arch/ppc64/kernel/lmb.c

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