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 #ifdef CONFIG_64BIT
  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 #endif
  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, findseg_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 #ifdef CONFIG_64BIT
 107         char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
 108         unsigned long rx, ry;
 109         int rc;
 110
 111         if (name == NULL)
 112                 return -ENOMEM;
 113
 114         rx = (unsigned long) name;
 115         ry = DCSS_FINDSEGX;
 116
 117         strcpy(name, "dummy");
 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");
 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                 findseg_scode = DCSS_FINDSEGX;
 135                 segext_scode = DCSS_SEGEXTX;
 136                 return 0;
 137         }
 138 #endif
 139         /* Diag x'64' new subcodes are not supported, set to old subcodes */
 140         loadshr_scode = DCSS_LOADNOLY;
 141         loadnsr_scode = DCSS_LOADNSR;
 142         purgeseg_scode = DCSS_PURGESEG;
 143         findseg_scode = DCSS_FINDSEG;
 144         segext_scode = DCSS_SEGEXT;
 145         return 0;
 146 }
 147
 148 /*
 149  * Create the 8 bytes, ebcdic VM segment name from
 150  * an ascii name.
 151  */
 152 static void
 153 dcss_mkname(char *name, char *dcss_name)
 154 {
 155         int i;
 156
 157         for (i = 0; i < 8; i++) {
 158                 if (name[i] == '\0')
 159                         break;
 160                 dcss_name[i] = toupper(name[i]);
 161         };
 162         for (; i < 8; i++)
 163                 dcss_name[i] = ' ';
 164         ASCEBC(dcss_name, 8);
 165 }
 166
 167
 168 /*
 169  * search all segments in dcss_list, and return the one
 170  * namend *name. If not found, return NULL.
 171  */
 172 static struct dcss_segment *
 173 segment_by_name (char *name)
 174 {
 175         char dcss_name[9];
 176         struct list_head *l;
 177         struct dcss_segment *tmp, *retval = NULL;
 178
 179         BUG_ON(!mutex_is_locked(&dcss_lock));
 180         dcss_mkname (name, dcss_name);
 181         list_for_each (l, &dcss_list) {
 182                 tmp = list_entry (l, struct dcss_segment, list);
 183                 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
 184                         retval = tmp;
 185                         break;
 186                 }
 187         }
 188         return retval;
 189 }
 190
 191
 192 /*
 193  * Perform a function on a dcss segment.
 194  */
 195 static inline int
 196 dcss_diag(int *func, void *parameter,
 197            unsigned long *ret1, unsigned long *ret2)
 198 {
 199         unsigned long rx, ry;
 200         int rc;
 201
 202         if (scode_set == 0) {
 203                 rc = dcss_set_subcodes();
 204                 if (rc < 0)
 205                         return rc;
 206                 scode_set = 1;
 207         }
 208         rx = (unsigned long) parameter;
 209         ry = (unsigned long) *func;
 210
 211 #ifdef CONFIG_64BIT
 212         /* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
 213         if (*func > DCSS_SEGEXT)
 214                 asm volatile(
 215                         "       diag    %0,%1,0x64\n"
 216                         "       ipm     %2\n"
 217                         "       srl     %2,28\n"
 218                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 219         /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
 220         else
 221                 asm volatile(
 222                         "       sam31\n"
 223                         "       diag    %0,%1,0x64\n"
 224                         "       sam64\n"
 225                         "       ipm     %2\n"
 226                         "       srl     %2,28\n"
 227                         : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 228 #else
 229         asm volatile(
 230                 "       diag    %0,%1,0x64\n"
 231                 "       ipm     %2\n"
 232                 "       srl     %2,28\n"
 233                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 234 #endif
 235         *ret1 = rx;
 236         *ret2 = ry;
 237         return rc;
 238 }
 239
 240 static inline int
 241 dcss_diag_translate_rc (int vm_rc) {
 242         if (vm_rc == 44)
 243                 return -ENOENT;
 244         return -EIO;
 245 }
 246
 247
 248 /* do a diag to get info about a segment.
 249  * fills start_address, end and vm_segtype fields
 250  */
 251 static int
 252 query_segment_type (struct dcss_segment *seg)
 253 {
 254         unsigned long dummy, vmrc;
 255         int diag_cc, rc, i;
 256         struct qout64 *qout;
 257         struct qin64 *qin;
 258
 259         qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
 260         qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
 261         if ((qin == NULL) || (qout == NULL)) {
 262                 rc = -ENOMEM;
 263                 goto out_free;
 264         }
 265
 266         /* initialize diag input parameters */
 267         qin->qopcode = DCSS_FINDSEGA;
 268         qin->qoutptr = (unsigned long) qout;
 269         qin->qoutlen = sizeof(struct qout64);
 270         memcpy (qin->qname, seg->dcss_name, 8);
 271
 272         diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
 273
 274         if (diag_cc < 0) {
 275                 rc = diag_cc;
 276                 goto out_free;
 277         }
 278         if (diag_cc > 1) {
 279                 pr_warning("Querying a DCSS type failed with rc=%ld\n", vmrc);
 280                 rc = dcss_diag_translate_rc (vmrc);
 281                 goto out_free;
 282         }
 283
 284 #ifdef CONFIG_64BIT
 285         /* Only old format of output area of Diagnose x'64' is supported,
 286            copy data for the new format. */
 287         if (segext_scode == DCSS_SEGEXT) {
 288                 struct qout64_old *qout_old;
 289                 qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
 290                 if (qout_old == NULL) {
 291                         rc = -ENOMEM;
 292                         goto out_free;
 293                 }
 294                 memcpy(qout_old, qout, sizeof(struct qout64_old));
 295                 qout->segstart = (unsigned long) qout_old->segstart;
 296                 qout->segend = (unsigned long) qout_old->segend;
 297                 qout->segcnt = qout_old->segcnt;
 298                 qout->segrcnt = qout_old->segrcnt;
 299
 300                 if (qout->segcnt > 6)
 301                         qout->segrcnt = 6;
 302                 for (i = 0; i < qout->segrcnt; i++) {
 303                         qout->range[i].start =
 304                                 (unsigned long) qout_old->range[i].start;
 305                         qout->range[i].end =
 306                                 (unsigned long) qout_old->range[i].end;
 307                 }
 308                 kfree(qout_old);
 309         }
 310 #endif
 311         if (qout->segcnt > 6) {
 312                 rc = -EOPNOTSUPP;
 313                 goto out_free;
 314         }
 315
 316         if (qout->segcnt == 1) {
 317                 seg->vm_segtype = qout->range[0].start & 0xff;
 318         } else {
 319                 /* multi-part segment. only one type supported here:
 320                     - all parts are contiguous
 321                     - all parts are either EW or EN type
 322                     - maximum 6 parts allowed */
 323                 unsigned long start = qout->segstart >> PAGE_SHIFT;
 324                 for (i=0; i<qout->segcnt; i++) {
 325                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
 326                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
 327                                 rc = -EOPNOTSUPP;
 328                                 goto out_free;
 329                         }
 330                         if (start != qout->range[i].start >> PAGE_SHIFT) {
 331                                 rc = -EOPNOTSUPP;
 332                                 goto out_free;
 333                         }
 334                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
 335                 }
 336                 seg->vm_segtype = SEG_TYPE_EWEN;
 337         }
 338
 339         /* analyze diag output and update seg */
 340         seg->start_addr = qout->segstart;
 341         seg->end = qout->segend;
 342
 343         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
 344         seg->segcnt = qout->segcnt;
 345
 346         rc = 0;
 347
 348  out_free:
 349         kfree(qin);
 350         kfree(qout);
 351         return rc;
 352 }
 353
 354 /*
 355  * get info about a segment
 356  * possible return values:
 357  * -ENOSYS  : we are not running on VM
 358  * -EIO     : could not perform query diagnose
 359  * -ENOENT  : no such segment
 360  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 361  * -ENOMEM  : out of memory
 362  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 363  */
 364 int
 365 segment_type (char* name)
 366 {
 367         int rc;
 368         struct dcss_segment seg;
 369
 370         if (!MACHINE_IS_VM)
 371                 return -ENOSYS;
 372
 373         dcss_mkname(name, seg.dcss_name);
 374         rc = query_segment_type (&seg);
 375         if (rc < 0)
 376                 return rc;
 377         return seg.vm_segtype;
 378 }
 379
 380 /*
 381  * check if segment collides with other segments that are currently loaded
 382  * returns 1 if this is the case, 0 if no collision was found
 383  */
 384 static int
 385 segment_overlaps_others (struct dcss_segment *seg)
 386 {
 387         struct list_head *l;
 388         struct dcss_segment *tmp;
 389
 390         BUG_ON(!mutex_is_locked(&dcss_lock));
 391         list_for_each(l, &dcss_list) {
 392                 tmp = list_entry(l, struct dcss_segment, list);
 393                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
 394                         continue;
 395                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
 396                         continue;
 397                 if (seg == tmp)
 398                         continue;
 399                 return 1;
 400         }
 401         return 0;
 402 }
 403
 404 /*
 405  * real segment loading function, called from segment_load
 406  */
 407 static int
 408 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
 409 {
 410         unsigned long start_addr, end_addr, dummy;
 411         struct dcss_segment *seg;
 412         int rc, diag_cc;
 413
 414         start_addr = end_addr = 0;
 415         seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
 416         if (seg == NULL) {
 417                 rc = -ENOMEM;
 418                 goto out;
 419         }
 420         dcss_mkname (name, seg->dcss_name);
 421         rc = query_segment_type (seg);
 422         if (rc < 0)
 423                 goto out_free;
 424
 425         if (loadshr_scode == DCSS_LOADSHRX) {
 426                 if (segment_overlaps_others(seg)) {
 427                         rc = -EBUSY;
 428                         goto out_free;
 429                 }
 430         }
 431
 432         rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 433
 434         if (rc)
 435                 goto out_free;
 436
 437         seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 438         if (seg->res == NULL) {
 439                 rc = -ENOMEM;
 440                 goto out_shared;
 441         }
 442         seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 443         seg->res->start = seg->start_addr;
 444         seg->res->end = seg->end;
 445         memcpy(&seg->res_name, seg->dcss_name, 8);
 446         EBCASC(seg->res_name, 8);
 447         seg->res_name[8] = '\0';
 448         strncat(seg->res_name, " (DCSS)", 7);
 449         seg->res->name = seg->res_name;
 450         rc = seg->vm_segtype;
 451         if (rc == SEG_TYPE_SC ||
 452             ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
 453                 seg->res->flags |= IORESOURCE_READONLY;
 454         if (request_resource(&iomem_resource, seg->res)) {
 455                 rc = -EBUSY;
 456                 kfree(seg->res);
 457                 goto out_shared;
 458         }
 459
 460         if (do_nonshared)
 461                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 462                                 &start_addr, &end_addr);
 463         else
 464                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 465                                 &start_addr, &end_addr);
 466         if (diag_cc < 0) {
 467                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 468                                 &dummy, &dummy);
 469                 rc = diag_cc;
 470                 goto out_resource;
 471         }
 472         if (diag_cc > 1) {
 473                 pr_warning("Loading DCSS %s failed with rc=%ld\n", name,
 474                            end_addr);
 475                 rc = dcss_diag_translate_rc(end_addr);
 476                 dcss_diag(&purgeseg_scode, seg->dcss_name,
 477                                 &dummy, &dummy);
 478                 goto out_resource;
 479         }
 480         seg->start_addr = start_addr;
 481         seg->end = end_addr;
 482         seg->do_nonshared = do_nonshared;
 483         atomic_set(&seg->ref_count, 1);
 484         list_add(&seg->list, &dcss_list);
 485         *addr = seg->start_addr;
 486         *end  = seg->end;
 487         if (do_nonshared)
 488                 pr_info("DCSS %s of range %p to %p and type %s loaded as "
 489                         "exclusive-writable\n", name, (void*) seg->start_addr,
 490                         (void*) seg->end, segtype_string[seg->vm_segtype]);
 491         else {
 492                 pr_info("DCSS %s of range %p to %p and type %s loaded in "
 493                         "shared access mode\n", name, (void*) seg->start_addr,
 494                         (void*) seg->end, segtype_string[seg->vm_segtype]);
 495         }
 496         goto out;
 497  out_resource:
 498         release_resource(seg->res);
 499         kfree(seg->res);
 500  out_shared:
 501         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 502  out_free:
 503         kfree(seg);
 504  out:
 505         return rc;
 506 }
 507
 508 /*
 509  * this function loads a DCSS segment
 510  * name         : name of the DCSS
 511  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 512  *                1 indicates that the dcss should be exclusive for this linux image
 513  * addr         : will be filled with start address of the segment
 514  * end          : will be filled with end address of the segment
 515  * return values:
 516  * -ENOSYS  : we are not running on VM
 517  * -EIO     : could not perform query or load diagnose
 518  * -ENOENT  : no such segment
 519  * -EOPNOTSUPP: multi-part segment cannot be used with linux
 520  * -ENOSPC  : segment cannot be used (overlaps with storage)
 521  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 522  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 523  * -EPERM   : segment is currently loaded with incompatible permissions
 524  * -ENOMEM  : out of memory
 525  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 526  */
 527 int
 528 segment_load (char *name, int do_nonshared, unsigned long *addr,
 529                 unsigned long *end)
 530 {
 531         struct dcss_segment *seg;
 532         int rc;
 533
 534         if (!MACHINE_IS_VM)
 535                 return -ENOSYS;
 536
 537         mutex_lock(&dcss_lock);
 538         seg = segment_by_name (name);
 539         if (seg == NULL)
 540                 rc = __segment_load (name, do_nonshared, addr, end);
 541         else {
 542                 if (do_nonshared == seg->do_nonshared) {
 543                         atomic_inc(&seg->ref_count);
 544                         *addr = seg->start_addr;
 545                         *end  = seg->end;
 546                         rc    = seg->vm_segtype;
 547                 } else {
 548                         *addr = *end = 0;
 549                         rc    = -EPERM;
 550                 }
 551         }
 552         mutex_unlock(&dcss_lock);
 553         return rc;
 554 }
 555
 556 /*
 557  * this function modifies the shared state of a DCSS segment. note that
 558  * name         : name of the DCSS
 559  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 560  *                1 indicates that the dcss should be exclusive for this linux image
 561  * return values:
 562  * -EIO     : could not perform load diagnose (segment gone!)
 563  * -ENOENT  : no such segment (segment gone!)
 564  * -EAGAIN  : segment is in use by other exploiters, try later
 565  * -EINVAL  : no segment with the given name is currently loaded - name invalid
 566  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 567  * 0        : operation succeeded
 568  */
 569 int
 570 segment_modify_shared (char *name, int do_nonshared)
 571 {
 572         struct dcss_segment *seg;
 573         unsigned long start_addr, end_addr, dummy;
 574         int rc, diag_cc;
 575
 576         start_addr = end_addr = 0;
 577         mutex_lock(&dcss_lock);
 578         seg = segment_by_name (name);
 579         if (seg == NULL) {
 580                 rc = -EINVAL;
 581                 goto out_unlock;
 582         }
 583         if (do_nonshared == seg->do_nonshared) {
 584                 pr_info("DCSS %s is already in the requested access "
 585                         "mode\n", name);
 586                 rc = 0;
 587                 goto out_unlock;
 588         }
 589         if (atomic_read (&seg->ref_count) != 1) {
 590                 pr_warning("DCSS %s is in use and cannot be reloaded\n",
 591                            name);
 592                 rc = -EAGAIN;
 593                 goto out_unlock;
 594         }
 595         release_resource(seg->res);
 596         if (do_nonshared)
 597                 seg->res->flags &= ~IORESOURCE_READONLY;
 598         else
 599                 if (seg->vm_segtype == SEG_TYPE_SR ||
 600                     seg->vm_segtype == SEG_TYPE_ER)
 601                         seg->res->flags |= IORESOURCE_READONLY;
 602
 603         if (request_resource(&iomem_resource, seg->res)) {
 604                 pr_warning("DCSS %s overlaps with used memory resources "
 605                            "and cannot be reloaded\n", name);
 606                 rc = -EBUSY;
 607                 kfree(seg->res);
 608                 goto out_del_mem;
 609         }
 610
 611         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 612         if (do_nonshared)
 613                 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
 614                                 &start_addr, &end_addr);
 615         else
 616                 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
 617                                 &start_addr, &end_addr);
 618         if (diag_cc < 0) {
 619                 rc = diag_cc;
 620                 goto out_del_res;
 621         }
 622         if (diag_cc > 1) {
 623                 pr_warning("Reloading DCSS %s failed with rc=%ld\n", name,
 624                            end_addr);
 625                 rc = dcss_diag_translate_rc(end_addr);
 626                 goto out_del_res;
 627         }
 628         seg->start_addr = start_addr;
 629         seg->end = end_addr;
 630         seg->do_nonshared = do_nonshared;
 631         rc = 0;
 632         goto out_unlock;
 633  out_del_res:
 634         release_resource(seg->res);
 635         kfree(seg->res);
 636  out_del_mem:
 637         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 638         list_del(&seg->list);
 639         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 640         kfree(seg);
 641  out_unlock:
 642         mutex_unlock(&dcss_lock);
 643         return rc;
 644 }
 645
 646 /*
 647  * Decrease the use count of a DCSS segment and remove
 648  * it from the address space if nobody is using it
 649  * any longer.
 650  */
 651 void
 652 segment_unload(char *name)
 653 {
 654         unsigned long dummy;
 655         struct dcss_segment *seg;
 656
 657         if (!MACHINE_IS_VM)
 658                 return;
 659
 660         mutex_lock(&dcss_lock);
 661         seg = segment_by_name (name);
 662         if (seg == NULL) {
 663                 pr_err("Unloading unknown DCSS %s failed\n", name);
 664                 goto out_unlock;
 665         }
 666         if (atomic_dec_return(&seg->ref_count) != 0)
 667                 goto out_unlock;
 668         release_resource(seg->res);
 669         kfree(seg->res);
 670         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 671         list_del(&seg->list);
 672         dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
 673         kfree(seg);
 674 out_unlock:
 675         mutex_unlock(&dcss_lock);
 676 }
 677
 678 /*
 679  * save segment content permanently
 680  */
 681 void
 682 segment_save(char *name)
 683 {
 684         struct dcss_segment *seg;
 685         char cmd1[160];
 686         char cmd2[80];
 687         int i, response;
 688
 689         if (!MACHINE_IS_VM)
 690                 return;
 691
 692         mutex_lock(&dcss_lock);
 693         seg = segment_by_name (name);
 694
 695         if (seg == NULL) {
 696                 pr_err("Saving unknown DCSS %s failed\n", name);
 697                 goto out;
 698         }
 699
 700         sprintf(cmd1, "DEFSEG %s", name);
 701         for (i=0; i<seg->segcnt; i++) {
 702                 sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
 703                         seg->range[i].start >> PAGE_SHIFT,
 704                         seg->range[i].end >> PAGE_SHIFT,
 705                         segtype_string[seg->range[i].start & 0xff]);
 706         }
 707         sprintf(cmd2, "SAVESEG %s", name);
 708         response = 0;
 709         cpcmd(cmd1, NULL, 0, &response);
 710         if (response) {
 711                 pr_err("Saving a DCSS failed with DEFSEG response code "
 712                        "%i\n", response);
 713                 goto out;
 714         }
 715         cpcmd(cmd2, NULL, 0, &response);
 716         if (response) {
 717                 pr_err("Saving a DCSS failed with SAVESEG response code "
 718                        "%i\n", response);
 719                 goto out;
 720         }
 721 out:
 722         mutex_unlock(&dcss_lock);
 723 }
 724
 725 /*
 726  * print appropriate error message for segment_load()/segment_type()
 727  * return code
 728  */
 729 void segment_warning(int rc, char *seg_name)
 730 {
 731         switch (rc) {
 732         case -ENOENT:
 733                 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
 734                 break;
 735         case -ENOSYS:
 736                 pr_err("DCSS %s cannot be loaded or queried without "
 737                        "z/VM\n", seg_name);
 738                 break;
 739         case -EIO:
 740                 pr_err("Loading or querying DCSS %s resulted in a "
 741                        "hardware error\n", seg_name);
 742                 break;
 743         case -EOPNOTSUPP:
 744                 pr_err("DCSS %s has multiple page ranges and cannot be "
 745                        "loaded or queried\n", seg_name);
 746                 break;
 747         case -ENOSPC:
 748                 pr_err("DCSS %s overlaps with used storage and cannot "
 749                        "be loaded\n", seg_name);
 750                 break;
 751         case -EBUSY:
 752                 pr_err("%s needs used memory resources and cannot be "
 753                        "loaded or queried\n", seg_name);
 754                 break;
 755         case -EPERM:
 756                 pr_err("DCSS %s is already loaded in a different access "
 757                        "mode\n", seg_name);
 758                 break;
 759         case -ENOMEM:
 760                 pr_err("There is not enough memory to load or query "
 761                        "DCSS %s\n", seg_name);
 762                 break;
 763         case -ERANGE:
 764                 pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
 765                        "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
 766                 break;
 767         default:
 768                 break;
 769         }
 770 }
 771
 772 EXPORT_SYMBOL(segment_load);
 773 EXPORT_SYMBOL(segment_unload);
 774 EXPORT_SYMBOL(segment_save);
 775 EXPORT_SYMBOL(segment_type);
 776 EXPORT_SYMBOL(segment_modify_shared);
 777 EXPORT_SYMBOL(segment_warning);