From af0870c4e75655b1931d0a5ffde2f448a2794362 Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Fri, 31 Jul 2020 12:11:53 +0530 Subject: [PATCH] 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 Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200731064153.182203-3-vaibhav@linux.ibm.com --- arch/powerpc/include/uapi/asm/papr_pdsm.h | 9 +++++ arch/powerpc/platforms/pseries/papr_scm.c | 49 +++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/arch/powerpc/include/uapi/asm/papr_pdsm.h b/arch/powerpc/include/uapi/asm/papr_pdsm.h index 9ccecc1d6840..50ef95e2f5b1 100644 --- a/arch/powerpc/include/uapi/asm/papr_pdsm.h +++ b/arch/powerpc/include/uapi/asm/papr_pdsm.h @@ -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]; }; diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index f37f3f70007d..f439f0dfea7d 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -518,6 +518,51 @@ static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf, return 0; } +static int papr_pdsm_fuel_gauge(struct papr_scm_priv *p, + union nd_pdsm_payload *payload) +{ + int rc, size; + u64 statval; + struct papr_scm_perf_stat *stat; + struct papr_scm_perf_stats *stats; + + /* Silently fail if fetching performance metrics isn't supported */ + if (!p->stat_buffer_len) + return 0; + + /* Allocate request buffer enough to hold single performance stat */ + size = sizeof(struct papr_scm_perf_stats) + + sizeof(struct papr_scm_perf_stat); + + stats = kzalloc(size, GFP_KERNEL); + if (!stats) + return -ENOMEM; + + stat = &stats->scm_statistic[0]; + memcpy(&stat->stat_id, "MemLife ", sizeof(stat->stat_id)); + stat->stat_val = 0; + + /* Fetch the fuel gauge and populate it in payload */ + rc = drc_pmem_query_stats(p, stats, 1); + if (rc < 0) { + dev_dbg(&p->pdev->dev, "Err(%d) fetching fuel gauge\n", rc); + goto free_stats; + } + + statval = be64_to_cpu(stat->stat_val); + dev_dbg(&p->pdev->dev, + "Fetched fuel-gauge %llu", statval); + payload->health.extension_flags |= + PDSM_DIMM_HEALTH_RUN_GAUGE_VALID; + payload->health.dimm_fuel_gauge = statval; + + rc = sizeof(struct nd_papr_pdsm_health); + +free_stats: + kfree(stats); + return rc; +} + /* Fetch the DIMM health info and populate it in provided package. */ static int papr_pdsm_health(struct papr_scm_priv *p, union nd_pdsm_payload *payload) @@ -558,6 +603,10 @@ static int papr_pdsm_health(struct papr_scm_priv *p, /* struct populated hence can release the mutex now */ mutex_unlock(&p->health_mutex); + + /* Populate the fuel gauge meter in the payload */ + papr_pdsm_fuel_gauge(p, payload); + rc = sizeof(struct nd_papr_pdsm_health); out: