crypto: caam - add Derived Key Protocol (DKP) support

Offload split key generation in CAAM engine, using DKP.
DKP is supported starting with Era 6.

Note that the way assoclen is transmitted from the job descriptor
to the shared descriptor changes - DPOVRD register is used instead
of MATH3 (where available), since DKP protocol thrashes the MATH
registers.

The replacement of MDHA split key generation with DKP has the side
effect of the crypto engine writing the authentication key, and thus
the DMA mapping direction for the buffer holding the key has to change
from DMA_TO_DEVICE to DMA_BIDIRECTIONAL.
There are two cases:
-key is inlined in descriptor - descriptor buffer mapping changes
-key is referenced - key buffer mapping changes

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 43 insertions, 11 deletions

diff --git a/drivers/crypto/caam/caamalg_qi.c b/drivers/crypto/caam/caamalg_qi.c
index b45401786530..4aecc9435f69 100644
--- a/drivers/crypto/caam/caamalg_qi.c
+++ b/drivers/crypto/caam/caamalg_qi.c
@@ -53,6 +53,7 @@ struct caam_ctx {
 	u32 sh_desc_givenc[DESC_MAX_USED_LEN];
 	u8 key[CAAM_MAX_KEY_SIZE];
 	dma_addr_t key_dma;
+	enum dma_data_direction dir;
 	struct alginfo adata;
 	struct alginfo cdata;
 	unsigned int authsize;
@@ -74,6 +75,7 @@ static int aead_set_sh_desc(struct crypto_aead *aead)
 	const bool ctr_mode = ((ctx->cdata.algtype & OP_ALG_AAI_MASK) ==
 			       OP_ALG_AAI_CTR_MOD128);
 	const bool is_rfc3686 = alg->caam.rfc3686;
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctx->jrdev->parent);
 
 	if (!ctx->cdata.keylen || !ctx->authsize)
 		return 0;
@@ -124,7 +126,7 @@ static int aead_set_sh_desc(struct crypto_aead *aead)
 
 	cnstr_shdsc_aead_encap(ctx->sh_desc_enc, &ctx->cdata, &ctx->adata,
 			       ivsize, ctx->authsize, is_rfc3686, nonce,
-			       ctx1_iv_off, true);
+			       ctx1_iv_off, true, ctrlpriv->era);
 
 skip_enc:
 	/* aead_decrypt shared descriptor */
@@ -149,7 +151,8 @@ skip_enc:
 
 	cnstr_shdsc_aead_decap(ctx->sh_desc_dec, &ctx->cdata, &ctx->adata,
 			       ivsize, ctx->authsize, alg->caam.geniv,
-			       is_rfc3686, nonce, ctx1_iv_off, true);
+			       is_rfc3686, nonce, ctx1_iv_off, true,
+			       ctrlpriv->era);
 
 	if (!alg->caam.geniv)
 		goto skip_givenc;
@@ -176,7 +179,7 @@ skip_enc:
 
 	cnstr_shdsc_aead_givencap(ctx->sh_desc_enc, &ctx->cdata, &ctx->adata,
 				  ivsize, ctx->authsize, is_rfc3686, nonce,
-				  ctx1_iv_off, true);
+				  ctx1_iv_off, true, ctrlpriv->era);
 
 skip_givenc:
 	return 0;
@@ -197,6 +200,7 @@ static int aead_setkey(struct crypto_aead *aead, const u8 *key,
 {
 	struct caam_ctx *ctx = crypto_aead_ctx(aead);
 	struct device *jrdev = ctx->jrdev;
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(jrdev->parent);
 	struct crypto_authenc_keys keys;
 	int ret = 0;
 
@@ -211,6 +215,27 @@ static int aead_setkey(struct crypto_aead *aead, const u8 *key,
 		       DUMP_PREFIX_ADDRESS, 16, 4, key, keylen, 1);
 #endif
 
+	/*
+	 * If DKP is supported, use it in the shared descriptor to generate
+	 * the split key.
+	 */
+	if (ctrlpriv->era >= 6) {
+		ctx->adata.keylen = keys.authkeylen;
+		ctx->adata.keylen_pad = split_key_len(ctx->adata.algtype &
+						      OP_ALG_ALGSEL_MASK);
+
+		if (ctx->adata.keylen_pad + keys.enckeylen > CAAM_MAX_KEY_SIZE)
+			goto badkey;
+
+		memcpy(ctx->key, keys.authkey, keys.authkeylen);
+		memcpy(ctx->key + ctx->adata.keylen_pad, keys.enckey,
+		       keys.enckeylen);
+		dma_sync_single_for_device(jrdev, ctx->key_dma,
+					   ctx->adata.keylen_pad +
+					   keys.enckeylen, ctx->dir);
+		goto skip_split_key;
+	}
+
 	ret = gen_split_key(jrdev, ctx->key, &ctx->adata, keys.authkey,
 			    keys.authkeylen, CAAM_MAX_KEY_SIZE -
 			    keys.enckeylen);
@@ -220,13 +245,14 @@ static int aead_setkey(struct crypto_aead *aead, const u8 *key,
 	/* postpend encryption key to auth split key */
 	memcpy(ctx->key + ctx->adata.keylen_pad, keys.enckey, keys.enckeylen);
 	dma_sync_single_for_device(jrdev, ctx->key_dma, ctx->adata.keylen_pad +
-				   keys.enckeylen, DMA_TO_DEVICE);
+				   keys.enckeylen, ctx->dir);
 #ifdef DEBUG
 	print_hex_dump(KERN_ERR, "ctx.key@" __stringify(__LINE__)": ",
 		       DUMP_PREFIX_ADDRESS, 16, 4, ctx->key,
 		       ctx->adata.keylen_pad + keys.enckeylen, 1);
 #endif
 
+skip_split_key:
 	ctx->cdata.keylen = keys.enckeylen;
 
 	ret = aead_set_sh_desc(aead);
@@ -2119,7 +2145,8 @@ struct caam_crypto_alg {
 	struct caam_alg_entry caam;
 };
 
-static int caam_init_common(struct caam_ctx *ctx, struct caam_alg_entry *caam)
+static int caam_init_common(struct caam_ctx *ctx, struct caam_alg_entry *caam,
+			    bool uses_dkp)
 {
 	struct caam_drv_private *priv;
 
@@ -2133,8 +2160,14 @@ static int caam_init_common(struct caam_ctx *ctx, struct caam_alg_entry *caam)
 		return PTR_ERR(ctx->jrdev);
 	}
 
+	priv = dev_get_drvdata(ctx->jrdev->parent);
+	if (priv->era >= 6 && uses_dkp)
+		ctx->dir = DMA_BIDIRECTIONAL;
+	else
+		ctx->dir = DMA_TO_DEVICE;
+
 	ctx->key_dma = dma_map_single(ctx->jrdev, ctx->key, sizeof(ctx->key),
-				      DMA_TO_DEVICE);
+				      ctx->dir);
 	if (dma_mapping_error(ctx->jrdev, ctx->key_dma)) {
 		dev_err(ctx->jrdev, "unable to map key\n");
 		caam_jr_free(ctx->jrdev);
@@ -2145,7 +2178,6 @@ static int caam_init_common(struct caam_ctx *ctx, struct caam_alg_entry *caam)
 	ctx->cdata.algtype = OP_TYPE_CLASS1_ALG | caam->class1_alg_type;
 	ctx->adata.algtype = OP_TYPE_CLASS2_ALG | caam->class2_alg_type;
 
-	priv = dev_get_drvdata(ctx->jrdev->parent);
 	ctx->qidev = priv->qidev;
 
 	spin_lock_init(&ctx->lock);
@@ -2163,7 +2195,7 @@ static int caam_cra_init(struct crypto_tfm *tfm)
 							crypto_alg);
 	struct caam_ctx *ctx = crypto_tfm_ctx(tfm);
 
-	return caam_init_common(ctx, &caam_alg->caam);
+	return caam_init_common(ctx, &caam_alg->caam, false);
 }
 
 static int caam_aead_init(struct crypto_aead *tfm)
@@ -2173,7 +2205,8 @@ static int caam_aead_init(struct crypto_aead *tfm)
 						      aead);
 	struct caam_ctx *ctx = crypto_aead_ctx(tfm);
 
-	return caam_init_common(ctx, &caam_alg->caam);
+	return caam_init_common(ctx, &caam_alg->caam,
+				alg->setkey == aead_setkey);
 }
 
 static void caam_exit_common(struct caam_ctx *ctx)
@@ -2182,8 +2215,7 @@ static void caam_exit_common(struct caam_ctx *ctx)
 	caam_drv_ctx_rel(ctx->drv_ctx[DECRYPT]);
 	caam_drv_ctx_rel(ctx->drv_ctx[GIVENCRYPT]);
 
-	dma_unmap_single(ctx->jrdev, ctx->key_dma, sizeof(ctx->key),
-			 DMA_TO_DEVICE);
+	dma_unmap_single(ctx->jrdev, ctx->key_dma, sizeof(ctx->key), ctx->dir);
 
 	caam_jr_free(ctx->jrdev);
 }