diff mbox series

[kvm-unit-tests,v9,11/12] s390x: css: msch, enable test

Message ID 1592213521-19390-12-git-send-email-pmorel@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: Testing the Channel Subsystem I/O | expand

Commit Message

Pierre Morel June 15, 2020, 9:32 a.m. UTC
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 <pmorel@linux.ibm.com>
---
 lib/s390x/css_lib.c | 60 +++++++++++++++++++++++++++++++++++++++++++++
 s390x/css.c         | 15 ++++++++++++
 2 files changed, 75 insertions(+)

Comments

Thomas Huth June 16, 2020, 11:43 a.m. UTC | #1
On 15/06/2020 11.32, 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.

s/succesfuly/successfully/

> This some retries are done and in case of error, and if the retries
> count is exceeded, a report is made.

That sentence needs some fixes, too ;-)

With the commit description fixed:

Acked-by: Thomas Huth <thuth@redhat.com>
Pierre Morel June 16, 2020, 1:43 p.m. UTC | #2
On 2020-06-16 13:43, Thomas Huth wrote:
> On 15/06/2020 11.32, 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.
> 
> s/succesfuly/successfully/

yes.

> 
>> This some retries are done and in case of error, and if the retries
>> count is exceeded, a report is made.
> 
> That sentence needs some fixes, too ;-)
> 
> With the commit description fixed:
> 
> Acked-by: Thomas Huth <thuth@redhat.com>
> 

Thanks,
Pierre
Cornelia Huck June 17, 2020, 8:54 a.m. UTC | #3
On Mon, 15 Jun 2020 11:32:00 +0200
Pierre Morel <pmorel@linux.ibm.com> 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 <pmorel@linux.ibm.com>
> ---
>  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 <string.h>
>  #include <interrupt.h>
>  #include <asm/arch_def.h>
> +#include <asm/time.h>
>  
>  #include <css.h>
>  
> @@ -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 <cohuck@redhat.com>
Pierre Morel June 17, 2020, 11:25 a.m. UTC | #4
On 2020-06-17 10:54, Cornelia Huck wrote:
> On Mon, 15 Jun 2020 11:32:00 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> A second step when testing the channel subsystem is to prepare a channel
>> for use.
...snip...
>> +
>> +	/* 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?

Yes:
report_info("stsch: sch %08x failed with cc=%d", schid, 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);

added schid here too

>> +		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?

changed to:
report_info("stsch: updating sch %08x failed with cc=%d",schid, 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;
>> +}
> 
> With the messages updated,
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

Thanks,
Pierre
diff mbox series

Patch

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 <string.h>
 #include <interrupt.h>
 #include <asm/arch_def.h>
+#include <asm/time.h>
 
 #include <css.h>
 
@@ -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 230adf5..6948d73 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -31,11 +31,26 @@  static void test_enumerate(void)
 	report(0, "No I/O device found");
 }
 
+static void test_enable(void)
+{
+	int cc;
+
+	if (!test_device_sid) {
+		report_skip("No device");
+		return;
+	}
+
+	cc = css_enable(test_device_sid);
+
+	report(cc == 0, "Enable subchannel %08x", test_device_sid);
+}
+
 static struct {
 	const char *name;
 	void (*func)(void);
 } tests[] = {
 	{ "enumerate (stsch)", test_enumerate },
+	{ "enable (msch)", test_enable },
 	{ NULL, NULL }
 };