LXR linux/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
  12static u64 patterns[] __initdata = {
  13        0,
  14        0xffffffffffffffffULL,
  15        0x5555555555555555ULL,
  16        0xaaaaaaaaaaaaaaaaULL,
  17        0x1111111111111111ULL,
  18        0x2222222222222222ULL,
  19        0x4444444444444444ULL,
  20        0x8888888888888888ULL,
  21        0x3333333333333333ULL,
  22        0x6666666666666666ULL,
  23        0x9999999999999999ULL,
  24        0xccccccccccccccccULL,
  25        0x7777777777777777ULL,
  26        0xbbbbbbbbbbbbbbbbULL,
  27        0xddddddddddddddddULL,
  28        0xeeeeeeeeeeeeeeeeULL,
  29        0x7a6c7258554e494cULL, /* yeah ;-) */
  30};
  31
  32static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
  33{
  34        printk(KERN_INFO "  %016llx bad mem addr %010llx - %010llx reserved\n",
  35               (unsigned long long) pattern,
  36               (unsigned long long) start_bad,
  37               (unsigned long long) end_bad);
  38        reserve_early(start_bad, end_bad, "BAD RAM");
  39}
  40
  41static void __init memtest(u64 pattern, u64 start_phys, u64 size)
  42{
  43        u64 *p, *start, *end;
  44        u64 start_bad, last_bad;
  45        u64 start_phys_aligned;
  46        const size_t incr = sizeof(pattern);
  47
  48        start_phys_aligned = ALIGN(start_phys, incr);
  49        start = __va(start_phys_aligned);
  50        end = start + (size - (start_phys_aligned - start_phys)) / incr;
  51        start_bad = 0;
  52        last_bad = 0;
  53
  54        for (p = start; p < end; p++)
  55                *p = pattern;
  56
  57        for (p = start; p < end; p++, start_phys_aligned += incr) {
  58                if (*p == pattern)
  59                        continue;
  60                if (start_phys_aligned == last_bad + incr) {
  61                        last_bad += incr;
  62                        continue;
  63                }
  64                if (start_bad)
  65                        reserve_bad_mem(pattern, start_bad, last_bad + incr);
  66                start_bad = last_bad = start_phys_aligned;
  67        }
  68        if (start_bad)
  69                reserve_bad_mem(pattern, start_bad, last_bad + incr);
  70}
  71
  72static void __init do_one_pass(u64 pattern, u64 start, u64 end)
  73{
  74        u64 size = 0;
  75
  76        while (start < end) {
  77                start = find_e820_area_size(start, &size, 1);
  78
  79                /* done ? */
  80                if (start >= end)
  81                        break;
  82                if (start + size > end)
  83                        size = end - start;
  84
  85                printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
  86                       (unsigned long long) start,
  87                       (unsigned long long) start + size,
  88                       (unsigned long long) cpu_to_be64(pattern));
  89                memtest(pattern, start, size);
  90
  91                start += size;
  92        }
  93}
  94
  95/* default is disabled */
  96static int memtest_pattern __initdata;
  97
  98static int __init parse_memtest(char *arg)
  99{
 100        if (arg)
 101                memtest_pattern = simple_strtoul(arg, NULL, 0);
 102        else
 103                memtest_pattern = ARRAY_SIZE(patterns);
 104
 105        return 0;
 106}
 107
 108early_param("memtest", parse_memtest);
 109
 110void __init early_memtest(unsigned long start, unsigned long end)
 111{
 112        unsigned int i;
 113        unsigned int idx = 0;
 114
 115        if (!memtest_pattern)
 116                return;
 117
 118        printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
 119        for (i = 0; i < memtest_pattern; i++) {
 120                idx = i % ARRAY_SIZE(patterns);
 121                do_one_pass(patterns[idx], start, end);
 122        }
 123
 124        if (idx > 0) {
 125                printk(KERN_INFO "early_memtest: wipe out "
 126                       "test pattern from memory\n");
 127                /* additional test with pattern 0 will do this */
 128                do_one_pass(0, start, end);
 129        }
 130}
 131