drivers/s390/char/sclp_cmd.c

   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
  29 #include "sclp.h"
  30
  31 static void sclp_sync_callback(struct sclp_req *req, void *data)
  32 {
  33         struct completion *completion = data;
  34
  35         complete(completion);
  36 }
  37
  38 int sclp_sync_request(sclp_cmdw_t cmd, void *sccb)
  39 {
  40         return sclp_sync_request_timeout(cmd, sccb, 0);
  41 }
  42
  43 int sclp_sync_request_timeout(sclp_cmdw_t cmd, void *sccb, int timeout)
  44 {
  45         struct completion completion;
  46         struct sclp_req *request;
  47         int rc;
  48
  49         request = kzalloc(sizeof(*request), GFP_KERNEL);
  50         if (!request)
  51                 return -ENOMEM;
  52         if (timeout)
  53                 request->queue_timeout = timeout;
  54         request->command = cmd;
  55         request->sccb = sccb;
  56         request->status = SCLP_REQ_FILLED;
  57         request->callback = sclp_sync_callback;
  58         request->callback_data = &completion;
  59         init_completion(&completion);
  60
  61         /* Perform sclp request. */
  62         rc = sclp_add_request(request);
  63         if (rc)
  64                 goto out;
  65         wait_for_completion(&completion);
  66
  67         /* Check response. */
  68         if (request->status != SCLP_REQ_DONE) {
  69                 pr_warning("sync request failed (cmd=0x%08x, "
  70                            "status=0x%02x)\n", cmd, request->status);
  71                 rc = -EIO;
  72         }
  73 out:
  74         kfree(request);
  75         return rc;
  76 }
  77
  78 /*
  79  * CPU configuration related functions.
  80  */
  81
  82 #define SCLP_CMDW_READ_CPU_INFO         0x00010001
  83 #define SCLP_CMDW_CONFIGURE_CPU         0x00110001
  84 #define SCLP_CMDW_DECONFIGURE_CPU       0x00100001
  85
  86 struct read_cpu_info_sccb {
  87         struct  sccb_header header;
  88         u16     nr_configured;
  89         u16     offset_configured;
  90         u16     nr_standby;
  91         u16     offset_standby;
  92         u8      reserved[4096 - 16];
  93 } __attribute__((packed, aligned(PAGE_SIZE)));
  94
  95 static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
  96                                struct read_cpu_info_sccb *sccb)
  97 {
  98         char *page = (char *) sccb;
  99
 100         memset(info, 0, sizeof(*info));
 101         info->configured = sccb->nr_configured;
 102         info->standby = sccb->nr_standby;
 103         info->combined = sccb->nr_configured + sccb->nr_standby;
 104         info->has_cpu_type = sclp_fac84 & 0x1;
 105         memcpy(&info->cpu, page + sccb->offset_configured,
 106                info->combined * sizeof(struct sclp_cpu_entry));
 107 }
 108
 109 int sclp_get_cpu_info(struct sclp_cpu_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_cpu_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_cpu_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_cpu_configure(u8 cpu)
 175 {
 176         return do_cpu_configure(SCLP_CMDW_CONFIGURE_CPU | cpu << 8);
 177 }
 178
 179 int sclp_cpu_deconfigure(u8 cpu)
 180 {
 181         return do_cpu_configure(SCLP_CMDW_DECONFIGURE_CPU | cpu << 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 unsigned long sclp_storage_ids[256 / BITS_PER_LONG];
 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         }
 319         return rc ? -EIO : 0;
 320 }
 321
 322 static int sclp_mem_notifier(struct notifier_block *nb,
 323                              unsigned long action, void *data)
 324 {
 325         unsigned long start, size;
 326         struct memory_notify *arg;
 327         unsigned char id;
 328         int rc = 0;
 329
 330         arg = data;
 331         start = arg->start_pfn << PAGE_SHIFT;
 332         size = arg->nr_pages << PAGE_SHIFT;
 333         mutex_lock(&sclp_mem_mutex);
 334         for_each_clear_bit(id, sclp_storage_ids, sclp_max_storage_id + 1)
 335                 sclp_attach_storage(id);
 336         switch (action) {
 337         case MEM_ONLINE:
 338         case MEM_GOING_OFFLINE:
 339         case MEM_CANCEL_OFFLINE:
 340                 break;
 341         case MEM_GOING_ONLINE:
 342                 rc = sclp_mem_change_state(start, size, 1);
 343                 break;
 344         case MEM_CANCEL_ONLINE:
 345                 sclp_mem_change_state(start, size, 0);
 346                 break;
 347         case MEM_OFFLINE:
 348                 sclp_mem_change_state(start, size, 0);
 349                 break;
 350         default:
 351                 rc = -EINVAL;
 352                 break;
 353         }
 354         if (!rc)
 355                 sclp_mem_state_changed = 1;
 356         mutex_unlock(&sclp_mem_mutex);
 357         return rc ? NOTIFY_BAD : NOTIFY_OK;
 358 }
 359
 360 static struct notifier_block sclp_mem_nb = {
 361         .notifier_call = sclp_mem_notifier,
 362 };
 363
 364 static void __init add_memory_merged(u16 rn)
 365 {
 366         static u16 first_rn, num;
 367         unsigned long long start, size;
 368
 369         if (rn && first_rn && (first_rn + num == rn)) {
 370                 num++;
 371                 return;
 372         }
 373         if (!first_rn)
 374                 goto skip_add;
 375         start = rn2addr(first_rn);
 376         size = (unsigned long long) num * sclp_rzm;
 377         if (start >= VMEM_MAX_PHYS)
 378                 goto skip_add;
 379         if (start + size > VMEM_MAX_PHYS)
 380                 size = VMEM_MAX_PHYS - start;
 381         if (memory_end_set && (start >= memory_end))
 382                 goto skip_add;
 383         if (memory_end_set && (start + size > memory_end))
 384                 size = memory_end - start;
 385         add_memory(0, start, size);
 386 skip_add:
 387         first_rn = rn;
 388         num = 1;
 389 }
 390
 391 static void __init sclp_add_standby_memory(void)
 392 {
 393         struct memory_increment *incr;
 394
 395         list_for_each_entry(incr, &sclp_mem_list, list)
 396                 if (incr->standby)
 397                         add_memory_merged(incr->rn);
 398         add_memory_merged(0);
 399 }
 400
 401 static void __init insert_increment(u16 rn, int standby, int assigned)
 402 {
 403         struct memory_increment *incr, *new_incr;
 404         struct list_head *prev;
 405         u16 last_rn;
 406
 407         new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
 408         if (!new_incr)
 409                 return;
 410         new_incr->rn = rn;
 411         new_incr->standby = standby;
 412         last_rn = 0;
 413         prev = &sclp_mem_list;
 414         list_for_each_entry(incr, &sclp_mem_list, list) {
 415                 if (assigned && incr->rn > rn)
 416                         break;
 417                 if (!assigned && incr->rn - last_rn > 1)
 418                         break;
 419                 last_rn = incr->rn;
 420                 prev = &incr->list;
 421         }
 422         if (!assigned)
 423                 new_incr->rn = last_rn + 1;
 424         if (new_incr->rn > sclp_rnmax) {
 425                 kfree(new_incr);
 426                 return;
 427         }
 428         list_add(&new_incr->list, prev);
 429 }
 430
 431 static int sclp_mem_freeze(struct device *dev)
 432 {
 433         if (!sclp_mem_state_changed)
 434                 return 0;
 435         pr_err("Memory hotplug state changed, suspend refused.\n");
 436         return -EPERM;
 437 }
 438
 439 struct read_storage_sccb {
 440         struct sccb_header header;
 441         u16 max_id;
 442         u16 assigned;
 443         u16 standby;
 444         u16 :16;
 445         u32 entries[0];
 446 } __packed;
 447
 448 static const struct dev_pm_ops sclp_mem_pm_ops = {
 449         .freeze         = sclp_mem_freeze,
 450 };
 451
 452 static struct platform_driver sclp_mem_pdrv = {
 453         .driver = {
 454                 .name   = "sclp_mem",
 455                 .pm     = &sclp_mem_pm_ops,
 456         },
 457 };
 458
 459 static int __init sclp_detect_standby_memory(void)
 460 {
 461         struct platform_device *sclp_pdev;
 462         struct read_storage_sccb *sccb;
 463         int i, id, assigned, rc;
 464
 465         if (OLDMEM_BASE) /* No standby memory in kdump mode */
 466                 return 0;
 467         if ((sclp_facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
 468                 return 0;
 469         rc = -ENOMEM;
 470         sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
 471         if (!sccb)
 472                 goto out;
 473         assigned = 0;
 474         for (id = 0; id <= sclp_max_storage_id; id++) {
 475                 memset(sccb, 0, PAGE_SIZE);
 476                 sccb->header.length = PAGE_SIZE;
 477                 rc = sclp_sync_request(0x00040001 | id << 8, sccb);
 478                 if (rc)
 479                         goto out;
 480                 switch (sccb->header.response_code) {
 481                 case 0x0010:
 482                         set_bit(id, sclp_storage_ids);
 483                         for (i = 0; i < sccb->assigned; i++) {
 484                                 if (!sccb->entries[i])
 485                                         continue;
 486                                 assigned++;
 487                                 insert_increment(sccb->entries[i] >> 16, 0, 1);
 488                         }
 489                         break;
 490                 case 0x0310:
 491                         break;
 492                 case 0x0410:
 493                         for (i = 0; i < sccb->assigned; i++) {
 494                                 if (!sccb->entries[i])
 495                                         continue;
 496                                 assigned++;
 497                                 insert_increment(sccb->entries[i] >> 16, 1, 1);
 498                         }
 499                         break;
 500                 default:
 501                         rc = -EIO;
 502                         break;
 503                 }
 504                 if (!rc)
 505                         sclp_max_storage_id = sccb->max_id;
 506         }
 507         if (rc || list_empty(&sclp_mem_list))
 508                 goto out;
 509         for (i = 1; i <= sclp_rnmax - assigned; i++)
 510                 insert_increment(0, 1, 0);
 511         rc = register_memory_notifier(&sclp_mem_nb);
 512         if (rc)
 513                 goto out;
 514         rc = platform_driver_register(&sclp_mem_pdrv);
 515         if (rc)
 516                 goto out;
 517         sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0);
 518         rc = PTR_RET(sclp_pdev);
 519         if (rc)
 520                 goto out_driver;
 521         sclp_add_standby_memory();
 522         goto out;
 523 out_driver:
 524         platform_driver_unregister(&sclp_mem_pdrv);
 525 out:
 526         free_page((unsigned long) sccb);
 527         return rc;
 528 }
 529 __initcall(sclp_detect_standby_memory);
 530
 531 #endif /* CONFIG_MEMORY_HOTPLUG */
 532
 533 /*
 534  * PCI I/O adapter configuration related functions.
 535  */
 536 #define SCLP_CMDW_CONFIGURE_PCI                 0x001a0001
 537 #define SCLP_CMDW_DECONFIGURE_PCI               0x001b0001
 538
 539 #define SCLP_RECONFIG_PCI_ATPYE                 2
 540
 541 struct pci_cfg_sccb {
 542         struct sccb_header header;
 543         u8 atype;               /* adapter type */
 544         u8 reserved1;
 545         u16 reserved2;
 546         u32 aid;                /* adapter identifier */
 547 } __packed;
 548
 549 static int do_pci_configure(sclp_cmdw_t cmd, u32 fid)
 550 {
 551         struct pci_cfg_sccb *sccb;
 552         int rc;
 553
 554         if (!SCLP_HAS_PCI_RECONFIG)
 555                 return -EOPNOTSUPP;
 556
 557         sccb = (struct pci_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 558         if (!sccb)
 559                 return -ENOMEM;
 560
 561         sccb->header.length = PAGE_SIZE;
 562         sccb->atype = SCLP_RECONFIG_PCI_ATPYE;
 563         sccb->aid = fid;
 564         rc = sclp_sync_request(cmd, sccb);
 565         if (rc)
 566                 goto out;
 567         switch (sccb->header.response_code) {
 568         case 0x0020:
 569         case 0x0120:
 570                 break;
 571         default:
 572                 pr_warn("configure PCI I/O adapter failed: cmd=0x%08x  response=0x%04x\n",
 573                         cmd, sccb->header.response_code);
 574                 rc = -EIO;
 575                 break;
 576         }
 577 out:
 578         free_page((unsigned long) sccb);
 579         return rc;
 580 }
 581
 582 int sclp_pci_configure(u32 fid)
 583 {
 584         return do_pci_configure(SCLP_CMDW_CONFIGURE_PCI, fid);
 585 }
 586 EXPORT_SYMBOL(sclp_pci_configure);
 587
 588 int sclp_pci_deconfigure(u32 fid)
 589 {
 590         return do_pci_configure(SCLP_CMDW_DECONFIGURE_PCI, fid);
 591 }
 592 EXPORT_SYMBOL(sclp_pci_deconfigure);
 593
 594 /*
 595  * Channel path configuration related functions.
 596  */
 597
 598 #define SCLP_CMDW_CONFIGURE_CHPATH              0x000f0001
 599 #define SCLP_CMDW_DECONFIGURE_CHPATH            0x000e0001
 600 #define SCLP_CMDW_READ_CHPATH_INFORMATION       0x00030001
 601
 602 struct chp_cfg_sccb {
 603         struct sccb_header header;
 604         u8 ccm;
 605         u8 reserved[6];
 606         u8 cssid;
 607 } __attribute__((packed));
 608
 609 static int do_chp_configure(sclp_cmdw_t cmd)
 610 {
 611         struct chp_cfg_sccb *sccb;
 612         int rc;
 613
 614         if (!SCLP_HAS_CHP_RECONFIG)
 615                 return -EOPNOTSUPP;
 616         /* Prepare sccb. */
 617         sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 618         if (!sccb)
 619                 return -ENOMEM;
 620         sccb->header.length = sizeof(*sccb);
 621         rc = sclp_sync_request(cmd, sccb);
 622         if (rc)
 623                 goto out;
 624         switch (sccb->header.response_code) {
 625         case 0x0020:
 626         case 0x0120:
 627         case 0x0440:
 628         case 0x0450:
 629                 break;
 630         default:
 631                 pr_warning("configure channel-path failed "
 632                            "(cmd=0x%08x, response=0x%04x)\n", cmd,
 633                            sccb->header.response_code);
 634                 rc = -EIO;
 635                 break;
 636         }
 637 out:
 638         free_page((unsigned long) sccb);
 639         return rc;
 640 }
 641
 642 /**
 643  * sclp_chp_configure - perform configure channel-path sclp command
 644  * @chpid: channel-path ID
 645  *
 646  * Perform configure channel-path command sclp command for specified chpid.
 647  * Return 0 after command successfully finished, non-zero otherwise.
 648  */
 649 int sclp_chp_configure(struct chp_id chpid)
 650 {
 651         return do_chp_configure(SCLP_CMDW_CONFIGURE_CHPATH | chpid.id << 8);
 652 }
 653
 654 /**
 655  * sclp_chp_deconfigure - perform deconfigure channel-path sclp command
 656  * @chpid: channel-path ID
 657  *
 658  * Perform deconfigure channel-path command sclp command for specified chpid
 659  * and wait for completion. On success return 0. Return non-zero otherwise.
 660  */
 661 int sclp_chp_deconfigure(struct chp_id chpid)
 662 {
 663         return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8);
 664 }
 665
 666 struct chp_info_sccb {
 667         struct sccb_header header;
 668         u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
 669         u8 standby[SCLP_CHP_INFO_MASK_SIZE];
 670         u8 configured[SCLP_CHP_INFO_MASK_SIZE];
 671         u8 ccm;
 672         u8 reserved[6];
 673         u8 cssid;
 674 } __attribute__((packed));
 675
 676 /**
 677  * sclp_chp_read_info - perform read channel-path information sclp command
 678  * @info: resulting channel-path information data
 679  *
 680  * Perform read channel-path information sclp command and wait for completion.
 681  * On success, store channel-path information in @info and return 0. Return
 682  * non-zero otherwise.
 683  */
 684 int sclp_chp_read_info(struct sclp_chp_info *info)
 685 {
 686         struct chp_info_sccb *sccb;
 687         int rc;
 688
 689         if (!SCLP_HAS_CHP_INFO)
 690                 return -EOPNOTSUPP;
 691         /* Prepare sccb. */
 692         sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 693         if (!sccb)
 694                 return -ENOMEM;
 695         sccb->header.length = sizeof(*sccb);
 696         rc = sclp_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
 697         if (rc)
 698                 goto out;
 699         if (sccb->header.response_code != 0x0010) {
 700                 pr_warning("read channel-path info failed "
 701                            "(response=0x%04x)\n", sccb->header.response_code);
 702                 rc = -EIO;
 703                 goto out;
 704         }
 705         memcpy(info->recognized, sccb->recognized, SCLP_CHP_INFO_MASK_SIZE);
 706         memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE);
 707         memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE);
 708 out:
 709         free_page((unsigned long) sccb);
 710         return rc;
 711 }
 712
 713 bool sclp_has_sprp(void)
 714 {
 715         return !!(sclp_fac84 & 0x2);
 716 }