xref: /linux/drivers/crypto/nx/nx-aes-cbc.c (revision 75a6faf617d107bdbc74d36ccf89f2280b96ac26)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /**
3  * AES CBC routines supporting the Power 7+ Nest Accelerators driver
4  *
5  * Copyright (C) 2011-2012 International Business Machines Inc.
6  *
7  * Author: Kent Yoder <yoder1@us.ibm.com>
8  */
9 
10 #include <crypto/aes.h>
11 #include <crypto/algapi.h>
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/crypto.h>
15 #include <asm/vio.h>
16 
17 #include "nx_csbcpb.h"
18 #include "nx.h"
19 
20 
21 static int cbc_aes_nx_set_key(struct crypto_tfm *tfm,
22 			      const u8          *in_key,
23 			      unsigned int       key_len)
24 {
25 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
26 	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
27 
28 	nx_ctx_init(nx_ctx, HCOP_FC_AES);
29 
30 	switch (key_len) {
31 	case AES_KEYSIZE_128:
32 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
33 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
34 		break;
35 	case AES_KEYSIZE_192:
36 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
37 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
38 		break;
39 	case AES_KEYSIZE_256:
40 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
41 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
42 		break;
43 	default:
44 		return -EINVAL;
45 	}
46 
47 	csbcpb->cpb.hdr.mode = NX_MODE_AES_CBC;
48 	memcpy(csbcpb->cpb.aes_cbc.key, in_key, key_len);
49 
50 	return 0;
51 }
52 
53 static int cbc_aes_nx_crypt(struct blkcipher_desc *desc,
54 			    struct scatterlist    *dst,
55 			    struct scatterlist    *src,
56 			    unsigned int           nbytes,
57 			    int                    enc)
58 {
59 	struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
60 	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
61 	unsigned long irq_flags;
62 	unsigned int processed = 0, to_process;
63 	int rc;
64 
65 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
66 
67 	if (enc)
68 		NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
69 	else
70 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
71 
72 	do {
73 		to_process = nbytes - processed;
74 
75 		rc = nx_build_sg_lists(nx_ctx, desc, dst, src, &to_process,
76 				       processed, csbcpb->cpb.aes_cbc.iv);
77 		if (rc)
78 			goto out;
79 
80 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
81 			rc = -EINVAL;
82 			goto out;
83 		}
84 
85 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
86 				   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
87 		if (rc)
88 			goto out;
89 
90 		memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
91 		atomic_inc(&(nx_ctx->stats->aes_ops));
92 		atomic64_add(csbcpb->csb.processed_byte_count,
93 			     &(nx_ctx->stats->aes_bytes));
94 
95 		processed += to_process;
96 	} while (processed < nbytes);
97 out:
98 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
99 	return rc;
100 }
101 
102 static int cbc_aes_nx_encrypt(struct blkcipher_desc *desc,
103 			      struct scatterlist    *dst,
104 			      struct scatterlist    *src,
105 			      unsigned int           nbytes)
106 {
107 	return cbc_aes_nx_crypt(desc, dst, src, nbytes, 1);
108 }
109 
110 static int cbc_aes_nx_decrypt(struct blkcipher_desc *desc,
111 			      struct scatterlist    *dst,
112 			      struct scatterlist    *src,
113 			      unsigned int           nbytes)
114 {
115 	return cbc_aes_nx_crypt(desc, dst, src, nbytes, 0);
116 }
117 
118 struct crypto_alg nx_cbc_aes_alg = {
119 	.cra_name        = "cbc(aes)",
120 	.cra_driver_name = "cbc-aes-nx",
121 	.cra_priority    = 300,
122 	.cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
123 	.cra_blocksize   = AES_BLOCK_SIZE,
124 	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
125 	.cra_type        = &crypto_blkcipher_type,
126 	.cra_alignmask   = 0xf,
127 	.cra_module      = THIS_MODULE,
128 	.cra_init        = nx_crypto_ctx_aes_cbc_init,
129 	.cra_exit        = nx_crypto_ctx_exit,
130 	.cra_blkcipher = {
131 		.min_keysize = AES_MIN_KEY_SIZE,
132 		.max_keysize = AES_MAX_KEY_SIZE,
133 		.ivsize      = AES_BLOCK_SIZE,
134 		.setkey      = cbc_aes_nx_set_key,
135 		.encrypt     = cbc_aes_nx_encrypt,
136 		.decrypt     = cbc_aes_nx_decrypt,
137 	}
138 };
139