From: Eric Biggers <ebigg...@google.com>

Instead of providing crypto_shash algorithms for the arch-optimized
SHA-256 code, instead implement the SHA-256 library.  This is much
simpler, it makes the SHA-256 library functions be arch-optimized, and
it fixes the longstanding issue where the arch-optimized SHA-256 was
disabled by default.  SHA-256 still remains available through
crypto_shash, but individual architectures no longer need to handle it.

Remove support for SHA-256 finalization from the ARMv8 CE assembly code,
since the library does not yet support architecture-specific overrides
of the finalization.  (Support for that has been omitted for now, for
simplicity and because usually it isn't performance-critical.)

To match sha256_blocks_arch(), change the type of the nblocks parameter
of the assembly functions from int or 'unsigned int' to size_t.  Update
the ARMv8 CE assembly function accordingly.  The scalar and NEON
assembly functions actually already treated it as size_t.

While renaming the assembly files, also fix the naming quirks where
"sha2" meant sha256, and "sha512" meant both sha256 and sha512.

Signed-off-by: Eric Biggers <ebigg...@google.com>
---
 arch/arm64/configs/defconfig                  |   1 -
 arch/arm64/crypto/Kconfig                     |  19 ---
 arch/arm64/crypto/Makefile                    |  13 +-
 arch/arm64/crypto/sha2-ce-glue.c              | 138 ----------------
 arch/arm64/crypto/sha256-glue.c               | 156 ------------------
 arch/arm64/lib/crypto/.gitignore              |   1 +
 arch/arm64/lib/crypto/Kconfig                 |   5 +
 arch/arm64/lib/crypto/Makefile                |   9 +-
 .../crypto/sha2-armv8.pl}                     |   0
 .../sha2-ce-core.S => lib/crypto/sha256-ce.S} |  36 +---
 arch/arm64/lib/crypto/sha256.c                |  75 +++++++++
 11 files changed, 98 insertions(+), 355 deletions(-)
 delete mode 100644 arch/arm64/crypto/sha2-ce-glue.c
 delete mode 100644 arch/arm64/crypto/sha256-glue.c
 rename arch/arm64/{crypto/sha512-armv8.pl => lib/crypto/sha2-armv8.pl} (100%)
 rename arch/arm64/{crypto/sha2-ce-core.S => lib/crypto/sha256-ce.S} (80%)
 create mode 100644 arch/arm64/lib/crypto/sha256.c

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 5bb8f09422a22..b0d4c7d173ea7 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -1735,11 +1735,10 @@ CONFIG_CRYPTO_MICHAEL_MIC=m
 CONFIG_CRYPTO_ANSI_CPRNG=y
 CONFIG_CRYPTO_USER_API_RNG=m
 CONFIG_CRYPTO_CHACHA20_NEON=m
 CONFIG_CRYPTO_GHASH_ARM64_CE=y
 CONFIG_CRYPTO_SHA1_ARM64_CE=y
-CONFIG_CRYPTO_SHA2_ARM64_CE=y
 CONFIG_CRYPTO_SHA512_ARM64_CE=m
 CONFIG_CRYPTO_SHA3_ARM64=m
 CONFIG_CRYPTO_SM3_ARM64_CE=m
 CONFIG_CRYPTO_AES_ARM64_CE_BLK=y
 CONFIG_CRYPTO_AES_ARM64_BS=m
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 55a7d87a67690..c44b0f202a1f5 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -34,29 +34,10 @@ config CRYPTO_SHA1_ARM64_CE
          SHA-1 secure hash algorithm (FIPS 180)
 
          Architecture: arm64 using:
          - ARMv8 Crypto Extensions
 
-config CRYPTO_SHA256_ARM64
-       tristate "Hash functions: SHA-224 and SHA-256"
-       select CRYPTO_HASH
-       help
-         SHA-224 and SHA-256 secure hash algorithms (FIPS 180)
-
-         Architecture: arm64
-
-config CRYPTO_SHA2_ARM64_CE
-       tristate "Hash functions: SHA-224 and SHA-256 (ARMv8 Crypto Extensions)"
-       depends on KERNEL_MODE_NEON
-       select CRYPTO_HASH
-       select CRYPTO_SHA256_ARM64
-       help
-         SHA-224 and SHA-256 secure hash algorithms (FIPS 180)
-
-         Architecture: arm64 using:
-         - ARMv8 Crypto Extensions
-
 config CRYPTO_SHA512_ARM64
        tristate "Hash functions: SHA-384 and SHA-512"
        select CRYPTO_HASH
        help
          SHA-384 and SHA-512 secure hash algorithms (FIPS 180)
diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
index 089ae3ddde810..c231c980c5142 100644
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -6,13 +6,10 @@
 #
 
 obj-$(CONFIG_CRYPTO_SHA1_ARM64_CE) += sha1-ce.o
 sha1-ce-y := sha1-ce-glue.o sha1-ce-core.o
 
-obj-$(CONFIG_CRYPTO_SHA2_ARM64_CE) += sha2-ce.o
-sha2-ce-y := sha2-ce-glue.o sha2-ce-core.o
-
 obj-$(CONFIG_CRYPTO_SHA512_ARM64_CE) += sha512-ce.o
 sha512-ce-y := sha512-ce-glue.o sha512-ce-core.o
 
 obj-$(CONFIG_CRYPTO_SHA3_ARM64) += sha3-ce.o
 sha3-ce-y := sha3-ce-glue.o sha3-ce-core.o
@@ -54,13 +51,10 @@ obj-$(CONFIG_CRYPTO_AES_ARM64_CE_BLK) += aes-ce-blk.o
 aes-ce-blk-y := aes-glue-ce.o aes-ce.o
 
 obj-$(CONFIG_CRYPTO_AES_ARM64_NEON_BLK) += aes-neon-blk.o
 aes-neon-blk-y := aes-glue-neon.o aes-neon.o
 
-obj-$(CONFIG_CRYPTO_SHA256_ARM64) += sha256-arm64.o
-sha256-arm64-y := sha256-glue.o sha256-core.o
-
 obj-$(CONFIG_CRYPTO_SHA512_ARM64) += sha512-arm64.o
 sha512-arm64-y := sha512-glue.o sha512-core.o
 
 obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
 nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o
@@ -72,12 +66,9 @@ obj-$(CONFIG_CRYPTO_AES_ARM64_BS) += aes-neon-bs.o
 aes-neon-bs-y := aes-neonbs-core.o aes-neonbs-glue.o
 
 quiet_cmd_perlasm = PERLASM $@
       cmd_perlasm = $(PERL) $(<) void $(@)
 
-$(obj)/%-core.S: $(src)/%-armv8.pl
-       $(call cmd,perlasm)
-
-$(obj)/sha256-core.S: $(src)/sha512-armv8.pl
+$(obj)/sha512-core.S: $(src)/../lib/crypto/sha2-armv8.pl
        $(call cmd,perlasm)
 
-clean-files += sha256-core.S sha512-core.S
+clean-files += sha512-core.S
diff --git a/arch/arm64/crypto/sha2-ce-glue.c b/arch/arm64/crypto/sha2-ce-glue.c
deleted file mode 100644
index 912c215101eb1..0000000000000
--- a/arch/arm64/crypto/sha2-ce-glue.c
+++ /dev/null
@@ -1,138 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * sha2-ce-glue.c - SHA-224/SHA-256 using ARMv8 Crypto Extensions
- *
- * Copyright (C) 2014 - 2017 Linaro Ltd <ard.biesheu...@linaro.org>
- */
-
-#include <asm/neon.h>
-#include <crypto/internal/hash.h>
-#include <crypto/sha2.h>
-#include <crypto/sha256_base.h>
-#include <linux/cpufeature.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/string.h>
-
-MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto 
Extensions");
-MODULE_AUTHOR("Ard Biesheuvel <ard.biesheu...@linaro.org>");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS_CRYPTO("sha224");
-MODULE_ALIAS_CRYPTO("sha256");
-
-struct sha256_ce_state {
-       struct crypto_sha256_state sst;
-       u32                     finalize;
-};
-
-extern const u32 sha256_ce_offsetof_count;
-extern const u32 sha256_ce_offsetof_finalize;
-
-asmlinkage int __sha256_ce_transform(struct sha256_ce_state *sst, u8 const 
*src,
-                                    int blocks);
-
-static void sha256_ce_transform(struct crypto_sha256_state *sst, u8 const *src,
-                               int blocks)
-{
-       while (blocks) {
-               int rem;
-
-               kernel_neon_begin();
-               rem = __sha256_ce_transform(container_of(sst,
-                                                        struct sha256_ce_state,
-                                                        sst), src, blocks);
-               kernel_neon_end();
-               src += (blocks - rem) * SHA256_BLOCK_SIZE;
-               blocks = rem;
-       }
-}
-
-const u32 sha256_ce_offsetof_count = offsetof(struct sha256_ce_state,
-                                             sst.count);
-const u32 sha256_ce_offsetof_finalize = offsetof(struct sha256_ce_state,
-                                                finalize);
-
-static int sha256_ce_update(struct shash_desc *desc, const u8 *data,
-                           unsigned int len)
-{
-       struct sha256_ce_state *sctx = shash_desc_ctx(desc);
-
-       sctx->finalize = 0;
-       return sha256_base_do_update_blocks(desc, data, len,
-                                           sha256_ce_transform);
-}
-
-static int sha256_ce_finup(struct shash_desc *desc, const u8 *data,
-                          unsigned int len, u8 *out)
-{
-       struct sha256_ce_state *sctx = shash_desc_ctx(desc);
-       bool finalize = !(len % SHA256_BLOCK_SIZE) && len;
-
-       /*
-        * Allow the asm code to perform the finalization if there is no
-        * partial data and the input is a round multiple of the block size.
-        */
-       sctx->finalize = finalize;
-
-       if (finalize)
-               sha256_base_do_update_blocks(desc, data, len,
-                                            sha256_ce_transform);
-       else
-               sha256_base_do_finup(desc, data, len, sha256_ce_transform);
-       return sha256_base_finish(desc, out);
-}
-
-static int sha256_ce_digest(struct shash_desc *desc, const u8 *data,
-                           unsigned int len, u8 *out)
-{
-       sha256_base_init(desc);
-       return sha256_ce_finup(desc, data, len, out);
-}
-
-static struct shash_alg algs[] = { {
-       .init                   = sha224_base_init,
-       .update                 = sha256_ce_update,
-       .finup                  = sha256_ce_finup,
-       .descsize               = sizeof(struct sha256_ce_state),
-       .statesize              = sizeof(struct crypto_sha256_state),
-       .digestsize             = SHA224_DIGEST_SIZE,
-       .base                   = {
-               .cra_name               = "sha224",
-               .cra_driver_name        = "sha224-ce",
-               .cra_priority           = 200,
-               .cra_flags              = CRYPTO_AHASH_ALG_BLOCK_ONLY |
-                                         CRYPTO_AHASH_ALG_FINUP_MAX,
-               .cra_blocksize          = SHA256_BLOCK_SIZE,
-               .cra_module             = THIS_MODULE,
-       }
-}, {
-       .init                   = sha256_base_init,
-       .update                 = sha256_ce_update,
-       .finup                  = sha256_ce_finup,
-       .digest                 = sha256_ce_digest,
-       .descsize               = sizeof(struct sha256_ce_state),
-       .statesize              = sizeof(struct crypto_sha256_state),
-       .digestsize             = SHA256_DIGEST_SIZE,
-       .base                   = {
-               .cra_name               = "sha256",
-               .cra_driver_name        = "sha256-ce",
-               .cra_priority           = 200,
-               .cra_flags              = CRYPTO_AHASH_ALG_BLOCK_ONLY |
-                                         CRYPTO_AHASH_ALG_FINUP_MAX,
-               .cra_blocksize          = SHA256_BLOCK_SIZE,
-               .cra_module             = THIS_MODULE,
-       }
-} };
-
-static int __init sha2_ce_mod_init(void)
-{
-       return crypto_register_shashes(algs, ARRAY_SIZE(algs));
-}
-
-static void __exit sha2_ce_mod_fini(void)
-{
-       crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
-}
-
-module_cpu_feature_match(SHA2, sha2_ce_mod_init);
-module_exit(sha2_ce_mod_fini);
diff --git a/arch/arm64/crypto/sha256-glue.c b/arch/arm64/crypto/sha256-glue.c
deleted file mode 100644
index d63ea82e1374e..0000000000000
--- a/arch/arm64/crypto/sha256-glue.c
+++ /dev/null
@@ -1,156 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Linux/arm64 port of the OpenSSL SHA256 implementation for AArch64
- *
- * Copyright (c) 2016 Linaro Ltd. <ard.biesheu...@linaro.org>
- */
-
-#include <asm/neon.h>
-#include <crypto/internal/hash.h>
-#include <crypto/sha2.h>
-#include <crypto/sha256_base.h>
-#include <linux/cpufeature.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-
-MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash for arm64");
-MODULE_AUTHOR("Andy Polyakov <ap...@openssl.org>");
-MODULE_AUTHOR("Ard Biesheuvel <ard.biesheu...@linaro.org>");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS_CRYPTO("sha224");
-MODULE_ALIAS_CRYPTO("sha256");
-
-asmlinkage void sha256_block_data_order(u32 *digest, const void *data,
-                                       unsigned int num_blks);
-EXPORT_SYMBOL(sha256_block_data_order);
-
-static void sha256_arm64_transform(struct crypto_sha256_state *sst,
-                                  u8 const *src, int blocks)
-{
-       sha256_block_data_order(sst->state, src, blocks);
-}
-
-asmlinkage void sha256_block_neon(u32 *digest, const void *data,
-                                 unsigned int num_blks);
-
-static void sha256_neon_transform(struct crypto_sha256_state *sst,
-                                 u8 const *src, int blocks)
-{
-       kernel_neon_begin();
-       sha256_block_neon(sst->state, src, blocks);
-       kernel_neon_end();
-}
-
-static int crypto_sha256_arm64_update(struct shash_desc *desc, const u8 *data,
-                                     unsigned int len)
-{
-       return sha256_base_do_update_blocks(desc, data, len,
-                                           sha256_arm64_transform);
-}
-
-static int crypto_sha256_arm64_finup(struct shash_desc *desc, const u8 *data,
-                                    unsigned int len, u8 *out)
-{
-       sha256_base_do_finup(desc, data, len, sha256_arm64_transform);
-       return sha256_base_finish(desc, out);
-}
-
-static struct shash_alg algs[] = { {
-       .digestsize             = SHA256_DIGEST_SIZE,
-       .init                   = sha256_base_init,
-       .update                 = crypto_sha256_arm64_update,
-       .finup                  = crypto_sha256_arm64_finup,
-       .descsize               = sizeof(struct crypto_sha256_state),
-       .base.cra_name          = "sha256",
-       .base.cra_driver_name   = "sha256-arm64",
-       .base.cra_priority      = 125,
-       .base.cra_flags         = CRYPTO_AHASH_ALG_BLOCK_ONLY |
-                                 CRYPTO_AHASH_ALG_FINUP_MAX,
-       .base.cra_blocksize     = SHA256_BLOCK_SIZE,
-       .base.cra_module        = THIS_MODULE,
-}, {
-       .digestsize             = SHA224_DIGEST_SIZE,
-       .init                   = sha224_base_init,
-       .update                 = crypto_sha256_arm64_update,
-       .finup                  = crypto_sha256_arm64_finup,
-       .descsize               = sizeof(struct crypto_sha256_state),
-       .base.cra_name          = "sha224",
-       .base.cra_driver_name   = "sha224-arm64",
-       .base.cra_priority      = 125,
-       .base.cra_flags         = CRYPTO_AHASH_ALG_BLOCK_ONLY |
-                                 CRYPTO_AHASH_ALG_FINUP_MAX,
-       .base.cra_blocksize     = SHA224_BLOCK_SIZE,
-       .base.cra_module        = THIS_MODULE,
-} };
-
-static int sha256_update_neon(struct shash_desc *desc, const u8 *data,
-                             unsigned int len)
-{
-       return sha256_base_do_update_blocks(desc, data, len,
-                                           sha256_neon_transform);
-}
-
-static int sha256_finup_neon(struct shash_desc *desc, const u8 *data,
-                            unsigned int len, u8 *out)
-{
-       if (len >= SHA256_BLOCK_SIZE) {
-               int remain = sha256_update_neon(desc, data, len);
-
-               data += len - remain;
-               len = remain;
-       }
-       sha256_base_do_finup(desc, data, len, sha256_neon_transform);
-       return sha256_base_finish(desc, out);
-}
-
-static struct shash_alg neon_algs[] = { {
-       .digestsize             = SHA256_DIGEST_SIZE,
-       .init                   = sha256_base_init,
-       .update                 = sha256_update_neon,
-       .finup                  = sha256_finup_neon,
-       .descsize               = sizeof(struct crypto_sha256_state),
-       .base.cra_name          = "sha256",
-       .base.cra_driver_name   = "sha256-arm64-neon",
-       .base.cra_priority      = 150,
-       .base.cra_flags         = CRYPTO_AHASH_ALG_BLOCK_ONLY |
-                                 CRYPTO_AHASH_ALG_FINUP_MAX,
-       .base.cra_blocksize     = SHA256_BLOCK_SIZE,
-       .base.cra_module        = THIS_MODULE,
-}, {
-       .digestsize             = SHA224_DIGEST_SIZE,
-       .init                   = sha224_base_init,
-       .update                 = sha256_update_neon,
-       .finup                  = sha256_finup_neon,
-       .descsize               = sizeof(struct crypto_sha256_state),
-       .base.cra_name          = "sha224",
-       .base.cra_driver_name   = "sha224-arm64-neon",
-       .base.cra_priority      = 150,
-       .base.cra_flags         = CRYPTO_AHASH_ALG_BLOCK_ONLY |
-                                 CRYPTO_AHASH_ALG_FINUP_MAX,
-       .base.cra_blocksize     = SHA224_BLOCK_SIZE,
-       .base.cra_module        = THIS_MODULE,
-} };
-
-static int __init sha256_mod_init(void)
-{
-       int ret = crypto_register_shashes(algs, ARRAY_SIZE(algs));
-       if (ret)
-               return ret;
-
-       if (cpu_have_named_feature(ASIMD)) {
-               ret = crypto_register_shashes(neon_algs, ARRAY_SIZE(neon_algs));
-               if (ret)
-                       crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
-       }
-       return ret;
-}
-
-static void __exit sha256_mod_fini(void)
-{
-       if (cpu_have_named_feature(ASIMD))
-               crypto_unregister_shashes(neon_algs, ARRAY_SIZE(neon_algs));
-       crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
-}
-
-module_init(sha256_mod_init);
-module_exit(sha256_mod_fini);
diff --git a/arch/arm64/lib/crypto/.gitignore b/arch/arm64/lib/crypto/.gitignore
index 0d47d4f21c6de..12d74d8b03d0a 100644
--- a/arch/arm64/lib/crypto/.gitignore
+++ b/arch/arm64/lib/crypto/.gitignore
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 poly1305-core.S
+sha256-core.S
diff --git a/arch/arm64/lib/crypto/Kconfig b/arch/arm64/lib/crypto/Kconfig
index 0b903ef524d85..49e57bfdb5b52 100644
--- a/arch/arm64/lib/crypto/Kconfig
+++ b/arch/arm64/lib/crypto/Kconfig
@@ -10,5 +10,10 @@ config CRYPTO_CHACHA20_NEON
 config CRYPTO_POLY1305_NEON
        tristate
        depends on KERNEL_MODE_NEON
        default CRYPTO_LIB_POLY1305
        select CRYPTO_ARCH_HAVE_LIB_POLY1305
+
+config CRYPTO_SHA256_ARM64
+       tristate
+       default CRYPTO_LIB_SHA256
+       select CRYPTO_ARCH_HAVE_LIB_SHA256
diff --git a/arch/arm64/lib/crypto/Makefile b/arch/arm64/lib/crypto/Makefile
index ac624c3effdaf..141efe07155c0 100644
--- a/arch/arm64/lib/crypto/Makefile
+++ b/arch/arm64/lib/crypto/Makefile
@@ -5,12 +5,19 @@ chacha-neon-y := chacha-neon-core.o chacha-neon-glue.o
 
 obj-$(CONFIG_CRYPTO_POLY1305_NEON) += poly1305-neon.o
 poly1305-neon-y := poly1305-core.o poly1305-glue.o
 AFLAGS_poly1305-core.o += -Dpoly1305_init=poly1305_init_arm64
 
+obj-$(CONFIG_CRYPTO_SHA256_ARM64) += sha256-arm64.o
+sha256-arm64-y := sha256.o sha256-core.o
+sha256-arm64-$(CONFIG_KERNEL_MODE_NEON) += sha256-ce.o
+
 quiet_cmd_perlasm = PERLASM $@
       cmd_perlasm = $(PERL) $(<) void $(@)
 
 $(obj)/%-core.S: $(src)/%-armv8.pl
        $(call cmd,perlasm)
 
-clean-files += poly1305-core.S
+$(obj)/sha256-core.S: $(src)/sha2-armv8.pl
+       $(call cmd,perlasm)
+
+clean-files += poly1305-core.S sha256-core.S
diff --git a/arch/arm64/crypto/sha512-armv8.pl 
b/arch/arm64/lib/crypto/sha2-armv8.pl
similarity index 100%
rename from arch/arm64/crypto/sha512-armv8.pl
rename to arch/arm64/lib/crypto/sha2-armv8.pl
diff --git a/arch/arm64/crypto/sha2-ce-core.S 
b/arch/arm64/lib/crypto/sha256-ce.S
similarity index 80%
rename from arch/arm64/crypto/sha2-ce-core.S
rename to arch/arm64/lib/crypto/sha256-ce.S
index fce84d88ddb2c..a8461d6dad634 100644
--- a/arch/arm64/crypto/sha2-ce-core.S
+++ b/arch/arm64/lib/crypto/sha256-ce.S
@@ -69,12 +69,12 @@
        .word           0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3
        .word           0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208
        .word           0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 
        /*
-        * int __sha256_ce_transform(struct sha256_ce_state *sst, u8 const *src,
-        *                           int blocks)
+        * size_t __sha256_ce_transform(u32 state[SHA256_STATE_WORDS],
+        *                              const u8 *data, size_t nblocks);
         */
        .text
 SYM_FUNC_START(__sha256_ce_transform)
        /* load round constants */
        adr_l           x8, .Lsha2_rcon
@@ -84,24 +84,20 @@ SYM_FUNC_START(__sha256_ce_transform)
        ld1             {v12.4s-v15.4s}, [x8]
 
        /* load state */
        ld1             {dgav.4s, dgbv.4s}, [x0]
 
-       /* load sha256_ce_state::finalize */
-       ldr_l           w4, sha256_ce_offsetof_finalize, x4
-       ldr             w4, [x0, x4]
-
        /* load input */
 0:     ld1             {v16.4s-v19.4s}, [x1], #64
-       sub             w2, w2, #1
+       sub             x2, x2, #1
 
 CPU_LE(        rev32           v16.16b, v16.16b        )
 CPU_LE(        rev32           v17.16b, v17.16b        )
 CPU_LE(        rev32           v18.16b, v18.16b        )
 CPU_LE(        rev32           v19.16b, v19.16b        )
 
-1:     add             t0.4s, v16.4s, v0.4s
+       add             t0.4s, v16.4s, v0.4s
        mov             dg0v.16b, dgav.16b
        mov             dg1v.16b, dgbv.16b
 
        add_update      0,  v1, 16, 17, 18, 19
        add_update      1,  v2, 17, 18, 19, 16
@@ -126,32 +122,14 @@ CPU_LE(   rev32           v19.16b, v19.16b        )
        /* update state */
        add             dgav.4s, dgav.4s, dg0v.4s
        add             dgbv.4s, dgbv.4s, dg1v.4s
 
        /* handled all input blocks? */
-       cbz             w2, 2f
+       cbz             x2, 1f
        cond_yield      3f, x5, x6
        b               0b
 
-       /*
-        * Final block: add padding and total bit count.
-        * Skip if the input size was not a round multiple of the block size,
-        * the padding is handled by the C code in that case.
-        */
-2:     cbz             x4, 3f
-       ldr_l           w4, sha256_ce_offsetof_count, x4
-       ldr             x4, [x0, x4]
-       movi            v17.2d, #0
-       mov             x8, #0x80000000
-       movi            v18.2d, #0
-       ror             x7, x4, #29             // ror(lsl(x4, 3), 32)
-       fmov            d16, x8
-       mov             x4, #0
-       mov             v19.d[0], xzr
-       mov             v19.d[1], x7
-       b               1b
-
        /* store new state */
-3:     st1             {dgav.4s, dgbv.4s}, [x0]
-       mov             w0, w2
+1:     st1             {dgav.4s, dgbv.4s}, [x0]
+       mov             x0, x2
        ret
 SYM_FUNC_END(__sha256_ce_transform)
diff --git a/arch/arm64/lib/crypto/sha256.c b/arch/arm64/lib/crypto/sha256.c
new file mode 100644
index 0000000000000..2bd413c586d27
--- /dev/null
+++ b/arch/arm64/lib/crypto/sha256.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SHA-256 optimized for ARM64
+ *
+ * Copyright 2025 Google LLC
+ */
+#include <asm/neon.h>
+#include <crypto/internal/sha2.h>
+#include <crypto/internal/simd.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+asmlinkage void sha256_block_data_order(u32 state[SHA256_STATE_WORDS],
+                                       const u8 *data, size_t nblocks);
+asmlinkage void sha256_block_neon(u32 state[SHA256_STATE_WORDS],
+                                 const u8 *data, size_t nblocks);
+asmlinkage size_t __sha256_ce_transform(u32 state[SHA256_STATE_WORDS],
+                                       const u8 *data, size_t nblocks);
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);
+
+void sha256_blocks_arch(u32 state[SHA256_STATE_WORDS],
+                       const u8 *data, size_t nblocks)
+{
+       if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
+           static_branch_likely(&have_neon) && crypto_simd_usable()) {
+               if (static_branch_likely(&have_ce)) {
+                       do {
+                               size_t rem;
+
+                               kernel_neon_begin();
+                               rem = __sha256_ce_transform(state,
+                                                           data, nblocks);
+                               kernel_neon_end();
+                               data += (nblocks - rem) * SHA256_BLOCK_SIZE;
+                               nblocks = rem;
+                       } while (nblocks);
+               } else {
+                       kernel_neon_begin();
+                       sha256_block_neon(state, data, nblocks);
+                       kernel_neon_end();
+               }
+       } else {
+               sha256_block_data_order(state, data, nblocks);
+       }
+}
+EXPORT_SYMBOL(sha256_blocks_arch);
+
+bool sha256_is_arch_optimized(void)
+{
+       /* We always can use at least the ARM64 scalar implementation. */
+       return true;
+}
+EXPORT_SYMBOL(sha256_is_arch_optimized);
+
+static int __init sha256_arm64_mod_init(void)
+{
+       if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
+           cpu_have_named_feature(ASIMD)) {
+               static_branch_enable(&have_neon);
+               if (cpu_have_named_feature(SHA2))
+                       static_branch_enable(&have_ce);
+       }
+       return 0;
+}
+arch_initcall(sha256_arm64_mod_init);
+
+static void __exit sha256_arm64_mod_exit(void)
+{
+}
+module_exit(sha256_arm64_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA-256 optimized for ARM64");
-- 
2.49.0


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