powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric

We add support for reporting 'fuel-gauge' NVDIMM metric via
PAPR_PDSM_HEALTH pdsm payload. 'fuel-gauge' metric indicates the usage
life remaining of a papr-scm compatible NVDIMM. PHYP exposes this
metric via the H_SCM_PERFORMANCE_STATS.

The metric value is returned from the pdsm by extending the return
payload 'struct nd_papr_pdsm_health' without breaking the ABI. A new
field 'dimm_fuel_gauge' to hold the metric value is introduced at the
end of the payload struct and its presence is indicated by by
extension flag PDSM_DIMM_HEALTH_RUN_GAUGE_VALID.

The patch introduces a new function papr_pdsm_fuel_gauge() that is
called from papr_pdsm_health(). If fetching NVDIMM performance stats
is supported then 'papr_pdsm_fuel_gauge()' allocated an output buffer
large enough to hold the performance stat and passes it to
drc_pmem_query_stats() that issues the HCALL to PHYP. The return value
of the stat is then populated in the 'struct
nd_papr_pdsm_health.dimm_fuel_gauge' field with extension flag
'PDSM_DIMM_HEALTH_RUN_GAUGE_VALID' set in 'struct
nd_papr_pdsm_health.extension_flags'

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200731064153.182203-3-vaibhav@linux.ibm.com
This commit is contained in:
Vaibhav Jain
2020-07-31 12:11:53 +05:30
committed by Michael Ellerman
parent 2d02bf835e
commit af0870c4e7
2 changed files with 58 additions and 0 deletions
@@ -72,6 +72,11 @@
#define PAPR_PDSM_DIMM_CRITICAL 2
#define PAPR_PDSM_DIMM_FATAL 3
/* struct nd_papr_pdsm_health.extension_flags field flags */
/* Indicate that the 'dimm_fuel_gauge' field is valid */
#define PDSM_DIMM_HEALTH_RUN_GAUGE_VALID 1
/*
* Struct exchanged between kernel & ndctl in for PAPR_PDSM_HEALTH
* Various flags indicate the health status of the dimm.
@@ -84,6 +89,7 @@
* dimm_locked : Contents of the dimm cant be modified until CEC reboot
* dimm_encrypted : Contents of dimm are encrypted.
* dimm_health : Dimm health indicator. One of PAPR_PDSM_DIMM_XXXX
* dimm_fuel_gauge : Life remaining of DIMM as a percentage from 0-100
*/
struct nd_papr_pdsm_health {
union {
@@ -96,6 +102,9 @@ struct nd_papr_pdsm_health {
__u8 dimm_locked;
__u8 dimm_encrypted;
__u16 dimm_health;
/* Extension flag PDSM_DIMM_HEALTH_RUN_GAUGE_VALID */
__u16 dimm_fuel_gauge;
};
__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
};