drivers/crypto/sunxi-ss/sun4i-ss-hash.c

   1 /*
   2  * sun4i-ss-hash.c - hardware cryptographic accelerator for Allwinner A20 SoC
   3  *
   4  * Copyright (C) 2013-2015 Corentin LABBE <clabbe.montjoie@gmail.com>
   5  *
   6  * This file add support for MD5 and SHA1.
   7  *
   8  * You could find the datasheet in Documentation/arm/sunxi/README
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  */
  15 #include "sun4i-ss.h"
  16 #include <linux/scatterlist.h>
  17
  18 /* This is a totally arbitrary value */
  19 #define SS_TIMEOUT 100
  20
  21 int sun4i_hash_crainit(struct crypto_tfm *tfm)
  22 {
  23         struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
  24         struct ahash_alg *alg = __crypto_ahash_alg(tfm->__crt_alg);
  25         struct sun4i_ss_alg_template *algt;
  26
  27         memset(op, 0, sizeof(struct sun4i_tfm_ctx));
  28
  29         algt = container_of(alg, struct sun4i_ss_alg_template, alg.hash);
  30         op->ss = algt->ss;
  31
  32         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
  33                                  sizeof(struct sun4i_req_ctx));
  34         return 0;
  35 }
  36
  37 /* sun4i_hash_init: initialize request context */
  38 int sun4i_hash_init(struct ahash_request *areq)
  39 {
  40         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
  41         struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
  42         struct ahash_alg *alg = __crypto_ahash_alg(tfm->base.__crt_alg);
  43         struct sun4i_ss_alg_template *algt;
  44
  45         memset(op, 0, sizeof(struct sun4i_req_ctx));
  46
  47         algt = container_of(alg, struct sun4i_ss_alg_template, alg.hash);
  48         op->mode = algt->mode;
  49
  50         return 0;
  51 }
  52
  53 int sun4i_hash_export_md5(struct ahash_request *areq, void *out)
  54 {
  55         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
  56         struct md5_state *octx = out;
  57         int i;
  58
  59         octx->byte_count = op->byte_count + op->len;
  60
  61         memcpy(octx->block, op->buf, op->len);
  62
  63         if (op->byte_count) {
  64                 for (i = 0; i < 4; i++)
  65                         octx->hash[i] = op->hash[i];
  66         } else {
  67                 octx->hash[0] = SHA1_H0;
  68                 octx->hash[1] = SHA1_H1;
  69                 octx->hash[2] = SHA1_H2;
  70                 octx->hash[3] = SHA1_H3;
  71         }
  72
  73         return 0;
  74 }
  75
  76 int sun4i_hash_import_md5(struct ahash_request *areq, const void *in)
  77 {
  78         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
  79         const struct md5_state *ictx = in;
  80         int i;
  81
  82         sun4i_hash_init(areq);
  83
  84         op->byte_count = ictx->byte_count & ~0x3F;
  85         op->len = ictx->byte_count & 0x3F;
  86
  87         memcpy(op->buf, ictx->block, op->len);
  88
  89         for (i = 0; i < 4; i++)
  90                 op->hash[i] = ictx->hash[i];
  91
  92         return 0;
  93 }
  94
  95 int sun4i_hash_export_sha1(struct ahash_request *areq, void *out)
  96 {
  97         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
  98         struct sha1_state *octx = out;
  99         int i;
 100
 101         octx->count = op->byte_count + op->len;
 102
 103         memcpy(octx->buffer, op->buf, op->len);
 104
 105         if (op->byte_count) {
 106                 for (i = 0; i < 5; i++)
 107                         octx->state[i] = op->hash[i];
 108         } else {
 109                 octx->state[0] = SHA1_H0;
 110                 octx->state[1] = SHA1_H1;
 111                 octx->state[2] = SHA1_H2;
 112                 octx->state[3] = SHA1_H3;
 113                 octx->state[4] = SHA1_H4;
 114         }
 115
 116         return 0;
 117 }
 118
 119 int sun4i_hash_import_sha1(struct ahash_request *areq, const void *in)
 120 {
 121         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
 122         const struct sha1_state *ictx = in;
 123         int i;
 124
 125         sun4i_hash_init(areq);
 126
 127         op->byte_count = ictx->count & ~0x3F;
 128         op->len = ictx->count & 0x3F;
 129
 130         memcpy(op->buf, ictx->buffer, op->len);
 131
 132         for (i = 0; i < 5; i++)
 133                 op->hash[i] = ictx->state[i];
 134
 135         return 0;
 136 }
 137
 138 #define SS_HASH_UPDATE 1
 139 #define SS_HASH_FINAL 2
 140
 141 /*
 142  * sun4i_hash_update: update hash engine
 143  *
 144  * Could be used for both SHA1 and MD5
 145  * Write data by step of 32bits and put then in the SS.
 146  *
 147  * Since we cannot leave partial data and hash state in the engine,
 148  * we need to get the hash state at the end of this function.
 149  * We can get the hash state every 64 bytes
 150  *
 151  * So the first work is to get the number of bytes to write to SS modulo 64
 152  * The extra bytes will go to a temporary buffer op->buf storing op->len bytes
 153  *
 154  * So at the begin of update()
 155  * if op->len + areq->nbytes < 64
 156  * => all data will be written to wait buffer (op->buf) and end=0
 157  * if not, write all data from op->buf to the device and position end to
 158  * complete to 64bytes
 159  *
 160  * example 1:
 161  * update1 60o => op->len=60
 162  * update2 60o => need one more word to have 64 bytes
 163  * end=4
 164  * so write all data from op->buf and one word of SGs
 165  * write remaining data in op->buf
 166  * final state op->len=56
 167  */
 168 static int sun4i_hash(struct ahash_request *areq)
 169 {
 170         /*
 171          * i is the total bytes read from SGs, to be compared to areq->nbytes
 172          * i is important because we cannot rely on SG length since the sum of
 173          * SG->length could be greater than areq->nbytes
 174          *
 175          * end is the position when we need to stop writing to the device,
 176          * to be compared to i
 177          *
 178          * in_i: advancement in the current SG
 179          */
 180         unsigned int i = 0, end, fill, min_fill, nwait, nbw = 0, j = 0, todo;
 181         unsigned int in_i = 0;
 182         u32 spaces, rx_cnt = SS_RX_DEFAULT, bf[32] = {0}, wb = 0, v, ivmode = 0;
 183         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
 184         struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
 185         struct sun4i_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);
 186         struct sun4i_ss_ctx *ss = tfmctx->ss;
 187         struct scatterlist *in_sg = areq->src;
 188         struct sg_mapping_iter mi;
 189         int in_r, err = 0;
 190         size_t copied = 0;
 191
 192         dev_dbg(ss->dev, "%s %s bc=%llu len=%u mode=%x wl=%u h0=%0x",
 193                 __func__, crypto_tfm_alg_name(areq->base.tfm),
 194                 op->byte_count, areq->nbytes, op->mode,
 195                 op->len, op->hash[0]);
 196
 197         if (unlikely(!areq->nbytes) && !(op->flags & SS_HASH_FINAL))
 198                 return 0;
 199
 200         /* protect against overflow */
 201         if (unlikely(areq->nbytes > UINT_MAX - op->len)) {
 202                 dev_err(ss->dev, "Cannot process too large request\n");
 203                 return -EINVAL;
 204         }
 205
 206         if (op->len + areq->nbytes < 64 && !(op->flags & SS_HASH_FINAL)) {
 207                 /* linearize data to op->buf */
 208                 copied = sg_pcopy_to_buffer(areq->src, sg_nents(areq->src),
 209                                             op->buf + op->len, areq->nbytes, 0);
 210                 op->len += copied;
 211                 return 0;
 212         }
 213
 214         spin_lock_bh(&ss->slock);
 215
 216         /*
 217          * if some data have been processed before,
 218          * we need to restore the partial hash state
 219          */
 220         if (op->byte_count) {
 221                 ivmode = SS_IV_ARBITRARY;
 222                 for (i = 0; i < 5; i++)
 223                         writel(op->hash[i], ss->base + SS_IV0 + i * 4);
 224         }
 225         /* Enable the device */
 226         writel(op->mode | SS_ENABLED | ivmode, ss->base + SS_CTL);
 227
 228         if (!(op->flags & SS_HASH_UPDATE))
 229                 goto hash_final;
 230
 231         /* start of handling data */
 232         if (!(op->flags & SS_HASH_FINAL)) {
 233                 end = ((areq->nbytes + op->len) / 64) * 64 - op->len;
 234
 235                 if (end > areq->nbytes || areq->nbytes - end > 63) {
 236                         dev_err(ss->dev, "ERROR: Bound error %u %u\n",
 237                                 end, areq->nbytes);
 238                         err = -EINVAL;
 239                         goto release_ss;
 240                 }
 241         } else {
 242                 /* Since we have the flag final, we can go up to modulo 4 */
 243                 end = ((areq->nbytes + op->len) / 4) * 4 - op->len;
 244         }
 245
 246         /* TODO if SGlen % 4 and !op->len then DMA */
 247         i = 1;
 248         while (in_sg && i == 1) {
 249                 if (in_sg->length % 4)
 250                         i = 0;
 251                 in_sg = sg_next(in_sg);
 252         }
 253         if (i == 1 && !op->len && areq->nbytes)
 254                 dev_dbg(ss->dev, "We can DMA\n");
 255
 256         i = 0;
 257         sg_miter_start(&mi, areq->src, sg_nents(areq->src),
 258                        SG_MITER_FROM_SG | SG_MITER_ATOMIC);
 259         sg_miter_next(&mi);
 260         in_i = 0;
 261
 262         do {
 263                 /*
 264                  * we need to linearize in two case:
 265                  * - the buffer is already used
 266                  * - the SG does not have enough byte remaining ( < 4)
 267                  */
 268                 if (op->len || (mi.length - in_i) < 4) {
 269                         /*
 270                          * if we have entered here we have two reason to stop
 271                          * - the buffer is full
 272                          * - reach the end
 273                          */
 274                         while (op->len < 64 && i < end) {
 275                                 /* how many bytes we can read from current SG */
 276                                 in_r = min3(mi.length - in_i, end - i,
 277                                             64 - op->len);
 278                                 memcpy(op->buf + op->len, mi.addr + in_i, in_r);
 279                                 op->len += in_r;
 280                                 i += in_r;
 281                                 in_i += in_r;
 282                                 if (in_i == mi.length) {
 283                                         sg_miter_next(&mi);
 284                                         in_i = 0;
 285                                 }
 286                         }
 287                         if (op->len > 3 && !(op->len % 4)) {
 288                                 /* write buf to the device */
 289                                 writesl(ss->base + SS_RXFIFO, op->buf,
 290                                         op->len / 4);
 291                                 op->byte_count += op->len;
 292                                 op->len = 0;
 293                         }
 294                 }
 295                 if (mi.length - in_i > 3 && i < end) {
 296                         /* how many bytes we can read from current SG */
 297                         in_r = min3(mi.length - in_i, areq->nbytes - i,
 298                                     ((mi.length - in_i) / 4) * 4);
 299                         /* how many bytes we can write in the device*/
 300                         todo = min3((u32)(end - i) / 4, rx_cnt, (u32)in_r / 4);
 301                         writesl(ss->base + SS_RXFIFO, mi.addr + in_i, todo);
 302                         op->byte_count += todo * 4;
 303                         i += todo * 4;
 304                         in_i += todo * 4;
 305                         rx_cnt -= todo;
 306                         if (!rx_cnt) {
 307                                 spaces = readl(ss->base + SS_FCSR);
 308                                 rx_cnt = SS_RXFIFO_SPACES(spaces);
 309                         }
 310                         if (in_i == mi.length) {
 311                                 sg_miter_next(&mi);
 312                                 in_i = 0;
 313                         }
 314                 }
 315         } while (i < end);
 316
 317         /*
 318          * Now we have written to the device all that we can,
 319          * store the remaining bytes in op->buf
 320          */
 321         if ((areq->nbytes - i) < 64) {
 322                 while (i < areq->nbytes && in_i < mi.length && op->len < 64) {
 323                         /* how many bytes we can read from current SG */
 324                         in_r = min3(mi.length - in_i, areq->nbytes - i,
 325                                     64 - op->len);
 326                         memcpy(op->buf + op->len, mi.addr + in_i, in_r);
 327                         op->len += in_r;
 328                         i += in_r;
 329                         in_i += in_r;
 330                         if (in_i == mi.length) {
 331                                 sg_miter_next(&mi);
 332                                 in_i = 0;
 333                         }
 334                 }
 335         }
 336
 337         sg_miter_stop(&mi);
 338
 339         /*
 340          * End of data process
 341          * Now if we have the flag final go to finalize part
 342          * If not, store the partial hash
 343          */
 344         if (op->flags & SS_HASH_FINAL)
 345                 goto hash_final;
 346
 347         writel(op->mode | SS_ENABLED | SS_DATA_END, ss->base + SS_CTL);
 348         i = 0;
 349         do {
 350                 v = readl(ss->base + SS_CTL);
 351                 i++;
 352         } while (i < SS_TIMEOUT && (v & SS_DATA_END));
 353         if (unlikely(i >= SS_TIMEOUT)) {
 354                 dev_err_ratelimited(ss->dev,
 355                                     "ERROR: hash end timeout %d>%d ctl=%x len=%u\n",
 356                                     i, SS_TIMEOUT, v, areq->nbytes);
 357                 err = -EIO;
 358                 goto release_ss;
 359         }
 360
 361         /*
 362          * The datasheet isn't very clear about when to retrieve the digest. The
 363          * bit SS_DATA_END is cleared when the engine has processed the data and
 364          * when the digest is computed *but* it doesn't mean the digest is
 365          * available in the digest registers. Hence the delay to be sure we can
 366          * read it.
 367          */
 368         ndelay(1);
 369
 370         for (i = 0; i < crypto_ahash_digestsize(tfm) / 4; i++)
 371                 op->hash[i] = readl(ss->base + SS_MD0 + i * 4);
 372
 373         goto release_ss;
 374
 375 /*
 376  * hash_final: finalize hashing operation
 377  *
 378  * If we have some remaining bytes, we write them.
 379  * Then ask the SS for finalizing the hashing operation
 380  *
 381  * I do not check RX FIFO size in this function since the size is 32
 382  * after each enabling and this function neither write more than 32 words.
 383  * If we come from the update part, we cannot have more than
 384  * 3 remaining bytes to write and SS is fast enough to not care about it.
 385  */
 386
 387 hash_final:
 388
 389         /* write the remaining words of the wait buffer */
 390         if (op->len) {
 391                 nwait = op->len / 4;
 392                 if (nwait) {
 393                         writesl(ss->base + SS_RXFIFO, op->buf, nwait);
 394                         op->byte_count += 4 * nwait;
 395                 }
 396
 397                 nbw = op->len - 4 * nwait;
 398                 if (nbw) {
 399                         wb = *(u32 *)(op->buf + nwait * 4);
 400                         wb &= GENMASK((nbw * 8) - 1, 0);
 401
 402                         op->byte_count += nbw;
 403                 }
 404         }
 405
 406         /* write the remaining bytes of the nbw buffer */
 407         wb |= ((1 << 7) << (nbw * 8));
 408         bf[j++] = wb;
 409
 410         /*
 411          * number of space to pad to obtain 64o minus 8(size) minus 4 (final 1)
 412          * I take the operations from other MD5/SHA1 implementations
 413          */
 414
 415         /* last block size */
 416         fill = 64 - (op->byte_count % 64);
 417         min_fill = 2 * sizeof(u32) + (nbw ? 0 : sizeof(u32));
 418
 419         /* if we can't fill all data, jump to the next 64 block */
 420         if (fill < min_fill)
 421                 fill += 64;
 422
 423         j += (fill - min_fill) / sizeof(u32);
 424
 425         /* write the length of data */
 426         if (op->mode == SS_OP_SHA1) {
 427                 __be64 bits = cpu_to_be64(op->byte_count << 3);
 428                 bf[j++] = lower_32_bits(bits);
 429                 bf[j++] = upper_32_bits(bits);
 430         } else {
 431                 __le64 bits = op->byte_count << 3;
 432                 bf[j++] = lower_32_bits(bits);
 433                 bf[j++] = upper_32_bits(bits);
 434         }
 435         writesl(ss->base + SS_RXFIFO, bf, j);
 436
 437         /* Tell the SS to stop the hashing */
 438         writel(op->mode | SS_ENABLED | SS_DATA_END, ss->base + SS_CTL);
 439
 440         /*
 441          * Wait for SS to finish the hash.
 442          * The timeout could happen only in case of bad overclocking
 443          * or driver bug.
 444          */
 445         i = 0;
 446         do {
 447                 v = readl(ss->base + SS_CTL);
 448                 i++;
 449         } while (i < SS_TIMEOUT && (v & SS_DATA_END));
 450         if (unlikely(i >= SS_TIMEOUT)) {
 451                 dev_err_ratelimited(ss->dev,
 452                                     "ERROR: hash end timeout %d>%d ctl=%x len=%u\n",
 453                                     i, SS_TIMEOUT, v, areq->nbytes);
 454                 err = -EIO;
 455                 goto release_ss;
 456         }
 457
 458         /*
 459          * The datasheet isn't very clear about when to retrieve the digest. The
 460          * bit SS_DATA_END is cleared when the engine has processed the data and
 461          * when the digest is computed *but* it doesn't mean the digest is
 462          * available in the digest registers. Hence the delay to be sure we can
 463          * read it.
 464          */
 465         ndelay(1);
 466
 467         /* Get the hash from the device */
 468         if (op->mode == SS_OP_SHA1) {
 469                 for (i = 0; i < 5; i++) {
 470                         v = cpu_to_be32(readl(ss->base + SS_MD0 + i * 4));
 471                         memcpy(areq->result + i * 4, &v, 4);
 472                 }
 473         } else {
 474                 for (i = 0; i < 4; i++) {
 475                         v = readl(ss->base + SS_MD0 + i * 4);
 476                         memcpy(areq->result + i * 4, &v, 4);
 477                 }
 478         }
 479
 480 release_ss:
 481         writel(0, ss->base + SS_CTL);
 482         spin_unlock_bh(&ss->slock);
 483         return err;
 484 }
 485
 486 int sun4i_hash_final(struct ahash_request *areq)
 487 {
 488         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
 489
 490         op->flags = SS_HASH_FINAL;
 491         return sun4i_hash(areq);
 492 }
 493
 494 int sun4i_hash_update(struct ahash_request *areq)
 495 {
 496         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
 497
 498         op->flags = SS_HASH_UPDATE;
 499         return sun4i_hash(areq);
 500 }
 501
 502 /* sun4i_hash_finup: finalize hashing operation after an update */
 503 int sun4i_hash_finup(struct ahash_request *areq)
 504 {
 505         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
 506
 507         op->flags = SS_HASH_UPDATE | SS_HASH_FINAL;
 508         return sun4i_hash(areq);
 509 }
 510
 511 /* combo of init/update/final functions */
 512 int sun4i_hash_digest(struct ahash_request *areq)
 513 {
 514         int err;
 515         struct sun4i_req_ctx *op = ahash_request_ctx(areq);
 516
 517         err = sun4i_hash_init(areq);
 518         if (err)
 519                 return err;
 520
 521         op->flags = SS_HASH_UPDATE | SS_HASH_FINAL;
 522         return sun4i_hash(areq);
 523 }