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

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

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

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

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

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

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

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

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

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>

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>

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

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

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

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

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

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

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

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

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

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

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

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

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

powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute

The newly introduced 'perf_stats' attribute uses the default access
mode of 0444, allowing non-root users to access performance stats of
an nvdimm and potentially force the kernel into issuing a large number
of expensive hypercalls. Since the information exposed by this
attribute cannot be cached it is better to ward off access to this
attribute from users who don't need to access to these performance
statistics.

Hence update the access mode of 'perf_stats' attribute to be only
readable by root users.

Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
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/20200907110540.21349-1-vaibhav@linux.ibm.com

powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric

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>
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/20200731064153.182203-3-vaibhav@linux.ibm.com

powerpc/papr_scm: Fetch nvdimm performance stats from PHYP

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

powerpc/papr_scm: Make some symbols static

The sparse tool complains as follows:

arch/powerpc/platforms/pseries/papr_scm.c:97:1: warning:
symbol 'papr_nd_regions' was not declared. Should it be static?
arch/powerpc/platforms/pseries/papr_scm.c:98:1: warning:
symbol 'papr_ndr_lock' was not declared. Should it be static?

Those variables are not used outside of papr_scm.c, so this
commit marks them static.

Fixes: 85343a8da2d9 ("powerpc/papr/scm: Add bad memory ranges to nvdimm bad ranges")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725091949.75234-1-weiyongjun1@huawei.com

powerpc/papr/scm: Add bad memory ranges to nvdimm bad ranges

Subscribe to the MCE notification and add the physical address which
generated a memory error to nvdimm bad range.

Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709135142.721504-2-santosh@fossix.org

powerpc/pmem: Initialize pmem device on newer hardware

With kernel now supporting new pmem flush/sync instructions, we can now
enable the kernel to initialize the device. On P10 these devices would
appear with a new compatible string. For PAPR device we have

compatible "ibm,pmemory-v2"

and for OF pmem device we have

compatible "pmem-region-v2"

Signed-off-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/20200701072235.223558-8-aneesh.kumar@linux.ibm.com

powerpc/papr_scm: Implement support for PAPR_PDSM_HEALTH

This patch implements support for PDSM request 'PAPR_PDSM_HEALTH'
that returns a newly introduced 'struct nd_papr_pdsm_health' instance
containing dimm health information back to user space in response to
ND_CMD_CALL. This functionality is implemented in newly introduced
papr_pdsm_health() that queries the nvdimm health information and
then copies this information to the package payload whose layout is
defined by 'struct nd_papr_pdsm_health'.

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/20200615124407.32596-7-vaibhav@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods

Introduce support for PAPR NVDIMM Specific Methods (PDSM) in papr_scm
module and add the command family NVDIMM_FAMILY_PAPR to the white list
of NVDIMM command sets. Also advertise support for ND_CMD_CALL for the
nvdimm command mask and implement necessary scaffolding in the module
to handle ND_CMD_CALL ioctl and PDSM requests that we receive.

The layout of the PDSM request as we expect from libnvdimm/libndctl is
described in newly introduced uapi header 'papr_pdsm.h' which
defines a 'struct nd_pkg_pdsm' and a maximal union named
'nd_pdsm_payload'. These new structs together with 'struct nd_cmd_pkg'
for a pdsm envelop thats sent by libndctl to libnvdimm and serviced by
papr_scm in 'papr_scm_service_pdsm()'. The PDSM request is
communicated by member 'struct nd_cmd_pkg.nd_command' together with
other information on the pdsm payload (size-in, size-out).

The patch also introduces 'struct pdsm_cmd_desc' instances of which
are stored in an array __pdsm_cmd_descriptors[] indexed with PDSM cmd
and corresponding access function pdsm_cmd_desc() is
introduced. 'struct pdsm_cdm_desc' holds the service function for a
given PDSM and corresponding payload in/out sizes.

A new function papr_scm_service_pdsm() is introduced and is called from
papr_scm_ndctl() in case of a PDSM request is received via ND_CMD_CALL
command from libnvdimm. The function performs validation on the PDSM
payload based on info present in corresponding PDSM descriptor and if
valid calls the 'struct pdcm_cmd_desc.service' function to service the
PDSM.

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/20200615124407.32596-6-vaibhav@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

powerpc/papr_scm: Improve error logging and handling papr_scm_ndctl()

Since papr_scm_ndctl() can be called from outside papr_scm, its
exposed to the possibility of receiving NULL as value of 'cmd_rc'
argument. This patch updates papr_scm_ndctl() to protect against such
possibility by assigning it pointer to a local variable in case cmd_rc
== NULL.

Finally the patch also updates the 'default' add a debug log unknown
'cmd' values.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.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/20200615124407.32596-5-vaibhav@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

powerpc/papr_scm: Fetch nvdimm health information from PHYP

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>

libnvdimm: Update persistence domain value for of_pmem and papr_scm device

Currently, kernel shows the below values
"persistence_domain":"cpu_cache"
"persistence_domain":"memory_controller"
"persistence_domain":"unknown"

"cpu_cache" indicates no extra instructions is needed to ensure the persistence
of data in the pmem media on power failure.

"memory_controller" indicates cpu cache flush instructions are required to flush
the data. Platform provides mechanisms to automatically flush outstanding
write data from memory controler to pmem on system power loss.

Based on the above use memory_controller for non volatile regions on ppc64.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20200324034821.60869-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm/region: Introduce NDD_LABELING

The NDD_ALIASING flag is used to indicate where pmem capacity might
alias with blk capacity and require labeling. It is also used to
indicate whether the DIMM supports labeling. Separate this latter
capability into its own flag so that the NDD_ALIASING flag is scoped to
true aliased configurations.

To my knowledge aliased configurations only exist in the ACPI spec,
there are no known platforms that ship this support in production.

This clarity allows namespace-capacity alignment constraints around
interleave-ways to be relaxed.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/158041477856.3889308.4212605617834097674.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

powerpc/papr_scm: Mark papr_scm_ndctl() as static

Function papr_scm_ndctl() is neither exported from the module nor
called directly from outside 'papr.c' hence should be marked 'static'.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200130040206.79998-1-vaibhav@linux.ibm.com

powerpc/papr_scm: Switch to numa_map_to_online_node()

Now that the core exports numa_map_to_online_node() switch to that
instead of the locally coded duplicate.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157401276263.43284.12616818803654229788.stgit@dwillia2-desk3.amr.corp.intel.com
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/158188325830.894464.9454884523846454529.stgit@dwillia2-desk3.amr.corp.intel.com

powerpc/papr_scm: Fix leaking 'bus_desc.provider_name' in some paths

String 'bus_desc.provider_name' allocated inside
papr_scm_nvdimm_init() will leaks in case call to
nvdimm_bus_register() fails or when papr_scm_remove() is called.

This minor patch ensures that 'bus_desc.provider_name' is freed in
error path for nvdimm_bus_register() as well as in papr_scm_remove().

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200122155140.120429-1-vaibhav@linux.ibm.com

powerpc/papr_scm: Don't enable direct map for a region by default

Setting ND_REGION_PAGEMAP flag implies namespace mode defaults to fsdax mode.
This also means kernel ends up creating struct page backing for these namspace
ranges. With large namespaces that is not the right thing to do. We
should let the user select the mode he/she wants the namespace to be created
with.

Hence disable ND_REGION_PAGEMAP for papr_scm regions. We still keep the flag for
of_pmem because it supports only small persistent memory regions.

This is similar to what is done for x86 with commit
commit: 004f1afbe199 ("libnvdimm, pmem: direct map legacy pmem by default")

Signed-off-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/20200108064647.169637-1-aneesh.kumar@linux.ibm.com

powerpc/papr_scm: Update debug message

Resource struct p->res is assigned later. Avoid using %pR before the resource
struct is assigned.

Signed-off-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/20191202063855.154321-1-aneesh.kumar@linux.ibm.com

libnvdimm: Move nvdimm_bus_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nvdimm_bus_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309903815.1582359.6418211876315050283.stgit@dwillia2-desk3.amr.corp.intel.com

libnvdimm: Move nvdimm_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nvdimm_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309903201.1582359.10966209746585062329.stgit@dwillia2-desk3.amr.corp.intel.com

libnvdimm: Move nd_mapping_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nd_mapping_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309902686.1582359.6749533709859492704.stgit@dwillia2-desk3.amr.corp.intel.com

libnvdimm: Move nd_region_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nd_region_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309902169.1582359.16828508538444551337.stgit@dwillia2-desk3.amr.corp.intel.com

libnvdimm: Move nd_numa_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nd_numa_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157401269537.43284.14411189404186877352.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm: Move nd_device_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nd_device_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

For regions this creates a new nd_region_attribute_groups[] added to the
per-region device-type instances.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309901138.1582359.12909354140826530394.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

powerpc/pseries: Fix platform_no_drv_owner.cocci warnings

Remove .owner field if calls are used which set it automatically
Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190218133950.95225-1-yuehaibing@huawei.com

powerpc/papr_scm: Fix an off-by-one check in papr_scm_meta_{get, set}

A validation check to prevent out of bounds read/write inside
functions papr_scm_meta_{get,set}() is off-by-one that prevent reads
and writes to the last byte of the label area.

This bug manifests as a failure to probe a dimm when libnvdimm is
unable to read the entire config-area as advertised by
ND_CMD_GET_CONFIG_SIZE. This usually happens when there are large
number of namespaces created in the region backed by the dimm and the
label-index spans max possible config-area. An error of the form below
usually reported in the kernel logs:

[ 255.293912] nvdimm: probe of nmem0 failed with error -22

The patch fixes these validation checks there by letting libnvdimm
access the entire config-area.

Fixes: 53e80bd042773('powerpc/nvdimm: Add support for multibyte read/write for metadata')
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/20190927062002.3169-1-vaibhav@linux.ibm.com

powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error

Right now we force an unbind of SCM memory at drcindex on H_OVERLAP error.
This really slows down operations like kexec where we get the H_OVERLAP
error because we don't go through a full hypervisor re init.

H_OVERLAP error for a H_SCM_BIND_MEM hcall indicates that SCM memory at
drc index is already bound. Since we don't specify a logical memory
address for bind hcall, we can use the H_SCM_QUERY hcall to query
the already bound logical address.

Boot time difference with and without patch is:

[ 5.583617] IOMMU table initialized, virtual merging enabled
[ 5.603041] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Retrying bind after unbinding
[ 301.514221] papr_scm ibm,persistent-memory:ibm,pmemory@44108001: Retrying bind after unbinding
[ 340.057238] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs

after fix

[ 5.101572] IOMMU table initialized, virtual merging enabled
[ 5.116984] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Querying SCM details
[ 5.117223] papr_scm ibm,persistent-memory:ibm,pmemory@44108001: Querying SCM details
[ 5.120530] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs

Signed-off-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/20190903123452.28620-2-aneesh.kumar@linux.ibm.com

powerpc/nvdimm: Use HCALL error as the return value

This simplifies the error handling and also enable us to switch to
H_SCM_QUERY hcall in a later patch on H_OVERLAP error.

We also do some kernel print formatting fixup in this patch.

Signed-off-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/20190903123452.28620-1-aneesh.kumar@linux.ibm.com

powerpc/nvdimm: Pick nearby online node if the device node is not online

Currently, nvdimm subsystem expects the device numa node for SCM device to be
an online node. It also doesn't try to bring the device numa node online. Hence
if we use a non-online numa node as device node we hit crashes like below. This
is because we try to access uninitialized NODE_DATA in different code paths.

cpu 0x0: Vector: 300 (Data Access) at [c0000000fac53170]
pc: c0000000004bbc50: ___slab_alloc+0x120/0xca0
lr: c0000000004bc834: __slab_alloc+0x64/0xc0
sp: c0000000fac53400
msr: 8000000002009033
dar: 73e8
dsisr: 80000
current = 0xc0000000fabb6d80
paca = 0xc000000003870000 irqmask: 0x03 irq_happened: 0x01
pid = 7, comm = kworker/u16:0
Linux version 5.2.0-06234-g76bd729b2644 (kvaneesh@ltc-boston123) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #135 SMP Thu Jul 11 05:36:30 CDT 2019
enter ? for help
[link register ] c0000000004bc834 __slab_alloc+0x64/0xc0
[c0000000fac53400] c0000000fac53480 (unreliable)
[c0000000fac53500] c0000000004bc818 __slab_alloc+0x48/0xc0
[c0000000fac53560] c0000000004c30a0 __kmalloc_node_track_caller+0x3c0/0x6b0
[c0000000fac535d0] c000000000cfafe4 devm_kmalloc+0x74/0xc0
[c0000000fac53600] c000000000d69434 nd_region_activate+0x144/0x560
[c0000000fac536d0] c000000000d6b19c nd_region_probe+0x17c/0x370
[c0000000fac537b0] c000000000d6349c nvdimm_bus_probe+0x10c/0x230
[c0000000fac53840] c000000000cf3cc4 really_probe+0x254/0x4e0
[c0000000fac538d0] c000000000cf429c driver_probe_device+0x16c/0x1e0
[c0000000fac53950] c000000000cf0b44 bus_for_each_drv+0x94/0x130
[c0000000fac539b0] c000000000cf392c __device_attach+0xdc/0x200
[c0000000fac53a50] c000000000cf231c bus_probe_device+0x4c/0xf0
[c0000000fac53a90] c000000000ced268 device_add+0x528/0x810
[c0000000fac53b60] c000000000d62a58 nd_async_device_register+0x28/0xa0
[c0000000fac53bd0] c0000000001ccb8c async_run_entry_fn+0xcc/0x1f0
[c0000000fac53c50] c0000000001bcd9c process_one_work+0x46c/0x860
[c0000000fac53d20] c0000000001bd4f4 worker_thread+0x364/0x5f0
[c0000000fac53db0] c0000000001c7260 kthread+0x1b0/0x1c0
[c0000000fac53e20] c00000000000b954 ret_from_kernel_thread+0x5c/0x68

The patch tries to fix this by picking the nearest online node as the SCM node.
This does have a problem of us losing the information that SCM node is
equidistant from two other online nodes. If applications need to understand these
fine-grained details we should express then like x86 does via
/sys/devices/system/node/nodeX/accessY/initiators/

With the patch we get

# numactl -H
available: 2 nodes (0-1)
node 0 cpus:
node 0 size: 0 MB
node 0 free: 0 MB
node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
node 1 size: 130865 MB
node 1 free: 129130 MB
node distances:
node 0 1
0: 10 20
1: 20 10
# cat /sys/bus/nd/devices/region0/numa_node
0
# dmesg | grep papr_scm
[ 91.332305] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Region registered with target node 2 and online node 0

Signed-off-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/20190729095128.23707-1-aneesh.kumar@linux.ibm.com

powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails

In some cases initial bind of scm memory for an lpar can fail if
previously it wasn't released using a scm-unbind hcall. This situation
can arise due to panic of the previous kernel or forced lpar
fadump. In such cases the H_SCM_BIND_MEM return a H_OVERLAP error.

To mitigate such cases the patch updates papr_scm_probe() to force a
call to drc_pmem_unbind() in case the initial bind of scm memory fails
with EBUSY error. In case scm-bind operation again fails after the
forced scm-unbind then we follow the existing error path. We also
update drc_pmem_bind() to handle the H_OVERLAP error returned by phyp
and indicate it as a EBUSY error back to the caller.

Suggested-by: "Oliver O'Halloran" <oohall@gmail.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190629160610.23402-4-vaibhav@linux.ibm.com

powerpc/papr_scm: Update drc_pmem_unbind() to use H_SCM_UNBIND_ALL

The new hcall named H_SCM_UNBIND_ALL has been introduce that can
unbind all or specific scm memory assigned to an lpar. This is
more efficient than using H_SCM_UNBIND_MEM as currently we don't
support partial unbind of scm memory.

Hence this patch proposes following changes to drc_pmem_unbind():

* Update drc_pmem_unbind() to replace hcall H_SCM_UNBIND_MEM to
H_SCM_UNBIND_ALL.

* Update drc_pmem_unbind() to handles cases when PHYP asks the guest
kernel to wait for specific amount of time before retrying the
hcall via the 'LONG_BUSY' return value.

* Ensure appropriate error code is returned back from the function
in case of an error.

Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190629160610.23402-3-vaibhav@linux.ibm.com

powerpc/pseries/scm: Use a specific endian format for storing uuid from the device tree

We used uuid_parse to convert uuid string from device tree to two u64
components. We want to make sure we look at the uuid read from device
tree in an endian-neutral fashion. For now, I am picking little-endian
to be format so that we don't end up doing an additional conversion.

The reason to store in a specific endian format is to enable reading
the namespace created with a little-endian kernel config on a
big-endian kernel. We do store the device tree uuid string as a 64-bit
little-endian cookie in the label area. When booting the kernel we
also compare this cookie against what is read from the device tree.
For this, to work we have to store and compare these values in a CPU
endian config independent fashion.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/nvdimm: Add support for multibyte read/write for metadata

SCM_READ/WRITE_MEATADATA hcall supports multibyte read/write. This patch
updates the metadata read/write to use 1, 2, 4 or 8 byte read/write as
mentioned in PAPR document.

READ/WRITE_METADATA hcall supports the 1, 2, 4, or 8 bytes read/write.
For other values hcall results H_P3.

Hypervisor stores the metadata contents in big-endian format and in-order
to enable read/write in different granularity, we need to switch the contents
to big-endian before calling HCALL.

Based on an patch from Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/pseries/scm: Mark the region volatile if cache flush not required

The device tree node is documented as below:

“ibm,cache-flush-required”:
property name indicates Cache Flush Required for this Persistent Memory Segment to persist memory
prop-encoded-array: None, this is a name only property.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/papr_scm: Use the correct bind address

When binding an SCM volume to a physical address the hypervisor has the
option to return early with a continue token with the expectation that
the guest will resume the bind operation until it completes. A quirk of
this interface is that the bind address will only be returned by the
first bind h-call and the subsequent calls will return
0xFFFF_FFFF_FFFF_FFFF for the bind address.

We currently do not save the address returned by the first h-call. As a
result we will use the junk address as the base of the bound region if
the hypervisor decides to split the bind across multiple h-calls. This
bug was found when testing with very large SCM volumes where the bind
process would take more time than they hypervisor's internal h-call time
limit would allow. This patch fixes the issue by saving the bind address
from the first call.

Cc: stable@vger.kernel.org
Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node

Persistent memory, as described by the ACPI NFIT (NVDIMM Firmware
Interface Table), is the first known instance of a memory range
described by a unique "target" proximity domain. Where "initiator" and
"target" proximity domains is an approach that the ACPI HMAT
(Heterogeneous Memory Attributes Table) uses to described the unique
performance properties of a memory range relative to a given initiator
(e.g. CPU or DMA device).

Currently the numa-node for a /dev/pmemX block-device or /dev/daxX.Y
char-device follows the traditional notion of 'numa-node' where the
attribute conveys the closest online numa-node. That numa-node attribute
is useful for cpu-binding and memory-binding processes *near* the
device. However, when the memory range backing a 'pmem', or 'dax' device
is onlined (memory hot-add) the memory-only-numa-node representing that
address needs to be differentiated from the set of online nodes. In
other words, the numa-node association of the device depends on whether
you can bind processes *near* the cpu-numa-node in the offline
device-case, or bind process *on* the memory-range directly after the
backing address range is onlined.

Allow for the case that platform firmware describes persistent memory
with a unique proximity domain, i.e. when it is distinct from the
proximity of DRAM and CPUs that are on the same socket. Plumb the Linux
numa-node translation of that proximity through the libnvdimm region
device to namespaces that are in device-dax mode. With this in place the
proposed kmem driver [1] can optionally discover a unique numa-node
number for the address range as it transitions the memory from an
offline state managed by a device-driver to an online memory range
managed by the core-mm.

[1]: https://lore.kernel.org/lkml/20181022201317.8558C1D8@viggo.jf.intel.com

Reported-by: Fan Du <fan.du@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

powerpc/papr_scm: Use ibm,unit-guid as the iset cookie

The interleave set cookie is used to determine if a label stored in the
metadata space should be applied to the current region. This is
important in the case of NVDIMMs since the firmware may change the
interleaving configuration of a DIMM which would invalidate the existing
labels. In our case the hypervisor hides those details from us so we
don't really care, but libnvdimm still requires the interleave set
cookie to be non-zero.

For our purposes we just need the set cookie to be unique and fixed for
a given PAPR SCM region and using the unit-guid (really a UUID) is fine
for this purpose.

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Use kernel types (u64)]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/papr_scm: Fix DIMM device registration race

When a new nvdimm device is registered with libnvdimm via
nvdimm_create() it is added as a device on the nvdimm bus. The probe
function for the DIMM driver is potentially quite slow so actually
registering and probing the device is done in an async domain rather
than immediately after device creation. This can result in a race where
the region device (created 2nd) is probed first and fails to activate at
boot.

To fix this we use the same approach as the ACPI/NFIT driver which is to
check that all the DIMM devices registered successfully. LibNVDIMM
provides the nvdimm_bus_count_dimms() function which synchronises with
the async domain and verifies that the dimm was successfully registered
with the bus.

If either of these does not occur then we bail.

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/papr_scm: Remove endian conversions

The return values of a h-call are returned in the CPU registers and
written to the provided buffer by the plpar_hcall() wrapper. As a result
the values written to memory are always in the native endian and should
not be byte swapped.

The inital implementation of the H-Call interface was done in qemu and
the returned values were byte swapped unnecessarily in both the
hypervisor and in the driver so this was only noticed when bringing up
the PowerVM implementation.

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/papr_scm: Update DT properties

The ibm,unit-sizes property was originally specified as an array of two
u32s corresponding to the memory block size, and the number of blocks
available in that region. A fairly last-minute change to the SCM DT
specification was splitting that into two seperate u64 properties:
ibm,block-sizes and ibm,number-of-blocks that convey the same
information. No firmware / hypervisor that emitted the ibm,unit-size
property ever appeared in the wild.

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Use kernel types (u32/u64)]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/papr_scm: Fix resource end address

Fix an off-by-one error in the memory resource range. This resource is
used to determine the address range of the memory to be hot-plugged as
ZONE_DEVICE memory. The current end address results in the kernel
attempting to map an additional memblock and the hypervisor may reject
the mapping resulting in the entire hot-plug failing.

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/pseries: Add driver for PAPR SCM regions

Adds a driver that implements support for enabling and accessing PAPR
SCM regions. Unfortunately due to how the PAPR interface works we can't
use the existing of_pmem driver (yet) because:

a) The guest is required to use the H_SCM_BIND_MEM h-call to add
add the SCM region to it's physical address space, and
b) There is currently no mechanism for relating a bare of_pmem region
to the backing DIMM (or not-a-DIMM for our case).

Both of these are easily handled by rolling the functionality into a
seperate driver so here we are...

Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>