#
8076fcde |
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11-Mar-2024 |
Pawan Gupta <pawan.kumar.gupta@linux.intel.com> |
x86/rfds: Mitigate Register File Data Sampling (RFDS) RFDS is a CPU vulnerability that may allow userspace to infer kernel stale data previously used in floating point registers, vector registers and integer registers. RFDS only affects certain Intel Atom processors. Intel released a microcode update that uses VERW instruction to clear the affected CPU buffers. Unlike MDS, none of the affected cores support SMT. Add RFDS bug infrastructure and enable the VERW based mitigation by default, that clears the affected buffers just before exiting to userspace. Also add sysfs reporting and cmdline parameter "reg_file_data_sampling" to control the mitigation. For details see: Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
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#
94483490 |
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13-Jan-2023 |
Ard Biesheuvel <ardb@kernel.org> |
Documentation: Drop or replace remaining mentions of IA64 Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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#
88a6f899 |
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14-Aug-2023 |
Eric DeVolder <eric.devolder@oracle.com> |
crash: memory and CPU hotplug sysfs attributes Introduce the crash_hotplug attribute for memory and CPUs for use by userspace. These attributes directly facilitate the udev rule for managing userspace re-loading of the crash kernel upon hot un/plug changes. For memory, expose the crash_hotplug attribute to the /sys/devices/system/memory directory. For example: # udevadm info --attribute-walk /sys/devices/system/memory/memory81 looking at device '/devices/system/memory/memory81': KERNEL=="memory81" SUBSYSTEM=="memory" DRIVER=="" ATTR{online}=="1" ATTR{phys_device}=="0" ATTR{phys_index}=="00000051" ATTR{removable}=="1" ATTR{state}=="online" ATTR{valid_zones}=="Movable" looking at parent device '/devices/system/memory': KERNELS=="memory" SUBSYSTEMS=="" DRIVERS=="" ATTRS{auto_online_blocks}=="offline" ATTRS{block_size_bytes}=="8000000" ATTRS{crash_hotplug}=="1" For CPUs, expose the crash_hotplug attribute to the /sys/devices/system/cpu directory. For example: # udevadm info --attribute-walk /sys/devices/system/cpu/cpu0 looking at device '/devices/system/cpu/cpu0': KERNEL=="cpu0" SUBSYSTEM=="cpu" DRIVER=="processor" ATTR{crash_notes}=="277c38600" ATTR{crash_notes_size}=="368" ATTR{online}=="1" looking at parent device '/devices/system/cpu': KERNELS=="cpu" SUBSYSTEMS=="" DRIVERS=="" ATTRS{crash_hotplug}=="1" ATTRS{isolated}=="" ATTRS{kernel_max}=="8191" ATTRS{nohz_full}==" (null)" ATTRS{offline}=="4-7" ATTRS{online}=="0-3" ATTRS{possible}=="0-7" ATTRS{present}=="0-3" With these sysfs attributes in place, it is possible to efficiently instruct the udev rule to skip crash kernel reloading for kernels configured with crash hotplug support. For example, the following is the proposed udev rule change for RHEL system 98-kexec.rules (as the first lines of the rule file): # The kernel updates the crash elfcorehdr for CPU and memory changes SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" When examined in the context of 98-kexec.rules, the above rules test if crash_hotplug is set, and if so, the userspace initiated unload-then-reload of the crash kernel is skipped. CPU and memory checks are separated in accordance with CONFIG_HOTPLUG_CPU and CONFIG_MEMORY_HOTPLUG kernel config options. If an architecture supports, for example, memory hotplug but not CPU hotplug, then the /sys/devices/system/memory/crash_hotplug attribute file is present, but the /sys/devices/system/cpu/crash_hotplug attribute file will NOT be present. Thus the udev rule skips userspace processing of memory hot un/plug events, but the udev rule will evaluate false for CPU events, thus allowing userspace to process CPU hot un/plug events (ie the unload-then-reload of the kdump capture kernel). Link: https://lkml.kernel.org/r/20230814214446.6659-5-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Akhil Raj <lf32.dev@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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#
7f48405c |
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05-Jul-2023 |
Michael Ellerman <mpe@ellerman.id.au> |
cpu/SMT: Allow enabling partial SMT states via sysfs Add support to the /sys/devices/system/cpu/smt/control interface for enabling a specified number of SMT threads per core, including partial SMT states where not all threads are brought online. The current interface accepts "on" and "off", to enable either 1 or all SMT threads per core. This commit allows writing an integer, between 1 and the number of SMT threads supported by the machine. Writing 1 is a synonym for "off", 2 or more enables SMT with the specified number of threads. When reading the file, if all threads are online "on" is returned, to avoid changing behaviour for existing users. If some other number of threads is online then the integer value is returned. Architectures like x86 only supporting 1 thread or all threads, should not define CONFIG_SMT_NUM_THREADS_DYNAMIC. Architecture supporting partial SMT states, like PowerPC, should define it. [ ldufour: Slightly reword the commit's description ] [ ldufour: Remove switch() in __store_smt_control() ] [ ldufour: Rix build issue in control_show() ] Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230705145143.40545-8-ldufour@linux.ibm.com
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8974eb58 |
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12-Jul-2023 |
Daniel Sneddon <daniel.sneddon@linux.intel.com> |
x86/speculation: Add Gather Data Sampling mitigation Gather Data Sampling (GDS) is a hardware vulnerability which allows unprivileged speculative access to data which was previously stored in vector registers. Intel processors that support AVX2 and AVX512 have gather instructions that fetch non-contiguous data elements from memory. On vulnerable hardware, when a gather instruction is transiently executed and encounters a fault, stale data from architectural or internal vector registers may get transiently stored to the destination vector register allowing an attacker to infer the stale data using typical side channel techniques like cache timing attacks. This mitigation is different from many earlier ones for two reasons. First, it is enabled by default and a bit must be set to *DISABLE* it. This is the opposite of normal mitigation polarity. This means GDS can be mitigated simply by updating microcode and leaving the new control bit alone. Second, GDS has a "lock" bit. This lock bit is there because the mitigation affects the hardware security features KeyLocker and SGX. It needs to be enabled and *STAY* enabled for these features to be mitigated against GDS. The mitigation is enabled in the microcode by default. Disable it by setting gather_data_sampling=off or by disabling all mitigations with mitigations=off. The mitigation status can be checked by reading: /sys/devices/system/cpu/vulnerabilities/gather_data_sampling Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
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e4624435 |
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12-Jun-2023 |
Jonathan Corbet <corbet@lwn.net> |
docs: arm64: Move arm64 documentation under Documentation/arch/ Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Move Documentation/arm64 into arch/ (along with the Chinese equvalent translations) and fix up documentation references. Cc: Will Deacon <will@kernel.org> Cc: Alex Shi <alexs@kernel.org> Cc: Hu Haowen <src.res@email.cn> Cc: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Yantengsi <siyanteng@loongson.cn> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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#
8a7f0e8a |
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31-Jul-2022 |
Randy Dunlap <rdunlap@infradead.org> |
Documentation/ABI: correct possessive "its" typos Correct all uses of "it's" that are meant to be possessive "its". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220801025207.29971-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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#
00da0cb3 |
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01-Aug-2022 |
Salvatore Bonaccorso <carnil@debian.org> |
Documentation/ABI: Mention retbleed vulnerability info file for sysfs While reporting for the AMD retbleed vulnerability was added in 6b80b59b3555 ("x86/bugs: Report AMD retbleed vulnerability") the new sysfs file was not mentioned so far in the ABI documentation for sysfs-devices-system-cpu. Fix that. Fixes: 6b80b59b3555 ("x86/bugs: Report AMD retbleed vulnerability") Signed-off-by: Salvatore Bonaccorso <carnil@debian.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220801091529.325327-1-carnil@debian.org
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#
1d248d23 |
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26-Jun-2022 |
Mauro Carvalho Chehab <mchehab@kernel.org> |
ABI: testing/sysfs-devices-system-cpu: remove duplicated core_id This was already defined at stable/sysfs-devices-system-cpu with the same description, as pointed by get_abi.pl: Warning: /sys/devices/system/cpu/cpuX/topology/core_id is defined 2 times: Documentation/ABI/stable/sysfs-devices-system-cpu:38 Documentation/ABI/testing/sysfs-devices-system-cpu:69 Remove the duplicated one. Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Link: https://lore.kernel.org/r/1e92337c1ef74f5eb9e1c1871e20b858b490d269.1656235926.git.mchehab@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d69d5649 |
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07-Jun-2022 |
Mark Brown <broonie@kernel.org> |
arm64/sme: Expose SMIDR through sysfs We currently expose MIDR and REVID to userspace through sysfs to enable it to make decisions based on the specific implementation. Since SME supports implementations where streaming mode is provided by a separate hardware unit called a SMCU it provides a similar ID register SMIDR. Expose it to userspace via sysfs when the system supports SME along with the other ID registers. Since we disable the SME priority mapping feature if it is supported by hardware we currently mask out the SMPS bit which reports that it is supported. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220607132857.1358361-1-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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#
8d50cdf8 |
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19-May-2022 |
Pawan Gupta <pawan.kumar.gupta@linux.intel.com> |
x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data Add the sysfs reporting file for Processor MMIO Stale Data vulnerability. It exposes the vulnerability and mitigation state similar to the existing files for the other hardware vulnerabilities. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de>
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9986c765 |
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09-Mar-2022 |
Evgenii Stepanov <eugenis@google.com> |
docs: sysfs-devices-system-cpu: document "asymm" value for mte_tcf_preferred It was added in commit 766121ba5de3 ("arm64/mte: Add userspace interface for enabling asymmetric mode"). Signed-off-by: Evgenii Stepanov <eugenis@google.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220309215943.87831-1-eugenis@google.com Signed-off-by: Will Deacon <will@kernel.org>
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ab28e944 |
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31-Jan-2022 |
Tony Luck <tony.luck@intel.com> |
topology/sysfs: Add PPIN in sysfs under cpu topology PPIN is the Protected Processor Identification Number. This is used to identify the socket as a Field Replaceable Unit (FRU). Existing code only displays this when reporting errors. But this makes it inconvenient for large clusters to use it for its intended purpose of inventory control. Add ppin to /sys/devices/system/cpu/cpu*/topology to make what is already available using RDMSR more easily accessible. Make the file read only for root in case there are still people concerned about making a unique system "serial number" available. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220131230111.2004669-6-tony.luck@intel.com
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02bf6074 |
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01-Dec-2021 |
Kohei Tarumizu <tarumizu.kohei@fujitsu.com> |
docs: document the sysfs ABI for "isolated" Add missing documentation of sysfs ABI for "isolated". It was added by commit 59f30abe94bf("show isolated cpus in sysfs"). However, there is no documentation for these interface. Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> Link: https://lore.kernel.org/r/20211201115957.254224-3-tarumizu.kohei@fujitsu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
3722e7c3 |
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01-Dec-2021 |
Kohei Tarumizu <tarumizu.kohei@fujitsu.com> |
docs: document the sysfs ABI for "nohz_full" Add missing documentation of sysfs ABI for "nohz_full". It was added by commit 6570a9a1ce3a("show nohz_full cpus in sysfs"). However, there is no documentation for these interface. Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> Link: https://lore.kernel.org/r/20211201115957.254224-2-tarumizu.kohei@fujitsu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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abcb948d |
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30-Sep-2021 |
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
ABI: sysfs-devices-system-cpu: use cpuX instead of cpu# Some What entries here use cpu# as a wildcard, while others use, instead, cpuX. As scripts/get_abi.pl doesn't consider "#" as a wildcard, replace: cpu# -> cpuX inside the file. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/60b1a79189d1a9d9f1c9c9c299770e69b18972fd.1632994837.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
26d6ba2f |
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16-Sep-2021 |
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
ABI: sysfs-devices-system-cpu: use wildcards on What definitions An "N" upper letter is not a wildcard, nor can easily be identified by script, specially since the USB sysfs define things like. bNumInterfaces. Use, instead, <N>, in order to let script/get_abi.pl to convert it into a Regex. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/d18385a391b6797373a5d1382ea024857fb29987.1631782432.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7af33504 |
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29-Jul-2021 |
Will Deacon <will@kernel.org> |
arm64: Advertise CPUs capable of running 32-bit applications in sysfs Since 32-bit applications will be killed if they are caught trying to execute on a 64-bit-only CPU in a mismatched system, advertise the set of 32-bit capable CPUs to userspace in sysfs. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-14-will@kernel.org
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80c7c36f |
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27-Jul-2021 |
Peter Collingbourne <pcc@google.com> |
Documentation: document the preferred tag checking mode feature Document the functionality added in the previous patches. Link: https://linux-review.googlesource.com/id/I48217cc3e8b8da33abc08cbaddc11cf4360a1b86 Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210727205300.2554659-6-pcc@google.com Acked-by: Will Deacon <will@kernel.org> [catalin.marinas@arm.com: clarify that the change happens on task scheduling] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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3e42d1de |
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13-May-2021 |
Carlos Bilbao <bilbao@vt.edu> |
docs: typo fixes in Documentation/ABI/ Fix the following typos in the Documentation/ABI/ directory: - In file obsolete/sysfs-cpuidle, change "obselete" for "obsolete". - In file removed/sysfs-kernel-uids, change "propotional" for "proportional". - In directory stable/, fix the following words: "associtated" for "associated", "hexidecimal" for "hexadecimal", "vlue" for "value", "csed" for "caused" and "wrtie" for "write". This updates a total of five files. - In directory testing/, fix the following words: "subystem" for "subsystem", "isochrnous" for "isochronous", "Desctiptors" for "Descriptors", "picutre" for "picture", "capture" for "capture", "occured" for "ocurred", "connnected" for "connected","agressively" for "aggressively","manufacturee" for "manufacturer" and "transaction" for "transaction", "malformatted" for "incorrectly formated" ,"internel" for "internal", "writtento" for "written to", "specificed" for "specified", "beyound" for "beyond", "Symetric" for "Symmetric". This updates a total of eleven files. Signed-off-by: Carlos Bilbao <bilbao@vt.edu> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5710038.lOV4Wx5bFT@iron-maiden Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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2fa4928a |
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28-Apr-2021 |
Anatoly Pugachev <matorola@gmail.com> |
docs: correct URL to bios and kernel developer's guide correct URL to bios and kernel developer's guide on amd.com site Signed-off-by: Anatoly Pugachev <matorola@gmail.com> Link: https://lore.kernel.org/r/20210428104851.GA10572@u164.east.ru [jc: fixed resulting sphinx warning] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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cfdc589f |
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13-Dec-2020 |
Ionela Voinescu <ionela.voinescu@arm.com> |
cppc_cpufreq: expose information on frequency domains Use the existing sysfs attribute "freqdomain_cpus" to expose information to userspace about CPUs in the same frequency domain. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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54a19b4d |
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30-Oct-2020 |
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
docs: ABI: cleanup several ABI documents There are some ABI documents that, while they don't generate any warnings, they have issues when parsed by get_abi.pl script on its output result. Address them, in order to provide a clean output. Reviewed-by: Tom Rix <trix@redhat.com> # for fpga-manager Reviewed-By: Kajol Jain<kjain@linux.ibm.com> # for sysfs-bus-event_source-devices-hv_gpci and sysfs-bus-event_source-devices-hv_24x7 Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO Acked-by: Oded Gabbay <oded.gabbay@gmail.com> # for Habanalabs Acked-by: Vaibhav Jain <vaibhav@linux.ibm.com> # for sysfs-bus-papr-pmem Acked-by: Cezary Rojewski <cezary.rojewski@intel.com> # for catpt Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Ilya Dryomov <idryomov@gmail.com> # for rbd Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5bc78e5b68ed1e9e39135173857cb2e753be868f.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
34433332 |
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30-Oct-2020 |
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
docs: ABI: testing: make the files compatible with ReST output Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7395683a |
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19-May-2020 |
Hanjun Guo <guohanjun@huawei.com> |
Documentation: cpuidle: update the document Update the document after the remove of cpuidle_sysfs_switch. Signed-off-by: Hanjun Guo <guohanjun@huawei.com> Reviewed-by: Doug Smythies <dsmythies@telus.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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bde752c3 |
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07-Apr-2020 |
Gautham R. Shenoy <ego@linux.vnet.ibm.com> |
Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr Add documentation for the following sysfs interfaces: /sys/devices/system/cpu/cpuX/purr /sys/devices/system/cpu/cpuX/spurr /sys/devices/system/cpu/cpuX/idle_purr /sys/devices/system/cpu/cpuX/idle_spurr Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1586249263-14048-6-git-send-email-ego@linux.vnet.ibm.com
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#
7e5b3c26 |
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16-Apr-2020 |
Mark Gross <mgross@linux.intel.com> |
x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigation SRBDS is an MDS-like speculative side channel that can leak bits from the random number generator (RNG) across cores and threads. New microcode serializes the processor access during the execution of RDRAND and RDSEED. This ensures that the shared buffer is overwritten before it is released for reuse. While it is present on all affected CPU models, the microcode mitigation is not needed on models that enumerate ARCH_CAPABILITIES[MDS_NO] in the cases where TSX is not supported or has been disabled with TSX_CTRL. The mitigation is activated by default on affected processors and it increases latency for RDRAND and RDSEED instructions. Among other effects this will reduce throughput from /dev/urandom. * Enable administrator to configure the mitigation off when desired using either mitigations=off or srbds=off. * Export vulnerability status via sysfs * Rename file-scoped macros to apply for non-whitelist table initializations. [ bp: Massage, - s/VULNBL_INTEL_STEPPING/VULNBL_INTEL_STEPPINGS/g, - do not read arch cap MSR a second time in tsx_fused_off() - just pass it in, - flip check in cpu_set_bug_bits() to save an indentation level, - reflow comments. jpoimboe: s/Mitigated/Mitigation/ in user-visible strings tglx: Dropped the fused off magic for now ] Signed-off-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
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75a80267 |
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13-Dec-2019 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
cpuidle: Allow idle states to be disabled by default In certain situations it may be useful to prevent some idle states from being used by default while allowing user space to enable them later on. For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to mark idle states that should be disabled by default, make the core set CPUIDLE_STATE_DISABLED_BY_USER for those states at the initialization time and add a new state attribute in sysfs, "default_status", to inform user space of the initial status of the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it, "enabled" otherwise). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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db4d30fb |
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03-Nov-2019 |
Vineela Tummalapalli <vineela.tummalapalli@intel.com> |
x86/bugs: Add ITLB_MULTIHIT bug infrastructure Some processors may incur a machine check error possibly resulting in an unrecoverable CPU lockup when an instruction fetch encounters a TLB multi-hit in the instruction TLB. This can occur when the page size is changed along with either the physical address or cache type. The relevant erratum can be found here: https://bugzilla.kernel.org/show_bug.cgi?id=205195 There are other processors affected for which the erratum does not fully disclose the impact. This issue affects both bare-metal x86 page tables and EPT. It can be mitigated by either eliminating the use of large pages or by using careful TLB invalidations when changing the page size in the page tables. Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which are mitigated against this issue. Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com> Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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a7a248c5 |
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22-Oct-2019 |
Pawan Gupta <pawan.kumar.gupta@linux.intel.com> |
x86/speculation/taa: Add documentation for TSX Async Abort Add the documenation for TSX Async Abort. Include the description of the issue, how to check the mitigation state, control the mitigation, guidance for system administrators. [ bp: Add proper SPDX tags, touch ups by Josh and me. ] Co-developed-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mark Gross <mgross@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
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734560ac |
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19-Aug-2019 |
Ryan Grimm <grimm@linux.vnet.ibm.com> |
powerpc/pseries/svm: Export guest SVM status to user space via sysfs User space might want to know it's running in a secure VM. It can't do a mfmsr because mfmsr is a privileged instruction. The solution here is to create a cpu attribute: /sys/devices/system/cpu/svm which will read 0 or 1 based on the S bit of the current CPU. Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820021326.6884-12-bauerman@linux.ibm.com
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4f4cfa6c |
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27-Jun-2019 |
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
docs: admin-guide: add a series of orphaned documents There are lots of documents that belong to the admin-guide but are on random places (most under Documentation root dir). Move them to the admin guide. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
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#
203dffac |
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19-Jun-2019 |
Fenghua Yu <fenghua.yu@intel.com> |
Documentation/ABI: Document umwait control sysfs interfaces Since two new sysfs interface files are created for umwait control, add an ABI document entry for the files: /sys/devices/system/cpu/umwait_control/enable_c02 /sys/devices/system/cpu/umwait_control/max_time [ tglx: Made the write value instructions readable ] Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ashok Raj <ashok.raj@intel.com> Cc: "Borislav Petkov" <bp@alien8.de> Cc: "H Peter Anvin" <hpa@zytor.com> Cc: "Andy Lutomirski" <luto@kernel.org> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Tony Luck" <tony.luck@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Link: https://lkml.kernel.org/r/1560994438-235698-6-git-send-email-fenghua.yu@intel.com
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671c3095 |
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07-Jun-2019 |
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
ABI: sysfs-devices-system-cpu: point to the right docs The cpuidle doc was split on two, one at the admin guide and another one at the driver API guide. Instead of pointing to a non-existent file, point to both (admin guide being the first one). Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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b9c273ba |
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21-Mar-2019 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface The Performance and Energy Bias Hint (EPB) is expected to be set by user space through the generic MSR interface, but that interface is not particularly nice and there are security concerns regarding it, so it is not always available. For this reason, add a sysfs interface for reading and updating the EPB, in the form of a new attribute, energy_perf_bias, located under /sys/devices/system/cpu/cpu#/power/ for online CPUs that support the EPB feature. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Borislav Petkov <bp@suse.de>
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de7b77e5 |
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27-Mar-2019 |
Josh Poimboeuf <jpoimboe@redhat.com> |
cpu/hotplug: Create SMT sysfs interface for all arches Make the /sys/devices/system/cpu/smt/* files available on all arches, so user space has a consistent way to detect whether SMT is enabled. The 'control' file now shows 'notimplemented' for architectures which don't yet have CONFIG_HOTPLUG_SMT. [ tglx: Make notimplemented a real state ] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <longman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Link: https://lkml.kernel.org/r/469c2b98055f2c41e75748e06447d592a64080c9.1553635520.git.jpoimboe@redhat.com
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5999bbe7 |
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18-Feb-2019 |
Thomas Gleixner <tglx@linutronix.de> |
Documentation: Add MDS vulnerability documentation Add the initial MDS vulnerability documentation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jon Masters <jcm@redhat.com>
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65fd4cb6 |
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19-Feb-2019 |
Thomas Gleixner <tglx@linutronix.de> |
Documentation: Move L1TF to separate directory Move L!TF to a separate directory so the MDS stuff can be added at the side. Otherwise the all hardware vulnerabilites have their own top level entry. Should have done that right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jon Masters <jcm@redhat.com>
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8a4b06d3 |
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18-Feb-2019 |
Thomas Gleixner <tglx@linutronix.de> |
x86/speculation/mds: Add sysfs reporting for MDS Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
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04dab58a |
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09-Dec-2018 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
cpuidle: Add 'above' and 'below' idle state metrics Add two new metrics for CPU idle states, "above" and "below", to count the number of times the given state had been asked for (or entered from the kernel's perspective), but the observed idle duration turned out to be too short or too long for it (respectively). These metrics help to estimate the quality of the CPU idle governor in use. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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#
d90a7a0e |
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13-Jul-2018 |
Jiri Kosina <jkosina@suse.cz> |
x86/bugs, kvm: Introduce boot-time control of L1TF mitigations Introduce the 'l1tf=' kernel command line option to allow for boot-time switching of mitigation that is used on processors affected by L1TF. The possible values are: full Provides all available mitigations for the L1TF vulnerability. Disables SMT and enables all mitigations in the hypervisors. SMT control via /sys/devices/system/cpu/smt/control is still possible after boot. Hypervisors will issue a warning when the first VM is started in a potentially insecure configuration, i.e. SMT enabled or L1D flush disabled. full,force Same as 'full', but disables SMT control. Implies the 'nosmt=force' command line option. sysfs control of SMT and the hypervisor flush control is disabled. flush Leaves SMT enabled and enables the conditional hypervisor mitigation. Hypervisors will issue a warning when the first VM is started in a potentially insecure configuration, i.e. SMT enabled or L1D flush disabled. flush,nosmt Disables SMT and enables the conditional hypervisor mitigation. SMT control via /sys/devices/system/cpu/smt/control is still possible after boot. If SMT is reenabled or flushing disabled at runtime hypervisors will issue a warning. flush,nowarn Same as 'flush', but hypervisors will not warn when a VM is started in a potentially insecure configuration. off Disables hypervisor mitigations and doesn't emit any warnings. Default is 'flush'. Let KVM adhere to these semantics, which means: - 'lt1f=full,force' : Performe L1D flushes. No runtime control possible. - 'l1tf=full' - 'l1tf-flush' - 'l1tf=flush,nosmt' : Perform L1D flushes and warn on VM start if SMT has been runtime enabled or L1D flushing has been run-time enabled - 'l1tf=flush,nowarn' : Perform L1D flushes and no warnings are emitted. - 'l1tf=off' : L1D flushes are not performed and no warnings are emitted. KVM can always override the L1D flushing behavior using its 'vmentry_l1d_flush' module parameter except when lt1f=full,force is set. This makes KVM's private 'nosmt' option redundant, and as it is a bit non-systematic anyway (this is something to control globally, not on hypervisor level), remove that option. Add the missing Documentation entry for the l1tf vulnerability sysfs file while at it. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20180713142323.202758176@linutronix.de
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05736e4a |
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29-May-2018 |
Thomas Gleixner <tglx@linutronix.de> |
cpu/hotplug: Provide knobs to control SMT Provide a command line and a sysfs knob to control SMT. The command line options are: 'nosmt': Enumerate secondary threads, but do not online them 'nosmt=force': Ignore secondary threads completely during enumeration via MP table and ACPI/MADT. The sysfs control file has the following states (read/write): 'on': SMT is enabled. Secondary threads can be freely onlined 'off': SMT is disabled. Secondary threads, even if enumerated cannot be onlined 'forceoff': SMT is permanentely disabled. Writes to the control file are rejected. 'notsupported': SMT is not supported by the CPU The command line option 'nosmt' sets the sysfs control to 'off'. This can be changed to 'on' to reenable SMT during runtime. The command line option 'nosmt=force' sets the sysfs control to 'forceoff'. This cannot be changed during runtime. When SMT is 'on' and the control file is changed to 'off' then all online secondary threads are offlined and attempts to online a secondary thread later on are rejected. When SMT is 'off' and the control file is changed to 'on' then secondary threads can be onlined again. The 'off' -> 'on' transition does not automatically online the secondary threads. When the control file is set to 'forceoff', the behaviour is the same as setting it to 'off', but the operation is irreversible and later writes to the control file are rejected. When the control status is 'notsupported' then writes to the control file are rejected. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org>
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6ec71b20 |
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13-Jun-2018 |
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
ABI: sysfs-devices-system-cpu: remove a broken reference This file doesn't exist anymore: Documentation/cpu-freq/user-guide.txt As the ABI already points to Documentation/cpu-freq, just remove the broken link and the associated text. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Jonathan Corbet <corbet@lwn.net>
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c456442c |
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25-Apr-2018 |
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> |
x86/bugs: Expose /sys/../spec_store_bypass Add the sysfs file for the new vulerability. It does not do much except show the words 'Vulnerable' for recent x86 cores. Intel cores prior to family 6 are known not to be vulnerable, and so are some Atoms and some Xeon Phi. It assumes that older Cyrix, Centaur, etc. cores are immune. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
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64bdff69 |
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13-Mar-2018 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM: cpuidle/suspend: Add s2idle usage and time state attributes Add a new attribute group called "s2idle" under the sysfs directory of each cpuidle state that supports the ->enter_s2idle callback and put two new attributes, "usage" and "time", into that group to represent the number of times the given state was requested for suspend-to-idle and the total time spent in suspend-to-idle after requesting that state, respectively. That will allow diagnostic information related to suspend-to-idle to be collected without enabling advanced debug features and analyzing dmesg output. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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b6d8ef86 |
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07-Feb-2018 |
Aishwarya Pant <aishpant@gmail.com> |
Documentation/ABI: update cpuidle sysfs documentation Update cpuidle documentation using git logs and existing documentation in Documentation/cpuidle/sysfs.txt. This might be useful for scripting and tracking changes in the ABI. Signed-off-by: Aishwarya Pant <aishpant@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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9ecccfaa |
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09-Jan-2018 |
David Woodhouse <dwmw@amazon.co.uk> |
sysfs/cpu: Fix typos in vulnerability documentation Fixes: 87590ce6e ("sysfs/cpu: Add vulnerability folder") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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87590ce6 |
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07-Jan-2018 |
Thomas Gleixner <tglx@linutronix.de> |
sysfs/cpu: Add vulnerability folder As the meltdown/spectre problem affects several CPU architectures, it makes sense to have common way to express whether a system is affected by a particular vulnerability or not. If affected the way to express the mitigation should be common as well. Create /sys/devices/system/cpu/vulnerabilities folder and files for meltdown, spectre_v1 and spectre_v2. Allow architectures to override the show function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de
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3ba9b1b8 |
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09-Oct-2017 |
Tom Saeger <tom.saeger@oracle.com> |
Documentation: fix admin-guide doc refs Make admin-guide document refs valid. Signed-off-by: Tom Saeger <tom.saeger@oracle.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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a2b60670 |
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27-Mar-2017 |
Juri Lelli <juri.lelli@arm.com> |
Documentation/ABI: add information about cpu_capacity /sys/devices/system/cpu/cpu#/cpu_capacity describe information about CPUs heterogeneity (ref. to Documentation/devicetree/bindings/arm/ cpu-capacity.txt). Add such description. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1d78dc59 |
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22-Oct-2016 |
Tony Luck <tony.luck@intel.com> |
Documentation, ABI: Document the new sysfs files for cpu cache ids Add an ABI document entry for /sys/devices/system/cpu/cpu*/cache/index*/id. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Cc: "David Carrillo-Cisneros" <davidcc@google.com> Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Stephane Eranian" <eranian@google.com> Cc: "Dave Hansen" <dave.hansen@intel.com> Cc: "Shaohua Li" <shli@fb.com> Cc: "Nilay Vaish" <nilayvaish@gmail.com> Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com> Cc: "Ingo Molnar" <mingo@elte.hu> Cc: "Borislav Petkov" <bp@suse.de> Cc: "H. Peter Anvin" <h.peter.anvin@intel.com> Link: http://lkml.kernel.org/r/1477142405-32078-2-git-send-email-fenghua.yu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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f8d9f924 |
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08-Jul-2016 |
Steve Capper <steve.capper@linaro.org> |
arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs It can be useful for JIT software to be aware of MIDR_EL1 and REVIDR_EL1 to ascertain the presence of any core errata that could affect code generation. This patch exposes these registers through sysfs: /sys/devices/system/cpu/cpu$ID/regs/identification/midr_el1 /sys/devices/system/cpu/cpu$ID/regs/identification/revidr_el1 where $ID is the cpu number. For big.LITTLE systems, one can have a mixture of cores (e.g. Cortex A53 and Cortex A57), thus all CPUs need to be enumerated. If the kernel does not have valid information to populate these entries with, an empty string is returned to userspace. Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Steve Capper <steve.capper@linaro.org> [suzuki.poulose@arm.com: ABI documentation updates, hotplug notifiers, kobject changes] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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1b028984 |
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22-Mar-2016 |
Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> |
cpufreq: powernv: Add sysfs attributes to show throttle stats Create sysfs attributes to export throttle information in /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory. The newly added sysfs files are as follows: 1)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat 2)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub-turbo_stat 3)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle 4)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap 5)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp 6)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault 7)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent 8)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset Detailed explanation of each attribute is added to Documentation/ABI/testing/sysfs-devices-system-cpu Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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2539b258 |
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08-May-2015 |
Will Deacon <will@kernel.org> |
drivers/base: cacheinfo: fix annoying typo when DT nodes are absent s/hierarcy/hierarchy/ Maybe the typo will annoy people enough so that they add the missing nodes to their device-tree files, but I still think this is better off fixed. Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ea8e080b |
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18-May-2015 |
Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> |
x86/Documentation: Update the contact email for L3 cache index disable functionality The mailing list discuss@x86-64.org is now defunct. Use the lkml in its place. Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Greg KH <greg@kroah.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> Cc: linux-api@vger.kernel.org Cc: sboyd@codeaurora.org Cc: sudeep.holla@arm.com Link: http://lkml.kernel.org/r/1431125098-9470-1-git-send-email-Aravind.Gopalakrishnan@amd.com Link: http://lkml.kernel.org/r/1431936437-25286-2-git-send-email-bp@alien8.de [ Changed the contact email to lkml. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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246246cb |
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30-Sep-2014 |
Sudeep Holla <sudeep.holla@arm.com> |
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dec102aa |
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21-Apr-2014 |
Viresh Kumar <viresh.kumar@linaro.org> |
cpufreq: Make linux-pm@vger.kernel.org official mailing list There has been confusion all the time about which mailing list to follow for cpufreq activities, linux-pm@vger.kernel.org or cpufreq@vger.kernel.org. Since patches sent to cpufreq@vger.kernel.org don't go to Patchwork which is a maintenance workflow problem, make linux-pm@vger.kernel.org the official mailing list for cpufreq stuff and remove all references of cpufreq@vger.kernel.org from kernel source. Later, we can request that the list be dropped entirely. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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fbe299e0 |
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06-Jan-2014 |
Ramkumar Ramachandra <artagnon@gmail.com> |
Documentation: add ABI entry for intel_pstate Add a Documentation/ABI entry for /sys/devices/system/cpu/intel_pstate/max_perf_pct, /sys/devices/system/cpu/intel_pstate/min_perf_pct, and /sys/devices/system/cpu/intel_pstate/no_turbo. Cc: Dirk Brandewie <dirk.brandewie@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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f4fd3797 |
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27-Jun-2013 |
Lan Tianyu <tianyu.lan@intel.com> |
acpi-cpufreq: Add new sysfs attribute freqdomain_cpus Commits fcf8058 (cpufreq: Simplify cpufreq_add_dev()) and aa77a52 (cpufreq: acpi-cpufreq: Don't set policy->related_cpus from .init()) changed the contents of the "related_cpus" sysfs attribute on systems where acpi-cpufreq is used and user space can't get the list of CPUs which are in the same hardware coordination CPU domain (provided by the ACPI AML method _PSD) via "related_cpus" any more. To make up for that loss add a new sysfs attribute "freqdomian_cpus" for the acpi-cpufreq driver which exposes the list of CPUs in the same domain regardless of whether it is coordinated by hardware or software. [rjw: Changelog, documentation] References: https://bugzilla.kernel.org/show_bug.cgi?id=58761 Reported-by: Jean-Philippe Halimi <jean-philippe.halimi@exascale-computing.eu> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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c4fd675f |
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28-Mar-2013 |
Zhang Yanfei <zhangyanfei@cn.fujitsu.com> |
Documentation: Add ABI entry for crash_notes and crash_notes_size Add an Documentation/ABI entry for /sys/devices/system/cpu/cpu0/crash_notes and /sys/devices/system/cpu/cpu0/crash_notes_size. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Simon Horman <horms@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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145bfa9d |
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03-Jan-2013 |
Kusanagi Kouichi <slash@ac.auone-net.jp> |
Revert "Documentation: ABI: /sys/devices/system/cpu/cpu#/node" This reverts commit cba5dd7fa535b7684cba68e17ac8be5b0083dc3d. Commit cba5dd7fa535b7684cba68e17ac8be5b0083dc3d duplicates /sys/devices/system/cpu/cpu#/node entry. Commit 657348a056eea4a27be20cf8e22c98a252597447 has already added it. Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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615b7300 |
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04-Sep-2012 |
Andre Przywara <andre.przywara@amd.com> |
acpi-cpufreq: Add support for disabling dynamic overclocking One feature present in powernow-k8 that isn't present in acpi-cpufreq is support for enabling or disabling AMD's core performance boost technology. This patch adds support to acpi-cpufreq, but also includes support for Intel's dynamic acceleration. The original boost disabling sysfs file was per CPU, but acted globally. Also the naming (cpb) was at least not intuitive. So lets introduce a single file simply called "boost", which sits once in /sys/devices/system/cpu/cpufreq. This should be the only way of using this feature, so add documentation about the rationale and the usage. A following patch will re-introduce the cpb knob for compatibility reasons on AMD CPUs. Per-CPU boost switching is possible, but not trivial and is thus postponed to a later patch series. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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8e7fbcbc |
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09-Jan-2012 |
Peter Zijlstra <peterz@infradead.org> |
sched: Remove stale power aware scheduling remnants and dysfunctional knobs It's been broken forever (i.e. it's not scheduling in a power aware fashion), as reported by Suresh and others sending patches, and nobody cares enough to fix it properly ... so remove it to make space free for something better. There's various problems with the code as it stands today, first and foremost the user interface which is bound to topology levels and has multiple values per level. This results in a state explosion which the administrator or distro needs to master and almost nobody does. Furthermore large configuration state spaces aren't good, it means the thing doesn't just work right because it's either under so many impossibe to meet constraints, or even if there's an achievable state workloads have to be aware of it precisely and can never meet it for dynamic workloads. So pushing this kind of decision to user-space was a bad idea even with a single knob - it's exponentially worse with knobs on every node of the topology. There is a proposal to replace the user interface with a single 3 state knob: sched_balance_policy := { performance, power, auto } where 'auto' would be the preferred default which looks at things like Battery/AC mode and possible cpufreq state or whatever the hw exposes to show us power use expectations - but there's been no progress on it in the past many months. Aside from that, the actual implementation of the various knobs is known to be broken. There have been sporadic attempts at fixing things but these always stop short of reaching a mergable state. Therefore this wholesale removal with the hopes of spurring people who care to come forward once again and work on a coherent replacement. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
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eecaaba5 |
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16-May-2011 |
Borislav Petkov <borislav.petkov@amd.com> |
Documentation, ABI: Update L3 cache index disable text Change contact person to AMD kernel mailing list, update text and external references, drop "Users:" tag. Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1305553188-21061-4-git-send-email-bp@amd64.org Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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0ea6e611 |
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23-Jul-2010 |
Justin P. Mattock <justinmattock@gmail.com> |
Documentation: update broken web addresses. Below you will find an updated version from the original series bunching all patches into one big patch updating broken web addresses that are located in Documentation/* Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult, the best way to deal with these is to use web.archive.org to locate these addresses that are outdated. Now there are also some addresses pointing to .spec files some are located, but some(after searching on the companies site)where still no where to be found. In this case I just changed the address to the company site this way the users can contact the company and they can locate them for the users. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Thomas Weber <weber@corscience.de> Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Cc: Paulo Marques <pmarques@grupopie.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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cba5dd7f |
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14-Dec-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: /sys/devices/system/cpu/cpu#/node Describe NUMA node symlink created for CPUs when CONFIG_NUMA is set. Signed-off-by: Alex Chiang <achiang@hp.com> Cc: Greg KH <greg@kroah.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Gary Hade <garyhade@us.ibm.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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12633e80 |
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25-Nov-2009 |
Nathan Fontenot <nfont@austin.ibm.com> |
sysfs/cpu: Add probe/release files Version 3 of this patch is updated with documentation added to Documentation/ABI. There are no changes to any of the C code from v2 of the patch. In order to support kernel DLPAR of CPU resources we need to provide an interface to add (probe) and remove (release) the resource from the system. This patch Creates new generic probe and release sysfs files to facilitate cpu probe/release. The probe/release interface provides for allowing each arch to supply their own routines for implementing the backend of adding and removing cpus to/from the system. This also creates the powerpc specific stubs to handle the arch callouts from writes to the sysfs files. The creation and use of these files is regulated by the CONFIG_ARCH_CPU_PROBE_RELEASE option so that only architectures that need the capability will have the files created. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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0cda8b91 |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
[CPUFREQ] Documentation: ABI: /sys/devices/system/cpu/cpu#/cpufreq/ This is a complex interface and is already described in Documentation/cpu-freq/, especially in the user-guide.txt file. No need to copy/paste all that information. Let's just alert the reader to the presence of the user-guide. Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Dave Jones <davej@redhat.com>
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657348a0 |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: /sys/devices/system/cpu/cpu#/node Describe NUMA node symlink created for CPUs when CONFIG_NUMA is set. Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c1fb5c47 |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: /sys/devices/system/cpu/cpuidle/ Document cpuidle sysfs attributes by reading code, Documentation/cpuidle/, and git logs. Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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e6dcfa7c |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: /sys/devices/system/cpu/sched_[mc|smt]_power_savings Document sched_[mc|smt]_power_savings by reading existing code and git logs. Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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663fb2fc |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: /sys/devices/system/cpu/cpu#/ topology files Add brief descriptions for the following sysfs files: /sys/devices/system/cpu/cpu#/topology/core_id /sys/devices/system/cpu/cpu#/topology/core_siblings /sys/devices/system/cpu/cpu#/topology/core_siblings_list /sys/devices/system/cpu/cpu#/topology/physical_package_id /sys/devices/system/cpu/cpu#/topology/thread_siblings /sys/devices/system/cpu/cpu#/topology/thread_siblings_list The descriptions in Documentation/cputopology.txt weren't very informative, so I attempted a better description based on code reading and hopeful guessing. Updated Documentation/cputopology.txt with the better descriptions and fixed some style issues. Cc: Mike Travis <travis@sgi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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d93fc863 |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: /sys/devices/system/cpu/ topology files Add brief descriptions for the following sysfs files: /sys/devices/system/cpu/kernel_max /sys/devices/system/cpu/offline /sys/devices/system/cpu/online /sys/devices/system/cpu/possible /sys/devices/system/cpu/present Excerpted the relevant information from Documentation/cputopology.txt and pointed back to cputopology.txt as the authoritative source of information. Cc: Mike Travis <travis@sgi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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2ceb3fb0 |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: document /sys/devices/system/cpu/ This interface has been around for a long time, but hasn't been officially documented. Document the top level sysfs directory for CPU attributes. Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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468727ab |
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21-Oct-2009 |
Alex Chiang <achiang@hp.com> |
Documentation: ABI: rename sysfs-devices-cache_disable properly Rename sysfs-devices-cache_disable to sysfs-devices-system-cpu, in order to keep a stricter correlation between a sysfs directory and its documentation. Reported-by: David Rientjes <rientjes@google.com> Signed-off-by: Alex Chiang <achiang@hp.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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