arch/x86/mm/memblock.c

   1 #include <linux/kernel.h>
   2 #include <linux/types.h>
   3 #include <linux/init.h>
   4 #include <linux/bitops.h>
   5 #include <linux/memblock.h>
   6 #include <linux/bootmem.h>
   7 #include <linux/mm.h>
   8 #include <linux/range.h>
   9
  10 /* Check for already reserved areas */
  11 static bool __init check_with_memblock_reserved_size(u64 *addrp, u64 *sizep, u64 align)
  12 {
  13         struct memblock_region *r;
  14         u64 addr = *addrp, last;
  15         u64 size = *sizep;
  16         bool changed = false;
  17
  18 again:
  19         last = addr + size;
  20         for_each_memblock(reserved, r) {
  21                 if (last > r->base && addr < r->base) {
  22                         size = r->base - addr;
  23                         changed = true;
  24                         goto again;
  25                 }
  26                 if (last > (r->base + r->size) && addr < (r->base + r->size)) {
  27                         addr = round_up(r->base + r->size, align);
  28                         size = last - addr;
  29                         changed = true;
  30                         goto again;
  31                 }
  32                 if (last <= (r->base + r->size) && addr >= r->base) {
  33                         *sizep = 0;
  34                         return false;
  35                 }
  36         }
  37         if (changed) {
  38                 *addrp = addr;
  39                 *sizep = size;
  40         }
  41         return changed;
  42 }
  43
  44 /*
  45  * Find next free range after start, and size is returned in *sizep
  46  */
  47 u64 __init memblock_x86_find_in_range_size(u64 start, u64 *sizep, u64 align)
  48 {
  49         struct memblock_region *r;
  50
  51         for_each_memblock(memory, r) {
  52                 u64 ei_start = r->base;
  53                 u64 ei_last = ei_start + r->size;
  54                 u64 addr;
  55
  56                 addr = round_up(ei_start, align);
  57                 if (addr < start)
  58                         addr = round_up(start, align);
  59                 if (addr >= ei_last)
  60                         continue;
  61                 *sizep = ei_last - addr;
  62                 while (check_with_memblock_reserved_size(&addr, sizep, align))
  63                         ;
  64
  65                 if (*sizep)
  66                         return addr;
  67         }
  68
  69         return MEMBLOCK_ERROR;
  70 }
  71
  72 static __init struct range *find_range_array(int count)
  73 {
  74         u64 end, size, mem;
  75         struct range *range;
  76
  77         size = sizeof(struct range) * count;
  78         end = memblock.current_limit;
  79
  80         mem = memblock_find_in_range(0, end, size, sizeof(struct range));
  81         if (mem == MEMBLOCK_ERROR)
  82                 panic("can not find more space for range array");
  83
  84         /*
  85          * This range is tempoaray, so don't reserve it, it will not be
  86          * overlapped because We will not alloccate new buffer before
  87          * We discard this one
  88          */
  89         range = __va(mem);
  90         memset(range, 0, size);
  91
  92         return range;
  93 }
  94
  95 static void __init memblock_x86_subtract_reserved(struct range *range, int az)
  96 {
  97         u64 final_start, final_end;
  98         struct memblock_region *r;
  99
 100         /* Take out region array itself at first*/
 101         memblock_free_reserved_regions();
 102
 103         memblock_dbg("Subtract (%ld early reservations)\n", memblock.reserved.cnt);
 104
 105         for_each_memblock(reserved, r) {
 106                 memblock_dbg("  [%010llx-%010llx]\n", (u64)r->base, (u64)r->base + r->size - 1);
 107                 final_start = PFN_DOWN(r->base);
 108                 final_end = PFN_UP(r->base + r->size);
 109                 if (final_start >= final_end)
 110                         continue;
 111                 subtract_range(range, az, final_start, final_end);
 112         }
 113
 114         /* Put region array back ? */
 115         memblock_reserve_reserved_regions();
 116 }
 117
 118 struct count_data {
 119         int nr;
 120 };
 121
 122 static int __init count_work_fn(unsigned long start_pfn,
 123                                 unsigned long end_pfn, void *datax)
 124 {
 125         struct count_data *data = datax;
 126
 127         data->nr++;
 128
 129         return 0;
 130 }
 131
 132 static int __init count_early_node_map(int nodeid)
 133 {
 134         struct count_data data;
 135
 136         data.nr = 0;
 137         work_with_active_regions(nodeid, count_work_fn, &data);
 138
 139         return data.nr;
 140 }
 141
 142 int __init __get_free_all_memory_range(struct range **rangep, int nodeid,
 143                          unsigned long start_pfn, unsigned long end_pfn)
 144 {
 145         int count;
 146         struct range *range;
 147         int nr_range;
 148
 149         count = (memblock.reserved.cnt + count_early_node_map(nodeid)) * 2;
 150
 151         range = find_range_array(count);
 152         nr_range = 0;
 153
 154         /*
 155          * Use early_node_map[] and memblock.reserved.region to get range array
 156          * at first
 157          */
 158         nr_range = add_from_early_node_map(range, count, nr_range, nodeid);
 159         subtract_range(range, count, 0, start_pfn);
 160         subtract_range(range, count, end_pfn, -1ULL);
 161
 162         memblock_x86_subtract_reserved(range, count);
 163         nr_range = clean_sort_range(range, count);
 164
 165         *rangep = range;
 166         return nr_range;
 167 }
 168
 169 int __init get_free_all_memory_range(struct range **rangep, int nodeid)
 170 {
 171         unsigned long end_pfn = -1UL;
 172
 173 #ifdef CONFIG_X86_32
 174         end_pfn = max_low_pfn;
 175 #endif
 176         return __get_free_all_memory_range(rangep, nodeid, 0, end_pfn);
 177 }
 178
 179 static u64 __init __memblock_x86_memory_in_range(u64 addr, u64 limit, bool get_free)
 180 {
 181         int i, count;
 182         struct range *range;
 183         int nr_range;
 184         u64 final_start, final_end;
 185         u64 free_size;
 186         struct memblock_region *r;
 187
 188         count = (memblock.reserved.cnt + memblock.memory.cnt) * 2;
 189
 190         range = find_range_array(count);
 191         nr_range = 0;
 192
 193         addr = PFN_UP(addr);
 194         limit = PFN_DOWN(limit);
 195
 196         for_each_memblock(memory, r) {
 197                 final_start = PFN_UP(r->base);
 198                 final_end = PFN_DOWN(r->base + r->size);
 199                 if (final_start >= final_end)
 200                         continue;
 201                 if (final_start >= limit || final_end <= addr)
 202                         continue;
 203
 204                 nr_range = add_range(range, count, nr_range, final_start, final_end);
 205         }
 206         subtract_range(range, count, 0, addr);
 207         subtract_range(range, count, limit, -1ULL);
 208
 209         /* Subtract memblock.reserved.region in range ? */
 210         if (!get_free)
 211                 goto sort_and_count_them;
 212         for_each_memblock(reserved, r) {
 213                 final_start = PFN_DOWN(r->base);
 214                 final_end = PFN_UP(r->base + r->size);
 215                 if (final_start >= final_end)
 216                         continue;
 217                 if (final_start >= limit || final_end <= addr)
 218                         continue;
 219
 220                 subtract_range(range, count, final_start, final_end);
 221         }
 222
 223 sort_and_count_them:
 224         nr_range = clean_sort_range(range, count);
 225
 226         free_size = 0;
 227         for (i = 0; i < nr_range; i++)
 228                 free_size += range[i].end - range[i].start;
 229
 230         return free_size << PAGE_SHIFT;
 231 }
 232
 233 u64 __init memblock_x86_free_memory_in_range(u64 addr, u64 limit)
 234 {
 235         return __memblock_x86_memory_in_range(addr, limit, true);
 236 }
 237
 238 u64 __init memblock_x86_memory_in_range(u64 addr, u64 limit)
 239 {
 240         return __memblock_x86_memory_in_range(addr, limit, false);
 241 }
 242
 243 void __init memblock_x86_reserve_range(u64 start, u64 end, char *name)
 244 {
 245         if (start == end)
 246                 return;
 247
 248         if (WARN_ONCE(start > end, "memblock_x86_reserve_range: wrong range [%#llx, %#llx)\n", start, end))
 249                 return;
 250
 251         memblock_dbg("    memblock_x86_reserve_range: [%#010llx-%#010llx] %16s\n", start, end - 1, name);
 252
 253         memblock_reserve(start, end - start);
 254 }
 255
 256 void __init memblock_x86_free_range(u64 start, u64 end)
 257 {
 258         if (start == end)
 259                 return;
 260
 261         if (WARN_ONCE(start > end, "memblock_x86_free_range: wrong range [%#llx, %#llx)\n", start, end))
 262                 return;
 263
 264         memblock_dbg("       memblock_x86_free_range: [%#010llx-%#010llx]\n", start, end - 1);
 265
 266         memblock_free(start, end - start);
 267 }
 268
 269 /*
 270  * Need to call this function after memblock_x86_register_active_regions,
 271  * so early_node_map[] is filled already.
 272  */
 273 u64 __init memblock_x86_find_in_range_node(int nid, u64 start, u64 end, u64 size, u64 align)
 274 {
 275         u64 addr;
 276         addr = find_memory_core_early(nid, size, align, start, end);
 277         if (addr != MEMBLOCK_ERROR)
 278                 return addr;
 279
 280         /* Fallback, should already have start end within node range */
 281         return memblock_find_in_range(start, end, size, align);
 282 }
 283
 284 /*
 285  * Finds an active region in the address range from start_pfn to last_pfn and
 286  * returns its range in ei_startpfn and ei_endpfn for the memblock entry.
 287  */
 288 static int __init memblock_x86_find_active_region(const struct memblock_region *ei,
 289                                   unsigned long start_pfn,
 290                                   unsigned long last_pfn,
 291                                   unsigned long *ei_startpfn,
 292                                   unsigned long *ei_endpfn)
 293 {
 294         u64 align = PAGE_SIZE;
 295
 296         *ei_startpfn = round_up(ei->base, align) >> PAGE_SHIFT;
 297         *ei_endpfn = round_down(ei->base + ei->size, align) >> PAGE_SHIFT;
 298
 299         /* Skip map entries smaller than a page */
 300         if (*ei_startpfn >= *ei_endpfn)
 301                 return 0;
 302
 303         /* Skip if map is outside the node */
 304         if (*ei_endpfn <= start_pfn || *ei_startpfn >= last_pfn)
 305                 return 0;
 306
 307         /* Check for overlaps */
 308         if (*ei_startpfn < start_pfn)
 309                 *ei_startpfn = start_pfn;
 310         if (*ei_endpfn > last_pfn)
 311                 *ei_endpfn = last_pfn;
 312
 313         return 1;
 314 }
 315
 316 /* Walk the memblock.memory map and register active regions within a node */
 317 void __init memblock_x86_register_active_regions(int nid, unsigned long start_pfn,
 318                                          unsigned long last_pfn)
 319 {
 320         unsigned long ei_startpfn;
 321         unsigned long ei_endpfn;
 322         struct memblock_region *r;
 323
 324         for_each_memblock(memory, r)
 325                 if (memblock_x86_find_active_region(r, start_pfn, last_pfn,
 326                                            &ei_startpfn, &ei_endpfn))
 327                         add_active_range(nid, ei_startpfn, ei_endpfn);
 328 }
 329
 330 /*
 331  * Find the hole size (in bytes) in the memory range.
 332  * @start: starting address of the memory range to scan
 333  * @end: ending address of the memory range to scan
 334  */
 335 u64 __init memblock_x86_hole_size(u64 start, u64 end)
 336 {
 337         unsigned long start_pfn = start >> PAGE_SHIFT;
 338         unsigned long last_pfn = end >> PAGE_SHIFT;
 339         unsigned long ei_startpfn, ei_endpfn, ram = 0;
 340         struct memblock_region *r;
 341
 342         for_each_memblock(memory, r)
 343                 if (memblock_x86_find_active_region(r, start_pfn, last_pfn,
 344                                            &ei_startpfn, &ei_endpfn))
 345                         ram += ei_endpfn - ei_startpfn;
 346
 347         return end - start - ((u64)ram << PAGE_SHIFT);
 348 }