1#include <linux/kernel.h> 2#include <linux/errno.h> 3#include <linux/string.h> 4#include <linux/types.h> 5#include <linux/mm.h> 6#include <linux/smp.h> 7#include <linux/init.h> 8#include <linux/pfn.h> 9 10#include <asm/e820.h> 11 12static u64 patterns[] __initdata = { 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, u64 start_bad, u64 end_bad) 33{ 34 printk(KERN_INFO " %016llx bad mem addr %010llx - %010llx reserved\n", 35 (unsigned long long) pattern, 36 (unsigned long long) start_bad, 37 (unsigned long long) end_bad); 38 reserve_early(start_bad, end_bad, "BAD RAM"); 39} 40 41static void __init memtest(u64 pattern, u64 start_phys, u64 size) 42{ 43 u64 *p, *start, *end; 44 u64 start_bad, last_bad; 45 u64 start_phys_aligned; 46 const size_t incr = sizeof(pattern); 47 48 start_phys_aligned = ALIGN(start_phys, incr); 49 start = __va(start_phys_aligned); 50 end = start + (size - (start_phys_aligned - start_phys)) / incr; 51 start_bad = 0; 52 last_bad = 0; 53 54 for (p = start; p < end; p++) 55 *p = pattern; 56 57 for (p = start; p < end; p++, start_phys_aligned += incr) { 58 if (*p == pattern) 59 continue; 60 if (start_phys_aligned == last_bad + incr) { 61 last_bad += incr; 62 continue; 63 } 64 if (start_bad) 65 reserve_bad_mem(pattern, start_bad, last_bad + incr); 66 start_bad = last_bad = start_phys_aligned; 67 } 68 if (start_bad) 69 reserve_bad_mem(pattern, start_bad, last_bad + incr); 70} 71 72static void __init do_one_pass(u64 pattern, u64 start, u64 end) 73{ 74 u64 size = 0; 75 76 while (start < end) { 77 start = find_e820_area_size(start, &size, 1); 78 79 /* done ? */ 80 if (start >= end) 81 break; 82 if (start + size > end) 83 size = end - start; 84 85 printk(KERN_INFO " %010llx - %010llx pattern %016llx\n", 86 (unsigned long long) start, 87 (unsigned long long) start + size, 88 (unsigned long long) cpu_to_be64(pattern)); 89 memtest(pattern, start, size); 90 91 start += size; 92 } 93} 94 95/* default is disabled */ 96static int memtest_pattern __initdata; 97 98static int __init parse_memtest(char *arg) 99{ 100 if (arg) 101 memtest_pattern = simple_strtoul(arg, NULL, 0); 102 else 103 memtest_pattern = ARRAY_SIZE(patterns); 104 105 return 0; 106} 107 108early_param("memtest", parse_memtest); 109 110void __init early_memtest(unsigned long start, unsigned long end) 111{ 112 unsigned int i; 113 unsigned int idx = 0; 114 115 if (!memtest_pattern) 116 return; 117 118 printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern); 119 for (i = 0; i < memtest_pattern; i++) { 120 idx = i % ARRAY_SIZE(patterns); 121 do_one_pass(patterns[idx], start, end); 122 } 123 124 if (idx > 0) { 125 printk(KERN_INFO "early_memtest: wipe out " 126 "test pattern from memory\n"); 127 /* additional test with pattern 0 will do this */ 128 do_one_pass(0, start, end); 129 } 130} 131