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 memtest(unsigned long start_phys, unsigned long size,
  20                            u64 pattern)
  21 {
  22         unsigned long i;
  23         u64 *start;
  24         unsigned long start_bad;
  25         unsigned long last_bad;
  26         unsigned long start_phys_aligned;
  27         unsigned long count;
  28         unsigned long incr;
  29
  30         incr = sizeof(pattern);
  31         start_phys_aligned = ALIGN(start_phys, incr);
  32         count = (size - (start_phys_aligned - start_phys))/incr;
  33         start = __va(start_phys_aligned);
  34         start_bad = 0;
  35         last_bad = 0;
  36
  37         for (i = 0; i < count; i++)
  38                 start[i] = pattern;
  39         for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
  40                 if (*start != pattern) {
  41                         if (start_phys_aligned == last_bad + incr) {
  42                                 last_bad += incr;
  43                         } else {
  44                                 if (start_bad) {
  45                                         printk(KERN_CONT "\n  %016llx bad mem addr %010lx - %010lx reserved",
  46                                                (unsigned long long) pattern,
  47                                                start_bad, last_bad + incr);
  48                                         reserve_early(start_bad, last_bad + incr, "BAD RAM");
  49                                 }
  50                                 start_bad = last_bad = start_phys_aligned;
  51                         }
  52                 }
  53         }
  54         if (start_bad) {
  55                 printk(KERN_CONT "\n  %016llx bad mem addr %010lx - %010lx reserved",
  56                        (unsigned long long) pattern, start_bad,
  57                        last_bad + incr);
  58                 reserve_early(start_bad, last_bad + incr, "BAD RAM");
  59         }
  60 }
  61
  62 /* default is disabled */
  63 static int memtest_pattern __initdata;
  64
  65 static int __init parse_memtest(char *arg)
  66 {
  67         if (arg)
  68                 memtest_pattern = simple_strtoul(arg, NULL, 0);
  69         return 0;
  70 }
  71
  72 early_param("memtest", parse_memtest);
  73
  74 void __init early_memtest(unsigned long start, unsigned long end)
  75 {
  76         u64 t_start, t_size;
  77         unsigned int i;
  78         u64 pattern;
  79
  80         if (!memtest_pattern)
  81                 return;
  82
  83         printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
  84         for (i = 0; i < memtest_pattern; i++) {
  85                 unsigned int idx = i % ARRAY_SIZE(patterns);
  86                 pattern = patterns[idx];
  87                 t_start = start;
  88                 t_size = 0;
  89                 while (t_start < end) {
  90                         t_start = find_e820_area_size(t_start, &t_size, 1);
  91
  92                         /* done ? */
  93                         if (t_start >= end)
  94                                 break;
  95                         if (t_start + t_size > end)
  96                                 t_size = end - t_start;
  97
  98                         printk(KERN_CONT "\n  %010llx - %010llx pattern %d",
  99                                (unsigned long long)t_start,
 100                                (unsigned long long)t_start + t_size, idx);
 101
 102                         memtest(t_start, t_size, pattern);
 103
 104                         t_start += t_size;
 105                 }
 106         }
 107         printk(KERN_CONT "\n");
 108 }