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 bool __init memblock_x86_check_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 (memblock_x86_check_reserved_size(&addr, sizep, align))
  63                         ;
  64
  65                 if (*sizep)
  66                         return addr;
  67         }
  68
  69         return 0;
  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)
  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 static int __init count_early_node_map(int nodeid)
 119 {
 120         int i, cnt = 0;
 121
 122         for_each_mem_pfn_range(i, nodeid, NULL, NULL, NULL)
 123                 cnt++;
 124         return cnt;
 125 }
 126
 127 int __init __get_free_all_memory_range(struct range **rangep, int nodeid,
 128                          unsigned long start_pfn, unsigned long end_pfn)
 129 {
 130         int count;
 131         struct range *range;
 132         int nr_range;
 133
 134         count = (memblock.reserved.cnt + count_early_node_map(nodeid)) * 2;
 135
 136         range = find_range_array(count);
 137         nr_range = 0;
 138
 139         /*
 140          * Use early_node_map[] and memblock.reserved.region to get range array
 141          * at first
 142          */
 143         nr_range = add_from_early_node_map(range, count, nr_range, nodeid);
 144         subtract_range(range, count, 0, start_pfn);
 145         subtract_range(range, count, end_pfn, -1ULL);
 146
 147         memblock_x86_subtract_reserved(range, count);
 148         nr_range = clean_sort_range(range, count);
 149
 150         *rangep = range;
 151         return nr_range;
 152 }
 153
 154 int __init get_free_all_memory_range(struct range **rangep, int nodeid)
 155 {
 156         unsigned long end_pfn = -1UL;
 157
 158 #ifdef CONFIG_X86_32
 159         end_pfn = max_low_pfn;
 160 #endif
 161         return __get_free_all_memory_range(rangep, nodeid, 0, end_pfn);
 162 }
 163
 164 static u64 __init __memblock_x86_memory_in_range(u64 addr, u64 limit, bool get_free)
 165 {
 166         int i, count;
 167         struct range *range;
 168         int nr_range;
 169         u64 final_start, final_end;
 170         u64 free_size;
 171         struct memblock_region *r;
 172
 173         count = (memblock.reserved.cnt + memblock.memory.cnt) * 2;
 174
 175         range = find_range_array(count);
 176         nr_range = 0;
 177
 178         addr = PFN_UP(addr);
 179         limit = PFN_DOWN(limit);
 180
 181         for_each_memblock(memory, r) {
 182                 final_start = PFN_UP(r->base);
 183                 final_end = PFN_DOWN(r->base + r->size);
 184                 if (final_start >= final_end)
 185                         continue;
 186                 if (final_start >= limit || final_end <= addr)
 187                         continue;
 188
 189                 nr_range = add_range(range, count, nr_range, final_start, final_end);
 190         }
 191         subtract_range(range, count, 0, addr);
 192         subtract_range(range, count, limit, -1ULL);
 193
 194         /* Subtract memblock.reserved.region in range ? */
 195         if (!get_free)
 196                 goto sort_and_count_them;
 197         for_each_memblock(reserved, r) {
 198                 final_start = PFN_DOWN(r->base);
 199                 final_end = PFN_UP(r->base + r->size);
 200                 if (final_start >= final_end)
 201                         continue;
 202                 if (final_start >= limit || final_end <= addr)
 203                         continue;
 204
 205                 subtract_range(range, count, final_start, final_end);
 206         }
 207
 208 sort_and_count_them:
 209         nr_range = clean_sort_range(range, count);
 210
 211         free_size = 0;
 212         for (i = 0; i < nr_range; i++)
 213                 free_size += range[i].end - range[i].start;
 214
 215         return free_size << PAGE_SHIFT;
 216 }
 217
 218 u64 __init memblock_x86_free_memory_in_range(u64 addr, u64 limit)
 219 {
 220         return __memblock_x86_memory_in_range(addr, limit, true);
 221 }
 222
 223 u64 __init memblock_x86_memory_in_range(u64 addr, u64 limit)
 224 {
 225         return __memblock_x86_memory_in_range(addr, limit, false);
 226 }
 227
 228 void __init memblock_x86_reserve_range(u64 start, u64 end, char *name)
 229 {
 230         if (start == end)
 231                 return;
 232
 233         if (WARN_ONCE(start > end, "memblock_x86_reserve_range: wrong range [%#llx, %#llx)\n", start, end))
 234                 return;
 235
 236         memblock_dbg("    memblock_x86_reserve_range: [%#010llx-%#010llx] %16s\n", start, end - 1, name);
 237
 238         memblock_reserve(start, end - start);
 239 }
 240
 241 void __init memblock_x86_free_range(u64 start, u64 end)
 242 {
 243         if (start == end)
 244                 return;
 245
 246         if (WARN_ONCE(start > end, "memblock_x86_free_range: wrong range [%#llx, %#llx)\n", start, end))
 247                 return;
 248
 249         memblock_dbg("       memblock_x86_free_range: [%#010llx-%#010llx]\n", start, end - 1);
 250
 251         memblock_free(start, end - start);
 252 }
 253
 254 /*
 255  * Finds an active region in the address range from start_pfn to last_pfn and
 256  * returns its range in ei_startpfn and ei_endpfn for the memblock entry.
 257  */
 258 static int __init memblock_x86_find_active_region(const struct memblock_region *ei,
 259                                   unsigned long start_pfn,
 260                                   unsigned long last_pfn,
 261                                   unsigned long *ei_startpfn,
 262                                   unsigned long *ei_endpfn)
 263 {
 264         u64 align = PAGE_SIZE;
 265
 266         *ei_startpfn = round_up(ei->base, align) >> PAGE_SHIFT;
 267         *ei_endpfn = round_down(ei->base + ei->size, align) >> PAGE_SHIFT;
 268
 269         /* Skip map entries smaller than a page */
 270         if (*ei_startpfn >= *ei_endpfn)
 271                 return 0;
 272
 273         /* Skip if map is outside the node */
 274         if (*ei_endpfn <= start_pfn || *ei_startpfn >= last_pfn)
 275                 return 0;
 276
 277         /* Check for overlaps */
 278         if (*ei_startpfn < start_pfn)
 279                 *ei_startpfn = start_pfn;
 280         if (*ei_endpfn > last_pfn)
 281                 *ei_endpfn = last_pfn;
 282
 283         return 1;
 284 }
 285
 286 /*
 287  * Find the hole size (in bytes) in the memory range.
 288  * @start: starting address of the memory range to scan
 289  * @end: ending address of the memory range to scan
 290  */
 291 u64 __init memblock_x86_hole_size(u64 start, u64 end)
 292 {
 293         unsigned long start_pfn = start >> PAGE_SHIFT;
 294         unsigned long last_pfn = end >> PAGE_SHIFT;
 295         unsigned long ei_startpfn, ei_endpfn, ram = 0;
 296         struct memblock_region *r;
 297
 298         for_each_memblock(memory, r)
 299                 if (memblock_x86_find_active_region(r, start_pfn, last_pfn,
 300                                            &ei_startpfn, &ei_endpfn))
 301                         ram += ei_endpfn - ei_startpfn;
 302
 303         return end - start - ((u64)ram << PAGE_SHIFT);
 304 }