Dan Streetman | ed70b47 | 2015-05-07 13:49:21 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Cryptographic API for the NX-842 hardware compression. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * Copyright (C) IBM Corporation, 2011-2015 |
| 15 | * |
| 16 | * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com> |
| 17 | * Seth Jennings <sjenning@linux.vnet.ibm.com> |
| 18 | * |
| 19 | * Rewrite: Dan Streetman <ddstreet@ieee.org> |
| 20 | * |
| 21 | * This is an interface to the NX-842 compression hardware in PowerPC |
| 22 | * processors. Most of the complexity of this drvier is due to the fact that |
| 23 | * the NX-842 compression hardware requires the input and output data buffers |
| 24 | * to be specifically aligned, to be a specific multiple in length, and within |
| 25 | * specific minimum and maximum lengths. Those restrictions, provided by the |
| 26 | * nx-842 driver via nx842_constraints, mean this driver must use bounce |
| 27 | * buffers and headers to correct misaligned in or out buffers, and to split |
| 28 | * input buffers that are too large. |
| 29 | * |
| 30 | * This driver will fall back to software decompression if the hardware |
| 31 | * decompression fails, so this driver's decompression should never fail as |
| 32 | * long as the provided compressed buffer is valid. Any compressed buffer |
| 33 | * created by this driver will have a header (except ones where the input |
| 34 | * perfectly matches the constraints); so users of this driver cannot simply |
| 35 | * pass a compressed buffer created by this driver over to the 842 software |
| 36 | * decompression library. Instead, users must use this driver to decompress; |
| 37 | * if the hardware fails or is unavailable, the compressed buffer will be |
| 38 | * parsed and the header removed, and the raw 842 buffer(s) passed to the 842 |
| 39 | * software decompression library. |
| 40 | * |
| 41 | * This does not fall back to software compression, however, since the caller |
| 42 | * of this function is specifically requesting hardware compression; if the |
| 43 | * hardware compression fails, the caller can fall back to software |
| 44 | * compression, and the raw 842 compressed buffer that the software compressor |
| 45 | * creates can be passed to this driver for hardware decompression; any |
| 46 | * buffer without our specific header magic is assumed to be a raw 842 buffer |
| 47 | * and passed directly to the hardware. Note that the software compression |
| 48 | * library will produce a compressed buffer that is incompatible with the |
| 49 | * hardware decompressor if the original input buffer length is not a multiple |
| 50 | * of 8; if such a compressed buffer is passed to this driver for |
| 51 | * decompression, the hardware will reject it and this driver will then pass |
| 52 | * it over to the software library for decompression. |
| 53 | */ |
| 54 | |
| 55 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 56 | |
| 57 | #include <linux/init.h> |
| 58 | #include <linux/module.h> |
| 59 | #include <linux/crypto.h> |
| 60 | #include <linux/vmalloc.h> |
| 61 | #include <linux/nx842.h> |
| 62 | #include <linux/sw842.h> |
| 63 | #include <linux/ratelimit.h> |
| 64 | |
| 65 | /* The first 5 bits of this magic are 0x1f, which is an invalid 842 5-bit |
| 66 | * template (see lib/842/842.h), so this magic number will never appear at |
| 67 | * the start of a raw 842 compressed buffer. That is important, as any buffer |
| 68 | * passed to us without this magic is assumed to be a raw 842 compressed |
| 69 | * buffer, and passed directly to the hardware to decompress. |
| 70 | */ |
| 71 | #define NX842_CRYPTO_MAGIC (0xf842) |
| 72 | #define NX842_CRYPTO_GROUP_MAX (0x20) |
| 73 | #define NX842_CRYPTO_HEADER_SIZE(g) \ |
| 74 | (sizeof(struct nx842_crypto_header) + \ |
| 75 | sizeof(struct nx842_crypto_header_group) * (g)) |
| 76 | #define NX842_CRYPTO_HEADER_MAX_SIZE \ |
| 77 | NX842_CRYPTO_HEADER_SIZE(NX842_CRYPTO_GROUP_MAX) |
| 78 | |
| 79 | /* bounce buffer size */ |
| 80 | #define BOUNCE_BUFFER_ORDER (2) |
| 81 | #define BOUNCE_BUFFER_SIZE \ |
| 82 | ((unsigned int)(PAGE_SIZE << BOUNCE_BUFFER_ORDER)) |
| 83 | |
| 84 | /* try longer on comp because we can fallback to sw decomp if hw is busy */ |
| 85 | #define COMP_BUSY_TIMEOUT (250) /* ms */ |
| 86 | #define DECOMP_BUSY_TIMEOUT (50) /* ms */ |
| 87 | |
| 88 | struct nx842_crypto_header_group { |
| 89 | __be16 padding; /* unused bytes at start of group */ |
| 90 | __be32 compressed_length; /* compressed bytes in group */ |
| 91 | __be32 uncompressed_length; /* bytes after decompression */ |
| 92 | } __packed; |
| 93 | |
| 94 | struct nx842_crypto_header { |
| 95 | __be16 magic; /* NX842_CRYPTO_MAGIC */ |
| 96 | __be16 ignore; /* decompressed end bytes to ignore */ |
| 97 | u8 groups; /* total groups in this header */ |
| 98 | struct nx842_crypto_header_group group[]; |
| 99 | } __packed; |
| 100 | |
| 101 | struct nx842_crypto_param { |
| 102 | u8 *in; |
| 103 | unsigned int iremain; |
| 104 | u8 *out; |
| 105 | unsigned int oremain; |
| 106 | unsigned int ototal; |
| 107 | }; |
| 108 | |
| 109 | static int update_param(struct nx842_crypto_param *p, |
| 110 | unsigned int slen, unsigned int dlen) |
| 111 | { |
| 112 | if (p->iremain < slen) |
| 113 | return -EOVERFLOW; |
| 114 | if (p->oremain < dlen) |
| 115 | return -ENOSPC; |
| 116 | |
| 117 | p->in += slen; |
| 118 | p->iremain -= slen; |
| 119 | p->out += dlen; |
| 120 | p->oremain -= dlen; |
| 121 | p->ototal += dlen; |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | struct nx842_crypto_ctx { |
| 127 | u8 *wmem; |
| 128 | u8 *sbounce, *dbounce; |
| 129 | |
| 130 | struct nx842_crypto_header header; |
| 131 | struct nx842_crypto_header_group group[NX842_CRYPTO_GROUP_MAX]; |
| 132 | }; |
| 133 | |
| 134 | static int nx842_crypto_init(struct crypto_tfm *tfm) |
| 135 | { |
| 136 | struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm); |
| 137 | |
| 138 | ctx->wmem = kmalloc(NX842_MEM_COMPRESS, GFP_KERNEL); |
| 139 | ctx->sbounce = (u8 *)__get_free_pages(GFP_KERNEL, BOUNCE_BUFFER_ORDER); |
| 140 | ctx->dbounce = (u8 *)__get_free_pages(GFP_KERNEL, BOUNCE_BUFFER_ORDER); |
| 141 | if (!ctx->wmem || !ctx->sbounce || !ctx->dbounce) { |
| 142 | kfree(ctx->wmem); |
| 143 | free_page((unsigned long)ctx->sbounce); |
| 144 | free_page((unsigned long)ctx->dbounce); |
| 145 | return -ENOMEM; |
| 146 | } |
| 147 | |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | static void nx842_crypto_exit(struct crypto_tfm *tfm) |
| 152 | { |
| 153 | struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm); |
| 154 | |
| 155 | kfree(ctx->wmem); |
| 156 | free_page((unsigned long)ctx->sbounce); |
| 157 | free_page((unsigned long)ctx->dbounce); |
| 158 | } |
| 159 | |
| 160 | static int read_constraints(struct nx842_constraints *c) |
| 161 | { |
| 162 | int ret; |
| 163 | |
| 164 | ret = nx842_constraints(c); |
| 165 | if (ret) { |
| 166 | pr_err_ratelimited("could not get nx842 constraints : %d\n", |
| 167 | ret); |
| 168 | return ret; |
| 169 | } |
| 170 | |
| 171 | /* limit maximum, to always have enough bounce buffer to decompress */ |
| 172 | if (c->maximum > BOUNCE_BUFFER_SIZE) { |
| 173 | c->maximum = BOUNCE_BUFFER_SIZE; |
| 174 | pr_info_once("limiting nx842 maximum to %x\n", c->maximum); |
| 175 | } |
| 176 | |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | static int nx842_crypto_add_header(struct nx842_crypto_header *hdr, u8 *buf) |
| 181 | { |
| 182 | int s = NX842_CRYPTO_HEADER_SIZE(hdr->groups); |
| 183 | |
| 184 | /* compress should have added space for header */ |
| 185 | if (s > be16_to_cpu(hdr->group[0].padding)) { |
| 186 | pr_err("Internal error: no space for header\n"); |
| 187 | return -EINVAL; |
| 188 | } |
| 189 | |
| 190 | memcpy(buf, hdr, s); |
| 191 | |
| 192 | print_hex_dump_debug("header ", DUMP_PREFIX_OFFSET, 16, 1, buf, s, 0); |
| 193 | |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | static int compress(struct nx842_crypto_ctx *ctx, |
| 198 | struct nx842_crypto_param *p, |
| 199 | struct nx842_crypto_header_group *g, |
| 200 | struct nx842_constraints *c, |
| 201 | u16 *ignore, |
| 202 | unsigned int hdrsize) |
| 203 | { |
| 204 | unsigned int slen = p->iremain, dlen = p->oremain, tmplen; |
| 205 | unsigned int adj_slen = slen; |
| 206 | u8 *src = p->in, *dst = p->out; |
| 207 | int ret, dskip = 0; |
| 208 | ktime_t timeout; |
| 209 | |
| 210 | if (p->iremain == 0) |
| 211 | return -EOVERFLOW; |
| 212 | |
| 213 | if (p->oremain == 0 || hdrsize + c->minimum > dlen) |
| 214 | return -ENOSPC; |
| 215 | |
| 216 | if (slen % c->multiple) |
| 217 | adj_slen = round_up(slen, c->multiple); |
| 218 | if (slen < c->minimum) |
| 219 | adj_slen = c->minimum; |
| 220 | if (slen > c->maximum) |
| 221 | adj_slen = slen = c->maximum; |
| 222 | if (adj_slen > slen || (u64)src % c->alignment) { |
| 223 | adj_slen = min(adj_slen, BOUNCE_BUFFER_SIZE); |
| 224 | slen = min(slen, BOUNCE_BUFFER_SIZE); |
| 225 | if (adj_slen > slen) |
| 226 | memset(ctx->sbounce + slen, 0, adj_slen - slen); |
| 227 | memcpy(ctx->sbounce, src, slen); |
| 228 | src = ctx->sbounce; |
| 229 | slen = adj_slen; |
| 230 | pr_debug("using comp sbounce buffer, len %x\n", slen); |
| 231 | } |
| 232 | |
| 233 | dst += hdrsize; |
| 234 | dlen -= hdrsize; |
| 235 | |
| 236 | if ((u64)dst % c->alignment) { |
| 237 | dskip = (int)(PTR_ALIGN(dst, c->alignment) - dst); |
| 238 | dst += dskip; |
| 239 | dlen -= dskip; |
| 240 | } |
| 241 | if (dlen % c->multiple) |
| 242 | dlen = round_down(dlen, c->multiple); |
| 243 | if (dlen < c->minimum) { |
| 244 | nospc: |
| 245 | dst = ctx->dbounce; |
| 246 | dlen = min(p->oremain, BOUNCE_BUFFER_SIZE); |
| 247 | dlen = round_down(dlen, c->multiple); |
| 248 | dskip = 0; |
| 249 | pr_debug("using comp dbounce buffer, len %x\n", dlen); |
| 250 | } |
| 251 | if (dlen > c->maximum) |
| 252 | dlen = c->maximum; |
| 253 | |
| 254 | tmplen = dlen; |
| 255 | timeout = ktime_add_ms(ktime_get(), COMP_BUSY_TIMEOUT); |
| 256 | do { |
| 257 | dlen = tmplen; /* reset dlen, if we're retrying */ |
| 258 | ret = nx842_compress(src, slen, dst, &dlen, ctx->wmem); |
| 259 | /* possibly we should reduce the slen here, instead of |
| 260 | * retrying with the dbounce buffer? |
| 261 | */ |
| 262 | if (ret == -ENOSPC && dst != ctx->dbounce) |
| 263 | goto nospc; |
| 264 | } while (ret == -EBUSY && ktime_before(ktime_get(), timeout)); |
| 265 | if (ret) |
| 266 | return ret; |
| 267 | |
| 268 | dskip += hdrsize; |
| 269 | |
| 270 | if (dst == ctx->dbounce) |
| 271 | memcpy(p->out + dskip, dst, dlen); |
| 272 | |
| 273 | g->padding = cpu_to_be16(dskip); |
| 274 | g->compressed_length = cpu_to_be32(dlen); |
| 275 | g->uncompressed_length = cpu_to_be32(slen); |
| 276 | |
| 277 | if (p->iremain < slen) { |
| 278 | *ignore = slen - p->iremain; |
| 279 | slen = p->iremain; |
| 280 | } |
| 281 | |
| 282 | pr_debug("compress slen %x ignore %x dlen %x padding %x\n", |
| 283 | slen, *ignore, dlen, dskip); |
| 284 | |
| 285 | return update_param(p, slen, dskip + dlen); |
| 286 | } |
| 287 | |
| 288 | static int nx842_crypto_compress(struct crypto_tfm *tfm, |
| 289 | const u8 *src, unsigned int slen, |
| 290 | u8 *dst, unsigned int *dlen) |
| 291 | { |
| 292 | struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm); |
| 293 | struct nx842_crypto_header *hdr = &ctx->header; |
| 294 | struct nx842_crypto_param p; |
| 295 | struct nx842_constraints c; |
| 296 | unsigned int groups, hdrsize, h; |
| 297 | int ret, n; |
| 298 | bool add_header; |
| 299 | u16 ignore = 0; |
| 300 | |
Dan Streetman | ed70b47 | 2015-05-07 13:49:21 -0400 | [diff] [blame] | 301 | p.in = (u8 *)src; |
| 302 | p.iremain = slen; |
| 303 | p.out = dst; |
| 304 | p.oremain = *dlen; |
| 305 | p.ototal = 0; |
| 306 | |
| 307 | *dlen = 0; |
| 308 | |
| 309 | ret = read_constraints(&c); |
| 310 | if (ret) |
| 311 | return ret; |
| 312 | |
| 313 | groups = min_t(unsigned int, NX842_CRYPTO_GROUP_MAX, |
| 314 | DIV_ROUND_UP(p.iremain, c.maximum)); |
| 315 | hdrsize = NX842_CRYPTO_HEADER_SIZE(groups); |
| 316 | |
| 317 | /* skip adding header if the buffers meet all constraints */ |
| 318 | add_header = (p.iremain % c.multiple || |
| 319 | p.iremain < c.minimum || |
| 320 | p.iremain > c.maximum || |
| 321 | (u64)p.in % c.alignment || |
| 322 | p.oremain % c.multiple || |
| 323 | p.oremain < c.minimum || |
| 324 | p.oremain > c.maximum || |
| 325 | (u64)p.out % c.alignment); |
| 326 | |
| 327 | hdr->magic = cpu_to_be16(NX842_CRYPTO_MAGIC); |
| 328 | hdr->groups = 0; |
| 329 | hdr->ignore = 0; |
| 330 | |
| 331 | while (p.iremain > 0) { |
| 332 | n = hdr->groups++; |
| 333 | if (hdr->groups > NX842_CRYPTO_GROUP_MAX) |
| 334 | return -ENOSPC; |
| 335 | |
| 336 | /* header goes before first group */ |
| 337 | h = !n && add_header ? hdrsize : 0; |
| 338 | |
| 339 | if (ignore) |
| 340 | pr_warn("interal error, ignore is set %x\n", ignore); |
| 341 | |
| 342 | ret = compress(ctx, &p, &hdr->group[n], &c, &ignore, h); |
| 343 | if (ret) |
| 344 | return ret; |
| 345 | } |
| 346 | |
| 347 | if (!add_header && hdr->groups > 1) { |
| 348 | pr_err("Internal error: No header but multiple groups\n"); |
| 349 | return -EINVAL; |
| 350 | } |
| 351 | |
| 352 | /* ignore indicates the input stream needed to be padded */ |
| 353 | hdr->ignore = cpu_to_be16(ignore); |
| 354 | if (ignore) |
| 355 | pr_debug("marked %d bytes as ignore\n", ignore); |
| 356 | |
| 357 | if (add_header) |
| 358 | ret = nx842_crypto_add_header(hdr, dst); |
| 359 | if (ret) |
| 360 | return ret; |
| 361 | |
| 362 | *dlen = p.ototal; |
| 363 | |
| 364 | pr_debug("compress total slen %x dlen %x\n", slen, *dlen); |
| 365 | |
| 366 | return 0; |
| 367 | } |
| 368 | |
| 369 | static int decompress(struct nx842_crypto_ctx *ctx, |
| 370 | struct nx842_crypto_param *p, |
| 371 | struct nx842_crypto_header_group *g, |
| 372 | struct nx842_constraints *c, |
| 373 | u16 ignore, |
| 374 | bool usehw) |
| 375 | { |
| 376 | unsigned int slen = be32_to_cpu(g->compressed_length); |
| 377 | unsigned int required_len = be32_to_cpu(g->uncompressed_length); |
| 378 | unsigned int dlen = p->oremain, tmplen; |
| 379 | unsigned int adj_slen = slen; |
| 380 | u8 *src = p->in, *dst = p->out; |
| 381 | u16 padding = be16_to_cpu(g->padding); |
| 382 | int ret, spadding = 0, dpadding = 0; |
| 383 | ktime_t timeout; |
| 384 | |
| 385 | if (!slen || !required_len) |
| 386 | return -EINVAL; |
| 387 | |
| 388 | if (p->iremain <= 0 || padding + slen > p->iremain) |
| 389 | return -EOVERFLOW; |
| 390 | |
| 391 | if (p->oremain <= 0 || required_len - ignore > p->oremain) |
| 392 | return -ENOSPC; |
| 393 | |
| 394 | src += padding; |
| 395 | |
| 396 | if (!usehw) |
| 397 | goto usesw; |
| 398 | |
| 399 | if (slen % c->multiple) |
| 400 | adj_slen = round_up(slen, c->multiple); |
| 401 | if (slen < c->minimum) |
| 402 | adj_slen = c->minimum; |
| 403 | if (slen > c->maximum) |
| 404 | goto usesw; |
| 405 | if (slen < adj_slen || (u64)src % c->alignment) { |
| 406 | /* we can append padding bytes because the 842 format defines |
| 407 | * an "end" template (see lib/842/842_decompress.c) and will |
| 408 | * ignore any bytes following it. |
| 409 | */ |
| 410 | if (slen < adj_slen) |
| 411 | memset(ctx->sbounce + slen, 0, adj_slen - slen); |
| 412 | memcpy(ctx->sbounce, src, slen); |
| 413 | src = ctx->sbounce; |
| 414 | spadding = adj_slen - slen; |
| 415 | slen = adj_slen; |
| 416 | pr_debug("using decomp sbounce buffer, len %x\n", slen); |
| 417 | } |
| 418 | |
| 419 | if (dlen % c->multiple) |
| 420 | dlen = round_down(dlen, c->multiple); |
| 421 | if (dlen < required_len || (u64)dst % c->alignment) { |
| 422 | dst = ctx->dbounce; |
| 423 | dlen = min(required_len, BOUNCE_BUFFER_SIZE); |
| 424 | pr_debug("using decomp dbounce buffer, len %x\n", dlen); |
| 425 | } |
| 426 | if (dlen < c->minimum) |
| 427 | goto usesw; |
| 428 | if (dlen > c->maximum) |
| 429 | dlen = c->maximum; |
| 430 | |
| 431 | tmplen = dlen; |
| 432 | timeout = ktime_add_ms(ktime_get(), DECOMP_BUSY_TIMEOUT); |
| 433 | do { |
| 434 | dlen = tmplen; /* reset dlen, if we're retrying */ |
| 435 | ret = nx842_decompress(src, slen, dst, &dlen, ctx->wmem); |
| 436 | } while (ret == -EBUSY && ktime_before(ktime_get(), timeout)); |
| 437 | if (ret) { |
| 438 | usesw: |
| 439 | /* reset everything, sw doesn't have constraints */ |
| 440 | src = p->in + padding; |
| 441 | slen = be32_to_cpu(g->compressed_length); |
| 442 | spadding = 0; |
| 443 | dst = p->out; |
| 444 | dlen = p->oremain; |
| 445 | dpadding = 0; |
| 446 | if (dlen < required_len) { /* have ignore bytes */ |
| 447 | dst = ctx->dbounce; |
| 448 | dlen = BOUNCE_BUFFER_SIZE; |
| 449 | } |
| 450 | pr_info_ratelimited("using software 842 decompression\n"); |
| 451 | ret = sw842_decompress(src, slen, dst, &dlen); |
| 452 | } |
| 453 | if (ret) |
| 454 | return ret; |
| 455 | |
| 456 | slen -= spadding; |
| 457 | |
| 458 | dlen -= ignore; |
| 459 | if (ignore) |
| 460 | pr_debug("ignoring last %x bytes\n", ignore); |
| 461 | |
| 462 | if (dst == ctx->dbounce) |
| 463 | memcpy(p->out, dst, dlen); |
| 464 | |
| 465 | pr_debug("decompress slen %x padding %x dlen %x ignore %x\n", |
| 466 | slen, padding, dlen, ignore); |
| 467 | |
| 468 | return update_param(p, slen + padding, dlen); |
| 469 | } |
| 470 | |
| 471 | static int nx842_crypto_decompress(struct crypto_tfm *tfm, |
| 472 | const u8 *src, unsigned int slen, |
| 473 | u8 *dst, unsigned int *dlen) |
| 474 | { |
| 475 | struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm); |
| 476 | struct nx842_crypto_header *hdr; |
| 477 | struct nx842_crypto_param p; |
| 478 | struct nx842_constraints c; |
| 479 | int n, ret, hdr_len; |
| 480 | u16 ignore = 0; |
| 481 | bool usehw = true; |
| 482 | |
Dan Streetman | ed70b47 | 2015-05-07 13:49:21 -0400 | [diff] [blame] | 483 | p.in = (u8 *)src; |
| 484 | p.iremain = slen; |
| 485 | p.out = dst; |
| 486 | p.oremain = *dlen; |
| 487 | p.ototal = 0; |
| 488 | |
| 489 | *dlen = 0; |
| 490 | |
| 491 | if (read_constraints(&c)) |
| 492 | usehw = false; |
| 493 | |
| 494 | hdr = (struct nx842_crypto_header *)src; |
| 495 | |
| 496 | /* If it doesn't start with our header magic number, assume it's a raw |
| 497 | * 842 compressed buffer and pass it directly to the hardware driver |
| 498 | */ |
| 499 | if (be16_to_cpu(hdr->magic) != NX842_CRYPTO_MAGIC) { |
| 500 | struct nx842_crypto_header_group g = { |
| 501 | .padding = 0, |
| 502 | .compressed_length = cpu_to_be32(p.iremain), |
| 503 | .uncompressed_length = cpu_to_be32(p.oremain), |
| 504 | }; |
| 505 | |
| 506 | ret = decompress(ctx, &p, &g, &c, 0, usehw); |
| 507 | if (ret) |
| 508 | return ret; |
| 509 | |
| 510 | *dlen = p.ototal; |
| 511 | |
| 512 | return 0; |
| 513 | } |
| 514 | |
| 515 | if (!hdr->groups) { |
| 516 | pr_err("header has no groups\n"); |
| 517 | return -EINVAL; |
| 518 | } |
| 519 | if (hdr->groups > NX842_CRYPTO_GROUP_MAX) { |
| 520 | pr_err("header has too many groups %x, max %x\n", |
| 521 | hdr->groups, NX842_CRYPTO_GROUP_MAX); |
| 522 | return -EINVAL; |
| 523 | } |
| 524 | |
| 525 | hdr_len = NX842_CRYPTO_HEADER_SIZE(hdr->groups); |
| 526 | if (hdr_len > slen) |
| 527 | return -EOVERFLOW; |
| 528 | |
| 529 | memcpy(&ctx->header, src, hdr_len); |
| 530 | hdr = &ctx->header; |
| 531 | |
| 532 | for (n = 0; n < hdr->groups; n++) { |
| 533 | /* ignore applies to last group */ |
| 534 | if (n + 1 == hdr->groups) |
| 535 | ignore = be16_to_cpu(hdr->ignore); |
| 536 | |
| 537 | ret = decompress(ctx, &p, &hdr->group[n], &c, ignore, usehw); |
| 538 | if (ret) |
| 539 | return ret; |
| 540 | } |
| 541 | |
| 542 | *dlen = p.ototal; |
| 543 | |
| 544 | pr_debug("decompress total slen %x dlen %x\n", slen, *dlen); |
| 545 | |
| 546 | return 0; |
| 547 | } |
| 548 | |
| 549 | static struct crypto_alg alg = { |
| 550 | .cra_name = "842", |
| 551 | .cra_driver_name = "842-nx", |
| 552 | .cra_priority = 300, |
| 553 | .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, |
| 554 | .cra_ctxsize = sizeof(struct nx842_crypto_ctx), |
| 555 | .cra_module = THIS_MODULE, |
| 556 | .cra_init = nx842_crypto_init, |
| 557 | .cra_exit = nx842_crypto_exit, |
| 558 | .cra_u = { .compress = { |
| 559 | .coa_compress = nx842_crypto_compress, |
| 560 | .coa_decompress = nx842_crypto_decompress } } |
| 561 | }; |
| 562 | |
| 563 | static int __init nx842_crypto_mod_init(void) |
| 564 | { |
| 565 | return crypto_register_alg(&alg); |
| 566 | } |
| 567 | module_init(nx842_crypto_mod_init); |
| 568 | |
| 569 | static void __exit nx842_crypto_mod_exit(void) |
| 570 | { |
| 571 | crypto_unregister_alg(&alg); |
| 572 | } |
| 573 | module_exit(nx842_crypto_mod_exit); |
| 574 | |
| 575 | MODULE_LICENSE("GPL"); |
| 576 | MODULE_DESCRIPTION("IBM PowerPC Nest (NX) 842 Hardware Compression Interface"); |
| 577 | MODULE_ALIAS_CRYPTO("842"); |
| 578 | MODULE_ALIAS_CRYPTO("842-nx"); |
| 579 | MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>"); |