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>
12 static u64 patterns[] __initdata = {
14 0xffffffffffffffffULL,
15 0x5555555555555555ULL,
16 0xaaaaaaaaaaaaaaaaULL,
19 static void __init reserve_bad_mem(u64 pattern, unsigned long start_bad,
20 unsigned long end_bad)
22 printk(KERN_CONT "\n %016llx bad mem addr "
23 "%010lx - %010lx reserved",
24 (unsigned long long) pattern, start_bad, end_bad);
25 reserve_early(start_bad, end_bad, "BAD RAM");
28 static void __init memtest(unsigned long start_phys, unsigned long size,
33 unsigned long start_bad;
34 unsigned long last_bad;
35 unsigned long start_phys_aligned;
39 incr = sizeof(pattern);
40 start_phys_aligned = ALIGN(start_phys, incr);
41 count = (size - (start_phys_aligned - start_phys))/incr;
42 start = __va(start_phys_aligned);
46 for (i = 0; i < count; i++)
48 for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
49 if (*start == pattern)
51 if (start_phys_aligned == last_bad + incr) {
56 reserve_bad_mem(pattern, start_bad, last_bad + incr);
57 start_bad = last_bad = start_phys_aligned;
60 reserve_bad_mem(pattern, start_bad, last_bad + incr);
63 /* default is disabled */
64 static int memtest_pattern __initdata;
66 static int __init parse_memtest(char *arg)
69 memtest_pattern = simple_strtoul(arg, NULL, 0);
73 early_param("memtest", parse_memtest);
75 void __init early_memtest(unsigned long start, unsigned long end)
84 printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
85 for (i = 0; i < memtest_pattern; i++) {
86 unsigned int idx = i % ARRAY_SIZE(patterns);
87 pattern = patterns[idx];
90 while (t_start < end) {
91 t_start = find_e820_area_size(t_start, &t_size, 1);
96 if (t_start + t_size > end)
97 t_size = end - t_start;
99 printk(KERN_CONT "\n %010llx - %010llx pattern %d",
100 (unsigned long long)t_start,
101 (unsigned long long)t_start + t_size, idx);
103 memtest(t_start, t_size, pattern);
108 printk(KERN_CONT "\n");