From: Pierre Morel <pmorel@linux.ibm.com>
To: kvm@vger.kernel.org
Cc: frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com,
cohuck@redhat.com, imbrenda@linux.ibm.com
Subject: [kvm-unit-tests PATCH v1 1/6] s390x: lib: css: disabling a subchannel
Date: Thu, 18 Mar 2021 14:26:23 +0100 [thread overview]
Message-ID: <1616073988-10381-2-git-send-email-pmorel@linux.ibm.com> (raw)
In-Reply-To: <1616073988-10381-1-git-send-email-pmorel@linux.ibm.com>
Some tests require to disable a subchannel.
Let's implement the css_disable() function.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
lib/s390x/css.h | 1 +
lib/s390x/css_lib.c | 69 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 70 insertions(+)
diff --git a/lib/s390x/css.h b/lib/s390x/css.h
index 7e3d261..b0de3a3 100644
--- a/lib/s390x/css.h
+++ b/lib/s390x/css.h
@@ -284,6 +284,7 @@ int css_enumerate(void);
#define IO_SCH_ISC 3
int css_enable(int schid, int isc);
bool css_enabled(int schid);
+int css_disable(int schid);
/* Library functions */
int start_ccw1_chain(unsigned int sid, struct ccw1 *ccw);
diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
index efc7057..f8db205 100644
--- a/lib/s390x/css_lib.c
+++ b/lib/s390x/css_lib.c
@@ -186,6 +186,75 @@ bool css_enabled(int schid)
}
return true;
}
+
+/*
+ * css_disable: disable the subchannel
+ * @schid: Subchannel Identifier
+ * Return value:
+ * On success: 0
+ * On error the CC of the faulty instruction
+ * or -1 if the retry count is exceeded.
+ */
+int css_disable(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: sch %08x failed with cc=%d", schid, cc);
+ return cc;
+ }
+
+ if (!(pmcw->flags & PMCW_ENABLE)) {
+ report_info("stsch: sch %08x already disabled", schid);
+ return 0;
+ }
+
+retry:
+ /* Update the SCHIB to disable the subchannel */
+ 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: sch %08x failed with cc=%d", schid, cc);
+ return cc;
+ }
+
+ /*
+ * Read the SCHIB again to verify the enablement
+ */
+ cc = stsch(schid, &schib);
+ if (cc) {
+ report_info("stsch: updating sch %08x failed with cc=%d",
+ schid, cc);
+ return cc;
+ }
+
+ if (!(pmcw->flags & PMCW_ENABLE)) {
+ if (retry_count)
+ report_info("stsch: sch %08x successfully disabled 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: modifying sch %08x failed after %d retries. pmcw flags: %04x",
+ schid, retry_count, pmcw->flags);
+ return -1;
+}
/*
* css_enable: enable the subchannel with the specified ISC
* @schid: Subchannel Identifier
--
2.17.1
next prev parent reply other threads:[~2021-03-18 13:27 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 13:26 [kvm-unit-tests PATCH v1 0/6] Testing SSCH, CSCH and HSCH for errors Pierre Morel
2021-03-18 13:26 ` Pierre Morel [this message]
2021-03-19 9:02 ` [kvm-unit-tests PATCH v1 1/6] s390x: lib: css: disabling a subchannel Janosch Frank
2021-03-19 9:11 ` Pierre Morel
2021-03-19 10:03 ` Cornelia Huck
2021-03-19 10:11 ` Pierre Morel
2021-03-19 15:29 ` Pierre Morel
2021-03-18 13:26 ` [kvm-unit-tests PATCH v1 2/6] s390x: lib: css: SCSW bit definitions Pierre Morel
2021-03-19 10:16 ` Cornelia Huck
2021-03-19 15:30 ` Pierre Morel
2021-03-18 13:26 ` [kvm-unit-tests PATCH v1 3/6] s390x: lib: css: upgrading IRQ handling Pierre Morel
2021-03-18 14:22 ` Pierre Morel
2021-03-19 11:01 ` Cornelia Huck
2021-03-19 15:55 ` Pierre Morel
2021-03-19 16:09 ` Cornelia Huck
2021-03-19 16:34 ` Pierre Morel
2021-03-18 13:26 ` [kvm-unit-tests PATCH v1 4/6] s390x: lib: css: add expectations to wait for interrupt Pierre Morel
2021-03-19 9:09 ` Janosch Frank
2021-03-19 9:50 ` Pierre Morel
2021-03-19 11:23 ` Cornelia Huck
2021-03-19 16:18 ` Pierre Morel
2021-03-18 13:26 ` [kvm-unit-tests PATCH v1 5/6] s390x: css: testing ssch error response Pierre Morel
2021-03-19 9:18 ` Janosch Frank
2021-03-19 10:02 ` Pierre Morel
2021-03-18 13:26 ` [kvm-unit-tests PATCH v1 6/6] s390x: css: testing clear and halt subchannel Pierre Morel
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