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2021-07-14powerpc/papr_scm: Make 'perf_stats' invisible if perf-stats unavailableVaibhav Jain1-3/+5
[ Upstream commit ed78f56e1271f108e8af61baeba383dcd77adbec ] 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. Even though 'perf_stats' attribute is available since v5.9, there are no known user-space tools/scripts that are dependent on presence of its sysfs file. Hence I dont expect any user-space breakage with this patch. Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP") Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210513092349.285021-1-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30docs: ABI: cleanup several ABI documentsMauro Carvalho Chehab1-8/+15
There are some ABI documents that, while they don't generate any warnings, they have issues when parsed by get_abi.pl script on its output result. Address them, in order to provide a clean output. Reviewed-by: Tom Rix <trix@redhat.com> # for fpga-manager Reviewed-By: Kajol Jain<kjain@linux.ibm.com> # for sysfs-bus-event_source-devices-hv_gpci and sysfs-bus-event_source-devices-hv_24x7 Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO Acked-by: Oded Gabbay <oded.gabbay@gmail.com> # for Habanalabs Acked-by: Vaibhav Jain <vaibhav@linux.ibm.com> # for sysfs-bus-papr-pmem Acked-by: Cezary Rojewski <cezary.rojewski@intel.com> # for catpt Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Ilya Dryomov <idryomov@gmail.com> # for rbd Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5bc78e5b68ed1e9e39135173857cb2e753be868f.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31powerpc/papr_scm: Fetch nvdimm performance stats from PHYPVaibhav Jain1-0/+27
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> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200731064153.182203-2-vaibhav@linux.ibm.com
2020-06-16powerpc/papr_scm: Fetch nvdimm health information from PHYPVaibhav Jain1-0/+27
Implement support for fetching nvdimm health information via H_SCM_HEALTH hcall as documented in Ref[1]. The hcall returns a pair of 64-bit bitmap, bitwise-and of which is then stored in 'struct papr_scm_priv' and subsequently partially exposed to user-space via newly introduced dimm specific attribute 'papr/flags'. Since the hcall is costly, the health information is cached and only re-queried, 60s after the previous successful hcall. The patch also adds a documentation text describing flags reported by the the new sysfs attribute 'papr/flags' is also introduced at Documentation/ABI/testing/sysfs-bus-papr-pmem. [1] commit 58b278f568f0 ("powerpc: Provide initial documentation for PAPR hcalls") Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20200615124407.32596-4-vaibhav@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>