From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-2.mimecast.com ([205.139.110.61]:42896 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725846AbgFQIyr (ORCPT ); Wed, 17 Jun 2020 04:54:47 -0400 Date: Wed, 17 Jun 2020 10:54:33 +0200 From: Cornelia Huck Subject: Re: [kvm-unit-tests PATCH v9 11/12] s390x: css: msch, enable test Message-ID: <20200617105433.6a79e92c.cohuck@redhat.com> In-Reply-To: <1592213521-19390-12-git-send-email-pmorel@linux.ibm.com> References: <1592213521-19390-1-git-send-email-pmorel@linux.ibm.com> <1592213521-19390-12-git-send-email-pmorel@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Pierre Morel Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com On Mon, 15 Jun 2020 11:32:00 +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 > - 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. > - If the command succeeds but subchannel is not enabled 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 succesfuly. > This some retries are done and in case of error, and if the retries > count is exceeded, a report is made. > > Signed-off-by: Pierre Morel > --- > lib/s390x/css_lib.c | 60 +++++++++++++++++++++++++++++++++++++++++++++ > s390x/css.c | 15 ++++++++++++ > 2 files changed, 75 insertions(+) > > diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c > index b0a0294..06a76db 100644 > --- a/lib/s390x/css_lib.c > +++ b/lib/s390x/css_lib.c > @@ -15,6 +15,7 @@ > #include > #include > #include > +#include > > #include > > @@ -68,3 +69,62 @@ out: > scn, scn_found, dev_found); > return schid; > } > + > +int css_enable(int schid) > +{ > + struct pmcw *pmcw = &schib.pmcw; > + int retry_count = 0; > + int cc; > + > + /* Read the SCHIB for this subchannel */ > + cc = stsch(schid, &schib); > + if (cc) { > + report_info("stsch failed with cc=%d", cc); Mention the schid in the message? > + return cc; > + } > + > + if (pmcw->flags & PMCW_ENABLE) { > + report_info("stsch: sch %08x already enabled", schid); > + return 0; > + } > + > +retry: > + /* Update the SCHIB to enable the channel */ > + pmcw->flags |= PMCW_ENABLE; > + > + /* Tell the CSS we want to modify the subchannel */ > + cc = msch(schid, &schib); > + if (cc) { > + /* > + * If the subchannel is status pending or > + * if a function is in progress, > + * we consider both cases as errors. > + */ > + report_info("msch failed with cc=%d", cc); > + return cc; > + } > + > + /* > + * Read the SCHIB again to verify the enablement > + */ > + cc = stsch(schid, &schib); > + if (cc) { > + report_info("stsch failed with cc=%d", cc); Also add the schid here? Maybe also add a marker to distinguish the two cases? > + return cc; > + } > + > + if (pmcw->flags & PMCW_ENABLE) { > + report_info("Subchannel %08x enabled after %d retries", > + schid, retry_count); > + return 0; > + } > + > + if (retry_count++ < MAX_ENABLE_RETRIES) { > + mdelay(10); /* the hardware was not ready, give it some time */ > + goto retry; > + } > + > + report_info("msch: enabling sch %08x failed after %d retries. pmcw flags: %x", > + schid, retry_count, pmcw->flags); > + return -1; > +} With the messages updated, Reviewed-by: Cornelia Huck