xref: /openbmc/linux/drivers/crypto/nx/nx-sha256.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
1 /**
2  * SHA-256 routines supporting the Power 7+ Nest Accelerators driver
3  *
4  * Copyright (C) 2011-2012 International Business Machines Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 only.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  *
19  * Author: Kent Yoder <yoder1@us.ibm.com>
20  */
21 
22 #include <crypto/internal/hash.h>
23 #include <crypto/sha.h>
24 #include <linux/module.h>
25 #include <asm/vio.h>
26 #include <asm/byteorder.h>
27 
28 #include "nx_csbcpb.h"
29 #include "nx.h"
30 
31 
32 static int nx_crypto_ctx_sha256_init(struct crypto_tfm *tfm)
33 {
34 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
35 	int err;
36 
37 	err = nx_crypto_ctx_sha_init(tfm);
38 	if (err)
39 		return err;
40 
41 	nx_ctx_init(nx_ctx, HCOP_FC_SHA);
42 
43 	nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];
44 
45 	NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
46 
47 	return 0;
48 }
49 
50 static int nx_sha256_init(struct shash_desc *desc) {
51 	struct sha256_state *sctx = shash_desc_ctx(desc);
52 
53 	memset(sctx, 0, sizeof *sctx);
54 
55 	sctx->state[0] = __cpu_to_be32(SHA256_H0);
56 	sctx->state[1] = __cpu_to_be32(SHA256_H1);
57 	sctx->state[2] = __cpu_to_be32(SHA256_H2);
58 	sctx->state[3] = __cpu_to_be32(SHA256_H3);
59 	sctx->state[4] = __cpu_to_be32(SHA256_H4);
60 	sctx->state[5] = __cpu_to_be32(SHA256_H5);
61 	sctx->state[6] = __cpu_to_be32(SHA256_H6);
62 	sctx->state[7] = __cpu_to_be32(SHA256_H7);
63 	sctx->count = 0;
64 
65 	return 0;
66 }
67 
68 static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
69 			    unsigned int len)
70 {
71 	struct sha256_state *sctx = shash_desc_ctx(desc);
72 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
73 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
74 	struct nx_sg *in_sg;
75 	struct nx_sg *out_sg;
76 	u64 to_process = 0, leftover, total;
77 	unsigned long irq_flags;
78 	int rc = 0;
79 	int data_len;
80 	u32 max_sg_len;
81 	u64 buf_len = (sctx->count % SHA256_BLOCK_SIZE);
82 
83 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
84 
85 	/* 2 cases for total data len:
86 	 *  1: < SHA256_BLOCK_SIZE: copy into state, return 0
87 	 *  2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
88 	 */
89 	total = (sctx->count % SHA256_BLOCK_SIZE) + len;
90 	if (total < SHA256_BLOCK_SIZE) {
91 		memcpy(sctx->buf + buf_len, data, len);
92 		sctx->count += len;
93 		goto out;
94 	}
95 
96 	memcpy(csbcpb->cpb.sha256.message_digest, sctx->state, SHA256_DIGEST_SIZE);
97 	NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
98 	NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
99 
100 	in_sg = nx_ctx->in_sg;
101 	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
102 			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
103 	max_sg_len = min_t(u64, max_sg_len,
104 			nx_ctx->ap->databytelen/NX_PAGE_SIZE);
105 
106 	data_len = SHA256_DIGEST_SIZE;
107 	out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
108 				  &data_len, max_sg_len);
109 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
110 
111 	if (data_len != SHA256_DIGEST_SIZE) {
112 		rc = -EINVAL;
113 		goto out;
114 	}
115 
116 	do {
117 		/*
118 		 * to_process: the SHA256_BLOCK_SIZE data chunk to process in
119 		 * this update. This value is also restricted by the sg list
120 		 * limits.
121 		 */
122 		to_process = total - to_process;
123 		to_process = to_process & ~(SHA256_BLOCK_SIZE - 1);
124 
125 		if (buf_len) {
126 			data_len = buf_len;
127 			in_sg = nx_build_sg_list(nx_ctx->in_sg,
128 						 (u8 *) sctx->buf,
129 						 &data_len,
130 						 max_sg_len);
131 
132 			if (data_len != buf_len) {
133 				rc = -EINVAL;
134 				goto out;
135 			}
136 		}
137 
138 		data_len = to_process - buf_len;
139 		in_sg = nx_build_sg_list(in_sg, (u8 *) data,
140 					 &data_len, max_sg_len);
141 
142 		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
143 
144 		to_process = (data_len + buf_len);
145 		leftover = total - to_process;
146 
147 		/*
148 		 * we've hit the nx chip previously and we're updating
149 		 * again, so copy over the partial digest.
150 		 */
151 		memcpy(csbcpb->cpb.sha256.input_partial_digest,
152 			       csbcpb->cpb.sha256.message_digest,
153 			       SHA256_DIGEST_SIZE);
154 
155 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
156 			rc = -EINVAL;
157 			goto out;
158 		}
159 
160 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
161 				   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
162 		if (rc)
163 			goto out;
164 
165 		atomic_inc(&(nx_ctx->stats->sha256_ops));
166 
167 		total -= to_process;
168 		data += to_process - buf_len;
169 		buf_len = 0;
170 
171 	} while (leftover >= SHA256_BLOCK_SIZE);
172 
173 	/* copy the leftover back into the state struct */
174 	if (leftover)
175 		memcpy(sctx->buf, data, leftover);
176 
177 	sctx->count += len;
178 	memcpy(sctx->state, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
179 out:
180 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
181 	return rc;
182 }
183 
184 static int nx_sha256_final(struct shash_desc *desc, u8 *out)
185 {
186 	struct sha256_state *sctx = shash_desc_ctx(desc);
187 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
188 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
189 	struct nx_sg *in_sg, *out_sg;
190 	unsigned long irq_flags;
191 	u32 max_sg_len;
192 	int rc = 0;
193 	int len;
194 
195 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
196 
197 	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
198 			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
199 	max_sg_len = min_t(u64, max_sg_len,
200 			nx_ctx->ap->databytelen/NX_PAGE_SIZE);
201 
202 	/* final is represented by continuing the operation and indicating that
203 	 * this is not an intermediate operation */
204 	if (sctx->count >= SHA256_BLOCK_SIZE) {
205 		/* we've hit the nx chip previously, now we're finalizing,
206 		 * so copy over the partial digest */
207 		memcpy(csbcpb->cpb.sha256.input_partial_digest, sctx->state, SHA256_DIGEST_SIZE);
208 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
209 		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
210 	} else {
211 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
212 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
213 	}
214 
215 	csbcpb->cpb.sha256.message_bit_length = (u64) (sctx->count * 8);
216 
217 	len = sctx->count & (SHA256_BLOCK_SIZE - 1);
218 	in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) sctx->buf,
219 				 &len, max_sg_len);
220 
221 	if (len != (sctx->count & (SHA256_BLOCK_SIZE - 1))) {
222 		rc = -EINVAL;
223 		goto out;
224 	}
225 
226 	len = SHA256_DIGEST_SIZE;
227 	out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len, max_sg_len);
228 
229 	if (len != SHA256_DIGEST_SIZE) {
230 		rc = -EINVAL;
231 		goto out;
232 	}
233 
234 	nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
235 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
236 	if (!nx_ctx->op.outlen) {
237 		rc = -EINVAL;
238 		goto out;
239 	}
240 
241 	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
242 			   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
243 	if (rc)
244 		goto out;
245 
246 	atomic_inc(&(nx_ctx->stats->sha256_ops));
247 
248 	atomic64_add(sctx->count, &(nx_ctx->stats->sha256_bytes));
249 	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
250 out:
251 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
252 	return rc;
253 }
254 
255 static int nx_sha256_export(struct shash_desc *desc, void *out)
256 {
257 	struct sha256_state *sctx = shash_desc_ctx(desc);
258 
259 	memcpy(out, sctx, sizeof(*sctx));
260 
261 	return 0;
262 }
263 
264 static int nx_sha256_import(struct shash_desc *desc, const void *in)
265 {
266 	struct sha256_state *sctx = shash_desc_ctx(desc);
267 
268 	memcpy(sctx, in, sizeof(*sctx));
269 
270 	return 0;
271 }
272 
273 struct shash_alg nx_shash_sha256_alg = {
274 	.digestsize = SHA256_DIGEST_SIZE,
275 	.init       = nx_sha256_init,
276 	.update     = nx_sha256_update,
277 	.final      = nx_sha256_final,
278 	.export     = nx_sha256_export,
279 	.import     = nx_sha256_import,
280 	.descsize   = sizeof(struct sha256_state),
281 	.statesize  = sizeof(struct sha256_state),
282 	.base       = {
283 		.cra_name        = "sha256",
284 		.cra_driver_name = "sha256-nx",
285 		.cra_priority    = 300,
286 		.cra_flags       = CRYPTO_ALG_TYPE_SHASH,
287 		.cra_blocksize   = SHA256_BLOCK_SIZE,
288 		.cra_module      = THIS_MODULE,
289 		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
290 		.cra_init        = nx_crypto_ctx_sha256_init,
291 		.cra_exit        = nx_crypto_ctx_exit,
292 	}
293 };
294