Commit 272b9cad authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86: early memtest to find bad ram 



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: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a5ae1c37

arch/x86/kernel/e820_64.c

+69 −1
Original line number Diff line number Diff line
@@ -114,6 +114,40 @@ again: 
	return changed;

}



/* Check for already reserved areas */

static inline int

bad_addr_size(unsigned long *addrp, unsigned long *sizep, unsigned long align)

{

	int i;

	unsigned long addr = *addrp, last;

	unsigned long size = *sizep;

	int changed = 0;

again:

	last = addr + size;

	for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {

		struct early_res *r = &early_res[i];

		if (last > r->start && addr < r->start) {

			size = r->start - addr;

			changed = 1;

			goto again;

		}

		if (last > r->end && addr < r->end) {

			addr = round_up(r->end, align);

			size = last - addr;

			changed = 1;

			goto again;

		}

		if (last <= r->end && addr >= r->start) {

			(*sizep)++;

			return 0;

		}

	}

	if (changed) {

		*addrp = addr;

		*sizep = size;

	}

	return changed;

}

/*

 * This function checks if any part of the range <start,end> is mapped

 * with type.
@@ -190,7 +224,7 @@ unsigned long __init find_e820_area(unsigned long start, unsigned long end, 
		ei_last = ei->addr + ei->size;

		if (addr < start)

			addr = round_up(start, align);

		if (addr > ei_last)

		if (addr >= ei_last)

			continue;

		while (bad_addr(&addr, size, align) && addr+size <= ei_last)

			;
@@ -204,6 +238,40 @@ unsigned long __init find_e820_area(unsigned long start, unsigned long end, 
	return -1UL;

}



/*

 * Find next free range after *start

 */

unsigned long __init find_e820_area_size(unsigned long start, unsigned long *sizep, unsigned long align)

{

	int i;



	for (i = 0; i < e820.nr_map; i++) {

		struct e820entry *ei = &e820.map[i];

		unsigned long addr, last;

		unsigned long ei_last;



		if (ei->type != E820_RAM)

			continue;

		addr = round_up(ei->addr, align);

		ei_last = ei->addr + ei->size;

//		printk(KERN_DEBUG "find_e820_area_size : e820 %d [%llx, %lx]\n", i, ei->addr, ei_last);

		if (addr < start)

			addr = round_up(start, align);

//		printk(KERN_DEBUG "find_e820_area_size : 0 [%lx, %lx]\n", addr, ei_last);

		if (addr >= ei_last)

			continue;

		*sizep = ei_last - addr;

		while (bad_addr_size(&addr, sizep, align) && addr+ *sizep <= ei_last)

			;

		last = addr + *sizep;

//		printk(KERN_DEBUG "find_e820_area_size : 1 [%lx, %lx]\n", addr, last);

		if (last > ei_last)

			continue;

		return addr;

	}

	return -1UL;



}

/*

 * Find the highest page frame number we have available

 */

arch/x86/mm/init_64.c

+105 −1
Original line number Diff line number Diff line
@@ -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

include/asm-x86/e820_64.h

+3 −0
Original line number Diff line number Diff line
@@ -16,6 +16,9 @@ 
#ifndef __ASSEMBLY__

extern unsigned long find_e820_area(unsigned long start, unsigned long end, 

				    unsigned long size, unsigned long align);

extern unsigned long find_e820_area_size(unsigned long start,

					 unsigned long *sizep,

					 unsigned long align);

extern void add_memory_region(unsigned long start, unsigned long size, 

			      int type);

extern void update_memory_range(u64 start, u64 size, unsigned old_type,

CRA Git | Maintained and supported by SUSTech CRA and CCSE