[PATCH 4/5] common: add memtest.c with mem_test routine

[Alexander Aring <alex.aring@gmail.com>]

Add mem_test routine. 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.

This mem_test routine has as parameter start and end address of testing
space. The last parameter can skip the integrity check.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
---
 common/Makefile   |   1 +
 common/memtest.c  | 313 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/memtest.h |  14 +++
 3 files changed, 328 insertions(+)
 create mode 100644 common/memtest.c
 create mode 100644 include/memtest.h

diff --git a/common/Makefile b/common/Makefile
index 2f0bd34..d18b6c6 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -18,6 +18,7 @@ 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-$(CONFIG_CMD_MEMTEST) += memtest.o
 obj-y += clock.o
 obj-$(CONFIG_BANNER) += version.o
 obj-$(CONFIG_MEMINFO) += meminfo.o
diff --git a/common/memtest.c b/common/memtest.c
new file mode 100644
index 0000000..22178cf
--- /dev/null
+++ b/common/memtest.c
@@ -0,0 +1,313 @@
+/*
+ * memory_test.c
+ *
+ * Copyright (c) 2013 Alexander Aring <aar@pengutronix.de>, Pengutronix
+ *
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * 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 <progress.h>
+#include <common.h>
+#include <memory.h>
+#include <types.h>
+#include <sizes.h>
+#include <memtest.h>
+
+static const resource_size_t 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.
+ *
+ * Prameters:
+ * start: start address for memory test.
+ * end: end address of memory test.
+ * bus_only: skip integrity check and do only a address/data bus
+ *	     testing.
+ *
+ * Return value can be -EINVAL for invalid parameter or -EINTR
+ * if memory test was interrupted.
+ */
+int mem_test(resource_size_t _start,
+	       resource_size_t _end, int bus_only)
+{
+	volatile resource_size_t *start, *dummy, val, readback, offset,
+		offset2, pattern, temp, anti_pattern, num_words;
+	int i;
+
+	_start = ALIGN(_start, sizeof(resource_size_t));
+	_end = ALIGN_DOWN(_end, sizeof(resource_size_t)) - 1;
+
+	if (_end <= _start)
+		return -EINVAL;
+
+	start = (resource_size_t *)_start;
+	/*
+	 * Point the dummy to start[1]
+	 */
+	dummy = start + 1;
+	num_words = (_end - _start + 1)/sizeof(resource_size_t);
+
+	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 < ARRAY_SIZE(bitpattern)/
+			sizeof(resource_size_t); i++) {
+		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%08x, actual 0x%08x at address 0x%08x.\n",
+					val, readback, (resource_size_t)start);
+				return -EIO;
+			}
+
+			*start = ~val;
+			*dummy = val;
+			readback = *start;
+			if (readback != ~val) {
+				printf("FAILURE (data line): "
+					"Is 0x%08x, should be 0x%08x at address 0x%08x.\n",
+					readback,
+					~val, (resource_size_t)start);
+				return -EIO;
+			}
+		}
+	}
+
+
+	/*
+	 * 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)
+		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) {
+		temp = start[offset];
+		if (temp != pattern) {
+			printf("FAILURE: Address bit "
+					"stuck high @ 0x%08x:"
+					" expected 0x%08x, actual 0x%08x.\n",
+					(resource_size_t)&start[offset],
+					pattern, temp);
+			return -EIO;
+		}
+	}
+
+	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) {
+		start[offset2] = anti_pattern;
+
+		for (offset = 1; offset <= num_words; offset <<= 1) {
+			temp = start[offset];
+
+			if ((temp != pattern) &&
+					(offset != offset2)) {
+				printf("FAILURE: Address bit stuck"
+						" low or shorted @"
+						" 0x%08x: expected 0x%08x, actual 0x%08x.\n",
+						(resource_size_t)&start[offset],
+						pattern, temp);
+				return -EIO;
+			}
+		}
+		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++) {
+		/*
+		 * Every 4K we update the progressbar.
+		 */
+		if (!(offset & (SZ_4K - 1))) {
+			if (ctrlc())
+				return -EINTR;
+			show_progress(offset);
+		}
+
+		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 & (SZ_4K - 1))) {
+			if (ctrlc())
+				return -EINTR;
+			show_progress(offset);
+		}
+
+		temp = start[offset];
+		if (temp != (offset + 1)) {
+			printf("\nFAILURE (read/write) @ 0x%08x:"
+					" expected 0x%08x, actual 0x%08x.\n",
+					(resource_size_t)&start[offset],
+					(offset + 1), temp);
+			return -EIO;
+		}
+
+		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 & (SZ_4K - 1))) {
+			if (ctrlc())
+				return -EINTR;
+			show_progress(offset);
+		}
+
+		anti_pattern = ~(offset + 1);
+		temp = start[offset];
+
+		if (temp != anti_pattern) {
+			printf("\nFAILURE (read/write): @ 0x%08x:"
+					" expected 0x%08x, actual 0x%08x.\n",
+					(resource_size_t)&start[offset],
+					anti_pattern, temp);
+			return -EIO;
+		}
+
+		start[offset] = 0;
+	}
+	show_progress(offset);
+
+	/*
+	 * end of progressbar
+	 */
+	printf("\n");
+
+	return 0;
+}
diff --git a/include/memtest.h b/include/memtest.h
new file mode 100644
index 0000000..a337be8
--- /dev/null
+++ b/include/memtest.h
@@ -0,0 +1,14 @@
+#ifndef __MEMTEST_H
+#define __MEMTEST_H
+
+#include <linux/ioport.h>
+
+struct mem_test_resource {
+	struct resource *r;
+	struct list_head list;
+};
+
+int mem_test(resource_size_t _start,
+		resource_size_t _end, int bus_only);
+
+#endif /* __MEMTEST_H */
-- 
1.8.3


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