projects/linux·blob master · refs

139 lines · 3.5 KiB

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#include <linux/seq_file.h>
7
8static bool early_memtest_done;
9static phys_addr_t early_memtest_bad_size;
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 pr_info(" %016llx bad mem addr %pa - %pa reserved\n",
35 cpu_to_be64(pattern), &start_bad, &end_bad);
36 memblock_reserve(start_bad, end_bad - start_bad);
37 early_memtest_bad_size += (end_bad - start_bad);
38}
39
40static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size)
41{
42 u64 *p, *start, *end;
43 phys_addr_t start_bad, last_bad;
44 phys_addr_t 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 VM_WARN_ON_ONCE(size < start_phys_aligned - start_phys);
54
55 for (p = start; p < end; p++)
56 WRITE_ONCE(*p, pattern);
57
58 for (p = start; p < end; p++, start_phys_aligned += incr) {
59 if (READ_ONCE(*p) == pattern)
60 continue;
61 if (start_phys_aligned == last_bad + incr) {
62 last_bad += incr;
63 continue;
64 }
65 if (start_bad)
66 reserve_bad_mem(pattern, start_bad, last_bad + incr);
67 start_bad = last_bad = start_phys_aligned;
68 }
69 if (start_bad)
70 reserve_bad_mem(pattern, start_bad, last_bad + incr);
71
72 early_memtest_done = true;
73}
74
75static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
76{
77 u64 i;
78 phys_addr_t this_start, this_end;
79
80 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start,
81 &this_end, NULL) {
82 this_start = clamp(this_start, start, end);
83 this_end = clamp(this_end, start, end);
84 if (this_start < this_end) {
85 pr_info(" %pa - %pa pattern %016llx\n",
86 &this_start, &this_end, cpu_to_be64(pattern));
87 memtest(pattern, this_start, this_end - this_start);
88 }
89 }
90}
91
92/* default is disabled */
93static unsigned int memtest_pattern __initdata;
94
95static int __init parse_memtest(char *arg)
96{
97 int ret = 0;
98
99 if (arg)
100 ret = kstrtouint(arg, 0, &memtest_pattern);
101 else
102 memtest_pattern = ARRAY_SIZE(patterns);
103
104 return ret;
105}
106
107early_param("memtest", parse_memtest);
108
109void __init early_memtest(phys_addr_t start, phys_addr_t end)
110{
111 unsigned int i;
112 unsigned int idx = 0;
113
114 if (!memtest_pattern)
115 return;
116
117 pr_info("early_memtest: # of tests: %u\n", memtest_pattern);
118 for (i = memtest_pattern-1; i < UINT_MAX; --i) {
119 idx = i % ARRAY_SIZE(patterns);
120 do_one_pass(patterns[idx], start, end);
121 }
122}
123
124void memtest_report_meminfo(struct seq_file *m)
125{
126 unsigned long early_memtest_bad_size_kb;
127
128 if (!IS_ENABLED(CONFIG_PROC_FS))
129 return;
130
131 if (!early_memtest_done)
132 return;
133
134 early_memtest_bad_size_kb = early_memtest_bad_size >> 10;
135 if (early_memtest_bad_size && !early_memtest_bad_size_kb)
136 early_memtest_bad_size_kb = 1;
137 /* When 0 is reported, it means there actually was a successful test */
138 seq_printf(m, "EarlyMemtestBad: %5lu kB\n", early_memtest_bad_size_kb);
139}