powerpc/papr_scm: Move duplicate definitions to common header files

papr_scm and ndtest share common PDSM payload structs like
nd_papr_pdsm_health. Presently these structs are duplicated across
papr

powerpc/papr_scm: Move duplicate definitions to common header files

papr_scm and ndtest share common PDSM payload structs like
nd_papr_pdsm_health. Presently these structs are duplicated across
papr_pdsm.h and ndtest.h header files. Since 'ndtest' is essentially
arch independent and can run on platforms other than PPC64, a way
needs to be deviced to avoid redundancy and duplication of PDSM
structs in future.

So the patch proposes moving the PDSM header from arch/powerpc/include-
-/uapi/ to the generic include/uapi/linux directory. Also, there
are some #defines common between papr_scm and ndtest which are not
exported to the user space. So, move them to a header file which
can be shared across ndtest and papr_scm via newly introduced
include/linux/papr_scm.h.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/170638176942.112443.2937254675538057083.stgit@ltcd48-lp2.aus.stglab.ibm.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

show more ...

powerpc: papr_scm: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do e

powerpc: papr_scm: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/34847d756453af2e85e5944a8cc2e2c21aacc905.1708529736.git.u.kleine-koenig@pengutronix.de

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powerpc/papr_scm: Update the NUMA distance table for the target node

Platform device helper routines won't update the NUMA distance table
while creating a platform device, even if the device is pres

powerpc/papr_scm: Update the NUMA distance table for the target node

Platform device helper routines won't update the NUMA distance table
while creating a platform device, even if the device is present on a
NUMA node that doesn't have memory or CPU. This is especially true for
pmem devices. If the target node of the pmem device is not online, we
find the nearest online node to the device and associate the pmem device
with that online node. To find the nearest online node, we should have
the numa distance table updated correctly. Update the distance
information during the device probe.

For a papr scm device on NUMA node 3 distance_lookup_table value for
distance_ref_points_depth = 2 before and after fix is below:

Before fix:
node 3 distance depth 0 - 0
node 3 distance depth 1 - 0
node 4 distance depth 0 - 4
node 4 distance depth 1 - 2
node 5 distance depth 0 - 5
node 5 distance depth 1 - 1

After fix
node 3 distance depth 0 - 3
node 3 distance depth 1 - 1
node 4 distance depth 0 - 4
node 4 distance depth 1 - 2
node 5 distance depth 0 - 5
node 5 distance depth 1 - 1

Without the fix, the nearest numa node to the pmem device (NUMA node 3)
will be picked as 4. After the fix, we get the correct numa node which
is 5.

Fixes: da1115fdbd6e ("powerpc/nvdimm: Pick nearby online node if the device node is not online")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230404041433.1781804-1-aneesh.kumar@linux.ibm.com

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powerpc/papr_scm: Ensure rc is always initialized in papr_scm_pmu_register()

Clang warns:

arch/powerpc/platforms/pseries/papr_scm.c:492:6: warning: variable 'rc' is used uninitialized whenever 'i

powerpc/papr_scm: Ensure rc is always initialized in papr_scm_pmu_register()

Clang warns:

arch/powerpc/platforms/pseries/papr_scm.c:492:6: warning: variable 'rc' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (!p->stat_buffer_len)
^~~~~~~~~~~~~~~~~~~
arch/powerpc/platforms/pseries/papr_scm.c:523:64: note: uninitialized use occurs here
dev_info(&p->pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
^~
include/linux/dev_printk.h:150:67: note: expanded from macro 'dev_info'
dev_printk_index_wrap(_dev_info, KERN_INFO, dev, dev_fmt(fmt), ##__VA_ARGS__)
^~~~~~~~~~~
include/linux/dev_printk.h:110:23: note: expanded from macro 'dev_printk_index_wrap'
_p_func(dev, fmt, ##__VA_ARGS__); \
^~~~~~~~~~~
arch/powerpc/platforms/pseries/papr_scm.c:492:2: note: remove the 'if' if its condition is always false
if (!p->stat_buffer_len)
^~~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/platforms/pseries/papr_scm.c:484:8: note: initialize the variable 'rc' to silence this warning
int rc, nodeid;
^
= 0
1 warning generated.

The call to papr_scm_pmu_check_events() was eliminated but a return code
was not added to the if statement. Add the same return code from
papr_scm_pmu_check_events() for this condition so there is no more
warning.

Fixes: 9b1ac04698a4 ("powerpc/papr_scm: Fix nvdimm event mappings")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1701
Link: https://lore.kernel.org/r/20220830151256.1473169-1-nathan@kernel.org

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powerpc/papr_scm: Fix nvdimm event mappings

Commit 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
added performance monitoring support for papr-scm nvdimm devices via
perf interface.

powerpc/papr_scm: Fix nvdimm event mappings

Commit 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
added performance monitoring support for papr-scm nvdimm devices via
perf interface. Commit also added an array in papr_scm_priv
structure called "nvdimm_events_map", which got filled based on the
result of H_SCM_PERFORMANCE_STATS hcall.

Currently there is an assumption that the order of events in the
stats buffer, returned by the hypervisor is same. And order also
happens to matches with the events specified in nvdimm driver code.
But this assumption is not documented in Power Architecture
Platform Requirements (PAPR) document. Although the order
of events happens to be same on current generation od system, but
it might not be true in future generation systems. Fix the issue, by
adding a static mapping for nvdimm events to corresponding stat-id,
and removing the dynamic map from papr_scm_priv structure. Also
remove the function papr_scm_pmu_check_events from papr_scm.c file,
as we no longer need to copy stat-ids dynamically.

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220804074852.55157-1-kjain@linux.ibm.com

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powerpc: Fix all occurences of duplicate words

Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"")
fixed "the the", there's now a steady stream of patches fixing other
duplicate w

powerpc: Fix all occurences of duplicate words

Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"")
fixed "the the", there's now a steady stream of patches fixing other
duplicate words.

Just fix them all at once, to save the overhead of dealing with
individual patches for each case.

This leaves a few cases of "that that", which in some contexts is
correct.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718095158.326606-1-mpe@ellerman.id.au

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powerpc/papr_scm: use dev_get_drvdata

Eliminate direct accesses to the driver_data field.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link:

powerpc/papr_scm: use dev_get_drvdata

Eliminate direct accesses to the driver_data field.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1653988790-19999-1-git-send-email-baihaowen@meizu.com

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powerpc/papr_scm: don't requests stats with '0' sized stats buffer

Sachin reported [1] that on a POWER-10 lpar he is seeing a kernel panic being
reported with vPMEM when papr_scm probe is being call

powerpc/papr_scm: don't requests stats with '0' sized stats buffer

Sachin reported [1] that on a POWER-10 lpar he is seeing a kernel panic being
reported with vPMEM when papr_scm probe is being called. The panic is of the
form below and is observed only with following option disabled(profile) for the
said LPAR 'Enable Performance Information Collection' in the HMC:

Kernel attempted to write user page (1c) - exploit attempt? (uid: 0)
BUG: Kernel NULL pointer dereference on write at 0x0000001c
Faulting instruction address: 0xc008000001b90844
Oops: Kernel access of bad area, sig: 11 [#1]
<snip>
NIP [c008000001b90844] drc_pmem_query_stats+0x5c/0x270 [papr_scm]
LR [c008000001b92794] papr_scm_probe+0x2ac/0x6ec [papr_scm]
Call Trace:
0xc00000000941bca0 (unreliable)
papr_scm_probe+0x2ac/0x6ec [papr_scm]
platform_probe+0x98/0x150
really_probe+0xfc/0x510
__driver_probe_device+0x17c/0x230
<snip>
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception

On investigation looks like this panic was caused due to a 'stat_buffer' of
size==0 being provided to drc_pmem_query_stats() to fetch all performance
stats-ids of an NVDIMM. However drc_pmem_query_stats() shouldn't have been called
since the vPMEM NVDIMM doesn't support and performance stat-id's. This was caused
due to missing check for 'p->stat_buffer_len' at the beginning of
papr_scm_pmu_check_events() which indicates that the NVDIMM doesn't support
performance-stats.

Fix this by introducing the check for 'p->stat_buffer_len' at the beginning of
papr_scm_pmu_check_events().

[1] https://lore.kernel.org/all/6B3A522A-6A5F-4CC9-B268-0C63AA6E07D3@linux.ibm.com

Fixes: 0e0946e22f3665d2732 ("powerpc/papr_scm: Fix leaking nvdimm_events_map elements")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220524112353.1718454-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: Fix leaking nvdimm_events_map elements

Right now 'char *' elements allocated for individual 'stat_id' in
'papr_scm_priv.nvdimm_events_map[]' during papr_scm_pmu_check_events(), get

powerpc/papr_scm: Fix leaking nvdimm_events_map elements

Right now 'char *' elements allocated for individual 'stat_id' in
'papr_scm_priv.nvdimm_events_map[]' during papr_scm_pmu_check_events(), get
leaked in papr_scm_remove() and papr_scm_pmu_register(),
papr_scm_pmu_check_events() error paths.

Also individual 'stat_id' arent NULL terminated 'char *' instead they are fixed
8-byte sized identifiers. However papr_scm_pmu_register() assumes it to be a
NULL terminated 'char *' and at other places it assumes it to be a
'papr_scm_perf_stat.stat_id' sized string which is 8-byes in size.

Fix this by allocating the memory for papr_scm_priv.nvdimm_events_map to also
include space for 'stat_id' entries. This is possible since number of available
events/stat_ids are known upfront. This saves some memory and one extra level of
indirection from 'nvdimm_events_map' to 'stat_id'. Also rest of the code
can continue to call 'kfree(papr_scm_priv.nvdimm_events_map)' without needing to
iterate over the array and free up individual elements.

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220511082637.646714-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE

With CONFIG_FORTIFY_SOURCE enabled, string functions will also perform
dynamic checks for string size which can panic the kerne

powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE

With CONFIG_FORTIFY_SOURCE enabled, string functions will also perform
dynamic checks for string size which can panic the kernel, like incase
of overflow detection.

In papr_scm, papr_scm_pmu_check_events function uses stat->stat_id with
string operations, to populate the nvdimm_events_map array. Since
stat_id variable is not NULL terminated, the kernel panics with
CONFIG_FORTIFY_SOURCE enabled at boot time.

Below are the logs of kernel panic:

detected buffer overflow in __fortify_strlen
------------[ cut here ]------------
kernel BUG at lib/string_helpers.c:980!
Oops: Exception in kernel mode, sig: 5 [#1]
NIP [c00000000077dad0] fortify_panic+0x28/0x38
LR [c00000000077dacc] fortify_panic+0x24/0x38
Call Trace:
[c0000022d77836e0] [c00000000077dacc] fortify_panic+0x24/0x38 (unreliable)
[c00800000deb2660] papr_scm_pmu_check_events.constprop.0+0x118/0x220 [papr_scm]
[c00800000deb2cb0] papr_scm_probe+0x288/0x62c [papr_scm]
[c0000000009b46a8] platform_probe+0x98/0x150

Fix this issue by using kmemdup_nul() to copy the content of
stat->stat_id directly to the nvdimm_events_map array.

mpe: stat->stat_id comes from the hypervisor, not userspace, so there is
no security exposure.

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220505153451.35503-1-kjain@linux.ibm.com

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powerpc/papr_scm: Fix build failure when

The following build failure occurs when CONFIG_PERF_EVENTS is not set
as generic pmu functions are not visible in that scenario.

arch/powerpc/platforms/pser

powerpc/papr_scm: Fix build failure when

The following build failure occurs when CONFIG_PERF_EVENTS is not set
as generic pmu functions are not visible in that scenario.

arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct perf_event’ has no member named ‘attr’
p->nvdimm_events_map[event->attr.config],
^~
In file included from ./include/linux/list.h:5,
from ./include/linux/kobject.h:19,
from ./include/linux/of.h:17,
from arch/powerpc/platforms/pseries/papr_scm.c:5:
arch/powerpc/platforms/pseries/papr_scm.c: In function ‘papr_scm_pmu_event_init’:
arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct perf_event’ has no member named ‘pmu’
struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
^~
./include/linux/container_of.h:18:26: note: in definition of macro ‘container_of’
void *__mptr = (void *)(ptr); \
^~~
arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of macro ‘to_nvdimm_pmu’
struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
^~~~~~~~~~~~~
In file included from ./include/linux/bits.h:22,
from ./include/linux/bitops.h:6,
from ./include/linux/of.h:15,
from arch/powerpc/platforms/pseries/papr_scm.c:5:

Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
and also add stub function for papr_scm_pmu_register to handle
the CONFIG_PERF_EVENTS=n case. Also move the position of macro
"to_nvdimm_pmu" inorder to merge it in CONFIG_PERF_EVENTS=y block.

based on libnvdimm-for-next tree)

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") (Commit id
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Link: https://lore.kernel.org/r/20220323164550.109768-2-kjain@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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powerpc/papr_scm: Add perf interface support

Performance monitoring support for papr-scm nvdimm devices
via perf interface is added which includes addition of pmu
functions like add/del/read/event_i

powerpc/papr_scm: Add perf interface support

Performance monitoring support for papr-scm nvdimm devices
via perf interface is added which includes addition of pmu
functions like add/del/read/event_init for nvdimm_pmu struture.

A new parameter 'priv' in added to the pdev_archdata structure to save
nvdimm_pmu device pointer, to handle the unregistering of pmu device.

papr_scm_pmu_register function populates the nvdimm_pmu structure
with name, capabilities, cpumask along with event handling
functions. Finally the populated nvdimm_pmu structure is passed to
register the pmu device. Event handling functions internally uses
hcall to get events and counter data.

Result in power9 machine with 2 nvdimm device:

Ex: List all event by perf list

command:# perf list nmem

nmem0/cache_rh_cnt/ [Kernel PMU event]
nmem0/cache_wh_cnt/ [Kernel PMU event]
nmem0/cri_res_util/ [Kernel PMU event]
nmem0/ctl_res_cnt/ [Kernel PMU event]
nmem0/ctl_res_tm/ [Kernel PMU event]
nmem0/fast_w_cnt/ [Kernel PMU event]
nmem0/host_l_cnt/ [Kernel PMU event]
nmem0/host_l_dur/ [Kernel PMU event]
nmem0/host_s_cnt/ [Kernel PMU event]
nmem0/host_s_dur/ [Kernel PMU event]
nmem0/med_r_cnt/ [Kernel PMU event]
nmem0/med_r_dur/ [Kernel PMU event]
nmem0/med_w_cnt/ [Kernel PMU event]
nmem0/med_w_dur/ [Kernel PMU event]
nmem0/mem_life/ [Kernel PMU event]
nmem0/poweron_secs/ [Kernel PMU event]
...
nmem1/mem_life/ [Kernel PMU event]
nmem1/poweron_secs/ [Kernel PMU event]

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[Add numa_map_to_online_node function call to get online node id]
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@in.ibm.com>
Link: https://lore.kernel.org/r/20220225143024.47947-4-kjain@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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powerpc: declare unmodified attribute_group usages const

Inspired by (bd75b4ef4977: Constify static attribute_group structs),
accepted by linux-next, reported:
https://patchwork.ozlabs.org/project/l

powerpc: declare unmodified attribute_group usages const

Inspired by (bd75b4ef4977: Constify static attribute_group structs),
accepted by linux-next, reported:
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220210202805.7750-4-rikard.falkeborn@gmail.com/

Nearly all singletons of type struct attribute_group are never modified,
and so are candidates for being const. Declare them as const.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220307231414.86560-1-rmclure@linux.ibm.com

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powerpc/papr_scm: Implement initial support for injecting smart errors

Presently PAPR doesn't support injecting smart errors on an
NVDIMM. This makes testing the NVDIMM health reporting functionalit

powerpc/papr_scm: Implement initial support for injecting smart errors

Presently PAPR doesn't support injecting smart errors on an
NVDIMM. This makes testing the NVDIMM health reporting functionality
difficult as simulating NVDIMM health related events need a hacked up
qemu version.

To solve this problem this patch proposes simulating certain set of
NVDIMM health related events in papr_scm. Specifically 'fatal' health
state and 'dirty' shutdown state. These error can be injected via the
user-space 'ndctl-inject-smart(1)' command. With the proposed patch and
corresponding ndctl patches following command flow is expected:

$ sudo ndctl list -DH -d nmem0
...
"health_state":"ok",
"shutdown_state":"clean",
...
# inject unsafe shutdown and fatal health error
$ sudo ndctl inject-smart nmem0 -Uf
...
"health_state":"fatal",
"shutdown_state":"dirty",
...
# uninject all errors
$ sudo ndctl inject-smart nmem0 -N
...
"health_state":"ok",
"shutdown_state":"clean",
...

The patch adds a new member 'health_bitmap_inject_mask' inside struct
papr_scm_priv which is then bitwise ANDed to the health bitmap fetched from the
hypervisor. The value for 'health_bitmap_inject_mask' is accessible from sysfs
at nmemX/papr/health_bitmap_inject.

A new PDSM named 'SMART_INJECT' is proposed that accepts newly
introduced 'struct nd_papr_pdsm_smart_inject' as payload thats
exchanged between libndctl and papr_scm to indicate the requested
smart-error states.

When the processing the PDSM 'SMART_INJECT', papr_pdsm_smart_inject()
constructs a pair or 'inject_mask' and 'clear_mask' bitmaps from the payload
and bit-blt it to the 'health_bitmap_inject_mask'. This ensures the after being
fetched from the hypervisor, the health_bitmap reflects requested smart-error
states.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220124202204.1488346-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: trivial: fix typo in a comment

There is a spelling mistake "byes" -> "bytes" in a comment of
function drc_pmem_query_stats(). Fix that typo.

Signed-off-by: Kajol Jain <kjain@linux

powerpc/papr_scm: trivial: fix typo in a comment

There is a spelling mistake "byes" -> "bytes" in a comment of
function drc_pmem_query_stats(). Fix that typo.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210418074003.6651-1-kjain@linux.ibm.com

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powerpc/papr_scm: Add support for reporting dirty-shutdown-count

Persistent memory devices like NVDIMMs can loose cached writes in case
something prevents flush on power-fail. Such situations are te

powerpc/papr_scm: Add support for reporting dirty-shutdown-count

Persistent memory devices like NVDIMMs can loose cached writes in case
something prevents flush on power-fail. Such situations are termed as
dirty shutdown and are exposed to applications as
last-shutdown-state (LSS) flag and a dirty-shutdown-counter(DSC) as
described at [1]. The latter being useful in conditions where multiple
applications want to detect a dirty shutdown event without racing with
one another.

PAPR-NVDIMMs have so far only exposed LSS style flags to indicate a
dirty-shutdown-state. This patch further adds support for DSC via the
"ibm,persistence-failed-count" device tree property of an NVDIMM. This
property is a monotonic increasing 64-bit counter thats an indication
of number of times an NVDIMM has encountered a dirty-shutdown event
causing persistence loss.

Since this value is not expected to change after system-boot hence
papr_scm reads & caches its value during NVDIMM probe and exposes it
as a PAPR sysfs attributed named 'dirty_shutdown' to match the name of
similarly named NFIT sysfs attribute. Also this value is available to
libnvdimm via PAPR_PDSM_HEALTH payload. 'struct nd_papr_pdsm_health'
has been extended to add a new member called 'dimm_dsc' presence of
which is indicated by the newly introduced PDSM_DIMM_DSC_VALID flag.

References:
[1] https://pmem.io/documents/Dirty_Shutdown_Handling-V1.0.pdf

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210624080621.252038-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: Make 'perf_stats' invisible if perf-stats unavailable

In case performance stats for an nvdimm are not available, reading the
'perf_stats' sysfs file returns an -ENOENT error. A bet

powerpc/papr_scm: Make 'perf_stats' invisible if perf-stats unavailable

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

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powerpc/papr_scm: Properly handle UUID types and API

Parse to and export from UUID own type, before dereferencing.
This also fixes wrong comment (Little Endian UUID is something else)
and should eli

powerpc/papr_scm: Properly handle UUID types and API

Parse to and export from UUID own type, before dereferencing.
This also fixes wrong comment (Little Endian UUID is something else)
and should eliminate the direct strict types assignments.

Fixes: 43001c52b603 ("powerpc/papr_scm: Use ibm,unit-guid as the iset cookie")
Fixes: 259a948c4ba1 ("powerpc/pseries/scm: Use a specific endian format for storing uuid from the device tree")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210616134303.58185-1-andriy.shevchenko@linux.intel.com

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powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible

Currently drc_pmem_qeury_stats() generates a dev_err in case
"Enable Performance Information Collection" feature is disabled from

powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible

Currently drc_pmem_qeury_stats() generates a dev_err in case
"Enable Performance Information Collection" feature is disabled from
HMC or performance stats are not available for an nvdimm. The error is
of the form below:

papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Failed to query
performance stats, Err:-10

This error message confuses users as it implies a possible problem
with the nvdimm even though its due to a disabled/unavailable
feature. We fix this by explicitly handling the H_AUTHORITY and
H_UNSUPPORTED errors from the H_SCM_PERFORMANCE_STATS hcall.

In case of H_AUTHORITY error an info message is logged instead of an
error, saying that "Permission denied while accessing performance
stats" and an EPERM error is returned back.

In case of H_UNSUPPORTED error we return a EOPNOTSUPP error back from
drc_pmem_query_stats() indicating that performance stats-query
operation is not supported on this nvdimm.

Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210508043642.114076-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe

In case an nvdimm is found to be unarmed during probe then set its
NDD_UNARMED flag before nvdimm_create(). This would enforce a
read-

powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe

In case an nvdimm is found to be unarmed during probe then set its
NDD_UNARMED flag before nvdimm_create(). This would enforce a
read-only access to the ndimm region. Presently even if an nvdimm is
unarmed its not marked as read-only on ppc64 guests.

The patch updates papr_scm_nvdimm_init() to force query of nvdimm
health via __drc_pmem_query_health() and if nvdimm is found to be
unarmed then set the nvdimm flag ND_UNARMED for nvdimm_create().

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210329113103.476760-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: Fix build error due to wrong printf specifier

When I changed the rc variable to be long rather than int64_t I
neglected to update the printk(), leading to a build break:

arch/po

powerpc/papr_scm: Fix build error due to wrong printf specifier

When I changed the rc variable to be long rather than int64_t I
neglected to update the printk(), leading to a build break:

arch/powerpc/platforms/pseries/papr_scm.c: In function 'papr_scm_pmem_flush':
arch/powerpc/platforms/pseries/papr_scm.c:144:26: warning: format
'%lld' expects argument of type 'long long int', but argument 3 has
type 'long int' [-Wformat=]

Fixes: 75b7c05ebf90 ("powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210416111209.765444-2-mpe@ellerman.id.au

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powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall

Add support for ND_REGION_ASYNC capability if the device tree
indicates 'ibm,hcall-flush-required' property in the NVDIMM node.
Flush is don

powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall

Add support for ND_REGION_ASYNC capability if the device tree
indicates 'ibm,hcall-flush-required' property in the NVDIMM node.
Flush is done by issuing H_SCM_FLUSH hcall to the hypervisor.

If the flush request failed, the hypervisor is expected to
to reflect the problem in the subsequent nvdimm H_SCM_HEALTH call.

This patch prevents mmap of namespaces with MAP_SYNC flag if the
nvdimm requires an explicit flush[1].

References:
[1] https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/ndctl.py.data/map_sync.c

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Use unsigned long / long instead of uint64_t/int64_t]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161703936121.36.7260632399582101498.stgit@e1fbed493c87

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powerpc/papr_scm: Add PAPR command family to pass-through command-set

Add NVDIMM_FAMILY_PAPR to the list of valid 'dimm_family_mask'
acceptable by papr_scm. This is needed as since commit
92fe2aa859

powerpc/papr_scm: Add PAPR command family to pass-through command-set

Add NVDIMM_FAMILY_PAPR to the list of valid 'dimm_family_mask'
acceptable by papr_scm. This is needed as since commit
92fe2aa859f5 ("libnvdimm: Validate command family indices") libnvdimm
performs a validation of 'nd_cmd_pkg.nd_family' received as part of
ND_CMD_CALL processing to ensure only known command families can use
the general ND_CMD_CALL pass-through functionality.

Without this change the ND_CMD_CALL pass-through targeting
NVDIMM_FAMILY_PAPR error out with -EINVAL.

Fixes: 92fe2aa859f5 ("libnvdimm: Validate command family indices")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200913211904.24472-1-vaibhav@linux.ibm.com

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powerpc/papr_scm: Fix warnings about undeclared variable

Build the kernel with 'make C=2':
arch/powerpc/platforms/pseries/papr_scm.c:825:1: warning: symbol
'dev_attr_perf_stats' was not declared. Sh

powerpc/papr_scm: Fix warnings about undeclared variable

Build the kernel with 'make C=2':
arch/powerpc/platforms/pseries/papr_scm.c:825:1: warning: symbol
'dev_attr_perf_stats' was not declared. Should it be static?

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918085951.44983-1-wangwensheng4@huawei.com

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powerpc/papr_scm: Fix warning triggered by perf_stats_show()

A warning is reported by the kernel in case perf_stats_show() returns
an error code. The warning is of the form below:

papr_scm ibm,per

powerpc/papr_scm: Fix warning triggered by perf_stats_show()

A warning is reported by the kernel in case perf_stats_show() returns
an error code. The warning is of the form below:

papr_scm ibm,persistent-memory:ibm,pmemory@44100001:
Failed to query performance stats, Err:-10
dev_attr_show: perf_stats_show+0x0/0x1c0 [papr_scm] returned bad count
fill_read_buffer: dev_attr_show+0x0/0xb0 returned bad count

On investigation it looks like that the compiler is silently
truncating the return value of drc_pmem_query_stats() from 'long' to
'int', since the variable used to store the return code 'rc' is an
'int'. This truncated value is then returned back as a 'ssize_t' back
from perf_stats_show() to 'dev_attr_show()' which thinks of it as a
large unsigned number and triggers this warning..

To fix this we update the type of variable 'rc' from 'int' to
'ssize_t' that prevents the compiler from truncating the return value
of drc_pmem_query_stats() and returning correct signed value back from
perf_stats_show().

Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200912081451.66225-1-vaibhav@linux.ibm.com

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