xref: /kernel/linux/linux-5.10/drivers/crypto/bcm/spu.c (revision 8c2ecf20)
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_cpu(*((u32 *)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#ifdef DEBUG
277		struct BDESC_HEADER *bdesc = (struct BDESC_HEADER *)ptr;
278#endif
279		packet_log("  BDESC[0] 0x%08x\n", be32_to_cpu(*((u32 *)ptr)));
280		packet_log("    OffsetMAC:%u LengthMAC:%u\n",
281			   be16_to_cpu(bdesc->offset_mac),
282			   be16_to_cpu(bdesc->length_mac));
283		ptr += sizeof(u32);
284
285		packet_log("  BDESC[1] 0x%08x\n", be32_to_cpu(*((u32 *)ptr)));
286		packet_log("    OffsetCrypto:%u LengthCrypto:%u\n",
287			   be16_to_cpu(bdesc->offset_crypto),
288			   be16_to_cpu(bdesc->length_crypto));
289		ptr += sizeof(u32);
290
291		packet_log("  BDESC[2] 0x%08x\n", be32_to_cpu(*((u32 *)ptr)));
292		packet_log("    OffsetICV:%u OffsetIV:%u\n",
293			   be16_to_cpu(bdesc->offset_icv),
294			   be16_to_cpu(bdesc->offset_iv));
295		ptr += sizeof(u32);
296	}
297
298	/* ========== Decode BD ========== */
299	if (spuh->mh.flags & MH_BD_PRES) {
300#ifdef DEBUG
301		struct BD_HEADER *bd = (struct BD_HEADER *)ptr;
302#endif
303		packet_log("  BD[0] 0x%08x\n", be32_to_cpu(*((u32 *)ptr)));
304		packet_log("    Size:%ubytes PrevLength:%u\n",
305			   be16_to_cpu(bd->size), be16_to_cpu(bd->prev_length));
306		ptr += 4;
307	}
308
309	/* Double check sanity */
310	if (buf + buf_len != ptr) {
311		packet_log(" Packet parsed incorrectly. ");
312		packet_log("buf:%p buf_len:%u buf+buf_len:%p ptr:%p\n",
313			   buf, buf_len, buf + buf_len, ptr);
314	}
315
316	packet_log("\n");
317}
318
319/**
320 * spum_ns2_ctx_max_payload() - Determine the max length of the payload for a
321 * SPU message for a given cipher and hash alg context.
322 * @cipher_alg:		The cipher algorithm
323 * @cipher_mode:	The cipher mode
324 * @blocksize:		The size of a block of data for this algo
325 *
326 * The max payload must be a multiple of the blocksize so that if a request is
327 * too large to fit in a single SPU message, the request can be broken into
328 * max_payload sized chunks. Each chunk must be a multiple of blocksize.
329 *
330 * Return: Max payload length in bytes
331 */
332u32 spum_ns2_ctx_max_payload(enum spu_cipher_alg cipher_alg,
333			     enum spu_cipher_mode cipher_mode,
334			     unsigned int blocksize)
335{
336	u32 max_payload = SPUM_NS2_MAX_PAYLOAD;
337	u32 excess;
338
339	/* In XTS on SPU-M, we'll need to insert tweak before input data */
340	if (cipher_mode == CIPHER_MODE_XTS)
341		max_payload -= SPU_XTS_TWEAK_SIZE;
342
343	excess = max_payload % blocksize;
344
345	return max_payload - excess;
346}
347
348/**
349 * spum_nsp_ctx_max_payload() - Determine the max length of the payload for a
350 * SPU message for a given cipher and hash alg context.
351 * @cipher_alg:		The cipher algorithm
352 * @cipher_mode:	The cipher mode
353 * @blocksize:		The size of a block of data for this algo
354 *
355 * The max payload must be a multiple of the blocksize so that if a request is
356 * too large to fit in a single SPU message, the request can be broken into
357 * max_payload sized chunks. Each chunk must be a multiple of blocksize.
358 *
359 * Return: Max payload length in bytes
360 */
361u32 spum_nsp_ctx_max_payload(enum spu_cipher_alg cipher_alg,
362			     enum spu_cipher_mode cipher_mode,
363			     unsigned int blocksize)
364{
365	u32 max_payload = SPUM_NSP_MAX_PAYLOAD;
366	u32 excess;
367
368	/* In XTS on SPU-M, we'll need to insert tweak before input data */
369	if (cipher_mode == CIPHER_MODE_XTS)
370		max_payload -= SPU_XTS_TWEAK_SIZE;
371
372	excess = max_payload % blocksize;
373
374	return max_payload - excess;
375}
376
377/** spum_payload_length() - Given a SPU-M message header, extract the payload
378 * length.
379 * @spu_hdr:	Start of SPU header
380 *
381 * Assumes just MH, EMH, BD (no SCTX, BDESC. Works for response frames.
382 *
383 * Return: payload length in bytes
384 */
385u32 spum_payload_length(u8 *spu_hdr)
386{
387	struct BD_HEADER *bd;
388	u32 pl_len;
389
390	/* Find BD header.  skip MH, EMH */
391	bd = (struct BD_HEADER *)(spu_hdr + 8);
392	pl_len = be16_to_cpu(bd->size);
393
394	return pl_len;
395}
396
397/**
398 * spum_response_hdr_len() - Given the length of the hash key and encryption
399 * key, determine the expected length of a SPU response header.
400 * @auth_key_len:	authentication key length (bytes)
401 * @enc_key_len:	encryption key length (bytes)
402 * @is_hash:		true if response message is for a hash operation
403 *
404 * Return: length of SPU response header (bytes)
405 */
406u16 spum_response_hdr_len(u16 auth_key_len, u16 enc_key_len, bool is_hash)
407{
408	if (is_hash)
409		return SPU_HASH_RESP_HDR_LEN;
410	else
411		return SPU_RESP_HDR_LEN;
412}
413
414/**
415 * spum_hash_pad_len() - Calculate the length of hash padding required to extend
416 * data to a full block size.
417 * @hash_alg:   hash algorithm
418 * @hash_mode:       hash mode
419 * @chunksize:  length of data, in bytes
420 * @hash_block_size:  size of a block of data for hash algorithm
421 *
422 * Reserve space for 1 byte (0x80) start of pad and the total length as u64
423 *
424 * Return:  length of hash pad in bytes
425 */
426u16 spum_hash_pad_len(enum hash_alg hash_alg, enum hash_mode hash_mode,
427		      u32 chunksize, u16 hash_block_size)
428{
429	unsigned int length_len;
430	unsigned int used_space_last_block;
431	int hash_pad_len;
432
433	/* AES-XCBC hash requires just padding to next block boundary */
434	if ((hash_alg == HASH_ALG_AES) && (hash_mode == HASH_MODE_XCBC)) {
435		used_space_last_block = chunksize % hash_block_size;
436		hash_pad_len = hash_block_size - used_space_last_block;
437		if (hash_pad_len >= hash_block_size)
438			hash_pad_len -= hash_block_size;
439		return hash_pad_len;
440	}
441
442	used_space_last_block = chunksize % hash_block_size + 1;
443	if ((hash_alg == HASH_ALG_SHA384) || (hash_alg == HASH_ALG_SHA512))
444		length_len = 2 * sizeof(u64);
445	else
446		length_len = sizeof(u64);
447
448	used_space_last_block += length_len;
449	hash_pad_len = hash_block_size - used_space_last_block;
450	if (hash_pad_len < 0)
451		hash_pad_len += hash_block_size;
452
453	hash_pad_len += 1 + length_len;
454	return hash_pad_len;
455}
456
457/**
458 * spum_gcm_ccm_pad_len() - Determine the required length of GCM or CCM padding.
459 * @cipher_mode:	Algo type
460 * @data_size:		Length of plaintext (bytes)
461 *
462 * @Return: Length of padding, in bytes
463 */
464u32 spum_gcm_ccm_pad_len(enum spu_cipher_mode cipher_mode,
465			 unsigned int data_size)
466{
467	u32 pad_len = 0;
468	u32 m1 = SPU_GCM_CCM_ALIGN - 1;
469
470	if ((cipher_mode == CIPHER_MODE_GCM) ||
471	    (cipher_mode == CIPHER_MODE_CCM))
472		pad_len = ((data_size + m1) & ~m1) - data_size;
473
474	return pad_len;
475}
476
477/**
478 * spum_assoc_resp_len() - Determine the size of the receive buffer required to
479 * catch associated data.
480 * @cipher_mode:	cipher mode
481 * @assoc_len:		length of associated data (bytes)
482 * @iv_len:		length of IV (bytes)
483 * @is_encrypt:		true if encrypting. false if decrypting.
484 *
485 * Return: length of associated data in response message (bytes)
486 */
487u32 spum_assoc_resp_len(enum spu_cipher_mode cipher_mode,
488			unsigned int assoc_len, unsigned int iv_len,
489			bool is_encrypt)
490{
491	u32 buflen = 0;
492	u32 pad;
493
494	if (assoc_len)
495		buflen = assoc_len;
496
497	if (cipher_mode == CIPHER_MODE_GCM) {
498		/* AAD needs to be padded in responses too */
499		pad = spum_gcm_ccm_pad_len(cipher_mode, buflen);
500		buflen += pad;
501	}
502	if (cipher_mode == CIPHER_MODE_CCM) {
503		/*
504		 * AAD needs to be padded in responses too
505		 * for CCM, len + 2 needs to be 128-bit aligned.
506		 */
507		pad = spum_gcm_ccm_pad_len(cipher_mode, buflen + 2);
508		buflen += pad;
509	}
510
511	return buflen;
512}
513
514/**
515 * spu_aead_ivlen() - Calculate the length of the AEAD IV to be included
516 * in a SPU request after the AAD and before the payload.
517 * @cipher_mode:  cipher mode
518 * @iv_ctr_len:   initialization vector length in bytes
519 *
520 * In Linux ~4.2 and later, the assoc_data sg includes the IV. So no need
521 * to include the IV as a separate field in the SPU request msg.
522 *
523 * Return: Length of AEAD IV in bytes
524 */
525u8 spum_aead_ivlen(enum spu_cipher_mode cipher_mode, u16 iv_len)
526{
527	return 0;
528}
529
530/**
531 * spum_hash_type() - Determine the type of hash operation.
532 * @src_sent:  The number of bytes in the current request that have already
533 *             been sent to the SPU to be hashed.
534 *
535 * We do not use HASH_TYPE_FULL for requests that fit in a single SPU message.
536 * Using FULL causes failures (such as when the string to be hashed is empty).
537 * For similar reasons, we never use HASH_TYPE_FIN. Instead, submit messages
538 * as INIT or UPDT and do the hash padding in sw.
539 */
540enum hash_type spum_hash_type(u32 src_sent)
541{
542	return src_sent ? HASH_TYPE_UPDT : HASH_TYPE_INIT;
543}
544
545/**
546 * spum_digest_size() - Determine the size of a hash digest to expect the SPU to
547 * return.
548 * alg_digest_size: Number of bytes in the final digest for the given algo
549 * alg:             The hash algorithm
550 * htype:           Type of hash operation (init, update, full, etc)
551 *
552 * When doing incremental hashing for an algorithm with a truncated hash
553 * (e.g., SHA224), the SPU returns the full digest so that it can be fed back as
554 * a partial result for the next chunk.
555 */
556u32 spum_digest_size(u32 alg_digest_size, enum hash_alg alg,
557		     enum hash_type htype)
558{
559	u32 digestsize = alg_digest_size;
560
561	/* SPU returns complete digest when doing incremental hash and truncated
562	 * hash algo.
563	 */
564	if ((htype == HASH_TYPE_INIT) || (htype == HASH_TYPE_UPDT)) {
565		if (alg == HASH_ALG_SHA224)
566			digestsize = SHA256_DIGEST_SIZE;
567		else if (alg == HASH_ALG_SHA384)
568			digestsize = SHA512_DIGEST_SIZE;
569	}
570	return digestsize;
571}
572
573/**
574 * spum_create_request() - Build a SPU request message header, up to and
575 * including the BD header. Construct the message starting at spu_hdr. Caller
576 * should allocate this buffer in DMA-able memory at least SPU_HEADER_ALLOC_LEN
577 * bytes long.
578 * @spu_hdr: Start of buffer where SPU request header is to be written
579 * @req_opts: SPU request message options
580 * @cipher_parms: Parameters related to cipher algorithm
581 * @hash_parms:   Parameters related to hash algorithm
582 * @aead_parms:   Parameters related to AEAD operation
583 * @data_size:    Length of data to be encrypted or authenticated. If AEAD, does
584 *		  not include length of AAD.
585
586 * Return: the length of the SPU header in bytes. 0 if an error occurs.
587 */
588u32 spum_create_request(u8 *spu_hdr,
589			struct spu_request_opts *req_opts,
590			struct spu_cipher_parms *cipher_parms,
591			struct spu_hash_parms *hash_parms,
592			struct spu_aead_parms *aead_parms,
593			unsigned int data_size)
594{
595	struct SPUHEADER *spuh;
596	struct BDESC_HEADER *bdesc;
597	struct BD_HEADER *bd;
598
599	u8 *ptr;
600	u32 protocol_bits = 0;
601	u32 cipher_bits = 0;
602	u32 ecf_bits = 0;
603	u8 sctx_words = 0;
604	unsigned int buf_len = 0;
605
606	/* size of the cipher payload */
607	unsigned int cipher_len = hash_parms->prebuf_len + data_size +
608				hash_parms->pad_len;
609
610	/* offset of prebuf or data from end of BD header */
611	unsigned int cipher_offset = aead_parms->assoc_size +
612		aead_parms->iv_len + aead_parms->aad_pad_len;
613
614	/* total size of the DB data (without STAT word padding) */
615	unsigned int real_db_size = spu_real_db_size(aead_parms->assoc_size,
616						 aead_parms->iv_len,
617						 hash_parms->prebuf_len,
618						 data_size,
619						 aead_parms->aad_pad_len,
620						 aead_parms->data_pad_len,
621						 hash_parms->pad_len);
622
623	unsigned int auth_offset = 0;
624	unsigned int offset_iv = 0;
625
626	/* size/offset of the auth payload */
627	unsigned int auth_len;
628
629	auth_len = real_db_size;
630
631	if (req_opts->is_aead && req_opts->is_inbound)
632		cipher_len -= hash_parms->digestsize;
633
634	if (req_opts->is_aead && req_opts->is_inbound)
635		auth_len -= hash_parms->digestsize;
636
637	if ((hash_parms->alg == HASH_ALG_AES) &&
638	    (hash_parms->mode == HASH_MODE_XCBC)) {
639		auth_len -= hash_parms->pad_len;
640		cipher_len -= hash_parms->pad_len;
641	}
642
643	flow_log("%s()\n", __func__);
644	flow_log("  in:%u authFirst:%u\n",
645		 req_opts->is_inbound, req_opts->auth_first);
646	flow_log("  %s. cipher alg:%u mode:%u type %u\n",
647		 spu_alg_name(cipher_parms->alg, cipher_parms->mode),
648		 cipher_parms->alg, cipher_parms->mode, cipher_parms->type);
649	flow_log("    key: %d\n", cipher_parms->key_len);
650	flow_dump("    key: ", cipher_parms->key_buf, cipher_parms->key_len);
651	flow_log("    iv: %d\n", cipher_parms->iv_len);
652	flow_dump("    iv: ", cipher_parms->iv_buf, cipher_parms->iv_len);
653	flow_log("  auth alg:%u mode:%u type %u\n",
654		 hash_parms->alg, hash_parms->mode, hash_parms->type);
655	flow_log("  digestsize: %u\n", hash_parms->digestsize);
656	flow_log("  authkey: %d\n", hash_parms->key_len);
657	flow_dump("  authkey: ", hash_parms->key_buf, hash_parms->key_len);
658	flow_log("  assoc_size:%u\n", aead_parms->assoc_size);
659	flow_log("  prebuf_len:%u\n", hash_parms->prebuf_len);
660	flow_log("  data_size:%u\n", data_size);
661	flow_log("  hash_pad_len:%u\n", hash_parms->pad_len);
662	flow_log("  real_db_size:%u\n", real_db_size);
663	flow_log(" auth_offset:%u auth_len:%u cipher_offset:%u cipher_len:%u\n",
664		 auth_offset, auth_len, cipher_offset, cipher_len);
665	flow_log("  aead_iv: %u\n", aead_parms->iv_len);
666
667	/* starting out: zero the header (plus some) */
668	ptr = spu_hdr;
669	memset(ptr, 0, sizeof(struct SPUHEADER));
670
671	/* format master header word */
672	/* Do not set the next bit even though the datasheet says to */
673	spuh = (struct SPUHEADER *)ptr;
674	ptr += sizeof(struct SPUHEADER);
675	buf_len += sizeof(struct SPUHEADER);
676
677	spuh->mh.op_code = SPU_CRYPTO_OPERATION_GENERIC;
678	spuh->mh.flags |= (MH_SCTX_PRES | MH_BDESC_PRES | MH_BD_PRES);
679
680	/* Format sctx word 0 (protocol_bits) */
681	sctx_words = 3;		/* size in words */
682
683	/* Format sctx word 1 (cipher_bits) */
684	if (req_opts->is_inbound)
685		cipher_bits |= CIPHER_INBOUND;
686	if (req_opts->auth_first)
687		cipher_bits |= CIPHER_ORDER;
688
689	/* Set the crypto parameters in the cipher.flags */
690	cipher_bits |= cipher_parms->alg << CIPHER_ALG_SHIFT;
691	cipher_bits |= cipher_parms->mode << CIPHER_MODE_SHIFT;
692	cipher_bits |= cipher_parms->type << CIPHER_TYPE_SHIFT;
693
694	/* Set the auth parameters in the cipher.flags */
695	cipher_bits |= hash_parms->alg << HASH_ALG_SHIFT;
696	cipher_bits |= hash_parms->mode << HASH_MODE_SHIFT;
697	cipher_bits |= hash_parms->type << HASH_TYPE_SHIFT;
698
699	/*
700	 * Format sctx extensions if required, and update main fields if
701	 * required)
702	 */
703	if (hash_parms->alg) {
704		/* Write the authentication key material if present */
705		if (hash_parms->key_len) {
706			memcpy(ptr, hash_parms->key_buf, hash_parms->key_len);
707			ptr += hash_parms->key_len;
708			buf_len += hash_parms->key_len;
709			sctx_words += hash_parms->key_len / 4;
710		}
711
712		if ((cipher_parms->mode == CIPHER_MODE_GCM) ||
713		    (cipher_parms->mode == CIPHER_MODE_CCM))
714			/* unpadded length */
715			offset_iv = aead_parms->assoc_size;
716
717		/* if GCM/CCM we need to write ICV into the payload */
718		if (!req_opts->is_inbound) {
719			if ((cipher_parms->mode == CIPHER_MODE_GCM) ||
720			    (cipher_parms->mode == CIPHER_MODE_CCM))
721				ecf_bits |= 1 << INSERT_ICV_SHIFT;
722		} else {
723			ecf_bits |= CHECK_ICV;
724		}
725
726		/* Inform the SPU of the ICV size (in words) */
727		if (hash_parms->digestsize == 64)
728			cipher_bits |= ICV_IS_512;
729		else
730			ecf_bits |=
731			(hash_parms->digestsize / 4) << ICV_SIZE_SHIFT;
732	}
733
734	if (req_opts->bd_suppress)
735		ecf_bits |= BD_SUPPRESS;
736
737	/* copy the encryption keys in the SAD entry */
738	if (cipher_parms->alg) {
739		if (cipher_parms->key_len) {
740			memcpy(ptr, cipher_parms->key_buf,
741			       cipher_parms->key_len);
742			ptr += cipher_parms->key_len;
743			buf_len += cipher_parms->key_len;
744			sctx_words += cipher_parms->key_len / 4;
745		}
746
747		/*
748		 * if encrypting then set IV size, use SCTX IV unless no IV
749		 * given here
750		 */
751		if (cipher_parms->iv_buf && cipher_parms->iv_len) {
752			/* Use SCTX IV */
753			ecf_bits |= SCTX_IV;
754
755			/* cipher iv provided so put it in here */
756			memcpy(ptr, cipher_parms->iv_buf, cipher_parms->iv_len);
757
758			ptr += cipher_parms->iv_len;
759			buf_len += cipher_parms->iv_len;
760			sctx_words += cipher_parms->iv_len / 4;
761		}
762	}
763
764	/*
765	 * RFC4543 (GMAC/ESP) requires data to be sent as part of AAD
766	 * so we need to override the BDESC parameters.
767	 */
768	if (req_opts->is_rfc4543) {
769		if (req_opts->is_inbound)
770			data_size -= hash_parms->digestsize;
771		offset_iv = aead_parms->assoc_size + data_size;
772		cipher_len = 0;
773		cipher_offset = offset_iv;
774		auth_len = cipher_offset + aead_parms->data_pad_len;
775	}
776
777	/* write in the total sctx length now that we know it */
778	protocol_bits |= sctx_words;
779
780	/* Endian adjust the SCTX */
781	spuh->sa.proto_flags = cpu_to_be32(protocol_bits);
782	spuh->sa.cipher_flags = cpu_to_be32(cipher_bits);
783	spuh->sa.ecf = cpu_to_be32(ecf_bits);
784
785	/* === create the BDESC section === */
786	bdesc = (struct BDESC_HEADER *)ptr;
787
788	bdesc->offset_mac = cpu_to_be16(auth_offset);
789	bdesc->length_mac = cpu_to_be16(auth_len);
790	bdesc->offset_crypto = cpu_to_be16(cipher_offset);
791	bdesc->length_crypto = cpu_to_be16(cipher_len);
792
793	/*
794	 * CCM in SPU-M requires that ICV not be in same 32-bit word as data or
795	 * padding.  So account for padding as necessary.
796	 */
797	if (cipher_parms->mode == CIPHER_MODE_CCM)
798		auth_len += spum_wordalign_padlen(auth_len);
799
800	bdesc->offset_icv = cpu_to_be16(auth_len);
801	bdesc->offset_iv = cpu_to_be16(offset_iv);
802
803	ptr += sizeof(struct BDESC_HEADER);
804	buf_len += sizeof(struct BDESC_HEADER);
805
806	/* === no MFM section === */
807
808	/* === create the BD section === */
809
810	/* add the BD header */
811	bd = (struct BD_HEADER *)ptr;
812	bd->size = cpu_to_be16(real_db_size);
813	bd->prev_length = 0;
814
815	ptr += sizeof(struct BD_HEADER);
816	buf_len += sizeof(struct BD_HEADER);
817
818	packet_dump("  SPU request header: ", spu_hdr, buf_len);
819
820	return buf_len;
821}
822
823/**
824 * spum_cipher_req_init() - Build a SPU request message header, up to and
825 * including the BD header.
826 * @spu_hdr:      Start of SPU request header (MH)
827 * @cipher_parms: Parameters that describe the cipher request
828 *
829 * Construct the message starting at spu_hdr. Caller should allocate this buffer
830 * in DMA-able memory at least SPU_HEADER_ALLOC_LEN bytes long.
831 *
832 * Return: the length of the SPU header in bytes. 0 if an error occurs.
833 */
834u16 spum_cipher_req_init(u8 *spu_hdr, struct spu_cipher_parms *cipher_parms)
835{
836	struct SPUHEADER *spuh;
837	u32 protocol_bits = 0;
838	u32 cipher_bits = 0;
839	u32 ecf_bits = 0;
840	u8 sctx_words = 0;
841	u8 *ptr = spu_hdr;
842
843	flow_log("%s()\n", __func__);
844	flow_log("  cipher alg:%u mode:%u type %u\n", cipher_parms->alg,
845		 cipher_parms->mode, cipher_parms->type);
846	flow_log("  cipher_iv_len: %u\n", cipher_parms->iv_len);
847	flow_log("    key: %d\n", cipher_parms->key_len);
848	flow_dump("    key: ", cipher_parms->key_buf, cipher_parms->key_len);
849
850	/* starting out: zero the header (plus some) */
851	memset(spu_hdr, 0, sizeof(struct SPUHEADER));
852	ptr += sizeof(struct SPUHEADER);
853
854	/* format master header word */
855	/* Do not set the next bit even though the datasheet says to */
856	spuh = (struct SPUHEADER *)spu_hdr;
857
858	spuh->mh.op_code = SPU_CRYPTO_OPERATION_GENERIC;
859	spuh->mh.flags |= (MH_SCTX_PRES | MH_BDESC_PRES | MH_BD_PRES);
860
861	/* Format sctx word 0 (protocol_bits) */
862	sctx_words = 3;		/* size in words */
863
864	/* copy the encryption keys in the SAD entry */
865	if (cipher_parms->alg) {
866		if (cipher_parms->key_len) {
867			ptr += cipher_parms->key_len;
868			sctx_words += cipher_parms->key_len / 4;
869		}
870
871		/*
872		 * if encrypting then set IV size, use SCTX IV unless no IV
873		 * given here
874		 */
875		if (cipher_parms->iv_len) {
876			/* Use SCTX IV */
877			ecf_bits |= SCTX_IV;
878			ptr += cipher_parms->iv_len;
879			sctx_words += cipher_parms->iv_len / 4;
880		}
881	}
882
883	/* Set the crypto parameters in the cipher.flags */
884	cipher_bits |= cipher_parms->alg << CIPHER_ALG_SHIFT;
885	cipher_bits |= cipher_parms->mode << CIPHER_MODE_SHIFT;
886	cipher_bits |= cipher_parms->type << CIPHER_TYPE_SHIFT;
887
888	/* copy the encryption keys in the SAD entry */
889	if (cipher_parms->alg && cipher_parms->key_len)
890		memcpy(spuh + 1, cipher_parms->key_buf, cipher_parms->key_len);
891
892	/* write in the total sctx length now that we know it */
893	protocol_bits |= sctx_words;
894
895	/* Endian adjust the SCTX */
896	spuh->sa.proto_flags = cpu_to_be32(protocol_bits);
897
898	/* Endian adjust the SCTX */
899	spuh->sa.cipher_flags = cpu_to_be32(cipher_bits);
900	spuh->sa.ecf = cpu_to_be32(ecf_bits);
901
902	packet_dump("  SPU request header: ", spu_hdr,
903		    sizeof(struct SPUHEADER));
904
905	return sizeof(struct SPUHEADER) + cipher_parms->key_len +
906		cipher_parms->iv_len + sizeof(struct BDESC_HEADER) +
907		sizeof(struct BD_HEADER);
908}
909
910/**
911 * spum_cipher_req_finish() - Finish building a SPU request message header for a
912 * block cipher request. Assumes much of the header was already filled in at
913 * setkey() time in spu_cipher_req_init().
914 * @spu_hdr:         Start of the request message header (MH field)
915 * @spu_req_hdr_len: Length in bytes of the SPU request header
916 * @isInbound:       0 encrypt, 1 decrypt
917 * @cipher_parms:    Parameters describing cipher operation to be performed
918 * @data_size:       Length of the data in the BD field
919 *
920 * Assumes much of the header was already filled in at setkey() time in
921 * spum_cipher_req_init().
922 * spum_cipher_req_init() fills in the encryption key.
923 */
924void spum_cipher_req_finish(u8 *spu_hdr,
925			    u16 spu_req_hdr_len,
926			    unsigned int is_inbound,
927			    struct spu_cipher_parms *cipher_parms,
928			    unsigned int data_size)
929{
930	struct SPUHEADER *spuh;
931	struct BDESC_HEADER *bdesc;
932	struct BD_HEADER *bd;
933	u8 *bdesc_ptr = spu_hdr + spu_req_hdr_len -
934	    (sizeof(struct BD_HEADER) + sizeof(struct BDESC_HEADER));
935
936	u32 cipher_bits;
937
938	flow_log("%s()\n", __func__);
939	flow_log(" in: %u\n", is_inbound);
940	flow_log(" cipher alg: %u, cipher_type: %u\n", cipher_parms->alg,
941		 cipher_parms->type);
942
943	/*
944	 * In XTS mode, API puts "i" parameter (block tweak) in IV.  For
945	 * SPU-M, should be in start of the BD; tx_sg_create() copies it there.
946	 * IV in SPU msg for SPU-M should be 0, since that's the "j" parameter
947	 * (block ctr within larger data unit) - given we can send entire disk
948	 * block (<= 4KB) in 1 SPU msg, don't need to use this parameter.
949	 */
950	if (cipher_parms->mode == CIPHER_MODE_XTS)
951		memset(cipher_parms->iv_buf, 0, cipher_parms->iv_len);
952
953	flow_log(" iv len: %d\n", cipher_parms->iv_len);
954	flow_dump("    iv: ", cipher_parms->iv_buf, cipher_parms->iv_len);
955	flow_log(" data_size: %u\n", data_size);
956
957	/* format master header word */
958	/* Do not set the next bit even though the datasheet says to */
959	spuh = (struct SPUHEADER *)spu_hdr;
960
961	/* cipher_bits was initialized at setkey time */
962	cipher_bits = be32_to_cpu(spuh->sa.cipher_flags);
963
964	/* Format sctx word 1 (cipher_bits) */
965	if (is_inbound)
966		cipher_bits |= CIPHER_INBOUND;
967	else
968		cipher_bits &= ~CIPHER_INBOUND;
969
970	if (cipher_parms->alg && cipher_parms->iv_buf && cipher_parms->iv_len)
971		/* cipher iv provided so put it in here */
972		memcpy(bdesc_ptr - cipher_parms->iv_len, cipher_parms->iv_buf,
973		       cipher_parms->iv_len);
974
975	spuh->sa.cipher_flags = cpu_to_be32(cipher_bits);
976
977	/* === create the BDESC section === */
978	bdesc = (struct BDESC_HEADER *)bdesc_ptr;
979	bdesc->offset_mac = 0;
980	bdesc->length_mac = 0;
981	bdesc->offset_crypto = 0;
982
983	/* XTS mode, data_size needs to include tweak parameter */
984	if (cipher_parms->mode == CIPHER_MODE_XTS)
985		bdesc->length_crypto = cpu_to_be16(data_size +
986						  SPU_XTS_TWEAK_SIZE);
987	else
988		bdesc->length_crypto = cpu_to_be16(data_size);
989
990	bdesc->offset_icv = 0;
991	bdesc->offset_iv = 0;
992
993	/* === no MFM section === */
994
995	/* === create the BD section === */
996	/* add the BD header */
997	bd = (struct BD_HEADER *)(bdesc_ptr + sizeof(struct BDESC_HEADER));
998	bd->size = cpu_to_be16(data_size);
999
1000	/* XTS mode, data_size needs to include tweak parameter */
1001	if (cipher_parms->mode == CIPHER_MODE_XTS)
1002		bd->size = cpu_to_be16(data_size + SPU_XTS_TWEAK_SIZE);
1003	else
1004		bd->size = cpu_to_be16(data_size);
1005
1006	bd->prev_length = 0;
1007
1008	packet_dump("  SPU request header: ", spu_hdr, spu_req_hdr_len);
1009}
1010
1011/**
1012 * spum_request_pad() - Create pad bytes at the end of the data.
1013 * @pad_start:		Start of buffer where pad bytes are to be written
1014 * @gcm_ccm_padding:	length of GCM/CCM padding, in bytes
1015 * @hash_pad_len:	Number of bytes of padding extend data to full block
1016 * @auth_alg:		authentication algorithm
1017 * @auth_mode:		authentication mode
1018 * @total_sent:		length inserted at end of hash pad
1019 * @status_padding:	Number of bytes of padding to align STATUS word
1020 *
1021 * There may be three forms of pad:
1022 *  1. GCM/CCM pad - for GCM/CCM mode ciphers, pad to 16-byte alignment
1023 *  2. hash pad - pad to a block length, with 0x80 data terminator and
1024 *                size at the end
1025 *  3. STAT pad - to ensure the STAT field is 4-byte aligned
1026 */
1027void spum_request_pad(u8 *pad_start,
1028		      u32 gcm_ccm_padding,
1029		      u32 hash_pad_len,
1030		      enum hash_alg auth_alg,
1031		      enum hash_mode auth_mode,
1032		      unsigned int total_sent, u32 status_padding)
1033{
1034	u8 *ptr = pad_start;
1035
1036	/* fix data alignent for GCM/CCM */
1037	if (gcm_ccm_padding > 0) {
1038		flow_log("  GCM: padding to 16 byte alignment: %u bytes\n",
1039			 gcm_ccm_padding);
1040		memset(ptr, 0, gcm_ccm_padding);
1041		ptr += gcm_ccm_padding;
1042	}
1043
1044	if (hash_pad_len > 0) {
1045		/* clear the padding section */
1046		memset(ptr, 0, hash_pad_len);
1047
1048		if ((auth_alg == HASH_ALG_AES) &&
1049		    (auth_mode == HASH_MODE_XCBC)) {
1050			/* AES/XCBC just requires padding to be 0s */
1051			ptr += hash_pad_len;
1052		} else {
1053			/* terminate the data */
1054			*ptr = 0x80;
1055			ptr += (hash_pad_len - sizeof(u64));
1056
1057			/* add the size at the end as required per alg */
1058			if (auth_alg == HASH_ALG_MD5)
1059				*(u64 *)ptr = cpu_to_le64((u64)total_sent * 8);
1060			else		/* SHA1, SHA2-224, SHA2-256 */
1061				*(u64 *)ptr = cpu_to_be64((u64)total_sent * 8);
1062			ptr += sizeof(u64);
1063		}
1064	}
1065
1066	/* pad to a 4byte alignment for STAT */
1067	if (status_padding > 0) {
1068		flow_log("  STAT: padding to 4 byte alignment: %u bytes\n",
1069			 status_padding);
1070
1071		memset(ptr, 0, status_padding);
1072		ptr += status_padding;
1073	}
1074}
1075
1076/**
1077 * spum_xts_tweak_in_payload() - Indicate that SPUM DOES place the XTS tweak
1078 * field in the packet payload (rather than using IV)
1079 *
1080 * Return: 1
1081 */
1082u8 spum_xts_tweak_in_payload(void)
1083{
1084	return 1;
1085}
1086
1087/**
1088 * spum_tx_status_len() - Return the length of the STATUS field in a SPU
1089 * response message.
1090 *
1091 * Return: Length of STATUS field in bytes.
1092 */
1093u8 spum_tx_status_len(void)
1094{
1095	return SPU_TX_STATUS_LEN;
1096}
1097
1098/**
1099 * spum_rx_status_len() - Return the length of the STATUS field in a SPU
1100 * response message.
1101 *
1102 * Return: Length of STATUS field in bytes.
1103 */
1104u8 spum_rx_status_len(void)
1105{
1106	return SPU_RX_STATUS_LEN;
1107}
1108
1109/**
1110 * spum_status_process() - Process the status from a SPU response message.
1111 * @statp:  start of STATUS word
1112 * Return:
1113 *   0 - if status is good and response should be processed
1114 *   !0 - status indicates an error and response is invalid
1115 */
1116int spum_status_process(u8 *statp)
1117{
1118	u32 status;
1119
1120	status = __be32_to_cpu(*(__be32 *)statp);
1121	flow_log("SPU response STATUS %#08x\n", status);
1122	if (status & SPU_STATUS_ERROR_FLAG) {
1123		pr_err("%s() Warning: Error result from SPU: %#08x\n",
1124		       __func__, status);
1125		if (status & SPU_STATUS_INVALID_ICV)
1126			return SPU_INVALID_ICV;
1127		return -EBADMSG;
1128	}
1129	return 0;
1130}
1131
1132/**
1133 * spum_ccm_update_iv() - Update the IV as per the requirements for CCM mode.
1134 *
1135 * @digestsize:		Digest size of this request
1136 * @cipher_parms:	(pointer to) cipher parmaeters, includes IV buf & IV len
1137 * @assoclen:		Length of AAD data
1138 * @chunksize:		length of input data to be sent in this req
1139 * @is_encrypt:		true if this is an output/encrypt operation
1140 * @is_esp:		true if this is an ESP / RFC4309 operation
1141 *
1142 */
1143void spum_ccm_update_iv(unsigned int digestsize,
1144			struct spu_cipher_parms *cipher_parms,
1145			unsigned int assoclen,
1146			unsigned int chunksize,
1147			bool is_encrypt,
1148			bool is_esp)
1149{
1150	u8 L;		/* L from CCM algorithm, length of plaintext data */
1151	u8 mprime;	/* M' from CCM algo, (M - 2) / 2, where M=authsize */
1152	u8 adata;
1153
1154	if (cipher_parms->iv_len != CCM_AES_IV_SIZE) {
1155		pr_err("%s(): Invalid IV len %d for CCM mode, should be %d\n",
1156		       __func__, cipher_parms->iv_len, CCM_AES_IV_SIZE);
1157		return;
1158	}
1159
1160	/*
1161	 * IV needs to be formatted as follows:
1162	 *
1163	 * |          Byte 0               | Bytes 1 - N | Bytes (N+1) - 15 |
1164	 * | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Bits 7 - 0  |    Bits 7 - 0    |
1165	 * | 0 |Ad?|(M - 2) / 2|   L - 1   |    Nonce    | Plaintext Length |
1166	 *
1167	 * Ad? = 1 if AAD present, 0 if not present
1168	 * M = size of auth field, 8, 12, or 16 bytes (SPU-M) -or-
1169	 *                         4, 6, 8, 10, 12, 14, 16 bytes (SPU2)
1170	 * L = Size of Plaintext Length field; Nonce size = 15 - L
1171	 *
1172	 * It appears that the crypto API already expects the L-1 portion
1173	 * to be set in the first byte of the IV, which implicitly determines
1174	 * the nonce size, and also fills in the nonce.  But the other bits
1175	 * in byte 0 as well as the plaintext length need to be filled in.
1176	 *
1177	 * In rfc4309/esp mode, L is not already in the supplied IV and
1178	 * we need to fill it in, as well as move the IV data to be after
1179	 * the salt
1180	 */
1181	if (is_esp) {
1182		L = CCM_ESP_L_VALUE;	/* RFC4309 has fixed L */
1183	} else {
1184		/* L' = plaintext length - 1 so Plaintext length is L' + 1 */
1185		L = ((cipher_parms->iv_buf[0] & CCM_B0_L_PRIME) >>
1186		      CCM_B0_L_PRIME_SHIFT) + 1;
1187	}
1188
1189	mprime = (digestsize - 2) >> 1;  /* M' = (M - 2) / 2 */
1190	adata = (assoclen > 0);  /* adata = 1 if any associated data */
1191
1192	cipher_parms->iv_buf[0] = (adata << CCM_B0_ADATA_SHIFT) |
1193				  (mprime << CCM_B0_M_PRIME_SHIFT) |
1194				  ((L - 1) << CCM_B0_L_PRIME_SHIFT);
1195
1196	/* Nonce is already filled in by crypto API, and is 15 - L bytes */
1197
1198	/* Don't include digest in plaintext size when decrypting */
1199	if (!is_encrypt)
1200		chunksize -= digestsize;
1201
1202	/* Fill in length of plaintext, formatted to be L bytes long */
1203	format_value_ccm(chunksize, &cipher_parms->iv_buf[15 - L + 1], L);
1204}
1205
1206/**
1207 * spum_wordalign_padlen() - Given the length of a data field, determine the
1208 * padding required to align the data following this field on a 4-byte boundary.
1209 * @data_size: length of data field in bytes
1210 *
1211 * Return: length of status field padding, in bytes
1212 */
1213u32 spum_wordalign_padlen(u32 data_size)
1214{
1215	return ((data_size + 3) & ~3) - data_size;
1216}
1217