From: Vaibhav Jain <vaibhav@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org
Cc: Santosh Sivaraj <santosh@fossix.org>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
Vaibhav Jain <vaibhav@linux.ibm.com>,
Dan Williams <dan.j.williams@intel.com>,
Ira Weiny <ira.weiny@intel.com>
Subject: [PATCH] powerpc/papr_scm: Make 'perf_stats' invisible if perf-stats unavailable
Date: Thu, 6 May 2021 00:47:08 +0530 [thread overview]
Message-ID: <20210505191708.51939-1-vaibhav@linux.ibm.com> (raw)
In case performance stats for an nvdimm are not available, reading the
'perf_stats' sysfs file returns an -ENOENT error. A better approach is
to make the 'perf_stats' file entirely invisible to indicate that
performance stats for an nvdimm are unavailable.
So this patch updates 'papr_nd_attribute_group' to add a 'is_visible'
callback implemented as newly introduced 'papr_nd_attribute_visible()'
that returns an appropriate mode in case performance stats aren't
supported in a given nvdimm.
Also the initialization of 'papr_scm_priv.stat_buffer_len' is moved
from papr_scm_nvdimm_init() to papr_scm_probe() so that it value is
available when 'papr_nd_attribute_visible()' is called during nvdimm
initialization.
Fixes: 2d02bf835e57('powerpc/papr_scm: Fetch nvdimm performance stats from PHYP')
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
arch/powerpc/platforms/pseries/papr_scm.c | 37 ++++++++++++++++-------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 12f1513f0fca..90f0af8fefe8 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -907,6 +907,20 @@ static ssize_t flags_show(struct device *dev,
}
DEVICE_ATTR_RO(flags);
+umode_t papr_nd_attribute_visible(struct kobject *kobj, struct attribute *attr,
+ int n)
+{
+ struct device *dev = container_of(kobj, typeof(*dev), kobj);
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+ struct papr_scm_priv *p = nvdimm_provider_data(nvdimm);
+
+ /* For if perf-stats not available remove perf_stats sysfs */
+ if (attr == &dev_attr_perf_stats.attr && p->stat_buffer_len == 0)
+ return 0;
+
+ return attr->mode;
+}
+
/* papr_scm specific dimm attributes */
static struct attribute *papr_nd_attributes[] = {
&dev_attr_flags.attr,
@@ -916,6 +930,7 @@ static struct attribute *papr_nd_attributes[] = {
static struct attribute_group papr_nd_attribute_group = {
.name = "papr",
+ .is_visible = papr_nd_attribute_visible,
.attrs = papr_nd_attributes,
};
@@ -931,7 +946,6 @@ 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;
@@ -1016,16 +1030,6 @@ 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);
@@ -1102,6 +1106,7 @@ static int papr_scm_probe(struct platform_device *pdev)
u64 blocks, block_size;
struct papr_scm_priv *p;
const char *uuid_str;
+ ssize_t stat_size;
u64 uuid[2];
int rc;
@@ -1179,6 +1184,16 @@ static int papr_scm_probe(struct platform_device *pdev)
p->res.name = pdev->name;
p->res.flags = IORESOURCE_MEM;
+ /* 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");
+ }
+
rc = papr_scm_nvdimm_init(p);
if (rc)
goto err2;
--
2.31.1
next reply other threads:[~2021-05-05 19:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 19:17 Vaibhav Jain [this message]
2021-05-05 22:53 ` [PATCH] powerpc/papr_scm: Make 'perf_stats' invisible if perf-stats unavailable kernel test robot
2021-05-06 5:02 ` Aneesh Kumar K.V
2021-05-07 11:40 ` Vaibhav Jain
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