[PATCH 5/6] common: add mem_test routine

Marc Kleine-Budde mkl at pengutronix.de
Thu Feb 7 05:52:47 EST 2013


On 02/07/2013 11:44 AM, Alexander Aring wrote:
> Useful to detect timing problems if someone porting a new
> device to barebox.
> 
> This test includes a data bus test, address bus test and
> integrity check of memory.
> 
> Allocated barebox regions between start and end will skip
> automatically.

Some nitpicking inline.

Is there a nice alternative to usage of the vu_long type?
> 
> Signed-off-by: Alexander Aring <alex.aring at gmail.com>
> ---
>  common/Kconfig        |   7 +
>  common/Makefile       |   1 +
>  common/memory_test.c  | 399 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/memory_test.h |  13 ++
>  4 files changed, 420 insertions(+)
>  create mode 100644 common/memory_test.c
>  create mode 100644 include/memory_test.h
> 
> diff --git a/common/Kconfig b/common/Kconfig
> index 3f6c11e..c6988df 100644
> --- a/common/Kconfig
> +++ b/common/Kconfig
> @@ -100,6 +100,13 @@ config MEMINFO
>  	bool "display memory info"
>  	default y
>  
> +config MEMTEST
> +	bool "Offers routines for memory test"
> +	help
> +	  Offers memtest routines in common/memory_test.c
> +	  This is helpful for porting devices to detect
> +	  memory timing problems.
> +
>  config ENVIRONMENT_VARIABLES
>  	bool "environment variables support"
>  
> diff --git a/common/Makefile b/common/Makefile
> index 7206eed..684953c 100644
> --- a/common/Makefile
> +++ b/common/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_MALLOC_DLMALLOC) += dlmalloc.o
>  obj-$(CONFIG_MALLOC_TLSF) += tlsf_malloc.o
>  obj-$(CONFIG_MALLOC_TLSF) += tlsf.o
>  obj-$(CONFIG_MALLOC_DUMMY) += dummy_malloc.o
> +obj-$(CONFIG_MEMTEST) += memory_test.o
>  obj-y += clock.o
>  obj-$(CONFIG_BANNER) += version.o
>  obj-$(CONFIG_MEMINFO) += meminfo.o
> diff --git a/common/memory_test.c b/common/memory_test.c
> new file mode 100644
> index 0000000..80b4ff4
> --- /dev/null
> +++ b/common/memory_test.c
> @@ -0,0 +1,399 @@
> +/*
> + * memory_test.c
> + *
> + * Copyright (c) 2013 Alexander Aring <aar at pengutronix.de>, Pengutronix
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <memory_test.h>
> +
> +static const vu_long bitpattern[] = {
> +	0x00000001,	/* single bit */
> +	0x00000003,	/* two adjacent bits */
> +	0x00000007,	/* three adjacent bits */
> +	0x0000000F,	/* four adjacent bits */
> +	0x00000005,	/* two non-adjacent bits */
> +	0x00000015,	/* three non-adjacent bits */
> +	0x00000055,	/* four non-adjacent bits */
> +	0xAAAAAAAA,	/* alternating 1/0 */
> +};
> +
> +/*
> + * Perform a memory test. The complete test
> + * loops until interrupted by ctrl-c.
> + *
> + * Highly recommended to test with disabled and
> + * enabled cache.
> + *
> + * start: start address
> + * end: end address
> + * bus_only: skip integrity check
> + */
> +int mem_test(vu_long _start, vu_long _end,
> +		int bus_only)
> +{
> +	vu_long *start;
> +	vu_long *dummy;
> +
> +	vu_long val;
> +	vu_long readback;
> +	vu_long offset;
> +	vu_long offset2;
> +	vu_long pattern;
> +	vu_long temp;
> +	vu_long anti_pattern;
> +	vu_long num_words;
> +
> +	int i;
> +	int ret;
> +
> +	if (!IS_ALIGNED(_start, sizeof(vu_long)))
> +		_start = ALIGN(_start, sizeof(vu_long));
> +	/*
> +	 * check if end is a multiple of vu_long.
> +	 * need to add 1 because ALIGNED works with
> +	 * inclusive byte at end address.
> +	 *
> +	 * Also check on _end == 0. Otherwise we get a
> +	 * underflow.
> +	 */
> +	if (!IS_ALIGNED(_end + 1, sizeof(vu_long)) && _end)
> +		_end = ALIGN_DOWN(_end, sizeof(vu_long)) - 1;
> +
> +	/*
> +	 * TODO
> +	 * recheck after align. That's not a quite
> +	 * solution now because we already done this
> +	 * in memtest command.
> +	 */
> +	if (_end <= _start)
> +		return -1;
> +
> +	start = (vu_long *)_start;
> +	/*
> +	 * Point the dummy to start[1]
> +	 */
> +	dummy = start+1;
> +	num_words = (_end - _start + 1)/sizeof(vu_long);
> +
> +	/*
> +	 * Checking if start and dummy address are in one
> +	 * of barebox regions. Otherwise next data line testing
> +	 * will maybe fail.
> +	 */
> +	ret = address_in_sdram_regions((vu_long)start);
> +	ret |= address_in_sdram_regions((vu_long)dummy);
> +	if (ret) {
> +		printf("WARNING (data line): "
> +				"address 0x%08lx is in sdram regions.\n"
> +				"Try another start address to fix this issue.\n",
> +				(vu_long)start);
> +		return -1;
> +	}
> +
> +	printf("Starting data line test.\n");
> +
> +	/*
> +	 * Data line test: write a pattern to the first
> +	 * location, write the 1's complement to a 'parking'
> +	 * address (changes the state of the data bus so a
> +	 * floating bus doen't give a false OK), and then
> +	 * read the value back. Note that we read it back
> +	 * into a variable because the next time we read it,
> +	 * it might be right (been there, tough to explain to
> +	 * the quality guys why it prints a failure when the
> +	 * "is" and "should be" are obviously the same in the
> +	 * error message).
> +	 *
> +	 * Rather than exhaustively testing, we test some
> +	 * patterns by shifting '1' bits through a field of
> +	 * '0's and '0' bits through a field of '1's (i.e.
> +	 * pattern and ~pattern).
> +	 */
> +	for (i = 0; i < sizeof(bitpattern)/
> +			sizeof(bitpattern[0]); i++) {

ARRAY_SIZE(bitpattern)

> +		val = bitpattern[i];
> +
> +		for (; val != 0; val <<= 1) {
> +			*start = val;
> +			/* clear the test data off of the bus */
> +			*dummy = ~val;
> +			readback = *start;
> +
> +			if (readback != val) {
> +				printf("FAILURE (data line): "
> +					"expected 0x%08lx, actual 0x%08lx at address 0x%08lx.\n",
> +					val, readback, (vu_long)start);
> +				return -1;
> +			}
> +
> +			*start = ~val;
> +			*dummy = val;
> +			readback = *start;
> +			if (readback != ~val) {
> +				printf("FAILURE (data line): "
> +					"Is 0x%08lx, should be 0x%08lx at address 0x%08lx.\n",
> +					readback,
> +					~val, (vu_long)start);
> +				return -1;
> +			}
> +		}
> +	}
> +
> +
> +	/*
> +	 * Based on code whose Original Author and Copyright
> +	 * information follows: Copyright (c) 1998 by Michael
> +	 * Barr. This software is placed into the public
> +	 * domain and may be used for any purpose. However,
> +	 * this notice must not be changed or removed and no
> +	 * warranty is either expressed or implied by its
> +	 * publication or distribution.
> +	 */
> +
> +	/*
> +	 * Address line test
> +	 *
> +	 * Description: Test the address bus wiring in a
> +	 *              memory region by performing a walking
> +	 *              1's test on the relevant bits of the
> +	 *              address and checking for aliasing.
> +	 *              This test will find single-bit
> +	 *              address failures such as stuck -high,
> +	 *              stuck-low, and shorted pins. The base
> +	 *              address and size of the region are
> +	 *              selected by the caller.
> +	 *
> +	 * Notes:	For best results, the selected base
> +	 *              address should have enough LSB 0's to
> +	 *              guarantee single address bit changes.
> +	 *              For example, to test a 64-Kbyte
> +	 *              region, select a base address on a
> +	 *              64-Kbyte boundary. Also, select the
> +	 *              region size as a power-of-two if at
> +	 *              all possible.
> +	 *
> +	 * ## NOTE ##	Be sure to specify start and end
> +	 *              addresses such that num_words has
> +	 *              lots of bits set. For example an
> +	 *              address range of 01000000 02000000 is
> +	 *              bad while a range of 01000000
> +	 *              01ffffff is perfect.
> +	 */
> +
> +	pattern = 0xAAAAAAAA;
> +	anti_pattern = 0x55555555;
> +
> +	/*
> +	 * Write the default pattern at each of the
> +	 * power-of-two offsets.
> +	 */
> +	for (offset = 1; offset <= num_words; offset <<= 1) {
> +		ret = address_in_sdram_regions((vu_long)&start[offset]);
> +		if (ret) {
> +			printf("WARNING (stuck high): "
> +					"address 0x%08lx is in barebox regions.\n",
> +					(vu_long)&start[offset]);
> +			continue;
> +		}
> +
> +		start[offset] = pattern;
> +	}
> +
> +	printf("Check for address bits stuck high.\n");
> +
> +	/*
> +	 * Check for address bits stuck high.
> +	 */
> +	for (offset = 1; offset <= num_words; offset <<= 1) {
> +		ret = address_in_sdram_regions((vu_long)&start[offset]);
> +		if (ret)
> +			continue;
> +
> +		temp = start[offset];
> +		if (temp != pattern) {
> +			printf("FAILURE: Address bit "
> +					"stuck high @ 0x%08lx:"
> +					" expected 0x%08lx, actual 0x%08lx.\n",
> +					(vu_long)&start[offset],
> +					pattern, temp);
> +			return -1;
> +		}
> +	}
> +
> +	printf("Check for address bits stuck "
> +			"low or shorted.\n");
> +
> +	/*
> +	 * Check for address bits stuck low or shorted.
> +	 */
> +	for (offset2 = 1; offset2 <= num_words; offset2 <<= 1) {
> +		ret = address_in_sdram_regions(
> +				(vu_long)&start[offset2]);
> +		if (ret) {
> +			printf("WARNING (low high): "
> +					"address 0x%08lx is in barebox regions.\n",
> +					(vu_long)&start[offset2]);
> +			continue;
> +		}
> +
> +		start[offset2] = anti_pattern;
> +
> +		for (offset = 1; offset <= num_words; offset <<= 1) {
> +			ret = address_in_sdram_regions(
> +					(vu_long)&start[offset]);
> +			if (ret)
> +				continue;
> +
> +			temp = start[offset];
> +
> +			/*
> +			 * That's some complicated for loop with
> +			 * condition offset != test_offset inside. I
> +			 * think this is necessary to put some another
> +			 * address on the bus.
> +			 *
> +			 * TODO
> +			 * check if loop is necessary.
> +			 */
> +			if ((temp != pattern) &&
> +					(offset != offset2)) {
> +				printf("FAILURE: Address bit stuck"
> +						" low or shorted @"
> +						" 0x%08lx: expected 0x%08lx, actual 0x%08lx.\n",
> +						(vu_long)&start[offset],
> +						pattern, temp);
> +				return -1;
> +			}
> +		}
> +		start[offset2] = pattern;
> +	}
> +
> +	/*
> +	 * We tested only the bus if != 0
> +	 * leaving here
> +	 */
> +	if (bus_only)
> +		return 0;
> +
> +	printf("Starting integrity check of physicaly ram.\n"
> +			"Filling ram with patterns...\n");
> +
> +	/*
> +	 * Description: Test the integrity of a physical
> +	 *		memory device by performing an
> +	 *		increment/decrement test over the
> +	 *		entire region. In the process every
> +	 *		storage bit in the device is tested
> +	 *		as a zero and a one. The base address
> +	 *		and the size of the region are
> +	 *		selected by the caller.
> +	 */
> +
> +	/*
> +	 * Fill memory with a known pattern.
> +	 */
> +	init_progression_bar(num_words);
> +	for (offset = 0; offset < num_words; offset++) {
> +		if (!(offset & 0xfff)) {
> +			if (ctrlc())
> +				return -EINTR;
> +			show_progress(offset);
> +		}
> +
> +		ret = address_in_sdram_regions((vu_long)&start[offset]);
> +		if (ret)
> +			continue;
> +
> +		start[offset] = offset + 1;
> +	}
> +
> +	show_progress(offset);
> +
> +	printf("\nCompare written patterns...\n");
> +
> +	/*
> +	 * Check each location and invert it for the second pass.
> +	 */
> +	init_progression_bar(num_words - 1);
> +	for (offset = 0; offset < num_words; offset++) {
> +		if (!(offset & 0xfff)) {
> +			if (ctrlc())
> +				return -EINTR;
> +			show_progress(offset);
> +		}
> +
> +		ret = address_in_sdram_regions((vu_long)&start[offset]);
> +		if (ret)
> +			continue;
> +
> +		temp = start[offset];
> +		if (temp != (offset + 1)) {
> +			printf("\nFAILURE (read/write) @ 0x%08lx:"
> +					" expected 0x%08lx, actual 0x%08lx.\n",
> +					(vu_long)&start[offset],
> +					(offset + 1), temp);
> +			return -1;
> +		}
> +
> +		anti_pattern = ~(offset + 1);
> +		start[offset] = anti_pattern;
> +	}
> +
> +	show_progress(offset);
> +
> +	printf("\nFilling ram with inverted pattern and compare it...\n");
> +
> +	/*
> +	 * Check each location for the inverted pattern and zero it.
> +	 */
> +	init_progression_bar(num_words - 1);
> +	for (offset = 0; offset < num_words; offset++) {
> +		if (!(offset & 0xfff)) {
> +			if (ctrlc())
> +				return -EINTR;
> +			show_progress(offset);
> +		}
> +
> +		ret = address_in_sdram_regions((vu_long)&start[offset]);
> +		/*
> +		 * Step over barebox mem usage
> +		 */
> +		if (ret)
> +			continue;
> +
> +		anti_pattern = ~(offset + 1);
> +		temp = start[offset];
> +
> +		if (temp != anti_pattern) {
> +			printf("\nFAILURE (read/write): @ 0x%08lx:"
> +					" expected 0x%08lx, actual 0x%08lx.\n",
> +					(vu_long)&start[offset],
> +					anti_pattern, temp);
> +			return -1;

what about returning an errno?

> +		}
> +
> +		start[offset] = 0;
> +	}
> +
> +	show_progress(offset);
> +
> +	/*
> +	 * end of progressbar
> +	 */
> +	printf("\n");
> +
> +	return 0;
> +}
> diff --git a/include/memory_test.h b/include/memory_test.h
> new file mode 100644
> index 0000000..6959dc6
> --- /dev/null
> +++ b/include/memory_test.h
> @@ -0,0 +1,13 @@
> +
> +#ifndef __MEMORY_TEST_H
> +#define __MEMORY_TEST_H
> +
> +#include <progress.h>
> +#include <common.h>
> +#include <memory.h>
> +#include <types.h>
> +
> +int mem_test(vu_long _start, vu_long _end,
> +		int bus_only);
> +
> +#endif
> 

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

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