/*
 * mtest - Perform a memory test
 *
 * (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 as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <command.h>
#include <types.h>

/*
 * Perform a memory test. A more complete alternative test can be
 * configured using CONFIG_CMD_MTEST_ALTERNATIVE. The complete test
 * loops until interrupted by ctrl-c or by a failure of one of the
 * sub-tests.
 */
#ifdef CONFIG_CMD_MTEST_ALTERNATIVE
static int mem_test(ulong _start, ulong _end, ulong pattern_unused)
{
	vu_long *start = (vu_long *)_start;
	vu_long *end   = (vu_long *)_end;
	vu_long *addr;
	ulong	val;
	ulong	readback;
	vu_long	addr_mask;
	vu_long	offset;
	vu_long	test_offset;
	vu_long	pattern;
	vu_long	temp;
	vu_long	anti_pattern;
	vu_long	num_words;
#ifdef CFG_MEMTEST_SCRATCH
	vu_long *dummy = (vu_long*)CFG_MEMTEST_SCRATCH;
#else
	vu_long *dummy = start;
#endif
	int	j;
	int iterations = 1;

	static const ulong 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 */
	};

	/* XXX: enforce alignment of start and end? */
	for (;;) {
		if (ctrlc()) {
			putchar ('\n');
			return 1;
		}

		printf("Iteration: %6d\r", iterations);
		iterations++;

		/*
		 * 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).
		 */
		addr = start;
		/* XXX */
		if (addr == dummy) ++addr;
		for (j = 0; j < sizeof(bitpattern)/sizeof(bitpattern[0]); j++) {
		    val = bitpattern[j];
		    for(; val != 0; val <<= 1) {
			*addr  = val;
			*dummy  = ~val; /* clear the test data off of the bus */
			readback = *addr;
			if(readback != val) {
			     printf ("FAILURE (data line): "
				"expected 0x%08lx, actual 0x%08lx at address 0x%p\n",
					  val, readback, addr);
			}
			*addr  = ~val;
			*dummy  = val;
			readback = *addr;
			if(readback != ~val) {
			    printf ("FAILURE (data line): "
				"Is 0x%08lx, should be 0x%08lx at address 0x%p\n",
					readback, ~val, addr);
			}
		    }
		}

		/*
		 * 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.
		 *
		 * Returns:     0 if the test succeeds, 1 if the test fails.
		 *
		 * ## NOTE ##	Be sure to specify start and end
		 *              addresses such that addr_mask has
		 *              lots of bits set. For example an
		 *              address range of 01000000 02000000 is
		 *              bad while a range of 01000000
		 *              01ffffff is perfect.
		 */
		addr_mask = ((ulong)end - (ulong)start)/sizeof(vu_long);
		pattern = (vu_long) 0xaaaaaaaa;
		anti_pattern = (vu_long) 0x55555555;

		debug("%s:%d: addr mask = 0x%.8lx\n",
			__FUNCTION__, __LINE__,
			addr_mask);
		/*
		 * Write the default pattern at each of the
		 * power-of-two offsets.
		 */
		for (offset = 1; (offset & addr_mask) != 0; offset <<= 1)
			start[offset] = pattern;

		/*
		 * Check for address bits stuck high.
		 */
		test_offset = 0;
		start[test_offset] = anti_pattern;

		for (offset = 1; (offset & addr_mask) != 0; offset <<= 1) {
		    temp = start[offset];
		    if (temp != pattern) {
			printf ("\nFAILURE: Address bit stuck high @ 0x%.8lx:"
				" expected 0x%.8lx, actual 0x%.8lx\n",
				(ulong)&start[offset], pattern, temp);
			return 1;
		    }
		}
		start[test_offset] = pattern;

		/*
		 * Check for addr bits stuck low or shorted.
		 */
		for (test_offset = 1; (test_offset & addr_mask) != 0; test_offset <<= 1) {
		    start[test_offset] = anti_pattern;

		    for (offset = 1; (offset & addr_mask) != 0; offset <<= 1) {
			temp = start[offset];
			if ((temp != pattern) && (offset != test_offset)) {
			    printf ("\nFAILURE: Address bit stuck low or shorted @"
				" 0x%.8lx: expected 0x%.8lx, actual 0x%.8lx\n",
				(ulong)&start[offset], pattern, temp);
			    return 1;
			}
		    }
		    start[test_offset] = pattern;
		}

		/*
		 * 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.
		 *
		 * Returns:     0 if the test succeeds, 1 if the test fails.
		 */
		num_words = ((ulong)end - (ulong)start)/sizeof(vu_long) + 1;

		/*
		 * Fill memory with a known pattern.
		 */
		for (pattern = 1, offset = 0; offset < num_words; pattern++, offset++) {
			start[offset] = pattern;
		}

		/*
		 * Check each location and invert it for the second pass.
		 */
		for (pattern = 1, offset = 0; offset < num_words; pattern++, offset++) {
		    temp = start[offset];
		    if (temp != pattern) {
			printf ("\nFAILURE (read/write) @ 0x%.8lx:"
				" expected 0x%.8lx, actual 0x%.8lx)\n",
				(ulong)&start[offset], pattern, temp);
			return 1;
		    }

		    anti_pattern = ~pattern;
		    start[offset] = anti_pattern;
		}

		/*
		 * Check each location for the inverted pattern and zero it.
		 */
		for (pattern = 1, offset = 0; offset < num_words; pattern++, offset++) {
		    anti_pattern = ~pattern;
		    temp = start[offset];
		    if (temp != anti_pattern) {
			printf ("\nFAILURE (read/write): @ 0x%.8lx:"
				" expected 0x%.8lx, actual 0x%.8lx)\n",
				(ulong)&start[offset], anti_pattern, temp);
			return 1;
		    }
		    start[offset] = 0;
		}
	}

}
#else
static int mem_test(ulong _start, ulong _end, ulong pattern)
{
	vu_long	*addr;
	vu_long *start = (vu_long *)_start;
	vu_long *end   = (vu_long *)_end;
	ulong	val;
	ulong	readback;
	ulong	incr;
	int rcode;

	incr = 1;
	for (;;) {
		if (ctrlc()) {
			putchar('\n');
			return 1;
		}

		printf ("\rPattern 0x%08lX  Writing..."
			"%12s"
			"\b\b\b\b\b\b\b\b\b\b",
			pattern, "");

		for (addr=start,val=pattern; addr<end; addr++) {
			*addr = val;
			val  += incr;
		}

		puts ("Reading...");

		for (addr=start,val=pattern; addr<end; addr++) {
			readback = *addr;
			if (readback != val) {
				printf ("\nMem error @ 0x%08X: "
					"found 0x%08lX, expected 0x%08lX\n",
					(uint)addr, readback, val);
				rcode = 1;
			}
			val += incr;
		}

		/*
		 * Flip the pattern each time to make lots of zeros and
		 * then, the next time, lots of ones.  We decrement
		 * the "negative" patterns and increment the "positive"
		 * patterns to preserve this feature.
		 */
		if(pattern & 0x80000000) {
			pattern = -pattern;	/* complement & increment */
		}
		else {
			pattern = ~pattern;
		}
		incr = -incr;
	}
	return rcode;
}
#endif

static int do_mem_mtest(int argc, char *argv[])
{
	ulong start, end, pattern = 0;

	if (argc < 3)
		return COMMAND_ERROR_USAGE;

	start = simple_strtoul(argv[1], NULL, 0);
	end = simple_strtoul(argv[2], NULL, 0);

	if (argc > 3)
		pattern = simple_strtoul(argv[3], NULL, 0);

	printf ("Testing 0x%08x ... 0x%08x:\n", (uint)start, (uint)end);
	
	return mem_test(start, end, pattern);
}

static const __maybe_unused char cmd_mtest_help[] =
"Usage: <start> <end> "
#ifdef CONFIG_CMD_MTEST_ALTERNATIVE
"[pattern]"
#endif
"\nsimple RAM read/write test\n";

BAREBOX_CMD_START(mtest)
	.cmd		= do_mem_mtest,
	.usage		= "simple RAM test",
	BAREBOX_CMD_HELP(cmd_mtest_help)
BAREBOX_CMD_END