1 #include <linux/kernel.h>
2 #include <linux/errno.h>
3 #include <linux/string.h>
4 #include <linux/types.h>
7 #include <linux/init.h>
9 #include <linux/memblock.h>
11 static u64 patterns[] __initdata = {
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 ;-) */
31 static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
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");
40 static void __init memtest(u64 pattern, u64 start_phys, u64 size)
43 u64 start_bad, last_bad;
44 u64 start_phys_aligned;
45 const size_t incr = sizeof(pattern);
47 start_phys_aligned = ALIGN(start_phys, incr);
48 start = __va(start_phys_aligned);
49 end = start + (size - (start_phys_aligned - start_phys)) / incr;
53 for (p = start; p < end; p++)
56 for (p = start; p < end; p++, start_phys_aligned += incr) {
59 if (start_phys_aligned == last_bad + incr) {
64 reserve_bad_mem(pattern, start_bad, last_bad + incr);
65 start_bad = last_bad = start_phys_aligned;
68 reserve_bad_mem(pattern, start_bad, last_bad + incr);
71 static void __init do_one_pass(u64 pattern, u64 start, u64 end)
76 start = memblock_x86_find_in_range_size(start, &size, 1);
81 if (start + size > end)
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);
94 /* default is disabled */
95 static int memtest_pattern __initdata;
97 static int __init parse_memtest(char *arg)
100 memtest_pattern = simple_strtoul(arg, NULL, 0);
102 memtest_pattern = ARRAY_SIZE(patterns);
107 early_param("memtest", parse_memtest);
109 void __init early_memtest(unsigned long start, unsigned long end)
112 unsigned int idx = 0;
114 if (!memtest_pattern)
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);
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);