[RFC PATCH 0/2] riscv/spinlock,atomic: Miscellaneous fixes

From: Andrea Parri
Date: Mon Mar 05 2018 - 13:23:54 EST


Hi,

This RFC is a follow-up on the discussion in [1], which led to the
discovery of a few issues in the current implementations of RISC-V
locking and atomic operations.

In summary, this series proposes the following modifications:

1. Use lightweigth fences for acquire/release (locking, atomics)

2. Use the combination of .rl and full fences for fully-ordered
atomics implemented with LR/SC pairs.

3. A few style changes (80-chars lines, alignment).

Applies on top of "next-smp_sl_ar".

Cheers,
Andrea

[1] https://marc.info/?l=linux-kernel&m=151930201102853&w=2

Andrea Parri (2):
riscv/spinlock: Strengthen implementations with fences
riscv/atomic: Strengthen implementations with fences

arch/riscv/include/asm/atomic.h | 417 ++++++++++++++++++++++++--------------
arch/riscv/include/asm/cmpxchg.h | 391 ++++++++++++++++++++++++++++-------
arch/riscv/include/asm/fence.h | 12 ++
arch/riscv/include/asm/spinlock.h | 29 +--
4 files changed, 615 insertions(+), 234 deletions(-)
create mode 100644 arch/riscv/include/asm/fence.h

--
2.7.4