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Commit 643b39b0 authored by Yuan Kang's avatar Yuan Kang Committed by Herbert Xu
Browse files

crypto: caam - chaining support



support chained scatterlists for aead, ablkcipher and ahash.

Signed-off-by: default avatarYuan Kang <Yuan.Kang@freescale.com>

- fix dma unmap leak
- un-unlikely src == dst, due to experience with AF_ALG

Signed-off-by: default avatarKudupudi Ugendreshwar <B38865@freescale.com>
Signed-off-by: default avatarKim Phillips <kim.phillips@freescale.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent b0e09bae
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+70 −44
Original line number Diff line number Diff line
@@ -654,8 +654,11 @@ static int ablkcipher_setkey(struct crypto_ablkcipher *ablkcipher,
/*
 * aead_edesc - s/w-extended aead descriptor
 * @assoc_nents: number of segments in associated data (SPI+Seq) scatterlist
 * @assoc_chained: if source is chained
 * @src_nents: number of segments in input scatterlist
 * @src_chained: if source is chained
 * @dst_nents: number of segments in output scatterlist
 * @dst_chained: if destination is chained
 * @iv_dma: dma address of iv for checking continuity and link table
 * @desc: h/w descriptor (variable length; must not exceed MAX_CAAM_DESCSIZE)
 * @sec4_sg_bytes: length of dma mapped sec4_sg space
@@ -664,8 +667,11 @@ static int ablkcipher_setkey(struct crypto_ablkcipher *ablkcipher,
 */
struct aead_edesc {
	int assoc_nents;
	bool assoc_chained;
	int src_nents;
	bool src_chained;
	int dst_nents;
	bool dst_chained;
	dma_addr_t iv_dma;
	int sec4_sg_bytes;
	dma_addr_t sec4_sg_dma;
@@ -676,7 +682,9 @@ struct aead_edesc {
/*
 * ablkcipher_edesc - s/w-extended ablkcipher descriptor
 * @src_nents: number of segments in input scatterlist
 * @src_chained: if source is chained
 * @dst_nents: number of segments in output scatterlist
 * @dst_chained: if destination is chained
 * @iv_dma: dma address of iv for checking continuity and link table
 * @desc: h/w descriptor (variable length; must not exceed MAX_CAAM_DESCSIZE)
 * @sec4_sg_bytes: length of dma mapped sec4_sg space
@@ -685,7 +693,9 @@ struct aead_edesc {
 */
struct ablkcipher_edesc {
	int src_nents;
	bool src_chained;
	int dst_nents;
	bool dst_chained;
	dma_addr_t iv_dma;
	int sec4_sg_bytes;
	dma_addr_t sec4_sg_dma;
@@ -694,15 +704,19 @@ struct ablkcipher_edesc {
};

static void caam_unmap(struct device *dev, struct scatterlist *src,
		       struct scatterlist *dst, int src_nents, int dst_nents,
		       struct scatterlist *dst, int src_nents,
		       bool src_chained, int dst_nents, bool dst_chained,
		       dma_addr_t iv_dma, int ivsize, dma_addr_t sec4_sg_dma,
		       int sec4_sg_bytes)
{
	if (unlikely(dst != src)) {
		dma_unmap_sg(dev, src, src_nents, DMA_TO_DEVICE);
		dma_unmap_sg(dev, dst, dst_nents, DMA_FROM_DEVICE);
	if (dst != src) {
		dma_unmap_sg_chained(dev, src, src_nents ? : 1, DMA_TO_DEVICE,
				     src_chained);
		dma_unmap_sg_chained(dev, dst, dst_nents ? : 1, DMA_FROM_DEVICE,
				     dst_chained);
	} else {
		dma_unmap_sg(dev, src, src_nents, DMA_BIDIRECTIONAL);
		dma_unmap_sg_chained(dev, src, src_nents ? : 1,
				     DMA_BIDIRECTIONAL, src_chained);
	}

	if (iv_dma)
@@ -719,12 +733,13 @@ static void aead_unmap(struct device *dev,
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	int ivsize = crypto_aead_ivsize(aead);

	dma_unmap_sg(dev, req->assoc, edesc->assoc_nents, DMA_TO_DEVICE);
	dma_unmap_sg_chained(dev, req->assoc, edesc->assoc_nents,
			     DMA_TO_DEVICE, edesc->assoc_chained);

	caam_unmap(dev, req->src, req->dst,
		   edesc->src_nents, edesc->dst_nents,
		   edesc->iv_dma, ivsize, edesc->sec4_sg_dma,
		   edesc->sec4_sg_bytes);
		   edesc->src_nents, edesc->src_chained, edesc->dst_nents,
		   edesc->dst_chained, edesc->iv_dma, ivsize,
		   edesc->sec4_sg_dma, edesc->sec4_sg_bytes);
}

static void ablkcipher_unmap(struct device *dev,
@@ -735,9 +750,9 @@ static void ablkcipher_unmap(struct device *dev,
	int ivsize = crypto_ablkcipher_ivsize(ablkcipher);

	caam_unmap(dev, req->src, req->dst,
		   edesc->src_nents, edesc->dst_nents,
		   edesc->iv_dma, ivsize, edesc->sec4_sg_dma,
		   edesc->sec4_sg_bytes);
		   edesc->src_nents, edesc->src_chained, edesc->dst_nents,
		   edesc->dst_chained, edesc->iv_dma, ivsize,
		   edesc->sec4_sg_dma, edesc->sec4_sg_bytes);
}

static void aead_encrypt_done(struct device *jrdev, u32 *desc, u32 err,
@@ -1128,25 +1143,26 @@ static struct aead_edesc *aead_edesc_alloc(struct aead_request *req,
	dma_addr_t iv_dma = 0;
	int sgc;
	bool all_contig = true;
	bool assoc_chained = false, src_chained = false, dst_chained = false;
	int ivsize = crypto_aead_ivsize(aead);
	int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes;

	assoc_nents = sg_count(req->assoc, req->assoclen);
	src_nents = sg_count(req->src, req->cryptlen);
	assoc_nents = sg_count(req->assoc, req->assoclen, &assoc_chained);
	src_nents = sg_count(req->src, req->cryptlen, &src_chained);

	if (unlikely(req->dst != req->src))
		dst_nents = sg_count(req->dst, req->cryptlen);
		dst_nents = sg_count(req->dst, req->cryptlen, &dst_chained);

	sgc = dma_map_sg(jrdev, req->assoc, assoc_nents ? : 1,
			 DMA_BIDIRECTIONAL);
	sgc = dma_map_sg_chained(jrdev, req->assoc, assoc_nents ? : 1,
				 DMA_BIDIRECTIONAL, assoc_chained);
	if (likely(req->src == req->dst)) {
		sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
				 DMA_BIDIRECTIONAL);
		sgc = dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
					 DMA_BIDIRECTIONAL, src_chained);
	} else {
		sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
				 DMA_TO_DEVICE);
		sgc = dma_map_sg(jrdev, req->dst, dst_nents ? : 1,
				 DMA_FROM_DEVICE);
		sgc = dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
					 DMA_TO_DEVICE, src_chained);
		sgc = dma_map_sg_chained(jrdev, req->dst, dst_nents ? : 1,
					 DMA_FROM_DEVICE, dst_chained);
	}

	/* Check if data are contiguous */
@@ -1172,8 +1188,11 @@ static struct aead_edesc *aead_edesc_alloc(struct aead_request *req,
	}

	edesc->assoc_nents = assoc_nents;
	edesc->assoc_chained = assoc_chained;
	edesc->src_nents = src_nents;
	edesc->src_chained = src_chained;
	edesc->dst_nents = dst_nents;
	edesc->dst_chained = dst_chained;
	edesc->iv_dma = iv_dma;
	edesc->sec4_sg_bytes = sec4_sg_bytes;
	edesc->sec4_sg = (void *)edesc + sizeof(struct aead_edesc) +
@@ -1307,24 +1326,25 @@ static struct aead_edesc *aead_giv_edesc_alloc(struct aead_givcrypt_request
	int sgc;
	u32 contig = GIV_SRC_CONTIG | GIV_DST_CONTIG;
	int ivsize = crypto_aead_ivsize(aead);
	bool assoc_chained = false, src_chained = false, dst_chained = false;
	int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes;

	assoc_nents = sg_count(req->assoc, req->assoclen);
	src_nents = sg_count(req->src, req->cryptlen);
	assoc_nents = sg_count(req->assoc, req->assoclen, &assoc_chained);
	src_nents = sg_count(req->src, req->cryptlen, &src_chained);

	if (unlikely(req->dst != req->src))
		dst_nents = sg_count(req->dst, req->cryptlen);
		dst_nents = sg_count(req->dst, req->cryptlen, &dst_chained);

	sgc = dma_map_sg(jrdev, req->assoc, assoc_nents ? : 1,
			 DMA_BIDIRECTIONAL);
	sgc = dma_map_sg_chained(jrdev, req->assoc, assoc_nents ? : 1,
				 DMA_BIDIRECTIONAL, assoc_chained);
	if (likely(req->src == req->dst)) {
		sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
				 DMA_BIDIRECTIONAL);
		sgc = dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
					 DMA_BIDIRECTIONAL, src_chained);
	} else {
		sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
				 DMA_TO_DEVICE);
		sgc = dma_map_sg(jrdev, req->dst, dst_nents ? : 1,
				 DMA_FROM_DEVICE);
		sgc = dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
					 DMA_TO_DEVICE, src_chained);
		sgc = dma_map_sg_chained(jrdev, req->dst, dst_nents ? : 1,
					 DMA_FROM_DEVICE, dst_chained);
	}

	/* Check if data are contiguous */
@@ -1358,8 +1378,11 @@ static struct aead_edesc *aead_giv_edesc_alloc(struct aead_givcrypt_request
	}

	edesc->assoc_nents = assoc_nents;
	edesc->assoc_chained = assoc_chained;
	edesc->src_nents = src_nents;
	edesc->src_chained = src_chained;
	edesc->dst_nents = dst_nents;
	edesc->dst_chained = dst_chained;
	edesc->iv_dma = iv_dma;
	edesc->sec4_sg_bytes = sec4_sg_bytes;
	edesc->sec4_sg = (void *)edesc + sizeof(struct aead_edesc) +
@@ -1459,21 +1482,22 @@ static struct ablkcipher_edesc *ablkcipher_edesc_alloc(struct ablkcipher_request
	bool iv_contig = false;
	int sgc;
	int ivsize = crypto_ablkcipher_ivsize(ablkcipher);
	bool src_chained = false, dst_chained = false;
	int sec4_sg_index;

	src_nents = sg_count(req->src, req->nbytes);
	src_nents = sg_count(req->src, req->nbytes, &src_chained);

	if (unlikely(req->dst != req->src))
		dst_nents = sg_count(req->dst, req->nbytes);
	if (req->dst != req->src)
		dst_nents = sg_count(req->dst, req->nbytes, &dst_chained);

	if (likely(req->src == req->dst)) {
		sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
				 DMA_BIDIRECTIONAL);
		sgc = dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
					 DMA_BIDIRECTIONAL, src_chained);
	} else {
		sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
				 DMA_TO_DEVICE);
		sgc = dma_map_sg(jrdev, req->dst, dst_nents ? : 1,
				 DMA_FROM_DEVICE);
		sgc = dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
					 DMA_TO_DEVICE, src_chained);
		sgc = dma_map_sg_chained(jrdev, req->dst, dst_nents ? : 1,
					 DMA_FROM_DEVICE, dst_chained);
	}

	/*
@@ -1497,7 +1521,9 @@ static struct ablkcipher_edesc *ablkcipher_edesc_alloc(struct ablkcipher_request
	}

	edesc->src_nents = src_nents;
	edesc->src_chained = src_chained;
	edesc->dst_nents = dst_nents;
	edesc->dst_chained = dst_chained;
	edesc->sec4_sg_bytes = sec4_sg_bytes;
	edesc->sec4_sg = (void *)edesc + sizeof(struct ablkcipher_edesc) +
			 desc_bytes;
@@ -1510,7 +1536,7 @@ static struct ablkcipher_edesc *ablkcipher_edesc_alloc(struct ablkcipher_request
		sec4_sg_index += 1 + src_nents;
	}

	if (unlikely(dst_nents)) {
	if (dst_nents) {
		sg_to_sec4_sg_last(req->dst, dst_nents,
			edesc->sec4_sg + sec4_sg_index, 0);
	}
+38 −15
Original line number Diff line number Diff line
@@ -175,9 +175,10 @@ static inline dma_addr_t buf_map_to_sec4_sg(struct device *jrdev,
/* Map req->src and put it in link table */
static inline void src_map_to_sec4_sg(struct device *jrdev,
				      struct scatterlist *src, int src_nents,
				      struct sec4_sg_entry *sec4_sg)
				      struct sec4_sg_entry *sec4_sg,
				      bool chained)
{
	dma_map_sg(jrdev, src, src_nents, DMA_TO_DEVICE);
	dma_map_sg_chained(jrdev, src, src_nents, DMA_TO_DEVICE, chained);
	sg_to_sec4_sg_last(src, src_nents, sec4_sg, 0);
}

@@ -563,6 +564,7 @@ static int ahash_setkey(struct crypto_ahash *ahash,
 * ahash_edesc - s/w-extended ahash descriptor
 * @dst_dma: physical mapped address of req->result
 * @sec4_sg_dma: physical mapped address of h/w link table
 * @chained: if source is chained
 * @src_nents: number of segments in input scatterlist
 * @sec4_sg_bytes: length of dma mapped sec4_sg space
 * @sec4_sg: pointer to h/w link table
@@ -571,6 +573,7 @@ static int ahash_setkey(struct crypto_ahash *ahash,
struct ahash_edesc {
	dma_addr_t dst_dma;
	dma_addr_t sec4_sg_dma;
	bool chained;
	int src_nents;
	int sec4_sg_bytes;
	struct sec4_sg_entry *sec4_sg;
@@ -582,7 +585,8 @@ static inline void ahash_unmap(struct device *dev,
			struct ahash_request *req, int dst_len)
{
	if (edesc->src_nents)
		dma_unmap_sg(dev, req->src, edesc->src_nents, DMA_TO_DEVICE);
		dma_unmap_sg_chained(dev, req->src, edesc->src_nents,
				     DMA_TO_DEVICE, edesc->chained);
	if (edesc->dst_dma)
		dma_unmap_single(dev, edesc->dst_dma, dst_len, DMA_FROM_DEVICE);

@@ -775,6 +779,7 @@ static int ahash_update_ctx(struct ahash_request *req)
	dma_addr_t ptr = ctx->sh_desc_update_dma;
	int src_nents, sec4_sg_bytes, sec4_sg_src_index;
	struct ahash_edesc *edesc;
	bool chained = false;
	int ret = 0;
	int sh_len;

@@ -783,7 +788,8 @@ static int ahash_update_ctx(struct ahash_request *req)
	to_hash = in_len - *next_buflen;

	if (to_hash) {
		src_nents = __sg_count(req->src, req->nbytes - (*next_buflen));
		src_nents = __sg_count(req->src, req->nbytes - (*next_buflen),
				       &chained);
		sec4_sg_src_index = 1 + (*buflen ? 1 : 0);
		sec4_sg_bytes = (sec4_sg_src_index + src_nents) *
				 sizeof(struct sec4_sg_entry);
@@ -801,6 +807,7 @@ static int ahash_update_ctx(struct ahash_request *req)
		}

		edesc->src_nents = src_nents;
		edesc->chained = chained;
		edesc->sec4_sg_bytes = sec4_sg_bytes;
		edesc->sec4_sg = (void *)edesc + sizeof(struct ahash_edesc) +
				 DESC_JOB_IO_LEN;
@@ -818,7 +825,8 @@ static int ahash_update_ctx(struct ahash_request *req)

		if (src_nents) {
			src_map_to_sec4_sg(jrdev, req->src, src_nents,
					   edesc->sec4_sg + sec4_sg_src_index);
					   edesc->sec4_sg + sec4_sg_src_index,
					   chained);
			if (*next_buflen) {
				sg_copy_part(next_buf, req->src, to_hash -
					     *buflen, req->nbytes);
@@ -958,10 +966,11 @@ static int ahash_finup_ctx(struct ahash_request *req)
	int src_nents;
	int digestsize = crypto_ahash_digestsize(ahash);
	struct ahash_edesc *edesc;
	bool chained = false;
	int ret = 0;
	int sh_len;

	src_nents = __sg_count(req->src, req->nbytes);
	src_nents = __sg_count(req->src, req->nbytes, &chained);
	sec4_sg_src_index = 1 + (buflen ? 1 : 0);
	sec4_sg_bytes = (sec4_sg_src_index + src_nents) *
			 sizeof(struct sec4_sg_entry);
@@ -979,6 +988,7 @@ static int ahash_finup_ctx(struct ahash_request *req)
	init_job_desc_shared(desc, ptr, sh_len, HDR_SHARE_DEFER | HDR_REVERSE);

	edesc->src_nents = src_nents;
	edesc->chained = chained;
	edesc->sec4_sg_bytes = sec4_sg_bytes;
	edesc->sec4_sg = (void *)edesc + sizeof(struct ahash_edesc) +
			 DESC_JOB_IO_LEN;
@@ -993,7 +1003,7 @@ static int ahash_finup_ctx(struct ahash_request *req)
						last_buflen);

	src_map_to_sec4_sg(jrdev, req->src, src_nents, edesc->sec4_sg +
			   sec4_sg_src_index);
			   sec4_sg_src_index, chained);

	append_seq_in_ptr(desc, edesc->sec4_sg_dma, ctx->ctx_len +
			       buflen + req->nbytes, LDST_SGF);
@@ -1030,12 +1040,14 @@ static int ahash_digest(struct ahash_request *req)
	int src_nents, sec4_sg_bytes;
	dma_addr_t src_dma;
	struct ahash_edesc *edesc;
	bool chained = false;
	int ret = 0;
	u32 options;
	int sh_len;

	src_nents = sg_count(req->src, req->nbytes);
	dma_map_sg(jrdev, req->src, src_nents ? : 1, DMA_TO_DEVICE);
	src_nents = sg_count(req->src, req->nbytes, &chained);
	dma_map_sg_chained(jrdev, req->src, src_nents ? : 1, DMA_TO_DEVICE,
			   chained);
	sec4_sg_bytes = src_nents * sizeof(struct sec4_sg_entry);

	/* allocate space for base edesc and hw desc commands, link tables */
@@ -1050,6 +1062,7 @@ static int ahash_digest(struct ahash_request *req)
	edesc->sec4_sg_dma = dma_map_single(jrdev, edesc->sec4_sg,
					    sec4_sg_bytes, DMA_TO_DEVICE);
	edesc->src_nents = src_nents;
	edesc->chained = chained;

	sh_len = desc_len(sh_desc);
	desc = edesc->hw_desc;
@@ -1157,6 +1170,7 @@ static int ahash_update_no_ctx(struct ahash_request *req)
	struct ahash_edesc *edesc;
	u32 *desc, *sh_desc = ctx->sh_desc_update_first;
	dma_addr_t ptr = ctx->sh_desc_update_first_dma;
	bool chained = false;
	int ret = 0;
	int sh_len;

@@ -1164,7 +1178,8 @@ static int ahash_update_no_ctx(struct ahash_request *req)
	to_hash = in_len - *next_buflen;

	if (to_hash) {
		src_nents = __sg_count(req->src, req->nbytes - (*next_buflen));
		src_nents = __sg_count(req->src, req->nbytes - (*next_buflen),
				       &chained);
		sec4_sg_bytes = (1 + src_nents) *
				sizeof(struct sec4_sg_entry);

@@ -1181,6 +1196,7 @@ static int ahash_update_no_ctx(struct ahash_request *req)
		}

		edesc->src_nents = src_nents;
		edesc->chained = chained;
		edesc->sec4_sg_bytes = sec4_sg_bytes;
		edesc->sec4_sg = (void *)edesc + sizeof(struct ahash_edesc) +
				 DESC_JOB_IO_LEN;
@@ -1191,7 +1207,7 @@ static int ahash_update_no_ctx(struct ahash_request *req)
		state->buf_dma = buf_map_to_sec4_sg(jrdev, edesc->sec4_sg,
						    buf, *buflen);
		src_map_to_sec4_sg(jrdev, req->src, src_nents,
				   edesc->sec4_sg + 1);
				   edesc->sec4_sg + 1, chained);
		if (*next_buflen) {
			sg_copy_part(next_buf, req->src, to_hash - *buflen,
				    req->nbytes);
@@ -1258,10 +1274,11 @@ static int ahash_finup_no_ctx(struct ahash_request *req)
	int sec4_sg_bytes, sec4_sg_src_index, src_nents;
	int digestsize = crypto_ahash_digestsize(ahash);
	struct ahash_edesc *edesc;
	bool chained = false;
	int sh_len;
	int ret = 0;

	src_nents = __sg_count(req->src, req->nbytes);
	src_nents = __sg_count(req->src, req->nbytes, &chained);
	sec4_sg_src_index = 2;
	sec4_sg_bytes = (sec4_sg_src_index + src_nents) *
			 sizeof(struct sec4_sg_entry);
@@ -1279,6 +1296,7 @@ static int ahash_finup_no_ctx(struct ahash_request *req)
	init_job_desc_shared(desc, ptr, sh_len, HDR_SHARE_DEFER | HDR_REVERSE);

	edesc->src_nents = src_nents;
	edesc->chained = chained;
	edesc->sec4_sg_bytes = sec4_sg_bytes;
	edesc->sec4_sg = (void *)edesc + sizeof(struct ahash_edesc) +
			 DESC_JOB_IO_LEN;
@@ -1289,7 +1307,8 @@ static int ahash_finup_no_ctx(struct ahash_request *req)
						state->buf_dma, buflen,
						last_buflen);

	src_map_to_sec4_sg(jrdev, req->src, src_nents, edesc->sec4_sg + 1);
	src_map_to_sec4_sg(jrdev, req->src, src_nents, edesc->sec4_sg + 1,
			   chained);

	append_seq_in_ptr(desc, edesc->sec4_sg_dma, buflen +
			       req->nbytes, LDST_SGF);
@@ -1332,6 +1351,7 @@ static int ahash_update_first(struct ahash_request *req)
	dma_addr_t src_dma;
	u32 options;
	struct ahash_edesc *edesc;
	bool chained = false;
	int ret = 0;
	int sh_len;

@@ -1340,8 +1360,10 @@ static int ahash_update_first(struct ahash_request *req)
	to_hash = req->nbytes - *next_buflen;

	if (to_hash) {
		src_nents = sg_count(req->src, req->nbytes - (*next_buflen));
		dma_map_sg(jrdev, req->src, src_nents ? : 1, DMA_TO_DEVICE);
		src_nents = sg_count(req->src, req->nbytes - (*next_buflen),
				     &chained);
		dma_map_sg_chained(jrdev, req->src, src_nents ? : 1,
				   DMA_TO_DEVICE, chained);
		sec4_sg_bytes = src_nents * sizeof(struct sec4_sg_entry);

		/*
@@ -1357,6 +1379,7 @@ static int ahash_update_first(struct ahash_request *req)
		}

		edesc->src_nents = src_nents;
		edesc->chained = chained;
		edesc->sec4_sg_bytes = sec4_sg_bytes;
		edesc->sec4_sg = (void *)edesc + sizeof(struct ahash_edesc) +
				 DESC_JOB_IO_LEN;
+39 −5
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ sg_to_sec4_sg(struct scatterlist *sg, int sg_count,
		dma_to_sec4_sg_one(sec4_sg_ptr, sg_dma_address(sg),
				   sg_dma_len(sg), offset);
		sec4_sg_ptr++;
		sg = sg_next(sg);
		sg = scatterwalk_sg_next(sg);
		sg_count--;
	}
	return sec4_sg_ptr - 1;
@@ -56,7 +56,8 @@ static inline void sg_to_sec4_sg_last(struct scatterlist *sg, int sg_count,
}

/* count number of elements in scatterlist */
static inline int __sg_count(struct scatterlist *sg_list, int nbytes)
static inline int __sg_count(struct scatterlist *sg_list, int nbytes,
			     bool *chained)
{
	struct scatterlist *sg = sg_list;
	int sg_nents = 0;
@@ -65,7 +66,7 @@ static inline int __sg_count(struct scatterlist *sg_list, int nbytes)
		sg_nents++;
		nbytes -= sg->length;
		if (!sg_is_last(sg) && (sg + 1)->length == 0)
			BUG(); /* Not support chaining */
			*chained = true;
		sg = scatterwalk_sg_next(sg);
	}

@@ -73,9 +74,10 @@ static inline int __sg_count(struct scatterlist *sg_list, int nbytes)
}

/* derive number of elements in scatterlist, but return 0 for 1 */
static inline int sg_count(struct scatterlist *sg_list, int nbytes)
static inline int sg_count(struct scatterlist *sg_list, int nbytes,
			     bool *chained)
{
	int sg_nents = __sg_count(sg_list, nbytes);
	int sg_nents = __sg_count(sg_list, nbytes, chained);

	if (likely(sg_nents == 1))
		return 0;
@@ -83,6 +85,38 @@ static inline int sg_count(struct scatterlist *sg_list, int nbytes)
	return sg_nents;
}

static int dma_map_sg_chained(struct device *dev, struct scatterlist *sg,
			      unsigned int nents, enum dma_data_direction dir,
			      bool chained)
{
	if (unlikely(chained)) {
		int i;
		for (i = 0; i < nents; i++) {
			dma_map_sg(dev, sg, 1, dir);
			sg = scatterwalk_sg_next(sg);
		}
	} else {
		dma_map_sg(dev, sg, nents, dir);
	}
	return nents;
}

static int dma_unmap_sg_chained(struct device *dev, struct scatterlist *sg,
				unsigned int nents, enum dma_data_direction dir,
				bool chained)
{
	if (unlikely(chained)) {
		int i;
		for (i = 0; i < nents; i++) {
			dma_unmap_sg(dev, sg, 1, dir);
			sg = scatterwalk_sg_next(sg);
		}
	} else {
		dma_unmap_sg(dev, sg, nents, dir);
	}
	return nents;
}

/* Copy from len bytes of sg to dest, starting from beginning */
static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len)
{