Commit 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
adds performance monitoring support for papr-scm nvdimm devices via
perf interface. It also adds one array in papr_scm_priv
structure called "nvdimm_events_map", to dynamically save the stat_id
for events specified in nvdimm driver code "nd_perf.c".
Right now the mapping is done based on the result of
H_SCM_PERFORMANCE_STATS hcall, when all the stats are
requested. Currently there is an assumption, that a
certain stat will always be found at a specific offset
in the stat buffer. The assumption may not be true or
documented as part of PAPR documentation. Fixing it,
by adding a static mapping for nvdimm events to
corresponding stat-id, and removing the map from
papr_scm_priv structure.
Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
Reported-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
Signed-off-by: Kajol Jain <kj...@linux.ibm.com>
---
arch/powerpc/platforms/pseries/papr_scm.c | 59 ++++++++++-------------
1 file changed, 25 insertions(+), 34 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
b/arch/powerpc/platforms/pseries/papr_scm.c
index 181b855b3050..5434c654a797 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -124,9 +124,6 @@ struct papr_scm_priv {
/* The bits which needs to be overridden */
u64 health_bitmap_inject_mask;
-
- /* array to have event_code and stat_id mappings */
- u8 *nvdimm_events_map;
};
static int papr_scm_pmem_flush(struct nd_region *nd_region,
@@ -350,6 +347,26 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv
*p,
#ifdef CONFIG_PERF_EVENTS
#define to_nvdimm_pmu(_pmu) container_of(_pmu, struct nvdimm_pmu, pmu)
+static const char * const nvdimm_events_map[] = {
+ "N/A",
+ "CtlResCt",
+ "CtlResTm",
+ "PonSecs ",
+ "MemLife ",
+ "CritRscU",
+ "HostLCnt",
+ "HostSCnt",
+ "HostSDur",
+ "HostLDur",
+ "MedRCnt ",
+ "MedWCnt ",
+ "MedRDur ",
+ "MedWDur ",
+ "CchRHCnt",
+ "CchWHCnt",
+ "FastWCnt",
+};
+
static int papr_scm_pmu_get_value(struct perf_event *event, struct device
*dev, u64 *count)
{
struct papr_scm_perf_stat *stat;
@@ -361,7 +378,7 @@ static int papr_scm_pmu_get_value(struct perf_event *event,
struct device *dev,
size = sizeof(struct papr_scm_perf_stats) +
sizeof(struct papr_scm_perf_stat);
- if (!p || !p->nvdimm_events_map)
+ if (!p)
return -EINVAL;
stats = kzalloc(size, GFP_KERNEL);
@@ -370,7 +387,7 @@ static int papr_scm_pmu_get_value(struct perf_event *event,
struct device *dev,
stat = &stats->scm_statistic[0];
memcpy(&stat->stat_id,
- &p->nvdimm_events_map[event->attr.config *
sizeof(stat->stat_id)],
+ nvdimm_events_map[event->attr.config],
sizeof(stat->stat_id));
stat->stat_val = 0;
@@ -460,10 +477,9 @@ static void papr_scm_pmu_del(struct perf_event *event, int
flags)
static int papr_scm_pmu_check_events(struct papr_scm_priv *p, struct
nvdimm_pmu *nd_pmu)
{
- struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
u32 available_events;
- int index, rc = 0;
+ int rc = 0;
available_events = (p->stat_buffer_len - sizeof(struct
papr_scm_perf_stats))
/ sizeof(struct papr_scm_perf_stat);
@@ -473,34 +489,12 @@ static int papr_scm_pmu_check_events(struct papr_scm_priv
*p, struct nvdimm_pmu
/* Allocate the buffer for phyp where stats are written */
stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
if (!stats) {
- rc = -ENOMEM;
- return rc;
+ return -ENOMEM;
}
/* Called to get list of events supported */
rc = drc_pmem_query_stats(p, stats, 0);
- if (rc)
- goto out;
- /*
- * Allocate memory and populate nvdimm_event_map.
- * Allocate an extra element for NULL entry
- */
- p->nvdimm_events_map = kcalloc(available_events + 1,
- sizeof(stat->stat_id),
- GFP_KERNEL);
- if (!p->nvdimm_events_map) {
- rc = -ENOMEM;
- goto out;
- }
-
- /* Copy all stat_ids to event map */
- for (index = 0, stat = stats->scm_statistic;
- index < available_events; index++, ++stat) {
- memcpy(&p->nvdimm_events_map[index * sizeof(stat->stat_id)],
- &stat->stat_id, sizeof(stat->stat_id));
- }
-out:
kfree(stats);
return rc;
}
@@ -536,7 +530,7 @@ static void papr_scm_pmu_register(struct papr_scm_priv *p)
rc = register_nvdimm_pmu(nd_pmu, p->pdev);
if (rc)
- goto pmu_register_err;
+ goto pmu_check_events_err;
/*
* Set archdata.priv value to nvdimm_pmu structure, to handle the
@@ -545,8 +539,6 @@ static void papr_scm_pmu_register(struct papr_scm_priv *p)
p->pdev->archdata.priv = nd_pmu;
return;
-pmu_register_err:
- kfree(p->nvdimm_events_map);
pmu_check_events_err:
kfree(nd_pmu);
pmu_err_print:
@@ -1557,7 +1549,6 @@ static int papr_scm_remove(struct platform_device *pdev)
unregister_nvdimm_pmu(pdev->archdata.priv);
pdev->archdata.priv = NULL;
- kfree(p->nvdimm_events_map);
kfree(p->bus_desc.provider_name);
kfree(p);
--
2.31.1
