Commit 79980434 authored by Marcelo Cerri's avatar Marcelo Cerri Committed by Herbert Xu
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crypto: nx - fix limits to sg lists for AES-GCM 



This patch updates the nx-aes-gcm implementation to perform several
hyper calls if needed in order to always respect the length limits for
scatter/gather lists.

Two different limits are considered:

 - "ibm,max-sg-len": maximum number of bytes of each scatter/gather
   list.

 - "ibm,max-sync-cop":
    - The total number of bytes that a scatter/gather list can hold.
    - The maximum number of elements that a scatter/gather list can have.

Reviewed-by: default avatarJoy Latten <jmlatten@linux.vnet.ibm.com>
Signed-off-by: default avatarMarcelo Cerri <mhcerri@linux.vnet.ibm.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 884d981b

drivers/crypto/nx/nx-aes-gcm.c

+136 −66
Original line number Diff line number Diff line
@@ -125,108 +125,167 @@ static int nx_gca(struct nx_crypto_ctx *nx_ctx, 
		  struct aead_request   *req,

		  u8                    *out)

{

	int rc;

	struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;

	int rc = -EINVAL;

	struct scatter_walk walk;

	struct nx_sg *nx_sg = nx_ctx->in_sg;

	unsigned int nbytes = req->assoclen;

	unsigned int processed = 0, to_process;

	u32 max_sg_len;



	if (req->assoclen > nx_ctx->ap->databytelen)

		goto out;



	if (req->assoclen <= AES_BLOCK_SIZE) {

	if (nbytes <= AES_BLOCK_SIZE) {

		scatterwalk_start(&walk, req->assoc);

		scatterwalk_copychunks(out, &walk, req->assoclen,

				       SCATTERWALK_FROM_SG);

		scatterwalk_copychunks(out, &walk, nbytes, SCATTERWALK_FROM_SG);

		scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0);



		rc = 0;

		goto out;

		return 0;

	}



	nx_sg = nx_walk_and_build(nx_sg, nx_ctx->ap->sglen, req->assoc, 0,

				  req->assoclen);

	nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg) * sizeof(struct nx_sg);

	NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_CONTINUATION;



	/* page_limit: number of sg entries that fit on one page */

	max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),

			   nx_ctx->ap->sglen);



	do {

		/*

		 * to_process: the data chunk to process in this update.

		 * This value is bound by sg list limits.

		 */

		to_process = min_t(u64, nbytes - processed,

				   nx_ctx->ap->databytelen);

		to_process = min_t(u64, to_process,

				   NX_PAGE_SIZE * (max_sg_len - 1));



		if ((to_process + processed) < nbytes)

			NX_CPB_FDM(csbcpb_aead) |= NX_FDM_INTERMEDIATE;

		else

			NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_INTERMEDIATE;



		nx_sg = nx_walk_and_build(nx_ctx->in_sg, nx_ctx->ap->sglen,

					  req->assoc, processed, to_process);

		nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg)

					* sizeof(struct nx_sg);



		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,

				req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);

		if (rc)

		goto out;

			return rc;



		memcpy(csbcpb_aead->cpb.aes_gca.in_pat,

				csbcpb_aead->cpb.aes_gca.out_pat,

				AES_BLOCK_SIZE);

		NX_CPB_FDM(csbcpb_aead) |= NX_FDM_CONTINUATION;



		atomic_inc(&(nx_ctx->stats->aes_ops));

		atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes));



		processed += to_process;

	} while (processed < nbytes);



	memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE);

out:



	return rc;

}



static int gcm_aes_nx_crypt(struct aead_request *req, int enc)

static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc,

		     int enc)

{

	int rc;

	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);

	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;

	struct blkcipher_desc desc;

	unsigned int nbytes = req->cryptlen;

	unsigned long irq_flags;

	int rc = -EINVAL;



	spin_lock_irqsave(&nx_ctx->lock, irq_flags);



	if (nbytes > nx_ctx->ap->databytelen)

		goto out;



	desc.info = nx_ctx->priv.gcm.iv;

	/* initialize the counter */

	*(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;



	/* For scenarios where the input message is zero length, AES CTR mode

	 * may be used. Set the source data to be a single block (16B) of all

	 * zeros, and set the input IV value to be the same as the GMAC IV

	 * value. - nx_wb 4.8.1.3 */

	if (nbytes == 0) {

	char src[AES_BLOCK_SIZE] = {};

	struct scatterlist sg;



		desc.tfm = crypto_alloc_blkcipher("ctr(aes)", 0, 0);

		if (IS_ERR(desc.tfm)) {

	desc->tfm = crypto_alloc_blkcipher("ctr(aes)", 0, 0);

	if (IS_ERR(desc->tfm)) {

		rc = -ENOMEM;

		goto out;

	}



		crypto_blkcipher_setkey(desc.tfm, csbcpb->cpb.aes_gcm.key,

	crypto_blkcipher_setkey(desc->tfm, csbcpb->cpb.aes_gcm.key,

		NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_128 ? 16 :

		NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_192 ? 24 : 32);



	sg_init_one(&sg, src, AES_BLOCK_SIZE);

	if (enc)

			crypto_blkcipher_encrypt_iv(&desc, req->dst, &sg,

		rc = crypto_blkcipher_encrypt_iv(desc, req->dst, &sg,

						 AES_BLOCK_SIZE);

	else

			crypto_blkcipher_decrypt_iv(&desc, req->dst, &sg,

		rc = crypto_blkcipher_decrypt_iv(desc, req->dst, &sg,

						 AES_BLOCK_SIZE);

		crypto_free_blkcipher(desc.tfm);

	crypto_free_blkcipher(desc->tfm);



		rc = 0;

		goto out;

out:

	return rc;

}



	desc.tfm = (struct crypto_blkcipher *)req->base.tfm;

static int gcm_aes_nx_crypt(struct aead_request *req, int enc)

{

	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);

	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;

	struct blkcipher_desc desc;

	unsigned int nbytes = req->cryptlen;

	unsigned int processed = 0, to_process;

	unsigned long irq_flags;

	u32 max_sg_len;

	int rc = -EINVAL;



	csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8;

	spin_lock_irqsave(&nx_ctx->lock, irq_flags);



	desc.info = nx_ctx->priv.gcm.iv;

	/* initialize the counter */

	*(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;



	if (nbytes == 0) {

		rc = gcm_empty(req, &desc, enc);

		goto out;

	}



	/* Process associated data */

	csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8;

	if (req->assoclen) {

		rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad);

		if (rc)

			goto out;

	}



	if (enc)

	/* Set flags for encryption */

	NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;

	if (enc) {

		NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;

	else

	} else {

		NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;

		nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));

	}



	csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;

	/* page_limit: number of sg entries that fit on one page */

	max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),

			   nx_ctx->ap->sglen);



	rc = nx_build_sg_lists(nx_ctx, &desc, req->dst, req->src, nbytes, 0,

	do {

		/*

		 * to_process: the data chunk to process in this update.

		 * This value is bound by sg list limits.

		 */

		to_process = min_t(u64, nbytes - processed,

				   nx_ctx->ap->databytelen);

		to_process = min_t(u64, to_process,

				   NX_PAGE_SIZE * (max_sg_len - 1));



		if ((to_process + processed) < nbytes)

			NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;

		else

			NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;



		csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;

		desc.tfm = (struct crypto_blkcipher *) req->base.tfm;

		rc = nx_build_sg_lists(nx_ctx, &desc, req->dst,

				       req->src, to_process, processed,

				       csbcpb->cpb.aes_gcm.iv_or_cnt);

		if (rc)

			goto out;
@@ -236,10 +295,21 @@ static int gcm_aes_nx_crypt(struct aead_request *req, int enc) 
		if (rc)

			goto out;



		memcpy(desc.info, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE);

		memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,

			csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);

		memcpy(csbcpb->cpb.aes_gcm.in_s0,

			csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);



		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;



		atomic_inc(&(nx_ctx->stats->aes_ops));

		atomic64_add(csbcpb->csb.processed_byte_count,

			     &(nx_ctx->stats->aes_bytes));



		processed += to_process;

	} while (processed < nbytes);



	if (enc) {

		/* copy out the auth tag */

		scatterwalk_map_and_copy(csbcpb->cpb.aes_gcm.out_pat_or_mac,

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