Re: [PATCH 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
Thanks for reviewing this patch Ira,
My responses below:
Ira Weiny writes:
[snip]
>> +static int papr_pdsm_fuel_gauge(struct papr_scm_priv *p,
>> +union nd_pdsm_payload *payload)
>> +{
>> +int rc, size;
>> +struct papr_scm_perf_stat *stat;
>> +struct papr_scm_perf_stats *stats;
>> +
>> +/* Silently fail if fetching performance metrics isn't supported */
>> +if (!p->len_stat_buffer)
>> +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 = >scm_statistic[0];
>> +memcpy(>statistic_id, "MemLife ", sizeof(stat->statistic_id));
>> +stat->statistic_value = 0;
>> +
>> +/* Fetch the fuel gauge and populate it in payload */
>> +rc = drc_pmem_query_stats(p, stats, size, 1, NULL);
>> +if (!rc) {
>
> Always best to except the error case...
>
> if (rc) {
> ... print debuging from below...
> goto free_stats;
> }
>
Sure, I don't feel strongly about it. Will update this in v2.
>> +dev_dbg(>pdev->dev,
>> +"Fetched fuel-gauge %llu", stat->statistic_value);
>> +payload->health.extension_flags |=
>> +PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
>> +payload->health.dimm_fuel_gauge = stat->statistic_value;
>> +
>> +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)
>> @@ -546,6 +585,14 @@ static int papr_pdsm_health(struct papr_scm_priv *p,
>>
>> /* struct populated hence can release the mutex now */
>> mutex_unlock(>health_mutex);
>> +
>> +/* Populate the fuel gauge meter in the payload */
>> +rc = papr_pdsm_fuel_gauge(p, payload);
>> +
>> +/* Error fetching fuel gauge is not fatal */
>> +if (rc < 0)
>> +dev_dbg(>pdev->dev, "Err(%d) fetching fuel gauge\n", rc);
>
> Why even return an error? Just have *_fuel_guage() the print the debugging
> and
> return void.
>
papr_pdsm_fuel_gauge uses the same signature as other PDSM service
functions as described in pdsm_cmd_desc.service callback. Hence designed
the function signature as such.
>> +
>> rc = sizeof(struct nd_papr_pdsm_health);
>
> You just override rc here anyway...
>
> Ira
>
>>
>> out:
>> --
>> 2.26.2
>> ___
>> Linux-nvdimm mailing list -- linux-nvd...@lists.01.org
>> To unsubscribe send an email to linux-nvdimm-le...@lists.01.org
--
Cheers
~ Vaibhav
Re: [PATCH 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
On Mon, Jun 22, 2020 at 09:54:51AM +0530, Vaibhav Jain wrote:
> 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
> ---
> arch/powerpc/include/uapi/asm/papr_pdsm.h | 9 +
> arch/powerpc/platforms/pseries/papr_scm.c | 47 +++
> 2 files changed, 56 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_
> + * 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 cb3f9acc325b..39527cd38d9c 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -506,6 +506,45 @@ 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;
> + struct papr_scm_perf_stat *stat;
> + struct papr_scm_perf_stats *stats;
> +
> + /* Silently fail if fetching performance metrics isn't supported */
> + if (!p->len_stat_buffer)
> + 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 = >scm_statistic[0];
> + memcpy(>statistic_id, "MemLife ", sizeof(stat->statistic_id));
> + stat->statistic_value = 0;
> +
> + /* Fetch the fuel gauge and populate it in payload */
> + rc = drc_pmem_query_stats(p, stats, size, 1, NULL);
> + if (!rc) {
Always best to except the error case...
if (rc) {
... print debuging from below...
goto free_stats;
}
> + dev_dbg(>pdev->dev,
> + "Fetched fuel-gauge %llu", stat->statistic_value);
> + payload->health.extension_flags |=
> + PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
> + payload->health.dimm_fuel_gauge = stat->statistic_value;
> +
> + 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)
> @@ -546,6 +585,14 @@ static int
[PATCH 2/2] 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
---
arch/powerpc/include/uapi/asm/papr_pdsm.h | 9 +
arch/powerpc/platforms/pseries/papr_scm.c | 47 +++
2 files changed, 56 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_
+ * 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 cb3f9acc325b..39527cd38d9c 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -506,6 +506,45 @@ 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;
+ struct papr_scm_perf_stat *stat;
+ struct papr_scm_perf_stats *stats;
+
+ /* Silently fail if fetching performance metrics isn't supported */
+ if (!p->len_stat_buffer)
+ 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 = >scm_statistic[0];
+ memcpy(>statistic_id, "MemLife ", sizeof(stat->statistic_id));
+ stat->statistic_value = 0;
+
+ /* Fetch the fuel gauge and populate it in payload */
+ rc = drc_pmem_query_stats(p, stats, size, 1, NULL);
+ if (!rc) {
+ dev_dbg(>pdev->dev,
+ "Fetched fuel-gauge %llu", stat->statistic_value);
+ payload->health.extension_flags |=
+ PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
+ payload->health.dimm_fuel_gauge = stat->statistic_value;
+
+ rc = sizeof(struct nd_papr_pdsm_health);
+ }
+
+ 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)
@@ -546,6 +585,14 @@ static int papr_pdsm_health(struct papr_scm_priv *p,
/* struct populated hence can release the mutex now */
mutex_unlock(>health_mutex);
+
+ /* Populate the fuel gauge meter in the payload */
+ rc = papr_pdsm_fuel_gauge(p, payload);
+
+ /* Error fetching fuel gauge is not fatal */
+ if (rc < 0)
+ dev_dbg(>pdev->dev, "Err(%d) fetching fuel gauge\n", rc);
+
rc =
