diff mbox series

[kvm-unit-tests,v7,09/12] s390x: css: msch, enable test

Message ID 1589818051-20549-10-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 May 18, 2020, 4:07 p.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 subchannel is not enabled retry a predefined retries count.

This tests the MSCH instruction to enable a channel succesfuly.
This is NOT a routine to really enable the channel, no retry is done,
in case of error, a report is made.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 s390x/css.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

Comments

Cornelia Huck May 27, 2020, 9:42 a.m. UTC | #1
On Mon, 18 May 2020 18:07:28 +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 subchannel is not enabled retry a predefined retries count.
> 
> This tests the MSCH instruction to enable a channel succesfuly.
> This is NOT a routine to really enable the channel, no retry is done,
> in case of error, a report is made.

Hm... so you retry if the subchannel is not enabled after cc 0, but you
don't retry if the cc indicates busy/status pending? Makes sense, as we
don't expect the subchannel to be busy, but a more precise note in the
patch description would be good :)

> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  s390x/css.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 67 insertions(+)
> 
> diff --git a/s390x/css.c b/s390x/css.c
> index d7989d8..1b60a47 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -16,6 +16,7 @@
>  #include <string.h>
>  #include <interrupt.h>
>  #include <asm/arch_def.h>
> +#include <asm/time.h>
>  
>  #include <css.h>
>  
> @@ -65,11 +66,77 @@ out:
>  	       scn, scn_found, dev_found);
>  }
>  
> +#define MAX_ENABLE_RETRIES	5
> +static void test_enable(void)
> +{
> +	struct pmcw *pmcw = &schib.pmcw;
> +	int retry_count = 0;
> +	int cc;
> +
> +	if (!test_device_sid) {
> +		report_skip("No device");
> +		return;
> +	}
> +
> +	/* Read the SCHIB for this subchannel */
> +	cc = stsch(test_device_sid, &schib);
> +	if (cc) {
> +		report(0, "stsch cc=%d", cc);
> +		return;
> +	}
> +
> +	if (pmcw->flags & PMCW_ENABLE) {
> +		report(1, "stsch: sch %08x already enabled", test_device_sid);
> +		return;
> +	}
> +
> +retry:
> +	/* Update the SCHIB to enable the channel */
> +	pmcw->flags |= PMCW_ENABLE;
> +
> +	/* Tell the CSS we want to modify the subchannel */
> +	cc = msch(test_device_sid, &schib);
> +	if (cc) {
> +		/*
> +		 * If the subchannel is status pending or
> +		 * if a function is in progress,
> +		 * we consider both cases as errors.

Could also be cc 3, but that would be even more weird. Just logging the
cc seems fine, though.

> +		 */
> +		report(0, "msch cc=%d", cc);
> +		return;
> +	}
> +
> +	/*
> +	 * Read the SCHIB again to verify the enablement
> +	 */
> +	cc = stsch(test_device_sid, &schib);
> +	if (cc) {
> +		report(0, "stsch cc=%d", cc);
> +		return;
> +	}
> +
> +	if (pmcw->flags & PMCW_ENABLE) {
> +		report(1, "msch: sch %08x enabled after %d retries",
> +		       test_device_sid, retry_count);
> +		return;
> +	}
> +
> +	if (retry_count++ < MAX_ENABLE_RETRIES) {
> +		mdelay(10); /* the hardware was not ready, let it some time */

s/let/give/

> +		goto retry;
> +	}
> +
> +	report(0,
> +	       "msch: enabling sch %08x failed after %d retries. pmcw: %x",
> +	       test_device_sid, retry_count, pmcw->flags);
> +}
> +
>  static struct {
>  	const char *name;
>  	void (*func)(void);
>  } tests[] = {
>  	{ "enumerate (stsch)", test_enumerate },
> +	{ "enable (msch)", test_enable },
>  	{ NULL, NULL }
>  };
>  

Otherwise,
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Pierre Morel June 4, 2020, 12:46 p.m. UTC | #2
On 2020-05-27 11:42, Cornelia Huck wrote:
> On Mon, 18 May 2020 18:07:28 +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 subchannel is not enabled retry a predefined retries count.
>>
>> This tests the MSCH instruction to enable a channel succesfuly.
>> This is NOT a routine to really enable the channel, no retry is done,
>> in case of error, a report is made.
> 
> Hm... so you retry if the subchannel is not enabled after cc 0, but you
> don't retry if the cc indicates busy/status pending? Makes sense, as we
> don't expect the subchannel to be busy, but a more precise note in the
> patch description would be good :)

OK, I add something like
"
- If the command succeed 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 as we do not expect this.
"

> 
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   s390x/css.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 67 insertions(+)
>>
>> diff --git a/s390x/css.c b/s390x/css.c
>> index d7989d8..1b60a47 100644
>> --- a/s390x/css.c
>> +++ b/s390x/css.c
>> @@ -16,6 +16,7 @@
>>   #include <string.h>
>>   #include <interrupt.h>
>>   #include <asm/arch_def.h>
>> +#include <asm/time.h>
>>   
>>   #include <css.h>
>>   
>> @@ -65,11 +66,77 @@ out:
>>   	       scn, scn_found, dev_found);
>>   }
>>   
>> +#define MAX_ENABLE_RETRIES	5
>> +static void test_enable(void)
>> +{
>> +	struct pmcw *pmcw = &schib.pmcw;
>> +	int retry_count = 0;
>> +	int cc;
>> +
>> +	if (!test_device_sid) {
>> +		report_skip("No device");
>> +		return;
>> +	}
>> +
>> +	/* Read the SCHIB for this subchannel */
>> +	cc = stsch(test_device_sid, &schib);
>> +	if (cc) {
>> +		report(0, "stsch cc=%d", cc);
>> +		return;
>> +	}
>> +
>> +	if (pmcw->flags & PMCW_ENABLE) {
>> +		report(1, "stsch: sch %08x already enabled", test_device_sid);
>> +		return;
>> +	}
>> +
>> +retry:
>> +	/* Update the SCHIB to enable the channel */
>> +	pmcw->flags |= PMCW_ENABLE;
>> +
>> +	/* Tell the CSS we want to modify the subchannel */
>> +	cc = msch(test_device_sid, &schib);
>> +	if (cc) {
>> +		/*
>> +		 * If the subchannel is status pending or
>> +		 * if a function is in progress,
>> +		 * we consider both cases as errors.
> 
> Could also be cc 3, but that would be even more weird. Just logging the
> cc seems fine, though.
> 
>> +		 */
>> +		report(0, "msch cc=%d", cc);
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * Read the SCHIB again to verify the enablement
>> +	 */
>> +	cc = stsch(test_device_sid, &schib);
>> +	if (cc) {
>> +		report(0, "stsch cc=%d", cc);
>> +		return;
>> +	}
>> +
>> +	if (pmcw->flags & PMCW_ENABLE) {
>> +		report(1, "msch: sch %08x enabled after %d retries",
>> +		       test_device_sid, retry_count);
>> +		return;
>> +	}
>> +
>> +	if (retry_count++ < MAX_ENABLE_RETRIES) {
>> +		mdelay(10); /* the hardware was not ready, let it some time */
> 
> s/let/give/
> 
>> +		goto retry;
>> +	}
>> +
>> +	report(0,
>> +	       "msch: enabling sch %08x failed after %d retries. pmcw: %x",
>> +	       test_device_sid, retry_count, pmcw->flags);
>> +}
>> +
>>   static struct {
>>   	const char *name;
>>   	void (*func)(void);
>>   } tests[] = {
>>   	{ "enumerate (stsch)", test_enumerate },
>> +	{ "enable (msch)", test_enable },
>>   	{ NULL, NULL }
>>   };
>>   
> 
> Otherwise,
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

Thanks a lot.
I make the corrections.

regards,
Pierre
Cornelia Huck June 4, 2020, 1:29 p.m. UTC | #3
On Thu, 4 Jun 2020 14:46:05 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> On 2020-05-27 11:42, Cornelia Huck wrote:
> > On Mon, 18 May 2020 18:07:28 +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 subchannel is not enabled retry a predefined retries count.
> >>
> >> This tests the MSCH instruction to enable a channel succesfuly.
> >> This is NOT a routine to really enable the channel, no retry is done,
> >> in case of error, a report is made.  
> > 
> > Hm... so you retry if the subchannel is not enabled after cc 0, but you
> > don't retry if the cc indicates busy/status pending? Makes sense, as we
> > don't expect the subchannel to be busy, but a more precise note in the
> > patch description would be good :)  
> 
> OK, I add something like
> "
> - If the command succeed but subchannel is not enabled retry a

s/succeed/succeeds/ :)

>    predefined retries count.
> - If the command fails, report the failure and do not retry, even
>    if cc indicates a busy/status as we do not expect this.

"indicates busy/status pending" ?

> "
Pierre Morel June 5, 2020, 7:37 a.m. UTC | #4
On 2020-06-04 15:29, Cornelia Huck wrote:
> On Thu, 4 Jun 2020 14:46:05 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> On 2020-05-27 11:42, Cornelia Huck wrote:
>>> On Mon, 18 May 2020 18:07:28 +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 subchannel is not enabled retry a predefined retries count.
>>>>
>>>> This tests the MSCH instruction to enable a channel succesfuly.
>>>> This is NOT a routine to really enable the channel, no retry is done,
>>>> in case of error, a report is made.
>>>
>>> Hm... so you retry if the subchannel is not enabled after cc 0, but you
>>> don't retry if the cc indicates busy/status pending? Makes sense, as we
>>> don't expect the subchannel to be busy, but a more precise note in the
>>> patch description would be good :)
>>
>> OK, I add something like
>> "
>> - If the command succeed but subchannel is not enabled retry a
> 
> s/succeed/succeeds/ :)
> 
>>     predefined retries count.
>> - If the command fails, report the failure and do not retry, even
>>     if cc indicates a busy/status as we do not expect this.
> 
> "indicates busy/status pending" ?
> 
>> "
> 
done, thanks,

Pierre
Pierre Morel June 5, 2020, 8:24 a.m. UTC | #5
Hi Connie,

for the next series, I will move more code of the css.c to the css_lib.c 
to be able to reuse it for other tests.
One of your suggestions IIRC.
So I will not be able to keep your RB until you have a look at the changes.
I will keep the same algorithms but still...

regards,
Pierre

On 2020-06-05 09:37, Pierre Morel wrote:
> 
> 
> On 2020-06-04 15:29, Cornelia Huck wrote:
>> On Thu, 4 Jun 2020 14:46:05 +0200
>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>
>>> On 2020-05-27 11:42, Cornelia Huck wrote:
>>>> On Mon, 18 May 2020 18:07:28 +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 subchannel is not enabled retry a predefined retries count.
>>>>>
>>>>> This tests the MSCH instruction to enable a channel succesfuly.
>>>>> This is NOT a routine to really enable the channel, no retry is done,
>>>>> in case of error, a report is made.
>>>>
>>>> Hm... so you retry if the subchannel is not enabled after cc 0, but you
>>>> don't retry if the cc indicates busy/status pending? Makes sense, as we
>>>> don't expect the subchannel to be busy, but a more precise note in the
>>>> patch description would be good :)
>>>
>>> OK, I add something like
>>> "
>>> - If the command succeed but subchannel is not enabled retry a
>>
>> s/succeed/succeeds/ :)
>>
>>>     predefined retries count.
>>> - If the command fails, report the failure and do not retry, even
>>>     if cc indicates a busy/status as we do not expect this.
>>
>> "indicates busy/status pending" ?
>>
>>> "
>>
> done, thanks,
> 
> Pierre
>
Cornelia Huck June 5, 2020, 9 a.m. UTC | #6
On Fri, 5 Jun 2020 10:24:56 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> Hi Connie,
> 
> for the next series, I will move more code of the css.c to the css_lib.c 
> to be able to reuse it for other tests.
> One of your suggestions IIRC.
> So I will not be able to keep your RB until you have a look at the changes.
> I will keep the same algorithms but still...

np, I'll look at it again.
diff mbox series

Patch

diff --git a/s390x/css.c b/s390x/css.c
index d7989d8..1b60a47 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -16,6 +16,7 @@ 
 #include <string.h>
 #include <interrupt.h>
 #include <asm/arch_def.h>
+#include <asm/time.h>
 
 #include <css.h>
 
@@ -65,11 +66,77 @@  out:
 	       scn, scn_found, dev_found);
 }
 
+#define MAX_ENABLE_RETRIES	5
+static void test_enable(void)
+{
+	struct pmcw *pmcw = &schib.pmcw;
+	int retry_count = 0;
+	int cc;
+
+	if (!test_device_sid) {
+		report_skip("No device");
+		return;
+	}
+
+	/* Read the SCHIB for this subchannel */
+	cc = stsch(test_device_sid, &schib);
+	if (cc) {
+		report(0, "stsch cc=%d", cc);
+		return;
+	}
+
+	if (pmcw->flags & PMCW_ENABLE) {
+		report(1, "stsch: sch %08x already enabled", test_device_sid);
+		return;
+	}
+
+retry:
+	/* Update the SCHIB to enable the channel */
+	pmcw->flags |= PMCW_ENABLE;
+
+	/* Tell the CSS we want to modify the subchannel */
+	cc = msch(test_device_sid, &schib);
+	if (cc) {
+		/*
+		 * If the subchannel is status pending or
+		 * if a function is in progress,
+		 * we consider both cases as errors.
+		 */
+		report(0, "msch cc=%d", cc);
+		return;
+	}
+
+	/*
+	 * Read the SCHIB again to verify the enablement
+	 */
+	cc = stsch(test_device_sid, &schib);
+	if (cc) {
+		report(0, "stsch cc=%d", cc);
+		return;
+	}
+
+	if (pmcw->flags & PMCW_ENABLE) {
+		report(1, "msch: sch %08x enabled after %d retries",
+		       test_device_sid, retry_count);
+		return;
+	}
+
+	if (retry_count++ < MAX_ENABLE_RETRIES) {
+		mdelay(10); /* the hardware was not ready, let it some time */
+		goto retry;
+	}
+
+	report(0,
+	       "msch: enabling sch %08x failed after %d retries. pmcw: %x",
+	       test_device_sid, retry_count, pmcw->flags);
+}
+
 static struct {
 	const char *name;
 	void (*func)(void);
 } tests[] = {
 	{ "enumerate (stsch)", test_enumerate },
+	{ "enable (msch)", test_enable },
 	{ NULL, NULL }
 };