crypto: atmel-authenc - add support to authenc(hmac(shaX), Y(aes)) modes

This patchs allows to combine the AES and SHA hardware accelerators on
some Atmel SoCs. Doing so, AES blocks are only written to/read from the
AES hardware. Those blocks are also transferred from the AES to the SHA
accelerator internally, without additionnal accesses to the system busses.

Hence, the AES and SHA accelerators work in parallel to process all the
data blocks, instead of serializing the process by (de)crypting those
blocks first then authenticating them after like the generic
crypto/authenc.c driver does.

Of course, both the AES and SHA hardware accelerators need to be available
before we can start to process the data blocks. Hence we use their crypto
request queue to synchronize both drivers.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 330 insertions, 14 deletions

diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c
index 78c3c02e4483..cc5294dbead4 100644
--- a/drivers/crypto/atmel-sha.c
+++ b/drivers/crypto/atmel-sha.c
@@ -41,6 +41,7 @@
 #include <crypto/internal/hash.h>
 #include <linux/platform_data/crypto-atmel.h>
 #include "atmel-sha-regs.h"
+#include "atmel-authenc.h"
 
 /* SHA flags */
 #define SHA_FLAGS_BUSY			BIT(0)
@@ -52,19 +53,6 @@
 #define SHA_FLAGS_DMA_READY		BIT(6)
 
 /* bits[11:8] are reserved. */
-#define SHA_FLAGS_ALGO_MASK	SHA_MR_ALGO_MASK
-#define SHA_FLAGS_SHA1		SHA_MR_ALGO_SHA1
-#define SHA_FLAGS_SHA256	SHA_MR_ALGO_SHA256
-#define SHA_FLAGS_SHA384	SHA_MR_ALGO_SHA384
-#define SHA_FLAGS_SHA512	SHA_MR_ALGO_SHA512
-#define SHA_FLAGS_SHA224	SHA_MR_ALGO_SHA224
-#define SHA_FLAGS_HMAC		SHA_MR_HMAC
-#define SHA_FLAGS_HMAC_SHA1	(SHA_FLAGS_HMAC | SHA_FLAGS_SHA1)
-#define SHA_FLAGS_HMAC_SHA256	(SHA_FLAGS_HMAC | SHA_FLAGS_SHA256)
-#define SHA_FLAGS_HMAC_SHA384	(SHA_FLAGS_HMAC | SHA_FLAGS_SHA384)
-#define SHA_FLAGS_HMAC_SHA512	(SHA_FLAGS_HMAC | SHA_FLAGS_SHA512)
-#define SHA_FLAGS_HMAC_SHA224	(SHA_FLAGS_HMAC | SHA_FLAGS_SHA224)
-#define SHA_FLAGS_MODE_MASK	(SHA_FLAGS_HMAC | SHA_FLAGS_ALGO_MASK)
 
 #define SHA_FLAGS_FINUP		BIT(16)
 #define SHA_FLAGS_SG		BIT(17)
@@ -156,6 +144,7 @@ struct atmel_sha_dev {
 	struct crypto_queue	queue;
 	struct ahash_request	*req;
 	bool			is_async;
+	bool			force_complete;
 	atmel_sha_fn_t		resume;
 	atmel_sha_fn_t		cpu_transfer_complete;
 
@@ -198,7 +187,7 @@ static inline int atmel_sha_complete(struct atmel_sha_dev *dd, int err)
 
 	clk_disable(dd->iclk);
 
-	if (dd->is_async && req->base.complete)
+	if ((dd->is_async || dd->force_complete) && req->base.complete)
 		req->base.complete(&req->base, err);
 
 	/* handle new request */
@@ -992,6 +981,7 @@ static int atmel_sha_handle_queue(struct atmel_sha_dev *dd,
 	dd->req = ahash_request_cast(async_req);
 	start_async = (dd->req != req);
 	dd->is_async = start_async;
+	dd->force_complete = false;
 
 	/* WARNING: ctx->start() MAY change dd->is_async. */
 	err = ctx->start(dd);
@@ -2100,6 +2090,332 @@ static struct ahash_alg sha_hmac_algs[] = {
 },
 };
 
+#ifdef CONFIG_CRYPTO_DEV_ATMEL_AUTHENC
+/* authenc functions */
+
+static int atmel_sha_authenc_init2(struct atmel_sha_dev *dd);
+static int atmel_sha_authenc_init_done(struct atmel_sha_dev *dd);
+static int atmel_sha_authenc_final_done(struct atmel_sha_dev *dd);
+
+
+struct atmel_sha_authenc_ctx {
+	struct crypto_ahash	*tfm;
+};
+
+struct atmel_sha_authenc_reqctx {
+	struct atmel_sha_reqctx	base;
+
+	atmel_aes_authenc_fn_t	cb;
+	struct atmel_aes_dev	*aes_dev;
+
+	/* _init() parameters. */
+	struct scatterlist	*assoc;
+	u32			assoclen;
+	u32			textlen;
+
+	/* _final() parameters. */
+	u32			*digest;
+	unsigned int		digestlen;
+};
+
+static void atmel_sha_authenc_complete(struct crypto_async_request *areq,
+				       int err)
+{
+	struct ahash_request *req = areq->data;
+	struct atmel_sha_authenc_reqctx *authctx  = ahash_request_ctx(req);
+
+	authctx->cb(authctx->aes_dev, err, authctx->base.dd->is_async);
+}
+
+static int atmel_sha_authenc_start(struct atmel_sha_dev *dd)
+{
+	struct ahash_request *req = dd->req;
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	int err;
+
+	/*
+	 * Force atmel_sha_complete() to call req->base.complete(), ie
+	 * atmel_sha_authenc_complete(), which in turn calls authctx->cb().
+	 */
+	dd->force_complete = true;
+
+	err = atmel_sha_hw_init(dd);
+	return authctx->cb(authctx->aes_dev, err, dd->is_async);
+}
+
+bool atmel_sha_authenc_is_ready(void)
+{
+	struct atmel_sha_ctx dummy;
+
+	dummy.dd = NULL;
+	return (atmel_sha_find_dev(&dummy) != NULL);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_is_ready);
+
+unsigned int atmel_sha_authenc_get_reqsize(void)
+{
+	return sizeof(struct atmel_sha_authenc_reqctx);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_get_reqsize);
+
+struct atmel_sha_authenc_ctx *atmel_sha_authenc_spawn(unsigned long mode)
+{
+	struct atmel_sha_authenc_ctx *auth;
+	struct crypto_ahash *tfm;
+	struct atmel_sha_ctx *tctx;
+	const char *name;
+	int err = -EINVAL;
+
+	switch (mode & SHA_FLAGS_MODE_MASK) {
+	case SHA_FLAGS_HMAC_SHA1:
+		name = "atmel-hmac-sha1";
+		break;
+
+	case SHA_FLAGS_HMAC_SHA224:
+		name = "atmel-hmac-sha224";
+		break;
+
+	case SHA_FLAGS_HMAC_SHA256:
+		name = "atmel-hmac-sha256";
+		break;
+
+	case SHA_FLAGS_HMAC_SHA384:
+		name = "atmel-hmac-sha384";
+		break;
+
+	case SHA_FLAGS_HMAC_SHA512:
+		name = "atmel-hmac-sha512";
+		break;
+
+	default:
+		goto error;
+	}
+
+	tfm = crypto_alloc_ahash(name,
+				 CRYPTO_ALG_TYPE_AHASH,
+				 CRYPTO_ALG_TYPE_AHASH_MASK);
+	if (IS_ERR(tfm)) {
+		err = PTR_ERR(tfm);
+		goto error;
+	}
+	tctx = crypto_ahash_ctx(tfm);
+	tctx->start = atmel_sha_authenc_start;
+	tctx->flags = mode;
+
+	auth = kzalloc(sizeof(*auth), GFP_KERNEL);
+	if (!auth) {
+		err = -ENOMEM;
+		goto err_free_ahash;
+	}
+	auth->tfm = tfm;
+
+	return auth;
+
+err_free_ahash:
+	crypto_free_ahash(tfm);
+error:
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_spawn);
+
+void atmel_sha_authenc_free(struct atmel_sha_authenc_ctx *auth)
+{
+	if (auth)
+		crypto_free_ahash(auth->tfm);
+	kfree(auth);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_free);
+
+int atmel_sha_authenc_setkey(struct atmel_sha_authenc_ctx *auth,
+			     const u8 *key, unsigned int keylen,
+			     u32 *flags)
+{
+	struct crypto_ahash *tfm = auth->tfm;
+	int err;
+
+	crypto_ahash_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_ahash_set_flags(tfm, *flags & CRYPTO_TFM_REQ_MASK);
+	err = crypto_ahash_setkey(tfm, key, keylen);
+	*flags = crypto_ahash_get_flags(tfm);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_setkey);
+
+int atmel_sha_authenc_schedule(struct ahash_request *req,
+			       struct atmel_sha_authenc_ctx *auth,
+			       atmel_aes_authenc_fn_t cb,
+			       struct atmel_aes_dev *aes_dev)
+{
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	struct atmel_sha_reqctx *ctx = &authctx->base;
+	struct crypto_ahash *tfm = auth->tfm;
+	struct atmel_sha_ctx *tctx = crypto_ahash_ctx(tfm);
+	struct atmel_sha_dev *dd;
+
+	/* Reset request context (MUST be done first). */
+	memset(authctx, 0, sizeof(*authctx));
+
+	/* Get SHA device. */
+	dd = atmel_sha_find_dev(tctx);
+	if (!dd)
+		return cb(aes_dev, -ENODEV, false);
+
+	/* Init request context. */
+	ctx->dd = dd;
+	ctx->buflen = SHA_BUFFER_LEN;
+	authctx->cb = cb;
+	authctx->aes_dev = aes_dev;
+	ahash_request_set_tfm(req, tfm);
+	ahash_request_set_callback(req, 0, atmel_sha_authenc_complete, req);
+
+	return atmel_sha_handle_queue(dd, req);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_schedule);
+
+int atmel_sha_authenc_init(struct ahash_request *req,
+			   struct scatterlist *assoc, unsigned int assoclen,
+			   unsigned int textlen,
+			   atmel_aes_authenc_fn_t cb,
+			   struct atmel_aes_dev *aes_dev)
+{
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	struct atmel_sha_reqctx *ctx = &authctx->base;
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
+	struct atmel_sha_dev *dd = ctx->dd;
+
+	if (unlikely(!IS_ALIGNED(assoclen, sizeof(u32))))
+		return atmel_sha_complete(dd, -EINVAL);
+
+	authctx->cb = cb;
+	authctx->aes_dev = aes_dev;
+	authctx->assoc = assoc;
+	authctx->assoclen = assoclen;
+	authctx->textlen = textlen;
+
+	ctx->flags = hmac->base.flags;
+	return atmel_sha_hmac_setup(dd, atmel_sha_authenc_init2);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_init);
+
+static int atmel_sha_authenc_init2(struct atmel_sha_dev *dd)
+{
+	struct ahash_request *req = dd->req;
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	struct atmel_sha_reqctx *ctx = &authctx->base;
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
+	size_t hs = ctx->hash_size;
+	size_t i, num_words = hs / sizeof(u32);
+	u32 mr, msg_size;
+
+	atmel_sha_write(dd, SHA_CR, SHA_CR_WUIHV);
+	for (i = 0; i < num_words; ++i)
+		atmel_sha_write(dd, SHA_REG_DIN(i), hmac->ipad[i]);
+
+	atmel_sha_write(dd, SHA_CR, SHA_CR_WUIEHV);
+	for (i = 0; i < num_words; ++i)
+		atmel_sha_write(dd, SHA_REG_DIN(i), hmac->opad[i]);
+
+	mr = (SHA_MR_MODE_IDATAR0 |
+	      SHA_MR_HMAC |
+	      SHA_MR_DUALBUFF);
+	mr |= ctx->flags & SHA_FLAGS_ALGO_MASK;
+	atmel_sha_write(dd, SHA_MR, mr);
+
+	msg_size = authctx->assoclen + authctx->textlen;
+	atmel_sha_write(dd, SHA_MSR, msg_size);
+	atmel_sha_write(dd, SHA_BCR, msg_size);
+
+	atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);
+
+	/* Process assoc data. */
+	return atmel_sha_cpu_start(dd, authctx->assoc, authctx->assoclen,
+				   true, false,
+				   atmel_sha_authenc_init_done);
+}
+
+static int atmel_sha_authenc_init_done(struct atmel_sha_dev *dd)
+{
+	struct ahash_request *req = dd->req;
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+
+	return authctx->cb(authctx->aes_dev, 0, dd->is_async);
+}
+
+int atmel_sha_authenc_final(struct ahash_request *req,
+			    u32 *digest, unsigned int digestlen,
+			    atmel_aes_authenc_fn_t cb,
+			    struct atmel_aes_dev *aes_dev)
+{
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	struct atmel_sha_reqctx *ctx = &authctx->base;
+	struct atmel_sha_dev *dd = ctx->dd;
+
+	switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
+	case SHA_FLAGS_SHA1:
+		authctx->digestlen = SHA1_DIGEST_SIZE;
+		break;
+
+	case SHA_FLAGS_SHA224:
+		authctx->digestlen = SHA224_DIGEST_SIZE;
+		break;
+
+	case SHA_FLAGS_SHA256:
+		authctx->digestlen = SHA256_DIGEST_SIZE;
+		break;
+
+	case SHA_FLAGS_SHA384:
+		authctx->digestlen = SHA384_DIGEST_SIZE;
+		break;
+
+	case SHA_FLAGS_SHA512:
+		authctx->digestlen = SHA512_DIGEST_SIZE;
+		break;
+
+	default:
+		return atmel_sha_complete(dd, -EINVAL);
+	}
+	if (authctx->digestlen > digestlen)
+		authctx->digestlen = digestlen;
+
+	authctx->cb = cb;
+	authctx->aes_dev = aes_dev;
+	authctx->digest = digest;
+	return atmel_sha_wait_for_data_ready(dd,
+					     atmel_sha_authenc_final_done);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_final);
+
+static int atmel_sha_authenc_final_done(struct atmel_sha_dev *dd)
+{
+	struct ahash_request *req = dd->req;
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	size_t i, num_words = authctx->digestlen / sizeof(u32);
+
+	for (i = 0; i < num_words; ++i)
+		authctx->digest[i] = atmel_sha_read(dd, SHA_REG_DIGEST(i));
+
+	return atmel_sha_complete(dd, 0);
+}
+
+void atmel_sha_authenc_abort(struct ahash_request *req)
+{
+	struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
+	struct atmel_sha_reqctx *ctx = &authctx->base;
+	struct atmel_sha_dev *dd = ctx->dd;
+
+	/* Prevent atmel_sha_complete() from calling req->base.complete(). */
+	dd->is_async = false;
+	dd->force_complete = false;
+	(void)atmel_sha_complete(dd, 0);
+}
+EXPORT_SYMBOL_GPL(atmel_sha_authenc_abort);
+
+#endif /* CONFIG_CRYPTO_DEV_ATMEL_AUTHENC */
+
+
 static void atmel_sha_unregister_algs(struct atmel_sha_dev *dd)
 {
 	int i;