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%lx\n", lmb.memory.size);
  38         for (i=0; i < lmb.memory.cnt ;i++) {
  39                 DBG("    memory.region[0x%x].base       = 0x%lx\n",
  40                             i, lmb.memory.region[i].base);
  41                 DBG("                 .size     = 0x%lx\n",
  42                             lmb.memory.region[i].size);
  43         }
  44
  45         DBG("\n    reserved.cnt   = 0x%lx\n", lmb.reserved.cnt);
  46         DBG("    reserved.size    = 0x%lx\n", lmb.reserved.size);
  47         for (i=0; i < lmb.reserved.cnt ;i++) {
  48                 DBG("    reserved.region[0x%x].base       = 0x%lx\n",
  49                             i, lmb.reserved.region[i].base);
  50                 DBG("                 .size     = 0x%lx\n",
  51                             lmb.reserved.region[i].size);
  52         }
  53 #endif /* DEBUG */
  54 }
  55
  56 static unsigned long __init lmb_addrs_overlap(unsigned long base1,
  57                 unsigned long size1, unsigned long base2, unsigned long size2)
  58 {
  59         return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
  60 }
  61
  62 static long __init lmb_addrs_adjacent(unsigned long base1, unsigned long size1,
  63                 unsigned long base2, unsigned long size2)
  64 {
  65         if (base2 == base1 + size1)
  66                 return 1;
  67         else if (base1 == base2 + size2)
  68                 return -1;
  69
  70         return 0;
  71 }
  72
  73 static long __init lmb_regions_adjacent(struct lmb_region *rgn,
  74                 unsigned long r1, unsigned long r2)
  75 {
  76         unsigned long base1 = rgn->region[r1].base;
  77         unsigned long size1 = rgn->region[r1].size;
  78         unsigned long base2 = rgn->region[r2].base;
  79         unsigned long size2 = rgn->region[r2].size;
  80
  81         return lmb_addrs_adjacent(base1, size1, base2, size2);
  82 }
  83
  84 static void __init lmb_remove_region(struct lmb_region *rgn, unsigned long r)
  85 {
  86         unsigned long i;
  87
  88         for (i = r; i < rgn->cnt - 1; i++) {
  89                 rgn->region[i].base = rgn->region[i + 1].base;
  90                 rgn->region[i].size = rgn->region[i + 1].size;
  91         }
  92         rgn->cnt--;
  93 }
  94
  95 /* Assumption: base addr of region 1 < base addr of region 2 */
  96 static void __init lmb_coalesce_regions(struct lmb_region *rgn,
  97                 unsigned long r1, unsigned long r2)
  98 {
  99         rgn->region[r1].size += rgn->region[r2].size;
 100         lmb_remove_region(rgn, r2);
 101 }
 102
 103 /* This routine called with relocation disabled. */
 104 void __init lmb_init(void)
 105 {
 106         /* Create a dummy zero size LMB which will get coalesced away later.
 107          * This simplifies the lmb_add() code below...
 108          */
 109         lmb.memory.region[0].base = 0;
 110         lmb.memory.region[0].size = 0;
 111         lmb.memory.cnt = 1;
 112
 113         /* Ditto. */
 114         lmb.reserved.region[0].base = 0;
 115         lmb.reserved.region[0].size = 0;
 116         lmb.reserved.cnt = 1;
 117 }
 118
 119 /* This routine may be called with relocation disabled. */
 120 void __init lmb_analyze(void)
 121 {
 122         int i;
 123
 124         lmb.memory.size = 0;
 125
 126         for (i = 0; i < lmb.memory.cnt; i++)
 127                 lmb.memory.size += lmb.memory.region[i].size;
 128 }
 129
 130 /* This routine called with relocation disabled. */
 131 static long __init lmb_add_region(struct lmb_region *rgn, unsigned long base,
 132                                   unsigned long 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                 unsigned long rgnbase = rgn->region[i].base;
 146                 unsigned long 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(unsigned long base, unsigned long 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(unsigned long base, unsigned long 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, unsigned long base,
 215                                 unsigned long size)
 216 {
 217         unsigned long i;
 218
 219         for (i=0; i < rgn->cnt; i++) {
 220                 unsigned long rgnbase = rgn->region[i].base;
 221                 unsigned long 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 unsigned long __init lmb_alloc(unsigned long size, unsigned long align)
 231 {
 232         return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
 233 }
 234
 235 unsigned long __init lmb_alloc_base(unsigned long size, unsigned long align,
 236                                     unsigned long max_addr)
 237 {
 238         unsigned long alloc;
 239
 240         alloc = __lmb_alloc_base(size, align, max_addr);
 241
 242         if (alloc == 0)
 243                 panic("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
 244                                 size, max_addr);
 245
 246         return alloc;
 247 }
 248
 249 static unsigned long lmb_align_down(unsigned long addr, unsigned long size)
 250 {
 251         return addr & ~(size - 1);
 252 }
 253
 254 static unsigned long lmb_align_up(unsigned long addr, unsigned long size)
 255 {
 256         return (addr + (size - 1)) & ~(size - 1);
 257 }
 258
 259 unsigned long __init __lmb_alloc_base(unsigned long size, unsigned long align,
 260                                     unsigned long max_addr)
 261 {
 262         long i, j;
 263         unsigned long base = 0;
 264
 265         BUG_ON(0 == size);
 266
 267         /* On some platforms, make sure we allocate lowmem */
 268         if (max_addr == LMB_ALLOC_ANYWHERE)
 269                 max_addr = LMB_REAL_LIMIT;
 270
 271         for (i = lmb.memory.cnt-1; i >= 0; i--) {
 272                 unsigned long lmbbase = lmb.memory.region[i].base;
 273                 unsigned long lmbsize = lmb.memory.region[i].size;
 274
 275                 if (max_addr == LMB_ALLOC_ANYWHERE)
 276                         base = lmb_align_down(lmbbase + lmbsize - size, align);
 277                 else if (lmbbase < max_addr) {
 278                         base = min(lmbbase + lmbsize, max_addr);
 279                         base = lmb_align_down(base - size, align);
 280                 } else
 281                         continue;
 282
 283                 while ((lmbbase <= base) &&
 284                        ((j = lmb_overlaps_region(&lmb.reserved, base, size)) >= 0) )
 285                         base = lmb_align_down(lmb.reserved.region[j].base - size,
 286                                               align);
 287
 288                 if ((base != 0) && (lmbbase <= base))
 289                         break;
 290         }
 291
 292         if (i < 0)
 293                 return 0;
 294
 295         if (lmb_add_region(&lmb.reserved, base, lmb_align_up(size, align)) < 0)
 296                 return 0;
 297
 298         return base;
 299 }
 300
 301 /* You must call lmb_analyze() before this. */
 302 unsigned long __init lmb_phys_mem_size(void)
 303 {
 304         return lmb.memory.size;
 305 }
 306
 307 unsigned long __init lmb_end_of_DRAM(void)
 308 {
 309         int idx = lmb.memory.cnt - 1;
 310
 311         return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
 312 }
 313
 314 /* You must call lmb_analyze() after this. */
 315 void __init lmb_enforce_memory_limit(unsigned long memory_limit)
 316 {
 317         unsigned long i, limit;
 318         struct lmb_property *p;
 319
 320         if (! memory_limit)
 321                 return;
 322
 323         /* Truncate the lmb regions to satisfy the memory limit. */
 324         limit = memory_limit;
 325         for (i = 0; i < lmb.memory.cnt; i++) {
 326                 if (limit > lmb.memory.region[i].size) {
 327                         limit -= lmb.memory.region[i].size;
 328                         continue;
 329                 }
 330
 331                 lmb.memory.region[i].size = limit;
 332                 lmb.memory.cnt = i + 1;
 333                 break;
 334         }
 335
 336         if (lmb.memory.region[0].size < lmb.rmo_size)
 337                 lmb.rmo_size = lmb.memory.region[0].size;
 338
 339         /* And truncate any reserves above the limit also. */
 340         for (i = 0; i < lmb.reserved.cnt; i++) {
 341                 p = &lmb.reserved.region[i];
 342
 343                 if (p->base > memory_limit)
 344                         p->size = 0;
 345                 else if ((p->base + p->size) > memory_limit)
 346                         p->size = memory_limit - p->base;
 347
 348                 if (p->size == 0) {
 349                         lmb_remove_region(&lmb.reserved, i);
 350                         i--;
 351                 }
 352         }
 353 }
 354
 355 int __init lmb_is_reserved(unsigned long addr)
 356 {
 357         int i;
 358
 359         for (i = 0; i < lmb.reserved.cnt; i++) {
 360                 unsigned long upper = lmb.reserved.region[i].base +
 361                                       lmb.reserved.region[i].size - 1;
 362                 if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
 363                         return 1;
 364         }
 365         return 0;
 366 }