From 4ff4c745a16c4c151a71863420811e7f406c3ec2 Mon Sep 17 00:00:00 2001 From: Andrea Parri Date: Wed, 31 Jan 2024 15:49:35 +0100 Subject: locking: Introduce prepare_sync_core_cmd() Introduce an architecture function that architectures can use to set up ("prepare") SYNC_CORE commands. The function will be used by RISC-V to update its "deferred icache- flush" data structures (icache_stale_mask). Architectures defining prepare_sync_core_cmd() static inline need to select ARCH_HAS_PREPARE_SYNC_CORE_CMD. Suggested-by: Mathieu Desnoyers Signed-off-by: Andrea Parri Reviewed-by: Mathieu Desnoyers Link: https://lore.kernel.org/r/20240131144936.29190-4-parri.andrea@gmail.com Signed-off-by: Palmer Dabbelt --- include/linux/sync_core.h | 16 +++++++++++++++- init/Kconfig | 3 +++ kernel/sched/membarrier.c | 1 + 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/include/linux/sync_core.h b/include/linux/sync_core.h index 013da4b8b327..67bb9794b875 100644 --- a/include/linux/sync_core.h +++ b/include/linux/sync_core.h @@ -17,5 +17,19 @@ static inline void sync_core_before_usermode(void) } #endif -#endif /* _LINUX_SYNC_CORE_H */ +#ifdef CONFIG_ARCH_HAS_PREPARE_SYNC_CORE_CMD +#include +#else +/* + * This is a dummy prepare_sync_core_cmd() implementation that can be used on + * all architectures which provide unconditional core serializing instructions + * in switch_mm(). + * If your architecture doesn't provide such core serializing instructions in + * switch_mm(), you may need to write your own functions. + */ +static inline void prepare_sync_core_cmd(struct mm_struct *mm) +{ +} +#endif +#endif /* _LINUX_SYNC_CORE_H */ diff --git a/init/Kconfig b/init/Kconfig index 8df18f3a9748..c3994b92333d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1970,6 +1970,9 @@ source "kernel/Kconfig.locks" config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE bool +config ARCH_HAS_PREPARE_SYNC_CORE_CMD + bool + config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE bool diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index f3d91628d6b8..6d1f31b3a967 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -320,6 +320,7 @@ static int membarrier_private_expedited(int flags, int cpu_id) MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY)) return -EPERM; ipi_func = ipi_sync_core; + prepare_sync_core_cmd(mm); } else if (flags == MEMBARRIER_FLAG_RSEQ) { if (!IS_ENABLED(CONFIG_RSEQ)) return -EINVAL; -- cgit v1.2.3