linux/arch/s390/mm/extmem.c
<<
>>
Prefs
   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
  48struct qrange {
  49        unsigned int  start; // 3byte start address, 1 byte type
  50        unsigned int  end;   // 3byte end address, 1 byte reserved
  51};
  52
  53struct qout64 {
  54        int segstart;
  55        int segend;
  56        int segcnt;
  57        int segrcnt;
  58        struct qrange range[6];
  59};
  60
  61struct 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
  71struct 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
  85static DEFINE_MUTEX(dcss_lock);
  86static LIST_HEAD(dcss_list);
  87static 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 */
  94static void
  95dcss_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 */
 114static struct dcss_segment *
 115segment_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 */
 137static inline int
 138dcss_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
 162static inline int
 163dcss_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 */
 173static int
 174query_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 */
 255int
 256segment_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 */
 274static 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 = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 291
 292        if (rc)
 293                goto out_free;
 294
 295        seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 296        if (seg->res == NULL) {
 297                rc = -ENOMEM;
 298                goto out_shared;
 299        }
 300        seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 301        seg->res->start = seg->start_addr;
 302        seg->res->end = seg->end;
 303        memcpy(&seg->res_name, seg->dcss_name, 8);
 304        EBCASC(seg->res_name, 8);
 305        seg->res_name[8] = '\0';
 306        strncat(seg->res_name, " (DCSS)", 7);
 307        seg->res->name = seg->res_name;
 308        rc = seg->vm_segtype;
 309        if (rc == SEG_TYPE_SC ||
 310            ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
 311                seg->res->flags |= IORESOURCE_READONLY;
 312        if (request_resource(&iomem_resource, seg->res)) {
 313                rc = -EBUSY;
 314                kfree(seg->res);
 315                goto out_shared;
 316        }
 317
 318        if (do_nonshared)
 319                dcss_command = DCSS_LOADNSR;
 320        else
 321                dcss_command = DCSS_LOADNOLY;
 322
 323        diag_cc = dcss_diag(dcss_command, seg->dcss_name,
 324                        &seg->start_addr, &seg->end);
 325        if (diag_cc > 1) {
 326                PRINT_WARN ("segment_load: could not load segment %s - "
 327                                "diag returned error (%ld)\n",name,seg->end);
 328                rc = dcss_diag_translate_rc (seg->end);
 329                dcss_diag(DCSS_PURGESEG, seg->dcss_name,
 330                                &seg->start_addr, &seg->end);
 331                goto out_resource;
 332        }
 333        seg->do_nonshared = do_nonshared;
 334        atomic_set(&seg->ref_count, 1);
 335        list_add(&seg->list, &dcss_list);
 336        *addr = seg->start_addr;
 337        *end  = seg->end;
 338        if (do_nonshared)
 339                PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
 340                                "type %s in non-shared mode\n", name,
 341                                (void*)seg->start_addr, (void*)seg->end,
 342                                segtype_string[seg->vm_segtype]);
 343        else {
 344                PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
 345                                "type %s in shared mode\n", name,
 346                                (void*)seg->start_addr, (void*)seg->end,
 347                                segtype_string[seg->vm_segtype]);
 348        }
 349        goto out;
 350 out_resource:
 351        release_resource(seg->res);
 352        kfree(seg->res);
 353 out_shared:
 354        vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 355 out_free:
 356        kfree(seg);
 357 out:
 358        return rc;
 359}
 360
 361/*
 362 * this function loads a DCSS segment
 363 * name         : name of the DCSS
 364 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 365 *                1 indicates that the dcss should be exclusive for this linux image
 366 * addr         : will be filled with start address of the segment
 367 * end          : will be filled with end address of the segment
 368 * return values:
 369 * -ENOSYS  : we are not running on VM
 370 * -EIO     : could not perform query or load diagnose
 371 * -ENOENT  : no such segment
 372 * -ENOTSUPP: multi-part segment cannot be used with linux
 373 * -ENOSPC  : segment cannot be used (overlaps with storage)
 374 * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 375 * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 376 * -EPERM   : segment is currently loaded with incompatible permissions
 377 * -ENOMEM  : out of memory
 378 * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 379 */
 380int
 381segment_load (char *name, int do_nonshared, unsigned long *addr,
 382                unsigned long *end)
 383{
 384        struct dcss_segment *seg;
 385        int rc;
 386
 387        if (!MACHINE_IS_VM)
 388                return -ENOSYS;
 389
 390        mutex_lock(&dcss_lock);
 391        seg = segment_by_name (name);
 392        if (seg == NULL)
 393                rc = __segment_load (name, do_nonshared, addr, end);
 394        else {
 395                if (do_nonshared == seg->do_nonshared) {
 396                        atomic_inc(&seg->ref_count);
 397                        *addr = seg->start_addr;
 398                        *end  = seg->end;
 399                        rc    = seg->vm_segtype;
 400                } else {
 401                        *addr = *end = 0;
 402                        rc    = -EPERM;
 403                }
 404        }
 405        mutex_unlock(&dcss_lock);
 406        return rc;
 407}
 408
 409/*
 410 * this function modifies the shared state of a DCSS segment. note that
 411 * name         : name of the DCSS
 412 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 413 *                1 indicates that the dcss should be exclusive for this linux image
 414 * return values:
 415 * -EIO     : could not perform load diagnose (segment gone!)
 416 * -ENOENT  : no such segment (segment gone!)
 417 * -EAGAIN  : segment is in use by other exploiters, try later
 418 * -EINVAL  : no segment with the given name is currently loaded - name invalid
 419 * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 420 * 0        : operation succeeded
 421 */
 422int
 423segment_modify_shared (char *name, int do_nonshared)
 424{
 425        struct dcss_segment *seg;
 426        unsigned long dummy;
 427        int dcss_command, rc, diag_cc;
 428
 429        mutex_lock(&dcss_lock);
 430        seg = segment_by_name (name);
 431        if (seg == NULL) {
 432                rc = -EINVAL;
 433                goto out_unlock;
 434        }
 435        if (do_nonshared == seg->do_nonshared) {
 436                PRINT_INFO ("segment_modify_shared: not reloading segment %s"
 437                                " - already in requested mode\n",name);
 438                rc = 0;
 439                goto out_unlock;
 440        }
 441        if (atomic_read (&seg->ref_count) != 1) {
 442                PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
 443                                "segment is in use by other driver(s)\n",name);
 444                rc = -EAGAIN;
 445                goto out_unlock;
 446        }
 447        release_resource(seg->res);
 448        if (do_nonshared) {
 449                dcss_command = DCSS_LOADNSR;
 450                seg->res->flags &= ~IORESOURCE_READONLY;
 451        } else {
 452                dcss_command = DCSS_LOADNOLY;
 453                if (seg->vm_segtype == SEG_TYPE_SR ||
 454                    seg->vm_segtype == SEG_TYPE_ER)
 455                        seg->res->flags |= IORESOURCE_READONLY;
 456        }
 457        if (request_resource(&iomem_resource, seg->res)) {
 458                PRINT_WARN("segment_modify_shared: could not reload segment %s"
 459                           " - overlapping resources\n", name);
 460                rc = -EBUSY;
 461                kfree(seg->res);
 462                goto out_del;
 463        }
 464        dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
 465        diag_cc = dcss_diag(dcss_command, seg->dcss_name,
 466                        &seg->start_addr, &seg->end);
 467        if (diag_cc > 1) {
 468                PRINT_WARN ("segment_modify_shared: could not reload segment %s"
 469                                " - diag returned error (%ld)\n",name,seg->end);
 470                rc = dcss_diag_translate_rc (seg->end);
 471                goto out_del;
 472        }
 473        seg->do_nonshared = do_nonshared;
 474        rc = 0;
 475        goto out_unlock;
 476 out_del:
 477        vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 478        list_del(&seg->list);
 479        dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
 480        kfree(seg);
 481 out_unlock:
 482        mutex_unlock(&dcss_lock);
 483        return rc;
 484}
 485
 486/*
 487 * Decrease the use count of a DCSS segment and remove
 488 * it from the address space if nobody is using it
 489 * any longer.
 490 */
 491void
 492segment_unload(char *name)
 493{
 494        unsigned long dummy;
 495        struct dcss_segment *seg;
 496
 497        if (!MACHINE_IS_VM)
 498                return;
 499
 500        mutex_lock(&dcss_lock);
 501        seg = segment_by_name (name);
 502        if (seg == NULL) {
 503                PRINT_ERR ("could not find segment %s in segment_unload, "
 504                                "please report to linux390@de.ibm.com\n",name);
 505                goto out_unlock;
 506        }
 507        if (atomic_dec_return(&seg->ref_count) != 0)
 508                goto out_unlock;
 509        release_resource(seg->res);
 510        kfree(seg->res);
 511        vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 512        list_del(&seg->list);
 513        dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
 514        kfree(seg);
 515out_unlock:
 516        mutex_unlock(&dcss_lock);
 517}
 518
 519/*
 520 * save segment content permanently
 521 */
 522void
 523segment_save(char *name)
 524{
 525        struct dcss_segment *seg;
 526        int startpfn = 0;
 527        int endpfn = 0;
 528        char cmd1[160];
 529        char cmd2[80];
 530        int i, response;
 531
 532        if (!MACHINE_IS_VM)
 533                return;
 534
 535        mutex_lock(&dcss_lock);
 536        seg = segment_by_name (name);
 537
 538        if (seg == NULL) {
 539                PRINT_ERR("could not find segment %s in segment_save, please "
 540                          "report to linux390@de.ibm.com\n", name);
 541                goto out;
 542        }
 543
 544        startpfn = seg->start_addr >> PAGE_SHIFT;
 545        endpfn = (seg->end) >> PAGE_SHIFT;
 546        sprintf(cmd1, "DEFSEG %s", name);
 547        for (i=0; i<seg->segcnt; i++) {
 548                sprintf(cmd1+strlen(cmd1), " %X-%X %s",
 549                        seg->range[i].start >> PAGE_SHIFT,
 550                        seg->range[i].end >> PAGE_SHIFT,
 551                        segtype_string[seg->range[i].start & 0xff]);
 552        }
 553        sprintf(cmd2, "SAVESEG %s", name);
 554        response = 0;
 555        cpcmd(cmd1, NULL, 0, &response);
 556        if (response) {
 557                PRINT_ERR("segment_save: DEFSEG failed with response code %i\n",
 558                          response);
 559                goto out;
 560        }
 561        cpcmd(cmd2, NULL, 0, &response);
 562        if (response) {
 563                PRINT_ERR("segment_save: SAVESEG failed with response code %i\n",
 564                          response);
 565                goto out;
 566        }
 567out:
 568        mutex_unlock(&dcss_lock);
 569}
 570
 571/*
 572 * print appropriate error message for segment_load()/segment_type()
 573 * return code
 574 */
 575void segment_warning(int rc, char *seg_name)
 576{
 577        switch (rc) {
 578        case -ENOENT:
 579                PRINT_WARN("cannot load/query segment %s, "
 580                           "does not exist\n", seg_name);
 581                break;
 582        case -ENOSYS:
 583                PRINT_WARN("cannot load/query segment %s, "
 584                           "not running on VM\n", seg_name);
 585                break;
 586        case -EIO:
 587                PRINT_WARN("cannot load/query segment %s, "
 588                           "hardware error\n", seg_name);
 589                break;
 590        case -ENOTSUPP:
 591                PRINT_WARN("cannot load/query segment %s, "
 592                           "is a multi-part segment\n", seg_name);
 593                break;
 594        case -ENOSPC:
 595                PRINT_WARN("cannot load/query segment %s, "
 596                           "overlaps with storage\n", seg_name);
 597                break;
 598        case -EBUSY:
 599                PRINT_WARN("cannot load/query segment %s, "
 600                           "overlaps with already loaded dcss\n", seg_name);
 601                break;
 602        case -EPERM:
 603                PRINT_WARN("cannot load/query segment %s, "
 604                           "already loaded in incompatible mode\n", seg_name);
 605                break;
 606        case -ENOMEM:
 607                PRINT_WARN("cannot load/query segment %s, "
 608                           "out of memory\n", seg_name);
 609                break;
 610        case -ERANGE:
 611                PRINT_WARN("cannot load/query segment %s, "
 612                           "exceeds kernel mapping range\n", seg_name);
 613                break;
 614        default:
 615                PRINT_WARN("cannot load/query segment %s, "
 616                           "return value %i\n", seg_name, rc);
 617                break;
 618        }
 619}
 620
 621EXPORT_SYMBOL(segment_load);
 622EXPORT_SYMBOL(segment_unload);
 623EXPORT_SYMBOL(segment_save);
 624EXPORT_SYMBOL(segment_type);
 625EXPORT_SYMBOL(segment_modify_shared);
 626EXPORT_SYMBOL(segment_warning);
 627