[PATCH 0/2] Implementing bitops rotate using riscv Zbb extension

cp0613 at linux.alibaba.com cp0613 at linux.alibaba.com
Fri Jun 20 04:16:08 PDT 2025


From: Chen Pei <cp0613 at linux.alibaba.com>

This patch series moves the ror*/rol* functions from include/linux/bitops.h
to include/asm-generic/bitops/rotate.h as a generic implementation.

At the same time, an optimized implementation is made based on the bitwise
rotation instructions provided by the RISC-V Zbb extension[1].

Based on the RISC-V processor XUANTIE C908, I tested the performance of
sha3_generic. Compared with the generic implementation, the RISC-V Zbb
instruction implementation performance increased by an average of 6.87%.

Test method:
1. CONFIG_CRYPTO_TEST=m
2. modprobe tcrypt mode=322 sec=3
Different parameters will be selected to test the performance of sha3-224.

[1] https://github.com/riscv/riscv-bitmanip/

Chen Pei (2):
  bitops: generic rotate
  bitops: rotate: Add riscv implementation using Zbb extension

 arch/riscv/include/asm/bitops.h     | 127 ++++++++++++++++++++++++++++
 include/asm-generic/bitops.h        |   2 +-
 include/asm-generic/bitops/rotate.h |  97 +++++++++++++++++++++
 include/linux/bitops.h              |  80 ------------------
 tools/include/asm-generic/bitops.h  |   2 +-
 5 files changed, 226 insertions(+), 82 deletions(-)
 create mode 100644 include/asm-generic/bitops/rotate.h

-- 
2.49.0




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