[S390] pm: memory hotplug power management callbacks
[linux-2.6] / drivers / s390 / char / sclp_cmd.c
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 }