xref: /openbmc/linux/drivers/crypto/nx/nx-sha256.c (revision f7777dcc)
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 
27 #include "nx_csbcpb.h"
28 #include "nx.h"
29 
30 
31 static int nx_sha256_init(struct shash_desc *desc)
32 {
33 	struct sha256_state *sctx = shash_desc_ctx(desc);
34 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
35 	struct nx_sg *out_sg;
36 
37 	nx_ctx_init(nx_ctx, HCOP_FC_SHA);
38 
39 	memset(sctx, 0, sizeof *sctx);
40 
41 	nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];
42 
43 	NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
44 	out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
45 				  SHA256_DIGEST_SIZE, nx_ctx->ap->sglen);
46 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
47 
48 	return 0;
49 }
50 
51 static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
52 			    unsigned int len)
53 {
54 	struct sha256_state *sctx = shash_desc_ctx(desc);
55 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
56 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
57 	struct nx_sg *in_sg;
58 	u64 to_process, leftover, total;
59 	u32 max_sg_len;
60 	unsigned long irq_flags;
61 	int rc = 0;
62 
63 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
64 
65 	/* 2 cases for total data len:
66 	 *  1: < SHA256_BLOCK_SIZE: copy into state, return 0
67 	 *  2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
68 	 */
69 	total = sctx->count + len;
70 	if (total < SHA256_BLOCK_SIZE) {
71 		memcpy(sctx->buf + sctx->count, data, len);
72 		sctx->count += len;
73 		goto out;
74 	}
75 
76 	in_sg = nx_ctx->in_sg;
77 	max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
78 			   nx_ctx->ap->sglen);
79 
80 	do {
81 		/*
82 		 * to_process: the SHA256_BLOCK_SIZE data chunk to process in
83 		 * this update. This value is also restricted by the sg list
84 		 * limits.
85 		 */
86 		to_process = min_t(u64, total, nx_ctx->ap->databytelen);
87 		to_process = min_t(u64, to_process,
88 				   NX_PAGE_SIZE * (max_sg_len - 1));
89 		to_process = to_process & ~(SHA256_BLOCK_SIZE - 1);
90 		leftover = total - to_process;
91 
92 		if (sctx->count) {
93 			in_sg = nx_build_sg_list(nx_ctx->in_sg,
94 						 (u8 *) sctx->buf,
95 						 sctx->count, max_sg_len);
96 		}
97 		in_sg = nx_build_sg_list(in_sg, (u8 *) data,
98 					 to_process - sctx->count,
99 					 max_sg_len);
100 		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
101 					sizeof(struct nx_sg);
102 
103 		if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
104 			/*
105 			 * we've hit the nx chip previously and we're updating
106 			 * again, so copy over the partial digest.
107 			 */
108 			memcpy(csbcpb->cpb.sha256.input_partial_digest,
109 			       csbcpb->cpb.sha256.message_digest,
110 			       SHA256_DIGEST_SIZE);
111 		}
112 
113 		NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
114 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
115 			rc = -EINVAL;
116 			goto out;
117 		}
118 
119 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
120 				   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
121 		if (rc)
122 			goto out;
123 
124 		atomic_inc(&(nx_ctx->stats->sha256_ops));
125 		csbcpb->cpb.sha256.message_bit_length += (u64)
126 			(csbcpb->cpb.sha256.spbc * 8);
127 
128 		/* everything after the first update is continuation */
129 		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
130 
131 		total -= to_process;
132 		data += to_process - sctx->count;
133 		sctx->count = 0;
134 		in_sg = nx_ctx->in_sg;
135 	} while (leftover >= SHA256_BLOCK_SIZE);
136 
137 	/* copy the leftover back into the state struct */
138 	if (leftover)
139 		memcpy(sctx->buf, data, leftover);
140 	sctx->count = leftover;
141 out:
142 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
143 	return rc;
144 }
145 
146 static int nx_sha256_final(struct shash_desc *desc, u8 *out)
147 {
148 	struct sha256_state *sctx = shash_desc_ctx(desc);
149 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
150 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
151 	struct nx_sg *in_sg, *out_sg;
152 	u32 max_sg_len;
153 	unsigned long irq_flags;
154 	int rc;
155 
156 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
157 
158 	max_sg_len = min_t(u32, nx_driver.of.max_sg_len, nx_ctx->ap->sglen);
159 
160 	if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
161 		/* we've hit the nx chip previously, now we're finalizing,
162 		 * so copy over the partial digest */
163 		memcpy(csbcpb->cpb.sha256.input_partial_digest,
164 		       csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
165 	}
166 
167 	/* final is represented by continuing the operation and indicating that
168 	 * this is not an intermediate operation */
169 	NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
170 
171 	csbcpb->cpb.sha256.message_bit_length += (u64)(sctx->count * 8);
172 
173 	in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buf,
174 				 sctx->count, max_sg_len);
175 	out_sg = nx_build_sg_list(nx_ctx->out_sg, out, SHA256_DIGEST_SIZE,
176 				  max_sg_len);
177 	nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
178 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
179 
180 	if (!nx_ctx->op.outlen) {
181 		rc = -EINVAL;
182 		goto out;
183 	}
184 
185 	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
186 			   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
187 	if (rc)
188 		goto out;
189 
190 	atomic_inc(&(nx_ctx->stats->sha256_ops));
191 
192 	atomic64_add(csbcpb->cpb.sha256.message_bit_length / 8,
193 		     &(nx_ctx->stats->sha256_bytes));
194 	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
195 out:
196 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
197 	return rc;
198 }
199 
200 static int nx_sha256_export(struct shash_desc *desc, void *out)
201 {
202 	struct sha256_state *sctx = shash_desc_ctx(desc);
203 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
204 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
205 	struct sha256_state *octx = out;
206 	unsigned long irq_flags;
207 
208 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
209 
210 	octx->count = sctx->count +
211 		      (csbcpb->cpb.sha256.message_bit_length / 8);
212 	memcpy(octx->buf, sctx->buf, sizeof(octx->buf));
213 
214 	/* if no data has been processed yet, we need to export SHA256's
215 	 * initial data, in case this context gets imported into a software
216 	 * context */
217 	if (csbcpb->cpb.sha256.message_bit_length)
218 		memcpy(octx->state, csbcpb->cpb.sha256.message_digest,
219 		       SHA256_DIGEST_SIZE);
220 	else {
221 		octx->state[0] = SHA256_H0;
222 		octx->state[1] = SHA256_H1;
223 		octx->state[2] = SHA256_H2;
224 		octx->state[3] = SHA256_H3;
225 		octx->state[4] = SHA256_H4;
226 		octx->state[5] = SHA256_H5;
227 		octx->state[6] = SHA256_H6;
228 		octx->state[7] = SHA256_H7;
229 	}
230 
231 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
232 	return 0;
233 }
234 
235 static int nx_sha256_import(struct shash_desc *desc, const void *in)
236 {
237 	struct sha256_state *sctx = shash_desc_ctx(desc);
238 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
239 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
240 	const struct sha256_state *ictx = in;
241 	unsigned long irq_flags;
242 
243 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
244 
245 	memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf));
246 
247 	sctx->count = ictx->count & 0x3f;
248 	csbcpb->cpb.sha256.message_bit_length = (ictx->count & ~0x3f) * 8;
249 
250 	if (csbcpb->cpb.sha256.message_bit_length) {
251 		memcpy(csbcpb->cpb.sha256.message_digest, ictx->state,
252 		       SHA256_DIGEST_SIZE);
253 
254 		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
255 		NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
256 	}
257 
258 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
259 	return 0;
260 }
261 
262 struct shash_alg nx_shash_sha256_alg = {
263 	.digestsize = SHA256_DIGEST_SIZE,
264 	.init       = nx_sha256_init,
265 	.update     = nx_sha256_update,
266 	.final      = nx_sha256_final,
267 	.export     = nx_sha256_export,
268 	.import     = nx_sha256_import,
269 	.descsize   = sizeof(struct sha256_state),
270 	.statesize  = sizeof(struct sha256_state),
271 	.base       = {
272 		.cra_name        = "sha256",
273 		.cra_driver_name = "sha256-nx",
274 		.cra_priority    = 300,
275 		.cra_flags       = CRYPTO_ALG_TYPE_SHASH,
276 		.cra_blocksize   = SHA256_BLOCK_SIZE,
277 		.cra_module      = THIS_MODULE,
278 		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
279 		.cra_init        = nx_crypto_ctx_sha_init,
280 		.cra_exit        = nx_crypto_ctx_exit,
281 	}
282 };
283