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_ARCH_S390X
 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                 rc = dcss_diag_translate_rc (vmrc);
 196                 goto out_free;
 197         }
 198
 199         if (qout->segcnt > 6) {
 200                 rc = -ENOTSUPP;
 201                 goto out_free;
 202         }
 203
 204         if (qout->segcnt == 1) {
 205                 seg->vm_segtype = qout->range[0].start & 0xff;
 206         } else {
 207                 /* multi-part segment. only one type supported here:
 208                     - all parts are contiguous
 209                     - all parts are either EW or EN type
 210                     - maximum 6 parts allowed */
 211                 unsigned long start = qout->segstart >> PAGE_SHIFT;
 212                 for (i=0; i<qout->segcnt; i++) {
 213                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
 214                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
 215                                 rc = -ENOTSUPP;
 216                                 goto out_free;
 217                         }
 218                         if (start != qout->range[i].start >> PAGE_SHIFT) {
 219                                 rc = -ENOTSUPP;
 220                                 goto out_free;
 221                         }
 222                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
 223                 }
 224                 seg->vm_segtype = SEG_TYPE_EWEN;
 225         }
 226
 227         /* analyze diag output and update seg */
 228         seg->start_addr = qout->segstart;
 229         seg->end = qout->segend;
 230
 231         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
 232         seg->segcnt = qout->segcnt;
 233
 234         rc = 0;
 235
 236  out_free:
 237         if (qin) kfree(qin);
 238         if (qout) kfree(qout);
 239         return rc;
 240 }
 241
 242 /*
 243  * check if the given segment collides with guest storage.
 244  * returns 1 if this is the case, 0 if no collision was found
 245  */
 246 static int
 247 segment_overlaps_storage(struct dcss_segment *seg)
 248 {
 249         int i;
 250
 251         for (i=0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
 252                 if (memory_chunk[i].type != 0)
 253                         continue;
 254                 if ((memory_chunk[i].addr >> 20) > (seg->end >> 20))
 255                         continue;
 256                 if (((memory_chunk[i].addr + memory_chunk[i].size - 1) >> 20)
 257                                 < (seg->start_addr >> 20))
 258                         continue;
 259                 return 1;
 260         }
 261         return 0;
 262 }
 263
 264 /*
 265  * check if segment collides with other segments that are currently loaded
 266  * returns 1 if this is the case, 0 if no collision was found
 267  */
 268 static int
 269 segment_overlaps_others (struct dcss_segment *seg)
 270 {
 271         struct list_head *l;
 272         struct dcss_segment *tmp;
 273
 274         assert_spin_locked(&dcss_lock);
 275         list_for_each(l, &dcss_list) {
 276                 tmp = list_entry(l, struct dcss_segment, list);
 277                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
 278                         continue;
 279                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
 280                         continue;
 281                 if (seg == tmp)
 282                         continue;
 283                 return 1;
 284         }
 285         return 0;
 286 }
 287
 288 /*
 289  * check if segment exceeds the kernel mapping range (detected or set via mem=)
 290  * returns 1 if this is the case, 0 if segment fits into the range
 291  */
 292 static inline int
 293 segment_exceeds_range (struct dcss_segment *seg)
 294 {
 295         int seg_last_pfn = (seg->end) >> PAGE_SHIFT;
 296         if (seg_last_pfn > max_pfn)
 297                 return 1;
 298         return 0;
 299 }
 300
 301 /*
 302  * get info about a segment
 303  * possible return values:
 304  * -ENOSYS  : we are not running on VM
 305  * -EIO     : could not perform query diagnose
 306  * -ENOENT  : no such segment
 307  * -ENOTSUPP: multi-part segment cannot be used with linux
 308  * -ENOSPC  : segment cannot be used (overlaps with storage)
 309  * -ENOMEM  : out of memory
 310  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 311  */
 312 int
 313 segment_type (char* name)
 314 {
 315         int rc;
 316         struct dcss_segment seg;
 317
 318         if (!MACHINE_IS_VM)
 319                 return -ENOSYS;
 320
 321         dcss_mkname(name, seg.dcss_name);
 322         rc = query_segment_type (&seg);
 323         if (rc < 0)
 324                 return rc;
 325         return seg.vm_segtype;
 326 }
 327
 328 /*
 329  * real segment loading function, called from segment_load
 330  */
 331 static int
 332 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
 333 {
 334         struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
 335                         GFP_DMA);
 336         int dcss_command, rc, diag_cc;
 337
 338         if (seg == NULL) {
 339                 rc = -ENOMEM;
 340                 goto out;
 341         }
 342         dcss_mkname (name, seg->dcss_name);
 343         rc = query_segment_type (seg);
 344         if (rc < 0)
 345                 goto out_free;
 346         if (segment_exceeds_range(seg)) {
 347                 PRINT_WARN ("segment_load: not loading segment %s - exceeds"
 348                                 " kernel mapping range\n",name);
 349                 rc = -ERANGE;
 350                 goto out_free;
 351         }
 352         if (segment_overlaps_storage(seg)) {
 353                 PRINT_WARN ("segment_load: not loading segment %s - overlaps"
 354                                 " storage\n",name);
 355                 rc = -ENOSPC;
 356                 goto out_free;
 357         }
 358         if (segment_overlaps_others(seg)) {
 359                 PRINT_WARN ("segment_load: not loading segment %s - overlaps"
 360                                 " other segments\n",name);
 361                 rc = -EBUSY;
 362                 goto out_free;
 363         }
 364         if (do_nonshared)
 365                 dcss_command = DCSS_LOADNSR;
 366         else
 367                 dcss_command = DCSS_LOADNOLY;
 368
 369         diag_cc = dcss_diag(dcss_command, seg->dcss_name,
 370                         &seg->start_addr, &seg->end);
 371         if (diag_cc > 1) {
 372                 PRINT_WARN ("segment_load: could not load segment %s - "
 373                                 "diag returned error (%ld)\n",name,seg->end);
 374                 rc = dcss_diag_translate_rc (seg->end);
 375                 dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 376                                 &seg->start_addr, &seg->end);
 377                 goto out_free;
 378         }
 379         seg->do_nonshared = do_nonshared;
 380         atomic_set(&seg->ref_count, 1);
 381         list_add(&seg->list, &dcss_list);
 382         rc = seg->vm_segtype;
 383         *addr = seg->start_addr;
 384         *end  = seg->end;
 385         if (do_nonshared)
 386                 PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
 387                                 "type %s in non-shared mode\n", name,
 388                                 (void*)seg->start_addr, (void*)seg->end,
 389                                 segtype_string[seg->vm_segtype]);
 390         else
 391                 PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
 392                                 "type %s in shared mode\n", name,
 393                                 (void*)seg->start_addr, (void*)seg->end,
 394                                 segtype_string[seg->vm_segtype]);
 395         goto out;
 396  out_free:
 397         kfree (seg);
 398  out:
 399         return rc;
 400 }
 401
 402 /*
 403  * this function loads a DCSS segment
 404  * name         : name of the DCSS
 405  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 406  *                1 indicates that the dcss should be exclusive for this linux image
 407  * addr         : will be filled with start address of the segment
 408  * end          : will be filled with end address of the segment
 409  * return values:
 410  * -ENOSYS  : we are not running on VM
 411  * -EIO     : could not perform query or load diagnose
 412  * -ENOENT  : no such segment
 413  * -ENOTSUPP: multi-part segment cannot be used with linux
 414  * -ENOSPC  : segment cannot be used (overlaps with storage)
 415  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 416  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 417  * -EPERM   : segment is currently loaded with incompatible permissions
 418  * -ENOMEM  : out of memory
 419  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 420  */
 421 int
 422 segment_load (char *name, int do_nonshared, unsigned long *addr,
 423                 unsigned long *end)
 424 {
 425         struct dcss_segment *seg;
 426         int rc;
 427
 428         if (!MACHINE_IS_VM)
 429                 return -ENOSYS;
 430
 431         spin_lock (&dcss_lock);
 432         seg = segment_by_name (name);
 433         if (seg == NULL)
 434                 rc = __segment_load (name, do_nonshared, addr, end);
 435         else {
 436                 if (do_nonshared == seg->do_nonshared) {
 437                         atomic_inc(&seg->ref_count);
 438                         *addr = seg->start_addr;
 439                         *end  = seg->end;
 440                         rc    = seg->vm_segtype;
 441                 } else {
 442                         *addr = *end = 0;
 443                         rc    = -EPERM;
 444                 }
 445         }
 446         spin_unlock (&dcss_lock);
 447         return rc;
 448 }
 449
 450 /*
 451  * this function modifies the shared state of a DCSS segment. note that
 452  * name         : name of the DCSS
 453  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 454  *                1 indicates that the dcss should be exclusive for this linux image
 455  * return values:
 456  * -EIO     : could not perform load diagnose (segment gone!)
 457  * -ENOENT  : no such segment (segment gone!)
 458  * -EAGAIN  : segment is in use by other exploiters, try later
 459  * -EINVAL  : no segment with the given name is currently loaded - name invalid
 460  * 0        : operation succeeded
 461  */
 462 int
 463 segment_modify_shared (char *name, int do_nonshared)
 464 {
 465         struct dcss_segment *seg;
 466         unsigned long dummy;
 467         int dcss_command, rc, diag_cc;
 468
 469         spin_lock (&dcss_lock);
 470         seg = segment_by_name (name);
 471         if (seg == NULL) {
 472                 rc = -EINVAL;
 473                 goto out_unlock;
 474         }
 475         if (do_nonshared == seg->do_nonshared) {
 476                 PRINT_INFO ("segment_modify_shared: not reloading segment %s"
 477                                 " - already in requested mode\n",name);
 478                 rc = 0;
 479                 goto out_unlock;
 480         }
 481         if (atomic_read (&seg->ref_count) != 1) {
 482                 PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
 483                                 "segment is in use by other driver(s)\n",name);
 484                 rc = -EAGAIN;
 485                 goto out_unlock;
 486         }
 487         dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 488                   &dummy, &dummy);
 489         if (do_nonshared)
 490                 dcss_command = DCSS_LOADNSR;
 491         else
 492         dcss_command = DCSS_LOADNOLY;
 493         diag_cc = dcss_diag(dcss_command, seg->dcss_name,
 494                         &seg->start_addr, &seg->end);
 495         if (diag_cc > 1) {
 496                 PRINT_WARN ("segment_modify_shared: could not reload segment %s"
 497                                 " - diag returned error (%ld)\n",name,seg->end);
 498                 rc = dcss_diag_translate_rc (seg->end);
 499                 goto out_del;
 500         }
 501         seg->do_nonshared = do_nonshared;
 502         rc = 0;
 503         goto out_unlock;
 504  out_del:
 505         list_del(&seg->list);
 506         dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 507                   &dummy, &dummy);
 508         kfree (seg);
 509  out_unlock:
 510         spin_unlock(&dcss_lock);
 511         return rc;
 512 }
 513
 514 /*
 515  * Decrease the use count of a DCSS segment and remove
 516  * it from the address space if nobody is using it
 517  * any longer.
 518  */
 519 void
 520 segment_unload(char *name)
 521 {
 522         unsigned long dummy;
 523         struct dcss_segment *seg;
 524
 525         if (!MACHINE_IS_VM)
 526                 return;
 527
 528         spin_lock(&dcss_lock);
 529         seg = segment_by_name (name);
 530         if (seg == NULL) {
 531                 PRINT_ERR ("could not find segment %s in segment_unload, "
 532                                 "please report to linux390@de.ibm.com\n",name);
 533                 goto out_unlock;
 534         }
 535         if (atomic_dec_return(&seg->ref_count) == 0) {
 536                 list_del(&seg->list);
 537                 dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 538                           &dummy, &dummy);
 539                 kfree(seg);
 540         }
 541 out_unlock:
 542         spin_unlock(&dcss_lock);
 543 }
 544
 545 /*
 546  * save segment content permanently
 547  */
 548 void
 549 segment_save(char *name)
 550 {
 551         struct dcss_segment *seg;
 552         int startpfn = 0;
 553         int endpfn = 0;
 554         char cmd1[160];
 555         char cmd2[80];
 556         int i;
 557
 558         if (!MACHINE_IS_VM)
 559                 return;
 560
 561         spin_lock(&dcss_lock);
 562         seg = segment_by_name (name);
 563
 564         if (seg == NULL) {
 565                 PRINT_ERR ("could not find segment %s in segment_save, please report to linux390@de.ibm.com\n",name);
 566                 return;
 567         }
 568
 569         startpfn = seg->start_addr >> PAGE_SHIFT;
 570         endpfn = (seg->end) >> PAGE_SHIFT;
 571         sprintf(cmd1, "DEFSEG %s", name);
 572         for (i=0; i<seg->segcnt; i++) {
 573                 sprintf(cmd1+strlen(cmd1), " %X-%X %s",
 574                         seg->range[i].start >> PAGE_SHIFT,
 575                         seg->range[i].end >> PAGE_SHIFT,
 576                         segtype_string[seg->range[i].start & 0xff]);
 577         }
 578         sprintf(cmd2, "SAVESEG %s", name);
 579         cpcmd(cmd1, NULL, 0);
 580         cpcmd(cmd2, NULL, 0);
 581         spin_unlock(&dcss_lock);
 582 }
 583
 584 EXPORT_SYMBOL(segment_load);
 585 EXPORT_SYMBOL(segment_unload);
 586 EXPORT_SYMBOL(segment_save);
 587 EXPORT_SYMBOL(segment_type);
 588 EXPORT_SYMBOL(segment_modify_shared);