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