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2014-08-13Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/apic updates from Thomas Gleixner: "This is a major overhaul to the x86 apic subsystem consisting of the following parts: - Remove obsolete APIC driver abstractions (David Rientjes) - Use the irqdomain facilities to dynamically allocate IRQs for IOAPICs. This is a prerequisite to enable IOAPIC hotplug support, and it also frees up wasted vectors (Jiang Liu) - Misc fixlets. Despite the hickup in Ingos previous pull request - caused by the missing fixup for the suspend/resume issue reported by Borislav - I strongly recommend that this update finds its way into 3.17. Some history for you: This is preparatory work for physical IOAPIC hotplug. The first attempt to support this was done by Yinghai and I shot it down because it just added another layer of obscurity and complexity to the already existing mess without tackling the underlying shortcomings of the current implementation. After quite some on- and offlist discussions, I requested that the design of this functionality must use generic infrastructure, i.e. irq domains, which provide all the mechanisms to dynamically map linux interrupt numbers to physical interrupts. Jiang picked up the idea and did a great job of consolidating the existing interfaces to manage the x86 (IOAPIC) interrupt system by utilizing irq domains. The testing in tip, Linux-next and inside of Intel on various machines did not unearth any oddities until Borislav exposed it to one of his oddball machines. The issue was resolved quickly, but unfortunately the fix fell through the cracks and did not hit the tip tree before Ingo sent the pull request. Not entirely Ingos fault, I also assumed that the fix was already merged when Ingo asked me whether he could send it. Nevertheless this work has a proper design, has undergone several rounds of review and the final fallout after applying it to tip and integrating it into Linux-next has been more than moderate. It's the ground work not only for IOAPIC hotplug, it will also allow us to move the lowlevel vector allocation into the irqdomain hierarchy, which will benefit other architectures as well. Patches are posted already, but they are on hold for two weeks, see below. I really appreciate the competence and responsiveness Jiang has shown in course of this endavour. So I'm sure that any fallout of this will be addressed in a timely manner. FYI, I'm vanishing for 2 weeks into my annual kids summer camp kitchen duty^Wvacation, while you folks are drooling at KS/LinuxCon :) But HPA will have a look at the hopefully zero fallout until I'm back" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) x86, irq, PCI: Keep IRQ assignment for PCI devices during suspend/hibernation x86/apic/vsmp: Make is_vsmp_box() static x86, apic: Remove enable_apic_mode callback x86, apic: Remove setup_portio_remap callback x86, apic: Remove multi_timer_check callback x86, apic: Replace noop_check_apicid_used x86, apic: Remove check_apicid_present callback x86, apic: Remove mps_oem_check callback x86, apic: Remove smp_callin_clear_local_apic callback x86, apic: Replace trampoline physical addresses with defaults x86, apic: Remove x86_32_numa_cpu_node callback x86: intel-mid: Use the new io_apic interfaces x86, vsmp: Remove is_vsmp_box() from apic_is_clustered_box() x86, irq: Clean up irqdomain transition code x86, irq, devicetree: Release IOAPIC pin when PCI device is disabled x86, irq, SFI: Release IOAPIC pin when PCI device is disabled x86, irq, mpparse: Release IOAPIC pin when PCI device is disabled x86, irq, ACPI: Release IOAPIC pin when PCI device is disabled x86, irq: Introduce helper functions to release IOAPIC pin x86, irq: Simplify the way to handle ISA IRQ ...
2014-07-31x86, apic: Remove enable_apic_mode callbackDavid Rientjes
The enable_apic_mode() apic callback is never called, so remove it. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302352320.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Remove setup_portio_remap callbackDavid Rientjes
Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ, the setup_portio_remap() apic callback has been obsolete. Remove it. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302351480.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Remove multi_timer_check callbackDavid Rientjes
Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ, the multi_timer_check() apic callback has been obsolete. Remove it. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302351120.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Remove check_apicid_present callbackDavid Rientjes
The check_apicid_present() apic callback is never called, so remove it and functions that implement it. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302350160.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Remove mps_oem_check callbackDavid Rientjes
Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ, the mps_oem_check() apic callback has been obsolete. Remove it. This allows generic_mps_oem_check() to be removed as well. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302349390.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Remove smp_callin_clear_local_apic callbackDavid Rientjes
Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ, the smp_callin_clear_local_apic() apic callback has been obsolete. Remove it. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302349040.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Replace trampoline physical addresses with defaultsDavid Rientjes
The trampoline_phys_{high,low} members of struct apic are always initialized to DEFAULT_TRAMPOLINE_PHYS_HIGH and TRAMPOLINE_PHYS_LOW, respectively. Hardwire the constants and remove the unneeded members. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302348330.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-31x86, apic: Remove x86_32_numa_cpu_node callbackDavid Rientjes
Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ, the x86_32_numa_cpu_node() apic callback has been obsolete. Remove it. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302348060.17503@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-07-13x86, vsmp: Remove is_vsmp_box() from apic_is_clustered_box()Oren Twaig
When a vSMP Foundation box is detected, the function apic_cluster_num() counts the number of APIC clusters found. If more than one found, a multi board configuration is assumed, and TSC marked as unstable. This behavior is incorrect as vSMP Foundation may use processors from single node only, attached to memory of other nodes - and such node may have more than one APIC cluster (typically any recent intel box has more than single APIC_CLUSTERID(x)). To fix this, we simply remove the code which detects a vSMP Foundation box and affects apic_is_clusted_box() return value. This can be done because later the kernel checks by itself if the TSC is stable using the check_tsc_sync_[source|target]() functions and marks TSC as unstable if needed. Acked-by: Shai Fultheim <shai@scalemp.com> Signed-off-by: Oren Twaig <oren@scalemp.com> Link: http://lkml.kernel.org/r/1404036068-11674-1-git-send-email-oren@scalemp.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-06-21x86, mpparse: Simplify arch/x86/include/asm/mpspec.hJiang Liu
Simplify arch/x86/include/asm/mpspec.h by 1) Change max_physical_apicid to static as it's only used in apic.c. 2) Kill declaration of mpc_default_type, it's never defined. 3) Delete default_acpi_madt_oem_check(), it has already been declared in apic.h. 4) Make default_acpi_madt_oem_check() depends on CONFIG_X86_LOCAL_APIC instead of CONFIG_X86_64 to support i386. 5) Change mp_override_legacy_irq(), mp_config_acpi_legacy_irqs() and mp_register_gsi() as static because they are only used in acpi/boot.c. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Richard Weinberger <richard@nod.at> Cc: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1402302011-23642-4-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-06-18x86, cpufeature: Convert more "features" to bugsBorislav Petkov
X86_FEATURE_FXSAVE_LEAK, X86_FEATURE_11AP and X86_FEATURE_CLFLUSH_MONITOR are not really features but synthetic bits we use for applying different bug workarounds. Call them what they really are, and make sure they get the proper cross-CPU behavior (OR rather than AND). Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1403042783-23278-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-09x86/apic: Always define nox2apic and define it as initdataDavid Rientjes
The "nox2apic" variable can be defined as __initdata since it is only used for bootstrap. It can now unconditionally be defined since it will later be freed. At the same time, it is also better off as a bool. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354380.7839@chino.kir.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-09x86/apic: Remove unused function prototypesDavid Rientjes
Some function prototypes declared in asm/apic.h are never defined, so remove them. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354210.7839@chino.kir.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-09x86/apic: Switch wait_for_init_deassert() to a bool flagDavid Rientjes
Now that there is only a single wait_for_init_deassert() function, just convert the member of struct apic to a bool to determine whether we need to wait for init_deassert to become non-zero. There are no more callers of default_wait_for_init_deassert(), so fold it into the caller. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354010.7839@chino.kir.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-09x86/apic: Only use default_wait_for_init_deassert()David Rientjes
es7000_wait_for_init_deassert() is functionally equivalent to default_wait_for_init_deassert(), so remove the duplicate code and use only a single function. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042353030.7839@chino.kir.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-20x86/ioapic/kcrash: Prevent crash_kexec() from deadlocking on ioapic_lockYoshihiro YUNOMAE
Prevent crash_kexec() from deadlocking on ioapic_lock. When crash_kexec() is executed on a CPU, the CPU will take ioapic_lock in disable_IO_APIC(). So if the cpu gets an NMI while locking ioapic_lock, a deadlock will happen. In this patch, ioapic_lock is zapped/initialized before disable_IO_APIC(). You can reproduce this deadlock the following way: 1. Add mdelay(1000) after raw_spin_lock_irqsave() in native_ioapic_set_affinity()@arch/x86/kernel/apic/io_apic.c Although the deadlock can occur without this modification, it will increase the potential of the deadlock problem. 2. Build and install the kernel 3. Set up the OS which will run panic() and kexec when NMI is injected # echo "kernel.unknown_nmi_panic=1" >> /etc/sysctl.conf # vim /etc/default/grub add "nmi_watchdog=0 crashkernel=256M" in GRUB_CMDLINE_LINUX line # grub2-mkconfig 4. Reboot the OS 5. Run following command for each vcpu on the guest # while true; do echo <CPU num> > /proc/irq/<IO-APIC-edge or IO-APIC-fasteoi>/smp_affinitity; done; By running this command, cpus will get ioapic_lock for setting affinity. 6. Inject NMI (push a dump button or execute 'virsh inject-nmi <domain>' if you use VM). After injecting NMI, panic() is called in an nmi-handler context. Then, kexec will normally run in panic(), but the operation will be stopped by deadlock on ioapic_lock in crash_kexec()->machine_crash_shutdown()-> native_machine_crash_shutdown()->disable_IO_APIC()->clear_IO_APIC()-> clear_IO_APIC_pin()->ioapic_read_entry(). Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: yrl.pp-manager.tt@hitachi.com Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20130820070107.28245.83806.stgit@yunodevel Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20x86, trace: Introduce entering/exiting_irq()Seiji Aguchi
When implementing tracepoints in interrupt handers, if the tracepoints are simply added in the performance sensitive path of interrupt handers, it may cause potential performance problem due to the time penalty. To solve the problem, an idea is to prepare non-trace/trace irq handers and switch their IDTs at the enabling/disabling time. So, let's introduce entering_irq()/exiting_irq() for pre/post- processing of each irq handler. A way to use them is as follows. Non-trace irq handler: smp_irq_handler() { entering_irq(); /* pre-processing of this handler */ __smp_irq_handler(); /* * common logic between non-trace and trace handlers * in a vector. */ exiting_irq(); /* post-processing of this handler */ } Trace irq_handler: smp_trace_irq_handler() { entering_irq(); /* pre-processing of this handler */ trace_irq_entry(); /* tracepoint for irq entry */ __smp_irq_handler(); /* * common logic between non-trace and trace handlers * in a vector. */ trace_irq_exit(); /* tracepoint for irq exit */ exiting_irq(); /* post-processing of this handler */ } If tracepoints can place outside entering_irq()/exiting_irq() as follows, it looks cleaner. smp_trace_irq_handler() { trace_irq_entry(); smp_irq_handler(); trace_irq_exit(); } But it doesn't work. The problem is with irq_enter/exit() being called. They must be called before trace_irq_enter/exit(), because of the rcu_irq_enter() must be called before any tracepoints are used, as tracepoints use rcu to synchronize. As a possible alternative, we may be able to call irq_enter() first as follows if irq_enter() can nest. smp_trace_irq_hander() { irq_entry(); trace_irq_entry(); smp_irq_handler(); trace_irq_exit(); irq_exit(); } But it doesn't work, either. If irq_enter() is nested, it may have a time penalty because it has to check if it was already called or not. The time penalty is not desired in performance sensitive paths even if it is tiny. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/51C3238D.9040706@hds.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org>
2012-10-06sections: fix section conflicts in arch/x86Andi Kleen
Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-26Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/mm changes from Peter Anvin: "The big change here is the patchset by Alex Shi to use INVLPG to flush only the affected pages when we only need to flush a small page range. It also removes the special INVALIDATE_TLB_VECTOR interrupts (32 vectors!) and replace it with an ordinary IPI function call." Fix up trivial conflicts in arch/x86/include/asm/apic.h (added code next to changed line) * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tlb: Fix build warning and crash when building for !SMP x86/tlb: do flush_tlb_kernel_range by 'invlpg' x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR x86/tlb: enable tlb flush range support for x86 mm/mmu_gather: enable tlb flush range in generic mmu_gather x86/tlb: add tlb_flushall_shift knob into debugfs x86/tlb: add tlb_flushall_shift for specific CPU x86/tlb: fall back to flush all when meet a THP large page x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range x86/tlb_info: get last level TLB entry number of CPU x86: Add read_mostly declaration/definition to variables from smp.h x86: Define early read-mostly per-cpu macros
2012-07-24Merge tag 'kvm-3.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Avi Kivity: "Highlights include - full big real mode emulation on pre-Westmere Intel hosts (can be disabled with emulate_invalid_guest_state=0) - relatively small ppc and s390 updates - PCID/INVPCID support in guests - EOI avoidance; 3.6 guests should perform better on 3.6 hosts on interrupt intensive workloads) - Lockless write faults during live migration - EPT accessed/dirty bits support for new Intel processors" Fix up conflicts in: - Documentation/virtual/kvm/api.txt: Stupid subchapter numbering, added next to each other. - arch/powerpc/kvm/booke_interrupts.S: PPC asm changes clashing with the KVM fixes - arch/s390/include/asm/sigp.h, arch/s390/kvm/sigp.c: Duplicated commits through the kvm tree and the s390 tree, with subsequent edits in the KVM tree. * tag 'kvm-3.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (93 commits) KVM: fix race with level interrupts x86, hyper: fix build with !CONFIG_KVM_GUEST Revert "apic: fix kvm build on UP without IOAPIC" KVM guest: switch to apic_set_eoi_write, apic_write apic: add apic_set_eoi_write for PV use KVM: VMX: Implement PCID/INVPCID for guests with EPT KVM: Add x86_hyper_kvm to complete detect_hypervisor_platform check KVM: PPC: Critical interrupt emulation support KVM: PPC: e500mc: Fix tlbilx emulation for 64-bit guests KVM: PPC64: booke: Set interrupt computation mode for 64-bit host KVM: PPC: bookehv: Add ESR flag to Data Storage Interrupt KVM: PPC: bookehv64: Add support for std/ld emulation. booke: Added crit/mc exception handler for e500v2 booke/bookehv: Add host crit-watchdog exception support KVM: MMU: document mmu-lock and fast page fault KVM: MMU: fix kvm_mmu_pagetable_walk tracepoint KVM: MMU: trace fast page fault KVM: MMU: fast path of handling guest page fault KVM: MMU: introduce SPTE_MMU_WRITEABLE bit KVM: MMU: fold tlb flush judgement into mmu_spte_update ...
2012-07-16Revert "apic: fix kvm build on UP without IOAPIC"Michael S. Tsirkin
This reverts commit f9808b7fd422b965cea52e05ba470e0a473c53d3. After commit 'kvm: switch to apic_set_eoi_write, apic_write' the stubs are no longer needed as kvm does not look at apicdrivers anymore. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-16apic: add apic_set_eoi_write for PV useMichael S. Tsirkin
KVM PV EOI optimization overrides eoi_write apic op with its own version. Add an API for this to avoid meddling with core x86 apic driver data structures directly. For KVM use, we don't need any guarantees about when the switch to the new op will take place, so it could in theory use this API after SMP init, but it currently doesn't, and restricting callers to early init makes it clear that it's safe as it won't race with actual APIC driver use. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-06x86/apic/x2apic: Limit the vector reservation to the user specified maskSuresh Siddha
For the x2apic cluster mode, vector for an interrupt is currently reserved on all the cpu's that are part of the x2apic cluster. But the interrupts will be routed only to the cluster (derived from the first cpu in the mask) members specified in the mask. So there is no need to reserve the vector in the unused cluster members. Modify __assign_irq_vector() to reserve the vectors based on the user specified irq destination mask. If the new mask is a proper subset of the currently used mask, cleanup the vector allocation on the unused cpu members. Also, allow the apic driver to tune the vector domain based on the affinity mask (which in most cases is the user-specified mask). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Link: http://lkml.kernel.org/r/1340656709-11423-3-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-06x86/apic: Optimize cpu traversal in __assign_irq_vector() using domain ↵Suresh Siddha
membership Currently __assign_irq_vector() goes through each cpu in the specified mask until it finds a free vector in all the cpu's that are part of the same interrupt domain. We visit all the interrupt domain sibling cpus to reserve the free vector. So, when we fail to find a free vector in an interrupt domain, it is safe to continue our search with a cpu belonging to a new interrupt domain. No need to go through each cpu, if the domain containing that cpu is already visited. Use the irq_cfg's old_domain to track the visited domains and optimize the cpu traversal while finding a free vector in the given cpumask. NOTE: We can also optimize the search by using for_each_cpu() and skip the current cpu, if it is not the first cpu in the mask returned by the vector_allocation_domain(). But re-using the cfg->old_domain to track the visited domains will be slightly faster. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Link: http://lkml.kernel.org/r/1340656709-11423-2-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-03apic: fix kvm build on UP without IOAPICMichael S. Tsirkin
On UP i386, when APIC is disabled # CONFIG_X86_UP_APIC is not set # CONFIG_PCI_IOAPIC is not set code looking at apicdrivers never has any effect but it still gets compiled in. In particular, this causes build failures with kvm, but it generally bloats the kernel unnecessarily. Fix by defining both __apicdrivers and __apicdrivers_end to be NULL when CONFIG_X86_LOCAL_APIC is unset: I verified that as the result any loop scanning __apicdrivers gets optimized out by the compiler. Warning: a .config with apic disabled doesn't seem to boot for me (even without this patch). Still verifying why, meanwhile this patch is compile-tested only. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-06-14x86/apic: Eliminate cpu_mask_to_apicid() operationAlexander Gordeev
Since there are only two locations where cpu_mask_to_apicid() is called from, remove the operation and use only cpu_mask_to_apicid_and() instead. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Suggested-and-acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614074935.GE3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-14x86: Add read_mostly declaration/definition to variables from smp.hVlad Zolotarov
Add "read-mostly" qualifier to the following variables in smp.h: - cpu_sibling_map - cpu_core_map - cpu_llc_shared_map - cpu_llc_id - cpu_number - x86_cpu_to_apicid - x86_bios_cpu_apicid - x86_cpu_to_logical_apicid As long as all the variables above are only written during the initialization, this change is meant to prevent the false sharing. More specifically, on vSMP Foundation platform x86_cpu_to_apicid shared the same internode_cache_line with frequently written lapic_events. From the analysis of the first 33 per_cpu variables out of 219 (memories they describe, to be more specific) the 8 have read_mostly nature (tlb_vector_offset, cpu_loops_per_jiffy, xen_debug_irq, etc.) and 25 are frequently written (irq_stack_union, gdt_page, exception_stacks, idt_desc, etc.). Assuming that the spread of the rest of the per_cpu variables is similar, identifying the read mostly memories will make more sense in terms of long-term code maintenance comparing to identifying frequently written memories. Signed-off-by: Vlad Zolotarov <vlad@scalemp.com> Acked-by: Shai Fultheim <shai@scalemp.com> Cc: Shai Fultheim (Shai@ScaleMP.com) <Shai@scalemp.com> Cc: ido@wizery.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1719258.EYKzE4Zbq5@vlad Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08x86/apic: Make cpu_mask_to_apicid() operations check cpu_online_maskAlexander Gordeev
Currently cpu_mask_to_apicid() should not get a offline CPU with the cpumask. Otherwise some apic drivers might try to access non-existent per-cpu variables (i.e. x2apic). In that regard cpu_mask_to_apicid() and cpu_mask_to_apicid_and() operations are inconsistent. This fix makes the two operations do not rely on calling functions and always return the apicid for only online CPUs. As result, the meaning and implementations of cpu_mask_to_apicid() and cpu_mask_to_apicid_and() operations become straight. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131624.GG4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08x86/apic: Make cpu_mask_to_apicid() operations return error codeAlexander Gordeev
Current cpu_mask_to_apicid() and cpu_mask_to_apicid_and() implementations have few shortcomings: 1. A value returned by cpu_mask_to_apicid() is written to hardware registers unconditionally. Should BAD_APICID get ever returned it will be written to a hardware too. But the value of BAD_APICID is not universal across all hardware in all modes and might cause unexpected results, i.e. interrupts might get routed to CPUs that are not configured to receive it. 2. Because the value of BAD_APICID is not universal it is counter- intuitive to return it for a hardware where it does not make sense (i.e. x2apic). 3. cpu_mask_to_apicid_and() operation is thought as an complement to cpu_mask_to_apicid() that only applies a AND mask on top of a cpumask being passed. Yet, as consequence of 18374d8 commit the two operations are inconsistent in that of: cpu_mask_to_apicid() should not get a offline CPU with the cpumask cpu_mask_to_apicid_and() should not fail and return BAD_APICID These limitations are impossible to realize just from looking at the operations prototypes. Most of these shortcomings are resolved by returning a error code instead of BAD_APICID. As the result, faults are reported back early rather than possibilities to cause a unexpected behaviour exist (in case of [1]). The only exception is setup_timer_IRQ0_pin() routine. Although obviously controversial to this fix, its existing behaviour is preserved to not break the fragile check_timer() and would better addressed in a separate fix. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131559.GF4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector()Alexander Gordeev
In case of static vector allocation domains (i.e. flat) if all vector numbers are exhausted, an attempt to assign a new vector will lead to useless scans through all CPUs in the cpumask, even though it is known that each new pass would fail. Make this corner case less painful by letting report whether the vector allocation domain depends on passed arguments or not and stop scanning early. The same could have been achived by introducing a static flag to the apic operations. But let's allow vector_allocation_domain() have more intelligence here and decide dynamically, in case we would need it in the future. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131542.GE4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08x86/apic: Factor out default vector_allocation_domain() operationAlexander Gordeev
Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131449.GC4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06x86/apic: Factor out default cpu_mask_to_apicid() operationsAlexander Gordeev
Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120605112340.GA11454@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06x86/apic: Factor out default target_cpus() operationAlexander Gordeev
Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120605112324.GA11449@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-18x86/apic: Implement EIO micro-optimizationMichael S. Tsirkin
We know both register and value for eoi beforehand, so there's no need to check it and no need to do math to calculate the msr. Saves instructions/branches on each EOI when using x2apic. I looked at the objdump output to verify that the generated code looks right and actually is shorter. The real improvemements will be on the KVM guest side though, those come in a later patch. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: gleb@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/e019d1a125316f10d3e3a4b2f6bda41473f4fb72.1337184153.git.mst@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-18x86/apic: Add apic->eoi_write() callbackMichael S. Tsirkin
Add eoi_write callback so that kvm can override eoi accesses without touching the rest of the apic. As a side-effect, this will enable a micro-optimization for apics using msr. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: gleb@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/0df425d746c49ac2ecc405174df87752869629d2.1337184153.git.mst@redhat.com [ tidied it up a bit ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-18x86/apic: Use symbolic APIC_EOI_ACKMichael S. Tsirkin
Use the symbol instead of hard-coded numbers, now that the reason for the value is documented where the constant is defined we don't need to duplicate this explanation in code. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: gleb@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/ecbe4c79d69c172378e47e5a587ff5cd10293c9f.1337184153.git.mst@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-29Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 updates from Ingo Molnar. This touches some non-x86 files due to the sanitized INLINE_SPIN_UNLOCK config usage. Fixed up trivial conflicts due to just header include changes (removing headers due to cpu_idle() merge clashing with the <asm/system.h> split). * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic/amd: Be more verbose about LVT offset assignments x86, tls: Off by one limit check x86/ioapic: Add io_apic_ops driver layer to allow interception x86/olpc: Add debugfs interface for EC commands x86: Merge the x86_32 and x86_64 cpu_idle() functions x86/kconfig: Remove CONFIG_TR=y from the defconfigs x86: Stop recursive fault in print_context_stack after stack overflow x86/io_apic: Move and reenable irq only when CONFIG_GENERIC_PENDING_IRQ=y x86/apic: Add separate apic_id_valid() functions for selected apic drivers locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage x86/kconfig: Update defconfigs x86: Fix excessive MSR print out when show_msr is not specified
2012-03-28Disintegrate asm/system.h for X86David Howells
Disintegrate asm/system.h for X86. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> cc: x86@kernel.org
2012-03-23x86/apic: Add separate apic_id_valid() functions for selected apic driversSteffen Persvold
As suggested by Suresh Siddha and Yinghai Lu: For x2apic pre-enabled systems, apic driver is set already early through early_acpi_boot_init()/early_acpi_process_madt()/ acpi_parse_madt()/default_acpi_madt_oem_check() path so that apic_id_valid() checking will be sufficient during MADT and SRAT parsing. For non-x2apic pre-enabled systems, all apic ids should be less than 255. This allows us to substitute the checks in arch/x86/kernel/acpi/boot.c::acpi_parse_x2apic() and arch/x86/mm/srat.c::acpi_numa_x2apic_affinity_init() with apic->apic_id_valid(). In addition we can avoid feigning the x2apic cpu feature in the NumaChip apic code. The following apic drivers have separate apic_id_valid() functions which will accept x2apic type IDs : x2apic_phys x2apic_cluster x2apic_uv_x apic_numachip Signed-off-by: Steffen Persvold <sp@numascale.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Daniel J Blueman <daniel@numascale-asia.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Jack Steiner <steiner@sgi.com> Link: http://lkml.kernel.org/r/1331925935-13372-1-git-send-email-sp@numascale.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-14x86/platform: Move APIC ID validity check into platform APIC codeDaniel J Blueman
Move APIC ID validity check into platform APIC code, so it can be overridden when needed. For NumaChip systems, always trust MADT, as it's constructed with high APIC IDs. Behaviour verifies on standard x86 systems and on NumaChip systems with this, and compile-tested with allyesconfig. Signed-off-by: Daniel J Blueman <daniel@numascale-asia.com> Reviewed-by: Steffen Persvold <sp@numascale.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1331709454-27966-1-git-send-email-daniel@numascale-asia.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-23x86, x2apic: Allow "nox2apic" to disable x2apic mode setup by BIOSYinghai Lu
Currently "nox2apic" boot parameter was not enabling x2apic mode if the cpu, kernel are all capable of enabling x2apic mode and the OS handover happened in xapic mode. However If the bios enabled x2apic prior to OS handover, using "nox2apic" boot parameter had no effect. If the boot cpu's apicid is < 255, enable "nox2apic" boot parameter to disable the x2apic mode setup by the bios. This will enable the kernel to fallback to xapic mode and bringup only the cpu's which has apic-id < 255. -v2: fix patch error and two compiling warning make disable_x2apic to be __init Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/CAE9FiQUeB-3uxJAMiHsz=uPWoFv5Hg1pVepz7aU6YtqOxMC-=Q@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-12-23x86, x2apic: Fallback to xapic when BIOS doesn't setup interrupt-remappingYinghai Lu
On some of the recent Intel SNB platforms, by default bios is pre-enabling x2apic mode in the cpu with out setting up interrupt-remapping. This case was resulting in the kernel to panic as the cpu is already in x2apic mode but the OS was not able to enable interrupt-remapping (which is a pre-req for using x2apic capability). On these platforms all the apic-ids are < 255 and the kernel can fallback to xapic mode if the bios has not enabled interrupt-remapping (which is mostly the case if the bios has not exported interrupt-remapping tables to the OS). Reported-by: Berck E. Nash <flyboy@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20111222014632.600418637@sbsiddha-desk.sc.intel.com Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-12-18x86: Convert per-cpu counter icr_read_retry_count into a member of irq_statFernando Luis Vazquez Cao
LAPIC related statistics are grouped inside the per-cpu structure irq_stat, so there is no need for icr_read_retry_count to be a standalone per-cpu variable. This patch moves icr_read_retry_count to where it belongs. Suggested-y: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: Jörn Engel <joern@logfs.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-14x86: Add per-cpu stat counter for APIC ICR read triesFernando Luis Vázquez Cao
In the IPI delivery slow path (NMI delivery) we retry the ICR read to check for delivery completion a limited number of times. [ The reason for the limited retries is that some of the places where it is used (cpu boot, kdump, etc) IPI delivery might not succeed (due to a firmware bug or system crash, for example) and in such a case it is better to give up and resume execution of other code. ] This patch adds a new entry to /proc/interrupts, RTR, which tells user space the number of times we retried the ICR read in the IPI delivery slow path. This should give some insight into how well the APIC message delivery hardware is working - if the counts are way too large then we are hitting a (very-) slow path way too often. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: Jörn Engel <joern@logfs.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/n/tip-vzsp20lo2xdzh5f70g0eis2s@git.kernel.org [ extended the changelog ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-10x86/apic: Allow use of lapic timer early calibration resultJacob Pan
lapic timer calibration can be combined with tsc in platform specific calibration functions. if such calibration result is obtained early, we can skip the redundant calibration loops. Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-09-28apic, i386/bigsmp: Fix false warnings regarding logical APIC ID mismatchesJan Beulich
These warnings (generally one per CPU) are a result of initializing x86_cpu_to_logical_apicid while apic_default is still in use, but the check in setup_local_APIC() being done when apic_bigsmp was already used as an override in default_setup_apic_routing(): Overriding APIC driver with bigsmp Enabling APIC mode: Physflat. Using 5 I/O APICs ------------[ cut here ]------------ WARNING: at .../arch/x86/kernel/apic/apic.c:1239 ... CPU 1 irqstacks, hard=f1c9a000 soft=f1c9c000 Booting Node 0, Processors #1 smpboot cpu 1: start_ip = 9e000 Initializing CPU#1 ------------[ cut here ]------------ WARNING: at .../arch/x86/kernel/apic/apic.c:1239 setup_local_APIC+0x137/0x46b() Hardware name: ... CPU1 logical APIC ID: 2 != 8 ... Fix this (for the time being, i.e. until x86_32_early_logical_apicid() will get removed again, as Tejun says ought to be possible) by overriding the previously stored values at the point where the APIC driver gets overridden. v2: Move this and the pre-existing override logic into arch/x86/kernel/apic/bigsmp_32.c. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: <stable@kernel.org> (2.6.39 and onwards) Link: http://lkml.kernel.org/r/4E835D16020000780005844C@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-22x86, apic: Make apic drivers staticSuresh Siddha
Apic probe now looks at the apic drivers listed in the .apicdrivers section. Remove apic_probe[] and make each apic driver static. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: steiner@sgi.com Cc: gorcunov@openvz.org Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/20110521005526.341718626@sbsiddha-MOBL3.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-22x86, apic: Clean up bigsmp apic selection codeSuresh Siddha
Make generic_bigsmp_probe() return struct apic *. This will avoid exporting apic_bigsmp, which will be consistent with others. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: steiner@sgi.com Cc: gorcunov@openvz.org Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/20110521005526.252703851@sbsiddha-MOBL3.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>