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45e15c1a |
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23-Jul-2022 |
Guo Ren <guoren@kernel.org> |
csky: Add qspinlock support Enable qspinlock by the requirements mentioned in a8ad07e5240c9 ("asm-generic: qspinlock: Indicate the use of mixed-size atomics"). C-SKY only has "ldex/stex" for all atomic operations. So csky give a strong forward guarantee for "ldex/stex." That means when ldex grabbed the cache line into $L1, it would block other cores from snooping the address with several cycles. The atomic_fetch_add & xchg16 has the same forward guarantee level in C-SKY. Qspinlock has better code size and performance in a fast path. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org>
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8e35ac73 |
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20-Dec-2020 |
Guo Ren <guoren@linux.alibaba.com> |
csky: Cleanup asm/spinlock.h There are two implementation of spinlock in arch/csky: - simple one (NR_CPU = 1,2) - tick's one (NR_CPU = 3,4) Remove the simple one. There is already smp_mb in spinlock, so remove the definition of smp_mb__after_spinlock. Link: https://lore.kernel.org/linux-csky/20200807081253.GD2674@hirez.programming.kicks-ass.net/#t Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Peter Zijlstra <peterz@infradead.org>k Cc: Arnd Bergmann <arnd@arndb.de>
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a0ae6280 |
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05-Sep-2018 |
Guo Ren <ren_guo@c-sky.com> |
csky: Atomic operations This patch adds atomic, cmpxchg, spinlock files. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Cc: Andrea Parri <andrea.parri@amarulasolutions.com> Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
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