diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2024-03-18 01:27:35 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2024-09-13 07:10:37 -0700 |
| commit | f2519d4d4fc4d36f2b58c5614357de9f5b4032fc (patch) | |
| tree | d6d437ed485ee3c2b676da43e15ab3437ee77de2 | |
| parent | 8400291e289ee6b2bf9779ff1c83a291501f017b (diff) | |
ARC: Emulate one-byte cmpxchg
Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on arc.
[ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]
[ paulmck: Apply feedback from Naresh Kamboju. ]
[ paulmck: Apply kernel test robot feedback. ]
[ paulmck: Apply feedback from Vineet Gupta. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: <linux-snps-arc@lists.infradead.org>
Acked-by: Vineet Gupta <vgupta@kernel.org>
| -rw-r--r-- | arch/arc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arc/include/asm/cmpxchg.h | 6 |
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index fd0b0a0d4686..163608fd49d1 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -13,6 +13,7 @@ config ARC select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYNC_DMA_FOR_DEVICE + select ARCH_NEED_CMPXCHG_1_EMU select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC select ARCH_32BIT_OFF_T select BUILDTIME_TABLE_SORT diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index e138fde067de..58045c898340 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -8,6 +8,7 @@ #include <linux/build_bug.h> #include <linux/types.h> +#include <linux/cmpxchg-emu.h> #include <asm/barrier.h> #include <asm/smp.h> @@ -46,6 +47,9 @@ __typeof__(*(ptr)) _prev_; \ \ switch(sizeof((_p_))) { \ + case 1: \ + _prev_ = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *)_p_, (uintptr_t)_o_, (uintptr_t)_n_); \ + break; \ case 4: \ _prev_ = __cmpxchg(_p_, _o_, _n_); \ break; \ @@ -65,8 +69,6 @@ __typeof__(*(ptr)) _prev_; \ unsigned long __flags; \ \ - BUILD_BUG_ON(sizeof(_p_) != 4); \ - \ /* \ * spin lock/unlock provide the needed smp_mb() before/after \ */ \ |