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