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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
2022-03-08powerpc/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
2019-07-13Merge 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>
2018-01-22powerpc: 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>
2015-04-16Merge tag 'powerpc-4.1-1' of ↵Linus Torvalds1-7/+19
git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux Pull powerpc updates from Michael Ellerman: - Numerous minor fixes, cleanups etc. - More EEH work from Gavin to remove its dependency on device_nodes. - Memory hotplug implemented entirely in the kernel from Nathan Fontenot. - Removal of redundant CONFIG_PPC_OF by Kevin Hao. - Rewrite of VPHN parsing logic & tests from Greg Kurz. - A fix from Nish Aravamudan to reduce memory usage by clamping nodes_possible_map. - Support for pstore on powernv from Hari Bathini. - Removal of old powerpc specific byte swap routines by David Gibson. - Fix from Vasant Hegde to prevent the flash driver telling you it was flashing your firmware when it wasn't. - Patch from Ben Herrenschmidt to add an OPAL heartbeat driver. - Fix for an oops causing get/put_cpu_var() imbalance in perf by Jan Stancek. - Some fixes for migration from Tyrel Datwyler. - A new syscall to switch the cpu endian by Michael Ellerman. - Large series from Wei Yang to implement SRIOV, reviewed and acked by Bjorn. - A fix for the OPAL sensor driver from Cédric Le Goater. - Fixes to get STRICT_MM_TYPECHECKS building again by Michael Ellerman. - Large series from Daniel Axtens to make our PCI hooks per PHB rather than per machine. - Small patch from Sam Bobroff to explicitly abort non-suspended transactions on syscalls, plus a test to exercise it. - Numerous reworks and fixes for the 24x7 PMU from Sukadev Bhattiprolu. - Small patch to enable the hard lockup detector from Anton Blanchard. - Fix from Dave Olson for missing L2 cache information on some CPUs. - Some fixes from Michael Ellerman to get Cell machines booting again. - Freescale updates from Scott: Highlights include BMan device tree nodes, an MSI erratum workaround, a couple minor performance improvements, config updates, and misc fixes/cleanup. * tag 'powerpc-4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (196 commits) powerpc/powermac: Fix build error seen with powermac smp builds powerpc/pseries: Fix compile of memory hotplug without CONFIG_MEMORY_HOTREMOVE powerpc: Remove PPC32 code from pseries specific find_and_init_phbs() powerpc/cell: Fix iommu breakage caused by controller_ops change powerpc/eeh: Fix crash in eeh_add_device_early() on Cell powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH powerpc/perf/hv-24x7: Fail 24x7 initcall if create_events_from_catalog() fails powerpc/pseries: Correct memory hotplug locking powerpc: Fix missing L2 cache size in /sys/devices/system/cpu powerpc: Add ppc64 hard lockup detector support oprofile: Disable oprofile NMI timer on ppc64 powerpc/perf/hv-24x7: Add missing put_cpu_var() powerpc/perf/hv-24x7: Break up single_24x7_request powerpc/perf/hv-24x7: Define update_event_count() powerpc/perf/hv-24x7: Whitespace cleanup powerpc/perf/hv-24x7: Define add_event_to_24x7_request() powerpc/perf/hv-24x7: Rename hv_24x7_event_update powerpc/perf/hv-24x7: Move debug prints to separate function powerpc/perf/hv-24x7: Drop event_24x7_request() powerpc/perf/hv-24x7: Use pr_devel() to log message ... Conflicts: tools/testing/selftests/powerpc/Makefile tools/testing/selftests/powerpc/tm/Makefile
2015-03-28powerpc/pseries: Simplify check for suspendability during suspend/migrationTyrel Datwyler1-6/+3
During suspend/migration operation we must wait for the VASI state reported by the hypervisor to become Suspending prior to making the ibm,suspend-me RTAS call. Calling routines to rtas_ibm_supend_me() pass a vasi_state variable that exposes the VASI state to the caller. This is unnecessary as the caller only really cares about the following three conditions; if there is an error we should bailout, success indicating we have suspended and woken back up so proceed to device tree update, or we are not suspendable yet so try calling rtas_ibm_suspend_me again shortly. This patch removes the extraneous vasi_state variable and simply uses the return code to communicate how to proceed. We either succeed, fail, or get -EAGAIN in which case we sleep for a second before trying to call rtas_ibm_suspend_me again. The behaviour of ppc_rtas() remains the same, but migrate_store() now returns the propogated error code on failure. Previously -1 was returned from migrate_store() in the failure case which equates to -EPERM and was clearly wrong. Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Cc: Nathan Fontenont <nfont@linux.vnet.ibm.com> Cc: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-24powerpc/pseries: Introduce api_version to migration sysfs interfaceTyrel Datwyler1-1/+16
The /sys/kernel/mobility/migration interface was added all the way back in 2.6.37. However, the drmgr userspace tool was never augmented to use this interface to perfrom migrations. Instead it has continued using a faux rtas call coupled with performing the device tree update processing in userspace and communicating it back to the kernel via the ugly /proc/ppc64/ofdt interface. Up until 3.12 the device tree update code in the kernel was badly broken and bit rotting. This code was fixed in 3.12 and is now utilized by the kernel suspend code as of 3.15. The kernel is now better suited to handle the post-mobility fixup of the device tree and drmgr should be transitioned to using the sysfs migration interface. This patch introduces the api_version sysfs file to /sys/kernel/mobility as a means for drmgr to query the current implementation level of the kernel migration code. This initial versioning indicates it is capable of perfroming all current PAPR requirements for migration including the post-mobility firmware activation and device tree update. Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-20powerpc/pseries: Little endian fixes for post mobility device tree updateTyrel Datwyler1-21/+23
We currently use the device tree update code in the kernel after resuming from a suspend operation to re-sync the kernels view of the device tree with that of the hypervisor. The code as it stands is not endian safe as it relies on parsing buffers returned by RTAS calls that thusly contains data in big endian format. This patch annotates variables and structure members with __be types as well as performing necessary byte swaps to cpu endian for data that needs to be parsed. Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Cyril Bur <cyrilbur@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-27powerpc/pseries: Fix endian problems with LE migrationCyril Bur1-16/+6
RTAS events require arguments be passed in big endian while hypercalls have their arguments passed in registers and the values should therefore be in CPU endian. The "ibm,suspend_me" 'RTAS' call makes a sequence of hypercalls to setup one true RTAS call. This means that "ibm,suspend_me" is handled specially in the ppc_rtas() syscall. The ppc_rtas() syscall has its arguments in big endian and can therefore pass these arguments directly to the RTAS call. "ibm,suspend_me" is handled specially from within ppc_rtas() (by calling rtas_ibm_suspend_me()) which has left an endian bug on little endian systems due to the requirement of hypercalls. The return value from rtas_ibm_suspend_me() gets returned in cpu endian, and is left unconverted, also a bug on little endian systems. rtas_ibm_suspend_me() does not actually make use of the rtas_args that it is passed. This patch removes the convoluted use of the rtas_args struct to pass params to rtas_ibm_suspend_me() in favour of passing what it needs as actual arguments. This patch also ensures the two callers of rtas_ibm_suspend_me() pass function parameters in cpu endian and in the case of ppc_rtas(), converts the return value. migrate_store() (the other caller of rtas_ibm_suspend_me()) is from a sysfs file which deals with everything in cpu endian so this function only underwent cleanup. This patch has been tested with KVM both LE and BE and on PowerVM both LE and BE. Under QEMU/KVM the migration happens without touching these code pathes. For PowerVM there is no obvious regression on BE and the LE code path now provides the correct parameters to the hypervisor. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-08-08arch/powerpc: replace obsolete strict_strto* callsDaniel Walter1-1/+1
Replace strict_strto calls with more appropriate kstrto calls Signed-off-by: Daniel Walter <dwalter@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-28powerpc/pseries: Switch pseries drivers to use machine_xxx_initcall()Michael Ellerman1-1/+2
A lot of the code in platforms/pseries is using non-machine initcalls. That means if a kernel built with pseries support runs on another platform, for example powernv, the initcalls will still run. Most of these cases are OK, though sometimes only due to luck. Some were having more effect: * hcall_inst_init - Checking FW_FEATURE_LPAR which is set on ps3 & celleb. * mobility_sysfs_init - created sysfs files unconditionally - but no effect due to ENOSYS from rtas_ibm_suspend_me() * apo_pm_init - created sysfs, allows write - nothing checks the value written to though * alloc_dispatch_log_kmem_cache - creating kmem_cache on non-pseries machines Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>