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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / crypto / nx / nx-842.c
blob2ab90ec10e61ebe8784b77ea1281533ed8fca922
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Cryptographic API for the NX-842 hardware compression.
4 *
5 * Copyright (C) IBM Corporation, 2011-2015
6 *
7 * Designer of the Power data compression engine:
8 * Bulent Abali <abali@us.ibm.com>
9 *
10 * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
11 * Seth Jennings <sjenning@linux.vnet.ibm.com>
12 *
13 * Rewrite: Dan Streetman <ddstreet@ieee.org>
14 *
15 * This is an interface to the NX-842 compression hardware in PowerPC
16 * processors. Most of the complexity of this drvier is due to the fact that
17 * the NX-842 compression hardware requires the input and output data buffers
18 * to be specifically aligned, to be a specific multiple in length, and within
19 * specific minimum and maximum lengths. Those restrictions, provided by the
20 * nx-842 driver via nx842_constraints, mean this driver must use bounce
21 * buffers and headers to correct misaligned in or out buffers, and to split
22 * input buffers that are too large.
23 *
24 * This driver will fall back to software decompression if the hardware
25 * decompression fails, so this driver's decompression should never fail as
26 * long as the provided compressed buffer is valid. Any compressed buffer
27 * created by this driver will have a header (except ones where the input
28 * perfectly matches the constraints); so users of this driver cannot simply
29 * pass a compressed buffer created by this driver over to the 842 software
30 * decompression library. Instead, users must use this driver to decompress;
31 * if the hardware fails or is unavailable, the compressed buffer will be
32 * parsed and the header removed, and the raw 842 buffer(s) passed to the 842
33 * software decompression library.
34 *
35 * This does not fall back to software compression, however, since the caller
36 * of this function is specifically requesting hardware compression; if the
37 * hardware compression fails, the caller can fall back to software
38 * compression, and the raw 842 compressed buffer that the software compressor
39 * creates can be passed to this driver for hardware decompression; any
40 * buffer without our specific header magic is assumed to be a raw 842 buffer
41 * and passed directly to the hardware. Note that the software compression
42 * library will produce a compressed buffer that is incompatible with the
43 * hardware decompressor if the original input buffer length is not a multiple
44 * of 8; if such a compressed buffer is passed to this driver for
45 * decompression, the hardware will reject it and this driver will then pass
46 * it over to the software library for decompression.
47 */
48
49 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50
51 #include <linux/vmalloc.h>
52 #include <linux/sw842.h>
53 #include <linux/spinlock.h>
54
55 #include "nx-842.h"
56
57 /* The first 5 bits of this magic are 0x1f, which is an invalid 842 5-bit
58 * template (see lib/842/842.h), so this magic number will never appear at
59 * the start of a raw 842 compressed buffer. That is important, as any buffer
60 * passed to us without this magic is assumed to be a raw 842 compressed
61 * buffer, and passed directly to the hardware to decompress.
62 */
63 #define NX842_CRYPTO_MAGIC (0xf842)
64 #define NX842_CRYPTO_HEADER_SIZE(g) \
65 (sizeof(struct nx842_crypto_header) + \
66 sizeof(struct nx842_crypto_header_group) * (g))
67 #define NX842_CRYPTO_HEADER_MAX_SIZE \
68 NX842_CRYPTO_HEADER_SIZE(NX842_CRYPTO_GROUP_MAX)
69
70 /* bounce buffer size */
71 #define BOUNCE_BUFFER_ORDER (2)
72 #define BOUNCE_BUFFER_SIZE \
73 ((unsigned int)(PAGE_SIZE << BOUNCE_BUFFER_ORDER))
74
75 /* try longer on comp because we can fallback to sw decomp if hw is busy */
76 #define COMP_BUSY_TIMEOUT (250) /* ms */
77 #define DECOMP_BUSY_TIMEOUT (50) /* ms */
78
79 struct nx842_crypto_param {
80 u8 *in;
81 unsigned int iremain;
82 u8 *out;
83 unsigned int oremain;
84 unsigned int ototal;
85 };
86
87 static int update_param(struct nx842_crypto_param *p,
88 unsigned int slen, unsigned int dlen)
89 {
90 if (p->iremain < slen)
91 return -EOVERFLOW;
92 if (p->oremain < dlen)
93 return -ENOSPC;
94
95 p->in += slen;
96 p->iremain -= slen;
97 p->out += dlen;
98 p->oremain -= dlen;
99 p->ototal += dlen;
100
101 return 0;
102 }
103
104 int nx842_crypto_init(struct crypto_tfm *tfm, struct nx842_driver *driver)
105 {
106 struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
107
108 spin_lock_init(&ctx->lock);
109 ctx->driver = driver;
110 ctx->wmem = kmalloc(driver->workmem_size, GFP_KERNEL);
111 ctx->sbounce = (u8 *)__get_free_pages(GFP_KERNEL, BOUNCE_BUFFER_ORDER);
112 ctx->dbounce = (u8 *)__get_free_pages(GFP_KERNEL, BOUNCE_BUFFER_ORDER);
113 if (!ctx->wmem || !ctx->sbounce || !ctx->dbounce) {
114 kfree(ctx->wmem);
115 free_page((unsigned long)ctx->sbounce);
116 free_page((unsigned long)ctx->dbounce);
117 return -ENOMEM;
118 }
119
120 return 0;
121 }
122 EXPORT_SYMBOL_GPL(nx842_crypto_init);
123
124 void nx842_crypto_exit(struct crypto_tfm *tfm)
125 {
126 struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
127
128 kfree(ctx->wmem);
129 free_page((unsigned long)ctx->sbounce);
130 free_page((unsigned long)ctx->dbounce);
131 }
132 EXPORT_SYMBOL_GPL(nx842_crypto_exit);
133
134 static void check_constraints(struct nx842_constraints *c)
135 {
136 /* limit maximum, to always have enough bounce buffer to decompress */
137 if (c->maximum > BOUNCE_BUFFER_SIZE)
138 c->maximum = BOUNCE_BUFFER_SIZE;
139 }
140
141 static int nx842_crypto_add_header(struct nx842_crypto_header *hdr, u8 *buf)
142 {
143 int s = NX842_CRYPTO_HEADER_SIZE(hdr->groups);
144
145 /* compress should have added space for header */
146 if (s > be16_to_cpu(hdr->group[0].padding)) {
147 pr_err("Internal error: no space for header\n");
148 return -EINVAL;
149 }
150
151 memcpy(buf, hdr, s);
152
153 print_hex_dump_debug("header ", DUMP_PREFIX_OFFSET, 16, 1, buf, s, 0);
154
155 return 0;
156 }
157
158 static int compress(struct nx842_crypto_ctx *ctx,
159 struct nx842_crypto_param *p,
160 struct nx842_crypto_header_group *g,
161 struct nx842_constraints *c,
162 u16 *ignore,
163 unsigned int hdrsize)
164 {
165 unsigned int slen = p->iremain, dlen = p->oremain, tmplen;
166 unsigned int adj_slen = slen;
167 u8 *src = p->in, *dst = p->out;
168 int ret, dskip = 0;
169 ktime_t timeout;
170
171 if (p->iremain == 0)
172 return -EOVERFLOW;
173
174 if (p->oremain == 0 || hdrsize + c->minimum > dlen)
175 return -ENOSPC;
176
177 if (slen % c->multiple)
178 adj_slen = round_up(slen, c->multiple);
179 if (slen < c->minimum)
180 adj_slen = c->minimum;
181 if (slen > c->maximum)
182 adj_slen = slen = c->maximum;
183 if (adj_slen > slen || (u64)src % c->alignment) {
184 adj_slen = min(adj_slen, BOUNCE_BUFFER_SIZE);
185 slen = min(slen, BOUNCE_BUFFER_SIZE);
186 if (adj_slen > slen)
187 memset(ctx->sbounce + slen, 0, adj_slen - slen);
188 memcpy(ctx->sbounce, src, slen);
189 src = ctx->sbounce;
190 slen = adj_slen;
191 pr_debug("using comp sbounce buffer, len %x\n", slen);
192 }
193
194 dst += hdrsize;
195 dlen -= hdrsize;
196
197 if ((u64)dst % c->alignment) {
198 dskip = (int)(PTR_ALIGN(dst, c->alignment) - dst);
199 dst += dskip;
200 dlen -= dskip;
201 }
202 if (dlen % c->multiple)
203 dlen = round_down(dlen, c->multiple);
204 if (dlen < c->minimum) {
205 nospc:
206 dst = ctx->dbounce;
207 dlen = min(p->oremain, BOUNCE_BUFFER_SIZE);
208 dlen = round_down(dlen, c->multiple);
209 dskip = 0;
210 pr_debug("using comp dbounce buffer, len %x\n", dlen);
211 }
212 if (dlen > c->maximum)
213 dlen = c->maximum;
214
215 tmplen = dlen;
216 timeout = ktime_add_ms(ktime_get(), COMP_BUSY_TIMEOUT);
217 do {
218 dlen = tmplen; /* reset dlen, if we're retrying */
219 ret = ctx->driver->compress(src, slen, dst, &dlen, ctx->wmem);
220 /* possibly we should reduce the slen here, instead of
221 * retrying with the dbounce buffer?
222 */
223 if (ret == -ENOSPC && dst != ctx->dbounce)
224 goto nospc;
225 } while (ret == -EBUSY && ktime_before(ktime_get(), timeout));
226 if (ret)
227 return ret;
228
229 dskip += hdrsize;
230
231 if (dst == ctx->dbounce)
232 memcpy(p->out + dskip, dst, dlen);
233
234 g->padding = cpu_to_be16(dskip);
235 g->compressed_length = cpu_to_be32(dlen);
236 g->uncompressed_length = cpu_to_be32(slen);
237
238 if (p->iremain < slen) {
239 *ignore = slen - p->iremain;
240 slen = p->iremain;
241 }
242
243 pr_debug("compress slen %x ignore %x dlen %x padding %x\n",
244 slen, *ignore, dlen, dskip);
245
246 return update_param(p, slen, dskip + dlen);
247 }
248
249 int nx842_crypto_compress(struct crypto_tfm *tfm,
250 const u8 *src, unsigned int slen,
251 u8 *dst, unsigned int *dlen)
252 {
253 struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
254 struct nx842_crypto_header *hdr = &ctx->header;
255 struct nx842_crypto_param p;
256 struct nx842_constraints c = *ctx->driver->constraints;
257 unsigned int groups, hdrsize, h;
258 int ret, n;
259 bool add_header;
260 u16 ignore = 0;
261
262 check_constraints(&c);
263
264 p.in = (u8 *)src;
265 p.iremain = slen;
266 p.out = dst;
267 p.oremain = *dlen;
268 p.ototal = 0;
269
270 *dlen = 0;
271
272 groups = min_t(unsigned int, NX842_CRYPTO_GROUP_MAX,
273 DIV_ROUND_UP(p.iremain, c.maximum));
274 hdrsize = NX842_CRYPTO_HEADER_SIZE(groups);
275
276 spin_lock_bh(&ctx->lock);
277
278 /* skip adding header if the buffers meet all constraints */
279 add_header = (p.iremain % c.multiple ||
280 p.iremain < c.minimum ||
281 p.iremain > c.maximum ||
282 (u64)p.in % c.alignment ||
283 p.oremain % c.multiple ||
284 p.oremain < c.minimum ||
285 p.oremain > c.maximum ||
286 (u64)p.out % c.alignment);
287
288 hdr->magic = cpu_to_be16(NX842_CRYPTO_MAGIC);
289 hdr->groups = 0;
290 hdr->ignore = 0;
291
292 while (p.iremain > 0) {
293 n = hdr->groups++;
294 ret = -ENOSPC;
295 if (hdr->groups > NX842_CRYPTO_GROUP_MAX)
296 goto unlock;
297
298 /* header goes before first group */
299 h = !n && add_header ? hdrsize : 0;
300
301 if (ignore)
302 pr_warn("internal error, ignore is set %x\n", ignore);
303
304 ret = compress(ctx, &p, &hdr->group[n], &c, &ignore, h);
305 if (ret)
306 goto unlock;
307 }
308
309 if (!add_header && hdr->groups > 1) {
310 pr_err("Internal error: No header but multiple groups\n");
311 ret = -EINVAL;
312 goto unlock;
313 }
314
315 /* ignore indicates the input stream needed to be padded */
316 hdr->ignore = cpu_to_be16(ignore);
317 if (ignore)
318 pr_debug("marked %d bytes as ignore\n", ignore);
319
320 if (add_header)
321 ret = nx842_crypto_add_header(hdr, dst);
322 if (ret)
323 goto unlock;
324
325 *dlen = p.ototal;
326
327 pr_debug("compress total slen %x dlen %x\n", slen, *dlen);
328
329 unlock:
330 spin_unlock_bh(&ctx->lock);
331 return ret;
332 }
333 EXPORT_SYMBOL_GPL(nx842_crypto_compress);
334
335 static int decompress(struct nx842_crypto_ctx *ctx,
336 struct nx842_crypto_param *p,
337 struct nx842_crypto_header_group *g,
338 struct nx842_constraints *c,
339 u16 ignore)
340 {
341 unsigned int slen = be32_to_cpu(g->compressed_length);
342 unsigned int required_len = be32_to_cpu(g->uncompressed_length);
343 unsigned int dlen = p->oremain, tmplen;
344 unsigned int adj_slen = slen;
345 u8 *src = p->in, *dst = p->out;
346 u16 padding = be16_to_cpu(g->padding);
347 int ret, spadding = 0;
348 ktime_t timeout;
349
350 if (!slen || !required_len)
351 return -EINVAL;
352
353 if (p->iremain <= 0 || padding + slen > p->iremain)
354 return -EOVERFLOW;
355
356 if (p->oremain <= 0 || required_len - ignore > p->oremain)
357 return -ENOSPC;
358
359 src += padding;
360
361 if (slen % c->multiple)
362 adj_slen = round_up(slen, c->multiple);
363 if (slen < c->minimum)
364 adj_slen = c->minimum;
365 if (slen > c->maximum)
366 goto usesw;
367 if (slen < adj_slen || (u64)src % c->alignment) {
368 /* we can append padding bytes because the 842 format defines
369 * an "end" template (see lib/842/842_decompress.c) and will
370 * ignore any bytes following it.
371 */
372 if (slen < adj_slen)
373 memset(ctx->sbounce + slen, 0, adj_slen - slen);
374 memcpy(ctx->sbounce, src, slen);
375 src = ctx->sbounce;
376 spadding = adj_slen - slen;
377 slen = adj_slen;
378 pr_debug("using decomp sbounce buffer, len %x\n", slen);
379 }
380
381 if (dlen % c->multiple)
382 dlen = round_down(dlen, c->multiple);
383 if (dlen < required_len || (u64)dst % c->alignment) {
384 dst = ctx->dbounce;
385 dlen = min(required_len, BOUNCE_BUFFER_SIZE);
386 pr_debug("using decomp dbounce buffer, len %x\n", dlen);
387 }
388 if (dlen < c->minimum)
389 goto usesw;
390 if (dlen > c->maximum)
391 dlen = c->maximum;
392
393 tmplen = dlen;
394 timeout = ktime_add_ms(ktime_get(), DECOMP_BUSY_TIMEOUT);
395 do {
396 dlen = tmplen; /* reset dlen, if we're retrying */
397 ret = ctx->driver->decompress(src, slen, dst, &dlen, ctx->wmem);
398 } while (ret == -EBUSY && ktime_before(ktime_get(), timeout));
399 if (ret) {
400 usesw:
401 /* reset everything, sw doesn't have constraints */
402 src = p->in + padding;
403 slen = be32_to_cpu(g->compressed_length);
404 spadding = 0;
405 dst = p->out;
406 dlen = p->oremain;
407 if (dlen < required_len) { /* have ignore bytes */
408 dst = ctx->dbounce;
409 dlen = BOUNCE_BUFFER_SIZE;
410 }
411 pr_info_ratelimited("using software 842 decompression\n");
412 ret = sw842_decompress(src, slen, dst, &dlen);
413 }
414 if (ret)
415 return ret;
416
417 slen -= spadding;
418
419 dlen -= ignore;
420 if (ignore)
421 pr_debug("ignoring last %x bytes\n", ignore);
422
423 if (dst == ctx->dbounce)
424 memcpy(p->out, dst, dlen);
425
426 pr_debug("decompress slen %x padding %x dlen %x ignore %x\n",
427 slen, padding, dlen, ignore);
428
429 return update_param(p, slen + padding, dlen);
430 }
431
432 int nx842_crypto_decompress(struct crypto_tfm *tfm,
433 const u8 *src, unsigned int slen,
434 u8 *dst, unsigned int *dlen)
435 {
436 struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
437 struct nx842_crypto_header *hdr;
438 struct nx842_crypto_param p;
439 struct nx842_constraints c = *ctx->driver->constraints;
440 int n, ret, hdr_len;
441 u16 ignore = 0;
442
443 check_constraints(&c);
444
445 p.in = (u8 *)src;
446 p.iremain = slen;
447 p.out = dst;
448 p.oremain = *dlen;
449 p.ototal = 0;
450
451 *dlen = 0;
452
453 hdr = (struct nx842_crypto_header *)src;
454
455 spin_lock_bh(&ctx->lock);
456
457 /* If it doesn't start with our header magic number, assume it's a raw
458 * 842 compressed buffer and pass it directly to the hardware driver
459 */
460 if (be16_to_cpu(hdr->magic) != NX842_CRYPTO_MAGIC) {
461 struct nx842_crypto_header_group g = {
462 .padding = 0,
463 .compressed_length = cpu_to_be32(p.iremain),
464 .uncompressed_length = cpu_to_be32(p.oremain),
465 };
466
467 ret = decompress(ctx, &p, &g, &c, 0);
468 if (ret)
469 goto unlock;
470
471 goto success;
472 }
473
474 if (!hdr->groups) {
475 pr_err("header has no groups\n");
476 ret = -EINVAL;
477 goto unlock;
478 }
479 if (hdr->groups > NX842_CRYPTO_GROUP_MAX) {
480 pr_err("header has too many groups %x, max %x\n",
481 hdr->groups, NX842_CRYPTO_GROUP_MAX);
482 ret = -EINVAL;
483 goto unlock;
484 }
485
486 hdr_len = NX842_CRYPTO_HEADER_SIZE(hdr->groups);
487 if (hdr_len > slen) {
488 ret = -EOVERFLOW;
489 goto unlock;
490 }
491
492 memcpy(&ctx->header, src, hdr_len);
493 hdr = &ctx->header;
494
495 for (n = 0; n < hdr->groups; n++) {
496 /* ignore applies to last group */
497 if (n + 1 == hdr->groups)
498 ignore = be16_to_cpu(hdr->ignore);
499
500 ret = decompress(ctx, &p, &hdr->group[n], &c, ignore);
501 if (ret)
502 goto unlock;
503 }
504
505 success:
506 *dlen = p.ototal;
507
508 pr_debug("decompress total slen %x dlen %x\n", slen, *dlen);
509
510 ret = 0;
511
512 unlock:
513 spin_unlock_bh(&ctx->lock);
514
515 return ret;
516 }
517 EXPORT_SYMBOL_GPL(nx842_crypto_decompress);
518
519 MODULE_LICENSE("GPL");
520 MODULE_DESCRIPTION("IBM PowerPC Nest (NX) 842 Hardware Compression Driver");
521 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
Linux with added FPC-III support