[V3,0/5] riscv: atomic: Optimize AMO instructions usage

Message

Guo Ren April 20, 2022, 2:44 p.m. UTC

From: Guo Ren <[e-mail]>

These patch series contain one cleanup and some optimizations for
atomic operations.

Changes in V3:
 - Fixup usage of lr.rl & sc.aq with violation of ISA
 - Add Optimize dec_if_positive functions
 - Add conditional atomic operations' optimization

Changes in V2:
 - Fixup LR/SC memory barrier semantic problems which pointed by
   Rutland
 - Combine patches into one patchset series
 - Separate AMO optimization & LRSC optimization for convenience
   patch review

Guo Ren (5):
  riscv: atomic: Cleanup unnecessary definition
  riscv: atomic: Optimize acquire and release for AMO operations
  riscv: atomic: Optimize memory barrier semantics of LRSC-pairs
  riscv: atomic: Optimize dec_if_positive functions
  riscv: atomic: Add conditional atomic operations' optimization

 arch/riscv/include/asm/atomic.h  | 168 ++++++++++++++++++++++++++++---
 arch/riscv/include/asm/cmpxchg.h |  30 ++----
 2 files changed, 160 insertions(+), 38 deletions(-)