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2023-10-11powerpc: Remove now superfluous sentinel element from ctl_table arraysJoel Granados1-1/+0
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel from powersave_nap_ctl_table and nmi_wd_lpm_factor_ctl_table. This removal is safe because register_sysctl implicitly uses ARRAY_SIZE() in addition to checking for the sentinel. Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-07-03powerpc: Include asm/nmi.c in mobility.c for ↵Douglas Anderson1-0/+1
watchdog_hardlockup_set_timeout_pct() The powerpc/platforms/pseries/mobility.c calls watchdog_hardlockup_set_timeout_pct(), which is declared in <asm/nmi.h>. We used to automatically get <asm/nmi.h> included, but that changed as of commit 7ca8fe94aa92 ("watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH"). Let's add the explicit include. Reported-by: Randy Dunlap <rdunlap@infradead.org> Closes: https://lore.kernel.org/r/af19b76d-aa4b-6c88-9cac-eae4b2072497@infradead.org Fixes: 7ca8fe94aa92 ("watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH") Signed-off-by: Douglas Anderson <dianders@chromium.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230629124500.1.I55e2f4e7903d686c4484cb23c033c6a9e1a9d4c4@changeid
2023-06-10watchdog/hardlockup: rename some "NMI watchdog" constants/functionDouglas Anderson1-2/+2
Do a search and replace of: - NMI_WATCHDOG_ENABLED => WATCHDOG_HARDLOCKUP_ENABLED - SOFT_WATCHDOG_ENABLED => WATCHDOG_SOFTOCKUP_ENABLED - watchdog_nmi_ => watchdog_hardlockup_ - nmi_watchdog_available => watchdog_hardlockup_available - nmi_watchdog_user_enabled => watchdog_hardlockup_user_enabled - soft_watchdog_user_enabled => watchdog_softlockup_user_enabled - NMI_WATCHDOG_DEFAULT => WATCHDOG_HARDLOCKUP_DEFAULT Then update a few comments near where names were changed. This is specifically to make it less confusing when we want to introduce the buddy hardlockup detector, which isn't using NMIs. As part of this, we sanitized a few names for consistency. [trix@redhat.com: make variables static] Link: https://lkml.kernel.org/r/20230525162822.1.I0fb41d138d158c9230573eaa37dc56afa2fb14ee@changeid Link: https://lkml.kernel.org/r/20230519101840.v5.12.I91f7277bab4bf8c0cb238732ed92e7ce7bbd71a6@changeid Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Tom Rix <trix@redhat.com> Reviewed-by: Tom Rix <trix@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-29Merge tag 'powerpc-6.4-1' of ↵Linus Torvalds1-9/+1
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Add support for building the kernel using PC-relative addressing on Power10. - Allow HV KVM guests on Power10 to use prefixed instructions. - Unify support for the P2020 CPU (85xx) into a single machine description. - Always build the 64-bit kernel with 128-bit long double. - Drop support for several obsolete 2000's era development boards as identified by Paul Gortmaker. - A series fixing VFIO on Power since some generic changes. - Various other small features and fixes. Thanks to Alexey Kardashevskiy, Andrew Donnellan, Benjamin Gray, Bo Liu, Christophe Leroy, Dan Carpenter, David Binderman, Ira Weiny, Joel Stanley, Kajol Jain, Kautuk Consul, Liang He, Luis Chamberlain, Masahiro Yamada, Michael Neuling, Nathan Chancellor, Nathan Lynch, Nicholas Miehlbradt, Nicholas Piggin, Nick Desaulniers, Nysal Jan K.A, Pali Rohár, Paul Gortmaker, Paul Mackerras, Petr Vaněk, Randy Dunlap, Rob Herring, Sachin Sant, Sean Christopherson, Segher Boessenkool, and Timothy Pearson. * tag 'powerpc-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (156 commits) powerpc/64s: Disable pcrel code model on Clang powerpc: Fix merge conflict between pcrel and copy_thread changes powerpc/configs/powernv: Add IGB=y powerpc/configs/64s: Drop JFS Filesystem powerpc/configs/64s: Use EXT4 to mount EXT2 filesystems powerpc/configs: Make pseries_defconfig an alias for ppc64le_guest powerpc/configs: Make pseries_le an alias for ppc64le_guest powerpc/configs: Incorporate generic kvm_guest.config into guest configs powerpc/configs: Add IBMVETH=y and IBMVNIC=y to guest configs powerpc/configs/64s: Enable Device Mapper options powerpc/configs/64s: Enable PSTORE powerpc/configs/64s: Enable VLAN support powerpc/configs/64s: Enable BLK_DEV_NVME powerpc/configs/64s: Drop REISERFS powerpc/configs/64s: Use SHA512 for module signatures powerpc/configs/64s: Enable IO_STRICT_DEVMEM powerpc/configs/64s: Enable SCHEDSTATS powerpc/configs/64s: Enable DEBUG_VM & other options powerpc/configs/64s: Enable EMULATED_STATS powerpc/configs/64s: Enable KUNIT and most tests ...
2023-03-29driver core: class: mark the struct class for sysfs callbacks as constantGreg Kroah-Hartman1-2/+2
struct class should never be modified in a sysfs callback as there is nothing in the structure to modify, and frankly, the structure is almost never used in a sysfs callback, so mark it as constant to allow struct class to be moved to read-only memory. While we are touching all class sysfs callbacks also mark the attribute as constant as it can not be modified. The bonding code still uses this structure so it can not be removed from the function callbacks. Cc: "David S. Miller" <davem@davemloft.net> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Russ Weight <russell.h.weight@intel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steve French <sfrench@samba.org> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: linux-cifs@vger.kernel.org Cc: linux-gpio@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-rdma@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: netdev@vger.kernel.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22powerpc: Simplify sysctl registration for nmi_wd_lpm_factor_ctl_tableLuis Chamberlain1-9/+1
There is no need to declare an extra tables to just create directory, this can be easily be done with a prefix path with register_sysctl(). Simplify this registration. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230310232850.3960676-3-mcgrof@kernel.org
2023-02-13powerpc/rtas: arch-wide function token lookup conversionsNathan Lynch1-2/+2
With the tokens for all implemented RTAS functions now available via rtas_function_token(), which is optimal and safe for arbitrary contexts, there is no need to use rtas_token() or cache its result. Most conversions are trivial, but a few are worth describing in more detail: * Error injection token comparisons for lockdown purposes are consolidated into a simple predicate: token_is_restricted_errinjct(). * A couple of special cases in block_rtas_call() do not use rtas_token() but perform string comparisons against names in the function table. These are converted to compare against token values instead, which is logically equivalent but less expensive. * The lookup for the ibm,os-term token can be deferred until needed, instead of caching it at boot to avoid device tree traversal during panic. * Since rtas_function_token() accesses a read-only data structure without taking any locks, xmon's lookup of set-indicator can be performed as needed instead of cached at startup. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-20-26929c8cce78@linux.ibm.com
2022-12-07powerpc/pseries: reset the RCU watchdogs after a LPMLaurent Dufour1-2/+5
The RCU watchdog timer should be reset when restarting the CPU after a Live Partition Mobility operation. Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Combine comments into a single comment block] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221125173204.15329-1-ldufour@linux.ibm.com
2022-09-28powerpc/pseries: Move vas_migration_handler early during migrationHaren Myneni1-3/+12
When the migration is initiated, the hypervisor changes VAS mappings as part of pre-migration event. Then the OS gets the migration event which closes all VAS windows before the migration starts. NX generates continuous faults until windows are closed and the user space can not differentiate these NX faults coming from the actual migration. So to reduce this time window, close VAS windows first in pseries_migrate_partition(). Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d8efade91dda831c9ed4abb226dab627da594c5f.camel@linux.ibm.com
2022-09-06powerpc/mobility: fix repeated words in commentsJilin Yuan1-1/+1
Delete the redundant word 'the'. Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220831005109.38314-1-yuanjilin@cdjrlc.com
2022-07-27powerpc/pseries/mobility: set NMI watchdog factor during an LPMLaurent Dufour1-0/+43
During an LPM, while the memory transfer is in progress on the arrival side, some latencies are generated when accessing not yet transferred pages on the arrival side. Thus, the NMI watchdog may be triggered too frequently, which increases the risk to hit an NMI interrupt in a bad place in the kernel, leading to a kernel panic. Disabling the Hard Lockup Watchdog until the memory transfer could be a too strong work around, some users would want this timeout to be eventually triggered if the system is hanging even during an LPM. Introduce a new sysctl variable nmi_watchdog_factor. It allows to apply a factor to the NMI watchdog timeout during an LPM. Just before the CPUs are stopped for the switchover sequence, the NMI watchdog timer is set to watchdog_thresh + factor% A value of 0 has no effect. The default value is 200, meaning that the NMI watchdog is set to 30s during LPM (based on a 10s watchdog_thresh value). Once the memory transfer is achieved, the factor is reset to 0. Setting this value to a high number is like disabling the NMI watchdog during an LPM. Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220713154729.80789-5-ldufour@linux.ibm.com
2022-07-25powerpc/mobility: wait for memory transfer to completeLaurent Dufour1-2/+46
In pseries_migration_partition(), loop until the memory transfer is complete. This way the calling drmgr process will not exit earlier, allowing callbacks to be run only once the migration is fully completed. If reading the VASI state is done after the hypervisor has completed the migration, the HCALL is returning H_PARAMETER. We can safely assume that the memory transfer is achieved if this happens. This will also allow to manage the NMI watchdog state in the next commits. Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220713154729.80789-2-ldufour@linux.ibm.com
2022-03-07powerpc/pseries/vas: Add VAS migration handlerHaren Myneni1-0/+5
Since the VAS windows belong to the VAS hardware resource, the hypervisor expects the partition to close them on source partition and reopen them after the partition migrated on the destination machine. This handler is called before pseries_suspend() to close these windows and again invoked after migration. All active windows for both default and QoS types will be closed and mark them inactive and reopened after migration with this handler. During the migration, the user space receives paste instruction failure if it issues copy/paste on these inactive windows. The current migration implementation does not freeze the user space and applications can continue to open VAS windows while migration is in progress. So when the migration_in_progress flag is set, VAS open window API returns -EBUSY. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/05e45ff4f8babd2490ccb7ae923884f4aa21a7e5.camel@linux.ibm.com
2022-02-12powerpc/pseries: make pseries_devicetree_update() staticNathan Lynch1-1/+1
pseries_devicetree_update() has only one call site, in the same file in which it is defined. Make it static. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220207221247.354454-1-nathanl@linux.ibm.com
2021-12-09powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMUNicholas Piggin1-0/+4
Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves 128kB kernel image size (90kB text) on powernv_defconfig minus KVM, 350kB on pseries_defconfig minus KVM, 40kB on a tiny config. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG. Fix radix_enabled() use in setup_initial_memory_limit(). Add some stubs to reduce number of ifdefs.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com
2021-10-22powerpc/pseries/mobility: ignore ibm, platform-facilities updatesNathan Lynch1-0/+34
On VMs with NX encryption, compression, and/or RNG offload, these capabilities are described by nodes in the ibm,platform-facilities device tree hierarchy: $ tree -d /sys/firmware/devicetree/base/ibm,platform-facilities/ /sys/firmware/devicetree/base/ibm,platform-facilities/ ├── ibm,compression-v1 ├── ibm,random-v1 └── ibm,sym-encryption-v1 3 directories The acceleration functions that these nodes describe are not disrupted by live migration, not even temporarily. But the post-migration ibm,update-nodes sequence firmware always sends "delete" messages for this hierarchy, followed by an "add" directive to reconstruct it via ibm,configure-connector (log with debugging statements enabled in mobility.c): mobility: removing node /ibm,platform-facilities/ibm,random-v1:4294967285 mobility: removing node /ibm,platform-facilities/ibm,compression-v1:4294967284 mobility: removing node /ibm,platform-facilities/ibm,sym-encryption-v1:4294967283 mobility: removing node /ibm,platform-facilities:4294967286 ... mobility: added node /ibm,platform-facilities:4294967286 Note we receive a single "add" message for the entire hierarchy, and what we receive from the ibm,configure-connector sequence is the top-level platform-facilities node along with its three children. The debug message simply reports the parent node and not the whole subtree. Also, significantly, the nodes added are almost completely equivalent to the ones removed; even phandles are unchanged. ibm,shared-interrupt-pool in the leaf nodes is the only property I've observed to differ, and Linux does not use that. So in practice, the sum of update messages Linux receives for this hierarchy is equivalent to minor property updates. We succeed in removing the original hierarchy from the device tree. But the vio bus code is ignorant of this, and does not unbind or relinquish its references. The leaf nodes, still reachable through sysfs, of course still refer to the now-freed ibm,platform-facilities parent node, which makes use-after-free possible: refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 1706 at lib/refcount.c:25 refcount_warn_saturate+0x164/0x1f0 refcount_warn_saturate+0x160/0x1f0 (unreliable) kobject_get+0xf0/0x100 of_node_get+0x30/0x50 of_get_parent+0x50/0xb0 of_fwnode_get_parent+0x54/0x90 fwnode_count_parents+0x50/0x150 fwnode_full_name_string+0x30/0x110 device_node_string+0x49c/0x790 vsnprintf+0x1c0/0x4c0 sprintf+0x44/0x60 devspec_show+0x34/0x50 dev_attr_show+0x40/0xa0 sysfs_kf_seq_show+0xbc/0x200 kernfs_seq_show+0x44/0x60 seq_read_iter+0x2a4/0x740 kernfs_fop_read_iter+0x254/0x2e0 new_sync_read+0x120/0x190 vfs_read+0x1d0/0x240 Moreover, the "new" replacement subtree is not correctly added to the device tree, resulting in ibm,platform-facilities parent node without the appropriate leaf nodes, and broken symlinks in the sysfs device hierarchy: $ tree -d /sys/firmware/devicetree/base/ibm,platform-facilities/ /sys/firmware/devicetree/base/ibm,platform-facilities/ 0 directories $ cd /sys/devices/vio ; find . -xtype l -exec file {} + ./ibm,sym-encryption-v1/of_node: broken symbolic link to ../../../firmware/devicetree/base/ibm,platform-facilities/ibm,sym-encryption-v1 ./ibm,random-v1/of_node: broken symbolic link to ../../../firmware/devicetree/base/ibm,platform-facilities/ibm,random-v1 ./ibm,compression-v1/of_node: broken symbolic link to ../../../firmware/devicetree/base/ibm,platform-facilities/ibm,compression-v1 This is because add_dt_node() -> dlpar_attach_node() attaches only the parent node returned from configure-connector, ignoring any children. This should be corrected for the general case, but fixing that won't help with the stale OF node references, which is the more urgent problem. One way to address that would be to make the drivers respond to node removal notifications, so that node references can be dropped appropriately. But this would likely force the drivers to disrupt active clients for no useful purpose: equivalent nodes are immediately re-added. And recall that the acceleration capabilities described by the nodes remain available throughout the whole process. The solution I believe to be robust for this situation is to convert remove+add of a node with an unchanged phandle to an update of the node's properties in the Linux device tree structure. That would involve changing and adding a fair amount of code, and may take several iterations to land. Until that can be realized we have a confirmed use-after-free and the possibility of memory corruption. So add a limited workaround that discriminates on the node type, ignoring adds and removes. This should be amenable to backporting in the meantime. Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Cc: stable@vger.kernel.org Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211020194703.2613093-1-nathanl@linux.ibm.com
2021-03-23powerpc/pseries/mobility: handle premature return from H_JOINNathan Lynch1-1/+25
The pseries join/suspend sequence in its current form was written with the assumption that it was the only user of H_PROD and that it needn't handle spurious successful returns from H_JOIN. That's wrong; powerpc's paravirt spinlock code uses H_PROD, and CPUs entering do_join() can be woken prematurely from H_JOIN with a status of H_SUCCESS as a result. This causes all CPUs to exit the sequence early, preventing suspend from occurring at all. Add a 'done' boolean flag to the pseries_suspend_info struct, and have the waking thread set it before waking the other threads. Threads which receive H_SUCCESS from H_JOIN retry if the 'done' flag is still unset. Fixes: 9327dc0aeef3 ("powerpc/pseries/mobility: use stop_machine for join/suspend") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210315080045.460331-3-nathanl@linux.ibm.com
2021-03-23powerpc/pseries/mobility: use struct for shared stateNathan Lynch1-3/+19
The atomic_t counter is the only shared state for the join/suspend sequence so far, but that will change. Contain it in a struct (pseries_suspend_info), and document its intended use. No functional change. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210315080045.460331-2-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: refactor node lookup during DT updateNathan Lynch1-32/+17
In pseries_devicetree_update(), with each call to ibm,update-nodes the partition firmware communicates the node to be deleted or updated by placing its phandle in the work buffer. Each of delete_dt_node(), update_dt_node(), and add_dt_node() have duplicate lookups using the phandle value and corresponding refcount management. Move the lookup and of_node_put() into pseries_devicetree_update(), and emit a warning on any failed lookups. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-29-nathanl@linux.ibm.com
2020-12-08powerpc/rtas: dispatch partition migration requests to pseriesNathan Lynch1-0/+5
sys_rtas() cannot call ibm,suspend-me directly in the same way it handles other inputs. Instead it must dispatch the request to code that can first perform the H_JOIN sequence before any call to ibm,suspend-me can succeed. Over time kernel/rtas.c has accreted a fair amount of platform-specific code to implement this. Since a different, more robust implementation of the suspend sequence is now in the pseries platform code, we want to dispatch the request there. Note that invoking ibm,suspend-me via the RTAS syscall is all but deprecated; this change preserves ABI compatibility for old programs while providing to them the benefit of the new partition suspend implementation. This is a behavior change in that the kernel performs the device tree update and firmware activation before returning, but experimentation indicates this is tolerated fine by legacy user space. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-16-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: retry partition suspend after errorNathan Lynch1-2/+57
This is a mitigation for the relatively rare occurrence where a virtual IOA can be in a transient state that prevents the suspend/migration from succeeding, resulting in an error from ibm,suspend-me. If the join/suspend sequence returns an error, it is acceptable to retry as long as the VASI suspend session state is still "Suspending" (i.e. the platform is still waiting for the OS to suspend). Retry a few times on suspend failure while this condition holds, progressively increasing the delay between attempts. We don't want to retry indefinitey because firmware emits an error log event on each unsuccessful attempt. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-15-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: signal suspend cancellation to platformNathan Lynch1-0/+31
If we're returning an error to user space, use H_VASI_SIGNAL to send a cancellation request to the platform. This isn't strictly required but it communicates that Linux will not attempt to complete the suspend, which allows the various entities involved to promptly end the operation in progress. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-14-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: use stop_machine for join/suspendNathan Lynch1-7/+125
The partition suspend sequence as specified in the platform architecture requires that all active processor threads call H_JOIN, which: - suspends the calling thread until it is the target of an H_PROD; or - immediately returns H_CONTINUE, if the calling thread is the last to call H_JOIN. This thread is expected to call ibm,suspend-me to completely suspend the partition. Upon returning from ibm,suspend-me the calling thread must wake all others using H_PROD. rtas_ibm_suspend_me_unsafe() uses on_each_cpu() to implement this protocol, but because of its synchronizing nature this is susceptible to deadlock versus users of stop_machine() or other callers of on_each_cpu(). Not only is stop_machine() intended for use cases like this, it handles error propagation and allows us to keep the data shared between CPUs minimal: a single atomic counter which ensures exactly one CPU will wake the others from their joined states. Switch the migration code to use stop_machine() and a less complex local implementation of the H_JOIN/ibm,suspend-me logic, which carries additional benefits: - more informative error reporting, appropriately ratelimited - resets the lockup detector / watchdog on resume to prevent lockup warnings when the OS has been suspended for a time exceeding the threshold. Fixes: 91dc182ca6e2 ("[PATCH] powerpc: special-case ibm,suspend-me RTAS call") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-13-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: extract VASI session polling logicNathan Lynch1-5/+64
The behavior of rtas_ibm_suspend_me_unsafe() is to return -EAGAIN to the caller until the specified VASI suspend session state makes the transition from H_VASI_ENABLED to H_VASI_SUSPENDING. In the interest of separating concerns to prepare for a new implementation of the join/suspend sequence, extract VASI session polling logic into a couple of local functions. Waiting for the session state to reach H_VASI_SUSPENDING before calling rtas_ibm_suspend_me_unsafe() ensures that we will never get an EAGAIN result necessitating a retry. No user-visible change in behavior is intended. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-12-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: use rtas_activate_firmware() on resumeNathan Lynch1-14/+1
It's incorrect to abort post-suspend processing if ibm,activate-firmware isn't available. Use rtas_activate_firmware(), which logs this condition appropriately and allows us to proceed. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-11-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: error message improvementsNathan Lynch1-4/+3
- Convert printk(KERN_ERR) to pr_err(). - Include errno in property update failure message. - Remove reference to "Post-mobility" from device tree update message: with pr_err() it will have a "mobility:" prefix. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-10-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: add missing break to default caseNathan Lynch1-0/+1
update_dt_node() has a switch statement where the default case lacks a break statement. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-9-nathanl@linux.ibm.com
2020-12-08powerpc/pseries/mobility: don't error on absence of ibm, update-nodesNathan Lynch1-1/+1
Treat the absence of the ibm,update-nodes function as benign instead of reporting an error. If the platform does not provide that facility, it's not a problem for Linux. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-8-nathanl@linux.ibm.com
2020-12-08powerpc/rtas: rtas_ibm_suspend_me -> rtas_ibm_suspend_me_unsafeNathan Lynch1-1/+1
The pseries partition suspend sequence requires that all active CPUs call H_JOIN, which suspends all but one of them with interrupts disabled. The "chosen" CPU is then to call ibm,suspend-me to complete the suspend. Upon returning from ibm,suspend-me, the chosen CPU is to use H_PROD to wake the joined CPUs. Using on_each_cpu() for this, as rtas_ibm_suspend_me() does to implement partition migration, is susceptible to deadlock with other users of on_each_cpu() and with users of stop_machine APIs. The callback passed to on_each_cpu() is not allowed to synchronize with other CPUs in the way it is used here. Complicating the fix is the fact that rtas_ibm_suspend_me() also occupies the function name that should be used to provide a more conventional wrapper for ibm,suspend-me. Rename rtas_ibm_suspend_me() to rtas_ibm_suspend_me_unsafe() to free up the name and indicate that it should not gain users. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-4-nathanl@linux.ibm.com
2020-11-19powerpc/64s: rename pnv|pseries_setup_rfi_flush to _setup_security_mitigationsDaniel Axtens1-2/+2
pseries|pnv_setup_rfi_flush already does the count cache flush setup, and we just added entry and uaccess flushes. So the name is not very accurate any more. In both platforms we then also immediately setup the STF flush. Rename them to _setup_security_mitigations and fold the STF flush in. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2020-07-30powerpc/pseries/mobility: Add pr_debug() for device tree changesNathan Lynch1-0/+5
When investigating issues with partition migration or resource reassignments it is helpful to have a log of which nodes and properties in the device tree have changed. Use pr_debug() so it's easy to enable these at runtime with the dynamic debug facility. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190627053044.9238-3-nathanl@linux.ibm.com
2020-07-30powerpc/pseries/mobility: Set pr_fmt()Nathan Lynch1-2/+5
The pr_err() callsites in mobility.c already manually include a "mobility:" prefix, let's make it official for the benefit of messages to be added later. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190627053044.9238-2-nathanl@linux.ibm.com
2020-07-16powerpc/pseries: remove prrn special case from DT update pathNathan Lynch1-27/+0
pseries_devicetree_update() is no longer called with PRRN_SCOPE. The purpose of prrn_update_node() was to remove and then add back a LMB whose NUMA assignment had changed. This has never been reliable, and this codepath has been default-disabled for several releases. Remove prrn_update_node(). Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-16-nathanl@linux.ibm.com
2020-07-16powerpc/numa: remove start/stop_topology_update()Nathan Lynch1-4/+0
These APIs have become no-ops, so remove them and all call sites. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-12-nathanl@linux.ibm.com
2020-05-28powerpc/pseries: Update hv-24x7 information after migrationKajol Jain1-0/+3
Function 'read_sys_info_pseries()' is added to get system parameter values like number of sockets and chips per socket. and it gets these details via rtas_call with token "PROCESSOR_MODULE_INFO". Incase lpar migrate from one system to another, system parameter details like chips per sockets or number of sockets might change. So, it needs to be re-initialized otherwise, these values corresponds to previous system values. This patch adds a call to 'read_sys_info_pseries()' from 'post-mobility_fixup()' to re-init the physsockets and physchips values Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525104308.9814-6-kjain@linux.ibm.com
2019-08-20powerpc/pseries/mobility: use cond_resched when updating device treeNathan Lynch1-0/+9
After a partition migration, pseries_devicetree_update() processes changes to the device tree communicated from the platform to Linux. This is a relatively heavyweight operation, with multiple device tree searches, memory allocations, and conversations with partition firmware. There's a few levels of nested loops which are bounded only by decisions made by the platform, outside of Linux's control, and indeed we have seen RCU stalls on large systems while executing this call graph. Use cond_resched() in these loops so that the cpu is yielded when needed. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802192926.19277-4-nathanl@linux.ibm.com
2019-07-14Merge tag 'powerpc-5.3-1' of ↵Linus Torvalds1-0/+19
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well as some other functions only used by drivers that haven't (yet?) made it upstream. - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e mem: ...) which could lead to register corruption and kernel crashes. - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc when using the Radix MMU. - A large but incremental rewrite of our exception handling code to use gas macros rather than multiple levels of nested CPP macros. And the usual small fixes, cleanups and improvements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung Bauermann, YueHaibing" * tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits) powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state. powerpc/eeh: Handle hugepages in ioremap space ocxl: Update for AFU descriptor template version 1.1 powerpc/boot: pass CONFIG options in a simpler and more robust way powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h powerpc/irq: Don't WARN continuously in arch_local_irq_restore() powerpc/module64: Use symbolic instructions names. powerpc/module32: Use symbolic instructions names. powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h powerpc/module64: Fix comment in R_PPC64_ENTRY handling powerpc/boot: Add lzo support for uImage powerpc/boot: Add lzma support for uImage powerpc/boot: don't force gzipped uImage powerpc/8xx: Add microcode patch to move SMC parameter RAM. powerpc/8xx: Use IO accessors in microcode programming. powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c powerpc/8xx: refactor programming of microcode CPM params. powerpc/8xx: refactor printing of microcode patch name. powerpc/8xx: Refactor microcode write powerpc/8xx: refactor writing of CPM microcode arrays ...
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-15powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migrationNathan Lynch1-0/+10
It's common for the platform to replace the cache device nodes after a migration. Since the cacheinfo code is never informed about this, it never drops its references to the source system's cache nodes, causing it to wind up in an inconsistent state resulting in warnings and oopses as soon as CPU online/offline occurs after the migration, e.g. cache for /cpus/l3-cache@3113(Unified) refers to cache for /cpus/l2-cache@200d(Unified) WARNING: CPU: 15 PID: 86 at arch/powerpc/kernel/cacheinfo.c:176 release_cache+0x1bc/0x1d0 [...] NIP release_cache+0x1bc/0x1d0 LR release_cache+0x1b8/0x1d0 Call Trace: release_cache+0x1b8/0x1d0 (unreliable) cacheinfo_cpu_offline+0x1c4/0x2c0 unregister_cpu_online+0x1b8/0x260 cpuhp_invoke_callback+0x114/0xf40 cpuhp_thread_fun+0x270/0x310 smpboot_thread_fn+0x2c8/0x390 kthread+0x1b8/0x1c0 ret_from_kernel_thread+0x5c/0x68 Using device tree notifiers won't work since we want to rebuild the hierarchy only after all the removals and additions have occurred and the device tree is in a consistent state. Call cacheinfo_teardown() before processing device tree updates, and rebuild the hierarchy afterward. Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-15powerpc/pseries/mobility: prevent cpu hotplug during DT updateNathan Lynch1-0/+9
CPU online/offline code paths are sensitive to parts of the device tree (various cpu node properties, cache nodes) that can be changed as a result of a migration. Prevent CPU hotplug while the device tree potentially is inconsistent. Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-13powerpc/pseries/mobility: Extend start/stop topology update scopeMichael Bringmann1-0/+5
The powerpc mobility code may receive RTAS requests to perform PRRN (Platform Resource Reassignment Notification) topology changes at any time, including during LPAR migration operations. In some configurations where the affinity of CPUs or memory is being changed on that platform, the PRRN requests may apply or refer to outdated information prior to the complete update of the device-tree. This patch changes the duration for which topology updates are suppressed during LPAR migrations from just the rtas_ibm_suspend_me() / 'ibm,suspend-me' call(s) to cover the entire migration_store() operation to allow all changes to the device-tree to be applied prior to accepting and applying any PRRN requests. For tracking purposes, pr_info notices are added to the functions start_topology_update() and stop_topology_update() of 'numa.c'. Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Remove unneeded uses of dlpar work queueNathan Fontenot1-12/+6
There are three instances in which dlpar hotplug events are invoked; handling a hotplug interrupt (in a kvm guest), handling a dlpar request through sysfs, and updating LMB affinity when handling a PRRN event. Only in the case of handling a hotplug interrupt do we have to put the work on a workqueue, the other cases can handle the dlpar request directly. This patch exports the handle_dlpar_errorlog() function so that dlpar hotplug events can be handled directly and updates the two instances mentioned above to use the direct invocation. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc: clean the inclusion of stringify.hChristophe Leroy1-0/+1
Only include linux/stringify.h is files using __stringify() Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/rfi-flush: Call setup_rfi_flush() after LPM migrationMichael Ellerman1-0/+3
We might have migrated to a machine that uses a different flush type, or doesn't need flushing at all. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-21powerpc: Use octal numbers for file permissionsRussell Currey1-1/+1
Symbolic macros are unintuitive and hard to read, whereas octal constants are much easier to interpret. Replace macros for the basic permission flags (user/group/other read/write/execute) with numeric constants instead, across the whole powerpc tree. Introducing a significant number of changes across the tree for no runtime benefit isn't exactly desirable, but so long as these macros are still used in the tree people will keep sending patches that add them. Not only are they hard to parse at a glance, there are multiple ways of coming to the same value (as you can see with 0444 and 0644 in this patch) which hurts readability. Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-21powerpc/pseries: Fix parent_dn reference leak in add_dt_node()Tyrel Datwyler1-1/+3
A reference to the parent device node is held by add_dt_node() for the node to be added. If the call to dlpar_configure_connector() fails add_dt_node() returns ENOENT and that reference is not freed. Add a call to of_node_put(parent_dn) prior to bailing out after a failed dlpar_configure_connector() call. Fixes: 8d5ff320766f ("powerpc/pseries: Make dlpar_configure_connector parent node aware") Cc: stable@vger.kernel.org # v3.12+ Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-23powerpc: pseries: remove dlpar_attach_node dependency on full pathRob Herring1-1/+1
In preparation to stop storing the full node path in full_name, remove the dependency on full_name from dlpar_attach_node(). Callers of dlpar_attach_node() already have the parent device_node, so just pass the parent node into dlpar_attach_node instead of the path. This avoids doing a lookup of the parent node by the path. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-07driver core: remove CLASS_ATTR usageGreg Kroah-Hartman1-3/+4
There was only 2 remaining users of CLASS_ATTR() so let's finally get rid of them and force everyone to use the correct RW/RO/WO versions instead. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-02powerpc/pseries: Update affinity for memory and cpus specified in a PRRN eventJohn Allen1-0/+34
Extend the existing PRRN infrastructure to perform the actual affinity updating for cpus and memory in addition to the device tree updating. For cpus, dynamic affinity updating already appears to exist in the kernel in the form of arch_update_cpu_topology(). For memory, we must place a READD operation on the hotplug queue for any phandle included in the PRRN event that is determined to be an LMB. Signed-off-by: John Allen <jallen@linux.vnet.ibm.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11powerpc: Update of_remove_property() call sites to remove null checkingSuraj Jitindar Singh1-2/+2
After obtaining a property from of_find_property() and before calling of_remove_property() most code checks to ensure that the property returned from of_find_property() is not null. The previous patch moved this check to the start of the function of_remove_property() in order to avoid the case where this check isn't done and a null value is passed. This ensures the check is always conducted before taking locks and attempting to remove the property. Thus it is no longer necessary to perform a check for null values before invoking of_remove_property(). Update of_remove_property() call sites in order to remove redundant checking for null property value as check is now performed within the of_remove_property function(). Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> [mpe: Unbreak some lines which are just >80 chars for readability] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>