pm24.git/include/linux/cpu.h, branch v6.8-rc1

drivers: base: add arch_cpu_is_hotpluggable()

2023-12-06T03:41:48Z

The differences between architecture specific implementations of arch_register_cpu() are down to whether the CPU is hotpluggable or not. Rather than overriding the weak version of arch_register_cpu(), provide a function that can be used to provide this detail instead. Reviewed-by: Shaoqin Huang Signed-off-by: "Russell King (Oracle)" Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/E1r5R3M-00CszH-6r@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman

drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden

2023-12-06T03:41:48Z

Architectures often have extra per-cpu work that needs doing before a CPU is registered, often to determine if a CPU is hotpluggable. To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move the cpu_register() call into arch_register_cpu(), which is made __weak so architectures with extra work can override it. This aligns with the way x86, ia64 and loongarch register hotplug CPUs when they become present. Signed-off-by: James Morse Reviewed-by: Shaoqin Huang Reviewed-by: Gavin Shan Signed-off-by: "Russell King (Oracle)" Reviewed-by: Jonathan Cameron Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/E1r5R3B-00Csz6-Uh@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman

Merge tag 'v6.6-rc7' into sched/core, to pick up fixes

2023-10-23T09:32:25Z

Pick up recent sched/urgent fixes merged upstream. Signed-off-by: Ingo Molnar

cpu-hotplug: Provide prototypes for arch CPU registration

2023-10-11T12:27:37Z

Provide common prototypes for arch_register_cpu() and arch_unregister_cpu(). These are called by acpi_processor.c, with weak versions, so the prototype for this is already set. It is generally not necessary for function prototypes to be conditional on preprocessor macros. Some architectures (e.g. Loongarch) are missing the prototype for this, and rather than add it to Loongarch's asm/cpu.h, do the job once for everyone. Since this covers everyone, remove the now unnecessary prototypes in asm/cpu.h, and therefore remove the 'static' from one of ia64's arch_register_cpu() definitions. [ tglx: Bring back the ia64 part and remove the ACPI prototypes ] Signed-off-by: Russell King (Oracle) Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/E1qkoRr-0088Q8-Da@rmk-PC.armlinux.org.uk

sched: Simplify tg_set_cfs_bandwidth()

2023-09-13T13:01:42Z

Use guards to reduce gotos and simplify control flow. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar

Merge tag 'smp-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-08-28T22:04:43Z

Pull CPU hotplug updates from Thomas Gleixner: "Updates for the CPU hotplug core: - Support partial SMT enablement. So far the sysfs SMT control only allows to toggle between SMT on and off. That's sufficient for x86 which usually has at max two threads except for the Xeon PHI platform which has four threads per core Though PowerPC has up to 16 threads per core and so far it's only possible to control the number of enabled threads per core via a command line option. There is some way to control this at runtime, but that lacks enforcement and the usability is awkward This update expands the sysfs interface and the core infrastructure to accept numerical values so PowerPC can build SMT runtime control for partial SMT enablement on top The core support has also been provided to the PowerPC maintainers who added the PowerPC related changes on top - Minor cleanups and documentation updates" * tag 'smp-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: core-api/cpuhotplug: Fix state names cpu/hotplug: Remove unused function declaration cpu_set_state_online() cpu/SMT: Fix cpu_smt_possible() comment cpu/SMT: Allow enabling partial SMT states via sysfs cpu/SMT: Create topology_smt_thread_allowed() cpu/SMT: Remove topology_smt_supported() cpu/SMT: Store the current/max number of threads cpu/SMT: Move smt/control simple exit cases earlier cpu/SMT: Move SMT prototypes into cpu_smt.h cpu/hotplug: Remove dependancy against cpu_primary_thread_mask

x86/speculation: Add cpu_show_gds() prototype

2023-08-10T16:12:18Z

The newly added function has two definitions but no prototypes: drivers/base/cpu.c:605:16: error: no previous prototype for 'cpu_show_gds' [-Werror=missing-prototypes] Add a declaration next to the other ones for this file to avoid the warning. Fixes: 8974eb588283b ("x86/speculation: Add Gather Data Sampling mitigation") Signed-off-by: Arnd Bergmann Signed-off-by: Dave Hansen Tested-by: Daniel Sneddon Cc: stable@kernel.org Link: https://lore.kernel.org/all/20230809130530.1913368-1-arnd%40kernel.org

cpu/hotplug: Remove unused function declaration cpu_set_state_online()

2023-08-07T16:22:42Z

Commit 5356297d12d9 ("cpu/hotplug: Remove cpu_report_state() and related unused cruft") removed function but leave the declaration. Signed-off-by: Yue Haibing Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230805110406.45900-1-yuehaibing@huawei.com

cpu/SMT: Move SMT prototypes into cpu_smt.h

2023-07-28T07:53:36Z

In order to export the cpuhp_smt_control enum as part of the interface between generic and architecture code, the architecture code needs to include asm/topology.h. But that leads to circular header dependencies. So split the enum and related declarations into a separate header. [ ldufour: Reworded the commit's description ] Signed-off-by: Michael Ellerman Signed-off-by: Laurent Dufour Signed-off-by: Thomas Gleixner Tested-by: Zhang Rui Link: https://lore.kernel.org/r/20230705145143.40545-3-ldufour@linux.ibm.com

x86/srso: Add a Speculative RAS Overflow mitigation

2023-07-27T09:07:14Z

Add a mitigation for the speculative return address stack overflow vulnerability found on AMD processors. The mitigation works by ensuring all RET instructions speculate to a controlled location, similar to how speculation is controlled in the retpoline sequence. To accomplish this, the __x86_return_thunk forces the CPU to mispredict every function return using a 'safe return' sequence. To ensure the safety of this mitigation, the kernel must ensure that the safe return sequence is itself free from attacker interference. In Zen3 and Zen4, this is accomplished by creating a BTB alias between the untraining function srso_untrain_ret_alias() and the safe return function srso_safe_ret_alias() which results in evicting a potentially poisoned BTB entry and using that safe one for all function returns. In older Zen1 and Zen2, this is accomplished using a reinterpretation technique similar to Retbleed one: srso_untrain_ret() and srso_safe_ret(). Signed-off-by: Borislav Petkov (AMD)