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2017-10-19powerpc: make dma_cache_sync a no-opChristoph Hellwig
powerpc does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't make any sense to do any work in dma_cache_sync given that it must be a no-op when dma_alloc_attrs returns coherent memory. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2017-10-19floppy: consolidate the dummy fd_cacheflush definitionChristoph Hellwig
Only mips defines this helper, so remove all the other arch definitions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2017-10-13Merge tag 'powerpc-4.14-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "A fix for a bad bug (written by me) in our livepatch handler. Removal of an over-zealous lockdep_assert_cpus_held() in our topology code. A fix to the recently added emulation of cntlz[wd]. And three small fixes to the recently added IMC PMU driver. Thanks to: Anju T Sudhakar, Balbir Singh, Kamalesh Babulal, Naveen N. Rao, Sandipan Das, Santosh Sivaraj, Thiago Jung Bauermann" * tag 'powerpc-4.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/perf: Fix IMC initialization crash powerpc/perf: Add ___GFP_NOWARN flag to alloc_pages_node() powerpc/perf: Fix for core/nest imc call trace on cpuhotplug powerpc: Don't call lockdep_assert_cpus_held() from arch_update_cpu_topology() powerpc/lib/sstep: Fix count leading zeros instructions powerpc/livepatch: Fix livepatch stack access
2017-10-13powerpc/perf: Fix IMC initialization crashAnju T Sudhakar
Panic observed with latest firmware, and upstream kernel: NIP init_imc_pmu+0x8c/0xcf0 LR init_imc_pmu+0x2f8/0xcf0 Call Trace: init_imc_pmu+0x2c8/0xcf0 (unreliable) opal_imc_counters_probe+0x300/0x400 platform_drv_probe+0x64/0x110 driver_probe_device+0x3d8/0x580 __driver_attach+0x14c/0x1a0 bus_for_each_dev+0x8c/0xf0 driver_attach+0x34/0x50 bus_add_driver+0x298/0x350 driver_register+0x9c/0x180 __platform_driver_register+0x5c/0x70 opal_imc_driver_init+0x2c/0x40 do_one_initcall+0x64/0x1d0 kernel_init_freeable+0x280/0x374 kernel_init+0x24/0x160 ret_from_kernel_thread+0x5c/0x74 While registering nest imc at init, cpu-hotplug callback nest_pmu_cpumask_init() makes an OPAL call to stop the engine. And if the OPAL call fails, imc_common_cpuhp_mem_free() is invoked to cleanup memory and cpuhotplug setup. But when cleaning up the attribute group, we are dereferencing the attribute element array without checking whether the backing element is not NULL. This causes the kernel panic. Add a check for the backing element prior to dereferencing the attribute element, to handle the failing case gracefully. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reported-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com> [mpe: Trim change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-12powerpc/perf: Add ___GFP_NOWARN flag to alloc_pages_node()Anju T Sudhakar
Stack trace output during a stress test: [ 4.310049] Freeing initrd memory: 22592K [ 4.310646] rtas_flash: no firmware flash support [ 4.313341] cpuhp/64: page allocation failure: order:0, mode:0x14480c0(GFP_KERNEL|__GFP_ZERO|__GFP_THISNODE), nodemask=(null) [ 4.313465] cpuhp/64 cpuset=/ mems_allowed=0 [ 4.313521] CPU: 64 PID: 392 Comm: cpuhp/64 Not tainted 4.11.0-39.el7a.ppc64le #1 [ 4.313588] Call Trace: [ 4.313622] [c000000f1fb1b8e0] [c000000000c09388] dump_stack+0xb0/0xf0 (unreliable) [ 4.313694] [c000000f1fb1b920] [c00000000030ef6c] warn_alloc+0x12c/0x1c0 [ 4.313753] [c000000f1fb1b9c0] [c00000000030ff68] __alloc_pages_nodemask+0xea8/0x1000 [ 4.313823] [c000000f1fb1bbb0] [c000000000113a8c] core_imc_mem_init+0xbc/0x1c0 [ 4.313892] [c000000f1fb1bc00] [c000000000113cdc] ppc_core_imc_cpu_online+0x14c/0x170 [ 4.313962] [c000000f1fb1bc90] [c000000000125758] cpuhp_invoke_callback+0x198/0x5d0 [ 4.314031] [c000000f1fb1bd00] [c00000000012782c] cpuhp_thread_fun+0x8c/0x3d0 [ 4.314101] [c000000f1fb1bd60] [c0000000001678d0] smpboot_thread_fn+0x290/0x2a0 [ 4.314169] [c000000f1fb1bdc0] [c00000000015ee78] kthread+0x168/0x1b0 [ 4.314229] [c000000f1fb1be30] [c00000000000b368] ret_from_kernel_thread+0x5c/0x74 [ 4.314313] Mem-Info: [ 4.314356] active_anon:0 inactive_anon:0 isolated_anon:0 core_imc_mem_init() at system boot use alloc_pages_node() to get memory and alloc_pages_node() throws this stack dump when tried to allocate memory from a node which has no memory behind it. Add a ___GFP_NOWARN flag in allocation request as a fix. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Venkat R.B <venkatb3@in.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-12powerpc/perf: Fix for core/nest imc call trace on cpuhotplugAnju T Sudhakar
Nest/core pmu units are enabled only when it is used. A reference count is maintained for the events which uses the nest/core pmu units. Currently in *_imc_counters_release function a WARN() is used for notification of any underflow of ref count. The case where event ref count hit a negative value is, when perf session is started, followed by offlining of all cpus in a given core. i.e. in cpuhotplug offline path ppc_core_imc_cpu_offline() function set the ref->count to zero, if the current cpu which is about to offline is the last cpu in a given core and make an OPAL call to disable the engine in that core. And on perf session termination, perf->destroy (core_imc_counters_release) will first decrement the ref->count for this core and based on the ref->count value an opal call is made to disable the core-imc engine. Now, since cpuhotplug path already clears the ref->count for core and disabled the engine, perf->destroy() decrementing again at event termination make it negative which in turn fires the WARN_ON. The same happens for nest units. Add a check to see if the reference count is alreday zero, before decrementing the count, so that the ref count will not hit a negative value. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reviewed-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-10powerpc: Don't call lockdep_assert_cpus_held() from arch_update_cpu_topology()Thiago Jung Bauermann
It turns out that not all paths calling arch_update_cpu_topology() hold cpu_hotplug_lock, but that's OK because those paths can't race with any concurrent hotplug events. Warnings were reported with the following trace: lockdep_assert_cpus_held arch_update_cpu_topology sched_init_domains sched_init_smp kernel_init_freeable kernel_init ret_from_kernel_thread Which is safe because it's called early in boot when hotplug is not live yet. And also this trace: lockdep_assert_cpus_held arch_update_cpu_topology partition_sched_domains cpuset_update_active_cpus sched_cpu_deactivate cpuhp_invoke_callback cpuhp_down_callbacks cpuhp_thread_fun smpboot_thread_fn kthread ret_from_kernel_thread Which is safe because it's called as part of CPU hotplug, so although we don't hold the CPU hotplug lock, there is another thread driving the CPU hotplug operation which does hold the lock, and there is no race. Thanks to tglx for deciphering it for us. Fixes: 3e401f7a2e51 ("powerpc: Only obtain cpu_hotplug_lock if called by rtasd") Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-10powerpc/lib/sstep: Fix count leading zeros instructionsSandipan Das
According to the GCC documentation, the behaviour of __builtin_clz() and __builtin_clzl() is undefined if the value of the input argument is zero. Without handling this special case, these builtins have been used for emulating the following instructions: * Count Leading Zeros Word (cntlzw[.]) * Count Leading Zeros Doubleword (cntlzd[.]) This fixes the emulated behaviour of these instructions by adding an additional check for this special case. Fixes: 3cdfcbfd32b9d ("powerpc: Change analyse_instr so it doesn't modify *regs") Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-10powerpc/livepatch: Fix livepatch stack accessKamalesh Babulal
While running stress test with livepatch module loaded, kernel bug was triggered. cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60] 5:mon> t [c0000000eb9d3de0] c0000000eb9d3e30 (unreliable) [c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120 --- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74 [c0000000eb9d4120] 0000000057ac6e9d (unreliable) [d0000000089d9f78] 2e0965747962382e SP (965747962342e09) is in userspace When an interrupt occurs during the livepatch_handler execution, it's possible for the livepatch_stack and/or thread_info to be corrupted. eg: Task A Interrupt Handler ========= ================= livepatch_handler: mr r0, r1 ld r1, TI_livepatch_sp(r12) hardware_interrupt_common: do_IRQ+0x8: mflr r0 <- saved stack pointer is overwritten bl _mcount ... std r27,-40(r1) <- overwrite of thread_info() lis r2, STACK_END_MAGIC@h ori r2, r2, STACK_END_MAGIC@l ld r12, -8(r1) Fix the corruption by using r11 register for livepatch stack manipulation, instead of shuffling task stack and livepatch stack into r1 register. Using r11 register also avoids disabling/enabling irq's while setting up the livepatch stack. Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-09Merge branch 'ppc-bundle' (bundle from Michael Ellerman)Linus Torvalds
Merge powerpc transactional memory fixes from Michael Ellerman: "I figured I'd still send you the commits using a bundle to make sure it works in case I need to do it again in future" This fixes transactional memory state restore for powerpc. * bundle'd patches from Michael Ellerman: powerpc/tm: Fix illegal TM state in signal handler powerpc/64s: Use emergency stack for kernel TM Bad Thing program checks
2017-10-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Radim Krčmář: - fix PPC XIVE interrupt delivery - fix x86 RCU breakage from asynchronous page faults when built without PREEMPT_COUNT - fix x86 build with -frecord-gcc-switches - fix x86 build without X86_LOCAL_APIC * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: add X86_LOCAL_APIC dependency x86/kvm: Move kvm_fastop_exception to .fixup section kvm/x86: Avoid async PF preempting the kernel incorrectly KVM: PPC: Book3S: Fix server always zero from kvmppc_xive_get_xive()
2017-10-06Merge tag 'powerpc-4.14-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Nine small fixes, really nothing that stands out. A work-around for a spurious MCE on Power9. A CXL fault handling fix, some fixes to the new XIVE code, and a fix to the new 32-bit STRICT_KERNEL_RWX code. Fixes for old code/stable: an fix to an incorrect TLB flush on boot but not on any current machines, a compile error on 4xx and a fix to memory hotplug when using radix (Power9). Thanks to: Anton Blanchard, Cédric Le Goater, Christian Lamparter, Christophe Leroy, Christophe Lombard, Guenter Roeck, Jeremy Kerr, Michael Neuling, Nicholas Piggin" * tag 'powerpc-4.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/powernv: Increase memory block size to 1GB on radix powerpc/mm: Call flush_tlb_kernel_range with interrupts enabled powerpc/xive: Clear XIVE internal structures when a CPU is removed powerpc/xive: Fix IPI reset powerpc/4xx: Fix compile error with 64K pages on 40x, 44x powerpc: Fix action argument for cpufeatures-based TLB flush cxl: Fix memory page not handled powerpc: Fix workaround for spurious MCE on POWER9 powerpc: Handle MCE on POWER9 with only DSISR bit 30 set
2017-10-06Merge branch 'core-watchdog-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull watchddog clean-up and fixes from Thomas Gleixner: "The watchdog (hard/softlockup detector) code is pretty much broken in its current state. The patch series addresses this by removing all duct tape and refactoring it into a workable state. The reasons why I ask for inclusion that late in the cycle are: 1) The code causes lockdep splats vs. hotplug locking which get reported over and over. Unfortunately there is no easy fix. 2) The risk of breakage is minimal because it's already broken 3) As 4.14 is a long term stable kernel, I prefer to have working watchdog code in that and the lockdep issues resolved. I wouldn't ask you to pull if 4.14 wouldn't be a LTS kernel or if the solution would be easy to backport. 4) The series was around before the merge window opened, but then got delayed due to the UP failure caused by the for_each_cpu() surprise which we discussed recently. Changes vs. V1: - Addressed your review points - Addressed the warning in the powerpc code which was discovered late - Changed two function names which made sense up to a certain point in the series. Now they match what they do in the end. - Fixed a 'unused variable' warning, which got not detected by the intel robot. I triggered it when trying all possible related config combinations manually. Randconfig testing seems not random enough. The changes have been tested by and reviewed by Don Zickus and tested and acked by Micheal Ellerman for powerpc" * 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) watchdog/core: Put softlockup_threads_initialized under ifdef guard watchdog/core: Rename some softlockup_* functions powerpc/watchdog: Make use of watchdog_nmi_probe() watchdog/core, powerpc: Lock cpus across reconfiguration watchdog/core, powerpc: Replace watchdog_nmi_reconfigure() watchdog/hardlockup/perf: Fix spelling mistake: "permanetely" -> "permanently" watchdog/hardlockup/perf: Cure UP damage watchdog/hardlockup: Clean up hotplug locking mess watchdog/hardlockup/perf: Simplify deferred event destroy watchdog/hardlockup/perf: Use new perf CPU enable mechanism watchdog/hardlockup/perf: Implement CPU enable replacement watchdog/hardlockup/perf: Implement init time detection of perf watchdog/hardlockup/perf: Implement init time perf validation watchdog/core: Get rid of the racy update loop watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage watchdog/sysctl: Clean up sysctl variable name space watchdog/sysctl: Get rid of the #ifdeffery watchdog/core: Clean up header mess watchdog/core: Further simplify sysctl handling watchdog/core: Get rid of the thread teardown/setup dance ...
2017-10-06powerpc/tm: Fix illegal TM state in signal handlerGustavo Romero
Currently it's possible that on returning from the signal handler through the restore_tm_sigcontexts() code path (e.g. from a signal caught due to a `trap` instruction executed in the middle of an HTM block, or a deliberately constructed sigframe) an illegal TM state (like TS=10 TM=0, i.e. "T0") is set in SRR1 and when `rfid` sets implicitly the MSR register from SRR1 register on return to userspace it causes a TM Bad Thing exception. That illegal state can be set (a) by a malicious user that disables the TM bit by tweaking the bits in uc_mcontext before returning from the signal handler or (b) by a sufficient number of context switches occurring such that the load_tm counter overflows and TM is disabled whilst in the signal handler. This commit fixes the illegal TM state by ensuring that TM bit is always enabled before we return from restore_tm_sigcontexts(). A small comment correction is made as well. Fixes: 5d176f751ee3 ("powerpc: tm: Enable transactional memory (TM) lazily for userspace") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-06powerpc/64s: Use emergency stack for kernel TM Bad Thing program checksCyril Bur
When using transactional memory (TM), the CPU can be in one of six states as far as TM is concerned, encoded in the Machine State Register (MSR). Certain state transitions are illegal and if attempted trigger a "TM Bad Thing" type program check exception. If we ever hit one of these exceptions it's treated as a bug, ie. we oops, and kill the process and/or panic, depending on configuration. One case where we can trigger a TM Bad Thing, is when returning to userspace after a system call or interrupt, using RFID. When this happens the CPU first restores the user register state, in particular r1 (the stack pointer) and then attempts to update the MSR. However the MSR update is not allowed and so we take the program check with the user register state, but the kernel MSR. This tricks the exception entry code into thinking we have a bad kernel stack pointer, because the MSR says we're coming from the kernel, but r1 is pointing to userspace. To avoid this we instead always switch to the emergency stack if we take a TM Bad Thing from the kernel. That way none of the user register values are used, other than for printing in the oops message. This is the fix for CVE-2017-1000255. Fixes: 5d176f751ee3 ("powerpc: tm: Enable transactional memory (TM) lazily for userspace") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Rewrite change log & comments, tweak asm slightly] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-06powerpc/powernv: Increase memory block size to 1GB on radixAnton Blanchard
Memory hot unplug on PowerNV radix hosts is broken. Our memory block size is 256MB but since we map the linear region with very large pages, each pte we tear down maps 1GB. A hot unplug of one 256MB memory block results in 768MB of memory getting unintentionally unmapped. At this point we are likely to oops. Fix this by increasing our memory block size to 1GB on PowerNV radix hosts. Fixes: 4b5d62ca17a1 ("powerpc/mm: add radix__remove_section_mapping()") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/mm: Call flush_tlb_kernel_range with interrupts enabledGuenter Roeck
flush_tlb_kernel_range() may call smp_call_function_many() which expects interrupts to be enabled. This results in a traceback. WARNING: CPU: 0 PID: 1 at kernel/smp.c:416 smp_call_function_many+0xcc/0x2fc CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc1-00009-g0666f56 #1 task: cf830000 task.stack: cf82e000 NIP: c00a93c8 LR: c00a9634 CTR: 00000001 REGS: cf82fde0 TRAP: 0700 Not tainted (4.14.0-rc1-00009-g0666f56) MSR: 00021000 <CE,ME> CR: 24000082 XER: 00000000 GPR00: c00a9634 cf82fe90 cf830000 c050ad3c c0015a54 00000000 00000001 00000001 GPR08: 00000001 00000000 00000000 cf82e000 24000084 00000000 c0003150 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000001 00000000 c0510000 GPR24: 00000000 c0015a54 00000000 c050ad3c c051823c c050ad3c 00000025 00000000 NIP [c00a93c8] smp_call_function_many+0xcc/0x2fc LR [c00a9634] smp_call_function+0x3c/0x50 Call Trace: [cf82fe90] [00000010] 0x10 (unreliable) [cf82fed0] [c00a9634] smp_call_function+0x3c/0x50 [cf82fee0] [c0015d2c] flush_tlb_kernel_range+0x20/0x38 [cf82fef0] [c001524c] mark_initmem_nx+0x154/0x16c [cf82ff20] [c001484c] free_initmem+0x20/0x4c [cf82ff30] [c000316c] kernel_init+0x1c/0x108 [cf82ff40] [c000f3a8] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7c0803a6 7d808120 38210040 4e800020 3d20c052 812981a0 2f890000 40beffac 3d20c051 8929ac64 2f890000 40beff9c <0fe00000> 4bffff94 7fc3f378 7f64db78 Fixes: 3184cc4b6f6a ("powerpc/mm: Fix kernel RAM protection after freeing ...") Fixes: e611939fc8ec ("powerpc/mm: Ensure change_page_attr() doesn't ...") Cc: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/xive: Clear XIVE internal structures when a CPU is removedCédric Le Goater
Commit eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") introduced support for the XIVE exploitation mode of the P9 interrupt controller on the pseries platform. At that time, support for CPU removal was not complete on PowerVM and CPU hot unplug remained untested. It appears that some cleanups of the XIVE internal structures are required before releasing the CPU, without which the kernel crashes in a RTAS call doing the CPU isolation. These changes fix the crash by deconfiguring the IPI interrupt source and clearing the event queues of the CPU when it is removed. Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/xive: Fix IPI resetCédric Le Goater
When resetting an IPI, hw_ipi should also be set to zero. Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/watchdog: Make use of watchdog_nmi_probe()Thomas Gleixner
The rework of the core hotplug code triggers the WARN_ON in start_wd_cpu() on powerpc because it is called multiple times for the boot CPU. The first call is via: start_wd_on_cpu+0x80/0x2f0 watchdog_nmi_reconfigure+0x124/0x170 softlockup_reconfigure_threads+0x110/0x130 lockup_detector_init+0xbc/0xe0 kernel_init_freeable+0x18c/0x37c kernel_init+0x2c/0x160 ret_from_kernel_thread+0x5c/0xbc And then again via the CPU hotplug registration: start_wd_on_cpu+0x80/0x2f0 cpuhp_invoke_callback+0x194/0x620 cpuhp_thread_fun+0x7c/0x1b0 smpboot_thread_fn+0x290/0x2a0 kthread+0x168/0x1b0 ret_from_kernel_thread+0x5c/0xbc This can be avoided by setting up the cpu hotplug state with nocalls and move the initialization to the watchdog_nmi_probe() function. That initializes the hotplug callbacks without invoking the callback and the following core initialization function then configures the watchdog for the online CPUs (in this case CPU0) via softlockup_reconfigure_threads(). Reported-and-tested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org
2017-10-04watchdog/core, powerpc: Lock cpus across reconfigurationThomas Gleixner
Instead of dropping the cpu hotplug lock after stopping NMI watchdog and threads and reaquiring for restart, the code and the protection rules become more obvious when holding cpu hotplug lock across the full reconfiguration. Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Don Zickus <dzickus@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710022105570.2114@nanos
2017-10-04watchdog/core, powerpc: Replace watchdog_nmi_reconfigure()Thomas Gleixner
The recent cleanup of the watchdog code split watchdog_nmi_reconfigure() into two stages. One to stop the NMI and one to restart it after reconfiguration. That was done by adding a boolean 'run' argument to the code, which is functionally correct but not necessarily a piece of art. Replace it by two explicit functions: watchdog_nmi_stop() and watchdog_nmi_start(). Fixes: 6592ad2fcc8f ("watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage") Requested-by: Linus 'Nursing his pet-peeve' Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Thomas 'Mopping up garbage' Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Don Zickus <dzickus@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710021957480.2114@nanos
2017-10-03rapidio: remove global irq spinlocks from the subsystemIoan Nicu
Locking of config and doorbell operations should be done only if the underlying hardware requires it. This patch removes the global spinlocks from the rapidio subsystem and moves them to the mport drivers (fsl_rio and tsi721), only to the necessary places. For example, local config space read and write operations (lcread/lcwrite) are atomic in all existing drivers, so there should be no need for locking, while the cread/cwrite operations which generate maintenance transactions need to be synchronized with a lock. Later, each driver could chose to use a per-port lock instead of a global one, or even more granular locking. Link: http://lkml.kernel.org/r/20170824113023.GD50104@nokia.com Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com> Signed-off-by: Frank Kunz <frank.kunz@nokia.com> Acked-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03KVM: PPC: Book3S: Fix server always zero from kvmppc_xive_get_xive()Sam Bobroff
In KVM's XICS-on-XIVE emulation, kvmppc_xive_get_xive() returns the value of state->guest_server as "server". However, this value is not set by it's counterpart kvmppc_xive_set_xive(). When the guest uses this interface to migrate interrupts away from a CPU that is going offline, it sees all interrupts as belonging to CPU 0, so they are left assigned to (now) offline CPUs. This patch removes the guest_server field from the state, and returns act_server in it's place (that is, the CPU actually handling the interrupt, which may differ from the one requested). Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Cc: stable@vger.kernel.org Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-10-03powerpc/4xx: Fix compile error with 64K pages on 40x, 44xChristian Lamparter
The mmu context on the 40x, 44x does not define pte_frag entry. This causes gcc abort the compilation due to: setup-common.c: In function ‘setup_arch’: setup-common.c:908: error: ‘mm_context_t’ has no ‘pte_frag’ This patch fixes the issue by removing the pte_frag initialization in setup-common.c. This is possible, because the compiler will do the initialization, since the mm_context is a sub struct of init_mm. init_mm is declared in mm_types.h as external linkage. According to C99 6.2.4.3: An object whose identifier is declared with external linkage [...] has static storage duration. C99 defines in 6.7.8.10 that: If an object that has static storage duration is not initialized explicitly, then: - if it has pointer type, it is initialized to a null pointer Fixes: b1923caa6e64 ("powerpc: Merge 32-bit and 64-bit setup_arch()") Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-03powerpc: Fix action argument for cpufeatures-based TLB flushJeremy Kerr
Commit 41d0c2ecde19 ("powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9") introduced calls to __flush_tlb_power[89] from the cpufeatures code, specifying the number of sets to flush. However, these functions take an action argument, not a number of sets. This means we hit the BUG() in __flush_tlb_{206,300} when using cpufeatures-style configuration. This change passes TLB_INVAL_SCOPE_GLOBAL instead. Fixes: 41d0c2ecde19 ("powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "Mixed bugfixes. Perhaps the most interesting one is a latent bug that was finally triggered by PCID support" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm/x86: Handle async PF in RCU read-side critical sections KVM: nVMX: Fix nested #PF intends to break L1's vmlauch/vmresume KVM: VMX: use cmpxchg64 KVM: VMX: simplify and fix vmx_vcpu_pi_load KVM: VMX: avoid double list add with VT-d posted interrupts KVM: VMX: extract __pi_post_block KVM: PPC: Book3S HV: Check for updated HDSISR on P9 HDSI exception KVM: nVMX: fix HOST_CR3/HOST_CR4 cache
2017-09-29powerpc: Fix workaround for spurious MCE on POWER9Michael Neuling
In the recent commit d8bd9f3f0925 ("powerpc: Handle MCE on POWER9 with only DSISR bit 30 set") I screwed up the bit number. It should be bit 25 (IBM bit 38). Fixes: d8bd9f3f0925 ("powerpc: Handle MCE on POWER9 with only DSISR bit 30 set") Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-26powerpc: Handle MCE on POWER9 with only DSISR bit 30 setMichael Neuling
On POWER9 DD2.1 and below, it's possible for a paste instruction to cause a Machine Check Exception (MCE) where only DSISR bit 30 (IBM 33) is set. This will result in the MCE handler seeing an unknown event, which triggers linux to crash. We change this by detecting unknown events caused by load/stores in the MCE handler and marking them as handled so that we no longer crash. An MCE that occurs like this is spurious, so we don't need to do anything in terms of servicing it. If there is something that needs to be serviced, the CPU will raise the MCE again with the correct DSISR so that it can be serviced properly. Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com Acked-by: Balbir Singh <bsingharora@gmail.com> [mpe: Expand comment with details from change log, use normal bit #s] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-22KVM: PPC: Book3S HV: Check for updated HDSISR on P9 HDSI exceptionMichael Neuling
On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage Interrupt (HDSI) the HDSISR is not be updated at all. To work around this we put a canary value into the HDSISR before returning to a guest and then check for this canary when we take a HDSI. If we find the canary on a HDSI, we know the hardware didn't update the HDSISR. In this case we return to the guest to retake the HDSI which should correctly update the HDSISR the second time HDSI entry. After talking to Paulus we've applied this workaround to all POWER9 CPUs. The workaround of returning to the guest shouldn't ever be triggered on well behaving CPU. The extra instructions should have negligible performance impact. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-21powerpc/pseries: Fix parent_dn reference leak in add_dt_node()Tyrel Datwyler
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>
2017-09-21powerpc/pseries: Fix "OF: ERROR: Bad of_node_put() on /cpus" during DLPARTyrel Datwyler
Commit 215ee763f8cb ("powerpc: pseries: remove dlpar_attach_node dependency on full path") reworked dlpar_attach_node() to no longer look up the parent node "/cpus", but instead to have the parent node passed by the caller in the function parameter list. As a result dlpar_attach_node() is no longer responsible for freeing the reference to the parent node. However, commit 215ee763f8cb failed to remove the of_node_put(parent) call in dlpar_attach_node(), or to take into account that the reference to the parent in the caller dlpar_cpu_add() needs to be held until after dlpar_attach_node() returns. As a result doing repeated cpu add/remove dlpar operations will eventually result in the following error: OF: ERROR: Bad of_node_put() on /cpus CPU: 0 PID: 10896 Comm: drmgr Not tainted 4.13.0-autotest #1 Call Trace: dump_stack+0x15c/0x1f8 (unreliable) of_node_release+0x1a4/0x1c0 kobject_put+0x1a8/0x310 kobject_del+0xbc/0xf0 __of_detach_node_sysfs+0x144/0x210 of_detach_node+0xf0/0x180 dlpar_detach_node+0xc4/0x120 dlpar_cpu_remove+0x280/0x560 dlpar_cpu_release+0xbc/0x1b0 arch_cpu_release+0x6c/0xb0 cpu_release_store+0xa0/0x100 dev_attr_store+0x68/0xa0 sysfs_kf_write+0xa8/0xf0 kernfs_fop_write+0x2cc/0x400 __vfs_write+0x5c/0x340 vfs_write+0x1a8/0x3d0 SyS_write+0xa8/0x1a0 system_call+0x58/0x6c Fix the issue by removing the of_node_put(parent) call from dlpar_attach_node(), and ensuring that the reference to the parent node is properly held and released by the caller dlpar_cpu_add(). Fixes: 215ee763f8cb ("powerpc: pseries: remove dlpar_attach_node dependency on full path") Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> [mpe: Add a comment in the code and frob the change log slightly] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-21powerpc/eeh: Create PHB PEs after EEH is initializedBenjamin Herrenschmidt
Otherwise we end up not yet having computed the right diag data size on powernv where EEH initialization is delayed, thus causing memory corruption later on when calling OPAL. Fixes: 5cb1f8fdddb7 ("powerpc/powernv/pci: Dynamically allocate PHB diag data") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/kprobes: Update optprobes to use emulate_update_regs()Naveen N. Rao
Optprobes depended on an updated regs->nip from analyse_instr() to identify the location to branch back from the optprobes trampoline. However, since commit 3cdfcbfd32b9d ("powerpc: Change analyse_instr so it doesn't modify *regs"), analyse_instr() doesn't update the registers anymore. Due to this, we end up branching back from the optprobes trampoline to the same branch into the trampoline resulting in a loop. Fix this by calling out to emulate_update_regs() before using the nip. Additionally, explicitly compare the return value from analyse_instr() to 1, rather than just checking for !0 so as to guard against any future changes to analyse_instr() that may result in -1 being returned in more scenarios. Fixes: 3cdfcbfd32b9d ("powerpc: Change analyse_instr so it doesn't modify *regs") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20Merge branch 'next' of ↵Michael Ellerman
git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into fixes Merge one commit from Scott which I missed while away.
2017-09-20powerpc/powernv: Clear LPCR[PECE1] via stop-api only for deep state offlineGautham R. Shenoy
Commit 24be85a23d1f ("powerpc/powernv: Clear PECE1 in LPCR via stop-api only on Hotplug") clears the PECE1 bit of the LPCR via stop-api during CPU-Hotplug to prevent wakeup due to a decrementer on an offlined CPU which is in a deep stop state. In the case where the stop-api support is found to be lacking, the commit 785a12afdb4a ("powerpc/powernv/idle: Disable LOSE_FULL_CONTEXT states when stop-api fails") disables deep states that lose hypervisor context. Thus in this case, the offlined CPU will be put to some shallow idle state. However, we currently unconditionally clear the PECE1 in LPCR via stop-api during CPU-Hotplug even when deep states are disabled due to stop-api failure. Fix this by clearing PECE1 of LPCR via stop-api during CPU-Hotplug *only* when the offlined CPU will be put to a deep state that loses hypervisor context. Fixes: 24be85a23d1f ("powerpc/powernv: Clear PECE1 in LPCR via stop-api only on Hotplug") Reported-by: Pavithra Prakash <pavirampu@linux.vnet.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Pavithra Prakash <pavrampu@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/sstep: mullw should calculate a 64 bit signed resultAnton Blanchard
mullw should do a 32 bit signed multiply and create a 64 bit signed result. It currently truncates the result to 32 bits. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/sstep: Fix issues with mcrfAnton Blanchard
mcrf broke when we changed analyse_instr() to not modify the register state. The instruction writes to the CR, so we need to store the result in op->ccval, not op->val. Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs") Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/sstep: Fix issues with set_cr0()Anton Blanchard
set_cr0() broke when we changed analyse_instr() to not modify the register state. Instead of looking at regs->gpr[x] which has not been updated yet, we need to look at op->val. Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs") Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/tm: Flush TM only if CPU has TM featureGustavo Romero
Commit cd63f3c ("powerpc/tm: Fix saving of TM SPRs in core dump") added code to access TM SPRs in flush_tmregs_to_thread(). However flush_tmregs_to_thread() does not check if TM feature is available on CPU before trying to access TM SPRs in order to copy live state to thread structures. flush_tmregs_to_thread() is indeed guarded by CONFIG_PPC_TRANSACTIONAL_MEM but it might be the case that kernel was compiled with CONFIG_PPC_TRANSACTIONAL_MEM enabled and ran on a CPU without TM feature available, thus rendering the execution of TM instructions that are treated by the CPU as illegal instructions. The fix is just to add proper checking in flush_tmregs_to_thread() if CPU has the TM feature before accessing any TM-specific resource, returning immediately if TM is no available on the CPU. Adding that checking in flush_tmregs_to_thread() instead of in places where it is called, like in vsr_get() and vsr_set(), is better because avoids the same problem cropping up elsewhere. Cc: stable@vger.kernel.org # v4.13+ Fixes: cd63f3c ("powerpc/tm: Fix saving of TM SPRs in core dump") Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/sysrq: Fix oops whem ppmu is not registeredRavi Bangoria
Kernel crashes if power pmu is not registered and user tries to dump regs with 'echo p > /proc/sysrq-trigger'. Sample log: Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000000d52f0 NIP [c0000000000d52f0] perf_event_print_debug+0x10/0x230 LR [c00000000058a938] sysrq_handle_showregs+0x38/0x50 Call Trace: printk+0x38/0x4c (unreliable) __handle_sysrq+0xe4/0x270 write_sysrq_trigger+0x64/0x80 proc_reg_write+0x80/0xd0 __vfs_write+0x40/0x200 vfs_write+0xc8/0x240 SyS_write+0x60/0x110 system_call+0x58/0x6c Fixes: 5f6d0380c640 ("powerpc/perf: Define perf_event_print_debug() to print PMU register values") Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20powerpc/configs: Update for CONFIG_SND changesMichael Ellerman
Commit eb3b705aaed9 ("ALSA: Make CONFIG_SND_OSSEMUL user-selectable") means we need to set CONFIG_SND_OSSEMUL in our configs, otherwise we lose some of the SND symbols. And commit 0181307abc1d ("ALSA: seq: Reorganize kconfig and build") reorganised things, which causes the churn. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull more KVM updates from Paolo Bonzini: - PPC bugfixes - RCU splat fix - swait races fix - pointless userspace-triggerable BUG() fix - misc fixes for KVM_RUN corner cases - nested virt correctness fixes + one host DoS - some cleanups - clang build fix - fix AMD AVIC with default QEMU command line options - x86 bugfixes * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits) kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly kvm: vmx: Handle VMLAUNCH/VMRESUME failure properly kvm: nVMX: Remove nested_vmx_succeed after successful VM-entry kvm,mips: Fix potential swait_active() races kvm,powerpc: Serialize wq active checks in ops->vcpu_kick kvm: Serialize wq active checks in kvm_vcpu_wake_up() kvm,x86: Fix apf_task_wake_one() wq serialization kvm,lapic: Justify use of swait_active() kvm,async_pf: Use swq_has_sleeper() sched/wait: Add swq_has_sleeper() KVM: VMX: Do not BUG() on out-of-bounds guest IRQ KVM: Don't accept obviously wrong gsi values via KVM_IRQFD kvm: nVMX: Don't allow L2 to access the hardware CR8 KVM: trace events: update list of exit reasons KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously KVM: X86: Don't block vCPU if there is pending exception KVM: SVM: Add irqchip_split() checks before enabling AVIC KVM: Add struct kvm_vcpu pointer parameter to get_enable_apicv() KVM: SVM: Refactor AVIC vcpu initialization into avic_init_vcpu() KVM: x86: fix clang build ...
2017-09-15Merge tag 'powerpc-4.14-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fix from Michael Ellerman: "Just one fix, for the handling of alignment interrupts on dcbz instructions. Thanks to Paul Mackerras, Christian Zigotzky, Michal Sojka" * tag 'powerpc-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc: Fix handling of alignment interrupt on dcbz instruction
2017-09-15kvm,powerpc: Serialize wq active checks in ops->vcpu_kickDavidlohr Bueso
Particularly because kvmppc_fast_vcpu_kick_hv() is a callback, ensure that we properly serialize wq active checks in order to avoid potentially missing a wakeup due to racing with the waiter side. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-15powerpc: Fix handling of alignment interrupt on dcbz instructionPaul Mackerras
This fixes the emulation of the dcbz instruction in the alignment interrupt handler. The error was that we were comparing just the instruction type field of op.type rather than the whole thing, and therefore the comparison "type != CACHEOP + DCBZ" was always true. Fixes: 31bfdb036f12 ("powerpc: Use instruction emulation infrastructure to handle alignment faults") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Tested-by: Michal Sojka <sojkam1@fel.cvut.cz> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-14Merge branch 'kvm-ppc-fixes' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc Bug fixes for stable.
2017-09-14watchdog/hardlockup: Clean up hotplug locking messThomas Gleixner
All watchdog thread related functions are delegated to the smpboot thread infrastructure, which handles serialization against CPU hotplug correctly. The sysctl interface is completely decoupled from anything which requires CPU hotplug protection. No need to protect the sysctl writes against cpu hotplug anymore. Remove it and add the now required protection to the powerpc arch_nmi_watchdog implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Don Zickus <dzickus@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170912194148.418497420@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-14watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stageThomas Gleixner
Both the perf reconfiguration and the powerpc watchdog_nmi_reconfigure() need to be done in two steps. 1) Stop all NMIs 2) Read the new parameters and start NMIs Right now watchdog_nmi_reconfigure() is a combination of both. To allow a clean reconfiguration add a 'run' argument and split the functionality in powerpc. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Don Zickus <dzickus@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170912194147.862865570@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-14watchdog/core: Remove broken suspend/resume interfacesThomas Gleixner
This interface has several issues: - It's causing recursive locking of the hotplug lock. - It's complete overkill to teardown all threads and then recreate them The same can be achieved with the simple hardlockup_detector_perf_stop / restart() interfaces. The abuse from the busy looping poweroff() loop of PARISC has been solved as well. Remove the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Don Zickus <dzickus@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Link: http://lkml.kernel.org/r/20170912194146.487537732@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>