target/linux/generic-2.6/patches-2.6.31/052-pcomp_lzma_support.patch

   1 --- /dev/null
   2 +++ b/crypto/unlzma.c
   3 @@ -0,0 +1,775 @@
   4 +/*
   5 + * LZMA uncompresion module for pcomp
   6 + * Copyright (C) 2009  Felix Fietkau <nbd@openwrt.org>
   7 + *
   8 + * Based on:
   9 + *  Initial Linux kernel adaptation
  10 + *  Copyright (C) 2006  Alain < alain@knaff.lu >
  11 + *
  12 + *  Based on small lzma deflate implementation/Small range coder
  13 + *  implementation for lzma.
  14 + *  Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
  15 + *
  16 + *  Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
  17 + *  Copyright (C) 1999-2005  Igor Pavlov
  18 + *
  19 + * This program is free software; you can redistribute it and/or modify it
  20 + * under the terms of the GNU General Public License version 2 as published
  21 + * by the Free Software Foundation.
  22 + *
  23 + * FIXME: the current implementation assumes that the caller will
  24 + * not free any output buffers until the whole decompression has been
  25 + * completed. This is necessary, because LZMA looks back at old output
  26 + * instead of doing a separate dictionary allocation, which saves RAM.
  27 + */
  28 +
  29 +#include <linux/init.h>
  30 +#include <linux/module.h>
  31 +#include <linux/vmalloc.h>
  32 +#include <linux/interrupt.h>
  33 +#include <linux/mm.h>
  34 +#include <linux/net.h>
  35 +#include <linux/slab.h>
  36 +#include <linux/kthread.h>
  37 +
  38 +#include <crypto/internal/compress.h>
  39 +#include <net/netlink.h>
  40 +#include "unlzma.h"
  41 +
  42 +static int instance = 0;
  43 +
  44 +struct unlzma_buffer {
  45 +       int offset;
  46 +       int size;
  47 +       u8 *ptr;
  48 +};
  49 +
  50 +struct unlzma_ctx {
  51 +       struct task_struct *thread;
  52 +       wait_queue_head_t next_req;
  53 +       wait_queue_head_t req_done;
  54 +       struct mutex mutex;
  55 +       bool waiting;
  56 +       bool active;
  57 +       bool cancel;
  58 +
  59 +       const u8 *next_in;
  60 +       int avail_in;
  61 +
  62 +       u8 *next_out;
  63 +       int avail_out;
  64 +
  65 +       /* reader state */
  66 +       u32 code;
  67 +       u32 range;
  68 +       u32 bound;
  69 +
  70 +       /* writer state */
  71 +       u8 previous_byte;
  72 +       ssize_t pos;
  73 +       int buf_full;
  74 +       int n_buffers;
  75 +       int buffers_max;
  76 +       struct unlzma_buffer *buffers;
  77 +
  78 +       /* cstate */
  79 +       int state;
  80 +       u32 rep0, rep1, rep2, rep3;
  81 +
  82 +       u32 dict_size;
  83 +
  84 +       void *workspace;
  85 +       int workspace_size;
  86 +};
  87 +
  88 +static inline bool
  89 +unlzma_should_stop(struct unlzma_ctx *ctx)
  90 +{
  91 +       return unlikely(kthread_should_stop() || ctx->cancel);
  92 +}
  93 +
  94 +static void
  95 +get_buffer(struct unlzma_ctx *ctx)
  96 +{
  97 +       struct unlzma_buffer *bh;
  98 +
  99 +       BUG_ON(ctx->n_buffers >= ctx->buffers_max);
 100 +       bh = &ctx->buffers[ctx->n_buffers++];
 101 +       bh->ptr = ctx->next_out;
 102 +       bh->offset = ctx->pos;
 103 +       bh->size = ctx->avail_out;
 104 +       ctx->buf_full = 0;
 105 +}
 106 +
 107 +static void
 108 +unlzma_request_buffer(struct unlzma_ctx *ctx, int *avail)
 109 +{
 110 +       do {
 111 +               ctx->waiting = true;
 112 +               mutex_unlock(&ctx->mutex);
 113 +               wake_up(&ctx->req_done);
 114 +               if (wait_event_interruptible(ctx->next_req,
 115 +                       unlzma_should_stop(ctx) || (*avail > 0)))
 116 +                       schedule();
 117 +               mutex_lock(&ctx->mutex);
 118 +       } while (*avail <= 0 && !unlzma_should_stop(ctx));
 119 +
 120 +       if (!unlzma_should_stop(ctx) && ctx->buf_full)
 121 +               get_buffer(ctx);
 122 +}
 123 +
 124 +static u8
 125 +rc_read(struct unlzma_ctx *ctx)
 126 +{
 127 +       if (unlikely(ctx->avail_in <= 0))
 128 +               unlzma_request_buffer(ctx, &ctx->avail_in);
 129 +
 130 +       if (unlzma_should_stop(ctx))
 131 +               return 0;
 132 +
 133 +       ctx->avail_in--;
 134 +       return *(ctx->next_in++);
 135 +}
 136 +
 137 +
 138 +static inline void
 139 +rc_get_code(struct unlzma_ctx *ctx)
 140 +{
 141 +       ctx->code = (ctx->code << 8) | rc_read(ctx);
 142 +}
 143 +
 144 +static void
 145 +rc_normalize(struct unlzma_ctx *ctx)
 146 +{
 147 +       if (ctx->range < (1 << RC_TOP_BITS)) {
 148 +               ctx->range <<= 8;
 149 +               rc_get_code(ctx);
 150 +       }
 151 +}
 152 +
 153 +static int
 154 +rc_is_bit_0(struct unlzma_ctx *ctx, u16 *p)
 155 +{
 156 +       rc_normalize(ctx);
 157 +       ctx->bound = *p * (ctx->range >> RC_MODEL_TOTAL_BITS);
 158 +       return ctx->code < ctx->bound;
 159 +}
 160 +
 161 +static void
 162 +rc_update_bit_0(struct unlzma_ctx *ctx, u16 *p)
 163 +{
 164 +       ctx->range = ctx->bound;
 165 +       *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
 166 +}
 167 +
 168 +static void
 169 +rc_update_bit_1(struct unlzma_ctx *ctx, u16 *p)
 170 +{
 171 +       ctx->range -= ctx->bound;
 172 +       ctx->code -= ctx->bound;
 173 +       *p -= *p >> RC_MOVE_BITS;
 174 +}
 175 +
 176 +static bool
 177 +rc_get_bit(struct unlzma_ctx *ctx, u16 *p, int *symbol)
 178 +{
 179 +       if (rc_is_bit_0(ctx, p)) {
 180 +               rc_update_bit_0(ctx, p);
 181 +               *symbol *= 2;
 182 +               return 0;
 183 +       } else {
 184 +               rc_update_bit_1(ctx, p);
 185 +               *symbol = *symbol * 2 + 1;
 186 +               return 1;
 187 +       }
 188 +}
 189 +
 190 +static int
 191 +rc_direct_bit(struct unlzma_ctx *ctx)
 192 +{
 193 +       rc_normalize(ctx);
 194 +       ctx->range >>= 1;
 195 +       if (ctx->code >= ctx->range) {
 196 +               ctx->code -= ctx->range;
 197 +               return 1;
 198 +       }
 199 +       return 0;
 200 +}
 201 +
 202 +static void
 203 +rc_bit_tree_decode(struct unlzma_ctx *ctx, u16 *p, int num_levels, int *symbol)
 204 +{
 205 +       int i = num_levels;
 206 +
 207 +       *symbol = 1;
 208 +       while (i--)
 209 +               rc_get_bit(ctx, p + *symbol, symbol);
 210 +       *symbol -= 1 << num_levels;
 211 +}
 212 +
 213 +static u8
 214 +peek_old_byte(struct unlzma_ctx *ctx, u32 offs)
 215 +{
 216 +       struct unlzma_buffer *bh = &ctx->buffers[ctx->n_buffers - 1];
 217 +       int i = ctx->n_buffers;
 218 +       u32 pos;
 219 +
 220 +       if (!ctx->n_buffers) {
 221 +               printk(KERN_ERR "unlzma/%s: no buffer\n", __func__);
 222 +               goto error;
 223 +       }
 224 +
 225 +       pos = ctx->pos - offs;
 226 +       if (unlikely(pos >= ctx->dict_size))
 227 +               pos = ~pos & (ctx->dict_size - 1);
 228 +
 229 +       while (bh->offset > pos) {
 230 +               bh--;
 231 +               i--;
 232 +               if (!i) {
 233 +                       printk(KERN_ERR "unlzma/%s: position %d out of range\n", __func__, pos);
 234 +                       goto error;
 235 +               }
 236 +       }
 237 +
 238 +       pos -= bh->offset;
 239 +       if (pos >= bh->size) {
 240 +               printk(KERN_ERR "unlzma/%s: position %d out of range\n", __func__, pos);
 241 +               goto error;
 242 +       }
 243 +
 244 +       return bh->ptr[pos];
 245 +
 246 +error:
 247 +       ctx->cancel = true;
 248 +       return 0;
 249 +}
 250 +
 251 +static void
 252 +write_byte(struct unlzma_ctx *ctx, u8 byte)
 253 +{
 254 +       if (unlikely(ctx->avail_out <= 0)) {
 255 +               unlzma_request_buffer(ctx, &ctx->avail_out);
 256 +       }
 257 +
 258 +       if (!ctx->avail_out)
 259 +               return;
 260 +
 261 +       ctx->previous_byte = byte;
 262 +       *(ctx->next_out++) = byte;
 263 +       ctx->avail_out--;
 264 +       if (ctx->avail_out == 0)
 265 +               ctx->buf_full = 1;
 266 +       ctx->pos++;
 267 +}
 268 +
 269 +
 270 +static inline void
 271 +copy_byte(struct unlzma_ctx *ctx, u32 offs)
 272 +{
 273 +       write_byte(ctx, peek_old_byte(ctx, offs));
 274 +}
 275 +
 276 +static void
 277 +copy_bytes(struct unlzma_ctx *ctx, u32 rep0, int len)
 278 +{
 279 +       do {
 280 +               copy_byte(ctx, rep0);
 281 +               len--;
 282 +               if (unlzma_should_stop(ctx))
 283 +                       break;
 284 +       } while (len != 0);
 285 +}
 286 +
 287 +static void
 288 +process_bit0(struct unlzma_ctx *ctx, u16 *p, int pos_state, u16 *prob,
 289 +             int lc, u32 literal_pos_mask)
 290 +{
 291 +       int mi = 1;
 292 +       rc_update_bit_0(ctx, prob);
 293 +       prob = (p + LZMA_LITERAL +
 294 +               (LZMA_LIT_SIZE
 295 +                * (((ctx->pos & literal_pos_mask) << lc)
 296 +                   + (ctx->previous_byte >> (8 - lc))))
 297 +               );
 298 +
 299 +       if (ctx->state >= LZMA_NUM_LIT_STATES) {
 300 +               int match_byte = peek_old_byte(ctx, ctx->rep0);
 301 +               do {
 302 +                       u16 bit;
 303 +                       u16 *prob_lit;
 304 +
 305 +                       match_byte <<= 1;
 306 +                       bit = match_byte & 0x100;
 307 +                       prob_lit = prob + 0x100 + bit + mi;
 308 +                       if (rc_get_bit(ctx, prob_lit, &mi) != !!bit)
 309 +                               break;
 310 +               } while (mi < 0x100);
 311 +       }
 312 +       while (mi < 0x100) {
 313 +               u16 *prob_lit = prob + mi;
 314 +               rc_get_bit(ctx, prob_lit, &mi);
 315 +       }
 316 +       write_byte(ctx, mi);
 317 +       if (ctx->state < 4)
 318 +               ctx->state = 0;
 319 +       else if (ctx->state < 10)
 320 +               ctx->state -= 3;
 321 +       else
 322 +               ctx->state -= 6;
 323 +}
 324 +
 325 +static void
 326 +process_bit1(struct unlzma_ctx *ctx, u16 *p, int pos_state, u16 *prob)
 327 +{
 328 +       int offset;
 329 +       u16 *prob_len;
 330 +       int num_bits;
 331 +       int len;
 332 +
 333 +       rc_update_bit_1(ctx, prob);
 334 +       prob = p + LZMA_IS_REP + ctx->state;
 335 +       if (rc_is_bit_0(ctx, prob)) {
 336 +               rc_update_bit_0(ctx, prob);
 337 +               ctx->rep3 = ctx->rep2;
 338 +               ctx->rep2 = ctx->rep1;
 339 +               ctx->rep1 = ctx->rep0;
 340 +               ctx->state = ctx->state < LZMA_NUM_LIT_STATES ? 0 : 3;
 341 +               prob = p + LZMA_LEN_CODER;
 342 +       } else {
 343 +               rc_update_bit_1(ctx, prob);
 344 +               prob = p + LZMA_IS_REP_G0 + ctx->state;
 345 +               if (rc_is_bit_0(ctx, prob)) {
 346 +                       rc_update_bit_0(ctx, prob);
 347 +                       prob = (p + LZMA_IS_REP_0_LONG
 348 +                               + (ctx->state <<
 349 +                                  LZMA_NUM_POS_BITS_MAX) +
 350 +                               pos_state);
 351 +                       if (rc_is_bit_0(ctx, prob)) {
 352 +                               rc_update_bit_0(ctx, prob);
 353 +
 354 +                               ctx->state = ctx->state < LZMA_NUM_LIT_STATES ?
 355 +                                       9 : 11;
 356 +                               copy_byte(ctx, ctx->rep0);
 357 +                               return;
 358 +                       } else {
 359 +                               rc_update_bit_1(ctx, prob);
 360 +                       }
 361 +               } else {
 362 +                       u32 distance;
 363 +
 364 +                       rc_update_bit_1(ctx, prob);
 365 +                       prob = p + LZMA_IS_REP_G1 + ctx->state;
 366 +                       if (rc_is_bit_0(ctx, prob)) {
 367 +                               rc_update_bit_0(ctx, prob);
 368 +                               distance = ctx->rep1;
 369 +                       } else {
 370 +                               rc_update_bit_1(ctx, prob);
 371 +                               prob = p + LZMA_IS_REP_G2 + ctx->state;
 372 +                               if (rc_is_bit_0(ctx, prob)) {
 373 +                                       rc_update_bit_0(ctx, prob);
 374 +                                       distance = ctx->rep2;
 375 +                               } else {
 376 +                                       rc_update_bit_1(ctx, prob);
 377 +                                       distance = ctx->rep3;
 378 +                                       ctx->rep3 = ctx->rep2;
 379 +                               }
 380 +                               ctx->rep2 = ctx->rep1;
 381 +                       }
 382 +                       ctx->rep1 = ctx->rep0;
 383 +                       ctx->rep0 = distance;
 384 +               }
 385 +               ctx->state = ctx->state < LZMA_NUM_LIT_STATES ? 8 : 11;
 386 +               prob = p + LZMA_REP_LEN_CODER;
 387 +       }
 388 +
 389 +       prob_len = prob + LZMA_LEN_CHOICE;
 390 +       if (rc_is_bit_0(ctx, prob_len)) {
 391 +               rc_update_bit_0(ctx, prob_len);
 392 +               prob_len = (prob + LZMA_LEN_LOW
 393 +                           + (pos_state <<
 394 +                              LZMA_LEN_NUM_LOW_BITS));
 395 +               offset = 0;
 396 +               num_bits = LZMA_LEN_NUM_LOW_BITS;
 397 +       } else {
 398 +               rc_update_bit_1(ctx, prob_len);
 399 +               prob_len = prob + LZMA_LEN_CHOICE_2;
 400 +               if (rc_is_bit_0(ctx, prob_len)) {
 401 +                       rc_update_bit_0(ctx, prob_len);
 402 +                       prob_len = (prob + LZMA_LEN_MID
 403 +                                   + (pos_state <<
 404 +                                      LZMA_LEN_NUM_MID_BITS));
 405 +                       offset = 1 << LZMA_LEN_NUM_LOW_BITS;
 406 +                       num_bits = LZMA_LEN_NUM_MID_BITS;
 407 +               } else {
 408 +                       rc_update_bit_1(ctx, prob_len);
 409 +                       prob_len = prob + LZMA_LEN_HIGH;
 410 +                       offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
 411 +                                 + (1 << LZMA_LEN_NUM_MID_BITS));
 412 +                       num_bits = LZMA_LEN_NUM_HIGH_BITS;
 413 +               }
 414 +       }
 415 +
 416 +       rc_bit_tree_decode(ctx, prob_len, num_bits, &len);
 417 +       len += offset;
 418 +
 419 +       if (ctx->state < 4) {
 420 +               int pos_slot;
 421 +
 422 +               ctx->state += LZMA_NUM_LIT_STATES;
 423 +               prob =
 424 +                       p + LZMA_POS_SLOT +
 425 +                       ((len <
 426 +                         LZMA_NUM_LEN_TO_POS_STATES ? len :
 427 +                         LZMA_NUM_LEN_TO_POS_STATES - 1)
 428 +                        << LZMA_NUM_POS_SLOT_BITS);
 429 +               rc_bit_tree_decode(ctx, prob,
 430 +                                  LZMA_NUM_POS_SLOT_BITS,
 431 +                                  &pos_slot);
 432 +               if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
 433 +                       int i, mi;
 434 +                       num_bits = (pos_slot >> 1) - 1;
 435 +                       ctx->rep0 = 2 | (pos_slot & 1);
 436 +                       if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
 437 +                               ctx->rep0 <<= num_bits;
 438 +                               prob = p + LZMA_SPEC_POS +
 439 +                                       ctx->rep0 - pos_slot - 1;
 440 +                       } else {
 441 +                               num_bits -= LZMA_NUM_ALIGN_BITS;
 442 +                               while (num_bits--)
 443 +                                       ctx->rep0 = (ctx->rep0 << 1) |
 444 +                                               rc_direct_bit(ctx);
 445 +                               prob = p + LZMA_ALIGN;
 446 +                               ctx->rep0 <<= LZMA_NUM_ALIGN_BITS;
 447 +                               num_bits = LZMA_NUM_ALIGN_BITS;
 448 +                       }
 449 +                       i = 1;
 450 +                       mi = 1;
 451 +                       while (num_bits--) {
 452 +                               if (rc_get_bit(ctx, prob + mi, &mi))
 453 +                                       ctx->rep0 |= i;
 454 +                               i <<= 1;
 455 +                       }
 456 +               } else
 457 +                       ctx->rep0 = pos_slot;
 458 +               if (++(ctx->rep0) == 0)
 459 +                       return;
 460 +       }
 461 +
 462 +       len += LZMA_MATCH_MIN_LEN;
 463 +
 464 +       copy_bytes(ctx, ctx->rep0, len);
 465 +}
 466 +
 467 +
 468 +static int
 469 +do_unlzma(struct unlzma_ctx *ctx)
 470 +{
 471 +       u8 hdr_buf[sizeof(struct lzma_header)];
 472 +       struct lzma_header *header = (struct lzma_header *)hdr_buf;
 473 +       u32 pos_state_mask;
 474 +       u32 literal_pos_mask;
 475 +       int lc, pb, lp;
 476 +       int num_probs;
 477 +       int i, mi;
 478 +       u16 *p;
 479 +
 480 +       for (i = 0; i < sizeof(struct lzma_header); i++) {
 481 +               hdr_buf[i] = rc_read(ctx);
 482 +       }
 483 +
 484 +       ctx->n_buffers = 0;
 485 +       ctx->pos = 0;
 486 +       get_buffer(ctx);
 487 +       ctx->active = true;
 488 +       ctx->state = 0;
 489 +       ctx->rep0 = ctx->rep1 = ctx->rep2 = ctx->rep3 = 1;
 490 +
 491 +       ctx->previous_byte = 0;
 492 +       ctx->code = 0;
 493 +       ctx->range = 0xFFFFFFFF;
 494 +
 495 +       ctx->dict_size = le32_to_cpu(header->dict_size);
 496 +
 497 +       if (header->pos >= (9 * 5 * 5))
 498 +               return -1;
 499 +
 500 +       mi = 0;
 501 +       lc = header->pos;
 502 +       while (lc >= 9) {
 503 +               mi++;
 504 +               lc -= 9;
 505 +       }
 506 +       pb = 0;
 507 +       lp = mi;
 508 +       while (lp >= 5) {
 509 +               pb++;
 510 +               lp -= 5;
 511 +       }
 512 +       pos_state_mask = (1 << pb) - 1;
 513 +       literal_pos_mask = (1 << lp) - 1;
 514 +
 515 +       if (ctx->dict_size == 0)
 516 +               ctx->dict_size = 1;
 517 +
 518 +       num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
 519 +       if (ctx->workspace_size < num_probs * sizeof(*p)) {
 520 +               if (ctx->workspace)
 521 +                       vfree(ctx->workspace);
 522 +               ctx->workspace_size = num_probs * sizeof(*p);
 523 +               ctx->workspace = vmalloc(ctx->workspace_size);
 524 +       }
 525 +       p = (u16 *) ctx->workspace;
 526 +       if (!p)
 527 +               return -1;
 528 +
 529 +       num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
 530 +       for (i = 0; i < num_probs; i++)
 531 +               p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
 532 +
 533 +       for (i = 0; i < 5; i++)
 534 +               rc_get_code(ctx);
 535 +
 536 +       while (1) {
 537 +               int pos_state = ctx->pos & pos_state_mask;
 538 +               u16 *prob = p + LZMA_IS_MATCH +
 539 +                       (ctx->state << LZMA_NUM_POS_BITS_MAX) + pos_state;
 540 +               if (rc_is_bit_0(ctx, prob))
 541 +                       process_bit0(ctx, p, pos_state, prob,
 542 +                                    lc, literal_pos_mask);
 543 +               else {
 544 +                       process_bit1(ctx, p, pos_state, prob);
 545 +                       if (ctx->rep0 == 0)
 546 +                               break;
 547 +               }
 548 +               if (unlzma_should_stop(ctx))
 549 +                       break;
 550 +       }
 551 +       if (likely(!unlzma_should_stop(ctx)))
 552 +               rc_normalize(ctx);
 553 +
 554 +       return ctx->pos;
 555 +}
 556 +
 557 +
 558 +static void
 559 +unlzma_reset_buf(struct unlzma_ctx *ctx)
 560 +{
 561 +       ctx->avail_in = 0;
 562 +       ctx->next_in = NULL;
 563 +       ctx->avail_out = 0;
 564 +       ctx->next_out = NULL;
 565 +}
 566 +
 567 +static int
 568 +unlzma_thread(void *data)
 569 +{
 570 +       struct unlzma_ctx *ctx = data;
 571 +
 572 +       mutex_lock(&ctx->mutex);
 573 +       do {
 574 +               if (do_unlzma(ctx) < 0)
 575 +                       ctx->pos = 0;
 576 +               unlzma_reset_buf(ctx);
 577 +               ctx->cancel = false;
 578 +               ctx->active = false;
 579 +       } while (!kthread_should_stop());
 580 +       mutex_unlock(&ctx->mutex);
 581 +       return 0;
 582 +}
 583 +
 584 +
 585 +static int
 586 +unlzma_init(struct crypto_tfm *tfm)
 587 +{
 588 +       return 0;
 589 +}
 590 +
 591 +static void
 592 +unlzma_cancel(struct unlzma_ctx *ctx)
 593 +{
 594 +       unlzma_reset_buf(ctx);
 595 +
 596 +       if (!ctx->active)
 597 +               return;
 598 +
 599 +       ctx->cancel = true;
 600 +       do {
 601 +               mutex_unlock(&ctx->mutex);
 602 +               wake_up(&ctx->next_req);
 603 +               schedule();
 604 +               mutex_lock(&ctx->mutex);
 605 +       } while (ctx->cancel);
 606 +}
 607 +
 608 +
 609 +static void
 610 +unlzma_exit(struct crypto_tfm *tfm)
 611 +{
 612 +       struct unlzma_ctx *ctx = crypto_tfm_ctx(tfm);
 613 +
 614 +       if (ctx->thread) {
 615 +               unlzma_cancel(ctx);
 616 +               kthread_stop(ctx->thread);
 617 +               ctx->thread = NULL;
 618 +               if (ctx->buffers)
 619 +                       kfree(ctx->buffers);
 620 +               ctx->buffers_max = 0;
 621 +               ctx->buffers = NULL;
 622 +       }
 623 +}
 624 +
 625 +static int
 626 +unlzma_decompress_setup(struct crypto_pcomp *tfm, void *p, unsigned int len)
 627 +{
 628 +       struct unlzma_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 629 +       struct nlattr *tb[UNLZMA_DECOMP_MAX + 1];
 630 +       int ret = 0;
 631 +
 632 +       if (ctx->thread)
 633 +               return -EINVAL;
 634 +
 635 +       if (!p)
 636 +               return -EINVAL;
 637 +
 638 +       ret = nla_parse(tb, UNLZMA_DECOMP_MAX, p, len, NULL);
 639 +       if (ret)
 640 +               return ret;
 641 +
 642 +       if (!tb[UNLZMA_DECOMP_OUT_BUFFERS])
 643 +               return -EINVAL;
 644 +
 645 +       if (ctx->buffers_max && (ctx->buffers_max <
 646 +           nla_get_u32(tb[UNLZMA_DECOMP_OUT_BUFFERS]))) {
 647 +               kfree(ctx->buffers);
 648 +               ctx->buffers_max = 0;
 649 +               ctx->buffers = NULL;
 650 +       }
 651 +       if (!ctx->buffers) {
 652 +               ctx->buffers_max = nla_get_u32(tb[UNLZMA_DECOMP_OUT_BUFFERS]);
 653 +               ctx->buffers = kzalloc(sizeof(struct unlzma_buffer) * ctx->buffers_max, GFP_KERNEL);
 654 +       }
 655 +       if (!ctx->buffers)
 656 +               return -ENOMEM;
 657 +
 658 +       ctx->waiting = false;
 659 +       mutex_init(&ctx->mutex);
 660 +       init_waitqueue_head(&ctx->next_req);
 661 +       init_waitqueue_head(&ctx->req_done);
 662 +       ctx->thread = kthread_run(unlzma_thread, ctx, "unlzma/%d", instance++);
 663 +       if (IS_ERR(ctx->thread)) {
 664 +               ret = PTR_ERR(ctx->thread);
 665 +               ctx->thread = NULL;
 666 +       }
 667 +
 668 +       return ret;
 669 +}
 670 +
 671 +static int
 672 +unlzma_decompress_init(struct crypto_pcomp *tfm)
 673 +{
 674 +       return 0;
 675 +}
 676 +
 677 +static void
 678 +unlzma_wait_complete(struct unlzma_ctx *ctx, bool finish)
 679 +{
 680 +       DEFINE_WAIT(__wait);
 681 +
 682 +       do {
 683 +               wake_up(&ctx->next_req);
 684 +               prepare_to_wait(&ctx->req_done, &__wait, TASK_INTERRUPTIBLE);
 685 +               mutex_unlock(&ctx->mutex);
 686 +               schedule();
 687 +               mutex_lock(&ctx->mutex);
 688 +       } while (!ctx->waiting && ctx->active);
 689 +       finish_wait(&ctx->req_done, &__wait);
 690 +}
 691 +
 692 +static int
 693 +unlzma_decompress_update(struct crypto_pcomp *tfm, struct comp_request *req)
 694 +{
 695 +       struct unlzma_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 696 +       size_t pos = 0;
 697 +
 698 +       mutex_lock(&ctx->mutex);
 699 +       if (!ctx->active && !req->avail_in)
 700 +               goto out;
 701 +
 702 +       pos = ctx->pos;
 703 +       ctx->waiting = false;
 704 +       ctx->next_in = req->next_in;
 705 +       ctx->avail_in = req->avail_in;
 706 +       ctx->next_out = req->next_out;
 707 +       ctx->avail_out = req->avail_out;
 708 +
 709 +       unlzma_wait_complete(ctx, false);
 710 +
 711 +       req->next_in = ctx->next_in;
 712 +       req->avail_in = ctx->avail_in;
 713 +       req->next_out = ctx->next_out;
 714 +       req->avail_out = ctx->avail_out;
 715 +       ctx->next_in = 0;
 716 +       ctx->avail_in = 0;
 717 +       pos = ctx->pos - pos;
 718 +
 719 +out:
 720 +       mutex_unlock(&ctx->mutex);
 721 +       if (ctx->cancel)
 722 +               return -EINVAL;
 723 +
 724 +       return pos;
 725 +}
 726 +
 727 +static int
 728 +unlzma_decompress_final(struct crypto_pcomp *tfm, struct comp_request *req)
 729 +{
 730 +       struct unlzma_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 731 +       int ret = 0;
 732 +
 733 +       /* cancel pending operation */
 734 +       mutex_lock(&ctx->mutex);
 735 +       if (ctx->active) {
 736 +               // ret = -EINVAL;
 737 +               unlzma_cancel(ctx);
 738 +       }
 739 +       ctx->pos = 0;
 740 +       mutex_unlock(&ctx->mutex);
 741 +       return ret;
 742 +}
 743 +
 744 +
 745 +static struct pcomp_alg unlzma_alg = {
 746 +       .decompress_setup       = unlzma_decompress_setup,
 747 +       .decompress_init        = unlzma_decompress_init,
 748 +       .decompress_update      = unlzma_decompress_update,
 749 +       .decompress_final       = unlzma_decompress_final,
 750 +
 751 +       .base                   = {
 752 +               .cra_name       = "lzma",
 753 +               .cra_flags      = CRYPTO_ALG_TYPE_PCOMPRESS,
 754 +               .cra_ctxsize    = sizeof(struct unlzma_ctx),
 755 +               .cra_module     = THIS_MODULE,
 756 +               .cra_init       = unlzma_init,
 757 +               .cra_exit       = unlzma_exit,
 758 +       }
 759 +};
 760 +
 761 +static int __init
 762 +unlzma_mod_init(void)
 763 +{
 764 +       return crypto_register_pcomp(&unlzma_alg);
 765 +}
 766 +
 767 +static void __exit
 768 +unlzma_mod_exit(void)
 769 +{
 770 +       crypto_unregister_pcomp(&unlzma_alg);
 771 +}
 772 +
 773 +module_init(unlzma_mod_init);
 774 +module_exit(unlzma_mod_exit);
 775 +
 776 +MODULE_LICENSE("GPL");
 777 +MODULE_DESCRIPTION("LZMA Decompression Algorithm");
 778 +MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
 779 --- a/crypto/Kconfig
 780 +++ b/crypto/Kconfig
 781 @@ -768,6 +768,12 @@ config CRYPTO_ZLIB
 782         help
 783           This is the zlib algorithm.
 784
 785 +config CRYPTO_UNLZMA
 786 +       tristate "LZMA decompression"
 787 +       select CRYPTO_PCOMP
 788 +       help
 789 +         This is the lzma decompression module.
 790 +
 791  config CRYPTO_LZO
 792         tristate "LZO compression algorithm"
 793         select CRYPTO_ALGAPI
 794 --- a/crypto/Makefile
 795 +++ b/crypto/Makefile
 796 @@ -75,6 +75,7 @@ obj-$(CONFIG_CRYPTO_SEED) += seed.o
 797  obj-$(CONFIG_CRYPTO_SALSA20) += salsa20_generic.o
 798  obj-$(CONFIG_CRYPTO_DEFLATE) += deflate.o
 799  obj-$(CONFIG_CRYPTO_ZLIB) += zlib.o
 800 +obj-$(CONFIG_CRYPTO_UNLZMA) += unlzma.o
 801  obj-$(CONFIG_CRYPTO_MICHAEL_MIC) += michael_mic.o
 802  obj-$(CONFIG_CRYPTO_CRC32C) += crc32c.o
 803  obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o
 804 --- /dev/null
 805 +++ b/crypto/unlzma.h
 806 @@ -0,0 +1,80 @@
 807 +/* LZMA uncompresion module for pcomp
 808 + * Copyright (C) 2009  Felix Fietkau <nbd@openwrt.org>
 809 + *
 810 + * Based on:
 811 + *  Initial Linux kernel adaptation
 812 + *  Copyright (C) 2006  Alain < alain@knaff.lu >
 813 + *
 814 + *  Based on small lzma deflate implementation/Small range coder
 815 + *  implementation for lzma.
 816 + *  Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
 817 + *
 818 + *  Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
 819 + *  Copyright (C) 1999-2005  Igor Pavlov
 820 + *
 821 + * This program is free software; you can redistribute it and/or modify it
 822 + * under the terms of the GNU General Public License version 2 as published
 823 + * by the Free Software Foundation.
 824 + */
 825 +#ifndef __UNLZMA_H
 826 +#define __UNLZMA_H
 827 +
 828 +struct lzma_header {
 829 +       __u8 pos;
 830 +       __le32 dict_size;
 831 +} __attribute__ ((packed)) ;
 832 +
 833 +
 834 +#define RC_TOP_BITS 24
 835 +#define RC_MOVE_BITS 5
 836 +#define RC_MODEL_TOTAL_BITS 11
 837 +
 838 +#define LZMA_BASE_SIZE 1846
 839 +#define LZMA_LIT_SIZE 768
 840 +
 841 +#define LZMA_NUM_POS_BITS_MAX 4
 842 +
 843 +#define LZMA_LEN_NUM_LOW_BITS 3
 844 +#define LZMA_LEN_NUM_MID_BITS 3
 845 +#define LZMA_LEN_NUM_HIGH_BITS 8
 846 +
 847 +#define LZMA_LEN_CHOICE 0
 848 +#define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
 849 +#define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
 850 +#define LZMA_LEN_MID (LZMA_LEN_LOW \
 851 +                     + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
 852 +#define LZMA_LEN_HIGH (LZMA_LEN_MID \
 853 +                      +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
 854 +#define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
 855 +
 856 +#define LZMA_NUM_STATES 12
 857 +#define LZMA_NUM_LIT_STATES 7
 858 +
 859 +#define LZMA_START_POS_MODEL_INDEX 4
 860 +#define LZMA_END_POS_MODEL_INDEX 14
 861 +#define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
 862 +
 863 +#define LZMA_NUM_POS_SLOT_BITS 6
 864 +#define LZMA_NUM_LEN_TO_POS_STATES 4
 865 +
 866 +#define LZMA_NUM_ALIGN_BITS 4
 867 +
 868 +#define LZMA_MATCH_MIN_LEN 2
 869 +
 870 +#define LZMA_IS_MATCH 0
 871 +#define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
 872 +#define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
 873 +#define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
 874 +#define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
 875 +#define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
 876 +#define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
 877 +                      + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
 878 +#define LZMA_SPEC_POS (LZMA_POS_SLOT \
 879 +                      +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
 880 +#define LZMA_ALIGN (LZMA_SPEC_POS \
 881 +                   + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
 882 +#define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
 883 +#define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
 884 +#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
 885 +
 886 +#endif
 887 --- a/include/crypto/compress.h
 888 +++ b/include/crypto/compress.h
 889 @@ -49,6 +49,12 @@ enum zlib_decomp_params {
 890
 891  #define ZLIB_DECOMP_MAX        (__ZLIB_DECOMP_MAX - 1)
 892
 893 +enum unlzma_decomp_params {
 894 +       UNLZMA_DECOMP_OUT_BUFFERS = 1, /* naximum number of output buffers */
 895 +       __UNLZMA_DECOMP_MAX,
 896 +};
 897 +#define UNLZMA_DECOMP_MAX      (__UNLZMA_DECOMP_MAX - 1)
 898 +
 899
 900  struct crypto_pcomp {
 901         struct crypto_tfm base;