From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x244.google.com (mail-pg0-x244.google.com [IPv6:2607:f8b0:400e:c05::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w002C6SFGzDqJx for ; Fri, 7 Apr 2017 22:56:19 +1000 (AEST) Received: by mail-pg0-x244.google.com with SMTP id 81so15433438pgh.3 for ; Fri, 07 Apr 2017 05:56:19 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin , Paul Mackerras , Benjamin Herrenschmidt Subject: [PATCH 1/5] powerpc/pseries: do not use msgsndp doorbells on POWER9 guests Date: Fri, 7 Apr 2017 22:55:58 +1000 Message-Id: <20170407125602.31146-2-npiggin@gmail.com> In-Reply-To: <20170407125602.31146-1-npiggin@gmail.com> References: <20170407125602.31146-1-npiggin@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , POWER9 hypervisors will not necessarily run guest threads together on the same core at the same time, so msgsndp should not be used. Signed-off-by: Nicholas Piggin --- arch/powerpc/platforms/pseries/smp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c index f6f83aeccaaa..1fa08155206b 100644 --- a/arch/powerpc/platforms/pseries/smp.c +++ b/arch/powerpc/platforms/pseries/smp.c @@ -200,7 +200,12 @@ static __init void pSeries_smp_probe(void) { xics_smp_probe(); - if (cpu_has_feature(CPU_FTR_DBELL)) { + /* + * POWER9 can not use msgsndp doorbells for IPI because thread + * siblings do not necessarily run on physical cores at the same + * time. This could be enabled for pHyp. + */ + if (cpu_has_feature(CPU_FTR_DBELL) && !cpu_has_feature(CPU_FTR_ARCH_300)) { xics_cause_ipi = smp_ops->cause_ipi; smp_ops->cause_ipi = pSeries_cause_ipi_mux; } -- 2.11.0