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2020-07-22arch_topology, sched/core: Cleanup thermal pressure definitionValentin Schneider
The following commit: 14533a16c46d ("thermal/cpu-cooling, sched/core: Move the arch_set_thermal_pressure() API to generic scheduler code") moved the definition of arch_set_thermal_pressure() to sched/core.c, but kept its declaration in linux/arch_topology.h. When building e.g. an x86 kernel with CONFIG_SCHED_THERMAL_PRESSURE=y, cpufreq_cooling.c ends up getting the declaration of arch_set_thermal_pressure() from include/linux/arch_topology.h, which is somewhat awkward. On top of this, sched/core.c unconditionally defines o The thermal_pressure percpu variable o arch_set_thermal_pressure() while arch_scale_thermal_pressure() does nothing unless redefined by the architecture. arch_*() functions are meant to be defined by architectures, so revert the aforementioned commit and re-implement it in a way that keeps arch_set_thermal_pressure() architecture-definable, and doesn't define the thermal pressure percpu variable for kernels that don't need it (CONFIG_SCHED_THERMAL_PRESSURE=n). Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200712165917.9168-2-valentin.schneider@arm.com
2020-03-31Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "The bulk is in-kernel pointer authentication, activity monitors and lots of asm symbol annotations. I also queued the sys_mremap() patch commenting the asymmetry in the address untagging. Summary: - In-kernel Pointer Authentication support (previously only offered to user space). - ARM Activity Monitors (AMU) extension support allowing better CPU utilisation numbers for the scheduler (frequency invariance). - Memory hot-remove support for arm64. - Lots of asm annotations (SYM_*) in preparation for the in-kernel Branch Target Identification (BTI) support. - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the PMU init callbacks, support for new DT compatibles. - IPv6 header checksum optimisation. - Fixes: SDEI (software delegated exception interface) double-lock on hibernate with shared events. - Minor clean-ups and refactoring: cpu_ops accessor, cpu_do_switch_mm() converted to C, cpufeature finalisation helper. - sys_mremap() comment explaining the asymmetric address untagging behaviour" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits) mm/mremap: Add comment explaining the untagging behaviour of mremap() arm64: head: Convert install_el2_stub to SYM_INNER_LABEL arm64: Introduce get_cpu_ops() helper function arm64: Rename cpu_read_ops() to init_cpu_ops() arm64: Declare ACPI parking protocol CPU operation if needed arm64: move kimage_vaddr to .rodata arm64: use mov_q instead of literal ldr arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH lkdtm: arm64: test kernel pointer authentication arm64: compile the kernel with ptrauth return address signing kconfig: Add support for 'as-option' arm64: suspend: restore the kernel ptrauth keys arm64: __show_regs: strip PAC from lr in printk arm64: unwind: strip PAC from kernel addresses arm64: mask PAC bits of __builtin_return_address arm64: initialize ptrauth keys for kernel booting task arm64: initialize and switch ptrauth kernel keys arm64: enable ptrauth earlier arm64: cpufeature: handle conflicts based on capability arm64: cpufeature: Move cpu capability helpers inside C file ...
2020-03-06arm64: use activity monitors for frequency invarianceIonela Voinescu
The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. So far, for arm and arm64 platforms, this scale factor has been obtained based on the ratio between the current frequency and the maximum supported frequency recorded by the cpufreq policy. The setting of this scale factor is triggered from cpufreq drivers by calling arch_set_freq_scale. The current frequency used in computation is the frequency requested by a governor, but it may not be the frequency that was implemented by the platform. This correction factor can also be obtained using a core counter and a constant counter to get information on the performance (frequency based only) obtained in a period of time. This will more accurately reflect the actual current frequency of the CPU, compared with the alternative implementation that reflects the request of a performance level from the OS. Therefore, implement arch_scale_freq_tick to use activity monitors, if present, for the computation of the frequency scale factor. The use of AMU counters depends on: - CONFIG_ARM64_AMU_EXTN - depents on the AMU extension being present - CONFIG_CPU_FREQ - the current frequency obtained using counter information is divided by the maximum frequency obtained from the cpufreq policy. While it is possible to have a combination of CPUs in the system with and without support for activity monitors, the use of counters for frequency invariance is only enabled for a CPU if all related CPUs (CPUs in the same frequency domain) support and have enabled the core and constant activity monitor counters. In this way, there is a clear separation between the policies for which arch_set_freq_scale (cpufreq based FIE) is used, and the policies for which arch_scale_freq_tick (counter based FIE) is used to set the frequency scale factor. For this purpose, a late_initcall_sync is registered to trigger validation work for policies that will enable or disable the use of AMU counters for frequency invariance. If CONFIG_CPU_FREQ is not defined, the use of counters is enabled on all CPUs only if all possible CPUs correctly support the necessary counters. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-06arm64/topology: Populate arch_scale_thermal_pressure() for arm64 platformsThara Gopinath
Hook up topology_get_thermal_pressure to arch_scale_thermal_pressure thus enabling scheduler to retrieve instantaneous thermal pressure of a CPU. Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20200222005213.3873-5-thara.gopinath@linaro.org
2019-07-22cpu-topology: Move cpu topology code to common code.Atish Patra
Both RISC-V & ARM64 are using cpu-map device tree to describe their cpu topology. It's better to move the relevant code to a common place instead of duplicate code. To: Will Deacon <will.deacon@arm.com> To: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Atish Patra <atish.patra@wdc.com> [Tested on QDF2400] Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> [Tested on Juno and other embedded platforms.] Tested-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2018-09-10sched/topology, arch/arm64: Rebuild the sched_domain hierarchy when the CPU ↵Morten Rasmussen
capacity changes Asymmetric CPU capacity can not necessarily be determined accurately at the time the initial sched_domain hierarchy is built during boot. It is therefore necessary to be able to force a full rebuild of the hierarchy later triggered by the arch_topology driver. A full rebuild requires the arch-code to implement arch_update_cpu_topology() which isn't yet implemented for arm64. This patch points the arm64 implementation to arch_topology driver to ensure that full hierarchy rebuild happens when needed. Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: dietmar.eggemann@arm.com Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1532093554-30504-4-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-06arm64: topology: rename llc_siblings to align with other struct membersSudeep Holla
Similar to core_sibling and thread_sibling, it's better to align and rename llc_siblings to llc_sibling. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Tested-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-06arm64: topology: add support to remove cpu topology sibling masksSudeep Holla
This patch adds support to remove all the CPU topology information using clear_cpu_topology and also resetting the sibling information on other sibling CPUs. This will be used in cpu_disable so that all the topology sibling information is removed on CPU hotplug out. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Tested-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-05-17arm64: topology: divorce MC scheduling domain from core_siblingsJeremy Linton
Now that we have an accurate view of the physical topology we need to represent it correctly to the scheduler. Generally MC should equal the LLC in the system, but there are a number of special cases that need to be dealt with. In the case of NUMA in socket, we need to assure that the sched domain we build for the MC layer isn't larger than the DIE above it. Similarly for LLC's that might exist in cross socket interconnect or directory hardware we need to assure that MC is shrunk to the socket or NUMA node. This patch builds a sibling mask for the LLC, and then picks the smallest of LLC, socket siblings, or NUMA node siblings, which gives us the behavior described above. This is ever so slightly different than the similar alternative where we look for a cache layer less than or equal to the socket/NUMA siblings. The logic to pick the MC layer affects all arm64 machines, but only changes the behavior for DT/MPIDR systems if the NUMA domain is smaller than the core siblings (generally set to the cluster). Potentially this fixes a possible bug in DT systems, but really it only affects ACPI systems where the core siblings is correctly set to the socket siblings. Thus all currently available ACPI systems should have MC equal to LLC, including the NUMA in socket machines where the LLC is partitioned between the NUMA nodes. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Vijaya Kumar K <vkilari@codeaurora.org> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17arm64: topology: rename cluster_idJeremy Linton
The cluster concept isn't architecturally defined for arm64. Lets match the name of the arm64 topology field to the kernel macro that uses it. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Vijaya Kumar K <vkilari@codeaurora.org> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-11-13Merge branch 'pm-cpufreq'Rafael J. Wysocki
* pm-cpufreq: (22 commits) cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE cpufreq: arm_big_little: make cpufreq_arm_bL_ops structures const cpufreq: arm_big_little: make function arguments and structure pointer const cpufreq: pxa: convert to clock API cpufreq: speedstep-lib: mark expected switch fall-through cpufreq: ti-cpufreq: add missing of_node_put() cpufreq: dt: Remove support for Exynos4212 SoCs cpufreq: imx6q: Move speed grading check to cpufreq driver cpufreq: ti-cpufreq: kfree opp_data when failure cpufreq: SPEAr: pr_err() strings should end with newlines cpufreq: powernow-k8: pr_err() strings should end with newlines cpufreq: dt-platdev: drop socionext,uniphier-ld6b from whitelist arm64: wire cpu-invariant accounting support up to the task scheduler arm64: wire frequency-invariant accounting support up to the task scheduler arm: wire cpu-invariant accounting support up to the task scheduler arm: wire frequency-invariant accounting support up to the task scheduler drivers base/arch_topology: allow inlining cpu-invariant accounting support drivers base/arch_topology: provide frequency-invariant accounting support cpufreq: dt: invoke frequency-invariance setter function cpufreq: arm_big_little: invoke frequency-invariance setter function ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-03arm64: wire cpu-invariant accounting support up to the task schedulerDietmar Eggemann
Commit 8cd5601c5060 ("sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define") changed the wiring which now has to be done by associating arch_scale_cpu_capacity with the actual implementation provided by the architecture. Define arch_scale_cpu_capacity to use the arch_topology "driver" function topology_get_cpu_scale() for the task scheduler's cpu-invariant accounting instead of the default arch_scale_cpu_capacity() in kernel/sched/sched.h. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Reviewed-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-03arm64: wire frequency-invariant accounting support up to the task schedulerDietmar Eggemann
Commit dfbca41f3479 ("sched: Optimize freq invariant accounting") changed the wiring which now has to be done by associating arch_scale_freq_capacity with the actual implementation provided by the architecture. Define arch_scale_freq_capacity to use the arch_topology "driver" function topology_get_freq_scale() for the task scheduler's frequency-invariant accounting instead of the default arch_scale_freq_capacity() in kernel/sched/sched.h. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Reviewed-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-15arm64, numa: Add NUMA support for arm64 platforms.Ganapatrao Kulkarni
Attempt to get the memory and CPU NUMA node via of_numa. If that fails, default the dummy NUMA node and map all memory and CPUs to node 0. Tested-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Robert Richter <rrichter@cavium.com> Signed-off-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: force CONFIG_SMP=y and remove redundant #ifdefsWill Deacon
Nobody seems to be producing !SMP systems anymore, so this is just becoming a source of kernel bugs, particularly if people want to use coherent DMA with non-shared pages. This patch forces CONFIG_SMP=y for arm64, removing a modest amount of code in the process. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-05-27sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask()Bartosz Golaszewski
Rename topology_thread_cpumask() to topology_sibling_cpumask() for more consistency with scheduler code. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Benoit Cousson <bcousson@baylibre.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jean Delvare <jdelvare@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/1432645896-12588-2-git-send-email-bgolaszewski@baylibre.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-16arm64: sched: Remove unused mc_capable() and smt_capable()Zi Shen Lim
Remove unused and deprecated mc_capable() and smt_capable(). Both were added recently by f6e763b93a6c ("arm64: topology: Implement basic CPU topology support"). Uses of both were removed by 8e7fbcbc22c1 ("sched: Remove stale power aware scheduling remnants and dysfunctional knobs"). Signed-off-by: Zi Shen Lim <zlim@broadcom.com> Signed-off-by: Mark Brown <broonie@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-04arm64: topology: Implement basic CPU topology supportMark Brown
Add basic CPU topology support to arm64, based on the existing pre-v8 code and some work done by Mark Hambleton. This patch does not implement any topology discovery support since that should be based on information from firmware, it merely implements the scaffolding for integration of topology support in the architecture. No locking of the topology data is done since it is only modified during CPU bringup with external serialisation from the SMP code. The goal is to separate the architecture hookup for providing topology information from the DT parsing in order to ease review and avoid blocking the architecture code (which will be built on by other work) with the DT code review by providing something simple and basic. Following patches will implement support for interpreting topology information from MPIDR and for parsing the DT topology bindings for ARM, similar patches will be needed for ACPI. Signed-off-by: Mark Brown <broonie@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> [catalin.marinas@arm.com: removed CONFIG_CPU_TOPOLOGY, always on if SMP] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>