linux/arch/x86/mm/memtest.c

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#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/pfn.h>
#include <asm/e820.h>
static u64 patterns[] __initdata = {
0,
0xffffffffffffffffULL,
0x5555555555555555ULL,
0xaaaaaaaaaaaaaaaaULL,
0x1111111111111111ULL,
0x2222222222222222ULL,
0x4444444444444444ULL,
0x8888888888888888ULL,
0x3333333333333333ULL,
0x6666666666666666ULL,
0x9999999999999999ULL,
0xccccccccccccccccULL,
0x7777777777777777ULL,
0xbbbbbbbbbbbbbbbbULL,
0xddddddddddddddddULL,
0xeeeeeeeeeeeeeeeeULL,
0x7a6c7258554e494cULL, /* yeah ;-) */
};
static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
{
printk(KERN_INFO " %016llx bad mem addr %010llx - %010llx reserved\n",
(unsigned long long) pattern,
(unsigned long long) start_bad,
(unsigned long long) end_bad);
reserve_early(start_bad, end_bad, "BAD RAM");
}
static void __init memtest(u64 pattern, u64 start_phys, u64 size)
{
u64 *p, *start, *end;
u64 start_bad, last_bad;
u64 start_phys_aligned;
const size_t incr = sizeof(pattern);
start_phys_aligned = ALIGN(start_phys, incr);
start = __va(start_phys_aligned);
end = start + (size - (start_phys_aligned - start_phys)) / incr;
start_bad = 0;
last_bad = 0;
for (p = start; p < end; p++)
*p = pattern;
for (p = start; p < end; p++, start_phys_aligned += incr) {
if (*p == pattern)
continue;
if (start_phys_aligned == last_bad + incr) {
last_bad += incr;
continue;
}
if (start_bad)
reserve_bad_mem(pattern, start_bad, last_bad + incr);
start_bad = last_bad = start_phys_aligned;
}
if (start_bad)
reserve_bad_mem(pattern, start_bad, last_bad + incr);
}
static void __init do_one_pass(u64 pattern, u64 start, u64 end)
{
u64 size = 0;
while (start < end) {
start = find_e820_area_size(start, &size, 1);
/* done ? */
if (start >= end)
break;
if (start + size > end)
size = end - start;
printk(KERN_INFO " %010llx - %010llx pattern %016llx\n",
(unsigned long long) start,
(unsigned long long) start + size,
(unsigned long long) cpu_to_be64(pattern));
memtest(pattern, start, size);
start += size;
}
}
/* default is disabled */
static int memtest_pattern __initdata;
static int __init parse_memtest(char *arg)
{
if (arg)
memtest_pattern = simple_strtoul(arg, NULL, 0);
else
memtest_pattern = ARRAY_SIZE(patterns);
return 0;
}
early_param("memtest", parse_memtest);
void __init early_memtest(unsigned long start, unsigned long end)
{
unsigned int i;
unsigned int idx = 0;
if (!memtest_pattern)
return;
printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
for (i = 0; i < memtest_pattern; i++) {
idx = i % ARRAY_SIZE(patterns);
do_one_pass(patterns[idx], start, end);
}
if (idx > 0) {
printk(KERN_INFO "early_memtest: wipe out "
"test pattern from memory\n");
/* additional test with pattern 0 will do this */
do_one_pass(0, start, end);
}
}