From e688c6255b742428ea8fa7e4fb8181a6135205e9 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 27 Feb 2023 18:56:10 +0100 Subject: [PATCH] s390/smp: perform cpu reset before delegating work to target cpu Clear CPU state (e.g. all TLB entries, prefetched instructions, etc.) of the target CPU, however without clearing register contents before starting any work on it. This puts the target CPU in a more defined state compared to the current Stop + Restart sigp orders. Signed-off-by: Heiko Carstens --- arch/s390/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 97961522b317..d4888453bbf8 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -333,6 +333,7 @@ static void pcpu_delegate(struct pcpu *pcpu, } /* Stop target cpu (if func returns this stops the current cpu). */ pcpu_sigp_retry(pcpu, SIGP_STOP, 0); + pcpu_sigp_retry(pcpu, SIGP_CPU_RESET, 0); /* Restart func on the target cpu and stop the current cpu. */ if (lc) { lc->restart_stack = stack; -- GitLab