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