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1// SPDX-License-Identifier: GPL-2.02#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 for (p = start; p < end; p++)54 WRITE_ONCE(*p, pattern);55 56 for (p = start; p < end; p++, start_phys_aligned += incr) {57 if (READ_ONCE(*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 early_memtest_done = true;71}72 73static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)74{75 u64 i;76 phys_addr_t this_start, this_end;77 78 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start,79 &this_end, NULL) {80 this_start = clamp(this_start, start, end);81 this_end = clamp(this_end, start, end);82 if (this_start < this_end) {83 pr_info(" %pa - %pa pattern %016llx\n",84 &this_start, &this_end, cpu_to_be64(pattern));85 memtest(pattern, this_start, this_end - this_start);86 }87 }88}89 90/* default is disabled */91static unsigned int memtest_pattern __initdata;92 93static int __init parse_memtest(char *arg)94{95 int ret = 0;96 97 if (arg)98 ret = kstrtouint(arg, 0, &memtest_pattern);99 else100 memtest_pattern = ARRAY_SIZE(patterns);101 102 return ret;103}104 105early_param("memtest", parse_memtest);106 107void __init early_memtest(phys_addr_t start, phys_addr_t end)108{109 unsigned int i;110 unsigned int idx = 0;111 112 if (!memtest_pattern)113 return;114 115 pr_info("early_memtest: # of tests: %u\n", memtest_pattern);116 for (i = memtest_pattern-1; i < UINT_MAX; --i) {117 idx = i % ARRAY_SIZE(patterns);118 do_one_pass(patterns[idx], start, end);119 }120}121 122void memtest_report_meminfo(struct seq_file *m)123{124 unsigned long early_memtest_bad_size_kb;125 126 if (!IS_ENABLED(CONFIG_PROC_FS))127 return;128 129 if (!early_memtest_done)130 return;131 132 early_memtest_bad_size_kb = early_memtest_bad_size >> 10;133 if (early_memtest_bad_size && !early_memtest_bad_size_kb)134 early_memtest_bad_size_kb = 1;135 /* When 0 is reported, it means there actually was a successful test */136 seq_printf(m, "EarlyMemtestBad: %5lu kB\n", early_memtest_bad_size_kb);137}138