1// SPDX-License-Identifier: GPL-2.0
2#include <linux/kernel.h>
3#include <linux/types.h>
4#include <linux/init.h>
5#include <linux/memblock.h>
6
7static u64 patterns[] __initdata = {
8 /* The first entry has to be 0 to leave memtest with zeroed memory */
9 0,
10 0xffffffffffffffffULL,
11 0x5555555555555555ULL,
12 0xaaaaaaaaaaaaaaaaULL,
13 0x1111111111111111ULL,
14 0x2222222222222222ULL,
15 0x4444444444444444ULL,
16 0x8888888888888888ULL,
17 0x3333333333333333ULL,
18 0x6666666666666666ULL,
19 0x9999999999999999ULL,
20 0xccccccccccccccccULL,
21 0x7777777777777777ULL,
22 0xbbbbbbbbbbbbbbbbULL,
23 0xddddddddddddddddULL,
24 0xeeeeeeeeeeeeeeeeULL,
25 0x7a6c7258554e494cULL, /* yeah ;-) */
26};
27
28static void __init reserve_bad_mem(u64 pattern, phys_addr_t start_bad, phys_addr_t end_bad)
29{
30 pr_info(" %016llx bad mem addr %pa - %pa reserved\n",
31 cpu_to_be64(pattern), &start_bad, &end_bad);
32 memblock_reserve(start_bad, end_bad - start_bad);
33}
34
35static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size)
36{
37 u64 *p, *start, *end;
38 phys_addr_t start_bad, last_bad;
39 phys_addr_t start_phys_aligned;
40 const size_t incr = sizeof(pattern);
41
42 start_phys_aligned = ALIGN(start_phys, incr);
43 start = __va(start_phys_aligned);
44 end = start + (size - (start_phys_aligned - start_phys)) / incr;
45 start_bad = 0;
46 last_bad = 0;
47
48 for (p = start; p < end; p++)
49 *p = pattern;
50
51 for (p = start; p < end; p++, start_phys_aligned += incr) {
52 if (*p == pattern)
53 continue;
54 if (start_phys_aligned == last_bad + incr) {
55 last_bad += incr;
56 continue;
57 }
58 if (start_bad)
59 reserve_bad_mem(pattern, start_bad, last_bad + incr);
60 start_bad = last_bad = start_phys_aligned;
61 }
62 if (start_bad)
63 reserve_bad_mem(pattern, start_bad, last_bad + incr);
64}
65
66static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
67{
68 u64 i;
69 phys_addr_t this_start, this_end;
70
71 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start,
72 &this_end, NULL) {
73 this_start = clamp(this_start, start, end);
74 this_end = clamp(this_end, start, end);
75 if (this_start < this_end) {
76 pr_info(" %pa - %pa pattern %016llx\n",
77 &this_start, &this_end, cpu_to_be64(pattern));
78 memtest(pattern, this_start, this_end - this_start);
79 }
80 }
81}
82
83/* default is disabled */
84static unsigned int memtest_pattern __initdata;
85
86static int __init parse_memtest(char *arg)
87{
88 int ret = 0;
89
90 if (arg)
91 ret = kstrtouint(arg, 0, &memtest_pattern);
92 else
93 memtest_pattern = ARRAY_SIZE(patterns);
94
95 return ret;
96}
97
98early_param("memtest", parse_memtest);
99
100void __init early_memtest(phys_addr_t start, phys_addr_t end)
101{
102 unsigned int i;
103 unsigned int idx = 0;
104
105 if (!memtest_pattern)
106 return;
107
108 pr_info("early_memtest: # of tests: %u\n", memtest_pattern);
109 for (i = memtest_pattern-1; i < UINT_MAX; --i) {
110 idx = i % ARRAY_SIZE(patterns);
111 do_one_pass(patterns[idx], start, end);
112 }
113}
114