From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57170 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726480AbgGINMM (ORCPT ); Thu, 9 Jul 2020 09:12:12 -0400 Subject: Re: [kvm-unit-tests PATCH v11 8/9] s390x: css: msch, enable test References: <1594282068-11054-1-git-send-email-pmorel@linux.ibm.com> <1594282068-11054-9-git-send-email-pmorel@linux.ibm.com> <20200709134056.0d267b6c.cohuck@redhat.com> From: Pierre Morel Message-ID: Date: Thu, 9 Jul 2020 15:12:05 +0200 MIME-Version: 1.0 In-Reply-To: <20200709134056.0d267b6c.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com, drjones@redhat.com On 2020-07-09 13:40, Cornelia Huck wrote: > On Thu, 9 Jul 2020 10:07:47 +0200 > Pierre Morel wrote: > >> A second step when testing the channel subsystem is to prepare a channel >> for use. >> This includes: >> - Get the current subchannel Information Block (SCHIB) using STSCH >> - Update it in memory to set the ENABLE bit and the specified ISC >> - Tell the CSS that the SCHIB has been modified using MSCH >> - Get the SCHIB from the CSS again to verify that the subchannel is >> enabled and uses the specified ISC. >> - If the command succeeds but subchannel is not enabled or the ISC >> field is not as expected, retry a predefined retries count. >> - If the command fails, report the failure and do not retry, even >> if cc indicates a busy/status pending as we do not expect this. >> >> This tests the MSCH instruction to enable a channel successfully. >> Retries are done and in case of error, and if the retries count >> is exceeded, a report is made. >> >> Signed-off-by: Pierre Morel >> Acked-by: Thomas Huth >> Reviewed-by: Cornelia Huck >> --- >> lib/s390x/css.h | 8 +++-- >> lib/s390x/css_lib.c | 72 +++++++++++++++++++++++++++++++++++++++++++++ >> s390x/css.c | 15 ++++++++++ >> 3 files changed, 92 insertions(+), 3 deletions(-) > > (...) > >> +/* >> + * css_msch: enable subchannel and set with specified ISC > > "css_enable: enable the subchannel with the specified ISC" > > ? > >> + * @schid: Subchannel Identifier >> + * @isc : number of the interruption subclass to use >> + * Return value: >> + * On success: 0 >> + * On error the CC of the faulty instruction >> + * or -1 if the retry count is exceeded. >> + */ >> +int css_enable(int schid, int isc) >> +{ >> + struct pmcw *pmcw = &schib.pmcw; >> + int retry_count = 0; >> + uint16_t flags; >> + int cc; >> + >> + /* Read the SCHIB for this subchannel */ >> + cc = stsch(schid, &schib); >> + if (cc) { >> + report_info("stsch: sch %08x failed with cc=%d", schid, cc); >> + return cc; >> + } >> + >> + flags = PMCW_ENABLE | (isc << PMCW_ISC_SHIFT); >> + if ((pmcw->flags & flags) == flags) { > > I think you want (pmcw->flags & PMCW_ENABLE) == PMCW_ENABLE -- this > catches the case of "subchannel has been enabled before, but with a > different isc". If with a different ISC, we need to modify the ISC. Don't we ? > >> + report_info("stsch: sch %08x already enabled", schid); >> + return 0; >> + } > > (...) > -- Pierre Morel IBM Lab Boeblingen