[PATCH v3 04/16] crypto: riscv/sha512 - Stop depending on sha512_generic_block_fn

[Eric Biggers <ebiggers@kernel.org>]

sha512_generic_block_fn() will no longer be available when the SHA-512
support in the old-school crypto API is changed to just wrap the SHA-512
library.  Replace the use of sha512_generic_block_fn() in
sha512-riscv64-glue.c with temporary code that uses the library's
__sha512_update().  This is just a temporary workaround to keep the
kernel building and functional at each commit; this code gets superseded
when the RISC-V optimized SHA-512 is migrated to lib/crypto/ anyway.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 arch/riscv/crypto/Kconfig               | 1 +
 arch/riscv/crypto/sha512-riscv64-glue.c | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/crypto/Kconfig b/arch/riscv/crypto/Kconfig
index cd9b776602f89..53e4e1eacf554 100644
--- a/arch/riscv/crypto/Kconfig
+++ b/arch/riscv/crypto/Kconfig
@@ -29,10 +29,11 @@ config CRYPTO_GHASH_RISCV64
 	  - Zvkg vector crypto extension
 
 config CRYPTO_SHA512_RISCV64
 	tristate "Hash functions: SHA-384 and SHA-512"
 	depends on 64BIT && RISCV_ISA_V && TOOLCHAIN_HAS_VECTOR_CRYPTO
+	select CRYPTO_LIB_SHA512
 	select CRYPTO_SHA512
 	help
 	  SHA-384 and SHA-512 secure hash algorithm (FIPS 180)
 
 	  Architecture: riscv64 using:
diff --git a/arch/riscv/crypto/sha512-riscv64-glue.c b/arch/riscv/crypto/sha512-riscv64-glue.c
index 4634fca78ae24..b3dbc71de07b0 100644
--- a/arch/riscv/crypto/sha512-riscv64-glue.c
+++ b/arch/riscv/crypto/sha512-riscv64-glue.c
@@ -36,11 +36,17 @@ static void sha512_block(struct sha512_state *state, const u8 *data,
 	if (crypto_simd_usable()) {
 		kernel_vector_begin();
 		sha512_transform_zvknhb_zvkb(state, data, num_blocks);
 		kernel_vector_end();
 	} else {
-		sha512_generic_block_fn(state, data, num_blocks);
+		struct __sha512_ctx ctx = {};
+
+		static_assert(sizeof(ctx.state) == sizeof(state->state));
+		memcpy(&ctx.state, state->state, sizeof(ctx.state));
+		__sha512_update(&ctx, data,
+				(size_t)num_blocks * SHA512_BLOCK_SIZE);
+		memcpy(state->state, &ctx.state, sizeof(state->state));
 	}
 }
 
 static int riscv64_sha512_update(struct shash_desc *desc, const u8 *data,
 				 unsigned int len)
-- 
2.50.0