arch/s390/mm/extmem.c

   1 /*
   2  * File...........: arch/s390/mm/extmem.c
   3  * Author(s)......: Carsten Otte <cotte@de.ibm.com>
   4  *                  Rob M van der Heij <rvdheij@nl.ibm.com>
   5  *                  Steven Shultz <shultzss@us.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * (C) IBM Corporation 2002-2004
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/string.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/list.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/bootmem.h>
  17 #include <asm/page.h>
  18 #include <asm/ebcdic.h>
  19 #include <asm/errno.h>
  20 #include <asm/extmem.h>
  21 #include <asm/cpcmd.h>
  22 #include <linux/ctype.h>
  23
  24 #define DCSS_DEBUG      /* Debug messages on/off */
  25
  26 #define DCSS_NAME "extmem"
  27 #ifdef DCSS_DEBUG
  28 #define PRINT_DEBUG(x...)       printk(KERN_DEBUG DCSS_NAME " debug:" x)
  29 #else
  30 #define PRINT_DEBUG(x...)   do {} while (0)
  31 #endif
  32 #define PRINT_INFO(x...)        printk(KERN_INFO DCSS_NAME " info:" x)
  33 #define PRINT_WARN(x...)        printk(KERN_WARNING DCSS_NAME " warning:" x)
  34 #define PRINT_ERR(x...)         printk(KERN_ERR DCSS_NAME " error:" x)
  35
  36
  37 #define DCSS_LOADSHR    0x00
  38 #define DCSS_LOADNSR    0x04
  39 #define DCSS_PURGESEG   0x08
  40 #define DCSS_FINDSEG    0x0c
  41 #define DCSS_LOADNOLY   0x10
  42 #define DCSS_SEGEXT     0x18
  43 #define DCSS_FINDSEGA   0x0c
  44
  45 struct qrange {
  46         unsigned int  start; // 3byte start address, 1 byte type
  47         unsigned int  end;   // 3byte end address, 1 byte reserved
  48 };
  49
  50 struct qout64 {
  51         int segstart;
  52         int segend;
  53         int segcnt;
  54         int segrcnt;
  55         struct qrange range[6];
  56 };
  57
  58 struct qin64 {
  59         char qopcode;
  60         char rsrv1[3];
  61         char qrcode;
  62         char rsrv2[3];
  63         char qname[8];
  64         unsigned int qoutptr;
  65         short int qoutlen;
  66 };
  67
  68 struct dcss_segment {
  69         struct list_head list;
  70         char dcss_name[8];
  71         unsigned long start_addr;
  72         unsigned long end;
  73         atomic_t ref_count;
  74         int do_nonshared;
  75         unsigned int vm_segtype;
  76         struct qrange range[6];
  77         int segcnt;
  78 };
  79
  80 static DEFINE_SPINLOCK(dcss_lock);
  81 static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
  82 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
  83                                         "EW/EN-MIXED" };
  84
  85 extern struct {
  86         unsigned long addr, size, type;
  87 } memory_chunk[MEMORY_CHUNKS];
  88
  89 /*
  90  * Create the 8 bytes, ebcdic VM segment name from
  91  * an ascii name.
  92  */
  93 static void inline
  94 dcss_mkname(char *name, char *dcss_name)
  95 {
  96         int i;
  97
  98         for (i = 0; i < 8; i++) {
  99                 if (name[i] == '\0')
 100                         break;
 101                 dcss_name[i] = toupper(name[i]);
 102         };
 103         for (; i < 8; i++)
 104                 dcss_name[i] = ' ';
 105         ASCEBC(dcss_name, 8);
 106 }
 107
 108
 109 /*
 110  * search all segments in dcss_list, and return the one
 111  * namend *name. If not found, return NULL.
 112  */
 113 static struct dcss_segment *
 114 segment_by_name (char *name)
 115 {
 116         char dcss_name[9];
 117         struct list_head *l;
 118         struct dcss_segment *tmp, *retval = NULL;
 119
 120         assert_spin_locked(&dcss_lock);
 121         dcss_mkname (name, dcss_name);
 122         list_for_each (l, &dcss_list) {
 123                 tmp = list_entry (l, struct dcss_segment, list);
 124                 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
 125                         retval = tmp;
 126                         break;
 127                 }
 128         }
 129         return retval;
 130 }
 131
 132
 133 /*
 134  * Perform a function on a dcss segment.
 135  */
 136 static inline int
 137 dcss_diag (__u8 func, void *parameter,
 138            unsigned long *ret1, unsigned long *ret2)
 139 {
 140         unsigned long rx, ry;
 141         int rc;
 142
 143         rx = (unsigned long) parameter;
 144         ry = (unsigned long) func;
 145         __asm__ __volatile__(
 146 #ifdef CONFIG_64BIT
 147                 "   sam31\n" // switch to 31 bit
 148                 "   diag    %0,%1,0x64\n"
 149                 "   sam64\n" // switch back to 64 bit
 150 #else
 151                 "   diag    %0,%1,0x64\n"
 152 #endif
 153                 "   ipm     %2\n"
 154                 "   srl     %2,28\n"
 155                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );
 156         *ret1 = rx;
 157         *ret2 = ry;
 158         return rc;
 159 }
 160
 161 static inline int
 162 dcss_diag_translate_rc (int vm_rc) {
 163         if (vm_rc == 44)
 164                 return -ENOENT;
 165         return -EIO;
 166 }
 167
 168
 169 /* do a diag to get info about a segment.
 170  * fills start_address, end and vm_segtype fields
 171  */
 172 static int
 173 query_segment_type (struct dcss_segment *seg)
 174 {
 175         struct qin64  *qin = kmalloc (sizeof(struct qin64), GFP_DMA);
 176         struct qout64 *qout = kmalloc (sizeof(struct qout64), GFP_DMA);
 177
 178         int diag_cc, rc, i;
 179         unsigned long dummy, vmrc;
 180
 181         if ((qin == NULL) || (qout == NULL)) {
 182                 rc = -ENOMEM;
 183                 goto out_free;
 184         }
 185
 186         /* initialize diag input parameters */
 187         qin->qopcode = DCSS_FINDSEGA;
 188         qin->qoutptr = (unsigned long) qout;
 189         qin->qoutlen = sizeof(struct qout64);
 190         memcpy (qin->qname, seg->dcss_name, 8);
 191
 192         diag_cc = dcss_diag (DCSS_SEGEXT, qin, &dummy, &vmrc);
 193
 194         if (diag_cc > 1) {
 195                 PRINT_WARN ("segment_type: diag returned error %ld\n", vmrc);
 196                 rc = dcss_diag_translate_rc (vmrc);
 197                 goto out_free;
 198         }
 199
 200         if (qout->segcnt > 6) {
 201                 rc = -ENOTSUPP;
 202                 goto out_free;
 203         }
 204
 205         if (qout->segcnt == 1) {
 206                 seg->vm_segtype = qout->range[0].start & 0xff;
 207         } else {
 208                 /* multi-part segment. only one type supported here:
 209                     - all parts are contiguous
 210                     - all parts are either EW or EN type
 211                     - maximum 6 parts allowed */
 212                 unsigned long start = qout->segstart >> PAGE_SHIFT;
 213                 for (i=0; i<qout->segcnt; i++) {
 214                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
 215                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
 216                                 rc = -ENOTSUPP;
 217                                 goto out_free;
 218                         }
 219                         if (start != qout->range[i].start >> PAGE_SHIFT) {
 220                                 rc = -ENOTSUPP;
 221                                 goto out_free;
 222                         }
 223                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
 224                 }
 225                 seg->vm_segtype = SEG_TYPE_EWEN;
 226         }
 227
 228         /* analyze diag output and update seg */
 229         seg->start_addr = qout->segstart;
 230         seg->end = qout->segend;
 231
 232         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
 233         seg->segcnt = qout->segcnt;
 234
 235         rc = 0;
 236
 237  out_free:
 238         kfree(qin);
 239         kfree(qout);
 240         return rc;
 241 }
 242
 243 /*
 244  * check if the given segment collides with guest storage.
 245  * returns 1 if this is the case, 0 if no collision was found
 246  */
 247 static int
 248 segment_overlaps_storage(struct dcss_segment *seg)
 249 {
 250         int i;
 251
 252         for (i=0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
 253                 if (memory_chunk[i].type != 0)
 254                         continue;
 255                 if ((memory_chunk[i].addr >> 20) > (seg->end >> 20))
 256                         continue;
 257                 if (((memory_chunk[i].addr + memory_chunk[i].size - 1) >> 20)
 258                                 < (seg->start_addr >> 20))
 259                         continue;
 260                 return 1;
 261         }
 262         return 0;
 263 }
 264
 265 /*
 266  * check if segment collides with other segments that are currently loaded
 267  * returns 1 if this is the case, 0 if no collision was found
 268  */
 269 static int
 270 segment_overlaps_others (struct dcss_segment *seg)
 271 {
 272         struct list_head *l;
 273         struct dcss_segment *tmp;
 274
 275         assert_spin_locked(&dcss_lock);
 276         list_for_each(l, &dcss_list) {
 277                 tmp = list_entry(l, struct dcss_segment, list);
 278                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
 279                         continue;
 280                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
 281                         continue;
 282                 if (seg == tmp)
 283                         continue;
 284                 return 1;
 285         }
 286         return 0;
 287 }
 288
 289 /*
 290  * check if segment exceeds the kernel mapping range (detected or set via mem=)
 291  * returns 1 if this is the case, 0 if segment fits into the range
 292  */
 293 static inline int
 294 segment_exceeds_range (struct dcss_segment *seg)
 295 {
 296         int seg_last_pfn = (seg->end) >> PAGE_SHIFT;
 297         if (seg_last_pfn > max_pfn)
 298                 return 1;
 299         return 0;
 300 }
 301
 302 /*
 303  * get info about a segment
 304  * possible return values:
 305  * -ENOSYS  : we are not running on VM
 306  * -EIO     : could not perform query diagnose
 307  * -ENOENT  : no such segment
 308  * -ENOTSUPP: multi-part segment cannot be used with linux
 309  * -ENOSPC  : segment cannot be used (overlaps with storage)
 310  * -ENOMEM  : out of memory
 311  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 312  */
 313 int
 314 segment_type (char* name)
 315 {
 316         int rc;
 317         struct dcss_segment seg;
 318
 319         if (!MACHINE_IS_VM)
 320                 return -ENOSYS;
 321
 322         dcss_mkname(name, seg.dcss_name);
 323         rc = query_segment_type (&seg);
 324         if (rc < 0)
 325                 return rc;
 326         return seg.vm_segtype;
 327 }
 328
 329 /*
 330  * real segment loading function, called from segment_load
 331  */
 332 static int
 333 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
 334 {
 335         struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
 336                         GFP_DMA);
 337         int dcss_command, rc, diag_cc;
 338
 339         if (seg == NULL) {
 340                 rc = -ENOMEM;
 341                 goto out;
 342         }
 343         dcss_mkname (name, seg->dcss_name);
 344         rc = query_segment_type (seg);
 345         if (rc < 0)
 346                 goto out_free;
 347         if (segment_exceeds_range(seg)) {
 348                 PRINT_WARN ("segment_load: not loading segment %s - exceeds"
 349                                 " kernel mapping range\n",name);
 350                 rc = -ERANGE;
 351                 goto out_free;
 352         }
 353         if (segment_overlaps_storage(seg)) {
 354                 PRINT_WARN ("segment_load: not loading segment %s - overlaps"
 355                                 " storage\n",name);
 356                 rc = -ENOSPC;
 357                 goto out_free;
 358         }
 359         if (segment_overlaps_others(seg)) {
 360                 PRINT_WARN ("segment_load: not loading segment %s - overlaps"
 361                                 " other segments\n",name);
 362                 rc = -EBUSY;
 363                 goto out_free;
 364         }
 365         if (do_nonshared)
 366                 dcss_command = DCSS_LOADNSR;
 367         else
 368                 dcss_command = DCSS_LOADNOLY;
 369
 370         diag_cc = dcss_diag(dcss_command, seg->dcss_name,
 371                         &seg->start_addr, &seg->end);
 372         if (diag_cc > 1) {
 373                 PRINT_WARN ("segment_load: could not load segment %s - "
 374                                 "diag returned error (%ld)\n",name,seg->end);
 375                 rc = dcss_diag_translate_rc (seg->end);
 376                 dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 377                                 &seg->start_addr, &seg->end);
 378                 goto out_free;
 379         }
 380         seg->do_nonshared = do_nonshared;
 381         atomic_set(&seg->ref_count, 1);
 382         list_add(&seg->list, &dcss_list);
 383         rc = seg->vm_segtype;
 384         *addr = seg->start_addr;
 385         *end  = seg->end;
 386         if (do_nonshared)
 387                 PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
 388                                 "type %s in non-shared mode\n", name,
 389                                 (void*)seg->start_addr, (void*)seg->end,
 390                                 segtype_string[seg->vm_segtype]);
 391         else
 392                 PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
 393                                 "type %s in shared mode\n", name,
 394                                 (void*)seg->start_addr, (void*)seg->end,
 395                                 segtype_string[seg->vm_segtype]);
 396         goto out;
 397  out_free:
 398         kfree(seg);
 399  out:
 400         return rc;
 401 }
 402
 403 /*
 404  * this function loads a DCSS segment
 405  * name         : name of the DCSS
 406  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 407  *                1 indicates that the dcss should be exclusive for this linux image
 408  * addr         : will be filled with start address of the segment
 409  * end          : will be filled with end address of the segment
 410  * return values:
 411  * -ENOSYS  : we are not running on VM
 412  * -EIO     : could not perform query or load diagnose
 413  * -ENOENT  : no such segment
 414  * -ENOTSUPP: multi-part segment cannot be used with linux
 415  * -ENOSPC  : segment cannot be used (overlaps with storage)
 416  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 417  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 418  * -EPERM   : segment is currently loaded with incompatible permissions
 419  * -ENOMEM  : out of memory
 420  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 421  */
 422 int
 423 segment_load (char *name, int do_nonshared, unsigned long *addr,
 424                 unsigned long *end)
 425 {
 426         struct dcss_segment *seg;
 427         int rc;
 428
 429         if (!MACHINE_IS_VM)
 430                 return -ENOSYS;
 431
 432         spin_lock (&dcss_lock);
 433         seg = segment_by_name (name);
 434         if (seg == NULL)
 435                 rc = __segment_load (name, do_nonshared, addr, end);
 436         else {
 437                 if (do_nonshared == seg->do_nonshared) {
 438                         atomic_inc(&seg->ref_count);
 439                         *addr = seg->start_addr;
 440                         *end  = seg->end;
 441                         rc    = seg->vm_segtype;
 442                 } else {
 443                         *addr = *end = 0;
 444                         rc    = -EPERM;
 445                 }
 446         }
 447         spin_unlock (&dcss_lock);
 448         return rc;
 449 }
 450
 451 /*
 452  * this function modifies the shared state of a DCSS segment. note that
 453  * name         : name of the DCSS
 454  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 455  *                1 indicates that the dcss should be exclusive for this linux image
 456  * return values:
 457  * -EIO     : could not perform load diagnose (segment gone!)
 458  * -ENOENT  : no such segment (segment gone!)
 459  * -EAGAIN  : segment is in use by other exploiters, try later
 460  * -EINVAL  : no segment with the given name is currently loaded - name invalid
 461  * 0        : operation succeeded
 462  */
 463 int
 464 segment_modify_shared (char *name, int do_nonshared)
 465 {
 466         struct dcss_segment *seg;
 467         unsigned long dummy;
 468         int dcss_command, rc, diag_cc;
 469
 470         spin_lock (&dcss_lock);
 471         seg = segment_by_name (name);
 472         if (seg == NULL) {
 473                 rc = -EINVAL;
 474                 goto out_unlock;
 475         }
 476         if (do_nonshared == seg->do_nonshared) {
 477                 PRINT_INFO ("segment_modify_shared: not reloading segment %s"
 478                                 " - already in requested mode\n",name);
 479                 rc = 0;
 480                 goto out_unlock;
 481         }
 482         if (atomic_read (&seg->ref_count) != 1) {
 483                 PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
 484                                 "segment is in use by other driver(s)\n",name);
 485                 rc = -EAGAIN;
 486                 goto out_unlock;
 487         }
 488         dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 489                   &dummy, &dummy);
 490         if (do_nonshared)
 491                 dcss_command = DCSS_LOADNSR;
 492         else
 493         dcss_command = DCSS_LOADNOLY;
 494         diag_cc = dcss_diag(dcss_command, seg->dcss_name,
 495                         &seg->start_addr, &seg->end);
 496         if (diag_cc > 1) {
 497                 PRINT_WARN ("segment_modify_shared: could not reload segment %s"
 498                                 " - diag returned error (%ld)\n",name,seg->end);
 499                 rc = dcss_diag_translate_rc (seg->end);
 500                 goto out_del;
 501         }
 502         seg->do_nonshared = do_nonshared;
 503         rc = 0;
 504         goto out_unlock;
 505  out_del:
 506         list_del(&seg->list);
 507         dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 508                   &dummy, &dummy);
 509         kfree(seg);
 510  out_unlock:
 511         spin_unlock(&dcss_lock);
 512         return rc;
 513 }
 514
 515 /*
 516  * Decrease the use count of a DCSS segment and remove
 517  * it from the address space if nobody is using it
 518  * any longer.
 519  */
 520 void
 521 segment_unload(char *name)
 522 {
 523         unsigned long dummy;
 524         struct dcss_segment *seg;
 525
 526         if (!MACHINE_IS_VM)
 527                 return;
 528
 529         spin_lock(&dcss_lock);
 530         seg = segment_by_name (name);
 531         if (seg == NULL) {
 532                 PRINT_ERR ("could not find segment %s in segment_unload, "
 533                                 "please report to linux390@de.ibm.com\n",name);
 534                 goto out_unlock;
 535         }
 536         if (atomic_dec_return(&seg->ref_count) == 0) {
 537                 list_del(&seg->list);
 538                 dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 539                           &dummy, &dummy);
 540                 kfree(seg);
 541         }
 542 out_unlock:
 543         spin_unlock(&dcss_lock);
 544 }
 545
 546 /*
 547  * save segment content permanently
 548  */
 549 void
 550 segment_save(char *name)
 551 {
 552         struct dcss_segment *seg;
 553         int startpfn = 0;
 554         int endpfn = 0;
 555         char cmd1[160];
 556         char cmd2[80];
 557         int i, response;
 558
 559         if (!MACHINE_IS_VM)
 560                 return;
 561
 562         spin_lock(&dcss_lock);
 563         seg = segment_by_name (name);
 564
 565         if (seg == NULL) {
 566                 PRINT_ERR ("could not find segment %s in segment_save, please report to linux390@de.ibm.com\n",name);
 567                 return;
 568         }
 569
 570         startpfn = seg->start_addr >> PAGE_SHIFT;
 571         endpfn = (seg->end) >> PAGE_SHIFT;
 572         sprintf(cmd1, "DEFSEG %s", name);
 573         for (i=0; i<seg->segcnt; i++) {
 574                 sprintf(cmd1+strlen(cmd1), " %X-%X %s",
 575                         seg->range[i].start >> PAGE_SHIFT,
 576                         seg->range[i].end >> PAGE_SHIFT,
 577                         segtype_string[seg->range[i].start & 0xff]);
 578         }
 579         sprintf(cmd2, "SAVESEG %s", name);
 580         response = 0;
 581         cpcmd(cmd1, NULL, 0, &response);
 582         if (response) {
 583                 PRINT_ERR("segment_save: DEFSEG failed with response code %i\n",
 584                           response);
 585                 goto out;
 586         }
 587         cpcmd(cmd2, NULL, 0, &response);
 588         if (response) {
 589                 PRINT_ERR("segment_save: SAVESEG failed with response code %i\n",
 590                           response);
 591                 goto out;
 592         }
 593 out:
 594         spin_unlock(&dcss_lock);
 595 }
 596
 597 EXPORT_SYMBOL(segment_load);
 598 EXPORT_SYMBOL(segment_unload);
 599 EXPORT_SYMBOL(segment_save);
 600 EXPORT_SYMBOL(segment_type);
 601 EXPORT_SYMBOL(segment_modify_shared);