xref: /openbmc/linux/drivers/crypto/nx/nx-sha256.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /**
3  * SHA-256 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/internal/hash.h>
11 #include <crypto/sha.h>
12 #include <linux/module.h>
13 #include <asm/vio.h>
14 #include <asm/byteorder.h>
15 
16 #include "nx_csbcpb.h"
17 #include "nx.h"
18 
19 
20 static int nx_crypto_ctx_sha256_init(struct crypto_tfm *tfm)
21 {
22 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
23 	int err;
24 
25 	err = nx_crypto_ctx_sha_init(tfm);
26 	if (err)
27 		return err;
28 
29 	nx_ctx_init(nx_ctx, HCOP_FC_SHA);
30 
31 	nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];
32 
33 	NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
34 
35 	return 0;
36 }
37 
38 static int nx_sha256_init(struct shash_desc *desc) {
39 	struct sha256_state *sctx = shash_desc_ctx(desc);
40 
41 	memset(sctx, 0, sizeof *sctx);
42 
43 	sctx->state[0] = __cpu_to_be32(SHA256_H0);
44 	sctx->state[1] = __cpu_to_be32(SHA256_H1);
45 	sctx->state[2] = __cpu_to_be32(SHA256_H2);
46 	sctx->state[3] = __cpu_to_be32(SHA256_H3);
47 	sctx->state[4] = __cpu_to_be32(SHA256_H4);
48 	sctx->state[5] = __cpu_to_be32(SHA256_H5);
49 	sctx->state[6] = __cpu_to_be32(SHA256_H6);
50 	sctx->state[7] = __cpu_to_be32(SHA256_H7);
51 	sctx->count = 0;
52 
53 	return 0;
54 }
55 
56 static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
57 			    unsigned int len)
58 {
59 	struct sha256_state *sctx = shash_desc_ctx(desc);
60 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
61 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
62 	struct nx_sg *out_sg;
63 	u64 to_process = 0, leftover, total;
64 	unsigned long irq_flags;
65 	int rc = 0;
66 	int data_len;
67 	u32 max_sg_len;
68 	u64 buf_len = (sctx->count % SHA256_BLOCK_SIZE);
69 
70 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
71 
72 	/* 2 cases for total data len:
73 	 *  1: < SHA256_BLOCK_SIZE: copy into state, return 0
74 	 *  2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
75 	 */
76 	total = (sctx->count % SHA256_BLOCK_SIZE) + len;
77 	if (total < SHA256_BLOCK_SIZE) {
78 		memcpy(sctx->buf + buf_len, data, len);
79 		sctx->count += len;
80 		goto out;
81 	}
82 
83 	memcpy(csbcpb->cpb.sha256.message_digest, sctx->state, SHA256_DIGEST_SIZE);
84 	NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
85 	NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
86 
87 	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
88 			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
89 	max_sg_len = min_t(u64, max_sg_len,
90 			nx_ctx->ap->databytelen/NX_PAGE_SIZE);
91 
92 	data_len = SHA256_DIGEST_SIZE;
93 	out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
94 				  &data_len, max_sg_len);
95 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
96 
97 	if (data_len != SHA256_DIGEST_SIZE) {
98 		rc = -EINVAL;
99 		goto out;
100 	}
101 
102 	do {
103 		int used_sgs = 0;
104 		struct nx_sg *in_sg = nx_ctx->in_sg;
105 
106 		if (buf_len) {
107 			data_len = buf_len;
108 			in_sg = nx_build_sg_list(in_sg,
109 						 (u8 *) sctx->buf,
110 						 &data_len,
111 						 max_sg_len);
112 
113 			if (data_len != buf_len) {
114 				rc = -EINVAL;
115 				goto out;
116 			}
117 			used_sgs = in_sg - nx_ctx->in_sg;
118 		}
119 
120 		/* to_process: SHA256_BLOCK_SIZE aligned chunk to be
121 		 * processed in this iteration. This value is restricted
122 		 * by sg list limits and number of sgs we already used
123 		 * for leftover data. (see above)
124 		 * In ideal case, we could allow NX_PAGE_SIZE * max_sg_len,
125 		 * but because data may not be aligned, we need to account
126 		 * for that too. */
127 		to_process = min_t(u64, total,
128 			(max_sg_len - 1 - used_sgs) * NX_PAGE_SIZE);
129 		to_process = to_process & ~(SHA256_BLOCK_SIZE - 1);
130 
131 		data_len = to_process - buf_len;
132 		in_sg = nx_build_sg_list(in_sg, (u8 *) data,
133 					 &data_len, max_sg_len);
134 
135 		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
136 
137 		to_process = data_len + buf_len;
138 		leftover = total - to_process;
139 
140 		/*
141 		 * we've hit the nx chip previously and we're updating
142 		 * again, so copy over the partial digest.
143 		 */
144 		memcpy(csbcpb->cpb.sha256.input_partial_digest,
145 			       csbcpb->cpb.sha256.message_digest,
146 			       SHA256_DIGEST_SIZE);
147 
148 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
149 			rc = -EINVAL;
150 			goto out;
151 		}
152 
153 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
154 		if (rc)
155 			goto out;
156 
157 		atomic_inc(&(nx_ctx->stats->sha256_ops));
158 
159 		total -= to_process;
160 		data += to_process - buf_len;
161 		buf_len = 0;
162 
163 	} while (leftover >= SHA256_BLOCK_SIZE);
164 
165 	/* copy the leftover back into the state struct */
166 	if (leftover)
167 		memcpy(sctx->buf, data, leftover);
168 
169 	sctx->count += len;
170 	memcpy(sctx->state, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
171 out:
172 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
173 	return rc;
174 }
175 
176 static int nx_sha256_final(struct shash_desc *desc, u8 *out)
177 {
178 	struct sha256_state *sctx = shash_desc_ctx(desc);
179 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
180 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
181 	struct nx_sg *in_sg, *out_sg;
182 	unsigned long irq_flags;
183 	u32 max_sg_len;
184 	int rc = 0;
185 	int len;
186 
187 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
188 
189 	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
190 			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
191 	max_sg_len = min_t(u64, max_sg_len,
192 			nx_ctx->ap->databytelen/NX_PAGE_SIZE);
193 
194 	/* final is represented by continuing the operation and indicating that
195 	 * this is not an intermediate operation */
196 	if (sctx->count >= SHA256_BLOCK_SIZE) {
197 		/* we've hit the nx chip previously, now we're finalizing,
198 		 * so copy over the partial digest */
199 		memcpy(csbcpb->cpb.sha256.input_partial_digest, sctx->state, SHA256_DIGEST_SIZE);
200 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
201 		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
202 	} else {
203 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
204 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
205 	}
206 
207 	csbcpb->cpb.sha256.message_bit_length = (u64) (sctx->count * 8);
208 
209 	len = sctx->count & (SHA256_BLOCK_SIZE - 1);
210 	in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) sctx->buf,
211 				 &len, max_sg_len);
212 
213 	if (len != (sctx->count & (SHA256_BLOCK_SIZE - 1))) {
214 		rc = -EINVAL;
215 		goto out;
216 	}
217 
218 	len = SHA256_DIGEST_SIZE;
219 	out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len, max_sg_len);
220 
221 	if (len != SHA256_DIGEST_SIZE) {
222 		rc = -EINVAL;
223 		goto out;
224 	}
225 
226 	nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
227 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
228 	if (!nx_ctx->op.outlen) {
229 		rc = -EINVAL;
230 		goto out;
231 	}
232 
233 	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
234 	if (rc)
235 		goto out;
236 
237 	atomic_inc(&(nx_ctx->stats->sha256_ops));
238 
239 	atomic64_add(sctx->count, &(nx_ctx->stats->sha256_bytes));
240 	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
241 out:
242 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
243 	return rc;
244 }
245 
246 static int nx_sha256_export(struct shash_desc *desc, void *out)
247 {
248 	struct sha256_state *sctx = shash_desc_ctx(desc);
249 
250 	memcpy(out, sctx, sizeof(*sctx));
251 
252 	return 0;
253 }
254 
255 static int nx_sha256_import(struct shash_desc *desc, const void *in)
256 {
257 	struct sha256_state *sctx = shash_desc_ctx(desc);
258 
259 	memcpy(sctx, in, sizeof(*sctx));
260 
261 	return 0;
262 }
263 
264 struct shash_alg nx_shash_sha256_alg = {
265 	.digestsize = SHA256_DIGEST_SIZE,
266 	.init       = nx_sha256_init,
267 	.update     = nx_sha256_update,
268 	.final      = nx_sha256_final,
269 	.export     = nx_sha256_export,
270 	.import     = nx_sha256_import,
271 	.descsize   = sizeof(struct sha256_state),
272 	.statesize  = sizeof(struct sha256_state),
273 	.base       = {
274 		.cra_name        = "sha256",
275 		.cra_driver_name = "sha256-nx",
276 		.cra_priority    = 300,
277 		.cra_blocksize   = SHA256_BLOCK_SIZE,
278 		.cra_module      = THIS_MODULE,
279 		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
280 		.cra_init        = nx_crypto_ctx_sha256_init,
281 		.cra_exit        = nx_crypto_ctx_exit,
282 	}
283 };
284