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