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 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 kfree(qin); 238 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, NULL); 580 cpcmd(cmd2, NULL, 0, NULL); 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); 589