lib_generic/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 <common.h>
  14 #include <lmb.h>
  15
  16 #define LMB_ALLOC_ANYWHERE      0
  17
  18 void lmb_dump_all(struct lmb *lmb)
  19 {
  20 #ifdef DEBUG
  21         unsigned long i;
  22
  23         debug("lmb_dump_all:\n");
  24         debug("    memory.cnt              = 0x%lx\n", lmb->memory.cnt);
  25         debug("    memory.size             = 0x%08x\n", lmb->memory.size);
  26         for (i=0; i < lmb->memory.cnt ;i++) {
  27                 debug("    memory.reg[0x%x].base   = 0x%08x\n", i,
  28                         lmb->memory.region[i].base);
  29                 debug("            .size   = 0x%08x\n",
  30                         lmb->memory.region[i].size);
  31         }
  32
  33         debug("\n    reserved.cnt          = 0x%lx\n", lmb->reserved.cnt);
  34         debug("    reserved.size           = 0x%08x\n", lmb->reserved.size);
  35         for (i=0; i < lmb->reserved.cnt ;i++) {
  36                 debug("    reserved.reg[0x%x].base = 0x%08x\n", i,
  37                         lmb->reserved.region[i].base);
  38                 debug("              .size = 0x%08x\n",
  39                         lmb->reserved.region[i].size);
  40         }
  41 #endif /* DEBUG */
  42 }
  43
  44 static unsigned long lmb_addrs_overlap(ulong base1,
  45                 ulong size1, ulong base2, ulong size2)
  46 {
  47         return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
  48 }
  49
  50 static long lmb_addrs_adjacent(ulong base1, ulong size1,
  51                 ulong base2, ulong size2)
  52 {
  53         if (base2 == base1 + size1)
  54                 return 1;
  55         else if (base1 == base2 + size2)
  56                 return -1;
  57
  58         return 0;
  59 }
  60
  61 static long lmb_regions_adjacent(struct lmb_region *rgn,
  62                 unsigned long r1, unsigned long r2)
  63 {
  64         ulong base1 = rgn->region[r1].base;
  65         ulong size1 = rgn->region[r1].size;
  66         ulong base2 = rgn->region[r2].base;
  67         ulong size2 = rgn->region[r2].size;
  68
  69         return lmb_addrs_adjacent(base1, size1, base2, size2);
  70 }
  71
  72 static void lmb_remove_region(struct lmb_region *rgn, unsigned long r)
  73 {
  74         unsigned long i;
  75
  76         for (i = r; i < rgn->cnt - 1; i++) {
  77                 rgn->region[i].base = rgn->region[i + 1].base;
  78                 rgn->region[i].size = rgn->region[i + 1].size;
  79         }
  80         rgn->cnt--;
  81 }
  82
  83 /* Assumption: base addr of region 1 < base addr of region 2 */
  84 static void lmb_coalesce_regions(struct lmb_region *rgn,
  85                 unsigned long r1, unsigned long r2)
  86 {
  87         rgn->region[r1].size += rgn->region[r2].size;
  88         lmb_remove_region(rgn, r2);
  89 }
  90
  91 void lmb_init(struct lmb *lmb)
  92 {
  93         /* Create a dummy zero size LMB which will get coalesced away later.
  94          * This simplifies the lmb_add() code below...
  95          */
  96         lmb->memory.region[0].base = 0;
  97         lmb->memory.region[0].size = 0;
  98         lmb->memory.cnt = 1;
  99         lmb->memory.size = 0;
 100
 101         /* Ditto. */
 102         lmb->reserved.region[0].base = 0;
 103         lmb->reserved.region[0].size = 0;
 104         lmb->reserved.cnt = 1;
 105         lmb->reserved.size = 0;
 106 }
 107
 108 /* This routine called with relocation disabled. */
 109 static long lmb_add_region(struct lmb_region *rgn, ulong base, ulong size)
 110 {
 111         unsigned long coalesced = 0;
 112         long adjacent, i;
 113
 114         if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
 115                 rgn->region[0].base = base;
 116                 rgn->region[0].size = size;
 117                 return 0;
 118         }
 119
 120         /* First try and coalesce this LMB with another. */
 121         for (i=0; i < rgn->cnt; i++) {
 122                 ulong rgnbase = rgn->region[i].base;
 123                 ulong rgnsize = rgn->region[i].size;
 124
 125                 if ((rgnbase == base) && (rgnsize == size))
 126                         /* Already have this region, so we're done */
 127                         return 0;
 128
 129                 adjacent = lmb_addrs_adjacent(base,size,rgnbase,rgnsize);
 130                 if ( adjacent > 0 ) {
 131                         rgn->region[i].base -= size;
 132                         rgn->region[i].size += size;
 133                         coalesced++;
 134                         break;
 135                 }
 136                 else if ( adjacent < 0 ) {
 137                         rgn->region[i].size += size;
 138                         coalesced++;
 139                         break;
 140                 }
 141         }
 142
 143         if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
 144                 lmb_coalesce_regions(rgn, i, i+1);
 145                 coalesced++;
 146         }
 147
 148         if (coalesced)
 149                 return coalesced;
 150         if (rgn->cnt >= MAX_LMB_REGIONS)
 151                 return -1;
 152
 153         /* Couldn't coalesce the LMB, so add it to the sorted table. */
 154         for (i = rgn->cnt-1; i >= 0; i--) {
 155                 if (base < rgn->region[i].base) {
 156                         rgn->region[i+1].base = rgn->region[i].base;
 157                         rgn->region[i+1].size = rgn->region[i].size;
 158                 } else {
 159                         rgn->region[i+1].base = base;
 160                         rgn->region[i+1].size = size;
 161                         break;
 162                 }
 163         }
 164
 165         if (base < rgn->region[0].base) {
 166                 rgn->region[0].base = base;
 167                 rgn->region[0].size = size;
 168         }
 169
 170         rgn->cnt++;
 171
 172         return 0;
 173 }
 174
 175 /* This routine may be called with relocation disabled. */
 176 long lmb_add(struct lmb *lmb, ulong base, ulong size)
 177 {
 178         struct lmb_region *_rgn = &(lmb->memory);
 179
 180         return lmb_add_region(_rgn, base, size);
 181 }
 182
 183 long lmb_reserve(struct lmb *lmb, ulong base, ulong size)
 184 {
 185         struct lmb_region *_rgn = &(lmb->reserved);
 186
 187         return lmb_add_region(_rgn, base, size);
 188 }
 189
 190 long lmb_overlaps_region(struct lmb_region *rgn, ulong base,
 191                                 ulong size)
 192 {
 193         unsigned long i;
 194
 195         for (i=0; i < rgn->cnt; i++) {
 196                 ulong rgnbase = rgn->region[i].base;
 197                 ulong rgnsize = rgn->region[i].size;
 198                 if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
 199                         break;
 200                 }
 201         }
 202
 203         return (i < rgn->cnt) ? i : -1;
 204 }
 205
 206 ulong lmb_alloc(struct lmb *lmb, ulong size, ulong align)
 207 {
 208         return lmb_alloc_base(lmb, size, align, LMB_ALLOC_ANYWHERE);
 209 }
 210
 211 ulong lmb_alloc_base(struct lmb *lmb, ulong size, ulong align, ulong max_addr)
 212 {
 213         ulong alloc;
 214
 215         alloc = __lmb_alloc_base(lmb, size, align, max_addr);
 216
 217         if (alloc == 0)
 218                 printf("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
 219                       size, max_addr);
 220
 221         return alloc;
 222 }
 223
 224 static ulong lmb_align_down(ulong addr, ulong size)
 225 {
 226         return addr & ~(size - 1);
 227 }
 228
 229 static ulong lmb_align_up(ulong addr, ulong size)
 230 {
 231         return (addr + (size - 1)) & ~(size - 1);
 232 }
 233
 234 ulong __lmb_alloc_base(struct lmb *lmb, ulong size, ulong align, ulong max_addr)
 235 {
 236         long i, j;
 237         ulong base = 0;
 238
 239         for (i = lmb->memory.cnt-1; i >= 0; i--) {
 240                 ulong lmbbase = lmb->memory.region[i].base;
 241                 ulong lmbsize = lmb->memory.region[i].size;
 242
 243                 if (max_addr == LMB_ALLOC_ANYWHERE)
 244                         base = lmb_align_down(lmbbase + lmbsize - size, align);
 245                 else if (lmbbase < max_addr) {
 246                         base = min(lmbbase + lmbsize, max_addr);
 247                         base = lmb_align_down(base - size, align);
 248                 } else
 249                         continue;
 250
 251                 while ((lmbbase <= base) &&
 252                        ((j = lmb_overlaps_region(&(lmb->reserved), base, size)) >= 0) )
 253                         base = lmb_align_down(lmb->reserved.region[j].base - size,
 254                                               align);
 255
 256                 if ((base != 0) && (lmbbase <= base))
 257                         break;
 258         }
 259
 260         if (i < 0)
 261                 return 0;
 262
 263         if (lmb_add_region(&(lmb->reserved), base, lmb_align_up(size, align)) < 0)
 264                 return 0;
 265
 266         return base;
 267 }
 268
 269 int lmb_is_reserved(struct lmb *lmb, ulong addr)
 270 {
 271         int i;
 272
 273         for (i = 0; i < lmb->reserved.cnt; i++) {
 274                 ulong upper = lmb->reserved.region[i].base +
 275                         lmb->reserved.region[i].size - 1;
 276                 if ((addr >= lmb->reserved.region[i].base) && (addr <= upper))
 277                         return 1;
 278         }
 279         return 0;
 280 }