[Patch v2 6/7] crypto: qce: common: Add support for AEAD algorithms

[Thara Gopinath]

Add register programming sequence for enabling AEAD
algorithms on the Qualcomm crypto engine.

Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
---

v1->v2:
	- Minor fixes like removing not needed initializing of variables
	  and using bool values in lieu of 0 and 1 as pointed out by Bjorn.
	- Introduced qce_be32_to_cpu_array which converts the u8 string in big
	  endian order to array of u32 and returns back total number of words,
	  as per Bjorn's review comments. Presently this function is used only by
	  qce_setup_regs_aead to format keys, iv and nonce. cipher and hash 
	  algorithms can be made to use this function as a separate clean up patch.

 drivers/crypto/qce/common.c | 164 +++++++++++++++++++++++++++++++++++-
 1 file changed, 162 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/qce/common.c b/drivers/crypto/qce/common.c
index 7b3d6caec1b2..ffbf866842a3 100644
--- a/drivers/crypto/qce/common.c
+++ b/drivers/crypto/qce/common.c
@@ -15,6 +15,16 @@
 #include "core.h"
 #include "regs-v5.h"
 #include "sha.h"
+#include "aead.h"
+
+static const u32 std_iv_sha1[SHA256_DIGEST_SIZE / sizeof(u32)] = {
+	SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4, 0, 0, 0
+};
+
+static const u32 std_iv_sha256[SHA256_DIGEST_SIZE / sizeof(u32)] = {
+	SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3,
+	SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7
+};
 
 static inline u32 qce_read(struct qce_device *qce, u32 offset)
 {
@@ -76,6 +86,21 @@ void qce_cpu_to_be32p_array(__be32 *dst, const u8 *src, unsigned int len)
 	}
 }
 
+static unsigned int qce_be32_to_cpu_array(u32 *dst, const u8 *src, unsigned int len)
+{
+	__be32 *d = (__be32 *)dst;
+	const u8 *s = src;
+	unsigned int n;
+
+	n = len / sizeof(u32);
+	for (; n > 0; n--) {
+		*d = cpu_to_be32p((const __u32 *)s);
+		s += sizeof(u32);
+		d++;
+	}
+	return DIV_ROUND_UP(len, sizeof(u32));
+}
+
 static void qce_setup_config(struct qce_device *qce)
 {
 	u32 config;
@@ -96,7 +121,7 @@ static inline void qce_crypto_go(struct qce_device *qce, bool result_dump)
 		qce_write(qce, REG_GOPROC, BIT(GO_SHIFT));
 }
 
-#ifdef CONFIG_CRYPTO_DEV_QCE_SHA
+#if defined(CONFIG_CRYPTO_DEV_QCE_SHA) || defined(CONFIG_CRYPTO_DEV_QCE_AEAD)
 static u32 qce_auth_cfg(unsigned long flags, u32 key_size, u32 auth_size)
 {
 	u32 cfg = 0;
@@ -139,7 +164,9 @@ static u32 qce_auth_cfg(unsigned long flags, u32 key_size, u32 auth_size)
 
 	return cfg;
 }
+#endif
 
+#ifdef CONFIG_CRYPTO_DEV_QCE_SHA
 static int qce_setup_regs_ahash(struct crypto_async_request *async_req)
 {
 	struct ahash_request *req = ahash_request_cast(async_req);
@@ -225,7 +252,7 @@ static int qce_setup_regs_ahash(struct crypto_async_request *async_req)
 }
 #endif
 
-#ifdef CONFIG_CRYPTO_DEV_QCE_SKCIPHER
+#if defined(CONFIG_CRYPTO_DEV_QCE_SKCIPHER) || defined(CONFIG_CRYPTO_DEV_QCE_AEAD)
 static u32 qce_encr_cfg(unsigned long flags, u32 aes_key_size)
 {
 	u32 cfg = 0;
@@ -271,7 +298,9 @@ static u32 qce_encr_cfg(unsigned long flags, u32 aes_key_size)
 
 	return cfg;
 }
+#endif
 
+#ifdef CONFIG_CRYPTO_DEV_QCE_SKCIPHER
 static void qce_xts_swapiv(__be32 *dst, const u8 *src, unsigned int ivsize)
 {
 	u8 swap[QCE_AES_IV_LENGTH];
@@ -386,6 +415,133 @@ static int qce_setup_regs_skcipher(struct crypto_async_request *async_req)
 }
 #endif
 
+#ifdef CONFIG_CRYPTO_DEV_QCE_AEAD
+static int qce_setup_regs_aead(struct crypto_async_request *async_req)
+{
+	struct aead_request *req = aead_request_cast(async_req);
+	struct qce_aead_reqctx *rctx = aead_request_ctx(req);
+	struct qce_aead_ctx *ctx = crypto_tfm_ctx(async_req->tfm);
+	struct qce_alg_template *tmpl = to_aead_tmpl(crypto_aead_reqtfm(req));
+	struct qce_device *qce = tmpl->qce;
+	u32 enckey[QCE_MAX_CIPHER_KEY_SIZE / sizeof(u32)] = {0};
+	u32 enciv[QCE_MAX_IV_SIZE / sizeof(u32)] = {0};
+	u32 authkey[QCE_SHA_HMAC_KEY_SIZE / sizeof(u32)] = {0};
+	u32 authiv[SHA256_DIGEST_SIZE / sizeof(u32)] = {0};
+	u32 authnonce[QCE_MAX_NONCE / sizeof(u32)] = {0};
+	unsigned int enc_keylen = ctx->enc_keylen;
+	unsigned int auth_keylen = ctx->auth_keylen;
+	unsigned int enc_ivsize = rctx->ivsize;
+	unsigned int auth_ivsize;
+	unsigned int enckey_words, enciv_words;
+	unsigned int authkey_words, authiv_words, authnonce_words;
+	unsigned long flags = rctx->flags;
+	u32 encr_cfg, auth_cfg, config, totallen;
+	u32 *iv_last_word;
+
+	qce_setup_config(qce);
+
+	/* Write encryption key */
+	enckey_words = qce_be32_to_cpu_array(enckey, ctx->enc_key, enc_keylen);
+	qce_write_array(qce, REG_ENCR_KEY0, (u32 *)enckey, enckey_words);
+
+	/* Write encryption iv */
+	enciv_words = qce_be32_to_cpu_array(enciv, rctx->iv, enc_ivsize);
+	qce_write_array(qce, REG_CNTR0_IV0, (u32 *)enciv, enciv_words);
+
+	if (IS_CCM(rctx->flags)) {
+		iv_last_word = (u32 *)&enciv[enciv_words - 1];
+		qce_write(qce, REG_CNTR3_IV3, (*iv_last_word) + 1);
+		qce_write_array(qce, REG_ENCR_CCM_INT_CNTR0, (u32 *)enciv, enciv_words);
+		qce_write(qce, REG_CNTR_MASK, ~0);
+		qce_write(qce, REG_CNTR_MASK0, ~0);
+		qce_write(qce, REG_CNTR_MASK1, ~0);
+		qce_write(qce, REG_CNTR_MASK2, ~0);
+	}
+
+	/* Clear authentication IV and KEY registers of previous values */
+	qce_clear_array(qce, REG_AUTH_IV0, 16);
+	qce_clear_array(qce, REG_AUTH_KEY0, 16);
+
+	/* Clear byte count */
+	qce_clear_array(qce, REG_AUTH_BYTECNT0, 4);
+
+	/* Write authentication key */
+	authkey_words = qce_be32_to_cpu_array(authkey, ctx->auth_key, auth_keylen);
+	qce_write_array(qce, REG_AUTH_KEY0, (u32 *)authkey, authkey_words);
+
+	/* Write initial authentication IV only for HMAC algorithms */
+	if (IS_SHA_HMAC(rctx->flags)) {
+		/* Write default authentication iv */
+		if (IS_SHA1_HMAC(rctx->flags)) {
+			auth_ivsize = SHA1_DIGEST_SIZE;
+			memcpy(authiv, std_iv_sha1, auth_ivsize);
+		} else if (IS_SHA256_HMAC(rctx->flags)) {
+			auth_ivsize = SHA256_DIGEST_SIZE;
+			memcpy(authiv, std_iv_sha256, auth_ivsize);
+		}
+		authiv_words = auth_ivsize / sizeof(u32);
+		qce_write_array(qce, REG_AUTH_IV0, (u32 *)authiv, authiv_words);
+	}
+
+	/* Write nonce for CCM algorithms */
+	if (IS_CCM(rctx->flags)) {
+		authnonce_words = qce_be32_to_cpu_array(authnonce, rctx->ccm_nonce, QCE_MAX_NONCE);
+		qce_write_array(qce, REG_AUTH_INFO_NONCE0, (u32 *)authnonce, authnonce_words);
+	}
+
+	/* Set up ENCR_SEG_CFG */
+	encr_cfg = qce_encr_cfg(flags, enc_keylen);
+	if (IS_ENCRYPT(flags))
+		encr_cfg |= BIT(ENCODE_SHIFT);
+	qce_write(qce, REG_ENCR_SEG_CFG, encr_cfg);
+
+	/* Set up AUTH_SEG_CFG */
+	auth_cfg = qce_auth_cfg(rctx->flags, auth_keylen, ctx->authsize);
+	auth_cfg |= BIT(AUTH_LAST_SHIFT);
+	auth_cfg |= BIT(AUTH_FIRST_SHIFT);
+	if (IS_ENCRYPT(flags)) {
+		if (IS_CCM(rctx->flags))
+			auth_cfg |= AUTH_POS_BEFORE << AUTH_POS_SHIFT;
+		else
+			auth_cfg |= AUTH_POS_AFTER << AUTH_POS_SHIFT;
+	} else {
+		if (IS_CCM(rctx->flags))
+			auth_cfg |= AUTH_POS_AFTER << AUTH_POS_SHIFT;
+		else
+			auth_cfg |= AUTH_POS_BEFORE << AUTH_POS_SHIFT;
+	}
+	qce_write(qce, REG_AUTH_SEG_CFG, auth_cfg);
+
+	totallen = rctx->cryptlen + rctx->assoclen;
+
+	/* Set the encryption size and start offset */
+	if (IS_CCM(rctx->flags) && IS_DECRYPT(rctx->flags))
+		qce_write(qce, REG_ENCR_SEG_SIZE, rctx->cryptlen + ctx->authsize);
+	else
+		qce_write(qce, REG_ENCR_SEG_SIZE, rctx->cryptlen);
+	qce_write(qce, REG_ENCR_SEG_START, rctx->assoclen & 0xffff);
+
+	/* Set the authentication size and start offset */
+	qce_write(qce, REG_AUTH_SEG_SIZE, totallen);
+	qce_write(qce, REG_AUTH_SEG_START, 0);
+
+	/* Write total length */
+	if (IS_CCM(rctx->flags) && IS_DECRYPT(rctx->flags))
+		qce_write(qce, REG_SEG_SIZE, totallen + ctx->authsize);
+	else
+		qce_write(qce, REG_SEG_SIZE, totallen);
+
+	/* get little endianness */
+	config = qce_config_reg(qce, 1);
+	qce_write(qce, REG_CONFIG, config);
+
+	/* Start the process */
+	qce_crypto_go(qce, !IS_CCM(flags));
+
+	return 0;
+}
+#endif
+
 int qce_start(struct crypto_async_request *async_req, u32 type)
 {
 	switch (type) {
@@ -396,6 +552,10 @@ int qce_start(struct crypto_async_request *async_req, u32 type)
 #ifdef CONFIG_CRYPTO_DEV_QCE_SHA
 	case CRYPTO_ALG_TYPE_AHASH:
 		return qce_setup_regs_ahash(async_req);
+#endif
+#ifdef CONFIG_CRYPTO_DEV_QCE_AEAD
+	case CRYPTO_ALG_TYPE_AEAD:
+		return qce_setup_regs_aead(async_req);
 #endif
 	default:
 		return -EINVAL;
-- 
2.25.1