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 #undef DEBUG
  19
  20 #ifdef DEBUG
  21 #define DBG(fmt...) LMB_DBG(fmt)
  22 #else
  23 #define DBG(fmt...)
  24 #endif
  25
  26 #define LMB_ALLOC_ANYWHERE      0
  27
  28 struct lmb lmb;
  29
  30 void lmb_dump_all(void)
  31 {
  32 #ifdef DEBUG
  33         unsigned long i;
  34
  35         DBG("lmb_dump_all:\n");
  36         DBG("    memory.cnt               = 0x%lx\n", lmb.memory.cnt);
  37         DBG("    memory.size              = 0x%llx\n",
  38             (unsigned long long)lmb.memory.size);
  39         for (i=0; i < lmb.memory.cnt ;i++) {
  40                 DBG("    memory.region[0x%x].base       = 0x%llx\n",
  41                     i, (unsigned long long)lmb.memory.region[i].base);
  42                 DBG("                 .size     = 0x%llx\n",
  43                     (unsigned long long)lmb.memory.region[i].size);
  44         }
  45
  46         DBG("\n    reserved.cnt   = 0x%lx\n", lmb.reserved.cnt);
  47         DBG("    reserved.size    = 0x%lx\n", lmb.reserved.size);
  48         for (i=0; i < lmb.reserved.cnt ;i++) {
  49                 DBG("    reserved.region[0x%x].base       = 0x%llx\n",
  50                     i, (unsigned long long)lmb.reserved.region[i].base);
  51                 DBG("                 .size     = 0x%llx\n",
  52                     (unsigned long long)lmb.reserved.region[i].size);
  53         }
  54 #endif /* DEBUG */
  55 }
  56
  57 static unsigned long __init lmb_addrs_overlap(u64 base1,
  58                 u64 size1, u64 base2, u64 size2)
  59 {
  60         return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
  61 }
  62
  63 static long __init lmb_addrs_adjacent(u64 base1, u64 size1,
  64                 u64 base2, u64 size2)
  65 {
  66         if (base2 == base1 + size1)
  67                 return 1;
  68         else if (base1 == base2 + size2)
  69                 return -1;
  70
  71         return 0;
  72 }
  73
  74 static long __init lmb_regions_adjacent(struct lmb_region *rgn,
  75                 unsigned long r1, unsigned long r2)
  76 {
  77         u64 base1 = rgn->region[r1].base;
  78         u64 size1 = rgn->region[r1].size;
  79         u64 base2 = rgn->region[r2].base;
  80         u64 size2 = rgn->region[r2].size;
  81
  82         return lmb_addrs_adjacent(base1, size1, base2, size2);
  83 }
  84
  85 static void __init lmb_remove_region(struct lmb_region *rgn, unsigned long r)
  86 {
  87         unsigned long i;
  88
  89         for (i = r; i < rgn->cnt - 1; i++) {
  90                 rgn->region[i].base = rgn->region[i + 1].base;
  91                 rgn->region[i].size = rgn->region[i + 1].size;
  92         }
  93         rgn->cnt--;
  94 }
  95
  96 /* Assumption: base addr of region 1 < base addr of region 2 */
  97 static void __init lmb_coalesce_regions(struct lmb_region *rgn,
  98                 unsigned long r1, unsigned long r2)
  99 {
 100         rgn->region[r1].size += rgn->region[r2].size;
 101         lmb_remove_region(rgn, r2);
 102 }
 103
 104 /* This routine called with relocation disabled. */
 105 void __init lmb_init(void)
 106 {
 107         /* Create a dummy zero size LMB which will get coalesced away later.
 108          * This simplifies the lmb_add() code below...
 109          */
 110         lmb.memory.region[0].base = 0;
 111         lmb.memory.region[0].size = 0;
 112         lmb.memory.cnt = 1;
 113
 114         /* Ditto. */
 115         lmb.reserved.region[0].base = 0;
 116         lmb.reserved.region[0].size = 0;
 117         lmb.reserved.cnt = 1;
 118 }
 119
 120 /* This routine may be called with relocation disabled. */
 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 /* This routine called with relocation disabled. */
 132 static long __init 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                 }
 159                 else if ( adjacent < 0 ) {
 160                         rgn->region[i].size += size;
 161                         coalesced++;
 162                         break;
 163                 }
 164         }
 165
 166         if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
 167                 lmb_coalesce_regions(rgn, i, i+1);
 168                 coalesced++;
 169         }
 170
 171         if (coalesced)
 172                 return coalesced;
 173         if (rgn->cnt >= MAX_LMB_REGIONS)
 174                 return -1;
 175
 176         /* Couldn't coalesce the LMB, so add it to the sorted table. */
 177         for (i = rgn->cnt-1; i >= 0; i--) {
 178                 if (base < rgn->region[i].base) {
 179                         rgn->region[i+1].base = rgn->region[i].base;
 180                         rgn->region[i+1].size = rgn->region[i].size;
 181                 } else {
 182                         rgn->region[i+1].base = base;
 183                         rgn->region[i+1].size = size;
 184                         break;
 185                 }
 186         }
 187         rgn->cnt++;
 188
 189         return 0;
 190 }
 191
 192 /* This routine may be called with relocation disabled. */
 193 long __init lmb_add(u64 base, u64 size)
 194 {
 195         struct lmb_region *_rgn = &(lmb.memory);
 196
 197         /* On pSeries LPAR systems, the first LMB is our RMO region. */
 198         if (base == 0)
 199                 lmb.rmo_size = size;
 200
 201         return lmb_add_region(_rgn, base, size);
 202
 203 }
 204
 205 long __init lmb_reserve(u64 base, u64 size)
 206 {
 207         struct lmb_region *_rgn = &(lmb.reserved);
 208
 209         BUG_ON(0 == size);
 210
 211         return lmb_add_region(_rgn, base, size);
 212 }
 213
 214 long __init lmb_overlaps_region(struct lmb_region *rgn, u64 base,
 215                                 u64 size)
 216 {
 217         unsigned long i;
 218
 219         for (i=0; i < rgn->cnt; i++) {
 220                 u64 rgnbase = rgn->region[i].base;
 221                 u64 rgnsize = rgn->region[i].size;
 222                 if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
 223                         break;
 224                 }
 225         }
 226
 227         return (i < rgn->cnt) ? i : -1;
 228 }
 229
 230 u64 __init lmb_alloc(u64 size, u64 align)
 231 {
 232         return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
 233 }
 234
 235 u64 __init lmb_alloc_base(u64 size, u64 align, u64 max_addr)
 236 {
 237         u64 alloc;
 238
 239         alloc = __lmb_alloc_base(size, align, max_addr);
 240
 241         if (alloc == 0)
 242                 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
 243                       (unsigned long long) size, (unsigned long long) max_addr);
 244
 245         return alloc;
 246 }
 247
 248 static u64 lmb_align_down(u64 addr, u64 size)
 249 {
 250         return addr & ~(size - 1);
 251 }
 252
 253 static u64 lmb_align_up(u64 addr, u64 size)
 254 {
 255         return (addr + (size - 1)) & ~(size - 1);
 256 }
 257
 258 u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
 259 {
 260         long i, j;
 261         u64 base = 0;
 262
 263         BUG_ON(0 == size);
 264
 265         /* On some platforms, make sure we allocate lowmem */
 266         if (max_addr == LMB_ALLOC_ANYWHERE)
 267                 max_addr = LMB_REAL_LIMIT;
 268
 269         for (i = lmb.memory.cnt-1; i >= 0; i--) {
 270                 u64 lmbbase = lmb.memory.region[i].base;
 271                 u64 lmbsize = lmb.memory.region[i].size;
 272
 273                 if (max_addr == LMB_ALLOC_ANYWHERE)
 274                         base = lmb_align_down(lmbbase + lmbsize - size, align);
 275                 else if (lmbbase < max_addr) {
 276                         base = min(lmbbase + lmbsize, max_addr);
 277                         base = lmb_align_down(base - size, align);
 278                 } else
 279                         continue;
 280
 281                 while ((lmbbase <= base) &&
 282                        ((j = lmb_overlaps_region(&lmb.reserved, base, size)) >= 0) )
 283                         base = lmb_align_down(lmb.reserved.region[j].base - size,
 284                                               align);
 285
 286                 if ((base != 0) && (lmbbase <= base))
 287                         break;
 288         }
 289
 290         if (i < 0)
 291                 return 0;
 292
 293         if (lmb_add_region(&lmb.reserved, base, lmb_align_up(size, align)) < 0)
 294                 return 0;
 295
 296         return base;
 297 }
 298
 299 /* You must call lmb_analyze() before this. */
 300 u64 __init lmb_phys_mem_size(void)
 301 {
 302         return lmb.memory.size;
 303 }
 304
 305 u64 __init lmb_end_of_DRAM(void)
 306 {
 307         int idx = lmb.memory.cnt - 1;
 308
 309         return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
 310 }
 311
 312 /* You must call lmb_analyze() after this. */
 313 void __init lmb_enforce_memory_limit(u64 memory_limit)
 314 {
 315         unsigned long i;
 316         u64 limit;
 317         struct lmb_property *p;
 318
 319         if (! memory_limit)
 320                 return;
 321
 322         /* Truncate the lmb regions to satisfy the memory limit. */
 323         limit = memory_limit;
 324         for (i = 0; i < lmb.memory.cnt; i++) {
 325                 if (limit > lmb.memory.region[i].size) {
 326                         limit -= lmb.memory.region[i].size;
 327                         continue;
 328                 }
 329
 330                 lmb.memory.region[i].size = limit;
 331                 lmb.memory.cnt = i + 1;
 332                 break;
 333         }
 334
 335         if (lmb.memory.region[0].size < lmb.rmo_size)
 336                 lmb.rmo_size = lmb.memory.region[0].size;
 337
 338         /* And truncate any reserves above the limit also. */
 339         for (i = 0; i < lmb.reserved.cnt; i++) {
 340                 p = &lmb.reserved.region[i];
 341
 342                 if (p->base > memory_limit)
 343                         p->size = 0;
 344                 else if ((p->base + p->size) > memory_limit)
 345                         p->size = memory_limit - p->base;
 346
 347                 if (p->size == 0) {
 348                         lmb_remove_region(&lmb.reserved, i);
 349                         i--;
 350                 }
 351         }
 352 }
 353
 354 int __init lmb_is_reserved(u64 addr)
 355 {
 356         int i;
 357
 358         for (i = 0; i < lmb.reserved.cnt; i++) {
 359                 u64 upper = lmb.reserved.region[i].base +
 360                         lmb.reserved.region[i].size - 1;
 361                 if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
 362                         return 1;
 363         }
 364         return 0;
 365 }