crypto: skcipher - remove the "blkcipher" algorithm type

Now that all "blkcipher" algorithms have been converted to "skcipher",
remove the blkcipher algorithm type.

The skcipher (symmetric key cipher) algorithm type was introduced a few
years ago to replace both blkcipher and ablkcipher (synchronous and
asynchronous block cipher).  The advantages of skcipher include:

  - A much less confusing name, since none of these algorithm types have
    ever actually been for raw block ciphers, but rather for all
    length-preserving encryption modes including block cipher modes of
    operation, stream ciphers, and other length-preserving modes.

  - It unified blkcipher and ablkcipher into a single algorithm type
    which supports both synchronous and asynchronous implementations.
    Note, blkcipher already operated only on scatterlists, so the fact
    that skcipher does too isn't a regression in functionality.

  - Better type safety by using struct skcipher_alg, struct
    crypto_skcipher, etc. instead of crypto_alg, crypto_tfm, etc.

  - It sometimes simplifies the implementations of algorithms.

Also, the blkcipher API was no longer being tested.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Documentation/crypto/api-skcipher.rst

@@ -5,7 +5,7 @@ Block Cipher Algorithm Definitions
    :doc: Block Cipher Algorithm Definitions
 
 .. kernel-doc:: include/linux/crypto.h
-   :functions: crypto_alg ablkcipher_alg blkcipher_alg cipher_alg compress_alg
+   :functions: crypto_alg ablkcipher_alg cipher_alg compress_alg
 
 Symmetric Key Cipher API
 ------------------------
@@ -51,12 +51,3 @@ Asynchronous Cipher Request Handle - Deprecated
 
 .. kernel-doc:: include/linux/crypto.h
    :functions: crypto_ablkcipher_reqsize ablkcipher_request_set_tfm ablkcipher_request_alloc ablkcipher_request_free ablkcipher_request_set_callback ablkcipher_request_set_crypt
-
-Synchronous Block Cipher API - Deprecated
------------------------------------------
-
-.. kernel-doc:: include/linux/crypto.h
-   :doc: Synchronous Block Cipher API
-
-.. kernel-doc:: include/linux/crypto.h
-   :functions: crypto_alloc_blkcipher crypto_free_blkcipher crypto_has_blkcipher crypto_blkcipher_name crypto_blkcipher_ivsize crypto_blkcipher_blocksize crypto_blkcipher_setkey crypto_blkcipher_encrypt crypto_blkcipher_encrypt_iv crypto_blkcipher_decrypt crypto_blkcipher_decrypt_iv crypto_blkcipher_set_iv crypto_blkcipher_get_iv

Documentation/crypto/architecture.rst

@@ -201,8 +201,6 @@ the aforementioned cipher types:
 -  CRYPTO_ALG_TYPE_AEAD Authenticated Encryption with Associated Data
    (MAC)
 
--  CRYPTO_ALG_TYPE_BLKCIPHER Synchronous multi-block cipher
-
 -  CRYPTO_ALG_TYPE_ABLKCIPHER Asynchronous multi-block cipher
 
 -  CRYPTO_ALG_TYPE_KPP Key-agreement Protocol Primitive (KPP) such as

Documentation/crypto/devel-algos.rst

@@ -128,25 +128,20 @@ process requests that are unaligned. This implies, however, additional
 overhead as the kernel crypto API needs to perform the realignment of
 the data which may imply moving of data.
 
-Cipher Definition With struct blkcipher_alg and ablkcipher_alg
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Cipher Definition With struct skcipher_alg
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Struct blkcipher_alg defines a synchronous block cipher whereas struct
-ablkcipher_alg defines an asynchronous block cipher.
+Struct skcipher_alg defines a multi-block cipher, or more generally, a
+length-preserving symmetric cipher algorithm.
 
-Please refer to the single block cipher description for schematics of
-the block cipher usage.
+Scatterlist handling
+~~~~~~~~~~~~~~~~~~~~
 
-Specifics Of Asynchronous Multi-Block Cipher
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-There are a couple of specifics to the asynchronous interface.
-
-First of all, some of the drivers will want to use the Generic
-ScatterWalk in case the hardware needs to be fed separate chunks of the
-scatterlist which contains the plaintext and will contain the
-ciphertext. Please refer to the ScatterWalk interface offered by the
-Linux kernel scatter / gather list implementation.
+Some drivers will want to use the Generic ScatterWalk in case the
+hardware needs to be fed separate chunks of the scatterlist which
+contains the plaintext and will contain the ciphertext. Please refer
+to the ScatterWalk interface offered by the Linux kernel scatter /
+gather list implementation.
 
 Hashing [HASH]
 --------------