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#include <linux/memblock.h>
  10
  11static 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
  31static 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
  40static 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
  71static 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 */
  95static int memtest_pattern __initdata;
  96
  97static 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
 107early_param("memtest", parse_memtest);
 108
 109void __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}
 130