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
  10 #include <asm/e820.h>
  11
  12 static u64 patterns[] __initdata = {
  13         0,
  14         0xffffffffffffffffULL,
  15         0x5555555555555555ULL,
  16         0xaaaaaaaaaaaaaaaaULL,
  17 };
  18
  19 static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
  20 {
  21         printk(KERN_INFO "  %016llx bad mem addr %010llx - %010llx reserved\n",
  22                (unsigned long long) pattern,
  23                (unsigned long long) start_bad,
  24                (unsigned long long) end_bad);
  25         reserve_early(start_bad, end_bad, "BAD RAM");
  26 }
  27
  28 static void __init memtest(u64 pattern, u64 start_phys, u64 size)
  29 {
  30         u64 i, count;
  31         u64 *start;
  32         u64 start_bad, last_bad;
  33         u64 start_phys_aligned;
  34         size_t incr;
  35
  36         incr = sizeof(pattern);
  37         start_phys_aligned = ALIGN(start_phys, incr);
  38         count = (size - (start_phys_aligned - start_phys))/incr;
  39         start = __va(start_phys_aligned);
  40         start_bad = 0;
  41         last_bad = 0;
  42
  43         for (i = 0; i < count; i++)
  44                 start[i] = pattern;
  45         for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
  46                 if (*start == pattern)
  47                         continue;
  48                 if (start_phys_aligned == last_bad + incr) {
  49                         last_bad += incr;
  50                         continue;
  51                 }
  52                 if (start_bad)
  53                         reserve_bad_mem(pattern, start_bad, last_bad + incr);
  54                 start_bad = last_bad = start_phys_aligned;
  55         }
  56         if (start_bad)
  57                 reserve_bad_mem(pattern, start_bad, last_bad + incr);
  58 }
  59
  60 /* default is disabled */
  61 static int memtest_pattern __initdata;
  62
  63 static int __init parse_memtest(char *arg)
  64 {
  65         if (arg)
  66                 memtest_pattern = simple_strtoul(arg, NULL, 0);
  67         return 0;
  68 }
  69
  70 early_param("memtest", parse_memtest);
  71
  72 void __init early_memtest(unsigned long start, unsigned long end)
  73 {
  74         u64 t_start, t_size;
  75         unsigned int i;
  76         u64 pattern;
  77
  78         if (!memtest_pattern)
  79                 return;
  80
  81         printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
  82         for (i = 0; i < memtest_pattern; i++) {
  83                 unsigned int idx = i % ARRAY_SIZE(patterns);
  84                 pattern = patterns[idx];
  85                 t_start = start;
  86                 t_size = 0;
  87                 while (t_start < end) {
  88                         t_start = find_e820_area_size(t_start, &t_size, 1);
  89
  90                         /* done ? */
  91                         if (t_start >= end)
  92                                 break;
  93                         if (t_start + t_size > end)
  94                                 t_size = end - t_start;
  95
  96                         printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
  97                                (unsigned long long) t_start,
  98                                (unsigned long long) t_start + t_size,
  99                                (unsigned long long) cpu_to_be64(pattern));
 100                         memtest(pattern, t_start, t_size);
 101
 102                         t_start += t_size;
 103                 }
 104         }
 105 }