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, u64 start_bad, u64 end_bad)
21 printk(KERN_INFO " %016llx bad mem addr %010llx - %010llx reserved\n",
22 (unsigned long long) pattern,
23 (unsigned long long) start_bad,
24 (unsigned long long) end_bad);
25 reserve_early(start_bad, end_bad, "BAD RAM");
28 static void __init memtest(u64 pattern, u64 start_phys, u64 size)
32 u64 start_bad, last_bad;
33 u64 start_phys_aligned;
36 incr = sizeof(pattern);
37 start_phys_aligned = ALIGN(start_phys, incr);
38 count = (size - (start_phys_aligned - start_phys))/incr;
39 start = __va(start_phys_aligned);
43 for (i = 0; i < count; i++)
45 for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
46 if (*start == pattern)
48 if (start_phys_aligned == last_bad + incr) {
53 reserve_bad_mem(pattern, start_bad, last_bad + incr);
54 start_bad = last_bad = start_phys_aligned;
57 reserve_bad_mem(pattern, start_bad, last_bad + incr);
60 /* default is disabled */
61 static int memtest_pattern __initdata;
63 static int __init parse_memtest(char *arg)
66 memtest_pattern = simple_strtoul(arg, NULL, 0);
70 early_param("memtest", parse_memtest);
72 void __init early_memtest(unsigned long start, unsigned long end)
81 printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
82 for (i = 0; i < memtest_pattern; i++) {
83 unsigned int idx = i % ARRAY_SIZE(patterns);
84 pattern = patterns[idx];
87 while (t_start < end) {
88 t_start = find_e820_area_size(t_start, &t_size, 1);
93 if (t_start + t_size > end)
94 t_size = end - t_start;
96 printk(KERN_INFO " %010llx - %010llx pattern %016llx\n",
97 (unsigned long long) t_start,
98 (unsigned long long) t_start + t_size,
99 (unsigned long long) cpu_to_be64(pattern));
100 memtest(pattern, t_start, t_size);