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 } 113