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/arch/x86/mm/memtest.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C | 130 lines | 107 code | 20 blank | 3 comment | 15 complexity | 6c6006f4fd79884a6a8e89b9defd7b82 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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}