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
21static 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
53static 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);
96out:
97	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
98	return rc;
99}
100
101static int cbc_aes_nx_encrypt(struct skcipher_request *req)
102{
103	return cbc_aes_nx_crypt(req, 1);
104}
105
106static int cbc_aes_nx_decrypt(struct skcipher_request *req)
107{
108	return cbc_aes_nx_crypt(req, 0);
109}
110
111struct 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