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[mirror_ubuntu-bionic-kernel.git] / mm / memtest.c
1 #include <linux/kernel.h>
2 #include <linux/types.h>
3 #include <linux/init.h>
4 #include <linux/memblock.h>
5
6 static u64 patterns[] __initdata = {
7 /* The first entry has to be 0 to leave memtest with zeroed memory */
8 0,
9 0xffffffffffffffffULL,
10 0x5555555555555555ULL,
11 0xaaaaaaaaaaaaaaaaULL,
12 0x1111111111111111ULL,
13 0x2222222222222222ULL,
14 0x4444444444444444ULL,
15 0x8888888888888888ULL,
16 0x3333333333333333ULL,
17 0x6666666666666666ULL,
18 0x9999999999999999ULL,
19 0xccccccccccccccccULL,
20 0x7777777777777777ULL,
21 0xbbbbbbbbbbbbbbbbULL,
22 0xddddddddddddddddULL,
23 0xeeeeeeeeeeeeeeeeULL,
24 0x7a6c7258554e494cULL, /* yeah ;-) */
25 };
26
27 static void __init reserve_bad_mem(u64 pattern, phys_addr_t start_bad, phys_addr_t end_bad)
28 {
29 pr_info(" %016llx bad mem addr %pa - %pa reserved\n",
30 cpu_to_be64(pattern), &start_bad, &end_bad);
31 memblock_reserve(start_bad, end_bad - start_bad);
32 }
33
34 static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size)
35 {
36 u64 *p, *start, *end;
37 phys_addr_t start_bad, last_bad;
38 phys_addr_t start_phys_aligned;
39 const size_t incr = sizeof(pattern);
40
41 start_phys_aligned = ALIGN(start_phys, incr);
42 start = __va(start_phys_aligned);
43 end = start + (size - (start_phys_aligned - start_phys)) / incr;
44 start_bad = 0;
45 last_bad = 0;
46
47 for (p = start; p < end; p++)
48 *p = pattern;
49
50 for (p = start; p < end; p++, start_phys_aligned += incr) {
51 if (*p == pattern)
52 continue;
53 if (start_phys_aligned == last_bad + incr) {
54 last_bad += incr;
55 continue;
56 }
57 if (start_bad)
58 reserve_bad_mem(pattern, start_bad, last_bad + incr);
59 start_bad = last_bad = start_phys_aligned;
60 }
61 if (start_bad)
62 reserve_bad_mem(pattern, start_bad, last_bad + incr);
63 }
64
65 static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
66 {
67 u64 i;
68 phys_addr_t this_start, this_end;
69
70 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start,
71 &this_end, NULL) {
72 this_start = clamp(this_start, start, end);
73 this_end = clamp(this_end, start, end);
74 if (this_start < this_end) {
75 pr_info(" %pa - %pa pattern %016llx\n",
76 &this_start, &this_end, cpu_to_be64(pattern));
77 memtest(pattern, this_start, this_end - this_start);
78 }
79 }
80 }
81
82 /* default is disabled */
83 static unsigned int memtest_pattern __initdata;
84
85 static int __init parse_memtest(char *arg)
86 {
87 int ret = 0;
88
89 if (arg)
90 ret = kstrtouint(arg, 0, &memtest_pattern);
91 else
92 memtest_pattern = ARRAY_SIZE(patterns);
93
94 return ret;
95 }
96
97 early_param("memtest", parse_memtest);
98
99 void __init early_memtest(phys_addr_t start, phys_addr_t end)
100 {
101 unsigned int i;
102 unsigned int idx = 0;
103
104 if (!memtest_pattern)
105 return;
106
107 pr_info("early_memtest: # of tests: %u\n", memtest_pattern);
108 for (i = memtest_pattern-1; i < UINT_MAX; --i) {
109 idx = i % ARRAY_SIZE(patterns);
110 do_one_pass(patterns[idx], start, end);
111 }
112 }