From: Eric Biggers <ebiggers@xxxxxxxxxx> Since CBC decryption is parallelizable, make the RISC-V implementation of AES-CBC decryption process multiple blocks at a time, instead of processing the blocks one by one. This should improve performance. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- arch/riscv/crypto/aes-riscv64-zvkned.S | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/arch/riscv/crypto/aes-riscv64-zvkned.S b/arch/riscv/crypto/aes-riscv64-zvkned.S index 78d4e1186c074..43541aad6386c 100644 --- a/arch/riscv/crypto/aes-riscv64-zvkned.S +++ b/arch/riscv/crypto/aes-riscv64-zvkned.S @@ -132,33 +132,39 @@ SYM_FUNC_END(aes_ecb_decrypt_zvkned) addi INP, INP, 16 addi OUTP, OUTP, 16 addi LEN, LEN, -16 bnez LEN, 1b vse32.v v16, (IVP) // Store next IV ret .endm .macro aes_cbc_decrypt keylen + srli LEN, LEN, 2 // Convert LEN from bytes to words vle32.v v16, (IVP) // Load IV 1: - vle32.v v17, (INP) // Load ciphertext block - vmv.v.v v18, v17 // Save ciphertext block - aes_decrypt v17, \keylen // Decrypt - vxor.vv v17, v17, v16 // XOR with IV or prev ciphertext block - vse32.v v17, (OUTP) // Store plaintext block - vmv.v.v v16, v18 // Next "IV" is prev ciphertext block - addi INP, INP, 16 - addi OUTP, OUTP, 16 - addi LEN, LEN, -16 + vsetvli t0, LEN, e32, m4, ta, ma + vle32.v v20, (INP) // Load ciphertext blocks + vslideup.vi v16, v20, 4 // Setup prev ciphertext blocks + addi t1, t0, -4 + vslidedown.vx v24, v20, t1 // Save last ciphertext block + aes_decrypt v20, \keylen // Decrypt the blocks + vxor.vv v20, v20, v16 // XOR with prev ciphertext blocks + vse32.v v20, (OUTP) // Store plaintext blocks + vmv.v.v v16, v24 // Next "IV" is last ciphertext block + slli t1, t0, 2 // Words to bytes + add INP, INP, t1 + add OUTP, OUTP, t1 + sub LEN, LEN, t0 bnez LEN, 1b + vsetivli zero, 4, e32, m1, ta, ma vse32.v v16, (IVP) // Store next IV ret .endm // void aes_cbc_encrypt_zvkned(const struct crypto_aes_ctx *key, // const u8 *in, u8 *out, size_t len, u8 iv[16]); // // |len| must be nonzero and a multiple of 16 (AES_BLOCK_SIZE). SYM_FUNC_START(aes_cbc_encrypt_zvkned) aes_begin KEYP, 128f, 192f base-commit: cb4ede926134a65bc3bf90ed58dace8451d7e759 -- 2.43.0
