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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2016 Broadcom
4 */
5
6#include <linux/kernel.h>
7#include <linux/string.h>
8
9#include "util.h"
10#include "spu.h"
11#include "spum.h"
12#include "cipher.h"
13
14char *hash_alg_name[] = { "None", "md5", "sha1", "sha224", "sha256", "aes",
15 "sha384", "sha512", "sha3_224", "sha3_256", "sha3_384", "sha3_512" };
16
17char *aead_alg_name[] = { "ccm(aes)", "gcm(aes)", "authenc" };
18
19/* Assumes SPU-M messages are in big endian */
20void spum_dump_msg_hdr(u8 *buf, unsigned int buf_len)
21{
22 u8 *ptr = buf;
23 struct SPUHEADER *spuh = (struct SPUHEADER *)buf;
24 unsigned int hash_key_len = 0;
25 unsigned int hash_state_len = 0;
26 unsigned int cipher_key_len = 0;
27 unsigned int iv_len;
28 u32 pflags;
29 u32 cflags;
30 u32 ecf;
31 u32 cipher_alg;
32 u32 cipher_mode;
33 u32 cipher_type;
34 u32 hash_alg;
35 u32 hash_mode;
36 u32 hash_type;
37 u32 sctx_size; /* SCTX length in words */
38 u32 sctx_pl_len; /* SCTX payload length in bytes */
39
40 packet_log("\n");
41 packet_log("SPU Message header %p len: %u\n", buf, buf_len);
42
43 /* ========== Decode MH ========== */
44 packet_log(" MH 0x%08x\n", be32_to_cpup((__be32 *)ptr));
45 if (spuh->mh.flags & MH_SCTX_PRES)
46 packet_log(" SCTX present\n");
47 if (spuh->mh.flags & MH_BDESC_PRES)
48 packet_log(" BDESC present\n");
49 if (spuh->mh.flags & MH_MFM_PRES)
50 packet_log(" MFM present\n");
51 if (spuh->mh.flags & MH_BD_PRES)
52 packet_log(" BD present\n");
53 if (spuh->mh.flags & MH_HASH_PRES)
54 packet_log(" HASH present\n");
55 if (spuh->mh.flags & MH_SUPDT_PRES)
56 packet_log(" SUPDT present\n");
57 packet_log(" Opcode 0x%02x\n", spuh->mh.op_code);
58
59 ptr += sizeof(spuh->mh) + sizeof(spuh->emh); /* skip emh. unused */
60
61 /* ========== Decode SCTX ========== */
62 if (spuh->mh.flags & MH_SCTX_PRES) {
63 pflags = be32_to_cpu(spuh->sa.proto_flags);
64 packet_log(" SCTX[0] 0x%08x\n", pflags);
65 sctx_size = pflags & SCTX_SIZE;
66 packet_log(" Size %u words\n", sctx_size);
67
68 cflags = be32_to_cpu(spuh->sa.cipher_flags);
69 packet_log(" SCTX[1] 0x%08x\n", cflags);
70 packet_log(" Inbound:%lu (1:decrypt/vrfy 0:encrypt/auth)\n",
71 (cflags & CIPHER_INBOUND) >> CIPHER_INBOUND_SHIFT);
72 packet_log(" Order:%lu (1:AuthFirst 0:EncFirst)\n",
73 (cflags & CIPHER_ORDER) >> CIPHER_ORDER_SHIFT);
74 packet_log(" ICV_IS_512:%lx\n",
75 (cflags & ICV_IS_512) >> ICV_IS_512_SHIFT);
76 cipher_alg = (cflags & CIPHER_ALG) >> CIPHER_ALG_SHIFT;
77 cipher_mode = (cflags & CIPHER_MODE) >> CIPHER_MODE_SHIFT;
78 cipher_type = (cflags & CIPHER_TYPE) >> CIPHER_TYPE_SHIFT;
79 packet_log(" Crypto Alg:%u Mode:%u Type:%u\n",
80 cipher_alg, cipher_mode, cipher_type);
81 hash_alg = (cflags & HASH_ALG) >> HASH_ALG_SHIFT;
82 hash_mode = (cflags & HASH_MODE) >> HASH_MODE_SHIFT;
83 hash_type = (cflags & HASH_TYPE) >> HASH_TYPE_SHIFT;
84 packet_log(" Hash Alg:%x Mode:%x Type:%x\n",
85 hash_alg, hash_mode, hash_type);
86 packet_log(" UPDT_Offset:%u\n", cflags & UPDT_OFST);
87
88 ecf = be32_to_cpu(spuh->sa.ecf);
89 packet_log(" SCTX[2] 0x%08x\n", ecf);
90 packet_log(" WriteICV:%lu CheckICV:%lu ICV_SIZE:%u ",
91 (ecf & INSERT_ICV) >> INSERT_ICV_SHIFT,
92 (ecf & CHECK_ICV) >> CHECK_ICV_SHIFT,
93 (ecf & ICV_SIZE) >> ICV_SIZE_SHIFT);
94 packet_log("BD_SUPPRESS:%lu\n",
95 (ecf & BD_SUPPRESS) >> BD_SUPPRESS_SHIFT);
96 packet_log(" SCTX_IV:%lu ExplicitIV:%lu GenIV:%lu ",
97 (ecf & SCTX_IV) >> SCTX_IV_SHIFT,
98 (ecf & EXPLICIT_IV) >> EXPLICIT_IV_SHIFT,
99 (ecf & GEN_IV) >> GEN_IV_SHIFT);
100 packet_log("IV_OV_OFST:%lu EXP_IV_SIZE:%u\n",
101 (ecf & IV_OFFSET) >> IV_OFFSET_SHIFT,
102 ecf & EXP_IV_SIZE);
103
104 ptr += sizeof(struct SCTX);
105
106 if (hash_alg && hash_mode) {
107 char *name = "NONE";
108
109 switch (hash_alg) {
110 case HASH_ALG_MD5:
111 hash_key_len = 16;
112 name = "MD5";
113 break;
114 case HASH_ALG_SHA1:
115 hash_key_len = 20;
116 name = "SHA1";
117 break;
118 case HASH_ALG_SHA224:
119 hash_key_len = 28;
120 name = "SHA224";
121 break;
122 case HASH_ALG_SHA256:
123 hash_key_len = 32;
124 name = "SHA256";
125 break;
126 case HASH_ALG_SHA384:
127 hash_key_len = 48;
128 name = "SHA384";
129 break;
130 case HASH_ALG_SHA512:
131 hash_key_len = 64;
132 name = "SHA512";
133 break;
134 case HASH_ALG_AES:
135 hash_key_len = 0;
136 name = "AES";
137 break;
138 case HASH_ALG_NONE:
139 break;
140 }
141
142 packet_log(" Auth Key Type:%s Length:%u Bytes\n",
143 name, hash_key_len);
144 packet_dump(" KEY: ", ptr, hash_key_len);
145 ptr += hash_key_len;
146 } else if ((hash_alg == HASH_ALG_AES) &&
147 (hash_mode == HASH_MODE_XCBC)) {
148 char *name = "NONE";
149
150 switch (cipher_type) {
151 case CIPHER_TYPE_AES128:
152 hash_key_len = 16;
153 name = "AES128-XCBC";
154 break;
155 case CIPHER_TYPE_AES192:
156 hash_key_len = 24;
157 name = "AES192-XCBC";
158 break;
159 case CIPHER_TYPE_AES256:
160 hash_key_len = 32;
161 name = "AES256-XCBC";
162 break;
163 }
164 packet_log(" Auth Key Type:%s Length:%u Bytes\n",
165 name, hash_key_len);
166 packet_dump(" KEY: ", ptr, hash_key_len);
167 ptr += hash_key_len;
168 }
169
170 if (hash_alg && (hash_mode == HASH_MODE_NONE) &&
171 (hash_type == HASH_TYPE_UPDT)) {
172 char *name = "NONE";
173
174 switch (hash_alg) {
175 case HASH_ALG_MD5:
176 hash_state_len = 16;
177 name = "MD5";
178 break;
179 case HASH_ALG_SHA1:
180 hash_state_len = 20;
181 name = "SHA1";
182 break;
183 case HASH_ALG_SHA224:
184 hash_state_len = 32;
185 name = "SHA224";
186 break;
187 case HASH_ALG_SHA256:
188 hash_state_len = 32;
189 name = "SHA256";
190 break;
191 case HASH_ALG_SHA384:
192 hash_state_len = 48;
193 name = "SHA384";
194 break;
195 case HASH_ALG_SHA512:
196 hash_state_len = 64;
197 name = "SHA512";
198 break;
199 case HASH_ALG_AES:
200 hash_state_len = 0;
201 name = "AES";
202 break;
203 case HASH_ALG_NONE:
204 break;
205 }
206
207 packet_log(" Auth State Type:%s Length:%u Bytes\n",
208 name, hash_state_len);
209 packet_dump(" State: ", ptr, hash_state_len);
210 ptr += hash_state_len;
211 }
212
213 if (cipher_alg) {
214 char *name = "NONE";
215
216 switch (cipher_alg) {
217 case CIPHER_ALG_DES:
218 cipher_key_len = 8;
219 name = "DES";
220 break;
221 case CIPHER_ALG_3DES:
222 cipher_key_len = 24;
223 name = "3DES";
224 break;
225 case CIPHER_ALG_AES:
226 switch (cipher_type) {
227 case CIPHER_TYPE_AES128:
228 cipher_key_len = 16;
229 name = "AES128";
230 break;
231 case CIPHER_TYPE_AES192:
232 cipher_key_len = 24;
233 name = "AES192";
234 break;
235 case CIPHER_TYPE_AES256:
236 cipher_key_len = 32;
237 name = "AES256";
238 break;
239 }
240 break;
241 case CIPHER_ALG_NONE:
242 break;
243 }
244
245 packet_log(" Cipher Key Type:%s Length:%u Bytes\n",
246 name, cipher_key_len);
247
248 /* XTS has two keys */
249 if (cipher_mode == CIPHER_MODE_XTS) {
250 packet_dump(" KEY2: ", ptr, cipher_key_len);
251 ptr += cipher_key_len;
252 packet_dump(" KEY1: ", ptr, cipher_key_len);
253 ptr += cipher_key_len;
254
255 cipher_key_len *= 2;
256 } else {
257 packet_dump(" KEY: ", ptr, cipher_key_len);
258 ptr += cipher_key_len;
259 }
260
261 if (ecf & SCTX_IV) {
262 sctx_pl_len = sctx_size * sizeof(u32) -
263 sizeof(struct SCTX);
264 iv_len = sctx_pl_len -
265 (hash_key_len + hash_state_len +
266 cipher_key_len);
267 packet_log(" IV Length:%u Bytes\n", iv_len);
268 packet_dump(" IV: ", ptr, iv_len);
269 ptr += iv_len;
270 }
271 }
272 }
273
274 /* ========== Decode BDESC ========== */
275 if (spuh->mh.flags & MH_BDESC_PRES) {
276 struct BDESC_HEADER *bdesc = (struct BDESC_HEADER *)ptr;
277
278 packet_log(" BDESC[0] 0x%08x\n", be32_to_cpup((__be32 *)ptr));
279 packet_log(" OffsetMAC:%u LengthMAC:%u\n",
280 be16_to_cpu(bdesc->offset_mac),
281 be16_to_cpu(bdesc->length_mac));
282 ptr += sizeof(u32);
283
284 packet_log(" BDESC[1] 0x%08x\n", be32_to_cpup((__be32 *)ptr));
285 packet_log(" OffsetCrypto:%u LengthCrypto:%u\n",
286 be16_to_cpu(bdesc->offset_crypto),
287 be16_to_cpu(bdesc->length_crypto));
288 ptr += sizeof(u32);
289
290 packet_log(" BDESC[2] 0x%08x\n", be32_to_cpup((__be32 *)ptr));
291 packet_log(" OffsetICV:%u OffsetIV:%u\n",
292 be16_to_cpu(bdesc->offset_icv),
293 be16_to_cpu(bdesc->offset_iv));
294 ptr += sizeof(u32);
295 }
296
297 /* ========== Decode BD ========== */
298 if (spuh->mh.flags & MH_BD_PRES) {
299 struct BD_HEADER *bd = (struct BD_HEADER *)ptr;
300
301 packet_log(" BD[0] 0x%08x\n", be32_to_cpup((__be32 *)ptr));
302 packet_log(" Size:%ubytes PrevLength:%u\n",
303 be16_to_cpu(bd->size), be16_to_cpu(bd->prev_length));
304 ptr += 4;
305 }
306
307 /* Double check sanity */
308 if (buf + buf_len != ptr) {
309 packet_log(" Packet parsed incorrectly. ");
310 packet_log("buf:%p buf_len:%u buf+buf_len:%p ptr:%p\n",
311 buf, buf_len, buf + buf_len, ptr);
312 }
313
314 packet_log("\n");
315}
316
317/**
318 * spum_ns2_ctx_max_payload() - Determine the max length of the payload for a
319 * SPU message for a given cipher and hash alg context.
320 * @cipher_alg: The cipher algorithm
321 * @cipher_mode: The cipher mode
322 * @blocksize: The size of a block of data for this algo
323 *
324 * The max payload must be a multiple of the blocksize so that if a request is
325 * too large to fit in a single SPU message, the request can be broken into
326 * max_payload sized chunks. Each chunk must be a multiple of blocksize.
327 *
328 * Return: Max payload length in bytes
329 */
330u32 spum_ns2_ctx_max_payload(enum spu_cipher_alg cipher_alg,
331 enum spu_cipher_mode cipher_mode,
332 unsigned int blocksize)
333{
334 u32 max_payload = SPUM_NS2_MAX_PAYLOAD;
335 u32 excess;
336
337 /* In XTS on SPU-M, we'll need to insert tweak before input data */
338 if (cipher_mode == CIPHER_MODE_XTS)
339 max_payload -= SPU_XTS_TWEAK_SIZE;
340
341 excess = max_payload % blocksize;
342
343 return max_payload - excess;
344}
345
346/**
347 * spum_nsp_ctx_max_payload() - Determine the max length of the payload for a
348 * SPU message for a given cipher and hash alg context.
349 * @cipher_alg: The cipher algorithm
350 * @cipher_mode: The cipher mode
351 * @blocksize: The size of a block of data for this algo
352 *
353 * The max payload must be a multiple of the blocksize so that if a request is
354 * too large to fit in a single SPU message, the request can be broken into
355 * max_payload sized chunks. Each chunk must be a multiple of blocksize.
356 *
357 * Return: Max payload length in bytes
358 */
359u32 spum_nsp_ctx_max_payload(enum spu_cipher_alg cipher_alg,
360 enum spu_cipher_mode cipher_mode,
361 unsigned int blocksize)
362{
363 u32 max_payload = SPUM_NSP_MAX_PAYLOAD;
364 u32 excess;
365
366 /* In XTS on SPU-M, we'll need to insert tweak before input data */
367 if (cipher_mode == CIPHER_MODE_XTS)
368 max_payload -= SPU_XTS_TWEAK_SIZE;
369
370 excess = max_payload % blocksize;
371
372 return max_payload - excess;
373}
374
375/** spum_payload_length() - Given a SPU-M message header, extract the payload
376 * length.
377 * @spu_hdr: Start of SPU header
378 *
379 * Assumes just MH, EMH, BD (no SCTX, BDESC. Works for response frames.
380 *
381 * Return: payload length in bytes
382 */
383u32 spum_payload_length(u8 *spu_hdr)
384{
385 struct BD_HEADER *bd;
386 u32 pl_len;
387
388 /* Find BD header. skip MH, EMH */
389 bd = (struct BD_HEADER *)(spu_hdr + 8);
390 pl_len = be16_to_cpu(bd->size);
391
392 return pl_len;
393}
394
395/**
396 * spum_response_hdr_len() - Given the length of the hash key and encryption
397 * key, determine the expected length of a SPU response header.
398 * @auth_key_len: authentication key length (bytes)
399 * @enc_key_len: encryption key length (bytes)
400 * @is_hash: true if response message is for a hash operation
401 *
402 * Return: length of SPU response header (bytes)
403 */
404u16 spum_response_hdr_len(u16 auth_key_len, u16 enc_key_len, bool is_hash)
405{
406 if (is_hash)
407 return SPU_HASH_RESP_HDR_LEN;
408 else
409 return SPU_RESP_HDR_LEN;
410}
411
412/**
413 * spum_hash_pad_len() - Calculate the length of hash padding required to extend
414 * data to a full block size.
415 * @hash_alg: hash algorithm
416 * @hash_mode: hash mode
417 * @chunksize: length of data, in bytes
418 * @hash_block_size: size of a block of data for hash algorithm
419 *
420 * Reserve space for 1 byte (0x80) start of pad and the total length as u64
421 *
422 * Return: length of hash pad in bytes
423 */
424u16 spum_hash_pad_len(enum hash_alg hash_alg, enum hash_mode hash_mode,
425 u32 chunksize, u16 hash_block_size)
426{
427 unsigned int length_len;
428 unsigned int used_space_last_block;
429 int hash_pad_len;
430
431 /* AES-XCBC hash requires just padding to next block boundary */
432 if ((hash_alg == HASH_ALG_AES) && (hash_mode == HASH_MODE_XCBC)) {
433 used_space_last_block = chunksize % hash_block_size;
434 hash_pad_len = hash_block_size - used_space_last_block;
435 if (hash_pad_len >= hash_block_size)
436 hash_pad_len -= hash_block_size;
437 return hash_pad_len;
438 }
439
440 used_space_last_block = chunksize % hash_block_size + 1;
441 if ((hash_alg == HASH_ALG_SHA384) || (hash_alg == HASH_ALG_SHA512))
442 length_len = 2 * sizeof(u64);
443 else
444 length_len = sizeof(u64);
445
446 used_space_last_block += length_len;
447 hash_pad_len = hash_block_size - used_space_last_block;
448 if (hash_pad_len < 0)
449 hash_pad_len += hash_block_size;
450
451 hash_pad_len += 1 + length_len;
452 return hash_pad_len;
453}
454
455/**
456 * spum_gcm_ccm_pad_len() - Determine the required length of GCM or CCM padding.
457 * @cipher_mode: Algo type
458 * @data_size: Length of plaintext (bytes)
459 *
460 * Return: Length of padding, in bytes
461 */
462u32 spum_gcm_ccm_pad_len(enum spu_cipher_mode cipher_mode,
463 unsigned int data_size)
464{
465 u32 pad_len = 0;
466 u32 m1 = SPU_GCM_CCM_ALIGN - 1;
467
468 if ((cipher_mode == CIPHER_MODE_GCM) ||
469 (cipher_mode == CIPHER_MODE_CCM))
470 pad_len = ((data_size + m1) & ~m1) - data_size;
471
472 return pad_len;
473}
474
475/**
476 * spum_assoc_resp_len() - Determine the size of the receive buffer required to
477 * catch associated data.
478 * @cipher_mode: cipher mode
479 * @assoc_len: length of associated data (bytes)
480 * @iv_len: length of IV (bytes)
481 * @is_encrypt: true if encrypting. false if decrypting.
482 *
483 * Return: length of associated data in response message (bytes)
484 */
485u32 spum_assoc_resp_len(enum spu_cipher_mode cipher_mode,
486 unsigned int assoc_len, unsigned int iv_len,
487 bool is_encrypt)
488{
489 u32 buflen = 0;
490 u32 pad;
491
492 if (assoc_len)
493 buflen = assoc_len;
494
495 if (cipher_mode == CIPHER_MODE_GCM) {
496 /* AAD needs to be padded in responses too */
497 pad = spum_gcm_ccm_pad_len(cipher_mode, buflen);
498 buflen += pad;
499 }
500 if (cipher_mode == CIPHER_MODE_CCM) {
501 /*
502 * AAD needs to be padded in responses too
503 * for CCM, len + 2 needs to be 128-bit aligned.
504 */
505 pad = spum_gcm_ccm_pad_len(cipher_mode, buflen + 2);
506 buflen += pad;
507 }
508
509 return buflen;
510}
511
512/**
513 * spum_aead_ivlen() - Calculate the length of the AEAD IV to be included
514 * in a SPU request after the AAD and before the payload.
515 * @cipher_mode: cipher mode
516 * @iv_len: initialization vector length in bytes
517 *
518 * In Linux ~4.2 and later, the assoc_data sg includes the IV. So no need
519 * to include the IV as a separate field in the SPU request msg.
520 *
521 * Return: Length of AEAD IV in bytes
522 */
523u8 spum_aead_ivlen(enum spu_cipher_mode cipher_mode, u16 iv_len)
524{
525 return 0;
526}
527
528/**
529 * spum_hash_type() - Determine the type of hash operation.
530 * @src_sent: The number of bytes in the current request that have already
531 * been sent to the SPU to be hashed.
532 *
533 * We do not use HASH_TYPE_FULL for requests that fit in a single SPU message.
534 * Using FULL causes failures (such as when the string to be hashed is empty).
535 * For similar reasons, we never use HASH_TYPE_FIN. Instead, submit messages
536 * as INIT or UPDT and do the hash padding in sw.
537 */
538enum hash_type spum_hash_type(u32 src_sent)
539{
540 return src_sent ? HASH_TYPE_UPDT : HASH_TYPE_INIT;
541}
542
543/**
544 * spum_digest_size() - Determine the size of a hash digest to expect the SPU to
545 * return.
546 * @alg_digest_size: Number of bytes in the final digest for the given algo
547 * @alg: The hash algorithm
548 * @htype: Type of hash operation (init, update, full, etc)
549 *
550 * When doing incremental hashing for an algorithm with a truncated hash
551 * (e.g., SHA224), the SPU returns the full digest so that it can be fed back as
552 * a partial result for the next chunk.
553 */
554u32 spum_digest_size(u32 alg_digest_size, enum hash_alg alg,
555 enum hash_type htype)
556{
557 u32 digestsize = alg_digest_size;
558
559 /* SPU returns complete digest when doing incremental hash and truncated
560 * hash algo.
561 */
562 if ((htype == HASH_TYPE_INIT) || (htype == HASH_TYPE_UPDT)) {
563 if (alg == HASH_ALG_SHA224)
564 digestsize = SHA256_DIGEST_SIZE;
565 else if (alg == HASH_ALG_SHA384)
566 digestsize = SHA512_DIGEST_SIZE;
567 }
568 return digestsize;
569}
570
571/**
572 * spum_create_request() - Build a SPU request message header, up to and
573 * including the BD header. Construct the message starting at spu_hdr. Caller
574 * should allocate this buffer in DMA-able memory at least SPU_HEADER_ALLOC_LEN
575 * bytes long.
576 * @spu_hdr: Start of buffer where SPU request header is to be written
577 * @req_opts: SPU request message options
578 * @cipher_parms: Parameters related to cipher algorithm
579 * @hash_parms: Parameters related to hash algorithm
580 * @aead_parms: Parameters related to AEAD operation
581 * @data_size: Length of data to be encrypted or authenticated. If AEAD, does
582 * not include length of AAD.
583 *
584 * Return: the length of the SPU header in bytes. 0 if an error occurs.
585 */
586u32 spum_create_request(u8 *spu_hdr,
587 struct spu_request_opts *req_opts,
588 struct spu_cipher_parms *cipher_parms,
589 struct spu_hash_parms *hash_parms,
590 struct spu_aead_parms *aead_parms,
591 unsigned int data_size)
592{
593 struct SPUHEADER *spuh;
594 struct BDESC_HEADER *bdesc;
595 struct BD_HEADER *bd;
596
597 u8 *ptr;
598 u32 protocol_bits = 0;
599 u32 cipher_bits = 0;
600 u32 ecf_bits = 0;
601 u8 sctx_words = 0;
602 unsigned int buf_len = 0;
603
604 /* size of the cipher payload */
605 unsigned int cipher_len = hash_parms->prebuf_len + data_size +
606 hash_parms->pad_len;
607
608 /* offset of prebuf or data from end of BD header */
609 unsigned int cipher_offset = aead_parms->assoc_size +
610 aead_parms->iv_len + aead_parms->aad_pad_len;
611
612 /* total size of the DB data (without STAT word padding) */
613 unsigned int real_db_size = spu_real_db_size(aead_parms->assoc_size,
614 aead_parms->iv_len,
615 hash_parms->prebuf_len,
616 data_size,
617 aead_parms->aad_pad_len,
618 aead_parms->data_pad_len,
619 hash_parms->pad_len);
620
621 unsigned int auth_offset = 0;
622 unsigned int offset_iv = 0;
623
624 /* size/offset of the auth payload */
625 unsigned int auth_len;
626
627 auth_len = real_db_size;
628
629 if (req_opts->is_aead && req_opts->is_inbound)
630 cipher_len -= hash_parms->digestsize;
631
632 if (req_opts->is_aead && req_opts->is_inbound)
633 auth_len -= hash_parms->digestsize;
634
635 if ((hash_parms->alg == HASH_ALG_AES) &&
636 (hash_parms->mode == HASH_MODE_XCBC)) {
637 auth_len -= hash_parms->pad_len;
638 cipher_len -= hash_parms->pad_len;
639 }
640
641 flow_log("%s()\n", __func__);
642 flow_log(" in:%u authFirst:%u\n",
643 req_opts->is_inbound, req_opts->auth_first);
644 flow_log(" %s. cipher alg:%u mode:%u type %u\n",
645 spu_alg_name(cipher_parms->alg, cipher_parms->mode),
646 cipher_parms->alg, cipher_parms->mode, cipher_parms->type);
647 flow_log(" key: %d\n", cipher_parms->key_len);
648 flow_dump(" key: ", cipher_parms->key_buf, cipher_parms->key_len);
649 flow_log(" iv: %d\n", cipher_parms->iv_len);
650 flow_dump(" iv: ", cipher_parms->iv_buf, cipher_parms->iv_len);
651 flow_log(" auth alg:%u mode:%u type %u\n",
652 hash_parms->alg, hash_parms->mode, hash_parms->type);
653 flow_log(" digestsize: %u\n", hash_parms->digestsize);
654 flow_log(" authkey: %d\n", hash_parms->key_len);
655 flow_dump(" authkey: ", hash_parms->key_buf, hash_parms->key_len);
656 flow_log(" assoc_size:%u\n", aead_parms->assoc_size);
657 flow_log(" prebuf_len:%u\n", hash_parms->prebuf_len);
658 flow_log(" data_size:%u\n", data_size);
659 flow_log(" hash_pad_len:%u\n", hash_parms->pad_len);
660 flow_log(" real_db_size:%u\n", real_db_size);
661 flow_log(" auth_offset:%u auth_len:%u cipher_offset:%u cipher_len:%u\n",
662 auth_offset, auth_len, cipher_offset, cipher_len);
663 flow_log(" aead_iv: %u\n", aead_parms->iv_len);
664
665 /* starting out: zero the header (plus some) */
666 ptr = spu_hdr;
667 memset(ptr, 0, sizeof(struct SPUHEADER));
668
669 /* format master header word */
670 /* Do not set the next bit even though the datasheet says to */
671 spuh = (struct SPUHEADER *)ptr;
672 ptr += sizeof(struct SPUHEADER);
673 buf_len += sizeof(struct SPUHEADER);
674
675 spuh->mh.op_code = SPU_CRYPTO_OPERATION_GENERIC;
676 spuh->mh.flags |= (MH_SCTX_PRES | MH_BDESC_PRES | MH_BD_PRES);
677
678 /* Format sctx word 0 (protocol_bits) */
679 sctx_words = 3; /* size in words */
680
681 /* Format sctx word 1 (cipher_bits) */
682 if (req_opts->is_inbound)
683 cipher_bits |= CIPHER_INBOUND;
684 if (req_opts->auth_first)
685 cipher_bits |= CIPHER_ORDER;
686
687 /* Set the crypto parameters in the cipher.flags */
688 cipher_bits |= cipher_parms->alg << CIPHER_ALG_SHIFT;
689 cipher_bits |= cipher_parms->mode << CIPHER_MODE_SHIFT;
690 cipher_bits |= cipher_parms->type << CIPHER_TYPE_SHIFT;
691
692 /* Set the auth parameters in the cipher.flags */
693 cipher_bits |= hash_parms->alg << HASH_ALG_SHIFT;
694 cipher_bits |= hash_parms->mode << HASH_MODE_SHIFT;
695 cipher_bits |= hash_parms->type << HASH_TYPE_SHIFT;
696
697 /*
698 * Format sctx extensions if required, and update main fields if
699 * required)
700 */
701 if (hash_parms->alg) {
702 /* Write the authentication key material if present */
703 if (hash_parms->key_len) {
704 memcpy(ptr, hash_parms->key_buf, hash_parms->key_len);
705 ptr += hash_parms->key_len;
706 buf_len += hash_parms->key_len;
707 sctx_words += hash_parms->key_len / 4;
708 }
709
710 if ((cipher_parms->mode == CIPHER_MODE_GCM) ||
711 (cipher_parms->mode == CIPHER_MODE_CCM))
712 /* unpadded length */
713 offset_iv = aead_parms->assoc_size;
714
715 /* if GCM/CCM we need to write ICV into the payload */
716 if (!req_opts->is_inbound) {
717 if ((cipher_parms->mode == CIPHER_MODE_GCM) ||
718 (cipher_parms->mode == CIPHER_MODE_CCM))
719 ecf_bits |= 1 << INSERT_ICV_SHIFT;
720 } else {
721 ecf_bits |= CHECK_ICV;
722 }
723
724 /* Inform the SPU of the ICV size (in words) */
725 if (hash_parms->digestsize == 64)
726 cipher_bits |= ICV_IS_512;
727 else
728 ecf_bits |=
729 (hash_parms->digestsize / 4) << ICV_SIZE_SHIFT;
730 }
731
732 if (req_opts->bd_suppress)
733 ecf_bits |= BD_SUPPRESS;
734
735 /* copy the encryption keys in the SAD entry */
736 if (cipher_parms->alg) {
737 if (cipher_parms->key_len) {
738 memcpy(ptr, cipher_parms->key_buf,
739 cipher_parms->key_len);
740 ptr += cipher_parms->key_len;
741 buf_len += cipher_parms->key_len;
742 sctx_words += cipher_parms->key_len / 4;
743 }
744
745 /*
746 * if encrypting then set IV size, use SCTX IV unless no IV
747 * given here
748 */
749 if (cipher_parms->iv_buf && cipher_parms->iv_len) {
750 /* Use SCTX IV */
751 ecf_bits |= SCTX_IV;
752
753 /* cipher iv provided so put it in here */
754 memcpy(ptr, cipher_parms->iv_buf, cipher_parms->iv_len);
755
756 ptr += cipher_parms->iv_len;
757 buf_len += cipher_parms->iv_len;
758 sctx_words += cipher_parms->iv_len / 4;
759 }
760 }
761
762 /*
763 * RFC4543 (GMAC/ESP) requires data to be sent as part of AAD
764 * so we need to override the BDESC parameters.
765 */
766 if (req_opts->is_rfc4543) {
767 if (req_opts->is_inbound)
768 data_size -= hash_parms->digestsize;
769 offset_iv = aead_parms->assoc_size + data_size;
770 cipher_len = 0;
771 cipher_offset = offset_iv;
772 auth_len = cipher_offset + aead_parms->data_pad_len;
773 }
774
775 /* write in the total sctx length now that we know it */
776 protocol_bits |= sctx_words;
777
778 /* Endian adjust the SCTX */
779 spuh->sa.proto_flags = cpu_to_be32(protocol_bits);
780 spuh->sa.cipher_flags = cpu_to_be32(cipher_bits);
781 spuh->sa.ecf = cpu_to_be32(ecf_bits);
782
783 /* === create the BDESC section === */
784 bdesc = (struct BDESC_HEADER *)ptr;
785
786 bdesc->offset_mac = cpu_to_be16(auth_offset);
787 bdesc->length_mac = cpu_to_be16(auth_len);
788 bdesc->offset_crypto = cpu_to_be16(cipher_offset);
789 bdesc->length_crypto = cpu_to_be16(cipher_len);
790
791 /*
792 * CCM in SPU-M requires that ICV not be in same 32-bit word as data or
793 * padding. So account for padding as necessary.
794 */
795 if (cipher_parms->mode == CIPHER_MODE_CCM)
796 auth_len += spum_wordalign_padlen(auth_len);
797
798 bdesc->offset_icv = cpu_to_be16(auth_len);
799 bdesc->offset_iv = cpu_to_be16(offset_iv);
800
801 ptr += sizeof(struct BDESC_HEADER);
802 buf_len += sizeof(struct BDESC_HEADER);
803
804 /* === no MFM section === */
805
806 /* === create the BD section === */
807
808 /* add the BD header */
809 bd = (struct BD_HEADER *)ptr;
810 bd->size = cpu_to_be16(real_db_size);
811 bd->prev_length = 0;
812
813 ptr += sizeof(struct BD_HEADER);
814 buf_len += sizeof(struct BD_HEADER);
815
816 packet_dump(" SPU request header: ", spu_hdr, buf_len);
817
818 return buf_len;
819}
820
821/**
822 * spum_cipher_req_init() - Build a SPU request message header, up to and
823 * including the BD header.
824 * @spu_hdr: Start of SPU request header (MH)
825 * @cipher_parms: Parameters that describe the cipher request
826 *
827 * Construct the message starting at spu_hdr. Caller should allocate this buffer
828 * in DMA-able memory at least SPU_HEADER_ALLOC_LEN bytes long.
829 *
830 * Return: the length of the SPU header in bytes. 0 if an error occurs.
831 */
832u16 spum_cipher_req_init(u8 *spu_hdr, struct spu_cipher_parms *cipher_parms)
833{
834 struct SPUHEADER *spuh;
835 u32 protocol_bits = 0;
836 u32 cipher_bits = 0;
837 u32 ecf_bits = 0;
838 u8 sctx_words = 0;
839 u8 *ptr = spu_hdr;
840
841 flow_log("%s()\n", __func__);
842 flow_log(" cipher alg:%u mode:%u type %u\n", cipher_parms->alg,
843 cipher_parms->mode, cipher_parms->type);
844 flow_log(" cipher_iv_len: %u\n", cipher_parms->iv_len);
845 flow_log(" key: %d\n", cipher_parms->key_len);
846 flow_dump(" key: ", cipher_parms->key_buf, cipher_parms->key_len);
847
848 /* starting out: zero the header (plus some) */
849 memset(spu_hdr, 0, sizeof(struct SPUHEADER));
850 ptr += sizeof(struct SPUHEADER);
851
852 /* format master header word */
853 /* Do not set the next bit even though the datasheet says to */
854 spuh = (struct SPUHEADER *)spu_hdr;
855
856 spuh->mh.op_code = SPU_CRYPTO_OPERATION_GENERIC;
857 spuh->mh.flags |= (MH_SCTX_PRES | MH_BDESC_PRES | MH_BD_PRES);
858
859 /* Format sctx word 0 (protocol_bits) */
860 sctx_words = 3; /* size in words */
861
862 /* copy the encryption keys in the SAD entry */
863 if (cipher_parms->alg) {
864 if (cipher_parms->key_len) {
865 ptr += cipher_parms->key_len;
866 sctx_words += cipher_parms->key_len / 4;
867 }
868
869 /*
870 * if encrypting then set IV size, use SCTX IV unless no IV
871 * given here
872 */
873 if (cipher_parms->iv_len) {
874 /* Use SCTX IV */
875 ecf_bits |= SCTX_IV;
876 ptr += cipher_parms->iv_len;
877 sctx_words += cipher_parms->iv_len / 4;
878 }
879 }
880
881 /* Set the crypto parameters in the cipher.flags */
882 cipher_bits |= cipher_parms->alg << CIPHER_ALG_SHIFT;
883 cipher_bits |= cipher_parms->mode << CIPHER_MODE_SHIFT;
884 cipher_bits |= cipher_parms->type << CIPHER_TYPE_SHIFT;
885
886 /* copy the encryption keys in the SAD entry */
887 if (cipher_parms->alg && cipher_parms->key_len)
888 memcpy(spuh + 1, cipher_parms->key_buf, cipher_parms->key_len);
889
890 /* write in the total sctx length now that we know it */
891 protocol_bits |= sctx_words;
892
893 /* Endian adjust the SCTX */
894 spuh->sa.proto_flags = cpu_to_be32(protocol_bits);
895
896 /* Endian adjust the SCTX */
897 spuh->sa.cipher_flags = cpu_to_be32(cipher_bits);
898 spuh->sa.ecf = cpu_to_be32(ecf_bits);
899
900 packet_dump(" SPU request header: ", spu_hdr,
901 sizeof(struct SPUHEADER));
902
903 return sizeof(struct SPUHEADER) + cipher_parms->key_len +
904 cipher_parms->iv_len + sizeof(struct BDESC_HEADER) +
905 sizeof(struct BD_HEADER);
906}
907
908/**
909 * spum_cipher_req_finish() - Finish building a SPU request message header for a
910 * block cipher request. Assumes much of the header was already filled in at
911 * setkey() time in spu_cipher_req_init().
912 * @spu_hdr: Start of the request message header (MH field)
913 * @spu_req_hdr_len: Length in bytes of the SPU request header
914 * @is_inbound: 0 encrypt, 1 decrypt
915 * @cipher_parms: Parameters describing cipher operation to be performed
916 * @data_size: Length of the data in the BD field
917 *
918 * Assumes much of the header was already filled in at setkey() time in
919 * spum_cipher_req_init().
920 * spum_cipher_req_init() fills in the encryption key.
921 */
922void spum_cipher_req_finish(u8 *spu_hdr,
923 u16 spu_req_hdr_len,
924 unsigned int is_inbound,
925 struct spu_cipher_parms *cipher_parms,
926 unsigned int data_size)
927{
928 struct SPUHEADER *spuh;
929 struct BDESC_HEADER *bdesc;
930 struct BD_HEADER *bd;
931 u8 *bdesc_ptr = spu_hdr + spu_req_hdr_len -
932 (sizeof(struct BD_HEADER) + sizeof(struct BDESC_HEADER));
933
934 u32 cipher_bits;
935
936 flow_log("%s()\n", __func__);
937 flow_log(" in: %u\n", is_inbound);
938 flow_log(" cipher alg: %u, cipher_type: %u\n", cipher_parms->alg,
939 cipher_parms->type);
940
941 /*
942 * In XTS mode, API puts "i" parameter (block tweak) in IV. For
943 * SPU-M, should be in start of the BD; tx_sg_create() copies it there.
944 * IV in SPU msg for SPU-M should be 0, since that's the "j" parameter
945 * (block ctr within larger data unit) - given we can send entire disk
946 * block (<= 4KB) in 1 SPU msg, don't need to use this parameter.
947 */
948 if (cipher_parms->mode == CIPHER_MODE_XTS)
949 memset(cipher_parms->iv_buf, 0, cipher_parms->iv_len);
950
951 flow_log(" iv len: %d\n", cipher_parms->iv_len);
952 flow_dump(" iv: ", cipher_parms->iv_buf, cipher_parms->iv_len);
953 flow_log(" data_size: %u\n", data_size);
954
955 /* format master header word */
956 /* Do not set the next bit even though the datasheet says to */
957 spuh = (struct SPUHEADER *)spu_hdr;
958
959 /* cipher_bits was initialized at setkey time */
960 cipher_bits = be32_to_cpu(spuh->sa.cipher_flags);
961
962 /* Format sctx word 1 (cipher_bits) */
963 if (is_inbound)
964 cipher_bits |= CIPHER_INBOUND;
965 else
966 cipher_bits &= ~CIPHER_INBOUND;
967
968 if (cipher_parms->alg && cipher_parms->iv_buf && cipher_parms->iv_len)
969 /* cipher iv provided so put it in here */
970 memcpy(bdesc_ptr - cipher_parms->iv_len, cipher_parms->iv_buf,
971 cipher_parms->iv_len);
972
973 spuh->sa.cipher_flags = cpu_to_be32(cipher_bits);
974
975 /* === create the BDESC section === */
976 bdesc = (struct BDESC_HEADER *)bdesc_ptr;
977 bdesc->offset_mac = 0;
978 bdesc->length_mac = 0;
979 bdesc->offset_crypto = 0;
980
981 /* XTS mode, data_size needs to include tweak parameter */
982 if (cipher_parms->mode == CIPHER_MODE_XTS)
983 bdesc->length_crypto = cpu_to_be16(data_size +
984 SPU_XTS_TWEAK_SIZE);
985 else
986 bdesc->length_crypto = cpu_to_be16(data_size);
987
988 bdesc->offset_icv = 0;
989 bdesc->offset_iv = 0;
990
991 /* === no MFM section === */
992
993 /* === create the BD section === */
994 /* add the BD header */
995 bd = (struct BD_HEADER *)(bdesc_ptr + sizeof(struct BDESC_HEADER));
996 bd->size = cpu_to_be16(data_size);
997
998 /* XTS mode, data_size needs to include tweak parameter */
999 if (cipher_parms->mode == CIPHER_MODE_XTS)
1000 bd->size = cpu_to_be16(data_size + SPU_XTS_TWEAK_SIZE);
1001 else
1002 bd->size = cpu_to_be16(data_size);
1003
1004 bd->prev_length = 0;
1005
1006 packet_dump(" SPU request header: ", spu_hdr, spu_req_hdr_len);
1007}
1008
1009/**
1010 * spum_request_pad() - Create pad bytes at the end of the data.
1011 * @pad_start: Start of buffer where pad bytes are to be written
1012 * @gcm_ccm_padding: length of GCM/CCM padding, in bytes
1013 * @hash_pad_len: Number of bytes of padding extend data to full block
1014 * @auth_alg: authentication algorithm
1015 * @auth_mode: authentication mode
1016 * @total_sent: length inserted at end of hash pad
1017 * @status_padding: Number of bytes of padding to align STATUS word
1018 *
1019 * There may be three forms of pad:
1020 * 1. GCM/CCM pad - for GCM/CCM mode ciphers, pad to 16-byte alignment
1021 * 2. hash pad - pad to a block length, with 0x80 data terminator and
1022 * size at the end
1023 * 3. STAT pad - to ensure the STAT field is 4-byte aligned
1024 */
1025void spum_request_pad(u8 *pad_start,
1026 u32 gcm_ccm_padding,
1027 u32 hash_pad_len,
1028 enum hash_alg auth_alg,
1029 enum hash_mode auth_mode,
1030 unsigned int total_sent, u32 status_padding)
1031{
1032 u8 *ptr = pad_start;
1033
1034 /* fix data alignent for GCM/CCM */
1035 if (gcm_ccm_padding > 0) {
1036 flow_log(" GCM: padding to 16 byte alignment: %u bytes\n",
1037 gcm_ccm_padding);
1038 memset(ptr, 0, gcm_ccm_padding);
1039 ptr += gcm_ccm_padding;
1040 }
1041
1042 if (hash_pad_len > 0) {
1043 /* clear the padding section */
1044 memset(ptr, 0, hash_pad_len);
1045
1046 if ((auth_alg == HASH_ALG_AES) &&
1047 (auth_mode == HASH_MODE_XCBC)) {
1048 /* AES/XCBC just requires padding to be 0s */
1049 ptr += hash_pad_len;
1050 } else {
1051 /* terminate the data */
1052 *ptr = 0x80;
1053 ptr += (hash_pad_len - sizeof(u64));
1054
1055 /* add the size at the end as required per alg */
1056 if (auth_alg == HASH_ALG_MD5)
1057 *(__le64 *)ptr = cpu_to_le64(total_sent * 8ull);
1058 else /* SHA1, SHA2-224, SHA2-256 */
1059 *(__be64 *)ptr = cpu_to_be64(total_sent * 8ull);
1060 ptr += sizeof(u64);
1061 }
1062 }
1063
1064 /* pad to a 4byte alignment for STAT */
1065 if (status_padding > 0) {
1066 flow_log(" STAT: padding to 4 byte alignment: %u bytes\n",
1067 status_padding);
1068
1069 memset(ptr, 0, status_padding);
1070 ptr += status_padding;
1071 }
1072}
1073
1074/**
1075 * spum_xts_tweak_in_payload() - Indicate that SPUM DOES place the XTS tweak
1076 * field in the packet payload (rather than using IV)
1077 *
1078 * Return: 1
1079 */
1080u8 spum_xts_tweak_in_payload(void)
1081{
1082 return 1;
1083}
1084
1085/**
1086 * spum_tx_status_len() - Return the length of the STATUS field in a SPU
1087 * response message.
1088 *
1089 * Return: Length of STATUS field in bytes.
1090 */
1091u8 spum_tx_status_len(void)
1092{
1093 return SPU_TX_STATUS_LEN;
1094}
1095
1096/**
1097 * spum_rx_status_len() - Return the length of the STATUS field in a SPU
1098 * response message.
1099 *
1100 * Return: Length of STATUS field in bytes.
1101 */
1102u8 spum_rx_status_len(void)
1103{
1104 return SPU_RX_STATUS_LEN;
1105}
1106
1107/**
1108 * spum_status_process() - Process the status from a SPU response message.
1109 * @statp: start of STATUS word
1110 * Return:
1111 * 0 - if status is good and response should be processed
1112 * !0 - status indicates an error and response is invalid
1113 */
1114int spum_status_process(u8 *statp)
1115{
1116 u32 status;
1117
1118 status = __be32_to_cpu(*(__be32 *)statp);
1119 flow_log("SPU response STATUS %#08x\n", status);
1120 if (status & SPU_STATUS_ERROR_FLAG) {
1121 pr_err("%s() Warning: Error result from SPU: %#08x\n",
1122 __func__, status);
1123 if (status & SPU_STATUS_INVALID_ICV)
1124 return SPU_INVALID_ICV;
1125 return -EBADMSG;
1126 }
1127 return 0;
1128}
1129
1130/**
1131 * spum_ccm_update_iv() - Update the IV as per the requirements for CCM mode.
1132 *
1133 * @digestsize: Digest size of this request
1134 * @cipher_parms: (pointer to) cipher parmaeters, includes IV buf & IV len
1135 * @assoclen: Length of AAD data
1136 * @chunksize: length of input data to be sent in this req
1137 * @is_encrypt: true if this is an output/encrypt operation
1138 * @is_esp: true if this is an ESP / RFC4309 operation
1139 *
1140 */
1141void spum_ccm_update_iv(unsigned int digestsize,
1142 struct spu_cipher_parms *cipher_parms,
1143 unsigned int assoclen,
1144 unsigned int chunksize,
1145 bool is_encrypt,
1146 bool is_esp)
1147{
1148 u8 L; /* L from CCM algorithm, length of plaintext data */
1149 u8 mprime; /* M' from CCM algo, (M - 2) / 2, where M=authsize */
1150 u8 adata;
1151
1152 if (cipher_parms->iv_len != CCM_AES_IV_SIZE) {
1153 pr_err("%s(): Invalid IV len %d for CCM mode, should be %d\n",
1154 __func__, cipher_parms->iv_len, CCM_AES_IV_SIZE);
1155 return;
1156 }
1157
1158 /*
1159 * IV needs to be formatted as follows:
1160 *
1161 * | Byte 0 | Bytes 1 - N | Bytes (N+1) - 15 |
1162 * | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Bits 7 - 0 | Bits 7 - 0 |
1163 * | 0 |Ad?|(M - 2) / 2| L - 1 | Nonce | Plaintext Length |
1164 *
1165 * Ad? = 1 if AAD present, 0 if not present
1166 * M = size of auth field, 8, 12, or 16 bytes (SPU-M) -or-
1167 * 4, 6, 8, 10, 12, 14, 16 bytes (SPU2)
1168 * L = Size of Plaintext Length field; Nonce size = 15 - L
1169 *
1170 * It appears that the crypto API already expects the L-1 portion
1171 * to be set in the first byte of the IV, which implicitly determines
1172 * the nonce size, and also fills in the nonce. But the other bits
1173 * in byte 0 as well as the plaintext length need to be filled in.
1174 *
1175 * In rfc4309/esp mode, L is not already in the supplied IV and
1176 * we need to fill it in, as well as move the IV data to be after
1177 * the salt
1178 */
1179 if (is_esp) {
1180 L = CCM_ESP_L_VALUE; /* RFC4309 has fixed L */
1181 } else {
1182 /* L' = plaintext length - 1 so Plaintext length is L' + 1 */
1183 L = ((cipher_parms->iv_buf[0] & CCM_B0_L_PRIME) >>
1184 CCM_B0_L_PRIME_SHIFT) + 1;
1185 }
1186
1187 mprime = (digestsize - 2) >> 1; /* M' = (M - 2) / 2 */
1188 adata = (assoclen > 0); /* adata = 1 if any associated data */
1189
1190 cipher_parms->iv_buf[0] = (adata << CCM_B0_ADATA_SHIFT) |
1191 (mprime << CCM_B0_M_PRIME_SHIFT) |
1192 ((L - 1) << CCM_B0_L_PRIME_SHIFT);
1193
1194 /* Nonce is already filled in by crypto API, and is 15 - L bytes */
1195
1196 /* Don't include digest in plaintext size when decrypting */
1197 if (!is_encrypt)
1198 chunksize -= digestsize;
1199
1200 /* Fill in length of plaintext, formatted to be L bytes long */
1201 format_value_ccm(chunksize, &cipher_parms->iv_buf[15 - L + 1], L);
1202}
1203
1204/**
1205 * spum_wordalign_padlen() - Given the length of a data field, determine the
1206 * padding required to align the data following this field on a 4-byte boundary.
1207 * @data_size: length of data field in bytes
1208 *
1209 * Return: length of status field padding, in bytes
1210 */
1211u32 spum_wordalign_padlen(u32 data_size)
1212{
1213 return ((data_size + 3) & ~3) - data_size;
1214}