Unverified Commit 4ff4c745 authored by Andrea Parri's avatar Andrea Parri Committed by Palmer Dabbelt
Browse files

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: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarAndrea Parri <parri.andrea@gmail.com>
Reviewed-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20240131144936.29190-4-parri.andrea@gmail.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent a14d11a0

include/linux/sync_core.h

+15 −1
Original line number Diff line number Diff line
@@ -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 <asm/sync_core.h>

#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 */

init/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -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

kernel/sched/membarrier.c

+1 −0
Original line number Diff line number Diff line
@@ -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;