diff mbox series

[v3] powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible

Message ID 20210508043642.114076-1-vaibhav@linux.ibm.com (mailing list archive)
State New
Headers show
Series [v3] powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible | expand

Commit Message

Vaibhav Jain May 8, 2021, 4:36 a.m. UTC
Currently drc_pmem_qeury_stats() generates a dev_err in case
"Enable Performance Information Collection" feature is disabled from
HMC or performance stats are not available for an nvdimm. The error is
of the form below:

papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Failed to query
	 performance stats, Err:-10

This error message confuses users as it implies a possible problem
with the nvdimm even though its due to a disabled/unavailable
feature. We fix this by explicitly handling the H_AUTHORITY and
H_UNSUPPORTED errors from the H_SCM_PERFORMANCE_STATS hcall.

In case of H_AUTHORITY error an info message is logged instead of an
error, saying that "Permission denied while accessing performance
stats" and an EPERM error is returned back.

In case of H_UNSUPPORTED error we return a EOPNOTSUPP error back from
drc_pmem_query_stats() indicating that performance stats-query
operation is not supported on this nvdimm.

Fixes: 2d02bf835e57('powerpc/papr_scm: Fetch nvdimm performance stats from PHYP')
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
Changelog

v3:
* Return EOPNOTSUPP error in case of H_UNSUPPORTED [ Ira ]
* Return EPERM in case of H_AUTHORITY [ Ira ]
* Updated patch description

v2:
* Updated the message logged in case of H_AUTHORITY error [ Ira ]
* Switched from dev_warn to dev_info in case of H_AUTHORITY error.
* Instead of -EPERM return -EACCESS for H_AUTHORITY error.
* Added explicit handling of H_UNSUPPORTED error.
---
 arch/powerpc/platforms/pseries/papr_scm.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Ira Weiny May 8, 2021, 3:11 p.m. UTC | #1
On Sat, May 08, 2021 at 10:06:42AM +0530, Vaibhav Jain wrote:
> Currently drc_pmem_qeury_stats() generates a dev_err in case
> "Enable Performance Information Collection" feature is disabled from
> HMC or performance stats are not available for an nvdimm. The error is
> of the form below:
> 
> papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Failed to query
> 	 performance stats, Err:-10
> 
> This error message confuses users as it implies a possible problem
> with the nvdimm even though its due to a disabled/unavailable
> feature. We fix this by explicitly handling the H_AUTHORITY and
> H_UNSUPPORTED errors from the H_SCM_PERFORMANCE_STATS hcall.
> 
> In case of H_AUTHORITY error an info message is logged instead of an
> error, saying that "Permission denied while accessing performance
> stats" and an EPERM error is returned back.
> 
> In case of H_UNSUPPORTED error we return a EOPNOTSUPP error back from
> drc_pmem_query_stats() indicating that performance stats-query
> operation is not supported on this nvdimm.
> 
> Fixes: 2d02bf835e57('powerpc/papr_scm: Fetch nvdimm performance stats from PHYP')
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
> Changelog
> 
> v3:
> * Return EOPNOTSUPP error in case of H_UNSUPPORTED [ Ira ]
> * Return EPERM in case of H_AUTHORITY [ Ira ]
> * Updated patch description
> 
> v2:
> * Updated the message logged in case of H_AUTHORITY error [ Ira ]
> * Switched from dev_warn to dev_info in case of H_AUTHORITY error.
> * Instead of -EPERM return -EACCESS for H_AUTHORITY error.
> * Added explicit handling of H_UNSUPPORTED error.
> ---
>  arch/powerpc/platforms/pseries/papr_scm.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
> index ef26fe40efb0..e2b69cc3beaf 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -310,6 +310,13 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
>  		dev_err(&p->pdev->dev,
>  			"Unknown performance stats, Err:0x%016lX\n", ret[0]);
>  		return -ENOENT;
> +	} else if (rc == H_AUTHORITY) {
> +		dev_info(&p->pdev->dev,
> +			 "Permission denied while accessing performance stats");
> +		return -EPERM;
> +	} else if (rc == H_UNSUPPORTED) {
> +		dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
> +		return -EOPNOTSUPP;
>  	} else if (rc != H_SUCCESS) {
>  		dev_err(&p->pdev->dev,
>  			"Failed to query performance stats, Err:%lld\n", rc);
> -- 
> 2.31.1
>
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index ef26fe40efb0..e2b69cc3beaf 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -310,6 +310,13 @@  static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
 		dev_err(&p->pdev->dev,
 			"Unknown performance stats, Err:0x%016lX\n", ret[0]);
 		return -ENOENT;
+	} else if (rc == H_AUTHORITY) {
+		dev_info(&p->pdev->dev,
+			 "Permission denied while accessing performance stats");
+		return -EPERM;
+	} else if (rc == H_UNSUPPORTED) {
+		dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
+		return -EOPNOTSUPP;
 	} else if (rc != H_SUCCESS) {
 		dev_err(&p->pdev->dev,
 			"Failed to query performance stats, Err:%lld\n", rc);