1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CRC vpmsum tester
4 * Copyright 2017 Daniel Axtens, IBM Corporation.
5 */
6
7#include <linux/crc-t10dif.h>
8#include <linux/crc32.h>
9#include <crypto/internal/hash.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/random.h>
13#include <linux/string.h>
14#include <linux/kernel.h>
15#include <linux/cpufeature.h>
16#include <asm/switch_to.h>
17
18static unsigned long iterations = 10000;
19
20#define MAX_CRC_LENGTH 65535
21
22
23static int __init crc_test_init(void)
24{
25	u16 crc16 = 0, verify16 = 0;
26	__le32 verify32le = 0;
27	unsigned char *data;
28	u32 verify32 = 0;
29	unsigned long i;
30	__le32 crc32;
31	int ret;
32
33	struct crypto_shash *crct10dif_tfm;
34	struct crypto_shash *crc32c_tfm;
35
36	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
37		return -ENODEV;
38
39	data = kmalloc(MAX_CRC_LENGTH, GFP_KERNEL);
40	if (!data)
41		return -ENOMEM;
42
43	crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
44
45	if (IS_ERR(crct10dif_tfm)) {
46		pr_err("Error allocating crc-t10dif\n");
47		goto free_buf;
48	}
49
50	crc32c_tfm = crypto_alloc_shash("crc32c", 0, 0);
51
52	if (IS_ERR(crc32c_tfm)) {
53		pr_err("Error allocating crc32c\n");
54		goto free_16;
55	}
56
57	do {
58		SHASH_DESC_ON_STACK(crct10dif_shash, crct10dif_tfm);
59		SHASH_DESC_ON_STACK(crc32c_shash, crc32c_tfm);
60
61		crct10dif_shash->tfm = crct10dif_tfm;
62		ret = crypto_shash_init(crct10dif_shash);
63
64		if (ret) {
65			pr_err("Error initing crc-t10dif\n");
66			goto free_32;
67		}
68
69
70		crc32c_shash->tfm = crc32c_tfm;
71		ret = crypto_shash_init(crc32c_shash);
72
73		if (ret) {
74			pr_err("Error initing crc32c\n");
75			goto free_32;
76		}
77
78		pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
79		for (i=0; i<iterations; i++) {
80			size_t offset = get_random_u32_below(16);
81			size_t len = get_random_u32_below(MAX_CRC_LENGTH);
82
83			if (len <= offset)
84				continue;
85			get_random_bytes(data, len);
86			len -= offset;
87
88			crypto_shash_update(crct10dif_shash, data+offset, len);
89			crypto_shash_final(crct10dif_shash, (u8 *)(&crc16));
90			verify16 = crc_t10dif_generic(verify16, data+offset, len);
91
92
93			if (crc16 != verify16) {
94				pr_err("FAILURE in CRC16: got 0x%04x expected 0x%04x (len %lu)\n",
95				       crc16, verify16, len);
96				break;
97			}
98
99			crypto_shash_update(crc32c_shash, data+offset, len);
100			crypto_shash_final(crc32c_shash, (u8 *)(&crc32));
101			verify32 = le32_to_cpu(verify32le);
102		        verify32le = ~cpu_to_le32(__crc32c_le(~verify32, data+offset, len));
103			if (crc32 != verify32le) {
104				pr_err("FAILURE in CRC32: got 0x%08x expected 0x%08x (len %lu)\n",
105				       crc32, verify32, len);
106				break;
107			}
108		cond_resched();
109		}
110		pr_info("crc-vpmsum_test done, completed %lu iterations\n", i);
111	} while (0);
112
113free_32:
114	crypto_free_shash(crc32c_tfm);
115
116free_16:
117	crypto_free_shash(crct10dif_tfm);
118
119free_buf:
120	kfree(data);
121
122	return 0;
123}
124
125static void __exit crc_test_exit(void) {}
126
127module_init(crc_test_init);
128module_exit(crc_test_exit);
129module_param(iterations, long, 0400);
130
131MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
132MODULE_DESCRIPTION("Vector polynomial multiply-sum CRC tester");
133MODULE_LICENSE("GPL");
134