1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * 842 Software Compression |
4 | * |
5 | * Copyright (C) 2015 Dan Streetman, IBM Corp |
6 | * |
7 | * See 842.h for details of the 842 compressed format. |
8 | */ |
9 | |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | #define MODULE_NAME "842_compress" |
12 | |
13 | #include <linux/hashtable.h> |
14 | |
15 | #include "842.h" |
16 | #include "842_debugfs.h" |
17 | |
18 | #define SW842_HASHTABLE8_BITS (10) |
19 | #define SW842_HASHTABLE4_BITS (11) |
20 | #define SW842_HASHTABLE2_BITS (10) |
21 | |
22 | /* By default, we allow compressing input buffers of any length, but we must |
23 | * use the non-standard "short data" template so the decompressor can correctly |
24 | * reproduce the uncompressed data buffer at the right length. However the |
25 | * hardware 842 compressor will not recognize the "short data" template, and |
26 | * will fail to decompress any compressed buffer containing it (I have no idea |
27 | * why anyone would want to use software to compress and hardware to decompress |
28 | * but that's beside the point). This parameter forces the compression |
29 | * function to simply reject any input buffer that isn't a multiple of 8 bytes |
30 | * long, instead of using the "short data" template, so that all compressed |
31 | * buffers produced by this function will be decompressable by the 842 hardware |
32 | * decompressor. Unless you have a specific need for that, leave this disabled |
33 | * so that any length buffer can be compressed. |
34 | */ |
35 | static bool sw842_strict; |
36 | module_param_named(strict, sw842_strict, bool, 0644); |
37 | |
38 | static u8 comp_ops[OPS_MAX][5] = { /* params size in bits */ |
39 | { I8, N0, N0, N0, 0x19 }, /* 8 */ |
40 | { I4, I4, N0, N0, 0x18 }, /* 18 */ |
41 | { I4, I2, I2, N0, 0x17 }, /* 25 */ |
42 | { I2, I2, I4, N0, 0x13 }, /* 25 */ |
43 | { I2, I2, I2, I2, 0x12 }, /* 32 */ |
44 | { I4, I2, D2, N0, 0x16 }, /* 33 */ |
45 | { I4, D2, I2, N0, 0x15 }, /* 33 */ |
46 | { I2, D2, I4, N0, 0x0e }, /* 33 */ |
47 | { D2, I2, I4, N0, 0x09 }, /* 33 */ |
48 | { I2, I2, I2, D2, 0x11 }, /* 40 */ |
49 | { I2, I2, D2, I2, 0x10 }, /* 40 */ |
50 | { I2, D2, I2, I2, 0x0d }, /* 40 */ |
51 | { D2, I2, I2, I2, 0x08 }, /* 40 */ |
52 | { I4, D4, N0, N0, 0x14 }, /* 41 */ |
53 | { D4, I4, N0, N0, 0x04 }, /* 41 */ |
54 | { I2, I2, D4, N0, 0x0f }, /* 48 */ |
55 | { I2, D2, I2, D2, 0x0c }, /* 48 */ |
56 | { I2, D4, I2, N0, 0x0b }, /* 48 */ |
57 | { D2, I2, I2, D2, 0x07 }, /* 48 */ |
58 | { D2, I2, D2, I2, 0x06 }, /* 48 */ |
59 | { D4, I2, I2, N0, 0x03 }, /* 48 */ |
60 | { I2, D2, D4, N0, 0x0a }, /* 56 */ |
61 | { D2, I2, D4, N0, 0x05 }, /* 56 */ |
62 | { D4, I2, D2, N0, 0x02 }, /* 56 */ |
63 | { D4, D2, I2, N0, 0x01 }, /* 56 */ |
64 | { D8, N0, N0, N0, 0x00 }, /* 64 */ |
65 | }; |
66 | |
67 | struct sw842_hlist_node8 { |
68 | struct hlist_node node; |
69 | u64 data; |
70 | u8 index; |
71 | }; |
72 | |
73 | struct sw842_hlist_node4 { |
74 | struct hlist_node node; |
75 | u32 data; |
76 | u16 index; |
77 | }; |
78 | |
79 | struct sw842_hlist_node2 { |
80 | struct hlist_node node; |
81 | u16 data; |
82 | u8 index; |
83 | }; |
84 | |
85 | #define INDEX_NOT_FOUND (-1) |
86 | #define INDEX_NOT_CHECKED (-2) |
87 | |
88 | struct sw842_param { |
89 | u8 *in; |
90 | u8 *instart; |
91 | u64 ilen; |
92 | u8 *out; |
93 | u64 olen; |
94 | u8 bit; |
95 | u64 data8[1]; |
96 | u32 data4[2]; |
97 | u16 data2[4]; |
98 | int index8[1]; |
99 | int index4[2]; |
100 | int index2[4]; |
101 | DECLARE_HASHTABLE(htable8, SW842_HASHTABLE8_BITS); |
102 | DECLARE_HASHTABLE(htable4, SW842_HASHTABLE4_BITS); |
103 | DECLARE_HASHTABLE(htable2, SW842_HASHTABLE2_BITS); |
104 | struct sw842_hlist_node8 node8[1 << I8_BITS]; |
105 | struct sw842_hlist_node4 node4[1 << I4_BITS]; |
106 | struct sw842_hlist_node2 node2[1 << I2_BITS]; |
107 | }; |
108 | |
109 | #define get_input_data(p, o, b) \ |
110 | be##b##_to_cpu(get_unaligned((__be##b *)((p)->in + (o)))) |
111 | |
112 | #define init_hashtable_nodes(p, b) do { \ |
113 | int _i; \ |
114 | hash_init((p)->htable##b); \ |
115 | for (_i = 0; _i < ARRAY_SIZE((p)->node##b); _i++) { \ |
116 | (p)->node##b[_i].index = _i; \ |
117 | (p)->node##b[_i].data = 0; \ |
118 | INIT_HLIST_NODE(&(p)->node##b[_i].node); \ |
119 | } \ |
120 | } while (0) |
121 | |
122 | #define find_index(p, b, n) ({ \ |
123 | struct sw842_hlist_node##b *_n; \ |
124 | p->index##b[n] = INDEX_NOT_FOUND; \ |
125 | hash_for_each_possible(p->htable##b, _n, node, p->data##b[n]) { \ |
126 | if (p->data##b[n] == _n->data) { \ |
127 | p->index##b[n] = _n->index; \ |
128 | break; \ |
129 | } \ |
130 | } \ |
131 | p->index##b[n] >= 0; \ |
132 | }) |
133 | |
134 | #define check_index(p, b, n) \ |
135 | ((p)->index##b[n] == INDEX_NOT_CHECKED \ |
136 | ? find_index(p, b, n) \ |
137 | : (p)->index##b[n] >= 0) |
138 | |
139 | #define replace_hash(p, b, i, d) do { \ |
140 | struct sw842_hlist_node##b *_n = &(p)->node##b[(i)+(d)]; \ |
141 | hash_del(&_n->node); \ |
142 | _n->data = (p)->data##b[d]; \ |
143 | pr_debug("add hash index%x %x pos %x data %lx\n", b, \ |
144 | (unsigned int)_n->index, \ |
145 | (unsigned int)((p)->in - (p)->instart), \ |
146 | (unsigned long)_n->data); \ |
147 | hash_add((p)->htable##b, &_n->node, _n->data); \ |
148 | } while (0) |
149 | |
150 | static u8 bmask[8] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe }; |
151 | |
152 | static int add_bits(struct sw842_param *p, u64 d, u8 n); |
153 | |
154 | static int __split_add_bits(struct sw842_param *p, u64 d, u8 n, u8 s) |
155 | { |
156 | int ret; |
157 | |
158 | if (n <= s) |
159 | return -EINVAL; |
160 | |
161 | ret = add_bits(p, d: d >> s, n: n - s); |
162 | if (ret) |
163 | return ret; |
164 | return add_bits(p, d: d & GENMASK_ULL(s - 1, 0), n: s); |
165 | } |
166 | |
167 | static int add_bits(struct sw842_param *p, u64 d, u8 n) |
168 | { |
169 | int b = p->bit, bits = b + n, s = round_up(bits, 8) - bits; |
170 | u64 o; |
171 | u8 *out = p->out; |
172 | |
173 | pr_debug("add %u bits %lx\n" , (unsigned char)n, (unsigned long)d); |
174 | |
175 | if (n > 64) |
176 | return -EINVAL; |
177 | |
178 | /* split this up if writing to > 8 bytes (i.e. n == 64 && p->bit > 0), |
179 | * or if we're at the end of the output buffer and would write past end |
180 | */ |
181 | if (bits > 64) |
182 | return __split_add_bits(p, d, n, s: 32); |
183 | else if (p->olen < 8 && bits > 32 && bits <= 56) |
184 | return __split_add_bits(p, d, n, s: 16); |
185 | else if (p->olen < 4 && bits > 16 && bits <= 24) |
186 | return __split_add_bits(p, d, n, s: 8); |
187 | |
188 | if (DIV_ROUND_UP(bits, 8) > p->olen) |
189 | return -ENOSPC; |
190 | |
191 | o = *out & bmask[b]; |
192 | d <<= s; |
193 | |
194 | if (bits <= 8) |
195 | *out = o | d; |
196 | else if (bits <= 16) |
197 | put_unaligned(cpu_to_be16(o << 8 | d), (__be16 *)out); |
198 | else if (bits <= 24) |
199 | put_unaligned(cpu_to_be32(o << 24 | d << 8), (__be32 *)out); |
200 | else if (bits <= 32) |
201 | put_unaligned(cpu_to_be32(o << 24 | d), (__be32 *)out); |
202 | else if (bits <= 40) |
203 | put_unaligned(cpu_to_be64(o << 56 | d << 24), (__be64 *)out); |
204 | else if (bits <= 48) |
205 | put_unaligned(cpu_to_be64(o << 56 | d << 16), (__be64 *)out); |
206 | else if (bits <= 56) |
207 | put_unaligned(cpu_to_be64(o << 56 | d << 8), (__be64 *)out); |
208 | else |
209 | put_unaligned(cpu_to_be64(o << 56 | d), (__be64 *)out); |
210 | |
211 | p->bit += n; |
212 | |
213 | if (p->bit > 7) { |
214 | p->out += p->bit / 8; |
215 | p->olen -= p->bit / 8; |
216 | p->bit %= 8; |
217 | } |
218 | |
219 | return 0; |
220 | } |
221 | |
222 | static int add_template(struct sw842_param *p, u8 c) |
223 | { |
224 | int ret, i, b = 0; |
225 | u8 *t = comp_ops[c]; |
226 | bool inv = false; |
227 | |
228 | if (c >= OPS_MAX) |
229 | return -EINVAL; |
230 | |
231 | pr_debug("template %x\n" , t[4]); |
232 | |
233 | ret = add_bits(p, d: t[4], OP_BITS); |
234 | if (ret) |
235 | return ret; |
236 | |
237 | for (i = 0; i < 4; i++) { |
238 | pr_debug("op %x\n" , t[i]); |
239 | |
240 | switch (t[i] & OP_AMOUNT) { |
241 | case OP_AMOUNT_8: |
242 | if (b) |
243 | inv = true; |
244 | else if (t[i] & OP_ACTION_INDEX) |
245 | ret = add_bits(p, d: p->index8[0], I8_BITS); |
246 | else if (t[i] & OP_ACTION_DATA) |
247 | ret = add_bits(p, d: p->data8[0], n: 64); |
248 | else |
249 | inv = true; |
250 | break; |
251 | case OP_AMOUNT_4: |
252 | if (b == 2 && t[i] & OP_ACTION_DATA) |
253 | ret = add_bits(p, get_input_data(p, 2, 32), n: 32); |
254 | else if (b != 0 && b != 4) |
255 | inv = true; |
256 | else if (t[i] & OP_ACTION_INDEX) |
257 | ret = add_bits(p, d: p->index4[b >> 2], I4_BITS); |
258 | else if (t[i] & OP_ACTION_DATA) |
259 | ret = add_bits(p, d: p->data4[b >> 2], n: 32); |
260 | else |
261 | inv = true; |
262 | break; |
263 | case OP_AMOUNT_2: |
264 | if (b != 0 && b != 2 && b != 4 && b != 6) |
265 | inv = true; |
266 | if (t[i] & OP_ACTION_INDEX) |
267 | ret = add_bits(p, d: p->index2[b >> 1], I2_BITS); |
268 | else if (t[i] & OP_ACTION_DATA) |
269 | ret = add_bits(p, d: p->data2[b >> 1], n: 16); |
270 | else |
271 | inv = true; |
272 | break; |
273 | case OP_AMOUNT_0: |
274 | inv = (b != 8) || !(t[i] & OP_ACTION_NOOP); |
275 | break; |
276 | default: |
277 | inv = true; |
278 | break; |
279 | } |
280 | |
281 | if (ret) |
282 | return ret; |
283 | |
284 | if (inv) { |
285 | pr_err("Invalid templ %x op %d : %x %x %x %x\n" , |
286 | c, i, t[0], t[1], t[2], t[3]); |
287 | return -EINVAL; |
288 | } |
289 | |
290 | b += t[i] & OP_AMOUNT; |
291 | } |
292 | |
293 | if (b != 8) { |
294 | pr_err("Invalid template %x len %x : %x %x %x %x\n" , |
295 | c, b, t[0], t[1], t[2], t[3]); |
296 | return -EINVAL; |
297 | } |
298 | |
299 | if (sw842_template_counts) |
300 | atomic_inc(v: &template_count[t[4]]); |
301 | |
302 | return 0; |
303 | } |
304 | |
305 | static int add_repeat_template(struct sw842_param *p, u8 r) |
306 | { |
307 | int ret; |
308 | |
309 | /* repeat param is 0-based */ |
310 | if (!r || --r > REPEAT_BITS_MAX) |
311 | return -EINVAL; |
312 | |
313 | ret = add_bits(p, OP_REPEAT, OP_BITS); |
314 | if (ret) |
315 | return ret; |
316 | |
317 | ret = add_bits(p, d: r, REPEAT_BITS); |
318 | if (ret) |
319 | return ret; |
320 | |
321 | if (sw842_template_counts) |
322 | atomic_inc(v: &template_repeat_count); |
323 | |
324 | return 0; |
325 | } |
326 | |
327 | static int add_short_data_template(struct sw842_param *p, u8 b) |
328 | { |
329 | int ret, i; |
330 | |
331 | if (!b || b > SHORT_DATA_BITS_MAX) |
332 | return -EINVAL; |
333 | |
334 | ret = add_bits(p, OP_SHORT_DATA, OP_BITS); |
335 | if (ret) |
336 | return ret; |
337 | |
338 | ret = add_bits(p, d: b, SHORT_DATA_BITS); |
339 | if (ret) |
340 | return ret; |
341 | |
342 | for (i = 0; i < b; i++) { |
343 | ret = add_bits(p, d: p->in[i], n: 8); |
344 | if (ret) |
345 | return ret; |
346 | } |
347 | |
348 | if (sw842_template_counts) |
349 | atomic_inc(v: &template_short_data_count); |
350 | |
351 | return 0; |
352 | } |
353 | |
354 | static int add_zeros_template(struct sw842_param *p) |
355 | { |
356 | int ret = add_bits(p, OP_ZEROS, OP_BITS); |
357 | |
358 | if (ret) |
359 | return ret; |
360 | |
361 | if (sw842_template_counts) |
362 | atomic_inc(v: &template_zeros_count); |
363 | |
364 | return 0; |
365 | } |
366 | |
367 | static int add_end_template(struct sw842_param *p) |
368 | { |
369 | int ret = add_bits(p, OP_END, OP_BITS); |
370 | |
371 | if (ret) |
372 | return ret; |
373 | |
374 | if (sw842_template_counts) |
375 | atomic_inc(v: &template_end_count); |
376 | |
377 | return 0; |
378 | } |
379 | |
380 | static bool check_template(struct sw842_param *p, u8 c) |
381 | { |
382 | u8 *t = comp_ops[c]; |
383 | int i, match, b = 0; |
384 | |
385 | if (c >= OPS_MAX) |
386 | return false; |
387 | |
388 | for (i = 0; i < 4; i++) { |
389 | if (t[i] & OP_ACTION_INDEX) { |
390 | if (t[i] & OP_AMOUNT_2) |
391 | match = check_index(p, 2, b >> 1); |
392 | else if (t[i] & OP_AMOUNT_4) |
393 | match = check_index(p, 4, b >> 2); |
394 | else if (t[i] & OP_AMOUNT_8) |
395 | match = check_index(p, 8, 0); |
396 | else |
397 | return false; |
398 | if (!match) |
399 | return false; |
400 | } |
401 | |
402 | b += t[i] & OP_AMOUNT; |
403 | } |
404 | |
405 | return true; |
406 | } |
407 | |
408 | static void get_next_data(struct sw842_param *p) |
409 | { |
410 | p->data8[0] = get_input_data(p, 0, 64); |
411 | p->data4[0] = get_input_data(p, 0, 32); |
412 | p->data4[1] = get_input_data(p, 4, 32); |
413 | p->data2[0] = get_input_data(p, 0, 16); |
414 | p->data2[1] = get_input_data(p, 2, 16); |
415 | p->data2[2] = get_input_data(p, 4, 16); |
416 | p->data2[3] = get_input_data(p, 6, 16); |
417 | } |
418 | |
419 | /* update the hashtable entries. |
420 | * only call this after finding/adding the current template |
421 | * the dataN fields for the current 8 byte block must be already updated |
422 | */ |
423 | static void update_hashtables(struct sw842_param *p) |
424 | { |
425 | u64 pos = p->in - p->instart; |
426 | u64 n8 = (pos >> 3) % (1 << I8_BITS); |
427 | u64 n4 = (pos >> 2) % (1 << I4_BITS); |
428 | u64 n2 = (pos >> 1) % (1 << I2_BITS); |
429 | |
430 | replace_hash(p, 8, n8, 0); |
431 | replace_hash(p, 4, n4, 0); |
432 | replace_hash(p, 4, n4, 1); |
433 | replace_hash(p, 2, n2, 0); |
434 | replace_hash(p, 2, n2, 1); |
435 | replace_hash(p, 2, n2, 2); |
436 | replace_hash(p, 2, n2, 3); |
437 | } |
438 | |
439 | /* find the next template to use, and add it |
440 | * the p->dataN fields must already be set for the current 8 byte block |
441 | */ |
442 | static int process_next(struct sw842_param *p) |
443 | { |
444 | int ret, i; |
445 | |
446 | p->index8[0] = INDEX_NOT_CHECKED; |
447 | p->index4[0] = INDEX_NOT_CHECKED; |
448 | p->index4[1] = INDEX_NOT_CHECKED; |
449 | p->index2[0] = INDEX_NOT_CHECKED; |
450 | p->index2[1] = INDEX_NOT_CHECKED; |
451 | p->index2[2] = INDEX_NOT_CHECKED; |
452 | p->index2[3] = INDEX_NOT_CHECKED; |
453 | |
454 | /* check up to OPS_MAX - 1; last op is our fallback */ |
455 | for (i = 0; i < OPS_MAX - 1; i++) { |
456 | if (check_template(p, c: i)) |
457 | break; |
458 | } |
459 | |
460 | ret = add_template(p, c: i); |
461 | if (ret) |
462 | return ret; |
463 | |
464 | return 0; |
465 | } |
466 | |
467 | /** |
468 | * sw842_compress |
469 | * |
470 | * Compress the uncompressed buffer of length @ilen at @in to the output buffer |
471 | * @out, using no more than @olen bytes, using the 842 compression format. |
472 | * |
473 | * Returns: 0 on success, error on failure. The @olen parameter |
474 | * will contain the number of output bytes written on success, or |
475 | * 0 on error. |
476 | */ |
477 | int sw842_compress(const u8 *in, unsigned int ilen, |
478 | u8 *out, unsigned int *olen, void *wmem) |
479 | { |
480 | struct sw842_param *p = (struct sw842_param *)wmem; |
481 | int ret; |
482 | u64 last, next, pad, total; |
483 | u8 repeat_count = 0; |
484 | u32 crc; |
485 | |
486 | BUILD_BUG_ON(sizeof(*p) > SW842_MEM_COMPRESS); |
487 | |
488 | init_hashtable_nodes(p, 8); |
489 | init_hashtable_nodes(p, 4); |
490 | init_hashtable_nodes(p, 2); |
491 | |
492 | p->in = (u8 *)in; |
493 | p->instart = p->in; |
494 | p->ilen = ilen; |
495 | p->out = out; |
496 | p->olen = *olen; |
497 | p->bit = 0; |
498 | |
499 | total = p->olen; |
500 | |
501 | *olen = 0; |
502 | |
503 | /* if using strict mode, we can only compress a multiple of 8 */ |
504 | if (sw842_strict && (ilen % 8)) { |
505 | pr_err("Using strict mode, can't compress len %d\n" , ilen); |
506 | return -EINVAL; |
507 | } |
508 | |
509 | /* let's compress at least 8 bytes, mkay? */ |
510 | if (unlikely(ilen < 8)) |
511 | goto skip_comp; |
512 | |
513 | /* make initial 'last' different so we don't match the first time */ |
514 | last = ~get_unaligned((u64 *)p->in); |
515 | |
516 | while (p->ilen > 7) { |
517 | next = get_unaligned((u64 *)p->in); |
518 | |
519 | /* must get the next data, as we need to update the hashtable |
520 | * entries with the new data every time |
521 | */ |
522 | get_next_data(p); |
523 | |
524 | /* we don't care about endianness in last or next; |
525 | * we're just comparing 8 bytes to another 8 bytes, |
526 | * they're both the same endianness |
527 | */ |
528 | if (next == last) { |
529 | /* repeat count bits are 0-based, so we stop at +1 */ |
530 | if (++repeat_count <= REPEAT_BITS_MAX) |
531 | goto repeat; |
532 | } |
533 | if (repeat_count) { |
534 | ret = add_repeat_template(p, r: repeat_count); |
535 | repeat_count = 0; |
536 | if (next == last) /* reached max repeat bits */ |
537 | goto repeat; |
538 | } |
539 | |
540 | if (next == 0) |
541 | ret = add_zeros_template(p); |
542 | else |
543 | ret = process_next(p); |
544 | |
545 | if (ret) |
546 | return ret; |
547 | |
548 | repeat: |
549 | last = next; |
550 | update_hashtables(p); |
551 | p->in += 8; |
552 | p->ilen -= 8; |
553 | } |
554 | |
555 | if (repeat_count) { |
556 | ret = add_repeat_template(p, r: repeat_count); |
557 | if (ret) |
558 | return ret; |
559 | } |
560 | |
561 | skip_comp: |
562 | if (p->ilen > 0) { |
563 | ret = add_short_data_template(p, b: p->ilen); |
564 | if (ret) |
565 | return ret; |
566 | |
567 | p->in += p->ilen; |
568 | p->ilen = 0; |
569 | } |
570 | |
571 | ret = add_end_template(p); |
572 | if (ret) |
573 | return ret; |
574 | |
575 | /* |
576 | * crc(0:31) is appended to target data starting with the next |
577 | * bit after End of stream template. |
578 | * nx842 calculates CRC for data in big-endian format. So doing |
579 | * same here so that sw842 decompression can be used for both |
580 | * compressed data. |
581 | */ |
582 | crc = crc32_be(crc: 0, p: in, len: ilen); |
583 | ret = add_bits(p, d: crc, CRC_BITS); |
584 | if (ret) |
585 | return ret; |
586 | |
587 | if (p->bit) { |
588 | p->out++; |
589 | p->olen--; |
590 | p->bit = 0; |
591 | } |
592 | |
593 | /* pad compressed length to multiple of 8 */ |
594 | pad = (8 - ((total - p->olen) % 8)) % 8; |
595 | if (pad) { |
596 | if (pad > p->olen) /* we were so close! */ |
597 | return -ENOSPC; |
598 | memset(p->out, 0, pad); |
599 | p->out += pad; |
600 | p->olen -= pad; |
601 | } |
602 | |
603 | if (unlikely((total - p->olen) > UINT_MAX)) |
604 | return -ENOSPC; |
605 | |
606 | *olen = total - p->olen; |
607 | |
608 | return 0; |
609 | } |
610 | EXPORT_SYMBOL_GPL(sw842_compress); |
611 | |
612 | static int __init sw842_init(void) |
613 | { |
614 | if (sw842_template_counts) |
615 | sw842_debugfs_create(); |
616 | |
617 | return 0; |
618 | } |
619 | module_init(sw842_init); |
620 | |
621 | static void __exit sw842_exit(void) |
622 | { |
623 | if (sw842_template_counts) |
624 | sw842_debugfs_remove(); |
625 | } |
626 | module_exit(sw842_exit); |
627 | |
628 | MODULE_LICENSE("GPL" ); |
629 | MODULE_DESCRIPTION("Software 842 Compressor" ); |
630 | MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>" ); |
631 | |