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 struct lmb lmb;
  35
  36 void lmb_dump_all(void)
  37 {
  38 #ifdef DEBUG
  39         unsigned long i;
  40
  41         DBG("lmb_dump_all:\n");
  42         DBG("    memory.cnt               = 0x%lx\n", lmb.memory.cnt);
  43         DBG("    memory.size              = 0x%lx\n", lmb.memory.size);
  44         for (i=0; i < lmb.memory.cnt ;i++) {
  45                 DBG("    memory.region[0x%x].base       = 0x%lx\n",
  46                             i, lmb.memory.region[i].base);
  47                 DBG("                 .size     = 0x%lx\n",
  48                             lmb.memory.region[i].size);
  49         }
  50
  51         DBG("\n    reserved.cnt   = 0x%lx\n", lmb.reserved.cnt);
  52         DBG("    reserved.size    = 0x%lx\n", lmb.reserved.size);
  53         for (i=0; i < lmb.reserved.cnt ;i++) {
  54                 DBG("    reserved.region[0x%x].base       = 0x%lx\n",
  55                             i, lmb.reserved.region[i].base);
  56                 DBG("                 .size     = 0x%lx\n",
  57                             lmb.reserved.region[i].size);
  58         }
  59 #endif /* DEBUG */
  60 }
  61
  62 static unsigned long __init lmb_addrs_overlap(unsigned long base1,
  63                 unsigned long size1, unsigned long base2, unsigned long size2)
  64 {
  65         return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
  66 }
  67
  68 static long __init lmb_addrs_adjacent(unsigned long base1, unsigned long size1,
  69                 unsigned long base2, unsigned long size2)
  70 {
  71         if (base2 == base1 + size1)
  72                 return 1;
  73         else if (base1 == base2 + size2)
  74                 return -1;
  75
  76         return 0;
  77 }
  78
  79 static long __init lmb_regions_adjacent(struct lmb_region *rgn,
  80                 unsigned long r1, unsigned long r2)
  81 {
  82         unsigned long base1 = rgn->region[r1].base;
  83         unsigned long size1 = rgn->region[r1].size;
  84         unsigned long base2 = rgn->region[r2].base;
  85         unsigned long size2 = rgn->region[r2].size;
  86
  87         return lmb_addrs_adjacent(base1, size1, base2, size2);
  88 }
  89
  90 /* Assumption: base addr of region 1 < base addr of region 2 */
  91 static void __init lmb_coalesce_regions(struct lmb_region *rgn,
  92                 unsigned long r1, unsigned long r2)
  93 {
  94         unsigned long i;
  95
  96         rgn->region[r1].size += rgn->region[r2].size;
  97         for (i=r2; i < rgn->cnt-1; i++) {
  98                 rgn->region[i].base = rgn->region[i+1].base;
  99                 rgn->region[i].size = rgn->region[i+1].size;
 100         }
 101         rgn->cnt--;
 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, unsigned long base,
 133                                   unsigned long size)
 134 {
 135         unsigned long i, coalesced = 0;
 136         long adjacent;
 137
 138         /* First try and coalesce this LMB with another. */
 139         for (i=0; i < rgn->cnt; i++) {
 140                 unsigned long rgnbase = rgn->region[i].base;
 141                 unsigned long rgnsize = rgn->region[i].size;
 142
 143                 adjacent = lmb_addrs_adjacent(base,size,rgnbase,rgnsize);
 144                 if ( adjacent > 0 ) {
 145                         rgn->region[i].base -= size;
 146                         rgn->region[i].size += size;
 147                         coalesced++;
 148                         break;
 149                 }
 150                 else if ( adjacent < 0 ) {
 151                         rgn->region[i].size += size;
 152                         coalesced++;
 153                         break;
 154                 }
 155         }
 156
 157         if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
 158                 lmb_coalesce_regions(rgn, i, i+1);
 159                 coalesced++;
 160         }
 161
 162         if (coalesced)
 163                 return coalesced;
 164         if (rgn->cnt >= MAX_LMB_REGIONS)
 165                 return -1;
 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 may be called with relocation disabled. */
 184 long __init lmb_add(unsigned long base, unsigned long size)
 185 {
 186         struct lmb_region *_rgn = &(lmb.memory);
 187
 188         /* On pSeries LPAR systems, the first LMB is our RMO region. */
 189         if (base == 0)
 190                 lmb.rmo_size = size;
 191
 192         return lmb_add_region(_rgn, base, size);
 193
 194 }
 195
 196 long __init lmb_reserve(unsigned long base, unsigned long size)
 197 {
 198         struct lmb_region *_rgn = &(lmb.reserved);
 199
 200         return lmb_add_region(_rgn, base, size);
 201 }
 202
 203 long __init lmb_overlaps_region(struct lmb_region *rgn, unsigned long base,
 204                                 unsigned long size)
 205 {
 206         unsigned long i;
 207
 208         for (i=0; i < rgn->cnt; i++) {
 209                 unsigned long rgnbase = rgn->region[i].base;
 210                 unsigned long rgnsize = rgn->region[i].size;
 211                 if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
 212                         break;
 213                 }
 214         }
 215
 216         return (i < rgn->cnt) ? i : -1;
 217 }
 218
 219 unsigned long __init lmb_alloc(unsigned long size, unsigned long align)
 220 {
 221         return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
 222 }
 223
 224 unsigned long __init lmb_alloc_base(unsigned long size, unsigned long align,
 225                                     unsigned long max_addr)
 226 {
 227         long i, j;
 228         unsigned long base = 0;
 229
 230 #ifdef CONFIG_PPC32
 231         /* On 32-bit, make sure we allocate lowmem */
 232         if (max_addr == LMB_ALLOC_ANYWHERE)
 233                 max_addr = __max_low_memory;
 234 #endif
 235         for (i = lmb.memory.cnt-1; i >= 0; i--) {
 236                 unsigned long lmbbase = lmb.memory.region[i].base;
 237                 unsigned long lmbsize = lmb.memory.region[i].size;
 238
 239                 if (max_addr == LMB_ALLOC_ANYWHERE)
 240                         base = _ALIGN_DOWN(lmbbase + lmbsize - size, align);
 241                 else if (lmbbase < max_addr) {
 242                         base = min(lmbbase + lmbsize, max_addr);
 243                         base = _ALIGN_DOWN(base - size, align);
 244                 } else
 245                         continue;
 246
 247                 while ((lmbbase <= base) &&
 248                        ((j = lmb_overlaps_region(&lmb.reserved, base, size)) >= 0) )
 249                         base = _ALIGN_DOWN(lmb.reserved.region[j].base - size,
 250                                            align);
 251
 252                 if ((base != 0) && (lmbbase <= base))
 253                         break;
 254         }
 255
 256         if (i < 0)
 257                 return 0;
 258
 259         lmb_add_region(&lmb.reserved, base, size);
 260
 261         return base;
 262 }
 263
 264 /* You must call lmb_analyze() before this. */
 265 unsigned long __init lmb_phys_mem_size(void)
 266 {
 267         return lmb.memory.size;
 268 }
 269
 270 unsigned long __init lmb_end_of_DRAM(void)
 271 {
 272         int idx = lmb.memory.cnt - 1;
 273
 274         return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
 275 }
 276
 277 /*
 278  * Truncate the lmb list to memory_limit if it's set
 279  * You must call lmb_analyze() after this.
 280  */
 281 void __init lmb_enforce_memory_limit(unsigned long memory_limit)
 282 {
 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 }