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_reserve(start_bad, end_bad - start_bad);
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 i;
74	phys_addr_t this_start, this_end;
75
76	for_each_free_mem_range(i, MAX_NUMNODES, &this_start, &this_end, NULL) {
77		this_start = clamp_t(phys_addr_t, this_start, start, end);
78		this_end = clamp_t(phys_addr_t, this_end, start, end);
79		if (this_start < this_end) {
80			printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
81			       (unsigned long long)this_start,
82			       (unsigned long long)this_end,
83			       (unsigned long long)cpu_to_be64(pattern));
84			memtest(pattern, this_start, this_end - this_start);
85		}
86	}
87}
88
89/* default is disabled */
90static int memtest_pattern __initdata;
91
92static int __init parse_memtest(char *arg)
93{
94	if (arg)
95		memtest_pattern = simple_strtoul(arg, NULL, 0);
96	else
97		memtest_pattern = ARRAY_SIZE(patterns);
98
99	return 0;
100}
101
102early_param("memtest", parse_memtest);
103
104void __init early_memtest(unsigned long start, unsigned long end)
105{
106	unsigned int i;
107	unsigned int idx = 0;
108
109	if (!memtest_pattern)
110		return;
111
112	printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
113	for (i = 0; i < memtest_pattern; i++) {
114		idx = i % ARRAY_SIZE(patterns);
115		do_one_pass(patterns[idx], start, end);
116	}
117
118	if (idx > 0) {
119		printk(KERN_INFO "early_memtest: wipe out "
120		       "test pattern from memory\n");
121		/* additional test with pattern 0 will do this */
122		do_one_pass(0, start, end);
123	}
124}
125