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