kernel/early_res.c

   1 /*
   2  * early_res, could be used to replace bootmem
   3  */
   4 #include <linux/kernel.h>
   5 #include <linux/types.h>
   6 #include <linux/init.h>
   7 #include <linux/bootmem.h>
   8 #include <linux/mm.h>
   9 #include <linux/early_res.h>
  10
  11 /*
  12  * Early reserved memory areas.
  13  */
  14 /*
  15  * need to make sure this one is bigger enough before
  16  * find_fw_memmap_area could be used
  17  */
  18 #define MAX_EARLY_RES_X 32
  19
  20 struct early_res {
  21         u64 start, end;
  22         char name[15];
  23         char overlap_ok;
  24 };
  25 static struct early_res early_res_x[MAX_EARLY_RES_X] __initdata;
  26
  27 static int max_early_res __initdata = MAX_EARLY_RES_X;
  28 static struct early_res *early_res __initdata = &early_res_x[0];
  29 static int early_res_count __initdata;
  30
  31 static int __init find_overlapped_early(u64 start, u64 end)
  32 {
  33         int i;
  34         struct early_res *r;
  35
  36         for (i = 0; i < max_early_res && early_res[i].end; i++) {
  37                 r = &early_res[i];
  38                 if (end > r->start && start < r->end)
  39                         break;
  40         }
  41
  42         return i;
  43 }
  44
  45 /*
  46  * Drop the i-th range from the early reservation map,
  47  * by copying any higher ranges down one over it, and
  48  * clearing what had been the last slot.
  49  */
  50 static void __init drop_range(int i)
  51 {
  52         int j;
  53
  54         for (j = i + 1; j < max_early_res && early_res[j].end; j++)
  55                 ;
  56
  57         memmove(&early_res[i], &early_res[i + 1],
  58                (j - 1 - i) * sizeof(struct early_res));
  59
  60         early_res[j - 1].end = 0;
  61         early_res_count--;
  62 }
  63
  64 static void __init drop_range_partial(int i, u64 start, u64 end)
  65 {
  66         u64 common_start, common_end;
  67         u64 old_start, old_end;
  68
  69         old_start = early_res[i].start;
  70         old_end = early_res[i].end;
  71         common_start = max(old_start, start);
  72         common_end = min(old_end, end);
  73
  74         /* no overlap ? */
  75         if (common_start >= common_end)
  76                 return;
  77
  78         if (old_start < common_start) {
  79                 /* make head segment */
  80                 early_res[i].end = common_start;
  81                 if (old_end > common_end) {
  82                         char name[15];
  83
  84                         /*
  85                          * Save a local copy of the name, since the
  86                          * early_res array could get resized inside
  87                          * reserve_early_without_check() ->
  88                          * __check_and_double_early_res(), which would
  89                          * make the current name pointer invalid.
  90                          */
  91                         strncpy(name, early_res[i].name,
  92                                          sizeof(early_res[i].name) - 1);
  93                         /* add another for left over on tail */
  94                         reserve_early_without_check(common_end, old_end, name);
  95                 }
  96                 return;
  97         } else {
  98                 if (old_end > common_end) {
  99                         /* reuse the entry for tail left */
 100                         early_res[i].start = common_end;
 101                         return;
 102                 }
 103                 /* all covered */
 104                 drop_range(i);
 105         }
 106 }
 107
 108 /*
 109  * Split any existing ranges that:
 110  *  1) are marked 'overlap_ok', and
 111  *  2) overlap with the stated range [start, end)
 112  * into whatever portion (if any) of the existing range is entirely
 113  * below or entirely above the stated range.  Drop the portion
 114  * of the existing range that overlaps with the stated range,
 115  * which will allow the caller of this routine to then add that
 116  * stated range without conflicting with any existing range.
 117  */
 118 static void __init drop_overlaps_that_are_ok(u64 start, u64 end)
 119 {
 120         int i;
 121         struct early_res *r;
 122         u64 lower_start, lower_end;
 123         u64 upper_start, upper_end;
 124         char name[15];
 125
 126         for (i = 0; i < max_early_res && early_res[i].end; i++) {
 127                 r = &early_res[i];
 128
 129                 /* Continue past non-overlapping ranges */
 130                 if (end <= r->start || start >= r->end)
 131                         continue;
 132
 133                 /*
 134                  * Leave non-ok overlaps as is; let caller
 135                  * panic "Overlapping early reservations"
 136                  * when it hits this overlap.
 137                  */
 138                 if (!r->overlap_ok)
 139                         return;
 140
 141                 /*
 142                  * We have an ok overlap.  We will drop it from the early
 143                  * reservation map, and add back in any non-overlapping
 144                  * portions (lower or upper) as separate, overlap_ok,
 145                  * non-overlapping ranges.
 146                  */
 147
 148                 /* 1. Note any non-overlapping (lower or upper) ranges. */
 149                 strncpy(name, r->name, sizeof(name) - 1);
 150
 151                 lower_start = lower_end = 0;
 152                 upper_start = upper_end = 0;
 153                 if (r->start < start) {
 154                         lower_start = r->start;
 155                         lower_end = start;
 156                 }
 157                 if (r->end > end) {
 158                         upper_start = end;
 159                         upper_end = r->end;
 160                 }
 161
 162                 /* 2. Drop the original ok overlapping range */
 163                 drop_range(i);
 164
 165                 i--;            /* resume for-loop on copied down entry */
 166
 167                 /* 3. Add back in any non-overlapping ranges. */
 168                 if (lower_end)
 169                         reserve_early_overlap_ok(lower_start, lower_end, name);
 170                 if (upper_end)
 171                         reserve_early_overlap_ok(upper_start, upper_end, name);
 172         }
 173 }
 174
 175 static void __init __reserve_early(u64 start, u64 end, char *name,
 176                                                 int overlap_ok)
 177 {
 178         int i;
 179         struct early_res *r;
 180
 181         i = find_overlapped_early(start, end);
 182         if (i >= max_early_res)
 183                 panic("Too many early reservations");
 184         r = &early_res[i];
 185         if (r->end)
 186                 panic("Overlapping early reservations "
 187                       "%llx-%llx %s to %llx-%llx %s\n",
 188                       start, end - 1, name ? name : "", r->start,
 189                       r->end - 1, r->name);
 190         r->start = start;
 191         r->end = end;
 192         r->overlap_ok = overlap_ok;
 193         if (name)
 194                 strncpy(r->name, name, sizeof(r->name) - 1);
 195         early_res_count++;
 196 }
 197
 198 /*
 199  * A few early reservtations come here.
 200  *
 201  * The 'overlap_ok' in the name of this routine does -not- mean it
 202  * is ok for these reservations to overlap an earlier reservation.
 203  * Rather it means that it is ok for subsequent reservations to
 204  * overlap this one.
 205  *
 206  * Use this entry point to reserve early ranges when you are doing
 207  * so out of "Paranoia", reserving perhaps more memory than you need,
 208  * just in case, and don't mind a subsequent overlapping reservation
 209  * that is known to be needed.
 210  *
 211  * The drop_overlaps_that_are_ok() call here isn't really needed.
 212  * It would be needed if we had two colliding 'overlap_ok'
 213  * reservations, so that the second such would not panic on the
 214  * overlap with the first.  We don't have any such as of this
 215  * writing, but might as well tolerate such if it happens in
 216  * the future.
 217  */
 218 void __init reserve_early_overlap_ok(u64 start, u64 end, char *name)
 219 {
 220         drop_overlaps_that_are_ok(start, end);
 221         __reserve_early(start, end, name, 1);
 222 }
 223
 224 static void __init __check_and_double_early_res(u64 ex_start, u64 ex_end)
 225 {
 226         u64 start, end, size, mem;
 227         struct early_res *new;
 228
 229         /* do we have enough slots left ? */
 230         if ((max_early_res - early_res_count) > max(max_early_res/8, 2))
 231                 return;
 232
 233         /* double it */
 234         mem = -1ULL;
 235         size = sizeof(struct early_res) * max_early_res * 2;
 236         if (early_res == early_res_x)
 237                 start = 0;
 238         else
 239                 start = early_res[0].end;
 240         end = ex_start;
 241         if (start + size < end)
 242                 mem = find_fw_memmap_area(start, end, size,
 243                                          sizeof(struct early_res));
 244         if (mem == -1ULL) {
 245                 start = ex_end;
 246                 end = get_max_mapped();
 247                 if (start + size < end)
 248                         mem = find_fw_memmap_area(start, end, size,
 249                                                  sizeof(struct early_res));
 250         }
 251         if (mem == -1ULL)
 252                 panic("can not find more space for early_res array");
 253
 254         new = __va(mem);
 255         /* save the first one for own */
 256         new[0].start = mem;
 257         new[0].end = mem + size;
 258         new[0].overlap_ok = 0;
 259         /* copy old to new */
 260         if (early_res == early_res_x) {
 261                 memcpy(&new[1], &early_res[0],
 262                          sizeof(struct early_res) * max_early_res);
 263                 memset(&new[max_early_res+1], 0,
 264                          sizeof(struct early_res) * (max_early_res - 1));
 265                 early_res_count++;
 266         } else {
 267                 memcpy(&new[1], &early_res[1],
 268                          sizeof(struct early_res) * (max_early_res - 1));
 269                 memset(&new[max_early_res], 0,
 270                          sizeof(struct early_res) * max_early_res);
 271         }
 272         memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);
 273         early_res = new;
 274         max_early_res *= 2;
 275         printk(KERN_DEBUG "early_res array is doubled to %d at [%llx - %llx]\n",
 276                 max_early_res, mem, mem + size - 1);
 277 }
 278
 279 /*
 280  * Most early reservations come here.
 281  *
 282  * We first have drop_overlaps_that_are_ok() drop any pre-existing
 283  * 'overlap_ok' ranges, so that we can then reserve this memory
 284  * range without risk of panic'ing on an overlapping overlap_ok
 285  * early reservation.
 286  */
 287 void __init reserve_early(u64 start, u64 end, char *name)
 288 {
 289         if (start >= end)
 290                 return;
 291
 292         __check_and_double_early_res(start, end);
 293
 294         drop_overlaps_that_are_ok(start, end);
 295         __reserve_early(start, end, name, 0);
 296 }
 297
 298 void __init reserve_early_without_check(u64 start, u64 end, char *name)
 299 {
 300         struct early_res *r;
 301
 302         if (start >= end)
 303                 return;
 304
 305         __check_and_double_early_res(start, end);
 306
 307         r = &early_res[early_res_count];
 308
 309         r->start = start;
 310         r->end = end;
 311         r->overlap_ok = 0;
 312         if (name)
 313                 strncpy(r->name, name, sizeof(r->name) - 1);
 314         early_res_count++;
 315 }
 316
 317 void __init free_early(u64 start, u64 end)
 318 {
 319         struct early_res *r;
 320         int i;
 321
 322         i = find_overlapped_early(start, end);
 323         r = &early_res[i];
 324         if (i >= max_early_res || r->end != end || r->start != start)
 325                 panic("free_early on not reserved area: %llx-%llx!",
 326                          start, end - 1);
 327
 328         drop_range(i);
 329 }
 330
 331 void __init free_early_partial(u64 start, u64 end)
 332 {
 333         struct early_res *r;
 334         int i;
 335
 336 try_next:
 337         i = find_overlapped_early(start, end);
 338         if (i >= max_early_res)
 339                 return;
 340
 341         r = &early_res[i];
 342         /* hole ? */
 343         if (r->end >= end && r->start <= start) {
 344                 drop_range_partial(i, start, end);
 345                 return;
 346         }
 347
 348         drop_range_partial(i, start, end);
 349         goto try_next;
 350 }
 351
 352 #ifdef CONFIG_NO_BOOTMEM
 353 static void __init subtract_early_res(struct range *range, int az)
 354 {
 355         int i, count;
 356         u64 final_start, final_end;
 357         int idx = 0;
 358
 359         count  = 0;
 360         for (i = 0; i < max_early_res && early_res[i].end; i++)
 361                 count++;
 362
 363         /* need to skip first one ?*/
 364         if (early_res != early_res_x)
 365                 idx = 1;
 366
 367 #define DEBUG_PRINT_EARLY_RES 1
 368
 369 #if DEBUG_PRINT_EARLY_RES
 370         printk(KERN_INFO "Subtract (%d early reservations)\n", count);
 371 #endif
 372         for (i = idx; i < count; i++) {
 373                 struct early_res *r = &early_res[i];
 374 #if DEBUG_PRINT_EARLY_RES
 375                 printk(KERN_INFO "  #%d [%010llx - %010llx] %15s\n", i,
 376                         r->start, r->end, r->name);
 377 #endif
 378                 final_start = PFN_DOWN(r->start);
 379                 final_end = PFN_UP(r->end);
 380                 if (final_start >= final_end)
 381                         continue;
 382                 subtract_range(range, az, final_start, final_end);
 383         }
 384
 385 }
 386
 387 int __init get_free_all_memory_range(struct range **rangep, int nodeid)
 388 {
 389         int i, count;
 390         u64 start = 0, end;
 391         u64 size;
 392         u64 mem;
 393         struct range *range;
 394         int nr_range;
 395
 396         count  = 0;
 397         for (i = 0; i < max_early_res && early_res[i].end; i++)
 398                 count++;
 399
 400         count *= 2;
 401
 402         size = sizeof(struct range) * count;
 403         end = get_max_mapped();
 404 #ifdef MAX_DMA32_PFN
 405         if (end > (MAX_DMA32_PFN << PAGE_SHIFT))
 406                 start = MAX_DMA32_PFN << PAGE_SHIFT;
 407 #endif
 408         mem = find_fw_memmap_area(start, end, size, sizeof(struct range));
 409         if (mem == -1ULL)
 410                 panic("can not find more space for range free");
 411
 412         range = __va(mem);
 413         /* use early_node_map[] and early_res to get range array at first */
 414         memset(range, 0, size);
 415         nr_range = 0;
 416
 417         /* need to go over early_node_map to find out good range for node */
 418         nr_range = add_from_early_node_map(range, count, nr_range, nodeid);
 419 #ifdef CONFIG_X86_32
 420         subtract_range(range, count, max_low_pfn, -1ULL);
 421 #endif
 422         subtract_early_res(range, count);
 423         nr_range = clean_sort_range(range, count);
 424
 425         /* need to clear it ? */
 426         if (nodeid == MAX_NUMNODES) {
 427                 memset(&early_res[0], 0,
 428                          sizeof(struct early_res) * max_early_res);
 429                 early_res = NULL;
 430                 max_early_res = 0;
 431         }
 432
 433         *rangep = range;
 434         return nr_range;
 435 }
 436 #else
 437 void __init early_res_to_bootmem(u64 start, u64 end)
 438 {
 439         int i, count;
 440         u64 final_start, final_end;
 441         int idx = 0;
 442
 443         count  = 0;
 444         for (i = 0; i < max_early_res && early_res[i].end; i++)
 445                 count++;
 446
 447         /* need to skip first one ?*/
 448         if (early_res != early_res_x)
 449                 idx = 1;
 450
 451         printk(KERN_INFO "(%d/%d early reservations) ==> bootmem [%010llx - %010llx]\n",
 452                          count - idx, max_early_res, start, end);
 453         for (i = idx; i < count; i++) {
 454                 struct early_res *r = &early_res[i];
 455                 printk(KERN_INFO "  #%d [%010llx - %010llx] %16s", i,
 456                         r->start, r->end, r->name);
 457                 final_start = max(start, r->start);
 458                 final_end = min(end, r->end);
 459                 if (final_start >= final_end) {
 460                         printk(KERN_CONT "\n");
 461                         continue;
 462                 }
 463                 printk(KERN_CONT " ==> [%010llx - %010llx]\n",
 464                         final_start, final_end);
 465                 reserve_bootmem_generic(final_start, final_end - final_start,
 466                                 BOOTMEM_DEFAULT);
 467         }
 468         /* clear them */
 469         memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);
 470         early_res = NULL;
 471         max_early_res = 0;
 472         early_res_count = 0;
 473 }
 474 #endif
 475
 476 /* Check for already reserved areas */
 477 static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
 478 {
 479         int i;
 480         u64 addr = *addrp;
 481         int changed = 0;
 482         struct early_res *r;
 483 again:
 484         i = find_overlapped_early(addr, addr + size);
 485         r = &early_res[i];
 486         if (i < max_early_res && r->end) {
 487                 *addrp = addr = round_up(r->end, align);
 488                 changed = 1;
 489                 goto again;
 490         }
 491         return changed;
 492 }
 493
 494 /* Check for already reserved areas */
 495 static inline int __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align)
 496 {
 497         int i;
 498         u64 addr = *addrp, last;
 499         u64 size = *sizep;
 500         int changed = 0;
 501 again:
 502         last = addr + size;
 503         for (i = 0; i < max_early_res && early_res[i].end; i++) {
 504                 struct early_res *r = &early_res[i];
 505                 if (last > r->start && addr < r->start) {
 506                         size = r->start - addr;
 507                         changed = 1;
 508                         goto again;
 509                 }
 510                 if (last > r->end && addr < r->end) {
 511                         addr = round_up(r->end, align);
 512                         size = last - addr;
 513                         changed = 1;
 514                         goto again;
 515                 }
 516                 if (last <= r->end && addr >= r->start) {
 517                         (*sizep)++;
 518                         return 0;
 519                 }
 520         }
 521         if (changed) {
 522                 *addrp = addr;
 523                 *sizep = size;
 524         }
 525         return changed;
 526 }
 527
 528 /*
 529  * Find a free area with specified alignment in a specific range.
 530  * only with the area.between start to end is active range from early_node_map
 531  * so they are good as RAM
 532  */
 533 u64 __init find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
 534                          u64 size, u64 align)
 535 {
 536         u64 addr, last;
 537
 538         addr = round_up(ei_start, align);
 539         if (addr < start)
 540                 addr = round_up(start, align);
 541         if (addr >= ei_last)
 542                 goto out;
 543         while (bad_addr(&addr, size, align) && addr+size <= ei_last)
 544                 ;
 545         last = addr + size;
 546         if (last > ei_last)
 547                 goto out;
 548         if (last > end)
 549                 goto out;
 550
 551         return addr;
 552
 553 out:
 554         return -1ULL;
 555 }
 556
 557 u64 __init find_early_area_size(u64 ei_start, u64 ei_last, u64 start,
 558                          u64 *sizep, u64 align)
 559 {
 560         u64 addr, last;
 561
 562         addr = round_up(ei_start, align);
 563         if (addr < start)
 564                 addr = round_up(start, align);
 565         if (addr >= ei_last)
 566                 goto out;
 567         *sizep = ei_last - addr;
 568         while (bad_addr_size(&addr, sizep, align) && addr + *sizep <= ei_last)
 569                 ;
 570         last = addr + *sizep;
 571         if (last > ei_last)
 572                 goto out;
 573
 574         return addr;
 575
 576 out:
 577         return -1ULL;
 578 }