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_warning("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_warning("Loading DCSS %s failed with rc=%ld\n", name,
 461                            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_warning("DCSS %s is in use and cannot be reloaded\n",
 578                            name);
 579                 rc = -EAGAIN;
 580                 goto out_unlock;
 581         }
 582         release_resource(seg->res);
 583         if (do_nonshared)
 584                 seg->res->flags &= ~IORESOURCE_READONLY;
 585         else
 586                 if (seg->vm_segtype == SEG_TYPE_SR ||
 587                     seg->vm_segtype == SEG_TYPE_ER)
 588                         seg->res->flags |= IORESOURCE_READONLY;
 589
 590         if (request_resource(&iomem_resource, seg->res)) {
 591                 pr_warning("DCSS %s overlaps with used memory resources "
 592                            "and cannot be reloaded\n", name);
 593                 rc = -EBUSY;
 594                 kfree(seg->res);
 595                 goto out_del_mem;
 596         }
 597
 598         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 599         if (do_nonshared)
 600                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 601                                 &start_addr, &end_addr);
 602         else
 603                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 604                                 &start_addr, &end_addr);
 605         if (diag_cc < 0) {
 606                 rc = diag_cc;
 607                 goto out_del_res;
 608         }
 609         if (diag_cc > 1) {
 610                 pr_warning("Reloading DCSS %s failed with rc=%ld\n", name,
 611                            end_addr);
 612                 rc = dcss_diag_translate_rc(end_addr);
 613                 goto out_del_res;
 614         }
 615         seg->start_addr = start_addr;
 616         seg->end = end_addr;
 617         seg->do_nonshared = do_nonshared;
 618         rc = 0;
 619         goto out_unlock;
 620  out_del_res:
 621         release_resource(seg->res);
 622         kfree(seg->res);
 623  out_del_mem:
 624         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 625         list_del(&seg->list);
 626         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 627         kfree(seg);
 628  out_unlock:
 629         mutex_unlock(&dcss_lock);
 630         return rc;
 631 }
 632
 633 /*
 634  * Decrease the use count of a DCSS segment and remove
 635  * it from the address space if nobody is using it
 636  * any longer.
 637  */
 638 void
 639 segment_unload(char *name)
 640 {
 641         unsigned long dummy;
 642         struct dcss_segment *seg;
 643
 644         if (!MACHINE_IS_VM)
 645                 return;
 646
 647         mutex_lock(&dcss_lock);
 648         seg = segment_by_name (name);
 649         if (seg == NULL) {
 650                 pr_err("Unloading unknown DCSS %s failed\n", name);
 651                 goto out_unlock;
 652         }
 653         if (atomic_dec_return(&seg->ref_count) != 0)
 654                 goto out_unlock;
 655         release_resource(seg->res);
 656         kfree(seg->res);
 657         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 658         list_del(&seg->list);
 659         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 660         kfree(seg);
 661 out_unlock:
 662         mutex_unlock(&dcss_lock);
 663 }
 664
 665 /*
 666  * save segment content permanently
 667  */
 668 void
 669 segment_save(char *name)
 670 {
 671         struct dcss_segment *seg;
 672         char cmd1[160];
 673         char cmd2[80];
 674         int i, response;
 675
 676         if (!MACHINE_IS_VM)
 677                 return;
 678
 679         mutex_lock(&dcss_lock);
 680         seg = segment_by_name (name);
 681
 682         if (seg == NULL) {
 683                 pr_err("Saving unknown DCSS %s failed\n", name);
 684                 goto out;
 685         }
 686
 687         sprintf(cmd1, "DEFSEG %s", name);
 688         for (i=0; i<seg->segcnt; i++) {
 689                 sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
 690                         seg->range[i].start >> PAGE_SHIFT,
 691                         seg->range[i].end >> PAGE_SHIFT,
 692                         segtype_string[seg->range[i].start & 0xff]);
 693         }
 694         sprintf(cmd2, "SAVESEG %s", name);
 695         response = 0;
 696         cpcmd(cmd1, NULL, 0, &response);
 697         if (response) {
 698                 pr_err("Saving a DCSS failed with DEFSEG response code "
 699                        "%i\n", response);
 700                 goto out;
 701         }
 702         cpcmd(cmd2, NULL, 0, &response);
 703         if (response) {
 704                 pr_err("Saving a DCSS failed with SAVESEG response code "
 705                        "%i\n", response);
 706                 goto out;
 707         }
 708 out:
 709         mutex_unlock(&dcss_lock);
 710 }
 711
 712 /*
 713  * print appropriate error message for segment_load()/segment_type()
 714  * return code
 715  */
 716 void segment_warning(int rc, char *seg_name)
 717 {
 718         switch (rc) {
 719         case -ENOENT:
 720                 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
 721                 break;
 722         case -ENOSYS:
 723                 pr_err("DCSS %s cannot be loaded or queried without "
 724                        "z/VM\n", seg_name);
 725                 break;
 726         case -EIO:
 727                 pr_err("Loading or querying DCSS %s resulted in a "
 728                        "hardware error\n", seg_name);
 729                 break;
 730         case -EOPNOTSUPP:
 731                 pr_err("DCSS %s has multiple page ranges and cannot be "
 732                        "loaded or queried\n", seg_name);
 733                 break;
 734         case -ENOSPC:
 735                 pr_err("DCSS %s overlaps with used storage and cannot "
 736                        "be loaded\n", seg_name);
 737                 break;
 738         case -EBUSY:
 739                 pr_err("%s needs used memory resources and cannot be "
 740                        "loaded or queried\n", seg_name);
 741                 break;
 742         case -EPERM:
 743                 pr_err("DCSS %s is already loaded in a different access "
 744                        "mode\n", seg_name);
 745                 break;
 746         case -ENOMEM:
 747                 pr_err("There is not enough memory to load or query "
 748                        "DCSS %s\n", seg_name);
 749                 break;
 750         case -ERANGE:
 751                 pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
 752                        "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
 753                 break;
 754         default:
 755                 break;
 756         }
 757 }
 758
 759 EXPORT_SYMBOL(segment_load);
 760 EXPORT_SYMBOL(segment_unload);
 761 EXPORT_SYMBOL(segment_save);
 762 EXPORT_SYMBOL(segment_type);
 763 EXPORT_SYMBOL(segment_modify_shared);
 764 EXPORT_SYMBOL(segment_warning);