diff mbox series

[kvm-unit-tests,v2,1/8] s390x: lib: css: disabling a subchannel

Message ID 1616665147-32084-2-git-send-email-pmorel@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series Testing SSCH, CSCH and HSCH for errors | expand

Commit Message

Pierre Morel March 25, 2021, 9:39 a.m. UTC 
Some tests require to disable a subchannel.
Let's implement the css_disable() function.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
 lib/s390x/css.h     |  1 +
 lib/s390x/css_lib.c | 67 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

Comments

Claudio Imbrenda March 25, 2021, 2:52 p.m. UTC | #1 
On Thu, 25 Mar 2021 10:39:00 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:

> Some tests require to disable a subchannel.
> Let's implement the css_disable() function.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> ---
>  lib/s390x/css.h     |  1 +
>  lib/s390x/css_lib.c | 67
> +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 68
> 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..f5c4f37 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -186,6 +186,73 @@ 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);

KVM unit tests allow up to 120 columns per line, please use them, the
code will be more readable; this applies for all broken lines, not just
in this patch.

> +		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 the subchannel is status pending or if a function is
> in progress,
> +	 * we consider both cases as errors.
> +	 */
> +	if (cc) {
> +		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) {
> +		/* the hardware was not ready, give it some time */
> +		mdelay(10);
> +		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
Pierre Morel March 25, 2021, 4:10 p.m. UTC | #2 
On 3/25/21 3:52 PM, Claudio Imbrenda wrote:
> On Thu, 25 Mar 2021 10:39:00 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> Some tests require to disable a subchannel.
>> Let's implement the css_disable() function.
>>
...snip...
>> +	/* Read the SCHIB for this subchannel */
>> +	cc = stsch(schid, &schib);
>> +	if (cc) {
>> +		report_info("stsch: sch %08x failed with cc=%d",
>> schid, cc);
> 
> KVM unit tests allow up to 120 columns per line, please use them, the
> code will be more readable; this applies for all broken lines, not just
> in this patch.

Oh someone did not read the README!
thanks.
Janosch Frank March 26, 2021, 8:26 a.m. UTC | #3 
On 3/25/21 10:39 AM, Pierre Morel wrote:
> Some tests require to disable a subchannel.
> Let's implement the css_disable() function.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>

Acked-by: Janosch Frank <frankja@linux.ibm.com>

> ---
>  lib/s390x/css.h     |  1 +
>  lib/s390x/css_lib.c | 67 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 68 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..f5c4f37 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -186,6 +186,73 @@ 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 the subchannel is status pending or if a function is in progress,
> +	 * we consider both cases as errors.
> +	 */
> +	if (cc) {
> +		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) {
> +		/* the hardware was not ready, give it some time */
> +		mdelay(10);
> +		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
>
Pierre Morel March 26, 2021, 9:02 a.m. UTC | #4 
On 3/26/21 9:26 AM, Janosch Frank wrote:
> On 3/25/21 10:39 AM, Pierre Morel wrote:
>> Some tests require to disable a subchannel.
>> Let's implement the css_disable() function.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 
> Acked-by: Janosch Frank <frankja@linux.ibm.com>

thanks,
Pierre
Thomas Huth March 29, 2021, 8 a.m. UTC | #5 
On 25/03/2021 10.39, Pierre Morel wrote:
> Some tests require to disable a subchannel.
> Let's implement the css_disable() function.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> ---
>   lib/s390x/css.h     |  1 +
>   lib/s390x/css_lib.c | 67 +++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 68 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..f5c4f37 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -186,6 +186,73 @@ 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:

I have to saythat I really dislike writing loops with gotos if it can be 
avoided easily. What about:

for (retry_count = 0; retry_count < MAX_ENABLE_RETRIES; retry_count++) ?

(and maybe rename that variable to "retries" to keep it short?)

> +	/* 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 the subchannel is status pending or if a function is in progress,
> +	 * we consider both cases as errors.
> +	 */
> +	if (cc) {
> +		report_info("msch: sch %08x failed with cc=%d", schid, cc);
> +		return cc;
> +	}
> +
> +	/* Read the SCHIB again to verify the enablement */

"verify the disablement" ?

> +	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) {
> +		/* the hardware was not ready, give it some time */
> +		mdelay(10);
> +		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
> 

  Thomas
Pierre Morel March 29, 2021, 12:33 p.m. UTC | #6 
On 3/29/21 10:00 AM, Thomas Huth wrote:
> On 25/03/2021 10.39, Pierre Morel wrote:
>> Some tests require to disable a subchannel.
>> Let's implement the css_disable() function.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>>   lib/s390x/css.h     |  1 +
>>   lib/s390x/css_lib.c | 67 +++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 68 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..f5c4f37 100644
>> --- a/lib/s390x/css_lib.c
>> +++ b/lib/s390x/css_lib.c
>> @@ -186,6 +186,73 @@ 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:
> 
> I have to saythat I really dislike writing loops with gotos if it can be 
> avoided easily. What about:
> 
> for (retry_count = 0; retry_count < MAX_ENABLE_RETRIES; retry_count++) ?
> 
> (and maybe rename that variable to "retries" to keep it short?)

hum, you already said that.
Sorry, I forgot and duplicated css_enable()

done.


...


>> +    /* Read the SCHIB again to verify the enablement */
> 
> "verify the disablement" ?

:) yes

> 
>> +    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) {
>> +        /* the hardware was not ready, give it some time */
>> +        mdelay(10);
>> +        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
>>
> 
>   Thomas
> 

Thanks,
Pierre
diff mbox series

Patch

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..f5c4f37 100644
--- a/lib/s390x/css_lib.c
+++ b/lib/s390x/css_lib.c
@@ -186,6 +186,73 @@  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 the subchannel is status pending or if a function is in progress,
+	 * we consider both cases as errors.
+	 */
+	if (cc) {
+		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) {
+		/* the hardware was not ready, give it some time */
+		mdelay(10);
+		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