linux/arch/x86/kernel/check.c
Yinghai Lu 72d7c3b33c x86: Use memblock to replace early_res
1. replace find_e820_area with memblock_find_in_range
2. replace reserve_early with memblock_x86_reserve_range
3. replace free_early with memblock_x86_free_range.
4. NO_BOOTMEM will switch to use memblock too.
5. use _e820, _early wrap in the patch, in following patch, will
   replace them all
6. because memblock_x86_free_range support partial free, we can remove some special care
7. Need to make sure that memblock_find_in_range() is called after memblock_x86_fill()
   so adjust some calling later in setup.c::setup_arch()
   -- corruption_check and mptable_update

-v2: Move reserve_brk() early
    Before fill_memblock_area, to avoid overlap between brk and memblock_find_in_range()
    that could happen We have more then 128 RAM entry in E820 tables, and
    memblock_x86_fill() could use memblock_find_in_range() to find a new place for
    memblock.memory.region array.
    and We don't need to use extend_brk() after fill_memblock_area()
    So move reserve_brk() early before fill_memblock_area().
-v3: Move find_smp_config early
    To make sure memblock_find_in_range not find wrong place, if BIOS doesn't put mptable
    in right place.
-v4: Treat RESERVED_KERN as RAM in memblock.memory. and they are already in
    memblock.reserved already..
    use __NOT_KEEP_MEMBLOCK to make sure memblock related code could be freed later.
-v5: Generic version __memblock_find_in_range() is going from high to low, and for 32bit
    active_region for 32bit does include high pages
    need to replace the limit with memblock.default_alloc_limit, aka get_max_mapped()
-v6: Use current_limit instead
-v7: check with MEMBLOCK_ERROR instead of -1ULL or -1L
-v8: Set memblock_can_resize early to handle EFI with more RAM entries
-v9: update after kmemleak changes in mainline

Suggested-by: David S. Miller <davem@davemloft.net>
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-08-27 11:12:29 -07:00

164 lines
3.8 KiB
C

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/workqueue.h>
#include <linux/memblock.h>
#include <asm/proto.h>
/*
* Some BIOSes seem to corrupt the low 64k of memory during events
* like suspend/resume and unplugging an HDMI cable. Reserve all
* remaining free memory in that area and fill it with a distinct
* pattern.
*/
#define MAX_SCAN_AREAS 8
static int __read_mostly memory_corruption_check = -1;
static unsigned __read_mostly corruption_check_size = 64*1024;
static unsigned __read_mostly corruption_check_period = 60; /* seconds */
static struct scan_area {
u64 addr;
u64 size;
} scan_areas[MAX_SCAN_AREAS];
static int num_scan_areas;
static __init int set_corruption_check(char *arg)
{
char *end;
memory_corruption_check = simple_strtol(arg, &end, 10);
return (*end == 0) ? 0 : -EINVAL;
}
early_param("memory_corruption_check", set_corruption_check);
static __init int set_corruption_check_period(char *arg)
{
char *end;
corruption_check_period = simple_strtoul(arg, &end, 10);
return (*end == 0) ? 0 : -EINVAL;
}
early_param("memory_corruption_check_period", set_corruption_check_period);
static __init int set_corruption_check_size(char *arg)
{
char *end;
unsigned size;
size = memparse(arg, &end);
if (*end == '\0')
corruption_check_size = size;
return (size == corruption_check_size) ? 0 : -EINVAL;
}
early_param("memory_corruption_check_size", set_corruption_check_size);
void __init setup_bios_corruption_check(void)
{
u64 addr = PAGE_SIZE; /* assume first page is reserved anyway */
if (memory_corruption_check == -1) {
memory_corruption_check =
#ifdef CONFIG_X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1
#else
0
#endif
;
}
if (corruption_check_size == 0)
memory_corruption_check = 0;
if (!memory_corruption_check)
return;
corruption_check_size = round_up(corruption_check_size, PAGE_SIZE);
while (addr < corruption_check_size && num_scan_areas < MAX_SCAN_AREAS) {
u64 size;
addr = memblock_x86_find_in_range_size(addr, &size, PAGE_SIZE);
if (addr == MEMBLOCK_ERROR)
break;
if (addr >= corruption_check_size)
break;
if ((addr + size) > corruption_check_size)
size = corruption_check_size - addr;
memblock_x86_reserve_range(addr, addr + size, "SCAN RAM");
scan_areas[num_scan_areas].addr = addr;
scan_areas[num_scan_areas].size = size;
num_scan_areas++;
/* Assume we've already mapped this early memory */
memset(__va(addr), 0, size);
addr += size;
}
printk(KERN_INFO "Scanning %d areas for low memory corruption\n",
num_scan_areas);
}
void check_for_bios_corruption(void)
{
int i;
int corruption = 0;
if (!memory_corruption_check)
return;
for (i = 0; i < num_scan_areas; i++) {
unsigned long *addr = __va(scan_areas[i].addr);
unsigned long size = scan_areas[i].size;
for (; size; addr++, size -= sizeof(unsigned long)) {
if (!*addr)
continue;
printk(KERN_ERR "Corrupted low memory at %p (%lx phys) = %08lx\n",
addr, __pa(addr), *addr);
corruption = 1;
*addr = 0;
}
}
WARN_ONCE(corruption, KERN_ERR "Memory corruption detected in low memory\n");
}
static void check_corruption(struct work_struct *dummy);
static DECLARE_DELAYED_WORK(bios_check_work, check_corruption);
static void check_corruption(struct work_struct *dummy)
{
check_for_bios_corruption();
schedule_delayed_work(&bios_check_work,
round_jiffies_relative(corruption_check_period*HZ));
}
static int start_periodic_check_for_corruption(void)
{
if (!memory_corruption_check || corruption_check_period == 0)
return 0;
printk(KERN_INFO "Scanning for low memory corruption every %d seconds\n",
corruption_check_period);
/* First time we run the checks right away */
schedule_delayed_work(&bios_check_work, 0);
return 0;
}
module_init(start_periodic_check_for_corruption);