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/string.h>
13 #include <linux/kernel.h>
14 #include <linux/cpufeature.h>
15 #include <asm/switch_to.h>
16 
17 static unsigned long iterations = 10000;
18 
19 #define MAX_CRC_LENGTH 65535
20 
21 
22 static int __init crc_test_init(void)
23 {
24 	u16 crc16 = 0, verify16 = 0;
25 	u32 crc32 = 0, verify32 = 0;
26 	__le32 verify32le = 0;
27 	unsigned char *data;
28 	unsigned long i;
29 	int ret;
30 
31 	struct crypto_shash *crct10dif_tfm;
32 	struct crypto_shash *crc32c_tfm;
33 
34 	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
35 		return -ENODEV;
36 
37 	data = kmalloc(MAX_CRC_LENGTH, GFP_KERNEL);
38 	if (!data)
39 		return -ENOMEM;
40 
41 	crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
42 
43 	if (IS_ERR(crct10dif_tfm)) {
44 		pr_err("Error allocating crc-t10dif\n");
45 		goto free_buf;
46 	}
47 
48 	crc32c_tfm = crypto_alloc_shash("crc32c", 0, 0);
49 
50 	if (IS_ERR(crc32c_tfm)) {
51 		pr_err("Error allocating crc32c\n");
52 		goto free_16;
53 	}
54 
55 	do {
56 		SHASH_DESC_ON_STACK(crct10dif_shash, crct10dif_tfm);
57 		SHASH_DESC_ON_STACK(crc32c_shash, crc32c_tfm);
58 
59 		crct10dif_shash->tfm = crct10dif_tfm;
60 		ret = crypto_shash_init(crct10dif_shash);
61 
62 		if (ret) {
63 			pr_err("Error initing crc-t10dif\n");
64 			goto free_32;
65 		}
66 
67 
68 		crc32c_shash->tfm = crc32c_tfm;
69 		ret = crypto_shash_init(crc32c_shash);
70 
71 		if (ret) {
72 			pr_err("Error initing crc32c\n");
73 			goto free_32;
74 		}
75 
76 		pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
77 		for (i=0; i<iterations; i++) {
78 			size_t offset = prandom_u32_max(16);
79 			size_t len = prandom_u32_max(MAX_CRC_LENGTH);
80 
81 			if (len <= offset)
82 				continue;
83 			prandom_bytes(data, len);
84 			len -= offset;
85 
86 			crypto_shash_update(crct10dif_shash, data+offset, len);
87 			crypto_shash_final(crct10dif_shash, (u8 *)(&crc16));
88 			verify16 = crc_t10dif_generic(verify16, data+offset, len);
89 
90 
91 			if (crc16 != verify16) {
92 				pr_err("FAILURE in CRC16: got 0x%04x expected 0x%04x (len %lu)\n",
93 				       crc16, verify16, len);
94 				break;
95 			}
96 
97 			crypto_shash_update(crc32c_shash, data+offset, len);
98 			crypto_shash_final(crc32c_shash, (u8 *)(&crc32));
99 			verify32 = le32_to_cpu(verify32le);
100 		        verify32le = ~cpu_to_le32(__crc32c_le(~verify32, data+offset, len));
101 			if (crc32 != (u32)verify32le) {
102 				pr_err("FAILURE in CRC32: got 0x%08x expected 0x%08x (len %lu)\n",
103 				       crc32, verify32, len);
104 				break;
105 			}
106 		}
107 		pr_info("crc-vpmsum_test done, completed %lu iterations\n", i);
108 	} while (0);
109 
110 free_32:
111 	crypto_free_shash(crc32c_tfm);
112 
113 free_16:
114 	crypto_free_shash(crct10dif_tfm);
115 
116 free_buf:
117 	kfree(data);
118 
119 	return 0;
120 }
121 
122 static void __exit crc_test_exit(void) {}
123 
124 module_init(crc_test_init);
125 module_exit(crc_test_exit);
126 module_param(iterations, long, 0400);
127 
128 MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
129 MODULE_DESCRIPTION("Vector polynomial multiply-sum CRC tester");
130 MODULE_LICENSE("GPL");
131