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2019-08-19x86/irq: Check for VECTOR_UNUSED directlyHeiner Kallweit1-1/+1
It's simpler and more intuitive to directly check for VECTOR_UNUSED than checking whether the other error codes are not set. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/caeaca93-5ee1-cea1-8894-3aa0d5b19241@gmail.com
2019-08-19x86/irq: Move IS_ERR_OR_NULL() check into common do_IRQ() codeHeiner Kallweit1-2/+6
Both the 64bit and the 32bit handle_irq() implementation check the irq descriptor pointer with IS_ERR_OR_NULL() and return failure. That can be done simpler in the common do_IRQ() code. This reduces the 64bit handle_irq() function to a wrapper around generic_handle_irq_desc(). Invoke it directly from do_IRQ() to spare the extra function call. [ tglx: Got rid of the #ifdef and massaged changelog ] Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/2ec758c7-9aaa-73ab-f083-cc44c86aa741@gmail.com
2019-07-08Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updayes from Ingo Molnar: "Most of the commits add ACRN hypervisor guest support, plus two cleanups" * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/jailhouse: Mark jailhouse_x2apic_available() as __init x86/platform/geode: Drop <linux/gpio.h> includes x86/acrn: Use HYPERVISOR_CALLBACK_VECTOR for ACRN guest upcall vector x86: Add support for Linux guests on an ACRN hypervisor x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbol
2019-07-08Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x96 apic updates from Thomas Gleixner: "Updates for the x86 APIC interrupt handling and APIC timer: - Fix a long standing issue with spurious interrupts which was caused by the big vector management rework a few years ago. Robert Hodaszi provided finally enough debug data and an excellent initial failure analysis which allowed to understand the underlying issues. This contains a change to the core interrupt management code which is required to handle this correctly for the APIC/IO_APIC. The core changes are NOOPs for most architectures except ARM64. ARM64 is not impacted by the change as confirmed by Marc Zyngier. - Newer systems allow to disable the PIT clock for power saving causing panic in the timer interrupt delivery check of the IO/APIC when the HPET timer is not enabled either. While the clock could be turned on this would cause an endless whack a mole game to chase the proper register in each affected chipset. These systems provide the relevant frequencies for TSC, CPU and the local APIC timer via CPUID and/or MSRs, which allows to avoid the PIT/HPET based calibration. As the calibration code is the only usage of the legacy timers on modern systems and is skipped anyway when the frequencies are known already, there is no point in setting up the PIT and actually checking for the interrupt delivery via IO/APIC. To achieve this on a wide variety of platforms, the CPUID/MSR based frequency readout has been made more robust, which also allowed to remove quite some workarounds which turned out to be not longer required. Thanks to Daniel Drake for analysis, patches and verification" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Seperate unused system vectors from spurious entry again x86/irq: Handle spurious interrupt after shutdown gracefully x86/ioapic: Implement irq_get_irqchip_state() callback genirq: Add optional hardware synchronization for shutdown genirq: Fix misleading synchronize_irq() documentation genirq: Delay deactivation in free_irq() x86/timer: Skip PIT initialization on modern chipsets x86/apic: Use non-atomic operations when possible x86/apic: Make apic_bsp_setup() static x86/tsc: Set LAPIC timer period to crystal clock frequency x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period' x86/tsc: Use CPUID.0x16 to calculate missing crystal frequency
2019-07-03x86/irq: Handle spurious interrupt after shutdown gracefullyThomas Gleixner1-1/+1
Since the rework of the vector management, warnings about spurious interrupts have been reported. Robert provided some more information and did an initial analysis. The following situation leads to these warnings: CPU 0 CPU 1 IO_APIC interrupt is raised sent to CPU1 Unable to handle immediately (interrupts off, deep idle delay) mask() ... free() shutdown() synchronize_irq() clear_vector() do_IRQ() -> vector is clear Before the rework the vector entries of legacy interrupts were statically assigned and occupied precious vector space while most of them were unused. Due to that the above situation was handled silently because the vector was handled and the core handler of the assigned interrupt descriptor noticed that it is shut down and returned. While this has been usually observed with legacy interrupts, this situation is not limited to them. Any other interrupt source, e.g. MSI, can cause the same issue. After adding proper synchronization for level triggered interrupts, this can only happen for edge triggered interrupts where the IO-APIC obviously cannot provide information about interrupts in flight. While the spurious warning is actually harmless in this case it worries users and driver developers. Handle it gracefully by marking the vector entry as VECTOR_SHUTDOWN instead of VECTOR_UNUSED when the vector is freed up. If that above late handling happens the spurious detector will not complain and switch the entry to VECTOR_UNUSED. Any subsequent spurious interrupt on that line will trigger the spurious warning as before. Fixes: 464d12309e1b ("x86/vector: Switch IOAPIC to global reservation mode") Reported-by: Robert Hodaszi <Robert.Hodaszi@digi.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>- Tested-by: Robert Hodaszi <Robert.Hodaszi@digi.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/20190628111440.459647741@linutronix.de
2019-06-11x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbolZhao Yakui1-1/+1
Add a special Kconfig symbol X86_HV_CALLBACK_VECTOR so that the guests using the hypervisor interrupt callback counter can select and thus enable that counter. Select it when xen or hyperv support is enabled. No functional changes. Signed-off-by: Zhao Yakui <yakui.zhao@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: linux-hyperv@vger.kernel.org Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/1559108037-18813-2-git-send-email-yakui.zhao@intel.com
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-05x86: Don't include linux/irq.h from asm/hardirq.hNicolai Stange1-0/+1
The next patch in this series will have to make the definition of irq_cpustat_t available to entering_irq(). Inclusion of asm/hardirq.h into asm/apic.h would cause circular header dependencies like asm/smp.h asm/apic.h asm/hardirq.h linux/irq.h linux/topology.h linux/smp.h asm/smp.h or linux/gfp.h linux/mmzone.h asm/mmzone.h asm/mmzone_64.h asm/smp.h asm/apic.h asm/hardirq.h linux/irq.h linux/irqdesc.h linux/kobject.h linux/sysfs.h linux/kernfs.h linux/idr.h linux/gfp.h and others. This causes compilation errors because of the header guards becoming effective in the second inclusion: symbols/macros that had been defined before wouldn't be available to intermediate headers in the #include chain anymore. A possible workaround would be to move the definition of irq_cpustat_t into its own header and include that from both, asm/hardirq.h and asm/apic.h. However, this wouldn't solve the real problem, namely asm/harirq.h unnecessarily pulling in all the linux/irq.h cruft: nothing in asm/hardirq.h itself requires it. Also, note that there are some other archs, like e.g. arm64, which don't have that #include in their asm/hardirq.h. Remove the linux/irq.h #include from x86' asm/hardirq.h. Fix resulting compilation errors by adding appropriate #includes to *.c files as needed. Note that some of these *.c files could be cleaned up a bit wrt. to their set of #includes, but that should better be done from separate patches, if at all. Signed-off-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-03-06Drivers: hv: vmbus: Implement Direct Mode for stimer0Michael Kelley1-0/+7
The 2016 version of Hyper-V offers the option to operate the guest VM per-vcpu stimer's in Direct Mode, which means the timer interupts on its own vector rather than queueing a VMbus message. Direct Mode reduces timer processing overhead in both the hypervisor and the guest, and avoids having timer interrupts pollute the VMbus interrupt stream for the synthetic NIC and storage. This patch enables Direct Mode by default on stimer0 when running on a version of Hyper-V that supports it. In prep for coming support of Hyper-V on ARM64, the arch independent portion of the code contains calls to routines that will be populated on ARM64 but are not needed and do nothing on x86. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-30x86/irq: Count Hyper-V reenlightenment interruptsVitaly Kuznetsov1-0/+9
Hyper-V reenlightenment interrupts arrive when the VM is migrated, While they are not interesting in general it's important when L2 nested guests are running. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com> Link: https://lkml.kernel.org/r/20180124132337.30138-6-vkuznets@redhat.com
2017-12-18Merge branch 'WIP.x86-pti.entry-for-linus' of ↵Linus Torvalds1-12/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 syscall entry code changes for PTI from Ingo Molnar: "The main changes here are Andy Lutomirski's changes to switch the x86-64 entry code to use the 'per CPU entry trampoline stack'. This, besides helping fix KASLR leaks (the pending Page Table Isolation (PTI) work), also robustifies the x86 entry code" * 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) x86/cpufeatures: Make CPU bugs sticky x86/paravirt: Provide a way to check for hypervisors x86/paravirt: Dont patch flush_tlb_single x86/entry/64: Make cpu_entry_area.tss read-only x86/entry: Clean up the SYSENTER_stack code x86/entry/64: Remove the SYSENTER stack canary x86/entry/64: Move the IST stacks into struct cpu_entry_area x86/entry/64: Create a per-CPU SYSCALL entry trampoline x86/entry/64: Return to userspace from the trampoline stack x86/entry/64: Use a per-CPU trampoline stack for IDT entries x86/espfix/64: Stop assuming that pt_regs is on the entry stack x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 x86/entry: Remap the TSS into the CPU entry area x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct x86/dumpstack: Handle stack overflow on all stacks x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss x86/kasan/64: Teach KASAN about the cpu_entry_area x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area x86/entry/gdt: Put per-CPU GDT remaps in ascending order x86/dumpstack: Add get_stack_info() support for the SYSENTER stack ...
2017-12-17x86/irq: Remove an old outdated comment about context tracking racesAndy Lutomirski1-12/+0
That race has been fixed and code cleaned up for a while now. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150605.150551639@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-25x86/irq: Simplify hotplug vector accountingThomas Gleixner1-99/+0
Before a CPU is taken offline the number of active interrupt vectors on the outgoing CPU and the number of vectors which are available on the other online CPUs are counted and compared. If the active vectors are more than the available vectors on the other CPUs then the CPU hot-unplug operation is aborted. This again uses loop based search and is inaccurate. The bitmap matrix allocator has accurate accounting information and can tell exactly whether the vector space is sufficient or not. Emit a message when the number of globaly reserved (unallocated) vectors is larger than the number of available vectors after offlining a CPU because after that point request_irq() might fail. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Yu Chen <yu.c.chen@intel.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rui Zhang <rui.zhang@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Len Brown <lenb@kernel.org> Link: https://lkml.kernel.org/r/20170913213156.351193962@linutronix.de
2017-09-25x86/vector: Rename used_vectors to system_vectorsThomas Gleixner1-2/+2
used_vectors is a nisnomer as it only has the system vectors which are excluded from the regular vector allocation marked. It's not what the name suggests storage for the actually used vectors. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Yu Chen <yu.c.chen@intel.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rui Zhang <rui.zhang@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Len Brown <lenb@kernel.org> Link: https://lkml.kernel.org/r/20170913213154.150209009@linutronix.de
2017-08-29x86/ipi: Make platform IPI depend on APICThomas Gleixner1-5/+6
The platform IPI vector is only installed when the local APIC is enabled. All users of it depend on the local APIC anyway. Make the related code conditional on CONFIG_X86_LOCAL_APIC=y. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064957.615286163@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/irq: Get rid of duplicated trace_x86_platform_ipi() codeThomas Gleixner1-20/+5
Two NOP5s are really a good tradeoff vs. the unholy IDT switching mess, which duplicates code all over the place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170828064956.907209383@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/irq: Get rid of the 'first_system_vector' indirection bogosityThomas Gleixner1-1/+1
This variable is beyond pointless. Nothing allocates a vector via alloc_gate() below FIRST_SYSTEM_VECTOR. So nothing can change first_system_vector. If there is a need for a gate below FIRST_SYSTEM_VECTOR then it can be added to the vector defines and FIRST_SYSTEM_VECTOR can be adjusted accordingly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064956.357109735@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/irq: Remove vector_used_by_percpu_irq()Thomas Gleixner1-2/+0
Last user (lguest) is gone. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064956.201432430@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-26x86: irq: Define a global vector for nested posted interruptsWincy Van1-0/+19
We are using the same vector for nested/non-nested posted interrupts delivery, this may cause interrupts latency in L1 since we can't kick the L2 vcpu out of vmx-nonroot mode. This patch introduces a new vector which is only for nested posted interrupts to solve the problems above. Signed-off-by: Wincy Van <fanwenyi0529@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-22x86/irq: Use irq_migrate_all_off_this_cpu()Thomas Gleixner1-87/+2
The generic migration code supports all the required features already. Remove the x86 specific implementation and use the generic one. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.851311033@linutronix.de
2017-06-22x86/irq: Restructure fixup_irqs()Thomas Gleixner1-26/+20
Reorder fixup_irqs() so it matches the flow in the generic migration code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.774272454@linutronix.de
2017-06-22x86/irq: Cleanup pending irq move in fixup_irqs()Thomas Gleixner1-4/+21
If an CPU goes offline, the interrupts are migrated away, but a eventually pending interrupt move, which has not yet been made effective is kept pending even if the outgoing CPU is the sole target of the pending affinity mask. What's worse is, that the pending affinity mask is discarded even if it would contain a valid subset of the online CPUs. Use the newly introduced helper to: - Discard a pending move when the outgoing CPU is the only target in the pending mask. - Use the pending mask instead of the affinity mask to find a valid target for the CPU if the pending mask intersects with the online CPUs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235444.774068557@linutronix.de
2017-04-20x86/irq: Optimize free vector check in the CPU offline pathChen Yu1-2/+7
Before offlining a CPU its required to check whether there are enough free irq vectors available so interrupts can be migrated away from the CPU. This check is executed whether its required or not and neither stops searching when the number of required free vectors are reached. Bypass the free vector check if the current CPU has no irq to migrate and leave the for_each_online_cpu() loop when the free vector count reaches the number of required vectors. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Len Brown <lenb@kernel.orq> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Link: http://lkml.kernel.org/r/1492357410-510-1-git-send-email-yu.c.chen@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-05x86/irq, trace: Add __irq_entry annotation to x86's platform IRQ handlersDaniel Bristot de Oliveira1-2/+2
This patch adds the __irq_entry annotation to the default x86 platform IRQ handlers. ftrace's function_graph tracer uses the __irq_entry annotation to notify the entry and return of IRQ handlers. For example, before the patch: 354549.667252 | 3) d..1 | default_idle_call() { 354549.667252 | 3) d..1 | arch_cpu_idle() { 354549.667253 | 3) d..1 | default_idle() { 354549.696886 | 3) d..1 | smp_trace_reschedule_interrupt() { 354549.696886 | 3) d..1 | irq_enter() { 354549.696886 | 3) d..1 | rcu_irq_enter() { After the patch: 366416.254476 | 3) d..1 | arch_cpu_idle() { 366416.254476 | 3) d..1 | default_idle() { 366416.261566 | 3) d..1 ==========> | 366416.261566 | 3) d..1 | smp_trace_reschedule_interrupt() { 366416.261566 | 3) d..1 | irq_enter() { 366416.261566 | 3) d..1 | rcu_irq_enter() { KASAN also uses this annotation. The smp_apic_timer_interrupt() was already annotated. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Claudio Fontana <claudio.fontana@huawei.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicolai Stange <nicstange@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: linux-edac@vger.kernel.org Link: http://lkml.kernel.org/r/059fdf437c2f0c09b13c18c8fe4e69999d3ffe69.1483528431.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-09x86: Remove empty idle.h headerThomas Gleixner1-1/+0
One include less is always a good thing(tm). Good riddance. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/20161209182912.2726-6-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-11x86/irq: Do not substract irq_tlb_count from irq_call_countAaron Lu1-2/+1
Since commit: 52aec3308db8 ("x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR") the TLB remote shootdown is done through call function vector. That commit didn't take care of irq_tlb_count, which a later commit: fd0f5869724f ("x86: Distinguish TLB shootdown interrupts from other functions call interrupts") ... tried to fix. The fix assumes every increase of irq_tlb_count has a corresponding increase of irq_call_count. So the irq_call_count is always bigger than irq_tlb_count and we could substract irq_tlb_count from irq_call_count. Unfortunately this is not true for the smp_call_function_single() case. The IPI is only sent if the target CPU's call_single_queue is empty when adding a csd into it in generic_exec_single. That means if two threads are both adding flush tlb csds to the same CPU's call_single_queue, only one IPI is sent. In other words, the irq_call_count is incremented by 1 but irq_tlb_count is incremented by 2. Over time, irq_tlb_count will be bigger than irq_call_count and the substract will produce a very large irq_call_count value due to overflow. Considering that: 1) it's not worth to send more IPIs for the sake of accurate counting of irq_call_count in generic_exec_single(); 2) it's not easy to tell if the call function interrupt is for TLB shootdown in __smp_call_function_single_interrupt(). Not to exclude TLB shootdown from call function count seems to be the simplest fix and this patch just does that. This bug was found by LKP's cyclic performance regression tracking recently with the vm-scalability test suite. I have bisected to commit: 3dec0ba0be6a ("mm/rmap: share the i_mmap_rwsem") This commit didn't do anything wrong but revealed the irq_call_count problem. IIUC, the commit makes rwc->remap_one in rmap_walk_file concurrent with multiple threads. When remap_one is try_to_unmap_one(), then multiple threads could queue flush TLB to the same CPU but only one IPI will be sent. Since the commit was added in Linux v3.19, the counting problem only shows up from v3.19 onwards. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Cc: Alex Shi <alex.shi@linaro.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> Link: http://lkml.kernel.org/r/20160811074430.GA18163@aaronlu.sh.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-15x86/irq: Call irq_force_move_complete with irq descriptorThomas Gleixner1-1/+1
First of all there is no point in looking up the irq descriptor again, but we also need the descriptor for the final cleanup race fix in the next patch. Make that change seperate. No functional difference. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Borislav Petkov <bp@alien8.de> Tested-by: Joe Lawrence <joe.lawrence@stratus.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Jeremiah Mahler <jmmahler@gmail.com> Cc: andy.shevchenko@gmail.com Cc: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org #4.3+ Link: http://lkml.kernel.org/r/20151231160107.125211743@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-15x86/irq: Validate that irq descriptor is still activeThomas Gleixner1-0/+9
In fixup_irqs() we unconditionally dereference the irq chip of an irq descriptor. The descriptor might still be valid, but already cleaned up, i.e. the chip removed. Add a check for this condition. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Joe Lawrence <joe.lawrence@stratus.com> Cc: Jeremiah Mahler <jmmahler@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: andy.shevchenko@gmail.com Cc: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org #4.3+ Link: http://lkml.kernel.org/r/20151231160106.236423282@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-01Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds1-54/+48
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Thomas Gleixner: "This udpate contains: - rework the irq vector array to store a pointer to the irq descriptor instead of the irq number to avoid a lookup of the irq descriptor in the irq entry path - lguest interrupt handling cleanups - conversion of the local apic timer to the new clockevent callbacks - preparatory changes for the irq argument removal of interrupt flow handlers" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Do not dereference irq descriptor before checking it tools/lguest: Clean up include dir tools/lguest: Fix redefinition of struct virtio_pci_cfg_cap x86/irq: Store irq descriptor in vector array genirq: Provide irq_desc_has_action x86/irq: Get rid of an indentation level x86/irq: Rename VECTOR_UNDEFINED to VECTOR_UNUSED x86/irq: Replace numeric constant x86/irq: Protect smp_cleanup_move x86/lguest: Do not setup unused irq vectors x86/lguest: Clean up lguest_setup_irq x86/apic: Drop local_irq_save/restore in timer callbacks x86/apic: Migrate apic timer to new set_state interface x86/irq: Use access helper irq_data_get_affinity_mask() x86/irq: Use accessor irq_data_get_irq_handler_data() x86/irq: Use accessor irq_data_get_node()
2015-09-01Merge branch 'x86-irq-for-linus' of ↵Linus Torvalds1-4/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq fixlet from Ingo Molnar: "A single change that hides the 'HYP:' line in /proc/interrupts when it's unused" * 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Hide 'HYP:' line in /proc/interrupts when not on Xen/Hyper-V
2015-09-01Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-0/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm changes from Ingo Molnar: "The biggest changes in this cycle were: - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC) primitives. (Andy Lutomirski) - Add new, comprehensible entry and exit handlers written in C. (Andy Lutomirski) - vm86 mode cleanups and fixes. (Brian Gerst) - 32-bit compat code cleanups. (Brian Gerst) The amount of simplification in low level assembly code is already palpable: arch/x86/entry/entry_32.S | 130 +---- arch/x86/entry/entry_64.S | 197 ++----- but more simplifications are planned. There's also the usual laudry mix of low level changes - see the changelog for details" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits) x86/asm: Drop repeated macro of X86_EFLAGS_AC definition x86/asm/msr: Make wrmsrl() a function x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer x86/asm: Add MONITORX/MWAITX instruction support x86/traps: Weaken context tracking entry assertions x86/asm/tsc: Add rdtscll() merge helper selftests/x86: Add syscall_nt selftest selftests/x86: Disable sigreturn_64 x86/vdso: Emit a GNU hash x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks x86/entry/32: Migrate to C exit path x86/entry/32: Remove 32-bit syscall audit optimizations x86/vm86: Rename vm86->v86flags and v86mask x86/vm86: Rename vm86->vm86_info to user_vm86 x86/vm86: Clean up vm86.h includes x86/vm86: Move the vm86 IRQ definitions to vm86.h x86/vm86: Use the normal pt_regs area for vm86 x86/vm86: Eliminate 'struct kernel_vm86_struct' x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86' x86/vm86: Move vm86 fields out of 'thread_struct' ...
2015-08-06x86/irq: Store irq descriptor in vector arrayThomas Gleixner1-21/+16
We can spare the irq_desc lookup in the interrupt entry code if we store the descriptor pointer in the vector array instead the interrupt number. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/20150802203609.717724106@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-06x86/irq: Get rid of an indentation levelThomas Gleixner1-37/+35
Make the code simpler to read. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/20150802203609.555253675@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-06x86/irq: Rename VECTOR_UNDEFINED to VECTOR_UNUSEDThomas Gleixner1-4/+4
VECTOR_UNDEFINED is a misnomer. The vector is defined, but unused. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/20150802203609.477282494@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-06x86/irq: Replace numeric constantThomas Gleixner1-2/+2
Use the proper define instead of 0. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/20150802203609.385495420@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-06Merge branch 'linus' into x86/apicThomas Gleixner1-2/+18
Pull in upstream changes to avoid conflicts
2015-07-31Merge branch 'x86/urgent' into x86/asm, before applying dependent patchesIngo Molnar1-2/+18
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-13x86/irq: Use access helper irq_data_get_affinity_mask()Jiang Liu1-2/+3
This is a preparatory patch for moving irq_data struct members. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-08x86/irq: Hide 'HYP:' line in /proc/interrupts when not on Xen/Hyper-VVitaly Kuznetsov1-4/+7
Hypervisor callback interrupts are only accounted on Xen/Hyper-V. There is no point in having always-zero HYP: line on other hypervisors or bare metal. Print the line only if HYPERVISOR_CALLBACK_VECTOR was allocated. Reported-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Andrew Jones <drjones@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1436286373-11908-1-git-send-email-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-07x86/irq: Retrieve irq data after locking irq_descThomas Gleixner1-1/+6
irq_data is protected by irq_desc->lock, so retrieving the irq chip from irq_data outside the lock is racy vs. an concurrent update. Move it into the lock held region. While at it add a comment why the vector walk does not require vector_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: xiao jin <jin.xiao@intel.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Borislav Petkov <bp@suse.de> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Link: http://lkml.kernel.org/r/20150705171102.331320612@linutronix.de
2015-07-07x86/irq: Use proper locking in check_irq_vectors_for_cpu_disable()Thomas Gleixner1-1/+12
It's unsafe to examine fields in the irq descriptor w/o holding the descriptor lock. Add proper locking. While at it add a comment why the vector check can run lock less Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: xiao jin <jin.xiao@intel.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Borislav Petkov <bp@suse.de> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Link: http://lkml.kernel.org/r/20150705171102.236544164@linutronix.de
2015-07-07x86/irq, context_tracking: Document how IRQ context tracking works and add ↵Andy Lutomirski1-0/+15
an RCU assertion Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/e8bdc4ed0193fb2fd130f3d6b7b8023e2ec1ab62.1435952415.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07Merge branch 'x86/ras' into x86/core, to fix conflictsIngo Molnar1-0/+6
Conflicts: arch/x86/include/asm/irq_vectors.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/irq: Show statistics information for posted-interruptsFeng Wu1-0/+12
Show the statistics information for notification event and wakeup event for posted-interrupt in /proc/interrupts. [ tglx: Named the short identifiers PIN and PIW to match the long identifiers ] Signed-off-by: Feng Wu <feng.wu@intel.com> Cc: jiang.liu@linux.intel.com Link: http://lkml.kernel.org/r/1432026437-16560-5-git-send-email-feng.wu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19x86/irq: Define a global vector for VT-d Posted-InterruptsFeng Wu1-0/+26
Currently, we use a global vector as the Posted-Interrupts Notification Event for all the vCPUs in the system. We need to introduce another global vector for VT-d Posted-Interrtups, which will be used to wakeup the sleep vCPU when an external interrupt from a direct-assigned device happens for that vCPU. [ tglx: Removed a gazillion of extra newlines ] Signed-off-by: Feng Wu <feng.wu@intel.com> Cc: jiang.liu@linux.intel.com Link: http://lkml.kernel.org/r/1432026437-16560-4-git-send-email-feng.wu@intel.com Suggested-by: Yang Zhang <yang.z.zhang@intel.com> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-15x86: Use entering[_ack]_irq() instead of open coding itThomas Gleixner1-12/+4
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-10x86/irq: Merge irq_regs & irq_statBrian Gerst1-0/+6
Move irq_regs and irq_stat definitions to irq.c. Signed-off-by: Brian Gerst <brgerst@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431185813-15413-2-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07x86/mce/amd: Introduce deferred error interrupt handlerAravind Gopalakrishnan1-0/+6
Deferred errors indicate error conditions that were not corrected, but require no action from S/W (or action is optional).These errors provide info about a latent UC MCE that can occur when a poisoned data is consumed by the processor. Processors that report these errors can be configured to generate APIC interrupts to notify OS about the error. Provide an interrupt handler in this patch so that OS can catch these errors as and when they happen. Currently, we simply log the errors and exit the handler as S/W action is not mandated. Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1430913538-1415-5-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Borislav Petkov <bp@suse.de>
2015-03-02x86: Fix up obsolete __cpu_set() function usageRusty Russell1-2/+2
Thanks to spatch, plus manual removal of "&*". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425296150-4722-8-git-send-email-rusty@rustcorp.com.au Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-18x86/irq: Check for valid irq descriptor in check_irq_vectors_for_cpu_disable()Joerg Roedel1-0/+3
When an interrupt is migrated away from a cpu it will stay in its vector_irq array until smp_irq_move_cleanup_interrupt succeeded. The cfg->move_in_progress flag is cleared already when the IPI was sent. When the interrupt is destroyed after migration its 'struct irq_desc' is freed and the vector_irq arrays are cleaned up. But since cfg->move_in_progress is already 0 the references at cpus before the last migration will not be cleared. So this would leave a reference to an already destroyed irq alive. When the cpu is taken down at this point, the check_irq_vectors_for_cpu_disable() function finds a valid irq number in the vector_irq array, but gets NULL for its descriptor and dereferences it, causing a kernel panic. This has been observed on real systems at shutdown. Add a check to check_irq_vectors_for_cpu_disable() for a valid 'struct irq_desc' to prevent this issue. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Yinghai Lu <yinghai@kernel.org> Cc: alnovak@suse.com Cc: joro@8bytes.org Link: http://lkml.kernel.org/r/20150204132754.GA10078@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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