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