1 /*
2  * CRC vpmsum tester
3  * Copyright 2017 Daniel Axtens, IBM Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/crc-t10dif.h>
11 #include <linux/crc32.h>
12 #include <crypto/internal/hash.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16 #include <linux/kernel.h>
17 #include <linux/cpufeature.h>
18 #include <asm/switch_to.h>
19 
20 static unsigned long iterations = 10000;
21 
22 #define MAX_CRC_LENGTH 65535
23 
24 
25 static int __init crc_test_init(void)
26 {
27 	u16 crc16 = 0, verify16 = 0;
28 	u32 crc32 = 0, verify32 = 0;
29 	__le32 verify32le = 0;
30 	unsigned char *data;
31 	unsigned long i;
32 	int ret;
33 
34 	struct crypto_shash *crct10dif_tfm;
35 	struct crypto_shash *crc32c_tfm;
36 
37 	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
38 		return -ENODEV;
39 
40 	data = kmalloc(MAX_CRC_LENGTH, GFP_KERNEL);
41 	if (!data)
42 		return -ENOMEM;
43 
44 	crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
45 
46 	if (IS_ERR(crct10dif_tfm)) {
47 		pr_err("Error allocating crc-t10dif\n");
48 		goto free_buf;
49 	}
50 
51 	crc32c_tfm = crypto_alloc_shash("crc32c", 0, 0);
52 
53 	if (IS_ERR(crc32c_tfm)) {
54 		pr_err("Error allocating crc32c\n");
55 		goto free_16;
56 	}
57 
58 	do {
59 		SHASH_DESC_ON_STACK(crct10dif_shash, crct10dif_tfm);
60 		SHASH_DESC_ON_STACK(crc32c_shash, crc32c_tfm);
61 
62 		crct10dif_shash->tfm = crct10dif_tfm;
63 		ret = crypto_shash_init(crct10dif_shash);
64 
65 		if (ret) {
66 			pr_err("Error initing crc-t10dif\n");
67 			goto free_32;
68 		}
69 
70 
71 		crc32c_shash->tfm = crc32c_tfm;
72 		ret = crypto_shash_init(crc32c_shash);
73 
74 		if (ret) {
75 			pr_err("Error initing crc32c\n");
76 			goto free_32;
77 		}
78 
79 		pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
80 		for (i=0; i<iterations; i++) {
81 			size_t len, offset;
82 
83 			get_random_bytes(data, MAX_CRC_LENGTH);
84 			get_random_bytes(&len, sizeof(len));
85 			get_random_bytes(&offset, sizeof(offset));
86 
87 			len %= MAX_CRC_LENGTH;
88 			offset &= 15;
89 			if (len <= offset)
90 				continue;
91 			len -= offset;
92 
93 			crypto_shash_update(crct10dif_shash, data+offset, len);
94 			crypto_shash_final(crct10dif_shash, (u8 *)(&crc16));
95 			verify16 = crc_t10dif_generic(verify16, data+offset, len);
96 
97 
98 			if (crc16 != verify16) {
99 				pr_err("FAILURE in CRC16: got 0x%04x expected 0x%04x (len %lu)\n",
100 				       crc16, verify16, len);
101 				break;
102 			}
103 
104 			crypto_shash_update(crc32c_shash, data+offset, len);
105 			crypto_shash_final(crc32c_shash, (u8 *)(&crc32));
106 			verify32 = le32_to_cpu(verify32le);
107 		        verify32le = ~cpu_to_le32(__crc32c_le(~verify32, data+offset, len));
108 			if (crc32 != (u32)verify32le) {
109 				pr_err("FAILURE in CRC32: got 0x%08x expected 0x%08x (len %lu)\n",
110 				       crc32, verify32, len);
111 				break;
112 			}
113 		}
114 		pr_info("crc-vpmsum_test done, completed %lu iterations\n", i);
115 	} while (0);
116 
117 free_32:
118 	crypto_free_shash(crc32c_tfm);
119 
120 free_16:
121 	crypto_free_shash(crct10dif_tfm);
122 
123 free_buf:
124 	kfree(data);
125 
126 	return 0;
127 }
128 
129 static void __exit crc_test_exit(void) {}
130 
131 module_init(crc_test_init);
132 module_exit(crc_test_exit);
133 module_param(iterations, long, 0400);
134 
135 MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
136 MODULE_DESCRIPTION("Vector polynomial multiply-sum CRC tester");
137 MODULE_LICENSE("GPL");
138