[S390] cleanup psw related bits and pieces
[linux-2.6.git] / 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_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 }