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, phys_addr_t start_bad, phys_addr_t 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, phys_addr_t start_phys, phys_addr_t size)
42{
43	u64 *p, *start, *end;
44	phys_addr_t start_bad, last_bad;
45	phys_addr_t 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, phys_addr_t start, phys_addr_t end)
73{
74	u64 i;
75	phys_addr_t this_start, this_end;
76
77	for_each_free_mem_range(i, NUMA_NO_NODE, &this_start, &this_end, NULL) {
78		this_start = clamp(this_start, start, end);
79		this_end = clamp(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(phys_addr_t start, phys_addr_t 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