEM;
53 	if (timeout)
54 		request->queue_timeout = timeout;
55 	request->command = cmd;
56 	request->sccb = sccb;
57 	request->status = SCLP_REQ_FILLED;
58 	request->callback = sclp_sync_callback;
59 	request->callback_data = &completion;
60 	init_completion(&completion);
61 
62 	/* Perform sclp request. */
63 	rc = sclp_add_request(request);
64 	if (rc)
65 		goto out;
66 	wait_for_completion(&completion);
67 
68 	/* Check response. */
69 	if (request->status != SCLP_REQ_DONE) {
70 		pr_warning("sync request failed (cmd=0x%08x, "
71 			   "status=0x%02x)\n", cmd, request->status);
72 		rc = -EIO;
73 	}
74 out:
75 	kfree(request);
76 	return rc;
77 }
78 
79 /*
80  * CPU configuration related functions.
81  */
82 
83 #define SCLP_CMDW_READ_CPU_INFO		0x00010001
84 #define SCLP_CMDW_CONFIGURE_CPU		0x00110001
85 #define SCLP_CMDW_DECONFIGURE_CPU	0x00100001
86 
87 struct read_cpu_info_sccb {
88 	struct	sccb_header header;
89 	u16	nr_configured;
90 	u16	offset_configured;
91 	u16	nr_standby;
92 	u16	offset_standby;
93 	u8	reserved[4096 - 16];
94 } __attribute__((packed, aligned(PAGE_SIZE)));
95 
96 static void sclp_fill_core_info(struct sclp_core_info *info,
97 				struct read_cpu_info_sccb *sccb)
98 {
99 	char *page = (char *) sccb;
100 
101 	memset(info, 0, sizeof(*info));
102 	info->configured = sccb->nr_configured;
103 	info->standby = sccb->nr_standby;
104 	info->combined = sccb->nr_configured + sccb->nr_standby;
105 	memcpy(&info->core, page + sccb->offset_configured,
106 	       info->combined * sizeof(struct sclp_core_entry));
107 }
108 
109 int sclp_get_core_info(struct sclp_core_info *info)
110 {
111 	int rc;
112 	struct read_cpu_info_sccb *sccb;
113 
114 	if (!SCLP_HAS_CPU_INFO)
115 		return -EOPNOTSUPP;
116 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
117 	if (!sccb)
118 		return -ENOMEM;
119 	sccb->header.length = sizeof(*sccb);
120 	rc = sclp_sync_request_timeout(SCLP_CMDW_READ_CPU_INFO, sccb,
121 				       SCLP_QUEUE_INTERVAL);
122 	if (rc)
123 		goto out;
124 	if (sccb->header.response_code != 0x0010) {
125 		pr_warning("readcpuinfo failed (response=0x%04x)\n",
126 			   sccb->header.response_code);
127 		rc = -EIO;
128 		goto out;
129 	}
130 	sclp_fill_core_info(info, sccb);
131 out:
132 	free_page((unsigned long) sccb);
133 	return rc;
134 }
135 
136 struct cpu_configure_sccb {
137 	struct sccb_header header;
138 } __attribute__((packed, aligned(8)));
139 
140 static int do_core_configure(sclp_cmdw_t cmd)
141 {
142 	struct cpu_configure_sccb *sccb;
143 	int rc;
144 
145 	if (!SCLP_HAS_CPU_RECONFIG)
146 		return -EOPNOTSUPP;
147 	/*
148 	 * This is not going to cross a page boundary since we force
149 	 * kmalloc to have a minimum alignment of 8 bytes on s390.
150 	 */
151 	sccb = kzalloc(sizeof(*sccb), GFP_KERNEL | GFP_DMA);
152 	if (!sccb)
153 		return -ENOMEM;
154 	sccb->header.length = sizeof(*sccb);
155 	rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL);
156 	if (rc)
157 		goto out;
158 	switch (sccb->header.response_code) {
159 	case 0x0020:
160 	case 0x0120:
161 		break;
162 	default:
163 		pr_warning("configure cpu failed (cmd=0x%08x, "
164 			   "response=0x%04x)\n", cmd,
165 			   sccb->header.response_code);
166 		rc = -EIO;
167 		break;
168 	}
169 out:
170 	kfree(sccb);
171 	return rc;
172 }
173 
174 int sclp_core_configure(u8 core)
175 {
176 	return do_core_configure(SCLP_CMDW_CONFIGURE_CPU | core << 8);
177 }
178 
179 int sclp_core_deconfigure(u8 core)
180 {
181 	return do_core_configure(SCLP_CMDW_DECONFIGURE_CPU | core << 8);
182 }
183 
184 #ifdef CONFIG_MEMORY_HOTPLUG
185 
186 static DEFINE_MUTEX(sclp_mem_mutex);
187 static LIST_HEAD(sclp_mem_list);
188 static u8 sclp_max_storage_id;
189 static DECLARE_BITMAP(sclp_storage_ids, 256);
190 static int sclp_mem_state_changed;
191 
192 struct memory_increment {
193 	struct list_head list;
194 	u16 rn;
195 	int standby;
196 };
197 
198 struct assign_storage_sccb {
199 	struct sccb_header header;
200 	u16 rn;
201 } __packed;
202 
203 int arch_get_memory_phys_device(unsigned long start_pfn)
204 {
205 	if (!sclp.rzm)
206 		return 0;
207 	return PFN_PHYS(start_pfn) >> ilog2(sclp.rzm);
208 }
209 
210 static unsigned long long rn2addr(u16 rn)
211 {
212 	return (unsigned long long) (rn - 1) * sclp.rzm;
213 }
214 
215 static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
216 {
217 	struct assign_storage_sccb *sccb;
218 	int rc;
219 
220 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
221 	if (!sccb)
222 		return -ENOMEM;
223 	sccb->header.length = PAGE_SIZE;
224 	sccb->rn = rn;
225 	rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL);
226 	if (rc)
227 		goto out;
228 	switch (sccb->header.response_code) {
229 	case 0x0020:
230 	case 0x0120:
231 		break;
232 	default:
233 		pr_warning("assign storage failed (cmd=0x%08x, "
234 			   "response=0x%04x, rn=0x%04x)\n", cmd,
235 			   sccb->header.response_code, rn);
236 		rc = -EIO;
237 		break;
238 	}
239 out:
240 	free_page((unsigned long) sccb);
241 	return rc;
242 }
243 
244 static int sclp_assign_storage(u16 rn)
245 {
246 	unsigned long long start;
247 	int rc;
248 
249 	rc = do_assign_storage(0x000d0001, rn);
250 	if (rc)
251 		return rc;
252 	start = rn2addr(rn);
253 	storage_key_init_range(start, start + sclp.rzm);
254 	return 0;
255 }
256 
257 static int sclp_unassign_storage(u16 rn)
258 {
259 	return do_assign_storage(0x000c0001, rn);
260 }
261 
262 struct attach_storage_sccb {
263 	struct sccb_header header;
264 	u16 :16;
265 	u16 assigned;
266 	u32 :32;
267 	u32 entries[0];
268 } __packed;
269 
270 static int sclp_attach_storage(u8 id)
271 {
272 	struct attach_storage_sccb *sccb;
273 	int rc;
274 	int i;
275 
276 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
277 	if (!sccb)
278 		return -ENOMEM;
279 	sccb->header.length = PAGE_SIZE;
280 	rc = sclp_sync_request_timeout(0x00080001 | id << 8, sccb,
281 				       SCLP_QUEUE_INTERVAL);
282 	if (rc)
283 		goto out;
284 	switch (sccb->header.response_code) {
285 	case 0x0020:
286 		set_bit(id, sclp_storage_ids);
287 		for (i = 0; i < sccb->assigned; i++) {
288 			if (sccb->entries[i])
289 				sclp_unassign_storage(sccb->entries[i] >> 16);
290 		}
291 		break;
292 	default:
293 		rc = -EIO;
294 		break;
295 	}
296 out:
297 	free_page((unsigned long) sccb);
298 	return rc;
299 }
300 
301 static int sclp_mem_change_state(unsigned long start, unsigned long size,
302 				 int online)
303 {
304 	struct memory_increment *incr;
305 	unsigned long long istart;
306 	int rc = 0;
307 
308 	list_for_each_entry(incr, &sclp_mem_list, list) {
309 		istart = rn2addr(incr->rn);
310 		if (start + size - 1 < istart)
311 			break;
312 		if (start > istart + sclp.rzm - 1)
313 			continue;
314 		if (online)
315 			rc |= sclp_assign_storage(incr->rn);
316 		else
317 			sclp_unassign_storage(incr->rn);
318 		if (rc == 0)
319 			incr->standby = online ? 0 : 1;
320 	}
321 	return rc ? -EIO : 0;
322 }
323 
324 static bool contains_standby_increment(unsigned long start, unsigned long end)
325 {
326 	struct memory_increment *incr;
327 	unsigned long istart;
328 
329 	list_for_each_entry(incr, &sclp_mem_list, list) {
330 		istart = rn2addr(incr->rn);
331 		if (end - 1 < istart)
332 			continue;
333 		if (start > istart + sclp.rzm - 1)
334 			continue;
335 		if (incr->standby)
336 			return true;
337 	}
338 	return false;
339 }
340 
341 static int sclp_mem_notifier(struct notifier_block *nb,
342 			     unsigned long action, void *data)
343 {
344 	unsigned long start, size;
345 	struct memory_notify *arg;
346 	unsigned char id;
347 	int rc = 0;
348 
349 	arg = data;
350 	start = arg->start_pfn << PAGE_SHIFT;
351 	size = arg->nr_pages << PAGE_SHIFT;
352 	mutex_lock(&sclp_mem_mutex);
353 	for_each_clear_bit(id, sclp_storage_ids, sclp_max_storage_id + 1)
354 		sclp_attach_storage(id);
355 	switch (action) {
356 	case MEM_GOING_OFFLINE:
357 		/*
358 		 * We do not allow to set memory blocks offline that contain
359 		 * standby memory. This is done to simplify the "memory online"
360 		 * case.
361 		 */
362 		if (contains_standby_increment(start, start + size))
363 			rc = -EPERM;
364 		break;
365 	case MEM_ONLINE:
366 	case MEM_CANCEL_OFFLINE:
367 		break;
368 	case MEM_GOING_ONLINE:
369 		rc = sclp_mem_change_state(start, size, 1);
370 		break;
371 	case MEM_CANCEL_ONLINE:
372 		sclp_mem_change_state(start, size, 0);
373 		break;
374 	case MEM_OFFLINE:
375 		sclp_mem_change_state(start, size, 0);
376 		break;
377 	default:
378 		rc = -EINVAL;
379 		break;
380 	}
381 	if (!rc)
382 		sclp_mem_state_changed = 1;
383 	mutex_unlock(&sclp_mem_mutex);
384 	return rc ? NOTIFY_BAD : NOTIFY_OK;
385 }
386 
387 static struct notifier_block sclp_mem_nb = {
388 	.notifier_call = sclp_mem_notifier,
389 };
390 
391 static void __init align_to_block_size(unsigned long long *start,
392 				       unsigned long long *size,
393 				       unsigned long long alignment)
394 {
395 	unsigned long long start_align, size_align;
396 
397 	start_align = roundup(*start, alignment);
398 	size_align = rounddown(*start + *size, alignment) - start_align;
399 
400 	pr_info("Standby memory at 0x%llx (%lluM of %lluM usable)\n",
401 		*start, size_align >> 20, *size >> 20);
402 	*start = start_align;
403 	*size = size_align;
404 }
405 
406 static void __init add_memory_merged(u16 rn)
407 {
408 	unsigned long long start, size, addr, block_size;
409 	static u16 first_rn, num;
410 
411 	if (rn && first_rn && (first_rn + num == rn)) {
412 		num++;
413 		return;
414 	}
415 	if (!first_rn)
416 		goto skip_add;
417 	start = rn2addr(first_rn);
418 	size = (unsigned long long) num * sclp.rzm;
419 	if (start >= VMEM_MAX_PHYS)
420 		goto skip_add;
421 	if (start + size > VMEM_MAX_PHYS)
422 		size = VMEM_MAX_PHYS - start;
423 	if (memory_end_set && (start >= memory_end))
424 		goto skip_add;
425 	if (memory_end_set && (start + size > memory_end))
426 		size = memory_end - start;
427 	block_size = memory_block_size_bytes();
428 	align_to_block_size(&start, &size, block_size);
429 	if (!size)
430 		goto skip_add;
431 	for (addr = start; addr < start + size; addr += block_size)
432 		add_memory(numa_pfn_to_nid(PFN_DOWN(addr)), addr, block_size);
433 skip_add:
434 	first_rn = rn;
435 	num = 1;
436 }
437 
438 static void __init sclp_add_standby_memory(void)
439 {
440 	struct memory_increment *incr;
441 
442 	list_for_each_entry(incr, &sclp_mem_list, list)
443 		if (incr->standby)
444 			add_memory_merged(incr->rn);
445 	add_memory_merged(0);
446 }
447 
448 static void __init insert_increment(u16 rn, int standby, int assigned)
449 {
450 	struct memory_increment *incr, *new_incr;
451 	struct list_head *prev;
452 	u16 last_rn;
453 
454 	new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
455 	if (!new_incr)
456 		return;
457 	new_incr->rn = rn;
458 	new_incr->standby = standby;
459 	last_rn = 0;
460 	prev = &sclp_mem_list;
461 	list_for_each_entry(incr, &sclp_mem_list, list) {
462 		if (assigned && incr->rn > rn)
463 			break;
464 		if (!assigned && incr->rn - last_rn > 1)
465 			break;
466 		last_rn = incr->rn;
467 		prev = &incr->list;
468 	}
469 	if (!assigned)
470 		new_incr->rn = last_rn + 1;
471 	if (new_incr->rn > sclp.rnmax) {
472 		kfree(new_incr);
473 		return;
474 	}
475 	list_add(&new_incr->list, prev);
476 }
477 
478 static int sclp_mem_freeze(struct device *dev)
479 {
480 	if (!sclp_mem_state_changed)
481 		return 0;
482 	pr_err("Memory hotplug state changed, suspend refused.\n");
483 	return -EPERM;
484 }
485 
486 struct read_storage_sccb {
487 	struct sccb_header header;
488 	u16 max_id;
489 	u16 assigned;
490 	u16 standby;
491 	u16 :16;
492 	u32 entries[0];
493 } __packed;
494 
495 static const struct dev_pm_ops sclp_mem_pm_ops = {
496 	.freeze		= sclp_mem_freeze,
497 };
498 
499 static struct platform_driver sclp_mem_pdrv = {
500 	.driver = {
501 		.name	= "sclp_mem",
502 		.pm	= &sclp_mem_pm_ops,
503 	},
504 };
505 
506 static int __init sclp_detect_standby_memory(void)
507 {
508 	struct platform_device *sclp_pdev;
509 	struct read_storage_sccb *sccb;
510 	int i, id, assigned, rc;
511 
512 	if (OLDMEM_BASE) /* No standby memory in kdump mode */
513 		return 0;
514 	if ((sclp.facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
515 		return 0;
516 	rc = -ENOMEM;
517 	sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
518 	if (!sccb)
519 		goto out;
520 	assigned = 0;
521 	for (id = 0; id <= sclp_max_storage_id; id++) {
522 		memset(sccb, 0, PAGE_SIZE);
523 		sccb->header.length = PAGE_SIZE;
524 		rc = sclp_sync_request(0x00040001 | id << 8, sccb);
525 		if (rc)
526 			goto out;
527 		switch (sccb->header.response_code) {
528 		case 0x0010:
529 			set_bit(id, sclp_storage_ids);
530 			for (i = 0; i < sccb->assigned; i++) {
531 				if (!sccb->entries[i])
532 					continue;
533 				assigned++;
534 				insert_increment(sccb->entries[i] >> 16, 0, 1);
535 			}
536 			break;
537 		case 0x0310:
538 			break;
539 		case 0x0410:
540 			for (i = 0; i < sccb->assigned; i++) {
541 				if (!sccb->entries[i])
542 					continue;
543 				assigned++;
544 				insert_increment(sccb->entries[i] >> 16, 1, 1);
545 			}
546 			break;
547 		default:
548 			rc = -EIO;
549 			break;
550 		}
551 		if (!rc)
552 			sclp_max_storage_id = sccb->max_id;
553 	}
554 	if (rc || list_empty(&sclp_mem_list))
555 		goto out;
556 	for (i = 1; i <= sclp.rnmax - assigned; i++)
557 		insert_increment(0, 1, 0);
558 	rc = register_memory_notifier(&sclp_mem_nb);
559 	if (rc)
560 		goto out;
561 	rc = platform_driver_register(&sclp_mem_pdrv);
562 	if (rc)
563 		goto out;
564 	sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0);
565 	rc = PTR_ERR_OR_ZERO(sclp_pdev);
566 	if (rc)
567 		goto out_driver;
568 	sclp_add_standby_memory();
569 	goto out;
570 out_driver:
571 	platform_driver_unregister(&sclp_mem_pdrv);
572 out:
573 	free_page((unsigned long) sccb);
574 	return rc;
575 }
576 __initcall(sclp_detect_standby_memory);
577 
578 #endif /* CONFIG_MEMORY_HOTPLUG */
579 
580 /*
581  * PCI I/O adapter configuration related functions.
582  */
583 #define SCLP_CMDW_CONFIGURE_PCI			0x001a0001
584 #define SCLP_CMDW_DECONFIGURE_PCI		0x001b0001
585 
586 #define SCLP_RECONFIG_PCI_ATPYE			2
587 
588 struct pci_cfg_sccb {
589 	struct sccb_header header;
590 	u8 atype;		/* adapter type */
591 	u8 reserved1;
592 	u16 reserved2;
593 	u32 aid;		/* adapter identifier */
594 } __packed;
595 
596 static int do_pci_configure(sclp_cmdw_t cmd, u32 fid)
597 {
598 	struct pci_cfg_sccb *sccb;
599 	int rc;
600 
601 	if (!SCLP_HAS_PCI_RECONFIG)
602 		return -EOPNOTSUPP;
603 
604 	sccb = (struct pci_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
605 	if (!sccb)
606 		return -ENOMEM;
607 
608 	sccb->header.length = PAGE_SIZE;
609 	sccb->atype = SCLP_RECONFIG_PCI_ATPYE;
610 	sccb->aid = fid;
611 	rc = sclp_sync_request(cmd, sccb);
612 	if (rc)
613 		goto out;
614 	switch (sccb->header.response_code) {
615 	case 0x0020:
616 	case 0x0120:
617 		break;
618 	default:
619 		pr_warn("configure PCI I/O adapter failed: cmd=0x%08x  response=0x%04x\n",
620 			cmd, sccb->header.response_code);
621 		rc = -EIO;
622 		break;
623 	}
624 out:
625 	free_page((unsigned long) sccb);
626 	return rc;
627 }
628 
629 int sclp_pci_configure(u32 fid)
630 {
631 	return do_pci_configure(SCLP_CMDW_CONFIGURE_PCI, fid);
632 }
633 EXPORT_SYMBOL(sclp_pci_configure);
634 
635 int sclp_pci_deconfigure(u32 fid)
636 {
637 	return do_pci_configure(SCLP_CMDW_DECONFIGURE_PCI, fid);
638 }
639 EXPORT_SYMBOL(sclp_pci_deconfigure);
640 
641 /*
642  * Channel path configuration related functions.
643  */
644 
645 #define SCLP_CMDW_CONFIGURE_CHPATH		0x000f0001
646 #define SCLP_CMDW_DECONFIGURE_CHPATH		0x000e0001
647 #define SCLP_CMDW_READ_CHPATH_INFORMATION	0x00030001
648 
649 struct chp_cfg_sccb {
650 	struct sccb_header header;
651 	u8 ccm;
652 	u8 reserved[6];
653 	u8 cssid;
654 } __attribute__((packed));
655 
656 static int do_chp_configure(sclp_cmdw_t cmd)
657 {
658 	struct chp_cfg_sccb *sccb;
659 	int rc;
660 
661 	if (!SCLP_HAS_CHP_RECONFIG)
662 		return -EOPNOTSUPP;
663 	/* Prepare sccb. */
664 	sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
665 	if (!sccb)
666 		return -ENOMEM;
667 	sccb->header.length = sizeof(*sccb);
668 	rc = sclp_sync_request(cmd, sccb);
669 	if (rc)
670 		goto out;
671 	switch (sccb->header.response_code) {
672 	case 0x0020:
673 	case 0x0120:
674 	case 0x0440:
675 	case 0x0450:
676 		break;
677 	default:
678 		pr_warning("configure channel-path failed "
679 			   "(cmd=0x%08x, response=0x%04x)\n", cmd,
680 			   sccb->header.response_code);
681 		rc = -EIO;
682 		break;
683 	}
684 out:
685 	free_page((unsigned long) sccb);
686 	return rc;
687 }
688 
689 /**
690  * sclp_chp_configure - perform configure channel-path sclp command
691  * @chpid: channel-path ID
692  *
693  * Perform configure channel-path command sclp command for specified chpid.
694  * Return 0 after command successfully finished, non-zero otherwise.
695  */
696 int sclp_chp_configure(struct chp_id chpid)
697 {
698 	return do_chp_configure(SCLP_CMDW_CONFIGURE_CHPATH | chpid.id << 8);
699 }
700 
701 /**
702  * sclp_chp_deconfigure - perform deconfigure channel-path sclp command
703  * @chpid: channel-path ID
704  *
705  * Perform deconfigure channel-path command sclp command for specified chpid
706  * and wait for completion. On success return 0. Return non-zero otherwise.
707  */
708 int sclp_chp_deconfigure(struct chp_id chpid)
709 {
710 	return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8);
711 }
712 
713 struct chp_info_sccb {
714 	struct sccb_header header;
715 	u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
716 	u8 standby[SCLP_CHP_INFO_MASK_SIZE];
717 	u8 configured[SCLP_CHP_INFO_MASK_SIZE];
718 	u8 ccm;
719 	u8 reserved[6];
720 	u8 cssid;
721 } __attribute__((packed));
722 
723 /**
724  * sclp_chp_read_info - perform read channel-path information sclp command
725  * @info: resulting channel-path information data
726  *
727  * Perform read channel-path information sclp command and wait for completion.
728  * On success, store channel-path information in @info and return 0. Return
729  * non-zero otherwise.
730  */
731 int sclp_chp_read_info(struct sclp_chp_info *info)
732 {
733 	struct chp_info_sccb *sccb;
734 	int rc;
735 
736 	if (!SCLP_HAS_CHP_INFO)
737 		return -EOPNOTSUPP;
738 	/* Prepare sccb. */
739 	sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
740 	if (!sccb)
741 		return -ENOMEM;
742 	sccb->header.length = sizeof(*sccb);
743 	rc = sclp_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
744 	if (rc)
745 		goto out;
746 	if (sccb->header.response_code != 0x0010) {
747 		pr_warning("read channel-path info failed "
748 			   "(response=0x%04x)\n", sccb->header.response_code);
749 		rc = -EIO;
750 		goto out;
751 	}
752 	memcpy(info->recognized, sccb->recognized, SCLP_CHP_INFO_MASK_SIZE);
753 	memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE);
754 	memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE);
755 out:
756 	free_page((unsigned long) sccb);
757 	return rc;
758 }
759