arch/powerpc/mm/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 <asm/types.h>
  17 #include <asm/page.h>
  18 #include <asm/prom.h>
  19 #include <asm/lmb.h>
  20 #ifdef CONFIG_PPC32
  21 #include "mmu_decl.h"           /* for __max_low_memory */
  22 #endif
  23
  24 #undef DEBUG
  25
  26 #ifdef DEBUG
  27 #include <asm/udbg.h>
  28 #define DBG(fmt...) udbg_printf(fmt)
  29 #else
  30 #define DBG(fmt...)
  31 #endif
  32
  33 #define LMB_ALLOC_ANYWHERE      0
  34
  35 struct lmb lmb;
  36
  37 void lmb_dump_all(void)
  38 {
  39 #ifdef DEBUG
  40         unsigned long i;
  41
  42         DBG("lmb_dump_all:\n");
  43         DBG("    memory.cnt               = 0x%lx\n", lmb.memory.cnt);
  44         DBG("    memory.size              = 0x%lx\n", lmb.memory.size);
  45         for (i=0; i < lmb.memory.cnt ;i++) {
  46                 DBG("    memory.region[0x%x].base       = 0x%lx\n",
  47                             i, lmb.memory.region[i].base);
  48                 DBG("                 .size     = 0x%lx\n",
  49                             lmb.memory.region[i].size);
  50         }
  51
  52         DBG("\n    reserved.cnt   = 0x%lx\n", lmb.reserved.cnt);
  53         DBG("    reserved.size    = 0x%lx\n", lmb.reserved.size);
  54         for (i=0; i < lmb.reserved.cnt ;i++) {
  55                 DBG("    reserved.region[0x%x].base       = 0x%lx\n",
  56                             i, lmb.reserved.region[i].base);
  57                 DBG("                 .size     = 0x%lx\n",
  58                             lmb.reserved.region[i].size);
  59         }
  60 #endif /* DEBUG */
  61 }
  62
  63 static unsigned long __init lmb_addrs_overlap(unsigned long base1,
  64                 unsigned long size1, unsigned long base2, unsigned long size2)
  65 {
  66         return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
  67 }
  68
  69 static long __init lmb_addrs_adjacent(unsigned long base1, unsigned long size1,
  70                 unsigned long base2, unsigned long size2)
  71 {
  72         if (base2 == base1 + size1)
  73                 return 1;
  74         else if (base1 == base2 + size2)
  75                 return -1;
  76
  77         return 0;
  78 }
  79
  80 static long __init lmb_regions_adjacent(struct lmb_region *rgn,
  81                 unsigned long r1, unsigned long r2)
  82 {
  83         unsigned long base1 = rgn->region[r1].base;
  84         unsigned long size1 = rgn->region[r1].size;
  85         unsigned long base2 = rgn->region[r2].base;
  86         unsigned long size2 = rgn->region[r2].size;
  87
  88         return lmb_addrs_adjacent(base1, size1, base2, size2);
  89 }
  90
  91 static void __init lmb_remove_region(struct lmb_region *rgn, unsigned long r)
  92 {
  93         unsigned long i;
  94
  95         for (i = r; i < rgn->cnt - 1; i++) {
  96                 rgn->region[i].base = rgn->region[i + 1].base;
  97                 rgn->region[i].size = rgn->region[i + 1].size;
  98         }
  99         rgn->cnt--;
 100 }
 101
 102 /* Assumption: base addr of region 1 < base addr of region 2 */
 103 static void __init lmb_coalesce_regions(struct lmb_region *rgn,
 104                 unsigned long r1, unsigned long r2)
 105 {
 106         rgn->region[r1].size += rgn->region[r2].size;
 107         lmb_remove_region(rgn, r2);
 108 }
 109
 110 /* This routine called with relocation disabled. */
 111 void __init lmb_init(void)
 112 {
 113         /* Create a dummy zero size LMB which will get coalesced away later.
 114          * This simplifies the lmb_add() code below...
 115          */
 116         lmb.memory.region[0].base = 0;
 117         lmb.memory.region[0].size = 0;
 118         lmb.memory.cnt = 1;
 119
 120         /* Ditto. */
 121         lmb.reserved.region[0].base = 0;
 122         lmb.reserved.region[0].size = 0;
 123         lmb.reserved.cnt = 1;
 124 }
 125
 126 /* This routine may be called with relocation disabled. */
 127 void __init lmb_analyze(void)
 128 {
 129         int i;
 130
 131         lmb.memory.size = 0;
 132
 133         for (i = 0; i < lmb.memory.cnt; i++)
 134                 lmb.memory.size += lmb.memory.region[i].size;
 135 }
 136
 137 /* This routine called with relocation disabled. */
 138 static long __init lmb_add_region(struct lmb_region *rgn, unsigned long base,
 139                                   unsigned long size)
 140 {
 141         unsigned long coalesced = 0;
 142         long adjacent, i;
 143
 144         /* First try and coalesce this LMB with another. */
 145         for (i=0; i < rgn->cnt; i++) {
 146                 unsigned long rgnbase = rgn->region[i].base;
 147                 unsigned long rgnsize = rgn->region[i].size;
 148
 149                 if ((rgnbase == base) && (rgnsize == size))
 150                         /* Already have this region, so we're done */
 151                         return 0;
 152
 153                 adjacent = lmb_addrs_adjacent(base,size,rgnbase,rgnsize);
 154                 if ( adjacent > 0 ) {
 155                         rgn->region[i].base -= size;
 156                         rgn->region[i].size += size;
 157                         coalesced++;
 158                         break;
 159                 }
 160                 else if ( adjacent < 0 ) {
 161                         rgn->region[i].size += size;
 162                         coalesced++;
 163                         break;
 164                 }
 165         }
 166
 167         if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
 168                 lmb_coalesce_regions(rgn, i, i+1);
 169                 coalesced++;
 170         }
 171
 172         if (coalesced)
 173                 return coalesced;
 174         if (rgn->cnt >= MAX_LMB_REGIONS)
 175                 return -1;
 176
 177         /* Couldn't coalesce the LMB, so add it to the sorted table. */
 178         for (i = rgn->cnt-1; i >= 0; i--) {
 179                 if (base < rgn->region[i].base) {
 180                         rgn->region[i+1].base = rgn->region[i].base;
 181                         rgn->region[i+1].size = rgn->region[i].size;
 182                 } else {
 183                         rgn->region[i+1].base = base;
 184                         rgn->region[i+1].size = size;
 185                         break;
 186                 }
 187         }
 188         rgn->cnt++;
 189
 190         return 0;
 191 }
 192
 193 /* This routine may be called with relocation disabled. */
 194 long __init lmb_add(unsigned long base, unsigned long size)
 195 {
 196         struct lmb_region *_rgn = &(lmb.memory);
 197
 198         /* On pSeries LPAR systems, the first LMB is our RMO region. */
 199         if (base == 0)
 200                 lmb.rmo_size = size;
 201
 202         return lmb_add_region(_rgn, base, size);
 203
 204 }
 205
 206 long __init lmb_reserve(unsigned long base, unsigned long size)
 207 {
 208         struct lmb_region *_rgn = &(lmb.reserved);
 209
 210         BUG_ON(0 == size);
 211
 212         return lmb_add_region(_rgn, base, size);
 213 }
 214
 215 long __init lmb_overlaps_region(struct lmb_region *rgn, unsigned long base,
 216                                 unsigned long size)
 217 {
 218         unsigned long i;
 219
 220         for (i=0; i < rgn->cnt; i++) {
 221                 unsigned long rgnbase = rgn->region[i].base;
 222                 unsigned long rgnsize = rgn->region[i].size;
 223                 if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
 224                         break;
 225                 }
 226         }
 227
 228         return (i < rgn->cnt) ? i : -1;
 229 }
 230
 231 unsigned long __init lmb_alloc(unsigned long size, unsigned long align)
 232 {
 233         return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
 234 }
 235
 236 unsigned long __init lmb_alloc_base(unsigned long size, unsigned long align,
 237                                     unsigned long max_addr)
 238 {
 239         unsigned long alloc;
 240
 241         alloc = __lmb_alloc_base(size, align, max_addr);
 242
 243         if (alloc == 0)
 244                 panic("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
 245                                 size, max_addr);
 246
 247         return alloc;
 248 }
 249
 250 unsigned long __init __lmb_alloc_base(unsigned long size, unsigned long align,
 251                                     unsigned long max_addr)
 252 {
 253         long i, j;
 254         unsigned long base = 0;
 255
 256         BUG_ON(0 == size);
 257
 258 #ifdef CONFIG_PPC32
 259         /* On 32-bit, make sure we allocate lowmem */
 260         if (max_addr == LMB_ALLOC_ANYWHERE)
 261                 max_addr = __max_low_memory;
 262 #endif
 263         for (i = lmb.memory.cnt-1; i >= 0; i--) {
 264                 unsigned long lmbbase = lmb.memory.region[i].base;
 265                 unsigned long lmbsize = lmb.memory.region[i].size;
 266
 267                 if (max_addr == LMB_ALLOC_ANYWHERE)
 268                         base = _ALIGN_DOWN(lmbbase + lmbsize - size, align);
 269                 else if (lmbbase < max_addr) {
 270                         base = min(lmbbase + lmbsize, max_addr);
 271                         base = _ALIGN_DOWN(base - size, align);
 272                 } else
 273                         continue;
 274
 275                 while ((lmbbase <= base) &&
 276                        ((j = lmb_overlaps_region(&lmb.reserved, base, size)) >= 0) )
 277                         base = _ALIGN_DOWN(lmb.reserved.region[j].base - size,
 278                                            align);
 279
 280                 if ((base != 0) && (lmbbase <= base))
 281                         break;
 282         }
 283
 284         if (i < 0)
 285                 return 0;
 286
 287         lmb_add_region(&lmb.reserved, base, size);
 288
 289         return base;
 290 }
 291
 292 /* You must call lmb_analyze() before this. */
 293 unsigned long __init lmb_phys_mem_size(void)
 294 {
 295         return lmb.memory.size;
 296 }
 297
 298 unsigned long __init lmb_end_of_DRAM(void)
 299 {
 300         int idx = lmb.memory.cnt - 1;
 301
 302         return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
 303 }
 304
 305 /* You must call lmb_analyze() after this. */
 306 void __init lmb_enforce_memory_limit(unsigned long memory_limit)
 307 {
 308         unsigned long i, limit;
 309         struct lmb_property *p;
 310
 311         if (! memory_limit)
 312                 return;
 313
 314         /* Truncate the lmb regions to satisfy the memory limit. */
 315         limit = memory_limit;
 316         for (i = 0; i < lmb.memory.cnt; i++) {
 317                 if (limit > lmb.memory.region[i].size) {
 318                         limit -= lmb.memory.region[i].size;
 319                         continue;
 320                 }
 321
 322                 lmb.memory.region[i].size = limit;
 323                 lmb.memory.cnt = i + 1;
 324                 break;
 325         }
 326
 327         if (lmb.memory.region[0].size < lmb.rmo_size)
 328                 lmb.rmo_size = lmb.memory.region[0].size;
 329
 330         /* And truncate any reserves above the limit also. */
 331         for (i = 0; i < lmb.reserved.cnt; i++) {
 332                 p = &lmb.reserved.region[i];
 333
 334                 if (p->base > memory_limit)
 335                         p->size = 0;
 336                 else if ((p->base + p->size) > memory_limit)
 337                         p->size = memory_limit - p->base;
 338
 339                 if (p->size == 0) {
 340                         lmb_remove_region(&lmb.reserved, i);
 341                         i--;
 342                 }
 343         }
 344 }