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 
cbc_aes_nx_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)21 static int cbc_aes_nx_set_key(struct crypto_skcipher *tfm,
22 			      const u8               *in_key,
23 			      unsigned int            key_len)
24 {
25 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_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 
cbc_aes_nx_crypt(struct skcipher_request * req,int enc)53 static int cbc_aes_nx_crypt(struct skcipher_request *req,
54 			    int                      enc)
55 {
56 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
57 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
58 	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
59 	unsigned long irq_flags;
60 	unsigned int processed = 0, to_process;
61 	int rc;
62 
63 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
64 
65 	if (enc)
66 		NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
67 	else
68 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
69 
70 	do {
71 		to_process = req->cryptlen - processed;
72 
73 		rc = nx_build_sg_lists(nx_ctx, req->iv, req->dst, req->src,
74 				       &to_process, processed,
75 				       csbcpb->cpb.aes_cbc.iv);
76 		if (rc)
77 			goto out;
78 
79 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
80 			rc = -EINVAL;
81 			goto out;
82 		}
83 
84 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
85 				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
86 		if (rc)
87 			goto out;
88 
89 		memcpy(req->iv, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
90 		atomic_inc(&(nx_ctx->stats->aes_ops));
91 		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
92 			     &(nx_ctx->stats->aes_bytes));
93 
94 		processed += to_process;
95 	} while (processed < req->cryptlen);
96 out:
97 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
98 	return rc;
99 }
100 
cbc_aes_nx_encrypt(struct skcipher_request * req)101 static int cbc_aes_nx_encrypt(struct skcipher_request *req)
102 {
103 	return cbc_aes_nx_crypt(req, 1);
104 }
105 
cbc_aes_nx_decrypt(struct skcipher_request * req)106 static int cbc_aes_nx_decrypt(struct skcipher_request *req)
107 {
108 	return cbc_aes_nx_crypt(req, 0);
109 }
110 
111 struct skcipher_alg nx_cbc_aes_alg = {
112 	.base.cra_name		= "cbc(aes)",
113 	.base.cra_driver_name	= "cbc-aes-nx",
114 	.base.cra_priority	= 300,
115 	.base.cra_blocksize	= AES_BLOCK_SIZE,
116 	.base.cra_ctxsize	= sizeof(struct nx_crypto_ctx),
117 	.base.cra_alignmask	= 0xf,
118 	.base.cra_module	= THIS_MODULE,
119 	.init			= nx_crypto_ctx_aes_cbc_init,
120 	.exit			= nx_crypto_ctx_skcipher_exit,
121 	.min_keysize		= AES_MIN_KEY_SIZE,
122 	.max_keysize		= AES_MAX_KEY_SIZE,
123 	.ivsize			= AES_BLOCK_SIZE,
124 	.setkey			= cbc_aes_nx_set_key,
125 	.encrypt		= cbc_aes_nx_encrypt,
126 	.decrypt		= cbc_aes_nx_decrypt,
127 };
128