arch/x86/mm/memtest.c

   1 #include <linux/kernel.h>
   2 #include <linux/errno.h>
   3 #include <linux/string.h>
   4 #include <linux/types.h>
   5 #include <linux/mm.h>
   6 #include <linux/smp.h>
   7 #include <linux/init.h>
   8 #include <linux/pfn.h>
   9 #include <linux/memblock.h>
  10
  11 static u64 patterns[] __initdata = {
  12         0,
  13         0xffffffffffffffffULL,
  14         0x5555555555555555ULL,
  15         0xaaaaaaaaaaaaaaaaULL,
  16         0x1111111111111111ULL,
  17         0x2222222222222222ULL,
  18         0x4444444444444444ULL,
  19         0x8888888888888888ULL,
  20         0x3333333333333333ULL,
  21         0x6666666666666666ULL,
  22         0x9999999999999999ULL,
  23         0xccccccccccccccccULL,
  24         0x7777777777777777ULL,
  25         0xbbbbbbbbbbbbbbbbULL,
  26         0xddddddddddddddddULL,
  27         0xeeeeeeeeeeeeeeeeULL,
  28         0x7a6c7258554e494cULL, /* yeah ;-) */
  29 };
  30
  31 static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
  32 {
  33         printk(KERN_INFO "  %016llx bad mem addr %010llx - %010llx reserved\n",
  34                (unsigned long long) pattern,
  35                (unsigned long long) start_bad,
  36                (unsigned long long) end_bad);
  37         memblock_x86_reserve_range(start_bad, end_bad, "BAD RAM");
  38 }
  39
  40 static void __init memtest(u64 pattern, u64 start_phys, u64 size)
  41 {
  42         u64 *p, *start, *end;
  43         u64 start_bad, last_bad;
  44         u64 start_phys_aligned;
  45         const size_t incr = sizeof(pattern);
  46
  47         start_phys_aligned = ALIGN(start_phys, incr);
  48         start = __va(start_phys_aligned);
  49         end = start + (size - (start_phys_aligned - start_phys)) / incr;
  50         start_bad = 0;
  51         last_bad = 0;
  52
  53         for (p = start; p < end; p++)
  54                 *p = pattern;
  55
  56         for (p = start; p < end; p++, start_phys_aligned += incr) {
  57                 if (*p == pattern)
  58                         continue;
  59                 if (start_phys_aligned == last_bad + incr) {
  60                         last_bad += incr;
  61                         continue;
  62                 }
  63                 if (start_bad)
  64                         reserve_bad_mem(pattern, start_bad, last_bad + incr);
  65                 start_bad = last_bad = start_phys_aligned;
  66         }
  67         if (start_bad)
  68                 reserve_bad_mem(pattern, start_bad, last_bad + incr);
  69 }
  70
  71 static void __init do_one_pass(u64 pattern, u64 start, u64 end)
  72 {
  73         u64 size = 0;
  74
  75         while (start < end) {
  76                 start = memblock_x86_find_in_range_size(start, &size, 1);
  77
  78                 /* done ? */
  79                 if (start >= end)
  80                         break;
  81                 if (start + size > end)
  82                         size = end - start;
  83
  84                 printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
  85                        (unsigned long long) start,
  86                        (unsigned long long) start + size,
  87                        (unsigned long long) cpu_to_be64(pattern));
  88                 memtest(pattern, start, size);
  89
  90                 start += size;
  91         }
  92 }
  93
  94 /* default is disabled */
  95 static int memtest_pattern __initdata;
  96
  97 static int __init parse_memtest(char *arg)
  98 {
  99         if (arg)
 100                 memtest_pattern = simple_strtoul(arg, NULL, 0);
 101         else
 102                 memtest_pattern = ARRAY_SIZE(patterns);
 103
 104         return 0;
 105 }
 106
 107 early_param("memtest", parse_memtest);
 108
 109 void __init early_memtest(unsigned long start, unsigned long end)
 110 {
 111         unsigned int i;
 112         unsigned int idx = 0;
 113
 114         if (!memtest_pattern)
 115                 return;
 116
 117         printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
 118         for (i = 0; i < memtest_pattern; i++) {
 119                 idx = i % ARRAY_SIZE(patterns);
 120                 do_one_pass(patterns[idx], start, end);
 121         }
 122
 123         if (idx > 0) {
 124                 printk(KERN_INFO "early_memtest: wipe out "
 125                        "test pattern from memory\n");
 126                 /* additional test with pattern 0 will do this */
 127                 do_one_pass(0, start, end);
 128         }
 129 }