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(a)linux.ibm.com&gt; --- 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