arch/s390/mm/extmem.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Carsten Otte <[email protected]>
   4  *                  Rob M van der Heij <[email protected]>
   5  *                  Steven Shultz <[email protected]>
   6  * Bugreports.to..: <[email protected]>
   7  * Copyright IBM Corp. 2002, 2004
   8  */
   9
  10 #define KMSG_COMPONENT "extmem"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kernel.h>
  14 #include <linux/string.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/list.h>
  17 #include <linux/slab.h>
  18 #include <linux/export.h>
  19 #include <linux/bootmem.h>
  20 #include <linux/ctype.h>
  21 #include <linux/ioport.h>
  22 #include <asm/diag.h>
  23 #include <asm/page.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/ebcdic.h>
  26 #include <asm/errno.h>
  27 #include <asm/extmem.h>
  28 #include <asm/cpcmd.h>
  29 #include <asm/setup.h>
  30
  31 #define DCSS_LOADSHR    0x00
  32 #define DCSS_LOADNSR    0x04
  33 #define DCSS_PURGESEG   0x08
  34 #define DCSS_FINDSEG    0x0c
  35 #define DCSS_LOADNOLY   0x10
  36 #define DCSS_SEGEXT     0x18
  37 #define DCSS_LOADSHRX   0x20
  38 #define DCSS_LOADNSRX   0x24
  39 #define DCSS_FINDSEGX   0x2c
  40 #define DCSS_SEGEXTX    0x38
  41 #define DCSS_FINDSEGA   0x0c
  42
  43 struct qrange {
  44         unsigned long  start; /* last byte type */
  45         unsigned long  end;   /* last byte reserved */
  46 };
  47
  48 struct qout64 {
  49         unsigned long segstart;
  50         unsigned long segend;
  51         int segcnt;
  52         int segrcnt;
  53         struct qrange range[6];
  54 };
  55
  56 struct qrange_old {
  57         unsigned int start; /* last byte type */
  58         unsigned int end;   /* last byte reserved */
  59 };
  60
  61 /* output area format for the Diag x'64' old subcode x'18' */
  62 struct qout64_old {
  63         int segstart;
  64         int segend;
  65         int segcnt;
  66         int segrcnt;
  67         struct qrange_old range[6];
  68 };
  69
  70 struct qin64 {
  71         char qopcode;
  72         char rsrv1[3];
  73         char qrcode;
  74         char rsrv2[3];
  75         char qname[8];
  76         unsigned int qoutptr;
  77         short int qoutlen;
  78 };
  79
  80 struct dcss_segment {
  81         struct list_head list;
  82         char dcss_name[8];
  83         char res_name[15];
  84         unsigned long start_addr;
  85         unsigned long end;
  86         atomic_t ref_count;
  87         int do_nonshared;
  88         unsigned int vm_segtype;
  89         struct qrange range[6];
  90         int segcnt;
  91         struct resource *res;
  92 };
  93
  94 static DEFINE_MUTEX(dcss_lock);
  95 static LIST_HEAD(dcss_list);
  96 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
  97                                         "EW/EN-MIXED" };
  98 static int loadshr_scode, loadnsr_scode;
  99 static int segext_scode, purgeseg_scode;
 100 static int scode_set;
 101
 102 /* set correct Diag x'64' subcodes. */
 103 static int
 104 dcss_set_subcodes(void)
 105 {
 106         char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
 107         unsigned long rx, ry;
 108         int rc;
 109
 110         if (name == NULL)
 111                 return -ENOMEM;
 112
 113         rx = (unsigned long) name;
 114         ry = DCSS_FINDSEGX;
 115
 116         strcpy(name, "dummy");
 117         diag_stat_inc(DIAG_STAT_X064);
 118         asm volatile(
 119                 "       diag    %0,%1,0x64\n"
 120                 "0:     ipm     %2\n"
 121                 "       srl     %2,28\n"
 122                 "       j       2f\n"
 123                 "1:     la      %2,3\n"
 124                 "2:\n"
 125                 EX_TABLE(0b, 1b)
 126                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc", "memory");
 127
 128         kfree(name);
 129         /* Diag x'64' new subcodes are supported, set to new subcodes */
 130         if (rc != 3) {
 131                 loadshr_scode = DCSS_LOADSHRX;
 132                 loadnsr_scode = DCSS_LOADNSRX;
 133                 purgeseg_scode = DCSS_PURGESEG;
 134                 segext_scode = DCSS_SEGEXTX;
 135                 return 0;
 136         }
 137         /* Diag x'64' new subcodes are not supported, set to old subcodes */
 138         loadshr_scode = DCSS_LOADNOLY;
 139         loadnsr_scode = DCSS_LOADNSR;
 140         purgeseg_scode = DCSS_PURGESEG;
 141         segext_scode = DCSS_SEGEXT;
 142         return 0;
 143 }
 144
 145 /*
 146  * Create the 8 bytes, ebcdic VM segment name from
 147  * an ascii name.
 148  */
 149 static void
 150 dcss_mkname(char *name, char *dcss_name)
 151 {
 152         int i;
 153
 154         for (i = 0; i < 8; i++) {
 155                 if (name[i] == '\0')
 156                         break;
 157                 dcss_name[i] = toupper(name[i]);
 158         }
 159         for (; i < 8; i++)
 160                 dcss_name[i] = ' ';
 161         ASCEBC(dcss_name, 8);
 162 }
 163
 164
 165 /*
 166  * search all segments in dcss_list, and return the one
 167  * namend *name. If not found, return NULL.
 168  */
 169 static struct dcss_segment *
 170 segment_by_name (char *name)
 171 {
 172         char dcss_name[9];
 173         struct list_head *l;
 174         struct dcss_segment *tmp, *retval = NULL;
 175
 176         BUG_ON(!mutex_is_locked(&dcss_lock));
 177         dcss_mkname (name, dcss_name);
 178         list_for_each (l, &dcss_list) {
 179                 tmp = list_entry (l, struct dcss_segment, list);
 180                 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
 181                         retval = tmp;
 182                         break;
 183                 }
 184         }
 185         return retval;
 186 }
 187
 188
 189 /*
 190  * Perform a function on a dcss segment.
 191  */
 192 static inline int
 193 dcss_diag(int *func, void *parameter,
 194            unsigned long *ret1, unsigned long *ret2)
 195 {
 196         unsigned long rx, ry;
 197         int rc;
 198
 199         if (scode_set == 0) {
 200                 rc = dcss_set_subcodes();
 201                 if (rc < 0)
 202                         return rc;
 203                 scode_set = 1;
 204         }
 205         rx = (unsigned long) parameter;
 206         ry = (unsigned long) *func;
 207
 208         /* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
 209         diag_stat_inc(DIAG_STAT_X064);
 210         if (*func > DCSS_SEGEXT)
 211                 asm volatile(
 212                         "       diag    %0,%1,0x64\n"
 213                         "       ipm     %2\n"
 214                         "       srl     %2,28\n"
 215                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 216         /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
 217         else
 218                 asm volatile(
 219                         "       sam31\n"
 220                         "       diag    %0,%1,0x64\n"
 221                         "       sam64\n"
 222                         "       ipm     %2\n"
 223                         "       srl     %2,28\n"
 224                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 225         *ret1 = rx;
 226         *ret2 = ry;
 227         return rc;
 228 }
 229
 230 static inline int
 231 dcss_diag_translate_rc (int vm_rc) {
 232         if (vm_rc == 44)
 233                 return -ENOENT;
 234         return -EIO;
 235 }
 236
 237
 238 /* do a diag to get info about a segment.
 239  * fills start_address, end and vm_segtype fields
 240  */
 241 static int
 242 query_segment_type (struct dcss_segment *seg)
 243 {
 244         unsigned long dummy, vmrc;
 245         int diag_cc, rc, i;
 246         struct qout64 *qout;
 247         struct qin64 *qin;
 248
 249         qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
 250         qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
 251         if ((qin == NULL) || (qout == NULL)) {
 252                 rc = -ENOMEM;
 253                 goto out_free;
 254         }
 255
 256         /* initialize diag input parameters */
 257         qin->qopcode = DCSS_FINDSEGA;
 258         qin->qoutptr = (unsigned long) qout;
 259         qin->qoutlen = sizeof(struct qout64);
 260         memcpy (qin->qname, seg->dcss_name, 8);
 261
 262         diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
 263
 264         if (diag_cc < 0) {
 265                 rc = diag_cc;
 266                 goto out_free;
 267         }
 268         if (diag_cc > 1) {
 269                 pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc);
 270                 rc = dcss_diag_translate_rc (vmrc);
 271                 goto out_free;
 272         }
 273
 274         /* Only old format of output area of Diagnose x'64' is supported,
 275            copy data for the new format. */
 276         if (segext_scode == DCSS_SEGEXT) {
 277                 struct qout64_old *qout_old;
 278                 qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
 279                 if (qout_old == NULL) {
 280                         rc = -ENOMEM;
 281                         goto out_free;
 282                 }
 283                 memcpy(qout_old, qout, sizeof(struct qout64_old));
 284                 qout->segstart = (unsigned long) qout_old->segstart;
 285                 qout->segend = (unsigned long) qout_old->segend;
 286                 qout->segcnt = qout_old->segcnt;
 287                 qout->segrcnt = qout_old->segrcnt;
 288
 289                 if (qout->segcnt > 6)
 290                         qout->segrcnt = 6;
 291                 for (i = 0; i < qout->segrcnt; i++) {
 292                         qout->range[i].start =
 293                                 (unsigned long) qout_old->range[i].start;
 294                         qout->range[i].end =
 295                                 (unsigned long) qout_old->range[i].end;
 296                 }
 297                 kfree(qout_old);
 298         }
 299         if (qout->segcnt > 6) {
 300                 rc = -EOPNOTSUPP;
 301                 goto out_free;
 302         }
 303
 304         if (qout->segcnt == 1) {
 305                 seg->vm_segtype = qout->range[0].start & 0xff;
 306         } else {
 307                 /* multi-part segment. only one type supported here:
 308                     - all parts are contiguous
 309                     - all parts are either EW or EN type
 310                     - maximum 6 parts allowed */
 311                 unsigned long start = qout->segstart >> PAGE_SHIFT;
 312                 for (i=0; i<qout->segcnt; i++) {
 313                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
 314                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
 315                                 rc = -EOPNOTSUPP;
 316                                 goto out_free;
 317                         }
 318                         if (start != qout->range[i].start >> PAGE_SHIFT) {
 319                                 rc = -EOPNOTSUPP;
 320                                 goto out_free;
 321                         }
 322                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
 323                 }
 324                 seg->vm_segtype = SEG_TYPE_EWEN;
 325         }
 326
 327         /* analyze diag output and update seg */
 328         seg->start_addr = qout->segstart;
 329         seg->end = qout->segend;
 330
 331         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
 332         seg->segcnt = qout->segcnt;
 333
 334         rc = 0;
 335
 336  out_free:
 337         kfree(qin);
 338         kfree(qout);
 339         return rc;
 340 }
 341
 342 /*
 343  * get info about a segment
 344  * possible return values:
 345  * -ENOSYS  : we are not running on VM
 346  * -EIO     : could not perform query diagnose
 347  * -ENOENT  : no such segment
 348  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 349  * -ENOMEM  : out of memory
 350  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 351  */
 352 int
 353 segment_type (char* name)
 354 {
 355         int rc;
 356         struct dcss_segment seg;
 357
 358         if (!MACHINE_IS_VM)
 359                 return -ENOSYS;
 360
 361         dcss_mkname(name, seg.dcss_name);
 362         rc = query_segment_type (&seg);
 363         if (rc < 0)
 364                 return rc;
 365         return seg.vm_segtype;
 366 }
 367
 368 /*
 369  * check if segment collides with other segments that are currently loaded
 370  * returns 1 if this is the case, 0 if no collision was found
 371  */
 372 static int
 373 segment_overlaps_others (struct dcss_segment *seg)
 374 {
 375         struct list_head *l;
 376         struct dcss_segment *tmp;
 377
 378         BUG_ON(!mutex_is_locked(&dcss_lock));
 379         list_for_each(l, &dcss_list) {
 380                 tmp = list_entry(l, struct dcss_segment, list);
 381                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
 382                         continue;
 383                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
 384                         continue;
 385                 if (seg == tmp)
 386                         continue;
 387                 return 1;
 388         }
 389         return 0;
 390 }
 391
 392 /*
 393  * real segment loading function, called from segment_load
 394  */
 395 static int
 396 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
 397 {
 398         unsigned long start_addr, end_addr, dummy;
 399         struct dcss_segment *seg;
 400         int rc, diag_cc;
 401
 402         start_addr = end_addr = 0;
 403         seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
 404         if (seg == NULL) {
 405                 rc = -ENOMEM;
 406                 goto out;
 407         }
 408         dcss_mkname (name, seg->dcss_name);
 409         rc = query_segment_type (seg);
 410         if (rc < 0)
 411                 goto out_free;
 412
 413         if (loadshr_scode == DCSS_LOADSHRX) {
 414                 if (segment_overlaps_others(seg)) {
 415                         rc = -EBUSY;
 416                         goto out_free;
 417                 }
 418         }
 419
 420         rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 421
 422         if (rc)
 423                 goto out_free;
 424
 425         seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 426         if (seg->res == NULL) {
 427                 rc = -ENOMEM;
 428                 goto out_shared;
 429         }
 430         seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 431         seg->res->start = seg->start_addr;
 432         seg->res->end = seg->end;
 433         memcpy(&seg->res_name, seg->dcss_name, 8);
 434         EBCASC(seg->res_name, 8);
 435         seg->res_name[8] = '\0';
 436         strncat(seg->res_name, " (DCSS)", 7);
 437         seg->res->name = seg->res_name;
 438         rc = seg->vm_segtype;
 439         if (rc == SEG_TYPE_SC ||
 440             ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
 441                 seg->res->flags |= IORESOURCE_READONLY;
 442         if (request_resource(&iomem_resource, seg->res)) {
 443                 rc = -EBUSY;
 444                 kfree(seg->res);
 445                 goto out_shared;
 446         }
 447
 448         if (do_nonshared)
 449                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 450                                 &start_addr, &end_addr);
 451         else
 452                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 453                                 &start_addr, &end_addr);
 454         if (diag_cc < 0) {
 455                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 456                                 &dummy, &dummy);
 457                 rc = diag_cc;
 458                 goto out_resource;
 459         }
 460         if (diag_cc > 1) {
 461                 pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr);
 462                 rc = dcss_diag_translate_rc(end_addr);
 463                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 464                                 &dummy, &dummy);
 465                 goto out_resource;
 466         }
 467         seg->start_addr = start_addr;
 468         seg->end = end_addr;
 469         seg->do_nonshared = do_nonshared;
 470         atomic_set(&seg->ref_count, 1);
 471         list_add(&seg->list, &dcss_list);
 472         *addr = seg->start_addr;
 473         *end  = seg->end;
 474         if (do_nonshared)
 475                 pr_info("DCSS %s of range %p to %p and type %s loaded as "
 476                         "exclusive-writable\n", name, (void*) seg->start_addr,
 477                         (void*) seg->end, segtype_string[seg->vm_segtype]);
 478         else {
 479                 pr_info("DCSS %s of range %p to %p and type %s loaded in "
 480                         "shared access mode\n", name, (void*) seg->start_addr,
 481                         (void*) seg->end, segtype_string[seg->vm_segtype]);
 482         }
 483         goto out;
 484  out_resource:
 485         release_resource(seg->res);
 486         kfree(seg->res);
 487  out_shared:
 488         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 489  out_free:
 490         kfree(seg);
 491  out:
 492         return rc;
 493 }
 494
 495 /*
 496  * this function loads a DCSS segment
 497  * name         : name of the DCSS
 498  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 499  *                1 indicates that the dcss should be exclusive for this linux image
 500  * addr         : will be filled with start address of the segment
 501  * end          : will be filled with end address of the segment
 502  * return values:
 503  * -ENOSYS  : we are not running on VM
 504  * -EIO     : could not perform query or load diagnose
 505  * -ENOENT  : no such segment
 506  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 507  * -ENOSPC  : segment cannot be used (overlaps with storage)
 508  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 509  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 510  * -EPERM   : segment is currently loaded with incompatible permissions
 511  * -ENOMEM  : out of memory
 512  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 513  */
 514 int
 515 segment_load (char *name, int do_nonshared, unsigned long *addr,
 516                 unsigned long *end)
 517 {
 518         struct dcss_segment *seg;
 519         int rc;
 520
 521         if (!MACHINE_IS_VM)
 522                 return -ENOSYS;
 523
 524         mutex_lock(&dcss_lock);
 525         seg = segment_by_name (name);
 526         if (seg == NULL)
 527                 rc = __segment_load (name, do_nonshared, addr, end);
 528         else {
 529                 if (do_nonshared == seg->do_nonshared) {
 530                         atomic_inc(&seg->ref_count);
 531                         *addr = seg->start_addr;
 532                         *end  = seg->end;
 533                         rc    = seg->vm_segtype;
 534                 } else {
 535                         *addr = *end = 0;
 536                         rc    = -EPERM;
 537                 }
 538         }
 539         mutex_unlock(&dcss_lock);
 540         return rc;
 541 }
 542
 543 /*
 544  * this function modifies the shared state of a DCSS segment. note that
 545  * name         : name of the DCSS
 546  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 547  *                1 indicates that the dcss should be exclusive for this linux image
 548  * return values:
 549  * -EIO     : could not perform load diagnose (segment gone!)
 550  * -ENOENT  : no such segment (segment gone!)
 551  * -EAGAIN  : segment is in use by other exploiters, try later
 552  * -EINVAL  : no segment with the given name is currently loaded - name invalid
 553  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 554  * 0        : operation succeeded
 555  */
 556 int
 557 segment_modify_shared (char *name, int do_nonshared)
 558 {
 559         struct dcss_segment *seg;
 560         unsigned long start_addr, end_addr, dummy;
 561         int rc, diag_cc;
 562
 563         start_addr = end_addr = 0;
 564         mutex_lock(&dcss_lock);
 565         seg = segment_by_name (name);
 566         if (seg == NULL) {
 567                 rc = -EINVAL;
 568                 goto out_unlock;
 569         }
 570         if (do_nonshared == seg->do_nonshared) {
 571                 pr_info("DCSS %s is already in the requested access "
 572                         "mode\n", name);
 573                 rc = 0;
 574                 goto out_unlock;
 575         }
 576         if (atomic_read (&seg->ref_count) != 1) {
 577                 pr_warn("DCSS %s is in use and cannot be reloaded\n", name);
 578                 rc = -EAGAIN;
 579                 goto out_unlock;
 580         }
 581         release_resource(seg->res);
 582         if (do_nonshared)
 583                 seg->res->flags &= ~IORESOURCE_READONLY;
 584         else
 585                 if (seg->vm_segtype == SEG_TYPE_SR ||
 586                     seg->vm_segtype == SEG_TYPE_ER)
 587                         seg->res->flags |= IORESOURCE_READONLY;
 588
 589         if (request_resource(&iomem_resource, seg->res)) {
 590                 pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n",
 591                         name);
 592                 rc = -EBUSY;
 593                 kfree(seg->res);
 594                 goto out_del_mem;
 595         }
 596
 597         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 598         if (do_nonshared)
 599                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 600                                 &start_addr, &end_addr);
 601         else
 602                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 603                                 &start_addr, &end_addr);
 604         if (diag_cc < 0) {
 605                 rc = diag_cc;
 606                 goto out_del_res;
 607         }
 608         if (diag_cc > 1) {
 609                 pr_warn("Reloading DCSS %s failed with rc=%ld\n",
 610                         name, end_addr);
 611                 rc = dcss_diag_translate_rc(end_addr);
 612                 goto out_del_res;
 613         }
 614         seg->start_addr = start_addr;
 615         seg->end = end_addr;
 616         seg->do_nonshared = do_nonshared;
 617         rc = 0;
 618         goto out_unlock;
 619  out_del_res:
 620         release_resource(seg->res);
 621         kfree(seg->res);
 622  out_del_mem:
 623         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 624         list_del(&seg->list);
 625         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 626         kfree(seg);
 627  out_unlock:
 628         mutex_unlock(&dcss_lock);
 629         return rc;
 630 }
 631
 632 /*
 633  * Decrease the use count of a DCSS segment and remove
 634  * it from the address space if nobody is using it
 635  * any longer.
 636  */
 637 void
 638 segment_unload(char *name)
 639 {
 640         unsigned long dummy;
 641         struct dcss_segment *seg;
 642
 643         if (!MACHINE_IS_VM)
 644                 return;
 645
 646         mutex_lock(&dcss_lock);
 647         seg = segment_by_name (name);
 648         if (seg == NULL) {
 649                 pr_err("Unloading unknown DCSS %s failed\n", name);
 650                 goto out_unlock;
 651         }
 652         if (atomic_dec_return(&seg->ref_count) != 0)
 653                 goto out_unlock;
 654         release_resource(seg->res);
 655         kfree(seg->res);
 656         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 657         list_del(&seg->list);
 658         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 659         kfree(seg);
 660 out_unlock:
 661         mutex_unlock(&dcss_lock);
 662 }
 663
 664 /*
 665  * save segment content permanently
 666  */
 667 void
 668 segment_save(char *name)
 669 {
 670         struct dcss_segment *seg;
 671         char cmd1[160];
 672         char cmd2[80];
 673         int i, response;
 674
 675         if (!MACHINE_IS_VM)
 676                 return;
 677
 678         mutex_lock(&dcss_lock);
 679         seg = segment_by_name (name);
 680
 681         if (seg == NULL) {
 682                 pr_err("Saving unknown DCSS %s failed\n", name);
 683                 goto out;
 684         }
 685
 686         sprintf(cmd1, "DEFSEG %s", name);
 687         for (i=0; i<seg->segcnt; i++) {
 688                 sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
 689                         seg->range[i].start >> PAGE_SHIFT,
 690                         seg->range[i].end >> PAGE_SHIFT,
 691                         segtype_string[seg->range[i].start & 0xff]);
 692         }
 693         sprintf(cmd2, "SAVESEG %s", name);
 694         response = 0;
 695         cpcmd(cmd1, NULL, 0, &response);
 696         if (response) {
 697                 pr_err("Saving a DCSS failed with DEFSEG response code "
 698                        "%i\n", response);
 699                 goto out;
 700         }
 701         cpcmd(cmd2, NULL, 0, &response);
 702         if (response) {
 703                 pr_err("Saving a DCSS failed with SAVESEG response code "
 704                        "%i\n", response);
 705                 goto out;
 706         }
 707 out:
 708         mutex_unlock(&dcss_lock);
 709 }
 710
 711 /*
 712  * print appropriate error message for segment_load()/segment_type()
 713  * return code
 714  */
 715 void segment_warning(int rc, char *seg_name)
 716 {
 717         switch (rc) {
 718         case -ENOENT:
 719                 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
 720                 break;
 721         case -ENOSYS:
 722                 pr_err("DCSS %s cannot be loaded or queried without "
 723                        "z/VM\n", seg_name);
 724                 break;
 725         case -EIO:
 726                 pr_err("Loading or querying DCSS %s resulted in a "
 727                        "hardware error\n", seg_name);
 728                 break;
 729         case -EOPNOTSUPP:
 730                 pr_err("DCSS %s has multiple page ranges and cannot be "
 731                        "loaded or queried\n", seg_name);
 732                 break;
 733         case -ENOSPC:
 734                 pr_err("DCSS %s overlaps with used storage and cannot "
 735                        "be loaded\n", seg_name);
 736                 break;
 737         case -EBUSY:
 738                 pr_err("%s needs used memory resources and cannot be "
 739                        "loaded or queried\n", seg_name);
 740                 break;
 741         case -EPERM:
 742                 pr_err("DCSS %s is already loaded in a different access "
 743                        "mode\n", seg_name);
 744                 break;
 745         case -ENOMEM:
 746                 pr_err("There is not enough memory to load or query "
 747                        "DCSS %s\n", seg_name);
 748                 break;
 749         case -ERANGE:
 750                 pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
 751                        "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
 752                 break;
 753         default:
 754                 break;
 755         }
 756 }
 757
 758 EXPORT_SYMBOL(segment_load);
 759 EXPORT_SYMBOL(segment_unload);
 760 EXPORT_SYMBOL(segment_save);
 761 EXPORT_SYMBOL(segment_type);
 762 EXPORT_SYMBOL(segment_modify_shared);
 763 EXPORT_SYMBOL(segment_warning);