Re: [PATCH 05/17] Blackfin: convert to generic checksum code

[Mike Frysinger <vapier.adi@gmail.com>]

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On Fri, Jun 19, 2009 at 08:33, Arnd Bergmann wrote:
> On Friday 19 June 2009, Mike Frysinger wrote:
>> On Fri, Jun 19, 2009 at 05:05, Arnd Bergmann wrote:
>> > x86 and blackfin are both little-endian, so your variant is correct
>> > there. They add the 0x01 to the low byte of the 16-bit word, while
>> > on big-endian machines, you have to add it to the high byte.
>>
>> can we think of enough simple examples to through together an optional
>> boot-time self test ?
>
> sounds like a good idea.

how about the attached

> lib/checksum.c: Fix another endianess bug

hrm, still not quite :/

the attached test code shows failures in every case
-mike

[-- Attachment #2: checksum-selftest.c --]
[-- Type: text/x-csrc, Size: 3194 bytes --]

/*
 * Networking checksum self checks.
 *
 * Licensed under the GPL-2.
 */

#define pr_fmt(fmt) "csum-selftest: " fmt

#include <linux/kernel.h>
#include <net/checksum.h>

extern unsigned short do_csum(const unsigned char *buff, int len);

struct do_csum_data {
	unsigned short ret;
	unsigned char *buf;
	int len;
};
#define DO_CSUM_DATA(_num, _ret) \
{	\
	.ret = _ret, \
	.buf = do_csum_data##_num, \
	.len = ARRAY_SIZE(do_csum_data##_num), \
}
static unsigned char __initdata do_csum_data1[] = {
	0x20,
};
static unsigned char __initdata do_csum_data2[] = {
	0x0d, 0x0a,
};
static unsigned char __initdata do_csum_data3[] = {
	0xff, 0xfb, 0x01,
};
static unsigned char __initdata do_csum_data5[] = {
	0x67, 0x72, 0x5d, 0x0d, 0x00,
};
static unsigned char __initdata do_csum_data7[] = {
	0x20, 0x20, 0x20, 0x35, 0x37, 0x20, 0x20,
};
static unsigned char __initdata do_csum_data255[] = {
	0x20, 0x34, 0x34, 0x34, 0x20, 0x53, 0x20, 0x20, 0x20, 0x20, 0x2d,
	0x2f, 0x62, 0x69, 0x6e, 0x2f, 0x73, 0x68, 0x20, 0x0d, 0x0a, 0x20,
	0x20, 0x31, 0x30, 0x35, 0x20, 0x72, 0x6f, 0x6f, 0x74, 0x20, 0x20,
	0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x34, 0x34, 0x20, 0x53, 0x20,
	0x20, 0x20, 0x20, 0x2f, 0x73, 0x62, 0x69, 0x6e, 0x2f, 0x69, 0x6e,
	0x65, 0x74, 0x64, 0x20, 0x0d, 0x0a, 0x20, 0x20, 0x31, 0x30, 0x36,
	0x20, 0x72, 0x6f, 0x6f, 0x74, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
	0x20, 0x34, 0x33, 0x36, 0x20, 0x53, 0x20, 0x20, 0x20, 0x20, 0x2f,
	0x73, 0x62, 0x69, 0x6e, 0x2f, 0x73, 0x79, 0x73, 0x6c, 0x6f, 0x67,
	0x64, 0x20, 0x2d, 0x6e, 0x20, 0x0d, 0x0a, 0x20, 0x20, 0x31, 0x30,
	0x37, 0x20, 0x72, 0x6f, 0x6f, 0x74, 0x20, 0x20, 0x20, 0x20, 0x20,
	0x20, 0x20, 0x34, 0x33, 0x32, 0x20, 0x52, 0x20, 0x20, 0x20, 0x20,
	0x2f, 0x73, 0x62, 0x69, 0x6e, 0x2f, 0x6b, 0x6c, 0x6f, 0x67, 0x64,
	0x20, 0x2d, 0x6e, 0x20, 0x0d, 0x0a, 0x20, 0x20, 0x31, 0x30, 0x38,
	0x20, 0x72, 0x6f, 0x6f, 0x74, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
	0x20, 0x20, 0x33, 0x32, 0x20, 0x53, 0x20, 0x20, 0x20, 0x20, 0x2f,
	0x62, 0x69, 0x6e, 0x2f, 0x77, 0x61, 0x74, 0x63, 0x68, 0x64, 0x6f,
	0x67, 0x64, 0x20, 0x2d, 0x66, 0x20, 0x2d, 0x73, 0x20, 0x0d, 0x0a,
	0x20, 0x20, 0x31, 0x30, 0x39, 0x20, 0x72, 0x6f, 0x6f, 0x74, 0x20,
	0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x35, 0x36, 0x20, 0x52,
	0x20, 0x20, 0x20, 0x20, 0x2f, 0x62, 0x69, 0x6e, 0x2f, 0x74, 0x65,
	0x6c, 0x6e, 0x65, 0x74, 0x64, 0x20, 0x0d, 0x0a, 0x20, 0x20, 0x31,
	0x31, 0x30, 0x20, 0x72, 0x6f, 0x6f, 0x74, 0x20, 0x20, 0x20, 0x20,
	0x20, 0x20
};
static struct do_csum_data __initdata do_csum_data[] = {
	DO_CSUM_DATA(1, 0x0020),
	DO_CSUM_DATA(2, 0xfc00),
	DO_CSUM_DATA(3, 0x0a0d),
	DO_CSUM_DATA(5, 0x7fc4),
	DO_CSUM_DATA(7, 0x7597),
	DO_CSUM_DATA(255, 0x4f96),
};

static int __init do_csum_selftest(void)
{
	int i, ret;
	unsigned short tret;

	ret = 0;
	for (i = 0; i < ARRAY_SIZE(do_csum_data); ++i) {
		tret = do_csum(do_csum_data[i].buf, do_csum_data[i].len);
		if (tret != do_csum_data[i].ret) {
			pr_err("%s: test %i: %#x != %#x: FAIL\n",
				__func__, i, tret, do_csum_data[i].ret);
			ret = 1;
		}
	}

	return ret;
}

static int __init csum_selftest_init(void)
{
	int ret = do_csum_selftest();

	if (!ret)
		pr_info("all tests passed!\n");

	return 0;
}
module_init(csum_selftest_init);