1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * sl3516-ce-cipher.c - hardware cryptographic offloader for Storlink SL3516 SoC
4 *
5 * Copyright (C) 2021 Corentin LABBE <clabbe@baylibre.com>
6 *
7 * This file adds support for AES cipher with 128,192,256 bits keysize in
8 * ECB mode.
9 */
10
11 #include <linux/crypto.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 #include <linux/pm_runtime.h>
16 #include <crypto/scatterwalk.h>
17 #include <crypto/internal/skcipher.h>
18 #include "sl3516-ce.h"
19
20 /* sl3516_ce_need_fallback - check if a request can be handled by the CE */
sl3516_ce_need_fallback(struct skcipher_request * areq)21 static bool sl3516_ce_need_fallback(struct skcipher_request *areq)
22 {
23 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
24 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
25 struct sl3516_ce_dev *ce = op->ce;
26 struct scatterlist *in_sg;
27 struct scatterlist *out_sg;
28 struct scatterlist *sg;
29
30 if (areq->cryptlen == 0 || areq->cryptlen % 16) {
31 ce->fallback_mod16++;
32 return true;
33 }
34
35 /*
36 * check if we have enough descriptors for TX
37 * Note: TX need one control desc for each SG
38 */
39 if (sg_nents(areq->src) > MAXDESC / 2) {
40 ce->fallback_sg_count_tx++;
41 return true;
42 }
43 /* check if we have enough descriptors for RX */
44 if (sg_nents(areq->dst) > MAXDESC) {
45 ce->fallback_sg_count_rx++;
46 return true;
47 }
48
49 sg = areq->src;
50 while (sg) {
51 if ((sg->length % 16) != 0) {
52 ce->fallback_mod16++;
53 return true;
54 }
55 if ((sg_dma_len(sg) % 16) != 0) {
56 ce->fallback_mod16++;
57 return true;
58 }
59 if (!IS_ALIGNED(sg->offset, 16)) {
60 ce->fallback_align16++;
61 return true;
62 }
63 sg = sg_next(sg);
64 }
65 sg = areq->dst;
66 while (sg) {
67 if ((sg->length % 16) != 0) {
68 ce->fallback_mod16++;
69 return true;
70 }
71 if ((sg_dma_len(sg) % 16) != 0) {
72 ce->fallback_mod16++;
73 return true;
74 }
75 if (!IS_ALIGNED(sg->offset, 16)) {
76 ce->fallback_align16++;
77 return true;
78 }
79 sg = sg_next(sg);
80 }
81
82 /* need same numbers of SG (with same length) for source and destination */
83 in_sg = areq->src;
84 out_sg = areq->dst;
85 while (in_sg && out_sg) {
86 if (in_sg->length != out_sg->length) {
87 ce->fallback_not_same_len++;
88 return true;
89 }
90 in_sg = sg_next(in_sg);
91 out_sg = sg_next(out_sg);
92 }
93 if (in_sg || out_sg)
94 return true;
95
96 return false;
97 }
98
sl3516_ce_cipher_fallback(struct skcipher_request * areq)99 static int sl3516_ce_cipher_fallback(struct skcipher_request *areq)
100 {
101 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
102 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
103 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
104 struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
105 struct sl3516_ce_alg_template *algt;
106 int err;
107
108 algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
109 algt->stat_fb++;
110
111 skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm);
112 skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags,
113 areq->base.complete, areq->base.data);
114 skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst,
115 areq->cryptlen, areq->iv);
116 if (rctx->op_dir == CE_DECRYPTION)
117 err = crypto_skcipher_decrypt(&rctx->fallback_req);
118 else
119 err = crypto_skcipher_encrypt(&rctx->fallback_req);
120 return err;
121 }
122
sl3516_ce_cipher(struct skcipher_request * areq)123 static int sl3516_ce_cipher(struct skcipher_request *areq)
124 {
125 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
126 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
127 struct sl3516_ce_dev *ce = op->ce;
128 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
129 struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
130 struct sl3516_ce_alg_template *algt;
131 struct scatterlist *sg;
132 unsigned int todo, len;
133 struct pkt_control_ecb *ecb;
134 int nr_sgs = 0;
135 int nr_sgd = 0;
136 int err = 0;
137 int i;
138
139 algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
140
141 dev_dbg(ce->dev, "%s %s %u %x IV(%p %u) key=%u\n", __func__,
142 crypto_tfm_alg_name(areq->base.tfm),
143 areq->cryptlen,
144 rctx->op_dir, areq->iv, crypto_skcipher_ivsize(tfm),
145 op->keylen);
146
147 algt->stat_req++;
148
149 if (areq->src == areq->dst) {
150 nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
151 DMA_BIDIRECTIONAL);
152 if (nr_sgs <= 0 || nr_sgs > MAXDESC / 2) {
153 dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
154 err = -EINVAL;
155 goto theend;
156 }
157 nr_sgd = nr_sgs;
158 } else {
159 nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
160 DMA_TO_DEVICE);
161 if (nr_sgs <= 0 || nr_sgs > MAXDESC / 2) {
162 dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
163 err = -EINVAL;
164 goto theend;
165 }
166 nr_sgd = dma_map_sg(ce->dev, areq->dst, sg_nents(areq->dst),
167 DMA_FROM_DEVICE);
168 if (nr_sgd <= 0 || nr_sgd > MAXDESC) {
169 dev_err(ce->dev, "Invalid sg number %d\n", nr_sgd);
170 err = -EINVAL;
171 goto theend_sgs;
172 }
173 }
174
175 len = areq->cryptlen;
176 i = 0;
177 sg = areq->src;
178 while (i < nr_sgs && sg && len) {
179 if (sg_dma_len(sg) == 0)
180 goto sgs_next;
181 rctx->t_src[i].addr = sg_dma_address(sg);
182 todo = min(len, sg_dma_len(sg));
183 rctx->t_src[i].len = todo;
184 dev_dbg(ce->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__,
185 areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo);
186 len -= todo;
187 i++;
188 sgs_next:
189 sg = sg_next(sg);
190 }
191 if (len > 0) {
192 dev_err(ce->dev, "remaining len %d/%u nr_sgs=%d\n", len, areq->cryptlen, nr_sgs);
193 err = -EINVAL;
194 goto theend_sgs;
195 }
196
197 len = areq->cryptlen;
198 i = 0;
199 sg = areq->dst;
200 while (i < nr_sgd && sg && len) {
201 if (sg_dma_len(sg) == 0)
202 goto sgd_next;
203 rctx->t_dst[i].addr = sg_dma_address(sg);
204 todo = min(len, sg_dma_len(sg));
205 rctx->t_dst[i].len = todo;
206 dev_dbg(ce->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__,
207 areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo);
208 len -= todo;
209 i++;
210
211 sgd_next:
212 sg = sg_next(sg);
213 }
214 if (len > 0) {
215 dev_err(ce->dev, "remaining len %d\n", len);
216 err = -EINVAL;
217 goto theend_sgs;
218 }
219
220 switch (algt->mode) {
221 case ECB_AES:
222 rctx->pctrllen = sizeof(struct pkt_control_ecb);
223 ecb = (struct pkt_control_ecb *)ce->pctrl;
224
225 rctx->tqflag = TQ0_TYPE_CTRL;
226 rctx->tqflag |= TQ1_CIPHER;
227 ecb->control.op_mode = rctx->op_dir;
228 ecb->control.cipher_algorithm = ECB_AES;
229 ecb->cipher.header_len = 0;
230 ecb->cipher.algorithm_len = areq->cryptlen;
231 cpu_to_be32_array((__be32 *)ecb->key, (u32 *)op->key, op->keylen / 4);
232 rctx->h = &ecb->cipher;
233
234 rctx->tqflag |= TQ4_KEY0;
235 rctx->tqflag |= TQ5_KEY4;
236 rctx->tqflag |= TQ6_KEY6;
237 ecb->control.aesnk = op->keylen / 4;
238 break;
239 }
240
241 rctx->nr_sgs = nr_sgs;
242 rctx->nr_sgd = nr_sgd;
243 err = sl3516_ce_run_task(ce, rctx, crypto_tfm_alg_name(areq->base.tfm));
244
245 theend_sgs:
246 if (areq->src == areq->dst) {
247 dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
248 DMA_BIDIRECTIONAL);
249 } else {
250 dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
251 DMA_TO_DEVICE);
252 dma_unmap_sg(ce->dev, areq->dst, sg_nents(areq->dst),
253 DMA_FROM_DEVICE);
254 }
255
256 theend:
257
258 return err;
259 }
260
sl3516_ce_handle_cipher_request(struct crypto_engine * engine,void * areq)261 static int sl3516_ce_handle_cipher_request(struct crypto_engine *engine, void *areq)
262 {
263 int err;
264 struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);
265
266 err = sl3516_ce_cipher(breq);
267 local_bh_disable();
268 crypto_finalize_skcipher_request(engine, breq, err);
269 local_bh_enable();
270
271 return 0;
272 }
273
sl3516_ce_skdecrypt(struct skcipher_request * areq)274 int sl3516_ce_skdecrypt(struct skcipher_request *areq)
275 {
276 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
277 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
278 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
279 struct crypto_engine *engine;
280
281 memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx));
282 rctx->op_dir = CE_DECRYPTION;
283
284 if (sl3516_ce_need_fallback(areq))
285 return sl3516_ce_cipher_fallback(areq);
286
287 engine = op->ce->engine;
288
289 return crypto_transfer_skcipher_request_to_engine(engine, areq);
290 }
291
sl3516_ce_skencrypt(struct skcipher_request * areq)292 int sl3516_ce_skencrypt(struct skcipher_request *areq)
293 {
294 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
295 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
296 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
297 struct crypto_engine *engine;
298
299 memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx));
300 rctx->op_dir = CE_ENCRYPTION;
301
302 if (sl3516_ce_need_fallback(areq))
303 return sl3516_ce_cipher_fallback(areq);
304
305 engine = op->ce->engine;
306
307 return crypto_transfer_skcipher_request_to_engine(engine, areq);
308 }
309
sl3516_ce_cipher_init(struct crypto_tfm * tfm)310 int sl3516_ce_cipher_init(struct crypto_tfm *tfm)
311 {
312 struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
313 struct sl3516_ce_alg_template *algt;
314 const char *name = crypto_tfm_alg_name(tfm);
315 struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);
316 struct skcipher_alg *alg = crypto_skcipher_alg(sktfm);
317 int err;
318
319 memset(op, 0, sizeof(struct sl3516_ce_cipher_tfm_ctx));
320
321 algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
322 op->ce = algt->ce;
323
324 op->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
325 if (IS_ERR(op->fallback_tfm)) {
326 dev_err(op->ce->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
327 name, PTR_ERR(op->fallback_tfm));
328 return PTR_ERR(op->fallback_tfm);
329 }
330
331 sktfm->reqsize = sizeof(struct sl3516_ce_cipher_req_ctx) +
332 crypto_skcipher_reqsize(op->fallback_tfm);
333
334 dev_info(op->ce->dev, "Fallback for %s is %s\n",
335 crypto_tfm_alg_driver_name(&sktfm->base),
336 crypto_tfm_alg_driver_name(crypto_skcipher_tfm(op->fallback_tfm)));
337
338 op->enginectx.op.do_one_request = sl3516_ce_handle_cipher_request;
339 op->enginectx.op.prepare_request = NULL;
340 op->enginectx.op.unprepare_request = NULL;
341
342 err = pm_runtime_get_sync(op->ce->dev);
343 if (err < 0)
344 goto error_pm;
345
346 return 0;
347 error_pm:
348 pm_runtime_put_noidle(op->ce->dev);
349 crypto_free_skcipher(op->fallback_tfm);
350 return err;
351 }
352
sl3516_ce_cipher_exit(struct crypto_tfm * tfm)353 void sl3516_ce_cipher_exit(struct crypto_tfm *tfm)
354 {
355 struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
356
357 kfree_sensitive(op->key);
358 crypto_free_skcipher(op->fallback_tfm);
359 pm_runtime_put_sync_suspend(op->ce->dev);
360 }
361
sl3516_ce_aes_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)362 int sl3516_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
363 unsigned int keylen)
364 {
365 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
366 struct sl3516_ce_dev *ce = op->ce;
367
368 switch (keylen) {
369 case 128 / 8:
370 break;
371 case 192 / 8:
372 break;
373 case 256 / 8:
374 break;
375 default:
376 dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen);
377 return -EINVAL;
378 }
379 kfree_sensitive(op->key);
380 op->keylen = keylen;
381 op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
382 if (!op->key)
383 return -ENOMEM;
384
385 crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
386 crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
387
388 return crypto_skcipher_setkey(op->fallback_tfm, key, keylen);
389 }
390
