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x86: early memtest to find bad ram

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do simple memtest after init_memory_mapping

use find_e820_area_size to find all ram range that is not reserved.

and do some simple bits test to find some bad ram.

if find some bad ram, use reserve_early to exclude that range.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Yinghai Lu
2008-03-20 23:58:33 -07:00
committed by Ingo Molnar
parent a5ae1c372d
commit 272b9cad6e
3 changed files with 177 additions and 2 deletions
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106
arch/x86/mm/init_64.c
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@@ -427,6 +427,106 @@ static void __init init_gbpages(void)
direct_gbpages = 0;
}
static void __init memtest(unsigned long start_phys, unsigned long size, unsigned pattern)
{
unsigned long i;
unsigned long *start;
unsigned long start_bad;
unsigned long last_bad;
unsigned long val;
unsigned long start_phys_aligned;
unsigned long count;
unsigned long incr;
switch (pattern) {
case 0:
val = 0UL;
break;
case 1:
val = -1UL;
break;
case 2:
val = 0x5555555555555555UL;
break;
case 3:
val = 0xaaaaaaaaaaaaaaaaUL;
break;
default:
return;
}
incr = sizeof(unsigned long);
start_phys_aligned = ALIGN(start_phys, incr);
count = (size - (start_phys_aligned - start_phys))/incr;
start = __va(start_phys_aligned);
start_bad = 0;
last_bad = 0;
for (i = 0; i < count; i++)
start[i] = val;
for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
if (*start != val) {
if (start_phys_aligned == last_bad + incr) {
last_bad += incr;
} else {
if (start_bad) {
printk(KERN_INFO " %016lxx bad mem addr %016lx - %016lx reserved\n",
val, start_bad, last_bad + incr);
reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
}
start_bad = last_bad = start_phys_aligned;
}
}
}
if (start_bad) {
printk(KERN_INFO " %016lx bad mem addr %016lx - %016lx reserved\n",
val, start_bad, last_bad + incr);
reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
}
}
static int __initdata memtest_pattern;
static int __init parse_memtest(char *arg)
{
if (arg)
memtest_pattern = simple_strtoul(arg, NULL, 0) + 1;
return 0;
}
early_param("memtest", parse_memtest);
static void __init early_memtest(unsigned long start, unsigned long end)
{
unsigned long t_start, t_size;
unsigned pattern;
if (memtest_pattern)
printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
for (pattern = 0; pattern < memtest_pattern; pattern++) {
t_start = start;
t_size = 0;
while (t_start < end) {
t_start = find_e820_area_size(t_start, &t_size, 1);
/* done ? */
if (t_start >= end)
break;
if (t_start + t_size > end)
t_size = end - t_start;
printk(KERN_CONT "\n %016lx - %016lx pattern %d",
t_start, t_start + t_size, pattern);
memtest(t_start, t_size, pattern);
t_start += t_size;
}
}
if (memtest_pattern)
printk(KERN_CONT "\n");
}
/*
* Setup the direct mapping of the physical memory at PAGE_OFFSET.
* This runs before bootmem is initialized and gets pages directly from
@@ -435,8 +535,9 @@ static void __init init_gbpages(void)
void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
{
unsigned long next;
unsigned long start_phys = start, end_phys = end;
pr_debug("init_memory_mapping\n");
printk(KERN_INFO "init_memory_mapping\n");
/*
* Find space for the kernel direct mapping tables.
@@ -479,6 +580,9 @@ void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
if (!after_bootmem)
reserve_early(table_start << PAGE_SHIFT,
table_end << PAGE_SHIFT, "PGTABLE");
if (!after_bootmem)
early_memtest(start_phys, end_phys);
}
#ifndef CONFIG_NUMA