lib/lmb.c

   1 /*
   2  * Procedures for maintaining information about logical memory blocks.
   3  *
   4  * Peter Bergner, IBM Corp.     June 2001.
   5  * Copyright (C) 2001 Peter Bergner.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/bitops.h>
  16 #include <linux/lmb.h>
  17
  18 #define LMB_ALLOC_ANYWHERE      0
  19
  20 struct lmb lmb;
  21
  22 static int lmb_debug;
  23
  24 static int __init early_lmb(char *p)
  25 {
  26         if (p && strstr(p, "debug"))
  27                 lmb_debug = 1;
  28         return 0;
  29 }
  30 early_param("lmb", early_lmb);
  31
  32 void lmb_dump_all(void)
  33 {
  34         unsigned long i;
  35
  36         if (!lmb_debug)
  37                 return;
  38
  39         pr_info("lmb_dump_all:\n");
  40         pr_info("    memory.cnt           = 0x%lx\n", lmb.memory.cnt);
  41         pr_info("    memory.size                  = 0x%llx\n",
  42             (unsigned long long)lmb.memory.size);
  43         for (i=0; i < lmb.memory.cnt ;i++) {
  44                 pr_info("    memory.region[0x%lx].base       = 0x%llx\n",
  45                     i, (unsigned long long)lmb.memory.region[i].base);
  46                 pr_info("                     .size     = 0x%llx\n",
  47                     (unsigned long long)lmb.memory.region[i].size);
  48         }
  49
  50         pr_info("    reserved.cnt         = 0x%lx\n", lmb.reserved.cnt);
  51         pr_info("    reserved.size        = 0x%llx\n",
  52             (unsigned long long)lmb.memory.size);
  53         for (i=0; i < lmb.reserved.cnt ;i++) {
  54                 pr_info("    reserved.region[0x%lx].base       = 0x%llx\n",
  55                     i, (unsigned long long)lmb.reserved.region[i].base);
  56                 pr_info("                     .size     = 0x%llx\n",
  57                     (unsigned long long)lmb.reserved.region[i].size);
  58         }
  59 }
  60
  61 static unsigned long lmb_addrs_overlap(u64 base1, u64 size1, u64 base2,
  62                                         u64 size2)
  63 {
  64         return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
  65 }
  66
  67 static long lmb_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
  68 {
  69         if (base2 == base1 + size1)
  70                 return 1;
  71         else if (base1 == base2 + size2)
  72                 return -1;
  73
  74         return 0;
  75 }
  76
  77 static long lmb_regions_adjacent(struct lmb_region *rgn,
  78                 unsigned long r1, unsigned long r2)
  79 {
  80         u64 base1 = rgn->region[r1].base;
  81         u64 size1 = rgn->region[r1].size;
  82         u64 base2 = rgn->region[r2].base;
  83         u64 size2 = rgn->region[r2].size;
  84
  85         return lmb_addrs_adjacent(base1, size1, base2, size2);
  86 }
  87
  88 static void lmb_remove_region(struct lmb_region *rgn, unsigned long r)
  89 {
  90         unsigned long i;
  91
  92         for (i = r; i < rgn->cnt - 1; i++) {
  93                 rgn->region[i].base = rgn->region[i + 1].base;
  94                 rgn->region[i].size = rgn->region[i + 1].size;
  95         }
  96         rgn->cnt--;
  97 }
  98
  99 /* Assumption: base addr of region 1 < base addr of region 2 */
 100 static void lmb_coalesce_regions(struct lmb_region *rgn,
 101                 unsigned long r1, unsigned long r2)
 102 {
 103         rgn->region[r1].size += rgn->region[r2].size;
 104         lmb_remove_region(rgn, r2);
 105 }
 106
 107 void __init lmb_init(void)
 108 {
 109         /* Create a dummy zero size LMB which will get coalesced away later.
 110          * This simplifies the lmb_add() code below...
 111          */
 112         lmb.memory.region[0].base = 0;
 113         lmb.memory.region[0].size = 0;
 114         lmb.memory.cnt = 1;
 115
 116         /* Ditto. */
 117         lmb.reserved.region[0].base = 0;
 118         lmb.reserved.region[0].size = 0;
 119         lmb.reserved.cnt = 1;
 120 }
 121
 122 void __init lmb_analyze(void)
 123 {
 124         int i;
 125
 126         lmb.memory.size = 0;
 127
 128         for (i = 0; i < lmb.memory.cnt; i++)
 129                 lmb.memory.size += lmb.memory.region[i].size;
 130 }
 131
 132 static long lmb_add_region(struct lmb_region *rgn, u64 base, u64 size)
 133 {
 134         unsigned long coalesced = 0;
 135         long adjacent, i;
 136
 137         if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
 138                 rgn->region[0].base = base;
 139                 rgn->region[0].size = size;
 140                 return 0;
 141         }
 142
 143         /* First try and coalesce this LMB with another. */
 144         for (i = 0; i < rgn->cnt; i++) {
 145                 u64 rgnbase = rgn->region[i].base;
 146                 u64 rgnsize = rgn->region[i].size;
 147
 148                 if ((rgnbase == base) && (rgnsize == size))
 149                         /* Already have this region, so we're done */
 150                         return 0;
 151
 152                 adjacent = lmb_addrs_adjacent(base, size, rgnbase, rgnsize);
 153                 if (adjacent > 0) {
 154                         rgn->region[i].base -= size;
 155                         rgn->region[i].size += size;
 156                         coalesced++;
 157                         break;
 158                 } else if (adjacent < 0) {
 159                         rgn->region[i].size += size;
 160                         coalesced++;
 161                         break;
 162                 }
 163         }
 164
 165         if ((i < rgn->cnt - 1) && lmb_regions_adjacent(rgn, i, i+1)) {
 166                 lmb_coalesce_regions(rgn, i, i+1);
 167                 coalesced++;
 168         }
 169
 170         if (coalesced)
 171                 return coalesced;
 172         if (rgn->cnt >= MAX_LMB_REGIONS)
 173                 return -1;
 174
 175         /* Couldn't coalesce the LMB, so add it to the sorted table. */
 176         for (i = rgn->cnt - 1; i >= 0; i--) {
 177                 if (base < rgn->region[i].base) {
 178                         rgn->region[i+1].base = rgn->region[i].base;
 179                         rgn->region[i+1].size = rgn->region[i].size;
 180                 } else {
 181                         rgn->region[i+1].base = base;
 182                         rgn->region[i+1].size = size;
 183                         break;
 184                 }
 185         }
 186
 187         if (base < rgn->region[0].base) {
 188                 rgn->region[0].base = base;
 189                 rgn->region[0].size = size;
 190         }
 191         rgn->cnt++;
 192
 193         return 0;
 194 }
 195
 196 long lmb_add(u64 base, u64 size)
 197 {
 198         struct lmb_region *_rgn = &lmb.memory;
 199
 200         /* On pSeries LPAR systems, the first LMB is our RMO region. */
 201         if (base == 0)
 202                 lmb.rmo_size = size;
 203
 204         return lmb_add_region(_rgn, base, size);
 205
 206 }
 207
 208 long lmb_remove(u64 base, u64 size)
 209 {
 210         struct lmb_region *rgn = &(lmb.memory);
 211         u64 rgnbegin, rgnend;
 212         u64 end = base + size;
 213         int i;
 214
 215         rgnbegin = rgnend = 0; /* supress gcc warnings */
 216
 217         /* Find the region where (base, size) belongs to */
 218         for (i=0; i < rgn->cnt; i++) {
 219                 rgnbegin = rgn->region[i].base;
 220                 rgnend = rgnbegin + rgn->region[i].size;
 221
 222                 if ((rgnbegin <= base) && (end <= rgnend))
 223                         break;
 224         }
 225
 226         /* Didn't find the region */
 227         if (i == rgn->cnt)
 228                 return -1;
 229
 230         /* Check to see if we are removing entire region */
 231         if ((rgnbegin == base) && (rgnend == end)) {
 232                 lmb_remove_region(rgn, i);
 233                 return 0;
 234         }
 235
 236         /* Check to see if region is matching at the front */
 237         if (rgnbegin == base) {
 238                 rgn->region[i].base = end;
 239                 rgn->region[i].size -= size;
 240                 return 0;
 241         }
 242
 243         /* Check to see if the region is matching at the end */
 244         if (rgnend == end) {
 245                 rgn->region[i].size -= size;
 246                 return 0;
 247         }
 248
 249         /*
 250          * We need to split the entry -  adjust the current one to the
 251          * beginging of the hole and add the region after hole.
 252          */
 253         rgn->region[i].size = base - rgn->region[i].base;
 254         return lmb_add_region(rgn, end, rgnend - end);
 255 }
 256
 257 long __init lmb_reserve(u64 base, u64 size)
 258 {
 259         struct lmb_region *_rgn = &lmb.reserved;
 260
 261         BUG_ON(0 == size);
 262
 263         return lmb_add_region(_rgn, base, size);
 264 }
 265
 266 long __init lmb_overlaps_region(struct lmb_region *rgn, u64 base, u64 size)
 267 {
 268         unsigned long i;
 269
 270         for (i = 0; i < rgn->cnt; i++) {
 271                 u64 rgnbase = rgn->region[i].base;
 272                 u64 rgnsize = rgn->region[i].size;
 273                 if (lmb_addrs_overlap(base, size, rgnbase, rgnsize))
 274                         break;
 275         }
 276
 277         return (i < rgn->cnt) ? i : -1;
 278 }
 279
 280 static u64 lmb_align_down(u64 addr, u64 size)
 281 {
 282         return addr & ~(size - 1);
 283 }
 284
 285 static u64 lmb_align_up(u64 addr, u64 size)
 286 {
 287         return (addr + (size - 1)) & ~(size - 1);
 288 }
 289
 290 static u64 __init lmb_alloc_nid_unreserved(u64 start, u64 end,
 291                                            u64 size, u64 align)
 292 {
 293         u64 base, res_base;
 294         long j;
 295
 296         base = lmb_align_down((end - size), align);
 297         while (start <= base) {
 298                 j = lmb_overlaps_region(&lmb.reserved, base, size);
 299                 if (j < 0) {
 300                         /* this area isn't reserved, take it */
 301                         if (lmb_add_region(&lmb.reserved, base, size) < 0)
 302                                 base = ~(u64)0;
 303                         return base;
 304                 }
 305                 res_base = lmb.reserved.region[j].base;
 306                 if (res_base < size)
 307                         break;
 308                 base = lmb_align_down(res_base - size, align);
 309         }
 310
 311         return ~(u64)0;
 312 }
 313
 314 static u64 __init lmb_alloc_nid_region(struct lmb_property *mp,
 315                                        u64 (*nid_range)(u64, u64, int *),
 316                                        u64 size, u64 align, int nid)
 317 {
 318         u64 start, end;
 319
 320         start = mp->base;
 321         end = start + mp->size;
 322
 323         start = lmb_align_up(start, align);
 324         while (start < end) {
 325                 u64 this_end;
 326                 int this_nid;
 327
 328                 this_end = nid_range(start, end, &this_nid);
 329                 if (this_nid == nid) {
 330                         u64 ret = lmb_alloc_nid_unreserved(start, this_end,
 331                                                            size, align);
 332                         if (ret != ~(u64)0)
 333                                 return ret;
 334                 }
 335                 start = this_end;
 336         }
 337
 338         return ~(u64)0;
 339 }
 340
 341 u64 __init lmb_alloc_nid(u64 size, u64 align, int nid,
 342                          u64 (*nid_range)(u64 start, u64 end, int *nid))
 343 {
 344         struct lmb_region *mem = &lmb.memory;
 345         int i;
 346
 347         BUG_ON(0 == size);
 348
 349         size = lmb_align_up(size, align);
 350
 351         for (i = 0; i < mem->cnt; i++) {
 352                 u64 ret = lmb_alloc_nid_region(&mem->region[i],
 353                                                nid_range,
 354                                                size, align, nid);
 355                 if (ret != ~(u64)0)
 356                         return ret;
 357         }
 358
 359         return lmb_alloc(size, align);
 360 }
 361
 362 u64 __init lmb_alloc(u64 size, u64 align)
 363 {
 364         return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
 365 }
 366
 367 u64 __init lmb_alloc_base(u64 size, u64 align, u64 max_addr)
 368 {
 369         u64 alloc;
 370
 371         alloc = __lmb_alloc_base(size, align, max_addr);
 372
 373         if (alloc == 0)
 374                 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
 375                       (unsigned long long) size, (unsigned long long) max_addr);
 376
 377         return alloc;
 378 }
 379
 380 u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
 381 {
 382         long i, j;
 383         u64 base = 0;
 384         u64 res_base;
 385
 386         BUG_ON(0 == size);
 387
 388         size = lmb_align_up(size, align);
 389
 390         /* On some platforms, make sure we allocate lowmem */
 391         /* Note that LMB_REAL_LIMIT may be LMB_ALLOC_ANYWHERE */
 392         if (max_addr == LMB_ALLOC_ANYWHERE)
 393                 max_addr = LMB_REAL_LIMIT;
 394
 395         for (i = lmb.memory.cnt - 1; i >= 0; i--) {
 396                 u64 lmbbase = lmb.memory.region[i].base;
 397                 u64 lmbsize = lmb.memory.region[i].size;
 398
 399                 if (lmbsize < size)
 400                         continue;
 401                 if (max_addr == LMB_ALLOC_ANYWHERE)
 402                         base = lmb_align_down(lmbbase + lmbsize - size, align);
 403                 else if (lmbbase < max_addr) {
 404                         base = min(lmbbase + lmbsize, max_addr);
 405                         base = lmb_align_down(base - size, align);
 406                 } else
 407                         continue;
 408
 409                 while (base && lmbbase <= base) {
 410                         j = lmb_overlaps_region(&lmb.reserved, base, size);
 411                         if (j < 0) {
 412                                 /* this area isn't reserved, take it */
 413                                 if (lmb_add_region(&lmb.reserved, base, size) < 0)
 414                                         return 0;
 415                                 return base;
 416                         }
 417                         res_base = lmb.reserved.region[j].base;
 418                         if (res_base < size)
 419                                 break;
 420                         base = lmb_align_down(res_base - size, align);
 421                 }
 422         }
 423         return 0;
 424 }
 425
 426 /* You must call lmb_analyze() before this. */
 427 u64 __init lmb_phys_mem_size(void)
 428 {
 429         return lmb.memory.size;
 430 }
 431
 432 u64 __init lmb_end_of_DRAM(void)
 433 {
 434         int idx = lmb.memory.cnt - 1;
 435
 436         return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
 437 }
 438
 439 /* You must call lmb_analyze() after this. */
 440 void __init lmb_enforce_memory_limit(u64 memory_limit)
 441 {
 442         unsigned long i;
 443         u64 limit;
 444         struct lmb_property *p;
 445
 446         if (!memory_limit)
 447                 return;
 448
 449         /* Truncate the lmb regions to satisfy the memory limit. */
 450         limit = memory_limit;
 451         for (i = 0; i < lmb.memory.cnt; i++) {
 452                 if (limit > lmb.memory.region[i].size) {
 453                         limit -= lmb.memory.region[i].size;
 454                         continue;
 455                 }
 456
 457                 lmb.memory.region[i].size = limit;
 458                 lmb.memory.cnt = i + 1;
 459                 break;
 460         }
 461
 462         if (lmb.memory.region[0].size < lmb.rmo_size)
 463                 lmb.rmo_size = lmb.memory.region[0].size;
 464
 465         memory_limit = lmb_end_of_DRAM();
 466
 467         /* And truncate any reserves above the limit also. */
 468         for (i = 0; i < lmb.reserved.cnt; i++) {
 469                 p = &lmb.reserved.region[i];
 470
 471                 if (p->base > memory_limit)
 472                         p->size = 0;
 473                 else if ((p->base + p->size) > memory_limit)
 474                         p->size = memory_limit - p->base;
 475
 476                 if (p->size == 0) {
 477                         lmb_remove_region(&lmb.reserved, i);
 478                         i--;
 479                 }
 480         }
 481 }
 482
 483 int __init lmb_is_reserved(u64 addr)
 484 {
 485         int i;
 486
 487         for (i = 0; i < lmb.reserved.cnt; i++) {
 488                 u64 upper = lmb.reserved.region[i].base +
 489                         lmb.reserved.region[i].size - 1;
 490                 if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
 491                         return 1;
 492         }
 493         return 0;
 494 }
 495
 496 /*
 497  * Given a <base, len>, find which memory regions belong to this range.
 498  * Adjust the request and return a contiguous chunk.
 499  */
 500 int lmb_find(struct lmb_property *res)
 501 {
 502         int i;
 503         u64 rstart, rend;
 504
 505         rstart = res->base;
 506         rend = rstart + res->size - 1;
 507
 508         for (i = 0; i < lmb.memory.cnt; i++) {
 509                 u64 start = lmb.memory.region[i].base;
 510                 u64 end = start + lmb.memory.region[i].size - 1;
 511
 512                 if (start > rend)
 513                         return -1;
 514
 515                 if ((end >= rstart) && (start < rend)) {
 516                         /* adjust the request */
 517                         if (rstart < start)
 518                                 rstart = start;
 519                         if (rend > end)
 520                                 rend = end;
 521                         res->base = rstart;
 522                         res->size = rend - rstart + 1;
 523                         return 0;
 524                 }
 525         }
 526         return -1;
 527 }