drivers/s390/char/sclp_cmd.c

   1 /*
   2  *  drivers/s390/char/sclp_cmd.c
   3  *
   4  *    Copyright IBM Corp. 2007
   5  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
   6  *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   7  */
   8
   9 #include <linux/completion.h>
  10 #include <linux/init.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/string.h>
  14 #include <linux/mm.h>
  15 #include <linux/mmzone.h>
  16 #include <linux/memory.h>
  17 #include <asm/chpid.h>
  18 #include <asm/sclp.h>
  19 #include "sclp.h"
  20
  21 #define TAG     "sclp_cmd: "
  22
  23 #define SCLP_CMDW_READ_SCP_INFO         0x00020001
  24 #define SCLP_CMDW_READ_SCP_INFO_FORCED  0x00120001
  25
  26 struct read_info_sccb {
  27         struct  sccb_header header;     /* 0-7 */
  28         u16     rnmax;                  /* 8-9 */
  29         u8      rnsize;                 /* 10 */
  30         u8      _reserved0[24 - 11];    /* 11-15 */
  31         u8      loadparm[8];            /* 24-31 */
  32         u8      _reserved1[48 - 32];    /* 32-47 */
  33         u64     facilities;             /* 48-55 */
  34         u8      _reserved2[84 - 56];    /* 56-83 */
  35         u8      fac84;                  /* 84 */
  36         u8      _reserved3[91 - 85];    /* 85-90 */
  37         u8      flags;                  /* 91 */
  38         u8      _reserved4[100 - 92];   /* 92-99 */
  39         u32     rnsize2;                /* 100-103 */
  40         u64     rnmax2;                 /* 104-111 */
  41         u8      _reserved5[4096 - 112]; /* 112-4095 */
  42 } __attribute__((packed, aligned(PAGE_SIZE)));
  43
  44 static struct read_info_sccb __initdata early_read_info_sccb;
  45 static int __initdata early_read_info_sccb_valid;
  46
  47 u64 sclp_facilities;
  48 static u8 sclp_fac84;
  49 static unsigned long long rzm;
  50 static unsigned long long rnmax;
  51
  52 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
  53 {
  54         int rc;
  55
  56         __ctl_set_bit(0, 9);
  57         rc = sclp_service_call(cmd, sccb);
  58         if (rc)
  59                 goto out;
  60         __load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
  61                         PSW_MASK_WAIT | PSW_DEFAULT_KEY);
  62         local_irq_disable();
  63 out:
  64         /* Contents of the sccb might have changed. */
  65         barrier();
  66         __ctl_clear_bit(0, 9);
  67         return rc;
  68 }
  69
  70 static void __init sclp_read_info_early(void)
  71 {
  72         int rc;
  73         int i;
  74         struct read_info_sccb *sccb;
  75         sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
  76                                   SCLP_CMDW_READ_SCP_INFO};
  77
  78         sccb = &early_read_info_sccb;
  79         for (i = 0; i < ARRAY_SIZE(commands); i++) {
  80                 do {
  81                         memset(sccb, 0, sizeof(*sccb));
  82                         sccb->header.length = sizeof(*sccb);
  83                         sccb->header.control_mask[2] = 0x80;
  84                         rc = sclp_cmd_sync_early(commands[i], sccb);
  85                 } while (rc == -EBUSY);
  86
  87                 if (rc)
  88                         break;
  89                 if (sccb->header.response_code == 0x10) {
  90                         early_read_info_sccb_valid = 1;
  91                         break;
  92                 }
  93                 if (sccb->header.response_code != 0x1f0)
  94                         break;
  95         }
  96 }
  97
  98 void __init sclp_facilities_detect(void)
  99 {
 100         struct read_info_sccb *sccb;
 101
 102         sclp_read_info_early();
 103         if (!early_read_info_sccb_valid)
 104                 return;
 105
 106         sccb = &early_read_info_sccb;
 107         sclp_facilities = sccb->facilities;
 108         sclp_fac84 = sccb->fac84;
 109         rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
 110         rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
 111         rzm <<= 20;
 112 }
 113
 114 unsigned long long sclp_get_rnmax(void)
 115 {
 116         return rnmax;
 117 }
 118
 119 unsigned long long sclp_get_rzm(void)
 120 {
 121         return rzm;
 122 }
 123
 124 /*
 125  * This function will be called after sclp_facilities_detect(), which gets
 126  * called from early.c code. Therefore the sccb should have valid contents.
 127  */
 128 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
 129 {
 130         struct read_info_sccb *sccb;
 131
 132         if (!early_read_info_sccb_valid)
 133                 return;
 134         sccb = &early_read_info_sccb;
 135         info->is_valid = 1;
 136         if (sccb->flags & 0x2)
 137                 info->has_dump = 1;
 138         memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
 139 }
 140
 141 static void sclp_sync_callback(struct sclp_req *req, void *data)
 142 {
 143         struct completion *completion = data;
 144
 145         complete(completion);
 146 }
 147
 148 static int do_sync_request(sclp_cmdw_t cmd, void *sccb)
 149 {
 150         struct completion completion;
 151         struct sclp_req *request;
 152         int rc;
 153
 154         request = kzalloc(sizeof(*request), GFP_KERNEL);
 155         if (!request)
 156                 return -ENOMEM;
 157         request->command = cmd;
 158         request->sccb = sccb;
 159         request->status = SCLP_REQ_FILLED;
 160         request->callback = sclp_sync_callback;
 161         request->callback_data = &completion;
 162         init_completion(&completion);
 163
 164         /* Perform sclp request. */
 165         rc = sclp_add_request(request);
 166         if (rc)
 167                 goto out;
 168         wait_for_completion(&completion);
 169
 170         /* Check response. */
 171         if (request->status != SCLP_REQ_DONE) {
 172                 printk(KERN_WARNING TAG "sync request failed "
 173                        "(cmd=0x%08x, status=0x%02x)\n", cmd, request->status);
 174                 rc = -EIO;
 175         }
 176 out:
 177         kfree(request);
 178         return rc;
 179 }
 180
 181 /*
 182  * CPU configuration related functions.
 183  */
 184
 185 #define SCLP_CMDW_READ_CPU_INFO         0x00010001
 186 #define SCLP_CMDW_CONFIGURE_CPU         0x00110001
 187 #define SCLP_CMDW_DECONFIGURE_CPU       0x00100001
 188
 189 struct read_cpu_info_sccb {
 190         struct  sccb_header header;
 191         u16     nr_configured;
 192         u16     offset_configured;
 193         u16     nr_standby;
 194         u16     offset_standby;
 195         u8      reserved[4096 - 16];
 196 } __attribute__((packed, aligned(PAGE_SIZE)));
 197
 198 static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
 199                                struct read_cpu_info_sccb *sccb)
 200 {
 201         char *page = (char *) sccb;
 202
 203         memset(info, 0, sizeof(*info));
 204         info->configured = sccb->nr_configured;
 205         info->standby = sccb->nr_standby;
 206         info->combined = sccb->nr_configured + sccb->nr_standby;
 207         info->has_cpu_type = sclp_fac84 & 0x1;
 208         memcpy(&info->cpu, page + sccb->offset_configured,
 209                info->combined * sizeof(struct sclp_cpu_entry));
 210 }
 211
 212 int sclp_get_cpu_info(struct sclp_cpu_info *info)
 213 {
 214         int rc;
 215         struct read_cpu_info_sccb *sccb;
 216
 217         if (!SCLP_HAS_CPU_INFO)
 218                 return -EOPNOTSUPP;
 219         sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 220         if (!sccb)
 221                 return -ENOMEM;
 222         sccb->header.length = sizeof(*sccb);
 223         rc = do_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
 224         if (rc)
 225                 goto out;
 226         if (sccb->header.response_code != 0x0010) {
 227                 printk(KERN_WARNING TAG "readcpuinfo failed "
 228                        "(response=0x%04x)\n", sccb->header.response_code);
 229                 rc = -EIO;
 230                 goto out;
 231         }
 232         sclp_fill_cpu_info(info, sccb);
 233 out:
 234         free_page((unsigned long) sccb);
 235         return rc;
 236 }
 237
 238 struct cpu_configure_sccb {
 239         struct sccb_header header;
 240 } __attribute__((packed, aligned(8)));
 241
 242 static int do_cpu_configure(sclp_cmdw_t cmd)
 243 {
 244         struct cpu_configure_sccb *sccb;
 245         int rc;
 246
 247         if (!SCLP_HAS_CPU_RECONFIG)
 248                 return -EOPNOTSUPP;
 249         /*
 250          * This is not going to cross a page boundary since we force
 251          * kmalloc to have a minimum alignment of 8 bytes on s390.
 252          */
 253         sccb = kzalloc(sizeof(*sccb), GFP_KERNEL | GFP_DMA);
 254         if (!sccb)
 255                 return -ENOMEM;
 256         sccb->header.length = sizeof(*sccb);
 257         rc = do_sync_request(cmd, sccb);
 258         if (rc)
 259                 goto out;
 260         switch (sccb->header.response_code) {
 261         case 0x0020:
 262         case 0x0120:
 263                 break;
 264         default:
 265                 printk(KERN_WARNING TAG "configure cpu failed (cmd=0x%08x, "
 266                        "response=0x%04x)\n", cmd, sccb->header.response_code);
 267                 rc = -EIO;
 268                 break;
 269         }
 270 out:
 271         kfree(sccb);
 272         return rc;
 273 }
 274
 275 int sclp_cpu_configure(u8 cpu)
 276 {
 277         return do_cpu_configure(SCLP_CMDW_CONFIGURE_CPU | cpu << 8);
 278 }
 279
 280 int sclp_cpu_deconfigure(u8 cpu)
 281 {
 282         return do_cpu_configure(SCLP_CMDW_DECONFIGURE_CPU | cpu << 8);
 283 }
 284
 285 #ifdef CONFIG_MEMORY_HOTPLUG
 286
 287 static DEFINE_MUTEX(sclp_mem_mutex);
 288 static LIST_HEAD(sclp_mem_list);
 289 static u8 sclp_max_storage_id;
 290 static unsigned long sclp_storage_ids[256 / BITS_PER_LONG];
 291
 292 struct memory_increment {
 293         struct list_head list;
 294         u16 rn;
 295         int standby;
 296         int usecount;
 297 };
 298
 299 struct assign_storage_sccb {
 300         struct sccb_header header;
 301         u16 rn;
 302 } __packed;
 303
 304 static unsigned long long rn2addr(u16 rn)
 305 {
 306         return (unsigned long long) (rn - 1) * rzm;
 307 }
 308
 309 static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
 310 {
 311         struct assign_storage_sccb *sccb;
 312         int rc;
 313
 314         sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 315         if (!sccb)
 316                 return -ENOMEM;
 317         sccb->header.length = PAGE_SIZE;
 318         sccb->rn = rn;
 319         rc = do_sync_request(cmd, sccb);
 320         if (rc)
 321                 goto out;
 322         switch (sccb->header.response_code) {
 323         case 0x0020:
 324         case 0x0120:
 325                 break;
 326         default:
 327                 pr_warning("assign storage failed (cmd=0x%08x, "
 328                            "response=0x%04x, rn=0x%04x)\n", cmd,
 329                            sccb->header.response_code, rn);
 330                 rc = -EIO;
 331                 break;
 332         }
 333 out:
 334         free_page((unsigned long) sccb);
 335         return rc;
 336 }
 337
 338 static int sclp_assign_storage(u16 rn)
 339 {
 340         return do_assign_storage(0x000d0001, rn);
 341 }
 342
 343 static int sclp_unassign_storage(u16 rn)
 344 {
 345         return do_assign_storage(0x000c0001, rn);
 346 }
 347
 348 struct attach_storage_sccb {
 349         struct sccb_header header;
 350         u16 :16;
 351         u16 assigned;
 352         u32 :32;
 353         u32 entries[0];
 354 } __packed;
 355
 356 static int sclp_attach_storage(u8 id)
 357 {
 358         struct attach_storage_sccb *sccb;
 359         int rc;
 360         int i;
 361
 362         sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 363         if (!sccb)
 364                 return -ENOMEM;
 365         sccb->header.length = PAGE_SIZE;
 366         rc = do_sync_request(0x00080001 | id << 8, sccb);
 367         if (rc)
 368                 goto out;
 369         switch (sccb->header.response_code) {
 370         case 0x0020:
 371                 set_bit(id, sclp_storage_ids);
 372                 for (i = 0; i < sccb->assigned; i++)
 373                         sclp_unassign_storage(sccb->entries[i] >> 16);
 374                 break;
 375         default:
 376                 rc = -EIO;
 377                 break;
 378         }
 379 out:
 380         free_page((unsigned long) sccb);
 381         return rc;
 382 }
 383
 384 static int sclp_mem_change_state(unsigned long start, unsigned long size,
 385                                  int online)
 386 {
 387         struct memory_increment *incr;
 388         unsigned long long istart;
 389         int rc = 0;
 390
 391         list_for_each_entry(incr, &sclp_mem_list, list) {
 392                 istart = rn2addr(incr->rn);
 393                 if (start + size - 1 < istart)
 394                         break;
 395                 if (start > istart + rzm - 1)
 396                         continue;
 397                 if (online) {
 398                         if (incr->usecount++)
 399                                 continue;
 400                         /*
 401                          * Don't break the loop if one assign fails. Loop may
 402                          * be walked again on CANCEL and we can't save
 403                          * information if state changed before or not.
 404                          * So continue and increase usecount for all increments.
 405                          */
 406                         rc |= sclp_assign_storage(incr->rn);
 407                 } else {
 408                         if (--incr->usecount)
 409                                 continue;
 410                         sclp_unassign_storage(incr->rn);
 411                 }
 412         }
 413         return rc ? -EIO : 0;
 414 }
 415
 416 static int sclp_mem_notifier(struct notifier_block *nb,
 417                              unsigned long action, void *data)
 418 {
 419         unsigned long start, size;
 420         struct memory_notify *arg;
 421         unsigned char id;
 422         int rc = 0;
 423
 424         arg = data;
 425         start = arg->start_pfn << PAGE_SHIFT;
 426         size = arg->nr_pages << PAGE_SHIFT;
 427         mutex_lock(&sclp_mem_mutex);
 428         for (id = 0; id <= sclp_max_storage_id; id++)
 429                 if (!test_bit(id, sclp_storage_ids))
 430                         sclp_attach_storage(id);
 431         switch (action) {
 432         case MEM_ONLINE:
 433         case MEM_GOING_OFFLINE:
 434         case MEM_CANCEL_OFFLINE:
 435                 break;
 436         case MEM_GOING_ONLINE:
 437                 rc = sclp_mem_change_state(start, size, 1);
 438                 break;
 439         case MEM_CANCEL_ONLINE:
 440                 sclp_mem_change_state(start, size, 0);
 441                 break;
 442         case MEM_OFFLINE:
 443                 sclp_mem_change_state(start, size, 0);
 444                 break;
 445         default:
 446                 rc = -EINVAL;
 447                 break;
 448         }
 449         mutex_unlock(&sclp_mem_mutex);
 450         return rc ? NOTIFY_BAD : NOTIFY_OK;
 451 }
 452
 453 static struct notifier_block sclp_mem_nb = {
 454         .notifier_call = sclp_mem_notifier,
 455 };
 456
 457 static void __init add_memory_merged(u16 rn)
 458 {
 459         static u16 first_rn, num;
 460         unsigned long long start, size;
 461
 462         if (rn && first_rn && (first_rn + num == rn)) {
 463                 num++;
 464                 return;
 465         }
 466         if (!first_rn)
 467                 goto skip_add;
 468         start = rn2addr(first_rn);
 469         size = (unsigned long long ) num * rzm;
 470         if (start >= VMEM_MAX_PHYS)
 471                 goto skip_add;
 472         if (start + size > VMEM_MAX_PHYS)
 473                 size = VMEM_MAX_PHYS - start;
 474         add_memory(0, start, size);
 475 skip_add:
 476         first_rn = rn;
 477         num = 1;
 478 }
 479
 480 static void __init sclp_add_standby_memory(void)
 481 {
 482         struct memory_increment *incr;
 483
 484         list_for_each_entry(incr, &sclp_mem_list, list)
 485                 if (incr->standby)
 486                         add_memory_merged(incr->rn);
 487         add_memory_merged(0);
 488 }
 489
 490 static void __init insert_increment(u16 rn, int standby, int assigned)
 491 {
 492         struct memory_increment *incr, *new_incr;
 493         struct list_head *prev;
 494         u16 last_rn;
 495
 496         new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
 497         if (!new_incr)
 498                 return;
 499         new_incr->rn = rn;
 500         new_incr->standby = standby;
 501         last_rn = 0;
 502         prev = &sclp_mem_list;
 503         list_for_each_entry(incr, &sclp_mem_list, list) {
 504                 if (assigned && incr->rn > rn)
 505                         break;
 506                 if (!assigned && incr->rn - last_rn > 1)
 507                         break;
 508                 last_rn = incr->rn;
 509                 prev = &incr->list;
 510         }
 511         if (!assigned)
 512                 new_incr->rn = last_rn + 1;
 513         if (new_incr->rn > rnmax) {
 514                 kfree(new_incr);
 515                 return;
 516         }
 517         list_add(&new_incr->list, prev);
 518 }
 519
 520 struct read_storage_sccb {
 521         struct sccb_header header;
 522         u16 max_id;
 523         u16 assigned;
 524         u16 standby;
 525         u16 :16;
 526         u32 entries[0];
 527 } __packed;
 528
 529 static int __init sclp_detect_standby_memory(void)
 530 {
 531         struct read_storage_sccb *sccb;
 532         int i, id, assigned, rc;
 533
 534         if (!early_read_info_sccb_valid)
 535                 return 0;
 536         if ((sclp_facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
 537                 return 0;
 538         rc = -ENOMEM;
 539         sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
 540         if (!sccb)
 541                 goto out;
 542         assigned = 0;
 543         for (id = 0; id <= sclp_max_storage_id; id++) {
 544                 memset(sccb, 0, PAGE_SIZE);
 545                 sccb->header.length = PAGE_SIZE;
 546                 rc = do_sync_request(0x00040001 | id << 8, sccb);
 547                 if (rc)
 548                         goto out;
 549                 switch (sccb->header.response_code) {
 550                 case 0x0010:
 551                         set_bit(id, sclp_storage_ids);
 552                         for (i = 0; i < sccb->assigned; i++) {
 553                                 if (!sccb->entries[i])
 554                                         continue;
 555                                 assigned++;
 556                                 insert_increment(sccb->entries[i] >> 16, 0, 1);
 557                         }
 558                         break;
 559                 case 0x0310:
 560                         break;
 561                 case 0x0410:
 562                         for (i = 0; i < sccb->assigned; i++) {
 563                                 if (!sccb->entries[i])
 564                                         continue;
 565                                 assigned++;
 566                                 insert_increment(sccb->entries[i] >> 16, 1, 1);
 567                         }
 568                         break;
 569                 default:
 570                         rc = -EIO;
 571                         break;
 572                 }
 573                 if (!rc)
 574                         sclp_max_storage_id = sccb->max_id;
 575         }
 576         if (rc || list_empty(&sclp_mem_list))
 577                 goto out;
 578         for (i = 1; i <= rnmax - assigned; i++)
 579                 insert_increment(0, 1, 0);
 580         rc = register_memory_notifier(&sclp_mem_nb);
 581         if (rc)
 582                 goto out;
 583         sclp_add_standby_memory();
 584 out:
 585         free_page((unsigned long) sccb);
 586         return rc;
 587 }
 588 __initcall(sclp_detect_standby_memory);
 589
 590 #endif /* CONFIG_MEMORY_HOTPLUG */
 591
 592 /*
 593  * Channel path configuration related functions.
 594  */
 595
 596 #define SCLP_CMDW_CONFIGURE_CHPATH              0x000f0001
 597 #define SCLP_CMDW_DECONFIGURE_CHPATH            0x000e0001
 598 #define SCLP_CMDW_READ_CHPATH_INFORMATION       0x00030001
 599
 600 struct chp_cfg_sccb {
 601         struct sccb_header header;
 602         u8 ccm;
 603         u8 reserved[6];
 604         u8 cssid;
 605 } __attribute__((packed));
 606
 607 static int do_chp_configure(sclp_cmdw_t cmd)
 608 {
 609         struct chp_cfg_sccb *sccb;
 610         int rc;
 611
 612         if (!SCLP_HAS_CHP_RECONFIG)
 613                 return -EOPNOTSUPP;
 614         /* Prepare sccb. */
 615         sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 616         if (!sccb)
 617                 return -ENOMEM;
 618         sccb->header.length = sizeof(*sccb);
 619         rc = do_sync_request(cmd, sccb);
 620         if (rc)
 621                 goto out;
 622         switch (sccb->header.response_code) {
 623         case 0x0020:
 624         case 0x0120:
 625         case 0x0440:
 626         case 0x0450:
 627                 break;
 628         default:
 629                 printk(KERN_WARNING TAG "configure channel-path failed "
 630                        "(cmd=0x%08x, response=0x%04x)\n", cmd,
 631                        sccb->header.response_code);
 632                 rc = -EIO;
 633                 break;
 634         }
 635 out:
 636         free_page((unsigned long) sccb);
 637         return rc;
 638 }
 639
 640 /**
 641  * sclp_chp_configure - perform configure channel-path sclp command
 642  * @chpid: channel-path ID
 643  *
 644  * Perform configure channel-path command sclp command for specified chpid.
 645  * Return 0 after command successfully finished, non-zero otherwise.
 646  */
 647 int sclp_chp_configure(struct chp_id chpid)
 648 {
 649         return do_chp_configure(SCLP_CMDW_CONFIGURE_CHPATH | chpid.id << 8);
 650 }
 651
 652 /**
 653  * sclp_chp_deconfigure - perform deconfigure channel-path sclp command
 654  * @chpid: channel-path ID
 655  *
 656  * Perform deconfigure channel-path command sclp command for specified chpid
 657  * and wait for completion. On success return 0. Return non-zero otherwise.
 658  */
 659 int sclp_chp_deconfigure(struct chp_id chpid)
 660 {
 661         return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8);
 662 }
 663
 664 struct chp_info_sccb {
 665         struct sccb_header header;
 666         u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
 667         u8 standby[SCLP_CHP_INFO_MASK_SIZE];
 668         u8 configured[SCLP_CHP_INFO_MASK_SIZE];
 669         u8 ccm;
 670         u8 reserved[6];
 671         u8 cssid;
 672 } __attribute__((packed));
 673
 674 /**
 675  * sclp_chp_read_info - perform read channel-path information sclp command
 676  * @info: resulting channel-path information data
 677  *
 678  * Perform read channel-path information sclp command and wait for completion.
 679  * On success, store channel-path information in @info and return 0. Return
 680  * non-zero otherwise.
 681  */
 682 int sclp_chp_read_info(struct sclp_chp_info *info)
 683 {
 684         struct chp_info_sccb *sccb;
 685         int rc;
 686
 687         if (!SCLP_HAS_CHP_INFO)
 688                 return -EOPNOTSUPP;
 689         /* Prepare sccb. */
 690         sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 691         if (!sccb)
 692                 return -ENOMEM;
 693         sccb->header.length = sizeof(*sccb);
 694         rc = do_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
 695         if (rc)
 696                 goto out;
 697         if (sccb->header.response_code != 0x0010) {
 698                 printk(KERN_WARNING TAG "read channel-path info failed "
 699                        "(response=0x%04x)\n", sccb->header.response_code);
 700                 rc = -EIO;
 701                 goto out;
 702         }
 703         memcpy(info->recognized, sccb->recognized, SCLP_CHP_INFO_MASK_SIZE);
 704         memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE);
 705         memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE);
 706 out:
 707         free_page((unsigned long) sccb);
 708         return rc;
 709 }