From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:10630 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392619AbhAROEj (ORCPT ); Mon, 18 Jan 2021 09:04:39 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 10IE3Roc060525 for ; Mon, 18 Jan 2021 09:03:59 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3657y36r7m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 18 Jan 2021 09:03:59 -0500 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 10IE3w9B065622 for ; Mon, 18 Jan 2021 09:03:58 -0500 From: Janosch Frank Subject: [kvm-unit-tests PATCH] s390x: Fix uv_call() exception behavior Date: Mon, 18 Jan 2021 09:03:44 -0500 Message-Id: <20210118140344.3074-1-frankja@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-ID: To: kvm390 mailing list Cc: thuth@redhat.com, david@redhat.com, borntraeger@de.ibm.com, imbrenda@linux.ibm.com, cohuck@redhat.com, linux-s390@vger.kernel.org On a program exception we usually skip the instruction that caused the exception and continue. That won't work for UV calls since a "brc 3,0b" will retry the instruction if the CC is > 1. Signed-off-by: Janosch Frank --- I know this isn't very pretty. I'm open for suggestions. --- lib/s390x/asm/uv.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h index 4c2fc48..252f1a3 100644 --- a/lib/s390x/asm/uv.h +++ b/lib/s390x/asm/uv.h @@ -53,21 +53,23 @@ struct uv_cb_share { static inline int uv_call(unsigned long r1, unsigned long r2) { int cc; + struct lowcore *lc = 0x0; /* - * The brc instruction will take care of the cc 2/3 case where - * we need to continue the execution because we were - * interrupted. The inline assembly will only return on - * success/error i.e. cc 0/1. - */ + * CC 2 and 3 tell us to re-execute because the instruction + * hasn't yet finished. + */ + lc->pgm_int_code = 0; +retry: asm volatile( "0: .insn rrf,0xB9A40000,%[r1],%[r2],0,0\n" - " brc 3,0b\n" " ipm %[cc]\n" " srl %[cc],28\n" : [cc] "=d" (cc) : [r1] "a" (r1), [r2] "a" (r2) : "memory", "cc"); + if (!lc->pgm_int_code && cc > 1) + goto retry; return cc; } -- 2.25.1