xref: /linux/drivers/crypto/nx/nx-aes-cbc.c (revision fcab107abe1ab5be9dbe874baa722372da8f4f73)
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/internal/skcipher.h>
12 #include <linux/err.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/spinlock.h>
16 #include <linux/string.h>
17 #include <asm/vio.h>
18 
19 #include "nx_csbcpb.h"
20 #include "nx.h"
21 
22 
23 static int cbc_aes_nx_set_key(struct crypto_skcipher *tfm,
24 			      const u8               *in_key,
25 			      unsigned int            key_len)
26 {
27 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
28 	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
29 
30 	nx_ctx_init(nx_ctx, HCOP_FC_AES);
31 
32 	switch (key_len) {
33 	case AES_KEYSIZE_128:
34 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
35 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
36 		break;
37 	case AES_KEYSIZE_192:
38 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
39 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
40 		break;
41 	case AES_KEYSIZE_256:
42 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
43 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
44 		break;
45 	default:
46 		return -EINVAL;
47 	}
48 
49 	csbcpb->cpb.hdr.mode = NX_MODE_AES_CBC;
50 	memcpy(csbcpb->cpb.aes_cbc.key, in_key, key_len);
51 
52 	return 0;
53 }
54 
55 static int cbc_aes_nx_crypt(struct skcipher_request *req,
56 			    int                      enc)
57 {
58 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
59 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(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 = req->cryptlen - processed;
74 
75 		rc = nx_build_sg_lists(nx_ctx, req->iv, req->dst, req->src,
76 				       &to_process, processed,
77 				       csbcpb->cpb.aes_cbc.iv);
78 		if (rc)
79 			goto out;
80 
81 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
82 			rc = -EINVAL;
83 			goto out;
84 		}
85 
86 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
87 				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
88 		if (rc)
89 			goto out;
90 
91 		memcpy(req->iv, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
92 		atomic_inc(&(nx_ctx->stats->aes_ops));
93 		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
94 			     &(nx_ctx->stats->aes_bytes));
95 
96 		processed += to_process;
97 	} while (processed < req->cryptlen);
98 out:
99 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
100 	return rc;
101 }
102 
103 static int cbc_aes_nx_encrypt(struct skcipher_request *req)
104 {
105 	return cbc_aes_nx_crypt(req, 1);
106 }
107 
108 static int cbc_aes_nx_decrypt(struct skcipher_request *req)
109 {
110 	return cbc_aes_nx_crypt(req, 0);
111 }
112 
113 struct skcipher_alg nx_cbc_aes_alg = {
114 	.base.cra_name		= "cbc(aes)",
115 	.base.cra_driver_name	= "cbc-aes-nx",
116 	.base.cra_priority	= 300,
117 	.base.cra_blocksize	= AES_BLOCK_SIZE,
118 	.base.cra_ctxsize	= sizeof(struct nx_crypto_ctx),
119 	.base.cra_alignmask	= 0xf,
120 	.base.cra_module	= THIS_MODULE,
121 	.init			= nx_crypto_ctx_aes_cbc_init,
122 	.exit			= nx_crypto_ctx_skcipher_exit,
123 	.min_keysize		= AES_MIN_KEY_SIZE,
124 	.max_keysize		= AES_MAX_KEY_SIZE,
125 	.ivsize			= AES_BLOCK_SIZE,
126 	.setkey			= cbc_aes_nx_set_key,
127 	.encrypt		= cbc_aes_nx_encrypt,
128 	.decrypt		= cbc_aes_nx_decrypt,
129 };
130