From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:59990 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726778AbgFIH4J (ORCPT ); Tue, 9 Jun 2020 03:56:09 -0400 Subject: Re: [kvm-unit-tests PATCH v8 11/12] s390x: css: msch, enable test References: <1591603981-16879-1-git-send-email-pmorel@linux.ibm.com> <1591603981-16879-12-git-send-email-pmorel@linux.ibm.com> From: Pierre Morel Message-ID: <142b419e-3136-750d-17c4-db17724aa5ee@linux.ibm.com> Date: Tue, 9 Jun 2020 09:56:03 +0200 MIME-Version: 1.0 In-Reply-To: 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: Thomas Huth , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, cohuck@redhat.com On 2020-06-09 09:47, Thomas Huth wrote: > On 08/06/2020 10.13, 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 | 18 ++++++++++++++ >> 2 files changed, 78 insertions(+) >> >> diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c >> index dc5a512..831a116 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); >> + 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); >> + 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; >> +} >> diff --git a/s390x/css.c b/s390x/css.c >> index f0e8f47..6f58d4a 100644 >> --- a/s390x/css.c >> +++ b/s390x/css.c >> @@ -40,11 +40,29 @@ static void test_enumerate(void) >> } >> } >> >> +static void test_enable(void) >> +{ >> + int cc; >> + >> + if (!test_device_sid) { >> + report_skip("No device"); >> + return; >> + } >> + >> + cc = css_enable(test_device_sid); >> + >> + if (cc) >> + report(0, "Failed to enable subchannel %08x", test_device_sid); >> + else >> + report(1, "Subchannel %08x enabled", test_device_sid); > > Could you please write this as: > > report(cc == 1, "Enable subchannel %08x", test_device_sid); > > ... checking for a right value is the whole point of the first parameter > of report() :-) > > Thanks, > Thomas > OK, thanks, Pierre -- Pierre Morel IBM Lab Boeblingen