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 __init lmb_addrs_overlap(u64 base1, u64 size1,
  50                 u64 base2, u64 size2)
  51 {
  52         return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
  53 }
  54
  55 static long __init lmb_addrs_adjacent(u64 base1, u64 size1,
  56                 u64 base2, u64 size2)
  57 {
  58         if (base2 == base1 + size1)
  59                 return 1;
  60         else if (base1 == base2 + size2)
  61                 return -1;
  62
  63         return 0;
  64 }
  65
  66 static long __init lmb_regions_adjacent(struct lmb_region *rgn,
  67                 unsigned long r1, unsigned long r2)
  68 {
  69         u64 base1 = rgn->region[r1].base;
  70         u64 size1 = rgn->region[r1].size;
  71         u64 base2 = rgn->region[r2].base;
  72         u64 size2 = rgn->region[r2].size;
  73
  74         return lmb_addrs_adjacent(base1, size1, base2, size2);
  75 }
  76
  77 static void __init lmb_remove_region(struct lmb_region *rgn, unsigned long r)
  78 {
  79         unsigned long i;
  80
  81         for (i = r; i < rgn->cnt - 1; i++) {
  82                 rgn->region[i].base = rgn->region[i + 1].base;
  83                 rgn->region[i].size = rgn->region[i + 1].size;
  84         }
  85         rgn->cnt--;
  86 }
  87
  88 /* Assumption: base addr of region 1 < base addr of region 2 */
  89 static void __init lmb_coalesce_regions(struct lmb_region *rgn,
  90                 unsigned long r1, unsigned long r2)
  91 {
  92         rgn->region[r1].size += rgn->region[r2].size;
  93         lmb_remove_region(rgn, r2);
  94 }
  95
  96 void __init lmb_init(void)
  97 {
  98         /* Create a dummy zero size LMB which will get coalesced away later.
  99          * This simplifies the lmb_add() code below...
 100          */
 101         lmb.memory.region[0].base = 0;
 102         lmb.memory.region[0].size = 0;
 103         lmb.memory.cnt = 1;
 104
 105         /* Ditto. */
 106         lmb.reserved.region[0].base = 0;
 107         lmb.reserved.region[0].size = 0;
 108         lmb.reserved.cnt = 1;
 109 }
 110
 111 void __init lmb_analyze(void)
 112 {
 113         int i;
 114
 115         lmb.memory.size = 0;
 116
 117         for (i = 0; i < lmb.memory.cnt; i++)
 118                 lmb.memory.size += lmb.memory.region[i].size;
 119 }
 120
 121 static long __init lmb_add_region(struct lmb_region *rgn, u64 base, u64 size)
 122 {
 123         unsigned long coalesced = 0;
 124         long adjacent, i;
 125
 126         if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
 127                 rgn->region[0].base = base;
 128                 rgn->region[0].size = size;
 129                 return 0;
 130         }
 131
 132         /* First try and coalesce this LMB with another. */
 133         for (i = 0; i < rgn->cnt; i++) {
 134                 u64 rgnbase = rgn->region[i].base;
 135                 u64 rgnsize = rgn->region[i].size;
 136
 137                 if ((rgnbase == base) && (rgnsize == size))
 138                         /* Already have this region, so we're done */
 139                         return 0;
 140
 141                 adjacent = lmb_addrs_adjacent(base, size, rgnbase, rgnsize);
 142                 if (adjacent > 0) {
 143                         rgn->region[i].base -= size;
 144                         rgn->region[i].size += size;
 145                         coalesced++;
 146                         break;
 147                 } else if (adjacent < 0) {
 148                         rgn->region[i].size += size;
 149                         coalesced++;
 150                         break;
 151                 }
 152         }
 153
 154         if ((i < rgn->cnt - 1) && lmb_regions_adjacent(rgn, i, i+1)) {
 155                 lmb_coalesce_regions(rgn, i, i+1);
 156                 coalesced++;
 157         }
 158
 159         if (coalesced)
 160                 return coalesced;
 161         if (rgn->cnt >= MAX_LMB_REGIONS)
 162                 return -1;
 163
 164         /* Couldn't coalesce the LMB, so add it to the sorted table. */
 165         for (i = rgn->cnt - 1; i >= 0; i--) {
 166                 if (base < rgn->region[i].base) {
 167                         rgn->region[i+1].base = rgn->region[i].base;
 168                         rgn->region[i+1].size = rgn->region[i].size;
 169                 } else {
 170                         rgn->region[i+1].base = base;
 171                         rgn->region[i+1].size = size;
 172                         break;
 173                 }
 174         }
 175
 176         if (base < rgn->region[0].base) {
 177                 rgn->region[0].base = base;
 178                 rgn->region[0].size = size;
 179         }
 180         rgn->cnt++;
 181
 182         return 0;
 183 }
 184
 185 long __init lmb_add(u64 base, u64 size)
 186 {
 187         struct lmb_region *_rgn = &lmb.memory;
 188
 189         /* On pSeries LPAR systems, the first LMB is our RMO region. */
 190         if (base == 0)
 191                 lmb.rmo_size = size;
 192
 193         return lmb_add_region(_rgn, base, size);
 194
 195 }
 196
 197 long __init lmb_reserve(u64 base, u64 size)
 198 {
 199         struct lmb_region *_rgn = &lmb.reserved;
 200
 201         BUG_ON(0 == size);
 202
 203         return lmb_add_region(_rgn, base, size);
 204 }
 205
 206 long __init lmb_overlaps_region(struct lmb_region *rgn, u64 base, u64 size)
 207 {
 208         unsigned long i;
 209
 210         for (i = 0; i < rgn->cnt; i++) {
 211                 u64 rgnbase = rgn->region[i].base;
 212                 u64 rgnsize = rgn->region[i].size;
 213                 if (lmb_addrs_overlap(base, size, rgnbase, rgnsize))
 214                         break;
 215         }
 216
 217         return (i < rgn->cnt) ? i : -1;
 218 }
 219
 220 static u64 lmb_align_down(u64 addr, u64 size)
 221 {
 222         return addr & ~(size - 1);
 223 }
 224
 225 static u64 lmb_align_up(u64 addr, u64 size)
 226 {
 227         return (addr + (size - 1)) & ~(size - 1);
 228 }
 229
 230 static u64 __init lmb_alloc_nid_unreserved(u64 start, u64 end,
 231                                            u64 size, u64 align)
 232 {
 233         u64 base, res_base;
 234         long j;
 235
 236         base = lmb_align_down((end - size), align);
 237         while (start <= base) {
 238                 j = lmb_overlaps_region(&lmb.reserved, base, size);
 239                 if (j < 0) {
 240                         /* this area isn't reserved, take it */
 241                         if (lmb_add_region(&lmb.reserved, base,
 242                                            lmb_align_up(size, align)) < 0)
 243                                 base = ~(u64)0;
 244                         return base;
 245                 }
 246                 res_base = lmb.reserved.region[j].base;
 247                 if (res_base < size)
 248                         break;
 249                 base = lmb_align_down(res_base - size, align);
 250         }
 251
 252         return ~(u64)0;
 253 }
 254
 255 static u64 __init lmb_alloc_nid_region(struct lmb_property *mp,
 256                                        u64 (*nid_range)(u64, u64, int *),
 257                                        u64 size, u64 align, int nid)
 258 {
 259         u64 start, end;
 260
 261         start = mp->base;
 262         end = start + mp->size;
 263
 264         start = lmb_align_up(start, align);
 265         while (start < end) {
 266                 u64 this_end;
 267                 int this_nid;
 268
 269                 this_end = nid_range(start, end, &this_nid);
 270                 if (this_nid == nid) {
 271                         u64 ret = lmb_alloc_nid_unreserved(start, this_end,
 272                                                            size, align);
 273                         if (ret != ~(u64)0)
 274                                 return ret;
 275                 }
 276                 start = this_end;
 277         }
 278
 279         return ~(u64)0;
 280 }
 281
 282 u64 __init lmb_alloc_nid(u64 size, u64 align, int nid,
 283                          u64 (*nid_range)(u64 start, u64 end, int *nid))
 284 {
 285         struct lmb_region *mem = &lmb.memory;
 286         int i;
 287
 288         for (i = 0; i < mem->cnt; i++) {
 289                 u64 ret = lmb_alloc_nid_region(&mem->region[i],
 290                                                nid_range,
 291                                                size, align, nid);
 292                 if (ret != ~(u64)0)
 293                         return ret;
 294         }
 295
 296         return lmb_alloc(size, align);
 297 }
 298
 299 u64 __init lmb_alloc(u64 size, u64 align)
 300 {
 301         return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
 302 }
 303
 304 u64 __init lmb_alloc_base(u64 size, u64 align, u64 max_addr)
 305 {
 306         u64 alloc;
 307
 308         alloc = __lmb_alloc_base(size, align, max_addr);
 309
 310         if (alloc == 0)
 311                 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
 312                       (unsigned long long) size, (unsigned long long) max_addr);
 313
 314         return alloc;
 315 }
 316
 317 u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
 318 {
 319         long i, j;
 320         u64 base = 0;
 321         u64 res_base;
 322
 323         BUG_ON(0 == size);
 324
 325         /* On some platforms, make sure we allocate lowmem */
 326         /* Note that LMB_REAL_LIMIT may be LMB_ALLOC_ANYWHERE */
 327         if (max_addr == LMB_ALLOC_ANYWHERE)
 328                 max_addr = LMB_REAL_LIMIT;
 329
 330         for (i = lmb.memory.cnt - 1; i >= 0; i--) {
 331                 u64 lmbbase = lmb.memory.region[i].base;
 332                 u64 lmbsize = lmb.memory.region[i].size;
 333
 334                 if (lmbsize < size)
 335                         continue;
 336                 if (max_addr == LMB_ALLOC_ANYWHERE)
 337                         base = lmb_align_down(lmbbase + lmbsize - size, align);
 338                 else if (lmbbase < max_addr) {
 339                         base = min(lmbbase + lmbsize, max_addr);
 340                         base = lmb_align_down(base - size, align);
 341                 } else
 342                         continue;
 343
 344                 while (base && lmbbase <= base) {
 345                         j = lmb_overlaps_region(&lmb.reserved, base, size);
 346                         if (j < 0) {
 347                                 /* this area isn't reserved, take it */
 348                                 if (lmb_add_region(&lmb.reserved, base,
 349                                                    size) < 0)
 350                                         return 0;
 351                                 return base;
 352                         }
 353                         res_base = lmb.reserved.region[j].base;
 354                         if (res_base < size)
 355                                 break;
 356                         base = lmb_align_down(res_base - size, align);
 357                 }
 358         }
 359         return 0;
 360 }
 361
 362 /* You must call lmb_analyze() before this. */
 363 u64 __init lmb_phys_mem_size(void)
 364 {
 365         return lmb.memory.size;
 366 }
 367
 368 u64 __init lmb_end_of_DRAM(void)
 369 {
 370         int idx = lmb.memory.cnt - 1;
 371
 372         return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
 373 }
 374
 375 /* You must call lmb_analyze() after this. */
 376 void __init lmb_enforce_memory_limit(u64 memory_limit)
 377 {
 378         unsigned long i;
 379         u64 limit;
 380         struct lmb_property *p;
 381
 382         if (!memory_limit)
 383                 return;
 384
 385         /* Truncate the lmb regions to satisfy the memory limit. */
 386         limit = memory_limit;
 387         for (i = 0; i < lmb.memory.cnt; i++) {
 388                 if (limit > lmb.memory.region[i].size) {
 389                         limit -= lmb.memory.region[i].size;
 390                         continue;
 391                 }
 392
 393                 lmb.memory.region[i].size = limit;
 394                 lmb.memory.cnt = i + 1;
 395                 break;
 396         }
 397
 398         if (lmb.memory.region[0].size < lmb.rmo_size)
 399                 lmb.rmo_size = lmb.memory.region[0].size;
 400
 401         /* And truncate any reserves above the limit also. */
 402         for (i = 0; i < lmb.reserved.cnt; i++) {
 403                 p = &lmb.reserved.region[i];
 404
 405                 if (p->base > memory_limit)
 406                         p->size = 0;
 407                 else if ((p->base + p->size) > memory_limit)
 408                         p->size = memory_limit - p->base;
 409
 410                 if (p->size == 0) {
 411                         lmb_remove_region(&lmb.reserved, i);
 412                         i--;
 413                 }
 414         }
 415 }
 416
 417 int __init lmb_is_reserved(u64 addr)
 418 {
 419         int i;
 420
 421         for (i = 0; i < lmb.reserved.cnt; i++) {
 422                 u64 upper = lmb.reserved.region[i].base +
 423                         lmb.reserved.region[i].size - 1;
 424                 if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
 425                         return 1;
 426         }
 427         return 0;
 428 }