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        /* The first entry has to be 0 to leave memtest with zeroed memory */
  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        memblock_reserve(start_bad, end_bad - start_bad);
  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 i;
  75        phys_addr_t this_start, this_end;
  76
  77        for_each_free_mem_range(i, MAX_NUMNODES, &this_start, &this_end, NULL) {
  78                this_start = clamp_t(phys_addr_t, this_start, start, end);
  79                this_end = clamp_t(phys_addr_t, this_end, start, end);
  80                if (this_start < this_end) {
  81                        printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
  82                               (unsigned long long)this_start,
  83                               (unsigned long long)this_end,
  84                               (unsigned long long)cpu_to_be64(pattern));
  85                        memtest(pattern, this_start, this_end - this_start);
  86                }
  87        }
  88}
  89
  90/* default is disabled */
  91static int memtest_pattern __initdata;
  92
  93static int __init parse_memtest(char *arg)
  94{
  95        if (arg)
  96                memtest_pattern = simple_strtoul(arg, NULL, 0);
  97        else
  98                memtest_pattern = ARRAY_SIZE(patterns);
  99
 100        return 0;
 101}
 102
 103early_param("memtest", parse_memtest);
 104
 105void __init early_memtest(unsigned long start, unsigned long end)
 106{
 107        unsigned int i;
 108        unsigned int idx = 0;
 109
 110        if (!memtest_pattern)
 111                return;
 112
 113        printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
 114        for (i = memtest_pattern-1; i < UINT_MAX; --i) {
 115                idx = i % ARRAY_SIZE(patterns);
 116                do_one_pass(patterns[idx], start, end);
 117        }
 118}
 119