arch/s390/mm/extmem.c

   1 /*
   2  * Author(s)......: Carsten Otte <cotte@de.ibm.com>
   3  *                  Rob M van der Heij <rvdheij@nl.ibm.com>
   4  *                  Steven Shultz <shultzss@us.ibm.com>
   5  * Bugreports.to..: <Linux390@de.ibm.com>
   6  * Copyright IBM Corp. 2002, 2004
   7  */
   8
   9 #define KMSG_COMPONENT "extmem"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/string.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/list.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/bootmem.h>
  19 #include <linux/ctype.h>
  20 #include <linux/ioport.h>
  21 #include <asm/diag.h>
  22 #include <asm/page.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/ebcdic.h>
  25 #include <asm/errno.h>
  26 #include <asm/extmem.h>
  27 #include <asm/cpcmd.h>
  28 #include <asm/setup.h>
  29
  30 #define DCSS_LOADSHR    0x00
  31 #define DCSS_LOADNSR    0x04
  32 #define DCSS_PURGESEG   0x08
  33 #define DCSS_FINDSEG    0x0c
  34 #define DCSS_LOADNOLY   0x10
  35 #define DCSS_SEGEXT     0x18
  36 #define DCSS_LOADSHRX   0x20
  37 #define DCSS_LOADNSRX   0x24
  38 #define DCSS_FINDSEGX   0x2c
  39 #define DCSS_SEGEXTX    0x38
  40 #define DCSS_FINDSEGA   0x0c
  41
  42 struct qrange {
  43         unsigned long  start; /* last byte type */
  44         unsigned long  end;   /* last byte reserved */
  45 };
  46
  47 struct qout64 {
  48         unsigned long segstart;
  49         unsigned long segend;
  50         int segcnt;
  51         int segrcnt;
  52         struct qrange range[6];
  53 };
  54
  55 struct qrange_old {
  56         unsigned int start; /* last byte type */
  57         unsigned int end;   /* last byte reserved */
  58 };
  59
  60 /* output area format for the Diag x'64' old subcode x'18' */
  61 struct qout64_old {
  62         int segstart;
  63         int segend;
  64         int segcnt;
  65         int segrcnt;
  66         struct qrange_old range[6];
  67 };
  68
  69 struct qin64 {
  70         char qopcode;
  71         char rsrv1[3];
  72         char qrcode;
  73         char rsrv2[3];
  74         char qname[8];
  75         unsigned int qoutptr;
  76         short int qoutlen;
  77 };
  78
  79 struct dcss_segment {
  80         struct list_head list;
  81         char dcss_name[8];
  82         char res_name[15];
  83         unsigned long start_addr;
  84         unsigned long end;
  85         atomic_t ref_count;
  86         int do_nonshared;
  87         unsigned int vm_segtype;
  88         struct qrange range[6];
  89         int segcnt;
  90         struct resource *res;
  91 };
  92
  93 static DEFINE_MUTEX(dcss_lock);
  94 static LIST_HEAD(dcss_list);
  95 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
  96                                         "EW/EN-MIXED" };
  97 static int loadshr_scode, loadnsr_scode;
  98 static int segext_scode, purgeseg_scode;
  99 static int scode_set;
 100
 101 /* set correct Diag x'64' subcodes. */
 102 static int
 103 dcss_set_subcodes(void)
 104 {
 105         char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
 106         unsigned long rx, ry;
 107         int rc;
 108
 109         if (name == NULL)
 110                 return -ENOMEM;
 111
 112         rx = (unsigned long) name;
 113         ry = DCSS_FINDSEGX;
 114
 115         strcpy(name, "dummy");
 116         diag_stat_inc(DIAG_STAT_X064);
 117         asm volatile(
 118                 "       diag    %0,%1,0x64\n"
 119                 "0:     ipm     %2\n"
 120                 "       srl     %2,28\n"
 121                 "       j       2f\n"
 122                 "1:     la      %2,3\n"
 123                 "2:\n"
 124                 EX_TABLE(0b, 1b)
 125                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 126
 127         kfree(name);
 128         /* Diag x'64' new subcodes are supported, set to new subcodes */
 129         if (rc != 3) {
 130                 loadshr_scode = DCSS_LOADSHRX;
 131                 loadnsr_scode = DCSS_LOADNSRX;
 132                 purgeseg_scode = DCSS_PURGESEG;
 133                 segext_scode = DCSS_SEGEXTX;
 134                 return 0;
 135         }
 136         /* Diag x'64' new subcodes are not supported, set to old subcodes */
 137         loadshr_scode = DCSS_LOADNOLY;
 138         loadnsr_scode = DCSS_LOADNSR;
 139         purgeseg_scode = DCSS_PURGESEG;
 140         segext_scode = DCSS_SEGEXT;
 141         return 0;
 142 }
 143
 144 /*
 145  * Create the 8 bytes, ebcdic VM segment name from
 146  * an ascii name.
 147  */
 148 static void
 149 dcss_mkname(char *name, char *dcss_name)
 150 {
 151         int i;
 152
 153         for (i = 0; i < 8; i++) {
 154                 if (name[i] == '\0')
 155                         break;
 156                 dcss_name[i] = toupper(name[i]);
 157         };
 158         for (; i < 8; i++)
 159                 dcss_name[i] = ' ';
 160         ASCEBC(dcss_name, 8);
 161 }
 162
 163
 164 /*
 165  * search all segments in dcss_list, and return the one
 166  * namend *name. If not found, return NULL.
 167  */
 168 static struct dcss_segment *
 169 segment_by_name (char *name)
 170 {
 171         char dcss_name[9];
 172         struct list_head *l;
 173         struct dcss_segment *tmp, *retval = NULL;
 174
 175         BUG_ON(!mutex_is_locked(&dcss_lock));
 176         dcss_mkname (name, dcss_name);
 177         list_for_each (l, &dcss_list) {
 178                 tmp = list_entry (l, struct dcss_segment, list);
 179                 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
 180                         retval = tmp;
 181                         break;
 182                 }
 183         }
 184         return retval;
 185 }
 186
 187
 188 /*
 189  * Perform a function on a dcss segment.
 190  */
 191 static inline int
 192 dcss_diag(int *func, void *parameter,
 193            unsigned long *ret1, unsigned long *ret2)
 194 {
 195         unsigned long rx, ry;
 196         int rc;
 197
 198         if (scode_set == 0) {
 199                 rc = dcss_set_subcodes();
 200                 if (rc < 0)
 201                         return rc;
 202                 scode_set = 1;
 203         }
 204         rx = (unsigned long) parameter;
 205         ry = (unsigned long) *func;
 206
 207         /* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
 208         diag_stat_inc(DIAG_STAT_X064);
 209         if (*func > DCSS_SEGEXT)
 210                 asm volatile(
 211                         "       diag    %0,%1,0x64\n"
 212                         "       ipm     %2\n"
 213                         "       srl     %2,28\n"
 214                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 215         /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
 216         else
 217                 asm volatile(
 218                         "       sam31\n"
 219                         "       diag    %0,%1,0x64\n"
 220                         "       sam64\n"
 221                         "       ipm     %2\n"
 222                         "       srl     %2,28\n"
 223                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 224         *ret1 = rx;
 225         *ret2 = ry;
 226         return rc;
 227 }
 228
 229 static inline int
 230 dcss_diag_translate_rc (int vm_rc) {
 231         if (vm_rc == 44)
 232                 return -ENOENT;
 233         return -EIO;
 234 }
 235
 236
 237 /* do a diag to get info about a segment.
 238  * fills start_address, end and vm_segtype fields
 239  */
 240 static int
 241 query_segment_type (struct dcss_segment *seg)
 242 {
 243         unsigned long dummy, vmrc;
 244         int diag_cc, rc, i;
 245         struct qout64 *qout;
 246         struct qin64 *qin;
 247
 248         qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
 249         qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
 250         if ((qin == NULL) || (qout == NULL)) {
 251                 rc = -ENOMEM;
 252                 goto out_free;
 253         }
 254
 255         /* initialize diag input parameters */
 256         qin->qopcode = DCSS_FINDSEGA;
 257         qin->qoutptr = (unsigned long) qout;
 258         qin->qoutlen = sizeof(struct qout64);
 259         memcpy (qin->qname, seg->dcss_name, 8);
 260
 261         diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
 262
 263         if (diag_cc < 0) {
 264                 rc = diag_cc;
 265                 goto out_free;
 266         }
 267         if (diag_cc > 1) {
 268                 pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc);
 269                 rc = dcss_diag_translate_rc (vmrc);
 270                 goto out_free;
 271         }
 272
 273         /* Only old format of output area of Diagnose x'64' is supported,
 274            copy data for the new format. */
 275         if (segext_scode == DCSS_SEGEXT) {
 276                 struct qout64_old *qout_old;
 277                 qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
 278                 if (qout_old == NULL) {
 279                         rc = -ENOMEM;
 280                         goto out_free;
 281                 }
 282                 memcpy(qout_old, qout, sizeof(struct qout64_old));
 283                 qout->segstart = (unsigned long) qout_old->segstart;
 284                 qout->segend = (unsigned long) qout_old->segend;
 285                 qout->segcnt = qout_old->segcnt;
 286                 qout->segrcnt = qout_old->segrcnt;
 287
 288                 if (qout->segcnt > 6)
 289                         qout->segrcnt = 6;
 290                 for (i = 0; i < qout->segrcnt; i++) {
 291                         qout->range[i].start =
 292                                 (unsigned long) qout_old->range[i].start;
 293                         qout->range[i].end =
 294                                 (unsigned long) qout_old->range[i].end;
 295                 }
 296                 kfree(qout_old);
 297         }
 298         if (qout->segcnt > 6) {
 299                 rc = -EOPNOTSUPP;
 300                 goto out_free;
 301         }
 302
 303         if (qout->segcnt == 1) {
 304                 seg->vm_segtype = qout->range[0].start & 0xff;
 305         } else {
 306                 /* multi-part segment. only one type supported here:
 307                     - all parts are contiguous
 308                     - all parts are either EW or EN type
 309                     - maximum 6 parts allowed */
 310                 unsigned long start = qout->segstart >> PAGE_SHIFT;
 311                 for (i=0; i<qout->segcnt; i++) {
 312                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
 313                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
 314                                 rc = -EOPNOTSUPP;
 315                                 goto out_free;
 316                         }
 317                         if (start != qout->range[i].start >> PAGE_SHIFT) {
 318                                 rc = -EOPNOTSUPP;
 319                                 goto out_free;
 320                         }
 321                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
 322                 }
 323                 seg->vm_segtype = SEG_TYPE_EWEN;
 324         }
 325
 326         /* analyze diag output and update seg */
 327         seg->start_addr = qout->segstart;
 328         seg->end = qout->segend;
 329
 330         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
 331         seg->segcnt = qout->segcnt;
 332
 333         rc = 0;
 334
 335  out_free:
 336         kfree(qin);
 337         kfree(qout);
 338         return rc;
 339 }
 340
 341 /*
 342  * get info about a segment
 343  * possible return values:
 344  * -ENOSYS  : we are not running on VM
 345  * -EIO     : could not perform query diagnose
 346  * -ENOENT  : no such segment
 347  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 348  * -ENOMEM  : out of memory
 349  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 350  */
 351 int
 352 segment_type (char* name)
 353 {
 354         int rc;
 355         struct dcss_segment seg;
 356
 357         if (!MACHINE_IS_VM)
 358                 return -ENOSYS;
 359
 360         dcss_mkname(name, seg.dcss_name);
 361         rc = query_segment_type (&seg);
 362         if (rc < 0)
 363                 return rc;
 364         return seg.vm_segtype;
 365 }
 366
 367 /*
 368  * check if segment collides with other segments that are currently loaded
 369  * returns 1 if this is the case, 0 if no collision was found
 370  */
 371 static int
 372 segment_overlaps_others (struct dcss_segment *seg)
 373 {
 374         struct list_head *l;
 375         struct dcss_segment *tmp;
 376
 377         BUG_ON(!mutex_is_locked(&dcss_lock));
 378         list_for_each(l, &dcss_list) {
 379                 tmp = list_entry(l, struct dcss_segment, list);
 380                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
 381                         continue;
 382                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
 383                         continue;
 384                 if (seg == tmp)
 385                         continue;
 386                 return 1;
 387         }
 388         return 0;
 389 }
 390
 391 /*
 392  * real segment loading function, called from segment_load
 393  */
 394 static int
 395 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
 396 {
 397         unsigned long start_addr, end_addr, dummy;
 398         struct dcss_segment *seg;
 399         int rc, diag_cc;
 400
 401         start_addr = end_addr = 0;
 402         seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
 403         if (seg == NULL) {
 404                 rc = -ENOMEM;
 405                 goto out;
 406         }
 407         dcss_mkname (name, seg->dcss_name);
 408         rc = query_segment_type (seg);
 409         if (rc < 0)
 410                 goto out_free;
 411
 412         if (loadshr_scode == DCSS_LOADSHRX) {
 413                 if (segment_overlaps_others(seg)) {
 414                         rc = -EBUSY;
 415                         goto out_free;
 416                 }
 417         }
 418
 419         rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 420
 421         if (rc)
 422                 goto out_free;
 423
 424         seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 425         if (seg->res == NULL) {
 426                 rc = -ENOMEM;
 427                 goto out_shared;
 428         }
 429         seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 430         seg->res->start = seg->start_addr;
 431         seg->res->end = seg->end;
 432         memcpy(&seg->res_name, seg->dcss_name, 8);
 433         EBCASC(seg->res_name, 8);
 434         seg->res_name[8] = '\0';
 435         strncat(seg->res_name, " (DCSS)", 7);
 436         seg->res->name = seg->res_name;
 437         rc = seg->vm_segtype;
 438         if (rc == SEG_TYPE_SC ||
 439             ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
 440                 seg->res->flags |= IORESOURCE_READONLY;
 441         if (request_resource(&iomem_resource, seg->res)) {
 442                 rc = -EBUSY;
 443                 kfree(seg->res);
 444                 goto out_shared;
 445         }
 446
 447         if (do_nonshared)
 448                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 449                                 &start_addr, &end_addr);
 450         else
 451                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 452                                 &start_addr, &end_addr);
 453         if (diag_cc < 0) {
 454                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 455                                 &dummy, &dummy);
 456                 rc = diag_cc;
 457                 goto out_resource;
 458         }
 459         if (diag_cc > 1) {
 460                 pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr);
 461                 rc = dcss_diag_translate_rc(end_addr);
 462                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 463                                 &dummy, &dummy);
 464                 goto out_resource;
 465         }
 466         seg->start_addr = start_addr;
 467         seg->end = end_addr;
 468         seg->do_nonshared = do_nonshared;
 469         atomic_set(&seg->ref_count, 1);
 470         list_add(&seg->list, &dcss_list);
 471         *addr = seg->start_addr;
 472         *end  = seg->end;
 473         if (do_nonshared)
 474                 pr_info("DCSS %s of range %p to %p and type %s loaded as "
 475                         "exclusive-writable\n", name, (void*) seg->start_addr,
 476                         (void*) seg->end, segtype_string[seg->vm_segtype]);
 477         else {
 478                 pr_info("DCSS %s of range %p to %p and type %s loaded in "
 479                         "shared access mode\n", name, (void*) seg->start_addr,
 480                         (void*) seg->end, segtype_string[seg->vm_segtype]);
 481         }
 482         goto out;
 483  out_resource:
 484         release_resource(seg->res);
 485         kfree(seg->res);
 486  out_shared:
 487         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 488  out_free:
 489         kfree(seg);
 490  out:
 491         return rc;
 492 }
 493
 494 /*
 495  * this function loads a DCSS segment
 496  * name         : name of the DCSS
 497  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 498  *                1 indicates that the dcss should be exclusive for this linux image
 499  * addr         : will be filled with start address of the segment
 500  * end          : will be filled with end address of the segment
 501  * return values:
 502  * -ENOSYS  : we are not running on VM
 503  * -EIO     : could not perform query or load diagnose
 504  * -ENOENT  : no such segment
 505  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 506  * -ENOSPC  : segment cannot be used (overlaps with storage)
 507  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 508  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 509  * -EPERM   : segment is currently loaded with incompatible permissions
 510  * -ENOMEM  : out of memory
 511  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 512  */
 513 int
 514 segment_load (char *name, int do_nonshared, unsigned long *addr,
 515                 unsigned long *end)
 516 {
 517         struct dcss_segment *seg;
 518         int rc;
 519
 520         if (!MACHINE_IS_VM)
 521                 return -ENOSYS;
 522
 523         mutex_lock(&dcss_lock);
 524         seg = segment_by_name (name);
 525         if (seg == NULL)
 526                 rc = __segment_load (name, do_nonshared, addr, end);
 527         else {
 528                 if (do_nonshared == seg->do_nonshared) {
 529                         atomic_inc(&seg->ref_count);
 530                         *addr = seg->start_addr;
 531                         *end  = seg->end;
 532                         rc    = seg->vm_segtype;
 533                 } else {
 534                         *addr = *end = 0;
 535                         rc    = -EPERM;
 536                 }
 537         }
 538         mutex_unlock(&dcss_lock);
 539         return rc;
 540 }
 541
 542 /*
 543  * this function modifies the shared state of a DCSS segment. note that
 544  * name         : name of the DCSS
 545  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 546  *                1 indicates that the dcss should be exclusive for this linux image
 547  * return values:
 548  * -EIO     : could not perform load diagnose (segment gone!)
 549  * -ENOENT  : no such segment (segment gone!)
 550  * -EAGAIN  : segment is in use by other exploiters, try later
 551  * -EINVAL  : no segment with the given name is currently loaded - name invalid
 552  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 553  * 0        : operation succeeded
 554  */
 555 int
 556 segment_modify_shared (char *name, int do_nonshared)
 557 {
 558         struct dcss_segment *seg;
 559         unsigned long start_addr, end_addr, dummy;
 560         int rc, diag_cc;
 561
 562         start_addr = end_addr = 0;
 563         mutex_lock(&dcss_lock);
 564         seg = segment_by_name (name);
 565         if (seg == NULL) {
 566                 rc = -EINVAL;
 567                 goto out_unlock;
 568         }
 569         if (do_nonshared == seg->do_nonshared) {
 570                 pr_info("DCSS %s is already in the requested access "
 571                         "mode\n", name);
 572                 rc = 0;
 573                 goto out_unlock;
 574         }
 575         if (atomic_read (&seg->ref_count) != 1) {
 576                 pr_warn("DCSS %s is in use and cannot be reloaded\n", name);
 577                 rc = -EAGAIN;
 578                 goto out_unlock;
 579         }
 580         release_resource(seg->res);
 581         if (do_nonshared)
 582                 seg->res->flags &= ~IORESOURCE_READONLY;
 583         else
 584                 if (seg->vm_segtype == SEG_TYPE_SR ||
 585                     seg->vm_segtype == SEG_TYPE_ER)
 586                         seg->res->flags |= IORESOURCE_READONLY;
 587
 588         if (request_resource(&iomem_resource, seg->res)) {
 589                 pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n",
 590                         name);
 591                 rc = -EBUSY;
 592                 kfree(seg->res);
 593                 goto out_del_mem;
 594         }
 595
 596         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 597         if (do_nonshared)
 598                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 599                                 &start_addr, &end_addr);
 600         else
 601                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 602                                 &start_addr, &end_addr);
 603         if (diag_cc < 0) {
 604                 rc = diag_cc;
 605                 goto out_del_res;
 606         }
 607         if (diag_cc > 1) {
 608                 pr_warn("Reloading DCSS %s failed with rc=%ld\n",
 609                         name, end_addr);
 610                 rc = dcss_diag_translate_rc(end_addr);
 611                 goto out_del_res;
 612         }
 613         seg->start_addr = start_addr;
 614         seg->end = end_addr;
 615         seg->do_nonshared = do_nonshared;
 616         rc = 0;
 617         goto out_unlock;
 618  out_del_res:
 619         release_resource(seg->res);
 620         kfree(seg->res);
 621  out_del_mem:
 622         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 623         list_del(&seg->list);
 624         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 625         kfree(seg);
 626  out_unlock:
 627         mutex_unlock(&dcss_lock);
 628         return rc;
 629 }
 630
 631 /*
 632  * Decrease the use count of a DCSS segment and remove
 633  * it from the address space if nobody is using it
 634  * any longer.
 635  */
 636 void
 637 segment_unload(char *name)
 638 {
 639         unsigned long dummy;
 640         struct dcss_segment *seg;
 641
 642         if (!MACHINE_IS_VM)
 643                 return;
 644
 645         mutex_lock(&dcss_lock);
 646         seg = segment_by_name (name);
 647         if (seg == NULL) {
 648                 pr_err("Unloading unknown DCSS %s failed\n", name);
 649                 goto out_unlock;
 650         }
 651         if (atomic_dec_return(&seg->ref_count) != 0)
 652                 goto out_unlock;
 653         release_resource(seg->res);
 654         kfree(seg->res);
 655         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 656         list_del(&seg->list);
 657         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 658         kfree(seg);
 659 out_unlock:
 660         mutex_unlock(&dcss_lock);
 661 }
 662
 663 /*
 664  * save segment content permanently
 665  */
 666 void
 667 segment_save(char *name)
 668 {
 669         struct dcss_segment *seg;
 670         char cmd1[160];
 671         char cmd2[80];
 672         int i, response;
 673
 674         if (!MACHINE_IS_VM)
 675                 return;
 676
 677         mutex_lock(&dcss_lock);
 678         seg = segment_by_name (name);
 679
 680         if (seg == NULL) {
 681                 pr_err("Saving unknown DCSS %s failed\n", name);
 682                 goto out;
 683         }
 684
 685         sprintf(cmd1, "DEFSEG %s", name);
 686         for (i=0; i<seg->segcnt; i++) {
 687                 sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
 688                         seg->range[i].start >> PAGE_SHIFT,
 689                         seg->range[i].end >> PAGE_SHIFT,
 690                         segtype_string[seg->range[i].start & 0xff]);
 691         }
 692         sprintf(cmd2, "SAVESEG %s", name);
 693         response = 0;
 694         cpcmd(cmd1, NULL, 0, &response);
 695         if (response) {
 696                 pr_err("Saving a DCSS failed with DEFSEG response code "
 697                        "%i\n", response);
 698                 goto out;
 699         }
 700         cpcmd(cmd2, NULL, 0, &response);
 701         if (response) {
 702                 pr_err("Saving a DCSS failed with SAVESEG response code "
 703                        "%i\n", response);
 704                 goto out;
 705         }
 706 out:
 707         mutex_unlock(&dcss_lock);
 708 }
 709
 710 /*
 711  * print appropriate error message for segment_load()/segment_type()
 712  * return code
 713  */
 714 void segment_warning(int rc, char *seg_name)
 715 {
 716         switch (rc) {
 717         case -ENOENT:
 718                 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
 719                 break;
 720         case -ENOSYS:
 721                 pr_err("DCSS %s cannot be loaded or queried without "
 722                        "z/VM\n", seg_name);
 723                 break;
 724         case -EIO:
 725                 pr_err("Loading or querying DCSS %s resulted in a "
 726                        "hardware error\n", seg_name);
 727                 break;
 728         case -EOPNOTSUPP:
 729                 pr_err("DCSS %s has multiple page ranges and cannot be "
 730                        "loaded or queried\n", seg_name);
 731                 break;
 732         case -ENOSPC:
 733                 pr_err("DCSS %s overlaps with used storage and cannot "
 734                        "be loaded\n", seg_name);
 735                 break;
 736         case -EBUSY:
 737                 pr_err("%s needs used memory resources and cannot be "
 738                        "loaded or queried\n", seg_name);
 739                 break;
 740         case -EPERM:
 741                 pr_err("DCSS %s is already loaded in a different access "
 742                        "mode\n", seg_name);
 743                 break;
 744         case -ENOMEM:
 745                 pr_err("There is not enough memory to load or query "
 746                        "DCSS %s\n", seg_name);
 747                 break;
 748         case -ERANGE:
 749                 pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
 750                        "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
 751                 break;
 752         default:
 753                 break;
 754         }
 755 }
 756
 757 EXPORT_SYMBOL(segment_load);
 758 EXPORT_SYMBOL(segment_unload);
 759 EXPORT_SYMBOL(segment_save);
 760 EXPORT_SYMBOL(segment_type);
 761 EXPORT_SYMBOL(segment_modify_shared);
 762 EXPORT_SYMBOL(segment_warning);