[2/6] crypto: hash - Add request chaining API

diff --git a/crypto/ahash.c b/crypto/ahash.c
index c8e7327c6949..e1ee18deca67 100644
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -28,11 +28,19 @@ 
 #define CRYPTO_ALG_TYPE_AHASH_MASK	0x0000000e
 
 struct ahash_save_req_state {
-	struct ahash_request *req;
+	struct list_head head;
+	struct ahash_request *req0;
+	struct ahash_request *cur;
+	int (*op)(struct ahash_request *req);
 	crypto_completion_t compl;
 	void *data;
 };
 
+static void ahash_reqchain_done(void *data, int err);
+static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt);
+static void ahash_restore_req(struct ahash_request *req);
+static int ahash_def_finup(struct ahash_request *req);
+
 /*
  * For an ahash tfm that is using an shash algorithm (instead of an ahash
  * algorithm), this returns the underlying shash tfm.
@@ -256,24 +264,150 @@  int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 
+static int ahash_reqchain_finish(struct ahash_save_req_state *state,
+				 int err, u32 mask)
+{
+	struct ahash_request *req0 = state->req0;
+	struct ahash_request *req = state->cur;
+	struct ahash_request *n;
+
+	req->base.err = err;
+
+	if (req == req0)
+		INIT_LIST_HEAD(&req->base.list);
+	else
+		list_add_tail(&req->base.list, &req0->base.list);
+
+	list_for_each_entry_safe(req, n, &state->head, base.list) {
+		list_del_init(&req->base.list);
+
+		req->base.flags &= mask;
+		req->base.complete = ahash_reqchain_done;
+		req->base.data = state;
+		state->cur = req;
+		err = state->op(req);
+
+		if (err == -EINPROGRESS) {
+			if (!list_empty(&state->head))
+				err = -EBUSY;
+			goto out;
+		}
+
+		if (err == -EBUSY)
+			goto out;
+
+		req->base.err = err;
+		list_add_tail(&req->base.list, &req0->base.list);
+	}
+
+	ahash_restore_req(req0);
+
+out:
+	return err;
+}
+
+static void ahash_reqchain_done(void *data, int err)
+{
+	struct ahash_save_req_state *state = data;
+	crypto_completion_t compl = state->compl;
+
+	data = state->data;
+
+	if (err == -EINPROGRESS) {
+		if (!list_empty(&state->head))
+			return;
+		goto notify;
+	}
+
+	err = ahash_reqchain_finish(state, err, CRYPTO_TFM_REQ_MAY_BACKLOG);
+	if (err == -EBUSY)
+		return;
+
+notify:
+	compl(data, err);
+}
+
+static int ahash_do_req_chain(struct ahash_request *req,
+			      int (*op)(struct ahash_request *req))
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct ahash_save_req_state *state;
+	struct ahash_save_req_state state0;
+	int err;
+
+	if (!ahash_request_chained(req) || list_empty(&req->base.list) ||
+	    crypto_ahash_req_chain(tfm))
+		return op(req);
+
+	state = &state0;
+
+	if (ahash_is_async(tfm)) {
+		err = ahash_save_req(req, ahash_reqchain_done);
+		if (err) {
+			struct ahash_request *r2;
+
+			req->base.err = err;
+			list_for_each_entry(r2, &req->base.list, base.list)
+				r2->base.err = err;
+
+			return err;
+		}
+
+		state = req->base.data;
+	}
+
+	state->op = op;
+	state->cur = req;
+	INIT_LIST_HEAD(&state->head);
+	list_splice(&req->base.list, &state->head);
+
+	err = op(req);
+	if (err == -EBUSY || err == -EINPROGRESS)
+		return -EBUSY;
+
+	return ahash_reqchain_finish(state, err, ~0);
+}
+
 int crypto_ahash_init(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 
-	if (likely(tfm->using_shash))
-		return crypto_shash_init(prepare_shash_desc(req, tfm));
+	if (likely(tfm->using_shash)) {
+		struct ahash_request *r2;
+		int err;
+
+		err = crypto_shash_init(prepare_shash_desc(req, tfm));
+		req->base.err = err;
+		if (!ahash_request_chained(req))
+			return err;
+
+		list_for_each_entry(r2, &req->base.list, base.list) {
+			struct shash_desc *desc;
+
+			desc = prepare_shash_desc(r2, tfm);
+			r2->base.err = crypto_shash_init(desc);
+		}
+
+		return 0;
+	}
+
 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		return -ENOKEY;
-	return crypto_ahash_alg(tfm)->init(req);
+
+	return ahash_do_req_chain(req, crypto_ahash_alg(tfm)->init);
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_init);
 
 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
 {
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct ahash_save_req_state *state;
 	gfp_t gfp;
 	u32 flags;
 
+	if (!ahash_is_async(tfm))
+		return 0;
+
 	flags = ahash_request_flags(req);
 	gfp = (flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?  GFP_KERNEL : GFP_ATOMIC;
 	state = kmalloc(sizeof(*state), gfp);
@@ -284,14 +418,20 @@  static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
 	state->data = req->base.data;
 	req->base.complete = cplt;
 	req->base.data = state;
-	state->req = req;
+	state->req0 = req;
 
 	return 0;
 }
 
 static void ahash_restore_req(struct ahash_request *req)
 {
-	struct ahash_save_req_state *state = req->base.data;
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct ahash_save_req_state *state;
+
+	if (!ahash_is_async(tfm))
+		return;
+
+	state = req->base.data;
 
 	req->base.complete = state->compl;
 	req->base.data = state->data;
@@ -302,10 +442,26 @@  int crypto_ahash_update(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 
-	if (likely(tfm->using_shash))
-		return shash_ahash_update(req, ahash_request_ctx(req));
+	if (likely(tfm->using_shash)) {
+		struct ahash_request *r2;
+		int err;
 
-	return crypto_ahash_alg(tfm)->update(req);
+		err = shash_ahash_update(req, ahash_request_ctx(req));
+		req->base.err = err;
+		if (!ahash_request_chained(req))
+			return err;
+
+		list_for_each_entry(r2, &req->base.list, base.list) {
+			struct shash_desc *desc;
+
+			desc = ahash_request_ctx(r2);
+			r2->base.err = shash_ahash_update(r2, desc);
+		}
+
+		return 0;
+	}
+
+	return ahash_do_req_chain(req, crypto_ahash_alg(tfm)->update);
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_update);
 
@@ -313,10 +469,26 @@  int crypto_ahash_final(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 
-	if (likely(tfm->using_shash))
-		return crypto_shash_final(ahash_request_ctx(req), req->result);
+	if (likely(tfm->using_shash)) {
+		struct ahash_request *r2;
+		int err;
 
-	return crypto_ahash_alg(tfm)->final(req);
+		err = crypto_shash_final(ahash_request_ctx(req), req->result);
+		req->base.err = err;
+		if (!ahash_request_chained(req))
+			return err;
+
+		list_for_each_entry(r2, &req->base.list, base.list) {
+			struct shash_desc *desc;
+
+			desc = ahash_request_ctx(r2);
+			r2->base.err = crypto_shash_final(desc, r2->result);
+		}
+
+		return 0;
+	}
+
+	return ahash_do_req_chain(req, crypto_ahash_alg(tfm)->final);
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 
@@ -324,10 +496,29 @@  int crypto_ahash_finup(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 
-	if (likely(tfm->using_shash))
-		return shash_ahash_finup(req, ahash_request_ctx(req));
+	if (likely(tfm->using_shash)) {
+		struct ahash_request *r2;
+		int err;
 
-	return crypto_ahash_alg(tfm)->finup(req);
+		err = shash_ahash_finup(req, ahash_request_ctx(req));
+		req->base.err = err;
+		if (!ahash_request_chained(req))
+			return err;
+
+		list_for_each_entry(r2, &req->base.list, base.list) {
+			struct shash_desc *desc;
+
+			desc = ahash_request_ctx(r2);
+			r2->base.err = shash_ahash_finup(r2, desc);
+		}
+
+		return 0;
+	}
+
+	if (!crypto_ahash_alg(tfm)->finup)
+		return ahash_def_finup(req);
+
+	return ahash_do_req_chain(req, crypto_ahash_alg(tfm)->finup);
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 
@@ -335,20 +526,36 @@  int crypto_ahash_digest(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 
-	if (likely(tfm->using_shash))
-		return shash_ahash_digest(req, prepare_shash_desc(req, tfm));
+	if (likely(tfm->using_shash)) {
+		struct ahash_request *r2;
+		int err;
+
+		err = shash_ahash_digest(req, prepare_shash_desc(req, tfm));
+		req->base.err = err;
+		if (!ahash_request_chained(req))
+			return err;
+
+		list_for_each_entry(r2, &req->base.list, base.list) {
+			struct shash_desc *desc;
+
+			desc = prepare_shash_desc(r2, tfm);
+			r2->base.err = shash_ahash_digest(r2, desc);
+		}
+
+		return 0;
+	}
 
 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		return -ENOKEY;
 
-	return crypto_ahash_alg(tfm)->digest(req);
+	return ahash_do_req_chain(req, crypto_ahash_alg(tfm)->digest);
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 
 static void ahash_def_finup_done2(void *data, int err)
 {
 	struct ahash_save_req_state *state = data;
-	struct ahash_request *areq = state->req;
+	struct ahash_request *areq = state->req0;
 
 	if (err == -EINPROGRESS)
 		return;
@@ -359,12 +566,15 @@  static void ahash_def_finup_done2(void *data, int err)
 
 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
 {
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
 	if (err)
 		goto out;
 
-	req->base.complete = ahash_def_finup_done2;
+	if (ahash_is_async(tfm))
+		req->base.complete = ahash_def_finup_done2;
 
-	err = crypto_ahash_alg(crypto_ahash_reqtfm(req))->final(req);
+	err = crypto_ahash_final(req);
 	if (err == -EINPROGRESS || err == -EBUSY)
 		return err;
 
@@ -380,7 +590,7 @@  static void ahash_def_finup_done1(void *data, int err)
 	struct ahash_request *areq;
 
 	state = *state0;
-	areq = state.req;
+	areq = state.req0;
 	if (err == -EINPROGRESS)
 		goto out;
 
@@ -396,14 +606,13 @@  static void ahash_def_finup_done1(void *data, int err)
 
 static int ahash_def_finup(struct ahash_request *req)
 {
-	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	int err;
 
 	err = ahash_save_req(req, ahash_def_finup_done1);
 	if (err)
 		return err;
 
-	err = crypto_ahash_alg(tfm)->update(req);
+	err = crypto_ahash_update(req);
 	if (err == -EINPROGRESS || err == -EBUSY)
 		return err;
 
@@ -618,8 +827,6 @@  static int ahash_prepare_alg(struct ahash_alg *alg)
 	base->cra_type = &crypto_ahash_type;
 	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 
-	if (!alg->finup)
-		alg->finup = ahash_def_finup;
 	if (!alg->setkey)
 		alg->setkey = ahash_nosetkey;
 
diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index 156de41ca760..c5df380c7d08 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -271,4 +271,14 @@  static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 	return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 }
 
+static inline bool crypto_request_chained(struct crypto_async_request *req)
+{
+	return req->flags & CRYPTO_TFM_REQ_CHAIN;
+}
+
+static inline bool crypto_tfm_req_chain(struct crypto_tfm *tfm)
+{
+	return tfm->__crt_alg->cra_flags & CRYPTO_ALG_REQ_CHAIN;
+}
+
 #endif	/* _CRYPTO_ALGAPI_H */
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index 9c1f8ca59a77..de5e5dcd0c95 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -621,6 +621,7 @@  static inline void ahash_request_set_callback(struct ahash_request *req,
 {
 	req->base.complete = compl;
 	req->base.data = data;
+	flags &= ~CRYPTO_TFM_REQ_CHAIN;
 	req->base.flags = flags;
 }
 
@@ -646,6 +647,20 @@  static inline void ahash_request_set_crypt(struct ahash_request *req,
 	req->result = result;
 }
 
+static inline void ahash_reqchain_init(struct ahash_request *req,
+				       u32 flags, crypto_completion_t compl,
+				       void *data)
+{
+	ahash_request_set_callback(req, flags, compl, data);
+	crypto_reqchain_init(&req->base);
+}
+
+static inline void ahash_request_chain(struct ahash_request *req,
+				       struct ahash_request *head)
+{
+	crypto_request_chain(&req->base, &head->base);
+}
+
 /**
  * DOC: Synchronous Message Digest API
  *
@@ -947,4 +962,14 @@  static inline void shash_desc_zero(struct shash_desc *desc)
 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
 }
 
+static inline int ahash_request_err(struct ahash_request *req)
+{
+	return req->base.err;
+}
+
+static inline bool ahash_is_async(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_is_async(&tfm->base);
+}
+
 #endif	/* _CRYPTO_HASH_H */
diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index 58967593b6b4..81542a48587e 100644
--- a/include/crypto/internal/hash.h
+++ b/include/crypto/internal/hash.h
@@ -270,5 +270,15 @@  static inline struct crypto_shash *__crypto_shash_cast(struct crypto_tfm *tfm)
 	return container_of(tfm, struct crypto_shash, base);
 }
 
+static inline bool ahash_request_chained(struct ahash_request *req)
+{
+	return crypto_request_chained(&req->base);
+}
+
+static inline bool crypto_ahash_req_chain(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_req_chain(&tfm->base);
+}
+
 #endif	/* _CRYPTO_INTERNAL_HASH_H */
 
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index b164da5e129e..6126c57b8452 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -13,6 +13,8 @@ 
 #define _LINUX_CRYPTO_H
 
 #include <linux/completion.h>
+#include <linux/errno.h>
+#include <linux/list.h>
 #include <linux/refcount.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -124,6 +126,9 @@ 
  */
 #define CRYPTO_ALG_FIPS_INTERNAL	0x00020000
 
+/* Set if the algorithm supports request chains. */
+#define CRYPTO_ALG_REQ_CHAIN		0x00040000
+
 /*
  * Transform masks and values (for crt_flags).
  */
@@ -133,6 +138,7 @@ 
 #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS	0x00000100
 #define CRYPTO_TFM_REQ_MAY_SLEEP	0x00000200
 #define CRYPTO_TFM_REQ_MAY_BACKLOG	0x00000400
+#define CRYPTO_TFM_REQ_CHAIN		0x00000800
 
 /*
  * Miscellaneous stuff.
@@ -174,6 +180,7 @@  struct crypto_async_request {
 	struct crypto_tfm *tfm;
 
 	u32 flags;
+	int err;
 };
 
 /**
@@ -540,5 +547,24 @@  int crypto_comp_decompress(struct crypto_comp *tfm,
 			   const u8 *src, unsigned int slen,
 			   u8 *dst, unsigned int *dlen);
 
+static inline void crypto_reqchain_init(struct crypto_async_request *req)
+{
+	req->err = -EINPROGRESS;
+	req->flags |= CRYPTO_TFM_REQ_CHAIN;
+	INIT_LIST_HEAD(&req->list);
+}
+
+static inline void crypto_request_chain(struct crypto_async_request *req,
+					struct crypto_async_request *head)
+{
+	req->err = -EINPROGRESS;
+	list_add_tail(&req->list, &head->list);
+}
+
+static inline bool crypto_tfm_is_async(struct crypto_tfm *tfm)
+{
+	return tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC;
+}
+
 #endif	/* _LINUX_CRYPTO_H */