kernel/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/page.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/errno.h>
  25 #include <asm/extmem.h>
  26 #include <asm/cpcmd.h>
  27 #include <asm/setup.h>
  28
  29 #define DCSS_LOADSHR    0x00
  30 #define DCSS_LOADNSR    0x04
  31 #define DCSS_PURGESEG   0x08
  32 #define DCSS_FINDSEG    0x0c
  33 #define DCSS_LOADNOLY   0x10
  34 #define DCSS_SEGEXT     0x18
  35 #define DCSS_LOADSHRX   0x20
  36 #define DCSS_LOADNSRX   0x24
  37 #define DCSS_FINDSEGX   0x2c
  38 #define DCSS_SEGEXTX    0x38
  39 #define DCSS_FINDSEGA   0x0c
  40
  41 struct qrange {
  42         unsigned long  start; /* last byte type */
  43         unsigned long  end;   /* last byte reserved */
  44 };
  45
  46 struct qout64 {
  47         unsigned long segstart;
  48         unsigned long segend;
  49         int segcnt;
  50         int segrcnt;
  51         struct qrange range[6];
  52 };
  53
  54 struct qrange_old {
  55         unsigned int start; /* last byte type */
  56         unsigned int end;   /* last byte reserved */
  57 };
  58
  59 /* output area format for the Diag x'64' old subcode x'18' */
  60 struct qout64_old {
  61         int segstart;
  62         int segend;
  63         int segcnt;
  64         int segrcnt;
  65         struct qrange_old range[6];
  66 };
  67
  68 struct qin64 {
  69         char qopcode;
  70         char rsrv1[3];
  71         char qrcode;
  72         char rsrv2[3];
  73         char qname[8];
  74         unsigned int qoutptr;
  75         short int qoutlen;
  76 };
  77
  78 struct dcss_segment {
  79         struct list_head list;
  80         char dcss_name[8];
  81         char res_name[15];
  82         unsigned long start_addr;
  83         unsigned long end;
  84         atomic_t ref_count;
  85         int do_nonshared;
  86         unsigned int vm_segtype;
  87         struct qrange range[6];
  88         int segcnt;
  89         struct resource *res;
  90 };
  91
  92 static DEFINE_MUTEX(dcss_lock);
  93 static LIST_HEAD(dcss_list);
  94 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
  95                                         "EW/EN-MIXED" };
  96 static int loadshr_scode, loadnsr_scode, findseg_scode;
  97 static int segext_scode, purgeseg_scode;
  98 static int scode_set;
  99
 100 /* set correct Diag x'64' subcodes. */
 101 static int
 102 dcss_set_subcodes(void)
 103 {
 104         char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
 105         unsigned long rx, ry;
 106         int rc;
 107
 108         if (name == NULL)
 109                 return -ENOMEM;
 110
 111         rx = (unsigned long) name;
 112         ry = DCSS_FINDSEGX;
 113
 114         strcpy(name, "dummy");
 115         asm volatile(
 116                 "       diag    %0,%1,0x64\n"
 117                 "0:     ipm     %2\n"
 118                 "       srl     %2,28\n"
 119                 "       j       2f\n"
 120                 "1:     la      %2,3\n"
 121                 "2:\n"
 122                 EX_TABLE(0b, 1b)
 123                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 124
 125         kfree(name);
 126         /* Diag x'64' new subcodes are supported, set to new subcodes */
 127         if (rc != 3) {
 128                 loadshr_scode = DCSS_LOADSHRX;
 129                 loadnsr_scode = DCSS_LOADNSRX;
 130                 purgeseg_scode = DCSS_PURGESEG;
 131                 findseg_scode = DCSS_FINDSEGX;
 132                 segext_scode = DCSS_SEGEXTX;
 133                 return 0;
 134         }
 135         /* Diag x'64' new subcodes are not supported, set to old subcodes */
 136         loadshr_scode = DCSS_LOADNOLY;
 137         loadnsr_scode = DCSS_LOADNSR;
 138         purgeseg_scode = DCSS_PURGESEG;
 139         findseg_scode = DCSS_FINDSEG;
 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         if (*func > DCSS_SEGEXT)
 209                 asm volatile(
 210                         "       diag    %0,%1,0x64\n"
 211                         "       ipm     %2\n"
 212                         "       srl     %2,28\n"
 213                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 214         /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
 215         else
 216                 asm volatile(
 217                         "       sam31\n"
 218                         "       diag    %0,%1,0x64\n"
 219                         "       sam64\n"
 220                         "       ipm     %2\n"
 221                         "       srl     %2,28\n"
 222                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 223         *ret1 = rx;
 224         *ret2 = ry;
 225         return rc;
 226 }
 227
 228 static inline int
 229 dcss_diag_translate_rc (int vm_rc) {
 230         if (vm_rc == 44)
 231                 return -ENOENT;
 232         return -EIO;
 233 }
 234
 235
 236 /* do a diag to get info about a segment.
 237  * fills start_address, end and vm_segtype fields
 238  */
 239 static int
 240 query_segment_type (struct dcss_segment *seg)
 241 {
 242         unsigned long dummy, vmrc;
 243         int diag_cc, rc, i;
 244         struct qout64 *qout;
 245         struct qin64 *qin;
 246
 247         qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
 248         qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
 249         if ((qin == NULL) || (qout == NULL)) {
 250                 rc = -ENOMEM;
 251                 goto out_free;
 252         }
 253
 254         /* initialize diag input parameters */
 255         qin->qopcode = DCSS_FINDSEGA;
 256         qin->qoutptr = (unsigned long) qout;
 257         qin->qoutlen = sizeof(struct qout64);
 258         memcpy (qin->qname, seg->dcss_name, 8);
 259
 260         diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
 261
 262         if (diag_cc < 0) {
 263                 rc = diag_cc;
 264                 goto out_free;
 265         }
 266         if (diag_cc > 1) {
 267                 pr_warning("Querying a DCSS type failed with rc=%ld\n", vmrc);
 268                 rc = dcss_diag_translate_rc (vmrc);
 269                 goto out_free;
 270         }
 271
 272         /* Only old format of output area of Diagnose x'64' is supported,
 273            copy data for the new format. */
 274         if (segext_scode == DCSS_SEGEXT) {
 275                 struct qout64_old *qout_old;
 276                 qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
 277                 if (qout_old == NULL) {
 278                         rc = -ENOMEM;
 279                         goto out_free;
 280                 }
 281                 memcpy(qout_old, qout, sizeof(struct qout64_old));
 282                 qout->segstart = (unsigned long) qout_old->segstart;
 283                 qout->segend = (unsigned long) qout_old->segend;
 284                 qout->segcnt = qout_old->segcnt;
 285                 qout->segrcnt = qout_old->segrcnt;
 286
 287                 if (qout->segcnt > 6)
 288                         qout->segrcnt = 6;
 289                 for (i = 0; i < qout->segrcnt; i++) {
 290                         qout->range[i].start =
 291                                 (unsigned long) qout_old->range[i].start;
 292                         qout->range[i].end =
 293                                 (unsigned long) qout_old->range[i].end;
 294                 }
 295                 kfree(qout_old);
 296         }
 297         if (qout->segcnt > 6) {
 298                 rc = -EOPNOTSUPP;
 299                 goto out_free;
 300         }
 301
 302         if (qout->segcnt == 1) {
 303                 seg->vm_segtype = qout->range[0].start & 0xff;
 304         } else {
 305                 /* multi-part segment. only one type supported here:
 306                     - all parts are contiguous
 307                     - all parts are either EW or EN type
 308                     - maximum 6 parts allowed */
 309                 unsigned long start = qout->segstart >> PAGE_SHIFT;
 310                 for (i=0; i<qout->segcnt; i++) {
 311                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
 312                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
 313                                 rc = -EOPNOTSUPP;
 314                                 goto out_free;
 315                         }
 316                         if (start != qout->range[i].start >> PAGE_SHIFT) {
 317                                 rc = -EOPNOTSUPP;
 318                                 goto out_free;
 319                         }
 320                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
 321                 }
 322                 seg->vm_segtype = SEG_TYPE_EWEN;
 323         }
 324
 325         /* analyze diag output and update seg */
 326         seg->start_addr = qout->segstart;
 327         seg->end = qout->segend;
 328
 329         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
 330         seg->segcnt = qout->segcnt;
 331
 332         rc = 0;
 333
 334  out_free:
 335         kfree(qin);
 336         kfree(qout);
 337         return rc;
 338 }
 339
 340 /*
 341  * get info about a segment
 342  * possible return values:
 343  * -ENOSYS  : we are not running on VM
 344  * -EIO     : could not perform query diagnose
 345  * -ENOENT  : no such segment
 346  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 347  * -ENOMEM  : out of memory
 348  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 349  */
 350 int
 351 segment_type (char* name)
 352 {
 353         int rc;
 354         struct dcss_segment seg;
 355
 356         if (!MACHINE_IS_VM)
 357                 return -ENOSYS;
 358
 359         dcss_mkname(name, seg.dcss_name);
 360         rc = query_segment_type (&seg);
 361         if (rc < 0)
 362                 return rc;
 363         return seg.vm_segtype;
 364 }
 365
 366 /*
 367  * check if segment collides with other segments that are currently loaded
 368  * returns 1 if this is the case, 0 if no collision was found
 369  */
 370 static int
 371 segment_overlaps_others (struct dcss_segment *seg)
 372 {
 373         struct list_head *l;
 374         struct dcss_segment *tmp;
 375
 376         BUG_ON(!mutex_is_locked(&dcss_lock));
 377         list_for_each(l, &dcss_list) {
 378                 tmp = list_entry(l, struct dcss_segment, list);
 379                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
 380                         continue;
 381                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
 382                         continue;
 383                 if (seg == tmp)
 384                         continue;
 385                 return 1;
 386         }
 387         return 0;
 388 }
 389
 390 /*
 391  * real segment loading function, called from segment_load
 392  */
 393 static int
 394 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
 395 {
 396         unsigned long start_addr, end_addr, dummy;
 397         struct dcss_segment *seg;
 398         int rc, diag_cc;
 399
 400         start_addr = end_addr = 0;
 401         seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
 402         if (seg == NULL) {
 403                 rc = -ENOMEM;
 404                 goto out;
 405         }
 406         dcss_mkname (name, seg->dcss_name);
 407         rc = query_segment_type (seg);
 408         if (rc < 0)
 409                 goto out_free;
 410
 411         if (loadshr_scode == DCSS_LOADSHRX) {
 412                 if (segment_overlaps_others(seg)) {
 413                         rc = -EBUSY;
 414                         goto out_free;
 415                 }
 416         }
 417
 418         rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 419
 420         if (rc)
 421                 goto out_free;
 422
 423         seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 424         if (seg->res == NULL) {
 425                 rc = -ENOMEM;
 426                 goto out_shared;
 427         }
 428         seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 429         seg->res->start = seg->start_addr;
 430         seg->res->end = seg->end;
 431         memcpy(&seg->res_name, seg->dcss_name, 8);
 432         EBCASC(seg->res_name, 8);
 433         seg->res_name[8] = '\0';
 434         strncat(seg->res_name, " (DCSS)", 7);
 435         seg->res->name = seg->res_name;
 436         rc = seg->vm_segtype;
 437         if (rc == SEG_TYPE_SC ||
 438             ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
 439                 seg->res->flags |= IORESOURCE_READONLY;
 440         if (request_resource(&iomem_resource, seg->res)) {
 441                 rc = -EBUSY;
 442                 kfree(seg->res);
 443                 goto out_shared;
 444         }
 445
 446         if (do_nonshared)
 447                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 448                                 &start_addr, &end_addr);
 449         else
 450                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 451                                 &start_addr, &end_addr);
 452         if (diag_cc < 0) {
 453                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 454                                 &dummy, &dummy);
 455                 rc = diag_cc;
 456                 goto out_resource;
 457         }
 458         if (diag_cc > 1) {
 459                 pr_warning("Loading DCSS %s failed with rc=%ld\n", name,
 460                            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_warning("DCSS %s is in use and cannot be reloaded\n",
 577                            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_warning("DCSS %s overlaps with used memory resources "
 591                            "and cannot be reloaded\n", 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_warning("Reloading DCSS %s failed with rc=%ld\n", name,
 610                            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);