BMC/Intel-BMC/linux.git/arch/x86/kernel/cpuid.c, branch dev-5.2

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 142

2019-05-30T18:25:17+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation inc 675 mass ave cambridge ma 02139 usa either version 2 of the license or at your option any later version incorporated herein by reference extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 4 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Richard Fontana Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190524100844.465381181@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/cpuid: Allow cpuid_read() to schedule

2018-03-27T10:01:48+00:00

High latencies can be observed caused by a daemon periodically reading CPUID on all cpus. On KASAN enabled kernels ~10ms latencies can be observed. Even without KASAN, sending an IPI to a CPU, which is in a deep sleep state or in a long hard IRQ disabled section, waiting for the answer can consume hundreds of microseconds. cpuid_read() is invoked in preemptible context, so it can be converted to sleep instead of busy wait. Switching to smp_call_function_single_async() and a completion allows to reschedule and reduces CPU usage and latencies. Signed-off-by: Eric Dumazet Signed-off-by: Thomas Gleixner Acked-by: Ingo Molnar Cc: Hugh Dickins Cc: Borislav Petkov Cc: Eric Dumazet Link: https://lkml.kernel.org/r/20180323215818.127774-2-edumazet@google.com

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-13T03:25:04+00:00

Pull smp hotplug updates from Thomas Gleixner: "This is the final round of converting the notifier mess to the state machine. The removal of the notifiers and the related infrastructure will happen around rc1, as there are conversions outstanding in other trees. The whole exercise removed about 2000 lines of code in total and in course of the conversion several dozen bugs got fixed. The new mechanism allows to test almost every hotplug step standalone, so usage sites can exercise all transitions extensively. There is more room for improvement, like integrating all the pointlessly different architecture mechanisms of synchronizing, setting cpus online etc into the core code" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) tracing/rb: Init the CPU mask on allocation soc/fsl/qbman: Convert to hotplug state machine soc/fsl/qbman: Convert to hotplug state machine zram: Convert to hotplug state machine KVM/PPC/Book3S HV: Convert to hotplug state machine arm64/cpuinfo: Convert to hotplug state machine arm64/cpuinfo: Make hotplug notifier symmetric mm/compaction: Convert to hotplug state machine iommu/vt-d: Convert to hotplug state machine mm/zswap: Convert pool to hotplug state machine mm/zswap: Convert dst-mem to hotplug state machine mm/zsmalloc: Convert to hotplug state machine mm/vmstat: Convert to hotplug state machine mm/vmstat: Avoid on each online CPU loops mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead() tracing/rb: Convert to hotplug state machine oprofile/nmi timer: Convert to hotplug state machine net/iucv: Use explicit clean up labels in iucv_init() x86/pci/amd-bus: Convert to hotplug state machine x86/oprofile/nmi: Convert to hotplug state machine ...

x86/cpuid: Move the hotplug callbacks to online

2016-11-22T22:34:39+00:00

No point to have this file around before the cpu is online and no point to have it around until the cpu is dead. Get rid of the explicit state. Signed-off-by: Thomas Gleixner Cc: Sebastian Siewior

x86/cpuid: Convert to hotplug state machine

2016-11-22T22:34:39+00:00

Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Sebastian Andrzej Siewior Cc: rt@linuxtronix.de Link: http://lkml.kernel.org/r/20161117183541.8588-3-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner

x86/cpuid: Cleanup cpuid_regs definitions

2016-11-16T10:13:09+00:00

cpuid_regs is defined multiple times as structure and enum. Rename the enum and move all of it to processor.h so we don't end up with more instances. Rename the misnomed register enumeration from CR_* to the obvious CPUID_*. [ tglx: Rewrote changelog ] Signed-off-by: He Chen Reviewed-by: Borislav Petkov Cc: Luwei Kang Cc: kvm@vger.kernel.org Cc: Radim Krčmář Cc: Piotr Luc Cc: Paolo Bonzini Link: http://lkml.kernel.org/r/1478856336-9388-2-git-send-email-he.chen@linux.intel.com Signed-off-by: Thomas Gleixner

new helpers: no_seek_end_llseek{,_size}()

2015-12-23T15:41:31+00:00

Signed-off-by: Al Viro

x86: Drop bogus ref / refdata annotations

2015-07-20T16:57:20+00:00

The __ref / __refdata annotations used to be needed because of referencing functions / variables annotated __cpuinit / __cpuinitdata. But those annotations vanished during the development of v3.11. Therefore most of the __ref / __refdata annotations are not needed anymore. As they may hide legitimate sections mismatches, we better get rid of them. Signed-off-by: Mathias Krause Cc: Borislav Petkov Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1437409973-8927-1-git-send-email-minipli@googlemail.com Signed-off-by: Ingo Molnar

x86, cpuid: Use PTR_ERR_OR_ZERO

2014-10-17T20:40:51+00:00

Replace IS_ERR/PTR_ERR Signed-off-by: Fabian Frederick Link: http://lkml.kernel.org/r/1413576077-26969-1-git-send-email-fabf@skynet.be Signed-off-by: H. Peter Anvin

x86, cpuid: Fix CPU hotplug callback registration

2014-03-20T12:43:42+00:00

Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the cpuid code in x86 by using this latter form of callback registration. Cc: "H. Peter Anvin" Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki