* [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric
@ 2020-07-31 6:41 Vaibhav Jain
2020-07-31 6:41 ` [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP Vaibhav Jain
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Vaibhav Jain @ 2020-07-31 6:41 UTC (permalink / raw)
To: linuxppc-dev, linux-nvdimm
Cc: Santosh Sivaraj, Oliver O'Halloran, Aneesh Kumar K . V,
Vaibhav Jain, Dan Williams, Ira Weiny
Changes since v3[1]:
* Fixed a rebase issue pointed out by Aneesh in first patch in the series.
[1] https://lore.kernel.org/linux-nvdimm/20200730121303.134230-1-vaibhav@linux.ibm.com
---
This small patchset implements kernel side support for reporting
'life_used_percentage' metric in NDCTL with dimm health output for
papr-scm NVDIMMs. With corresponding NDCTL side changes output for
should be like:
$ sudo ndctl list -DH
[
{
"dev":"nmem0",
"health":{
"health_state":"ok",
"life_used_percentage":0,
"shutdown_state":"clean"
}
}
]
PHYP supports H_SCM_PERFORMANCE_STATS hcall through which an LPAR can
fetch various performance stats including 'fuel_gauge' percentage for
an NVDIMM. 'fuel_gauge' metric indicates the usable life remaining of
an NVDIMM expressed as percentage and 'life_used_percentage' can be
calculated as 'life_used_percentage = 100 - fuel_gauge'.
Structure of the patchset
=========================
First patch implements necessary scaffolding needed to issue the
H_SCM_PERFORMANCE_STATS hcall and fetch performance stats
catalogue. The patch also implements support for 'perf_stats' sysfs
attribute to report the full catalogue of supported performance stats
by PHYP.
Second and final patch implements support for sending this value to
libndctl by extending the PAPR_PDSM_HEALTH pdsm payload to add a new
field named 'dimm_fuel_gauge' to it.
Vaibhav Jain (2):
powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
Documentation/ABI/testing/sysfs-bus-papr-pmem | 27 +++
arch/powerpc/include/uapi/asm/papr_pdsm.h | 9 +
arch/powerpc/platforms/pseries/papr_scm.c | 199 ++++++++++++++++++
3 files changed, 235 insertions(+)
--
2.26.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
2020-07-31 6:41 [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric Vaibhav Jain
@ 2020-07-31 6:41 ` Vaibhav Jain
2020-07-31 7:12 ` Aneesh Kumar K.V
2020-07-31 6:41 ` [PATCH v4 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric Vaibhav Jain
2020-08-02 13:35 ` [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric Michael Ellerman
2 siblings, 1 reply; 6+ messages in thread
From: Vaibhav Jain @ 2020-07-31 6:41 UTC (permalink / raw)
To: linuxppc-dev, linux-nvdimm
Cc: Santosh Sivaraj, Oliver O'Halloran, Aneesh Kumar K . V,
Vaibhav Jain, Dan Williams, Ira Weiny
Update papr_scm.c to query dimm performance statistics from PHYP via
H_SCM_PERFORMANCE_STATS hcall and export them to user-space as PAPR
specific NVDIMM attribute 'perf_stats' in sysfs. The patch also
provide a sysfs ABI documentation for the stats being reported and
their meanings.
During NVDIMM probe time in papr_scm_nvdimm_init() a special variant
of H_SCM_PERFORMANCE_STATS hcall is issued to check if collection of
performance statistics is supported or not. If successful then a PHYP
returns a maximum possible buffer length needed to read all
performance stats. This returned value is stored in a per-nvdimm
attribute 'stat_buffer_len'.
The layout of request buffer for reading NVDIMM performance stats from
PHYP is defined in 'struct papr_scm_perf_stats' and 'struct
papr_scm_perf_stat'. These structs are used in newly introduced
drc_pmem_query_stats() that issues the H_SCM_PERFORMANCE_STATS hcall.
The sysfs access function perf_stats_show() uses value
'stat_buffer_len' to allocate a buffer large enough to hold all
possible NVDIMM performance stats and passes it to
drc_pmem_query_stats() to populate. Finally statistics reported in the
buffer are formatted into the sysfs access function output buffer.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
Changelog:
v4:
* Fixed a build issue with this patch by moving a hunk from second
patch in series to this patch. [ Aneesh ]
v3:
* Updated drc_pmem_query_stats() to not require 'buff_size' and 'out'
args to the function. Instead 'buff_size' is calculated from
'num_stats' and instead of populating 'R4' in arg 'out' the value is
returned from the function in case 'R4' represents
'max-buffer-size'.
Resend:
None
v2:
* Updated 'struct papr_scm_perf_stats' and 'struct papr_scm_perf_stat'
to use big-endian types. [ Aneesh ]
* s/len_stat_buffer/stat_buffer_len/ [ Aneesh ]
* s/statistics_id/stat_id/ , s/statistics_val/stat_val/ [ Aneesh ]
* Conversion from Big endian to cpu endian happens later rather than
just after its fetched from PHYP.
* Changed a log statement to unambiguously report dimm performance
stats are not available for the given nvdimm [ Ira ]
* Restructed some code to handle error case first [ Ira ]
---
Documentation/ABI/testing/sysfs-bus-papr-pmem | 27 ++++
arch/powerpc/platforms/pseries/papr_scm.c | 150 ++++++++++++++++++
2 files changed, 177 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-papr-pmem b/Documentation/ABI/testing/sysfs-bus-papr-pmem
index 5b10d036a8d4..c1a67275c43f 100644
--- a/Documentation/ABI/testing/sysfs-bus-papr-pmem
+++ b/Documentation/ABI/testing/sysfs-bus-papr-pmem
@@ -25,3 +25,30 @@ Description:
NVDIMM have been scrubbed.
* "locked" : Indicating that NVDIMM contents cant
be modified until next power cycle.
+
+What: /sys/bus/nd/devices/nmemX/papr/perf_stats
+Date: May, 2020
+KernelVersion: v5.9
+Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-nvdimm@lists.01.org,
+Description:
+ (RO) Report various performance stats related to papr-scm NVDIMM
+ device. Each stat is reported on a new line with each line
+ composed of a stat-identifier followed by it value. Below are
+ currently known dimm performance stats which are reported:
+
+ * "CtlResCt" : Controller Reset Count
+ * "CtlResTm" : Controller Reset Elapsed Time
+ * "PonSecs " : Power-on Seconds
+ * "MemLife " : Life Remaining
+ * "CritRscU" : Critical Resource Utilization
+ * "HostLCnt" : Host Load Count
+ * "HostSCnt" : Host Store Count
+ * "HostSDur" : Host Store Duration
+ * "HostLDur" : Host Load Duration
+ * "MedRCnt " : Media Read Count
+ * "MedWCnt " : Media Write Count
+ * "MedRDur " : Media Read Duration
+ * "MedWDur " : Media Write Duration
+ * "CchRHCnt" : Cache Read Hit Count
+ * "CchWHCnt" : Cache Write Hit Count
+ * "FastWCnt" : Fast Write Count
\ No newline at end of file
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 3d1235a76ba9..f37f3f70007d 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -64,6 +64,26 @@
PAPR_PMEM_HEALTH_FATAL | \
PAPR_PMEM_HEALTH_UNHEALTHY)
+#define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
+#define PAPR_SCM_PERF_STATS_VERSION 0x1
+
+/* Struct holding a single performance metric */
+struct papr_scm_perf_stat {
+ u8 stat_id[8];
+ __be64 stat_val;
+} __packed;
+
+/* Struct exchanged between kernel and PHYP for fetching drc perf stats */
+struct papr_scm_perf_stats {
+ u8 eye_catcher[8];
+ /* Should be PAPR_SCM_PERF_STATS_VERSION */
+ __be32 stats_version;
+ /* Number of stats following */
+ __be32 num_statistics;
+ /* zero or more performance matrics */
+ struct papr_scm_perf_stat scm_statistic[];
+} __packed;
+
/* private struct associated with each region */
struct papr_scm_priv {
struct platform_device *pdev;
@@ -92,6 +112,9 @@ struct papr_scm_priv {
/* Health information for the dimm */
u64 health_bitmap;
+
+ /* length of the stat buffer as expected by phyp */
+ size_t stat_buffer_len;
};
static LIST_HEAD(papr_nd_regions);
@@ -200,6 +223,79 @@ static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
return drc_pmem_bind(p);
}
+/*
+ * Query the Dimm performance stats from PHYP and copy them (if returned) to
+ * provided struct papr_scm_perf_stats instance 'stats' that can hold atleast
+ * (num_stats + header) bytes.
+ * - If buff_stats == NULL the return value is the size in byes of the buffer
+ * needed to hold all supported performance-statistics.
+ * - If buff_stats != NULL and num_stats == 0 then we copy all known
+ * performance-statistics to 'buff_stat' and expect to be large enough to
+ * hold them.
+ * - if buff_stats != NULL and num_stats > 0 then copy the requested
+ * performance-statistics to buff_stats.
+ */
+static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
+ struct papr_scm_perf_stats *buff_stats,
+ unsigned int num_stats)
+{
+ unsigned long ret[PLPAR_HCALL_BUFSIZE];
+ size_t size;
+ s64 rc;
+
+ /* Setup the out buffer */
+ if (buff_stats) {
+ memcpy(buff_stats->eye_catcher,
+ PAPR_SCM_PERF_STATS_EYECATCHER, 8);
+ buff_stats->stats_version =
+ cpu_to_be32(PAPR_SCM_PERF_STATS_VERSION);
+ buff_stats->num_statistics =
+ cpu_to_be32(num_stats);
+
+ /*
+ * Calculate the buffer size based on num-stats provided
+ * or use the prefetched max buffer length
+ */
+ if (num_stats)
+ /* Calculate size from the num_stats */
+ size = sizeof(struct papr_scm_perf_stats) +
+ num_stats * sizeof(struct papr_scm_perf_stat);
+ else
+ size = p->stat_buffer_len;
+ } else {
+ /* In case of no out buffer ignore the size */
+ size = 0;
+ }
+
+ /* Do the HCALL asking PHYP for info */
+ rc = plpar_hcall(H_SCM_PERFORMANCE_STATS, ret, p->drc_index,
+ buff_stats ? virt_to_phys(buff_stats) : 0,
+ size);
+
+ /* Check if the error was due to an unknown stat-id */
+ if (rc == H_PARTIAL) {
+ dev_err(&p->pdev->dev,
+ "Unknown performance stats, Err:0x%016lX\n", ret[0]);
+ return -ENOENT;
+ } else if (rc != H_SUCCESS) {
+ dev_err(&p->pdev->dev,
+ "Failed to query performance stats, Err:%lld\n", rc);
+ return -EIO;
+
+ } else if (!size) {
+ /* Handle case where stat buffer size was requested */
+ dev_dbg(&p->pdev->dev,
+ "Performance stats size %ld\n", ret[0]);
+ return ret[0];
+ }
+
+ /* Successfully fetched the requested stats from phyp */
+ dev_dbg(&p->pdev->dev,
+ "Performance stats returned %d stats\n",
+ be32_to_cpu(buff_stats->num_statistics));
+ return 0;
+}
+
/*
* Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
* health information.
@@ -637,6 +733,48 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
return 0;
}
+static ssize_t perf_stats_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int index, rc;
+ struct seq_buf s;
+ struct papr_scm_perf_stat *stat;
+ struct papr_scm_perf_stats *stats;
+ struct nvdimm *dimm = to_nvdimm(dev);
+ struct papr_scm_priv *p = nvdimm_provider_data(dimm);
+
+ if (!p->stat_buffer_len)
+ return -ENOENT;
+
+ /* Allocate the buffer for phyp where stats are written */
+ stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
+ if (!stats)
+ return -ENOMEM;
+
+ /* Ask phyp to return all dimm perf stats */
+ rc = drc_pmem_query_stats(p, stats, 0);
+ if (rc)
+ goto free_stats;
+ /*
+ * Go through the returned output buffer and print stats and
+ * values. Since stat_id is essentially a char string of
+ * 8 bytes, simply use the string format specifier to print it.
+ */
+ seq_buf_init(&s, buf, PAGE_SIZE);
+ for (index = 0, stat = stats->scm_statistic;
+ index < be32_to_cpu(stats->num_statistics);
+ ++index, ++stat) {
+ seq_buf_printf(&s, "%.8s = 0x%016llX\n",
+ stat->stat_id,
+ be64_to_cpu(stat->stat_val));
+ }
+
+free_stats:
+ kfree(stats);
+ return rc ? rc : seq_buf_used(&s);
+}
+DEVICE_ATTR_RO(perf_stats);
+
static ssize_t flags_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -682,6 +820,7 @@ DEVICE_ATTR_RO(flags);
/* papr_scm specific dimm attributes */
static struct attribute *papr_nd_attributes[] = {
&dev_attr_flags.attr,
+ &dev_attr_perf_stats.attr,
NULL,
};
@@ -702,6 +841,7 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
struct nd_region_desc ndr_desc;
unsigned long dimm_flags;
int target_nid, online_nid;
+ ssize_t stat_size;
p->bus_desc.ndctl = papr_scm_ndctl;
p->bus_desc.module = THIS_MODULE;
@@ -769,6 +909,16 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
list_add_tail(&p->region_list, &papr_nd_regions);
mutex_unlock(&papr_ndr_lock);
+ /* Try retriving the stat buffer and see if its supported */
+ stat_size = drc_pmem_query_stats(p, NULL, 0);
+ if (stat_size > 0) {
+ p->stat_buffer_len = stat_size;
+ dev_dbg(&p->pdev->dev, "Max perf-stat size %lu-bytes\n",
+ p->stat_buffer_len);
+ } else {
+ dev_info(&p->pdev->dev, "Dimm performance stats unavailable\n");
+ }
+
return 0;
err: nvdimm_bus_unregister(p->bus);
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
2020-07-31 6:41 [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric Vaibhav Jain
2020-07-31 6:41 ` [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP Vaibhav Jain
@ 2020-07-31 6:41 ` Vaibhav Jain
2020-07-31 7:14 ` Aneesh Kumar K.V
2020-08-02 13:35 ` [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric Michael Ellerman
2 siblings, 1 reply; 6+ messages in thread
From: Vaibhav Jain @ 2020-07-31 6:41 UTC (permalink / raw)
To: linuxppc-dev, linux-nvdimm
Cc: Santosh Sivaraj, Oliver O'Halloran, Aneesh Kumar K . V,
Vaibhav Jain, Dan Williams, Ira Weiny
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>
---
Changelog:
v4:
* Moved a hunk from this patch to previous patch in the series.
[ Aneesh ]
v3:
* Updated papr_pdsm_fuel_guage() to use the updated
drc_pmem_query_stats() function.
Resend:
None
v2:
* Restructure code in papr_pdsm_fuel_gauge() to handle error case
first [ Ira ]
* Ignore the return value of papr_pdsm_fuel_gauge() in
papr_psdm_health() [ Ira ]
---
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:
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
2020-07-31 6:41 ` [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP Vaibhav Jain
@ 2020-07-31 7:12 ` Aneesh Kumar K.V
0 siblings, 0 replies; 6+ messages in thread
From: Aneesh Kumar K.V @ 2020-07-31 7:12 UTC (permalink / raw)
To: Vaibhav Jain, linuxppc-dev, linux-nvdimm
Cc: Santosh Sivaraj, Oliver O'Halloran, Vaibhav Jain,
Dan Williams, Ira Weiny
Vaibhav Jain <vaibhav@linux.ibm.com> writes:
> Update papr_scm.c to query dimm performance statistics from PHYP via
> H_SCM_PERFORMANCE_STATS hcall and export them to user-space as PAPR
> specific NVDIMM attribute 'perf_stats' in sysfs. The patch also
> provide a sysfs ABI documentation for the stats being reported and
> their meanings.
>
> During NVDIMM probe time in papr_scm_nvdimm_init() a special variant
> of H_SCM_PERFORMANCE_STATS hcall is issued to check if collection of
> performance statistics is supported or not. If successful then a PHYP
> returns a maximum possible buffer length needed to read all
> performance stats. This returned value is stored in a per-nvdimm
> attribute 'stat_buffer_len'.
>
> The layout of request buffer for reading NVDIMM performance stats from
> PHYP is defined in 'struct papr_scm_perf_stats' and 'struct
> papr_scm_perf_stat'. These structs are used in newly introduced
> drc_pmem_query_stats() that issues the H_SCM_PERFORMANCE_STATS hcall.
>
> The sysfs access function perf_stats_show() uses value
> 'stat_buffer_len' to allocate a buffer large enough to hold all
> possible NVDIMM performance stats and passes it to
> drc_pmem_query_stats() to populate. Finally statistics reported in the
> buffer are formatted into the sysfs access function output buffer.
>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---
> Changelog:
>
> v4:
> * Fixed a build issue with this patch by moving a hunk from second
> patch in series to this patch. [ Aneesh ]
>
> v3:
> * Updated drc_pmem_query_stats() to not require 'buff_size' and 'out'
> args to the function. Instead 'buff_size' is calculated from
> 'num_stats' and instead of populating 'R4' in arg 'out' the value is
> returned from the function in case 'R4' represents
> 'max-buffer-size'.
>
> Resend:
> None
>
> v2:
> * Updated 'struct papr_scm_perf_stats' and 'struct papr_scm_perf_stat'
> to use big-endian types. [ Aneesh ]
> * s/len_stat_buffer/stat_buffer_len/ [ Aneesh ]
> * s/statistics_id/stat_id/ , s/statistics_val/stat_val/ [ Aneesh ]
> * Conversion from Big endian to cpu endian happens later rather than
> just after its fetched from PHYP.
> * Changed a log statement to unambiguously report dimm performance
> stats are not available for the given nvdimm [ Ira ]
> * Restructed some code to handle error case first [ Ira ]
> ---
> Documentation/ABI/testing/sysfs-bus-papr-pmem | 27 ++++
> arch/powerpc/platforms/pseries/papr_scm.c | 150 ++++++++++++++++++
> 2 files changed, 177 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-papr-pmem b/Documentation/ABI/testing/sysfs-bus-papr-pmem
> index 5b10d036a8d4..c1a67275c43f 100644
> --- a/Documentation/ABI/testing/sysfs-bus-papr-pmem
> +++ b/Documentation/ABI/testing/sysfs-bus-papr-pmem
> @@ -25,3 +25,30 @@ Description:
> NVDIMM have been scrubbed.
> * "locked" : Indicating that NVDIMM contents cant
> be modified until next power cycle.
> +
> +What: /sys/bus/nd/devices/nmemX/papr/perf_stats
> +Date: May, 2020
> +KernelVersion: v5.9
> +Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-nvdimm@lists.01.org,
> +Description:
> + (RO) Report various performance stats related to papr-scm NVDIMM
> + device. Each stat is reported on a new line with each line
> + composed of a stat-identifier followed by it value. Below are
> + currently known dimm performance stats which are reported:
> +
> + * "CtlResCt" : Controller Reset Count
> + * "CtlResTm" : Controller Reset Elapsed Time
> + * "PonSecs " : Power-on Seconds
> + * "MemLife " : Life Remaining
> + * "CritRscU" : Critical Resource Utilization
> + * "HostLCnt" : Host Load Count
> + * "HostSCnt" : Host Store Count
> + * "HostSDur" : Host Store Duration
> + * "HostLDur" : Host Load Duration
> + * "MedRCnt " : Media Read Count
> + * "MedWCnt " : Media Write Count
> + * "MedRDur " : Media Read Duration
> + * "MedWDur " : Media Write Duration
> + * "CchRHCnt" : Cache Read Hit Count
> + * "CchWHCnt" : Cache Write Hit Count
> + * "FastWCnt" : Fast Write Count
> \ No newline at end of file
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
> index 3d1235a76ba9..f37f3f70007d 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -64,6 +64,26 @@
> PAPR_PMEM_HEALTH_FATAL | \
> PAPR_PMEM_HEALTH_UNHEALTHY)
>
> +#define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
> +#define PAPR_SCM_PERF_STATS_VERSION 0x1
> +
> +/* Struct holding a single performance metric */
> +struct papr_scm_perf_stat {
> + u8 stat_id[8];
> + __be64 stat_val;
> +} __packed;
> +
> +/* Struct exchanged between kernel and PHYP for fetching drc perf stats */
> +struct papr_scm_perf_stats {
> + u8 eye_catcher[8];
> + /* Should be PAPR_SCM_PERF_STATS_VERSION */
> + __be32 stats_version;
> + /* Number of stats following */
> + __be32 num_statistics;
> + /* zero or more performance matrics */
> + struct papr_scm_perf_stat scm_statistic[];
> +} __packed;
> +
> /* private struct associated with each region */
> struct papr_scm_priv {
> struct platform_device *pdev;
> @@ -92,6 +112,9 @@ struct papr_scm_priv {
>
> /* Health information for the dimm */
> u64 health_bitmap;
> +
> + /* length of the stat buffer as expected by phyp */
> + size_t stat_buffer_len;
> };
>
> static LIST_HEAD(papr_nd_regions);
> @@ -200,6 +223,79 @@ static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
> return drc_pmem_bind(p);
> }
>
> +/*
> + * Query the Dimm performance stats from PHYP and copy them (if returned) to
> + * provided struct papr_scm_perf_stats instance 'stats' that can hold atleast
> + * (num_stats + header) bytes.
> + * - If buff_stats == NULL the return value is the size in byes of the buffer
> + * needed to hold all supported performance-statistics.
> + * - If buff_stats != NULL and num_stats == 0 then we copy all known
> + * performance-statistics to 'buff_stat' and expect to be large enough to
> + * hold them.
> + * - if buff_stats != NULL and num_stats > 0 then copy the requested
> + * performance-statistics to buff_stats.
> + */
> +static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
> + struct papr_scm_perf_stats *buff_stats,
> + unsigned int num_stats)
> +{
> + unsigned long ret[PLPAR_HCALL_BUFSIZE];
> + size_t size;
> + s64 rc;
> +
> + /* Setup the out buffer */
> + if (buff_stats) {
> + memcpy(buff_stats->eye_catcher,
> + PAPR_SCM_PERF_STATS_EYECATCHER, 8);
> + buff_stats->stats_version =
> + cpu_to_be32(PAPR_SCM_PERF_STATS_VERSION);
> + buff_stats->num_statistics =
> + cpu_to_be32(num_stats);
> +
> + /*
> + * Calculate the buffer size based on num-stats provided
> + * or use the prefetched max buffer length
> + */
> + if (num_stats)
> + /* Calculate size from the num_stats */
> + size = sizeof(struct papr_scm_perf_stats) +
> + num_stats * sizeof(struct papr_scm_perf_stat);
> + else
> + size = p->stat_buffer_len;
> + } else {
> + /* In case of no out buffer ignore the size */
> + size = 0;
> + }
> +
> + /* Do the HCALL asking PHYP for info */
> + rc = plpar_hcall(H_SCM_PERFORMANCE_STATS, ret, p->drc_index,
> + buff_stats ? virt_to_phys(buff_stats) : 0,
> + size);
> +
> + /* Check if the error was due to an unknown stat-id */
> + if (rc == H_PARTIAL) {
> + dev_err(&p->pdev->dev,
> + "Unknown performance stats, Err:0x%016lX\n", ret[0]);
> + return -ENOENT;
> + } else if (rc != H_SUCCESS) {
> + dev_err(&p->pdev->dev,
> + "Failed to query performance stats, Err:%lld\n", rc);
> + return -EIO;
> +
> + } else if (!size) {
> + /* Handle case where stat buffer size was requested */
> + dev_dbg(&p->pdev->dev,
> + "Performance stats size %ld\n", ret[0]);
> + return ret[0];
> + }
> +
> + /* Successfully fetched the requested stats from phyp */
> + dev_dbg(&p->pdev->dev,
> + "Performance stats returned %d stats\n",
> + be32_to_cpu(buff_stats->num_statistics));
> + return 0;
> +}
> +
> /*
> * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
> * health information.
> @@ -637,6 +733,48 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
> return 0;
> }
>
> +static ssize_t perf_stats_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int index, rc;
> + struct seq_buf s;
> + struct papr_scm_perf_stat *stat;
> + struct papr_scm_perf_stats *stats;
> + struct nvdimm *dimm = to_nvdimm(dev);
> + struct papr_scm_priv *p = nvdimm_provider_data(dimm);
> +
> + if (!p->stat_buffer_len)
> + return -ENOENT;
> +
> + /* Allocate the buffer for phyp where stats are written */
> + stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
> + if (!stats)
> + return -ENOMEM;
> +
> + /* Ask phyp to return all dimm perf stats */
> + rc = drc_pmem_query_stats(p, stats, 0);
> + if (rc)
> + goto free_stats;
So we end up making a HCALL for each read of the sysfs file? You do
throttle that for PAPR_HEALTH hcall (flags sysfs file). Do we need to do
that here? If not should we make this CAP_SYS_ADMIN? You can possibly
add is_visible callback to papr group and then restrict this all to
CAP_SYS_ADMIN?
> + /*
> + * Go through the returned output buffer and print stats and
> + * values. Since stat_id is essentially a char string of
> + * 8 bytes, simply use the string format specifier to print it.
> + */
> + seq_buf_init(&s, buf, PAGE_SIZE);
> + for (index = 0, stat = stats->scm_statistic;
> + index < be32_to_cpu(stats->num_statistics);
> + ++index, ++stat) {
> + seq_buf_printf(&s, "%.8s = 0x%016llX\n",
> + stat->stat_id,
> + be64_to_cpu(stat->stat_val));
> + }
> +
> +free_stats:
> + kfree(stats);
> + return rc ? rc : seq_buf_used(&s);
> +}
> +DEVICE_ATTR_RO(perf_stats);
> +
> static ssize_t flags_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -682,6 +820,7 @@ DEVICE_ATTR_RO(flags);
> /* papr_scm specific dimm attributes */
> static struct attribute *papr_nd_attributes[] = {
> &dev_attr_flags.attr,
> + &dev_attr_perf_stats.attr,
> NULL,
> };
>
> @@ -702,6 +841,7 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
> struct nd_region_desc ndr_desc;
> unsigned long dimm_flags;
> int target_nid, online_nid;
> + ssize_t stat_size;
>
> p->bus_desc.ndctl = papr_scm_ndctl;
> p->bus_desc.module = THIS_MODULE;
> @@ -769,6 +909,16 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
> list_add_tail(&p->region_list, &papr_nd_regions);
> mutex_unlock(&papr_ndr_lock);
>
> + /* Try retriving the stat buffer and see if its supported */
> + stat_size = drc_pmem_query_stats(p, NULL, 0);
> + if (stat_size > 0) {
> + p->stat_buffer_len = stat_size;
> + dev_dbg(&p->pdev->dev, "Max perf-stat size %lu-bytes\n",
> + p->stat_buffer_len);
> + } else {
> + dev_info(&p->pdev->dev, "Dimm performance stats unavailable\n");
> + }
> +
> return 0;
>
> err: nvdimm_bus_unregister(p->bus);
> --
> 2.26.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
2020-07-31 6:41 ` [PATCH v4 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric Vaibhav Jain
@ 2020-07-31 7:14 ` Aneesh Kumar K.V
0 siblings, 0 replies; 6+ messages in thread
From: Aneesh Kumar K.V @ 2020-07-31 7:14 UTC (permalink / raw)
To: Vaibhav Jain, linuxppc-dev, linux-nvdimm
Cc: Santosh Sivaraj, Oliver O'Halloran, Vaibhav Jain,
Dan Williams, Ira Weiny
Vaibhav Jain <vaibhav@linux.ibm.com> writes:
> 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'
>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---
> Changelog:
>
> v4:
> * Moved a hunk from this patch to previous patch in the series.
> [ Aneesh ]
>
> v3:
> * Updated papr_pdsm_fuel_guage() to use the updated
> drc_pmem_query_stats() function.
>
> Resend:
> None
>
> v2:
> * Restructure code in papr_pdsm_fuel_gauge() to handle error case
> first [ Ira ]
> * Ignore the return value of papr_pdsm_fuel_gauge() in
> papr_psdm_health() [ Ira ]
> ---
> 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:
> --
> 2.26.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric
2020-07-31 6:41 [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric Vaibhav Jain
2020-07-31 6:41 ` [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP Vaibhav Jain
2020-07-31 6:41 ` [PATCH v4 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric Vaibhav Jain
@ 2020-08-02 13:35 ` Michael Ellerman
2 siblings, 0 replies; 6+ messages in thread
From: Michael Ellerman @ 2020-08-02 13:35 UTC (permalink / raw)
To: linuxppc-dev, Vaibhav Jain, linux-nvdimm; +Cc: Aneesh Kumar K . V
On Fri, 31 Jul 2020 12:11:51 +0530, Vaibhav Jain wrote:
> Changes since v3[1]:
>
> * Fixed a rebase issue pointed out by Aneesh in first patch in the series.
>
> [1] https://lore.kernel.org/linux-nvdimm/20200730121303.134230-1-vaibhav@linux.ibm.com
Applied to powerpc/next.
[1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
https://git.kernel.org/powerpc/c/2d02bf835e5731de632c8a13567905fa7c0da01c
[2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
https://git.kernel.org/powerpc/c/af0870c4e75655b1931d0a5ffde2f448a2794362
cheers
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-08-02 14:16 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-07-31 6:41 [PATCH v4 0/2] powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric Vaibhav Jain
2020-07-31 6:41 ` [PATCH v4 1/2] powerpc/papr_scm: Fetch nvdimm performance stats from PHYP Vaibhav Jain
2020-07-31 7:12 ` Aneesh Kumar K.V
2020-07-31 6:41 ` [PATCH v4 2/2] powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric Vaibhav Jain
2020-07-31 7:14 ` Aneesh Kumar K.V
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