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/sha2.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 struct sha256_state_be {
20 	__be32 state[SHA256_DIGEST_SIZE / 4];
21 	u64 count;
22 	u8 buf[SHA256_BLOCK_SIZE];
23 };
24 
nx_crypto_ctx_sha256_init(struct crypto_tfm * tfm)25 static int nx_crypto_ctx_sha256_init(struct crypto_tfm *tfm)
26 {
27 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
28 	int err;
29 
30 	err = nx_crypto_ctx_sha_init(tfm);
31 	if (err)
32 		return err;
33 
34 	nx_ctx_init(nx_ctx, HCOP_FC_SHA);
35 
36 	nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];
37 
38 	NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
39 
40 	return 0;
41 }
42 
nx_sha256_init(struct shash_desc * desc)43 static int nx_sha256_init(struct shash_desc *desc) {
44 	struct sha256_state_be *sctx = shash_desc_ctx(desc);
45 
46 	memset(sctx, 0, sizeof *sctx);
47 
48 	sctx->state[0] = __cpu_to_be32(SHA256_H0);
49 	sctx->state[1] = __cpu_to_be32(SHA256_H1);
50 	sctx->state[2] = __cpu_to_be32(SHA256_H2);
51 	sctx->state[3] = __cpu_to_be32(SHA256_H3);
52 	sctx->state[4] = __cpu_to_be32(SHA256_H4);
53 	sctx->state[5] = __cpu_to_be32(SHA256_H5);
54 	sctx->state[6] = __cpu_to_be32(SHA256_H6);
55 	sctx->state[7] = __cpu_to_be32(SHA256_H7);
56 	sctx->count = 0;
57 
58 	return 0;
59 }
60 
nx_sha256_update(struct shash_desc * desc,const u8 * data,unsigned int len)61 static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
62 			    unsigned int len)
63 {
64 	struct sha256_state_be *sctx = shash_desc_ctx(desc);
65 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
66 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
67 	struct nx_sg *out_sg;
68 	u64 to_process = 0, leftover, total;
69 	unsigned long irq_flags;
70 	int rc = 0;
71 	int data_len;
72 	u32 max_sg_len;
73 	u64 buf_len = (sctx->count % SHA256_BLOCK_SIZE);
74 
75 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
76 
77 	/* 2 cases for total data len:
78 	 *  1: < SHA256_BLOCK_SIZE: copy into state, return 0
79 	 *  2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
80 	 */
81 	total = (sctx->count % SHA256_BLOCK_SIZE) + len;
82 	if (total < SHA256_BLOCK_SIZE) {
83 		memcpy(sctx->buf + buf_len, data, len);
84 		sctx->count += len;
85 		goto out;
86 	}
87 
88 	memcpy(csbcpb->cpb.sha256.message_digest, sctx->state, SHA256_DIGEST_SIZE);
89 	NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
90 	NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
91 
92 	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
93 			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
94 	max_sg_len = min_t(u64, max_sg_len,
95 			nx_ctx->ap->databytelen/NX_PAGE_SIZE);
96 
97 	data_len = SHA256_DIGEST_SIZE;
98 	out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
99 				  &data_len, max_sg_len);
100 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
101 
102 	if (data_len != SHA256_DIGEST_SIZE) {
103 		rc = -EINVAL;
104 		goto out;
105 	}
106 
107 	do {
108 		int used_sgs = 0;
109 		struct nx_sg *in_sg = nx_ctx->in_sg;
110 
111 		if (buf_len) {
112 			data_len = buf_len;
113 			in_sg = nx_build_sg_list(in_sg,
114 						 (u8 *) sctx->buf,
115 						 &data_len,
116 						 max_sg_len);
117 
118 			if (data_len != buf_len) {
119 				rc = -EINVAL;
120 				goto out;
121 			}
122 			used_sgs = in_sg - nx_ctx->in_sg;
123 		}
124 
125 		/* to_process: SHA256_BLOCK_SIZE aligned chunk to be
126 		 * processed in this iteration. This value is restricted
127 		 * by sg list limits and number of sgs we already used
128 		 * for leftover data. (see above)
129 		 * In ideal case, we could allow NX_PAGE_SIZE * max_sg_len,
130 		 * but because data may not be aligned, we need to account
131 		 * for that too. */
132 		to_process = min_t(u64, total,
133 			(max_sg_len - 1 - used_sgs) * NX_PAGE_SIZE);
134 		to_process = to_process & ~(SHA256_BLOCK_SIZE - 1);
135 
136 		data_len = to_process - buf_len;
137 		in_sg = nx_build_sg_list(in_sg, (u8 *) data,
138 					 &data_len, max_sg_len);
139 
140 		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
141 
142 		to_process = data_len + buf_len;
143 		leftover = total - to_process;
144 
145 		/*
146 		 * we've hit the nx chip previously and we're updating
147 		 * again, so copy over the partial digest.
148 		 */
149 		memcpy(csbcpb->cpb.sha256.input_partial_digest,
150 			       csbcpb->cpb.sha256.message_digest,
151 			       SHA256_DIGEST_SIZE);
152 
153 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
154 			rc = -EINVAL;
155 			goto out;
156 		}
157 
158 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
159 		if (rc)
160 			goto out;
161 
162 		atomic_inc(&(nx_ctx->stats->sha256_ops));
163 
164 		total -= to_process;
165 		data += to_process - buf_len;
166 		buf_len = 0;
167 
168 	} while (leftover >= SHA256_BLOCK_SIZE);
169 
170 	/* copy the leftover back into the state struct */
171 	if (leftover)
172 		memcpy(sctx->buf, data, leftover);
173 
174 	sctx->count += len;
175 	memcpy(sctx->state, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
176 out:
177 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
178 	return rc;
179 }
180 
nx_sha256_final(struct shash_desc * desc,u8 * out)181 static int nx_sha256_final(struct shash_desc *desc, u8 *out)
182 {
183 	struct sha256_state_be *sctx = shash_desc_ctx(desc);
184 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
185 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
186 	struct nx_sg *in_sg, *out_sg;
187 	unsigned long irq_flags;
188 	u32 max_sg_len;
189 	int rc = 0;
190 	int len;
191 
192 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
193 
194 	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
195 			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
196 	max_sg_len = min_t(u64, max_sg_len,
197 			nx_ctx->ap->databytelen/NX_PAGE_SIZE);
198 
199 	/* final is represented by continuing the operation and indicating that
200 	 * this is not an intermediate operation */
201 	if (sctx->count >= SHA256_BLOCK_SIZE) {
202 		/* we've hit the nx chip previously, now we're finalizing,
203 		 * so copy over the partial digest */
204 		memcpy(csbcpb->cpb.sha256.input_partial_digest, sctx->state, SHA256_DIGEST_SIZE);
205 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
206 		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
207 	} else {
208 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
209 		NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
210 	}
211 
212 	csbcpb->cpb.sha256.message_bit_length = (u64) (sctx->count * 8);
213 
214 	len = sctx->count & (SHA256_BLOCK_SIZE - 1);
215 	in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) sctx->buf,
216 				 &len, max_sg_len);
217 
218 	if (len != (sctx->count & (SHA256_BLOCK_SIZE - 1))) {
219 		rc = -EINVAL;
220 		goto out;
221 	}
222 
223 	len = SHA256_DIGEST_SIZE;
224 	out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len, max_sg_len);
225 
226 	if (len != SHA256_DIGEST_SIZE) {
227 		rc = -EINVAL;
228 		goto out;
229 	}
230 
231 	nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
232 	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
233 	if (!nx_ctx->op.outlen) {
234 		rc = -EINVAL;
235 		goto out;
236 	}
237 
238 	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
239 	if (rc)
240 		goto out;
241 
242 	atomic_inc(&(nx_ctx->stats->sha256_ops));
243 
244 	atomic64_add(sctx->count, &(nx_ctx->stats->sha256_bytes));
245 	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
246 out:
247 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
248 	return rc;
249 }
250 
nx_sha256_export(struct shash_desc * desc,void * out)251 static int nx_sha256_export(struct shash_desc *desc, void *out)
252 {
253 	struct sha256_state_be *sctx = shash_desc_ctx(desc);
254 
255 	memcpy(out, sctx, sizeof(*sctx));
256 
257 	return 0;
258 }
259 
nx_sha256_import(struct shash_desc * desc,const void * in)260 static int nx_sha256_import(struct shash_desc *desc, const void *in)
261 {
262 	struct sha256_state_be *sctx = shash_desc_ctx(desc);
263 
264 	memcpy(sctx, in, sizeof(*sctx));
265 
266 	return 0;
267 }
268 
269 struct shash_alg nx_shash_sha256_alg = {
270 	.digestsize = SHA256_DIGEST_SIZE,
271 	.init       = nx_sha256_init,
272 	.update     = nx_sha256_update,
273 	.final      = nx_sha256_final,
274 	.export     = nx_sha256_export,
275 	.import     = nx_sha256_import,
276 	.descsize   = sizeof(struct sha256_state_be),
277 	.statesize  = sizeof(struct sha256_state_be),
278 	.base       = {
279 		.cra_name        = "sha256",
280 		.cra_driver_name = "sha256-nx",
281 		.cra_priority    = 300,
282 		.cra_blocksize   = SHA256_BLOCK_SIZE,
283 		.cra_module      = THIS_MODULE,
284 		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
285 		.cra_init        = nx_crypto_ctx_sha256_init,
286 		.cra_exit        = nx_crypto_ctx_exit,
287 	}
288 };
289