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 7 static 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 28 static 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 35 static 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 66 static 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 */ 84 static unsigned int memtest_pattern __initdata; 85 86 static 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 98 early_param("memtest", parse_memtest); 99 100 void __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