Re: [PATCH v5 4/7] powerpc/qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32

2021-03-28 Thread Guo Ren
On Sun, Mar 28, 2021 at 7:14 PM Christophe Leroy wrote: > > > > Le 28/03/2021 à 08:30, guo...@kernel.org a écrit : > > From: Guo Ren > > > > We don't have native hw xchg16 instruction, so let qspinlock > > generic code to deal with it. > > We have lharx/sthcx pair on some versions of powerpc. >

Re: [PATCH v5 4/7] powerpc/qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32

2021-03-28 Thread Christophe Leroy
Le 28/03/2021 à 08:30, guo...@kernel.org a écrit : From: Guo Ren We don't have native hw xchg16 instruction, so let qspinlock generic code to deal with it. We have lharx/sthcx pair on some versions of powerpc. See

[PATCH v5 4/7] powerpc/qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32

2021-03-28 Thread guoren
From: Guo Ren We don't have native hw xchg16 instruction, so let qspinlock generic code to deal with it. Using the full-word atomic xchg instructions implement xchg16 has the semantic risk for atomic operations. This patch cancels the dependency of on qspinlock generic code on architecture's