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path: root/arch/x86/kernel/smpboot.c
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2025-07-14Merge branch 'tip/sched/urgent'Peter Zijlstra
Avoid merge conflicts Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-07-14x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabledLi Chen
Currently, the SMT domain is added into sched_domain_topology by default. If cpu_attach_domain() finds that the CPU SMT domain’s cpumask_weight is just 1, it will destroy it. On a large machine, such as one with 512 cores, this results in 512 redundant domain attach/destroy operations. Avoid these unnecessary operations by simply checking cpu_smt_num_threads and skip SMT domain if the SMT domain is not enabled. Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20250710105715.66594-5-me@linux.beauty
2025-07-14x86/smpboot: moves x86_topology to static initialize and truncateLi Chen
The #ifdeffery and the initializers in build_sched_topology() are just disgusting. Statically initialize the domain levels in the topology array and let build_sched_topology() invalidate the package domain level when NUMA in package is available. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20250710105715.66594-4-me@linux.beauty
2025-07-14x86/smpboot: remove redundant CONFIG_SCHED_SMTLi Chen
On x86 CONFIG_SCHED_SMT is default y if SMP is enabled, so let's simply drop CONFIG_SCHED_SMT. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20250710105715.66594-3-me@linux.beauty
2025-07-14smpboot: introduce SDTL_INIT() helper to tidy sched topology setupLi Chen
Define a small SDTL_INIT(maskfn, flagsfn, name) macro and use it to build the sched_domain_topology_level array. Purely a cleanup; behaviour is unchanged. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20250710105715.66594-2-me@linux.beauty
2025-06-07Reapply "x86/smp: Eliminate mwait_play_dead_cpuid_hint()"Rafael J. Wysocki
Revert commit 70523f335734 ("Revert "x86/smp: Eliminate mwait_play_dead_cpuid_hint()"") to reapply the changes from commit 96040f7273e2 ("x86/smp: Eliminate mwait_play_dead_cpuid_hint()") reverted by it. Previously, these changes caused idle power to rise on systems booting with "nosmt" in the kernel command line because they effectively caused "dead" SMT siblings to remain in idle state C1 after executing the HLT instruction, which prevented the processor from reaching package idle states deeper than PC2 going forward. Now, the "dead" SMT siblings are rescanned after initializing a proper cpuidle driver for the processor (either intel_idle or ACPI idle), at which point they are able to enter a sufficiently deep idle state in native_play_dead() via cpuidle, so the code changes in question can be reapplied. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Link: https://patch.msgid.link/7813065.EvYhyI6sBW@rjwysocki.net
2025-06-03Merge tag 'hyperv-next-signed-20250602' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel) - Fixes for Hyper-V UIO driver (Long Li) - Fixes for Hyper-V PCI driver (Michael Kelley) - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley) - Documentation updates for Hyper-V VMBus (Michael Kelley) - Enhance logging for hv_kvp_daemon (Shradha Gupta) * tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits) Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir Documentation: hyperv: Update VMBus doc with new features and info PCI: hv: Remove unnecessary flex array in struct pci_packet Drivers: hv: Remove hv_alloc/free_* helpers Drivers: hv: Use kzalloc for panic page allocation uio_hv_generic: Align ring size to system page uio_hv_generic: Use correct size for interrupt and monitor pages Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary arch/x86: Provide the CPU number in the wakeup AP callback x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap() PCI: hv: Get vPCI MSI IRQ domain from DeviceTree ACPI: irq: Introduce acpi_get_gsi_dispatcher() Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device() Drivers: hv: vmbus: Get the IRQ number from DeviceTree dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties arm64, x86: hyperv: Report the VTL the system boots in arm64: hyperv: Initialize the Virtual Trust Level field Drivers: hv: Provide arch-neutral implementation of get_vtl() Drivers: hv: Enable VTL mode for arm64 ...
2025-05-30Merge branch 'pm-cpuidle'Rafael J. Wysocki
Fix an issue in the PSCI cpuidle driver introduced recently and a nasty x86 power regression introduced in 6.15: - Prevent freeing an uninitialized pointer in error path of dt_idle_state_present() in the PSCI cpuidle driver (Dan Carpenter). - Revert an x86 commit that went into 6.15 and caused idle power, including power in suspend-to-idle, to rise rather dramatically on systems booting with "nosmt" in the kernel command line (Rafael Wysocki). * pm-cpuidle: Revert "x86/smp: Eliminate mwait_play_dead_cpuid_hint()" cpuidle: psci: Fix uninitialized variable in dt_idle_state_present()
2025-05-29Revert "x86/smp: Eliminate mwait_play_dead_cpuid_hint()"Rafael J. Wysocki
Revert commit 96040f7273e2 ("x86/smp: Eliminate mwait_play_dead_cpuid_hint()") because it introduced a significant power regression on systems that start with "nosmt" in the kernel command line. Namely, on such systems, SMT siblings permanently go offline early, when cpuidle has not been initialized yet, so after the above commit, hlt_play_dead() is called for them. Later on, when the processor attempts to enter a deep package C-state, including PC10 which is requisite for reaching minimum power in suspend-to-idle, it is not able to do that because of the SMT siblings staying in C1 (which they have been put into by HLT). As a result, the idle power (including power in suspend-to-idle) rises quite dramatically on those systems with all of the possible consequences, which (needless to say) may not be expected by their users. This issue is hard to debug and potentially dangerous, so it needs to be addressed as soon as possible in a way that will work for 6.15.y, hence the revert. Of course, after this revert, the issue that commit 96040f7273e2 attempted to address will be back and it will need to be fixed again later. Fixes: 96040f7273e2 ("x86/smp: Eliminate mwait_play_dead_cpuid_hint()") Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com> Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com> Cc: 6.15+ <stable@vger.kernel.org> # 6.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/12674167.O9o76ZdvQC@rjwysocki.net
2025-05-26Merge tag 'x86-core-2025-05-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core x86 updates from Ingo Molnar: "Boot code changes: - A large series of changes to reorganize the x86 boot code into a better isolated and easier to maintain base of PIC early startup code in arch/x86/boot/startup/, by Ard Biesheuvel. Motivation & background: | Since commit | | c88d71508e36 ("x86/boot/64: Rewrite startup_64() in C") | | dated Jun 6 2017, we have been using C code on the boot path in a way | that is not supported by the toolchain, i.e., to execute non-PIC C | code from a mapping of memory that is different from the one provided | to the linker. It should have been obvious at the time that this was a | bad idea, given the need to sprinkle fixup_pointer() calls left and | right to manipulate global variables (including non-pointer variables) | without crashing. | | This C startup code has been expanding, and in particular, the SEV-SNP | startup code has been expanding over the past couple of years, and | grown many of these warts, where the C code needs to use special | annotations or helpers to access global objects. This tree includes the first phase of this work-in-progress x86 boot code reorganization. Scalability enhancements and micro-optimizations: - Improve code-patching scalability (Eric Dumazet) - Remove MFENCEs for X86_BUG_CLFLUSH_MONITOR (Andrew Cooper) CPU features enumeration updates: - Thorough reorganization and cleanup of CPUID parsing APIs (Ahmed S. Darwish) - Fix, refactor and clean up the cacheinfo code (Ahmed S. Darwish, Thomas Gleixner) - Update CPUID bitfields to x86-cpuid-db v2.3 (Ahmed S. Darwish) Memory management changes: - Allow temporary MMs when IRQs are on (Andy Lutomirski) - Opt-in to IRQs-off activate_mm() (Andy Lutomirski) - Simplify choose_new_asid() and generate better code (Borislav Petkov) - Simplify 32-bit PAE page table handling (Dave Hansen) - Always use dynamic memory layout (Kirill A. Shutemov) - Make SPARSEMEM_VMEMMAP the only memory model (Kirill A. Shutemov) - Make 5-level paging support unconditional (Kirill A. Shutemov) - Stop prefetching current->mm->mmap_lock on page faults (Mateusz Guzik) - Predict valid_user_address() returning true (Mateusz Guzik) - Consolidate initmem_init() (Mike Rapoport) FPU support and vector computing: - Enable Intel APX support (Chang S. Bae) - Reorgnize and clean up the xstate code (Chang S. Bae) - Make task_struct::thread constant size (Ingo Molnar) - Restore fpu_thread_struct_whitelist() to fix CONFIG_HARDENED_USERCOPY=y (Kees Cook) - Simplify the switch_fpu_prepare() + switch_fpu_finish() logic (Oleg Nesterov) - Always preserve non-user xfeatures/flags in __state_perm (Sean Christopherson) Microcode loader changes: - Help users notice when running old Intel microcode (Dave Hansen) - AMD: Do not return error when microcode update is not necessary (Annie Li) - AMD: Clean the cache if update did not load microcode (Boris Ostrovsky) Code patching (alternatives) changes: - Simplify, reorganize and clean up the x86 text-patching code (Ingo Molnar) - Make smp_text_poke_batch_process() subsume smp_text_poke_batch_finish() (Nikolay Borisov) - Refactor the {,un}use_temporary_mm() code (Peter Zijlstra) Debugging support: - Add early IDT and GDT loading to debug relocate_kernel() bugs (David Woodhouse) - Print the reason for the last reset on modern AMD CPUs (Yazen Ghannam) - Add AMD Zen debugging document (Mario Limonciello) - Fix opcode map (!REX2) superscript tags (Masami Hiramatsu) - Stop decoding i64 instructions in x86-64 mode at opcode (Masami Hiramatsu) CPU bugs and bug mitigations: - Remove X86_BUG_MMIO_UNKNOWN (Borislav Petkov) - Fix SRSO reporting on Zen1/2 with SMT disabled (Borislav Petkov) - Restructure and harmonize the various CPU bug mitigation methods (David Kaplan) - Fix spectre_v2 mitigation default on Intel (Pawan Gupta) MSR API: - Large MSR code and API cleanup (Xin Li) - In-kernel MSR API type cleanups and renames (Ingo Molnar) PKEYS: - Simplify PKRU update in signal frame (Chang S. Bae) NMI handling code: - Clean up, refactor and simplify the NMI handling code (Sohil Mehta) - Improve NMI duration console printouts (Sohil Mehta) Paravirt guests interface: - Restrict PARAVIRT_XXL to 64-bit only (Kirill A. Shutemov) SEV support: - Share the sev_secrets_pa value again (Tom Lendacky) x86 platform changes: - Introduce the <asm/amd/> header namespace (Ingo Molnar) - i2c: piix4, x86/platform: Move the SB800 PIIX4 FCH definitions to <asm/amd/fch.h> (Mario Limonciello) Fixes and cleanups: - x86 assembly code cleanups and fixes (Uros Bizjak) - Misc fixes and cleanups (Andi Kleen, Andy Lutomirski, Andy Shevchenko, Ard Biesheuvel, Bagas Sanjaya, Baoquan He, Borislav Petkov, Chang S. Bae, Chao Gao, Dan Williams, Dave Hansen, David Kaplan, David Woodhouse, Eric Biggers, Ingo Molnar, Josh Poimboeuf, Juergen Gross, Malaya Kumar Rout, Mario Limonciello, Nathan Chancellor, Oleg Nesterov, Pawan Gupta, Peter Zijlstra, Shivank Garg, Sohil Mehta, Thomas Gleixner, Uros Bizjak, Xin Li)" * tag 'x86-core-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (331 commits) x86/bugs: Fix spectre_v2 mitigation default on Intel x86/bugs: Restructure ITS mitigation x86/xen/msr: Fix uninitialized variable 'err' x86/msr: Remove a superfluous inclusion of <asm/asm.h> x86/paravirt: Restrict PARAVIRT_XXL to 64-bit only x86/mm/64: Make 5-level paging support unconditional x86/mm/64: Make SPARSEMEM_VMEMMAP the only memory model x86/mm/64: Always use dynamic memory layout x86/bugs: Fix indentation due to ITS merge x86/cpuid: Rename hypervisor_cpuid_base()/for_each_possible_hypervisor_cpuid_base() to cpuid_base_hypervisor()/for_each_possible_cpuid_base_hypervisor() x86/cpu/intel: Rename CPUID(0x2) descriptors iterator parameter x86/cacheinfo: Rename CPUID(0x2) descriptors iterator parameter x86/cpuid: Rename cpuid_get_leaf_0x2_regs() to cpuid_leaf_0x2() x86/cpuid: Rename have_cpuid_p() to cpuid_feature() x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID header x86/cpuid: Move CPUID(0x2) APIs into <cpuid/api.h> x86/msr: Add rdmsrl_on_cpu() compatibility wrapper x86/mm: Fix kernel-doc descriptions of various pgtable methods x86/asm-offsets: Export certain 'struct cpuinfo_x86' fields for 64-bit asm use too x86/boot: Defer initialization of VM space related global variables ...
2025-05-26x86/fpu: Fix irq_fpu_usable() to return false during CPU onliningEric Biggers
irq_fpu_usable() incorrectly returned true before the FPU is initialized. The x86 CPU onlining code can call sha256() to checksum AMD microcode images, before the FPU is initialized. Since sha256() recently gained a kernel-mode FPU optimized code path, a crash occurred in kernel_fpu_begin_mask() during hotplug CPU onlining. (The crash did not occur during boot-time CPU onlining, since the optimized sha256() code is not enabled until subsys_initcalls run.) Fix this by making irq_fpu_usable() return false before fpu__init_cpu() has run. To do this without adding any additional overhead to irq_fpu_usable(), replace the existing per-CPU bool in_kernel_fpu with kernel_fpu_allowed which tracks both initialization and usage rather than just usage. The initial state is false; FPU initialization sets it to true; kernel-mode FPU sections toggle it to false and then back to true; and CPU offlining restores it to the initial state of false. Fixes: 11d7956d526f ("crypto: x86/sha256 - implement library instead of shash") Reported-by: Ayush Jain <Ayush.Jain3@amd.com> Closes: https://lore.kernel.org/r/20250516112217.GBaCcf6Yoc6LkIIryP@fat_crate.local Signed-off-by: Eric Biggers <ebiggers@google.com> Tested-by: Ayush Jain <Ayush.Jain3@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-05-23arch/x86: Provide the CPU number in the wakeup AP callbackRoman Kisel
When starting APs, confidential guests and paravisor guests need to know the CPU number, and the pattern of using the linear search has emerged in several places. With N processors that leads to the O(N^2) time complexity. Provide the CPU number in the AP wake up callback so that one can get the CPU number in constant time. Suggested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20250507182227.7421-3-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250507182227.7421-3-romank@linux.microsoft.com>
2025-05-15x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID headerAhmed S. Darwish
The main CPUID header <asm/cpuid.h> was originally a storefront for the headers: <asm/cpuid/api.h> <asm/cpuid/leaf_0x2_api.h> Now that the latter CPUID(0x2) header has been merged into the former, there is no practical difference between <asm/cpuid.h> and <asm/cpuid/api.h>. Migrate all users to the <asm/cpuid/api.h> header, in preparation of the removal of <asm/cpuid.h>. Don't remove <asm/cpuid.h> just yet, in case some new code in -next started using it. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: x86-cpuid@lists.linux.dev Link: https://lore.kernel.org/r/20250508150240.172915-3-darwi@linutronix.de
2025-03-19x86/smpboot: Fix INIT delay assignment for extended Intel FamiliesSohil Mehta
Some old crusty CPUs need an extra delay that slows down booting. See the comment above 'init_udelay' for details. Newer CPUs don't need the delay. Right now, for Intel, Family 6 and only Family 6 skips the delay. That leaves out both the Family 15 (Pentium 4s) and brand new Family 18/19 models. The omission of Family 15 (Pentium 4s) seems like an oversight and 18/19 do not need the delay. Skip the delay on all Intel processors Family 6 and beyond. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250219184133.816753-11-sohil.mehta@intel.com
2025-03-19x86/smpboot: Remove confusing quirk usage in INIT delaySohil Mehta
Very old multiprocessor systems required a 10 msec delay between asserting and de-asserting INIT but modern processors do not require this delay. Over time the usage of the "quirk" wording while setting the INIT delay has become misleading. The code comments suggest that modern processors need to be quirked, which clears the default init_udelay of 10 msec, while legacy processors don't need the quirk and continue to use the default init_udelay. With a lot more modern processors, the wording should be inverted if at all needed. Instead, simplify the comments and the code by getting rid of "quirk" usage altogether and clarifying the following: - Old legacy processors -> Set the "legacy" 10 msec delay - Modern processors -> Do not set any delay No functional change. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250219184133.816753-10-sohil.mehta@intel.com
2025-03-04x86/percpu: Move current_task to percpu hot sectionBrian Gerst
No functional change. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Uros Bizjak <ubizjak@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250303165246.2175811-10-brgerst@gmail.com
2025-03-04x86/percpu: Move top_of_stack to percpu hot sectionBrian Gerst
No functional change. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Uros Bizjak <ubizjak@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250303165246.2175811-9-brgerst@gmail.com
2025-03-04Merge branch 'x86/asm' into x86/core, to pick up dependent commitsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-03-04x86/cpu: Get rid of the smp_store_cpu_info() indirectionThomas Gleixner
smp_store_cpu_info() is just a wrapper around identify_secondary_cpu() without further value. Move the extra bits from smp_store_cpu_info() into identify_secondary_cpu() and remove the wrapper. [ darwi: Make it compile and fix up the xen/smp_pv.c instance ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250304085152.51092-9-darwi@linutronix.de
2025-02-14x86/boot: Mark start_secondary() with __noendbrPeter Zijlstra
The handoff between the boot stubs and start_secondary() are before IBT is enabled and is definitely not subject to kCFI. As such, suppress all that for this function. Notably when the ENDBR poison would become fatal (ud1 instead of nop) this will trigger a tripple fault because we haven't set up the IDT to handle #UD yet. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20250207122546.509520369@infradead.org
2025-02-05x86/smp: Eliminate mwait_play_dead_cpuid_hint()Patryk Wlazlyn
Currently, mwait_play_dead_cpuid_hint() looks up the MWAIT hint of the deepest idle state by inspecting CPUID leaf 0x5 with the assumption that, if the number of sub-states for a given major C-state is nonzero, those sub-states are always represented by consecutive numbers starting from 0. This assumption is not based on the documented platform behavior and in fact it is not met on recent Intel platforms. For example, Intel's Sierra Forest report two C-states with two substates each in cpuid leaf 0x5: Name* target cstate target subcstate (mwait hint) =========================================================== C1 0x00 0x00 C1E 0x00 0x01 -- 0x10 ---- C6S 0x20 0x22 C6P 0x20 0x23 -- 0x30 ---- /* No more (sub)states all the way down to the end. */ =========================================================== * Names of the cstates are not included in the CPUID leaf 0x5, they are taken from the product specific documentation. Notice that hints 0x20 and 0x21 are not defined for C-state 0x20 (C6), so the existing MWAIT hint lookup in mwait_play_dead_cpuid_hint() based on the CPUID leaf 0x5 contents does not work in this case. Instead of using MWAIT hint lookup that is not guaranteed to work, make native_play_dead() rely on the idle driver for the given platform to put CPUs going offline into appropriate idle state and, if that fails, fall back to hlt_play_dead(). Accordingly, drop mwait_play_dead_cpuid_hint() altogether and make native_play_dead() call cpuidle_play_dead() instead of it unconditionally with the assumption that it will not return if it is successful. Still, in case cpuidle_play_dead() fails, call hlt_play_dead() at the end. Signed-off-by: Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/all/20250205155211.329780-5-artem.bityutskiy%40linux.intel.com
2025-02-05x86/smp: Allow calling mwait_play_dead with an arbitrary hintPatryk Wlazlyn
Introduce a helper function to allow offlined CPUs to enter idle states with a specific MWAIT hint. The new helper will be used in subsequent patches by the acpi_idle and intel_idle drivers. No functional change intended. Signed-off-by: Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/all/20250205155211.329780-2-artem.bityutskiy%40linux.intel.com
2025-01-21Merge tag 'sched-core-2025-01-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Fair scheduler (SCHED_FAIR) enhancements: - Behavioral improvements: - Untangle NEXT_BUDDY and pick_next_task() (Peter Zijlstra) - Delayed-dequeue enhancements & fixes: (Vincent Guittot) - Rename h_nr_running into h_nr_queued - Add new cfs_rq.h_nr_runnable - Use the new cfs_rq.h_nr_runnable - Removed unsued cfs_rq.h_nr_delayed - Rename cfs_rq.idle_h_nr_running into h_nr_idle - Remove unused cfs_rq.idle_nr_running - Rename cfs_rq.nr_running into nr_queued - Do not try to migrate delayed dequeue task - Fix variable declaration position - Encapsulate set custom slice in a __setparam_fair() function - Fixes: - Fix race between yield_to() and try_to_wake_up() (Tianchen Ding) - Fix CPU bandwidth limit bypass during CPU hotplug (Vishal Chourasia) - Cleanups: - Clean up in migrate_degrades_locality() to improve readability (Peter Zijlstra) - Mark m*_vruntime() with __maybe_unused (Andy Shevchenko) - Update comments after sched_tick() rename (Sebastian Andrzej Siewior) - Remove CONFIG_CFS_BANDWIDTH=n definition of cfs_bandwidth_used() (Valentin Schneider) Deadline scheduler (SCHED_DL) enhancements: - Restore dl_server bandwidth on non-destructive root domain changes (Juri Lelli) - Correctly account for allocated bandwidth during hotplug (Juri Lelli) - Check bandwidth overflow earlier for hotplug (Juri Lelli) - Clean up goto label in pick_earliest_pushable_dl_task() (John Stultz) - Consolidate timer cancellation (Wander Lairson Costa) Load-balancer enhancements: - Improve performance by prioritizing migrating eligible tasks in sched_balance_rq() (Hao Jia) - Do not compute NUMA Balancing stats unnecessarily during load-balancing (K Prateek Nayak) - Do not compute overloaded status unnecessarily during load-balancing (K Prateek Nayak) Generic scheduling code enhancements: - Use READ_ONCE() in task_on_rq_queued(), to consistently use the WRITE_ONCE() updated ->on_rq field (Harshit Agarwal) Isolated CPUs support enhancements: (Waiman Long) - Make "isolcpus=nohz" equivalent to "nohz_full" - Consolidate housekeeping cpumasks that are always identical - Remove HK_TYPE_SCHED - Unify HK_TYPE_{TIMER|TICK|MISC} to HK_TYPE_KERNEL_NOISE RSEQ enhancements: - Validate read-only fields under DEBUG_RSEQ config (Mathieu Desnoyers) PSI enhancements: - Fix race when task wakes up before psi_sched_switch() adjusts flags (Chengming Zhou) IRQ time accounting performance enhancements: (Yafang Shao) - Define sched_clock_irqtime as static key - Don't account irq time if sched_clock_irqtime is disabled Virtual machine scheduling enhancements: - Don't try to catch up excess steal time (Suleiman Souhlal) Heterogenous x86 CPU scheduling enhancements: (K Prateek Nayak) - Convert "sysctl_sched_itmt_enabled" to boolean - Use guard() for itmt_update_mutex - Move the "sched_itmt_enabled" sysctl to debugfs - Remove x86_smt_flags and use cpu_smt_flags directly - Use x86_sched_itmt_flags for PKG domain unconditionally Debugging code & instrumentation enhancements: - Change need_resched warnings to pr_err() (David Rientjes) - Print domain name in /proc/schedstat (K Prateek Nayak) - Fix value reported by hot tasks pulled in /proc/schedstat (Peter Zijlstra) - Report the different kinds of imbalances in /proc/schedstat (Swapnil Sapkal) - Move sched domain name out of CONFIG_SCHED_DEBUG (Swapnil Sapkal) - Update Schedstat version to 17 (Swapnil Sapkal)" * tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) rseq: Fix rseq unregistration regression psi: Fix race when task wakes up before psi_sched_switch() adjusts flags sched, psi: Don't account irq time if sched_clock_irqtime is disabled sched: Don't account irq time if sched_clock_irqtime is disabled sched: Define sched_clock_irqtime as static key sched/fair: Do not compute overloaded status unnecessarily during lb sched/fair: Do not compute NUMA Balancing stats unnecessarily during lb x86/topology: Use x86_sched_itmt_flags for PKG domain unconditionally x86/topology: Remove x86_smt_flags and use cpu_smt_flags directly x86/itmt: Move the "sched_itmt_enabled" sysctl to debugfs x86/itmt: Use guard() for itmt_update_mutex x86/itmt: Convert "sysctl_sched_itmt_enabled" to boolean sched/core: Prioritize migrating eligible tasks in sched_balance_rq() sched/debug: Change need_resched warnings to pr_err sched/fair: Encapsulate set custom slice in a __setparam_fair() function sched: Fix race between yield_to() and try_to_wake_up() docs: Update Schedstat version to 17 sched/stats: Print domain name in /proc/schedstat sched: Move sched domain name out of CONFIG_SCHED_DEBUG sched: Report the different kinds of imbalances in /proc/schedstat ...
2025-01-13x86/topology: Use x86_sched_itmt_flags for PKG domain unconditionallyK Prateek Nayak
x86_sched_itmt_flags() returns SD_ASYM_PACKING if ITMT support is enabled by the system. Without ITMT support being enabled, it returns 0 similar to current x86_die_flags() on non-Hybrid systems (!X86_HYBRID_CPU and !X86_FEATURE_AMD_HETEROGENEOUS_CORES) On Intel systems that enable ITMT support, either the MC domain coincides with the PKG domain, or in case of multiple MC groups within a PKG domain, either Sub-NUMA Cluster (SNC) is enabled or the processor features Hybrid core layout (X86_HYBRID_CPU) which leads to three distinct possibilities: o If PKG and MC domains coincide, PKG domain is degenerated by sd_parent_degenerate() when building sched domain topology. o If SNC is enabled, PKG domain is never added since "x86_has_numa_in_package" is set and the topology will instead contain NODE and NUMA domains. o On X86_HYBRID_CPU which contains multiple MC groups within the PKG, the PKG domain requires x86_sched_itmt_flags(). Thus, on Intel systems that contains multiple MC groups within the PKG and enables ITMT support, the PKG domain requires x86_sched_itmt_flags(). In all other cases PKG domain is either never added or is degenerated. Thus, returning x86_sched_itmt_flags() unconditionally at PKG domain on Intel systems should not lead to any functional changes. On AMD systems with multiple LLCs (MC groups) within a PKG domain, enabling ITMT support requires setting SD_ASYM_PACKING to the PKG domain since the core rankings are assigned PKG-wide. Core rankings on AMD processors is currently set by the amd-pstate driver when Preferred Core feature is supported. A subset of systems that support Preferred Core feature can be detected using X86_FEATURE_AMD_HETEROGENEOUS_CORES however, this does not cover all the systems that support Preferred Core ranking. Detecting Preferred Core support on AMD systems requires inspecting CPPC Highest Perf on all present CPUs and checking if it differs on at least one CPU. Previous suggestion to use a synthetic feature to detect Preferred Core support [1] was found to be non-trivial to implement since BSP alone cannot detect if Preferred Core is supported and by the time AP comes up, alternatives are patched and setting a X86_FEATURE_* then is not possible. Since x86 processors enabling ITMT support that consists multiple non-NUMA MC groups within a PKG requires SD_ASYM_PACKING flag set at the PKG domain, return x86_sched_itmt_flags unconditionally for the PKG domain. Since x86_die_flags() would have just returned x86_sched_itmt_flags() after the change, remove the unnecessary wrapper and pass x86_sched_itmt_flags() directly as the flags function. Fixes: f3a052391822 ("cpufreq: amd-pstate: Enable amd-pstate preferred core support") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Link: https://lore.kernel.org/r/20241223043407.1611-6-kprateek.nayak@amd.com
2025-01-13x86/topology: Remove x86_smt_flags and use cpu_smt_flags directlyK Prateek Nayak
x86_*_flags() wrappers were introduced with commit d3d37d850d1d ("x86/sched: Add SD_ASYM_PACKING flags to x86 ITMT CPU") to add x86_sched_itmt_flags() in addition to the default domain flags for SMT and MC domain. commit 995998ebdebd ("x86/sched: Remove SD_ASYM_PACKING from the SMT domain flags") removed the ITMT flags for SMT domain but not the x86_smt_flags() wrappers which directly returns cpu_smt_flags(). Remove x86_smt_flags() and directly use cpu_smt_flags() to derive the flags for SMT domain. No functional changes intended. Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Link: https://lore.kernel.org/r/20241223043407.1611-5-kprateek.nayak@amd.com
2024-12-18x86/cpu: Make all all CPUID leaf names consistentDave Hansen
The leaf names are not consistent. Give them all a CPUID_LEAF_ prefix for consistency and vertical alignment. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Dave Jiang <dave.jiang@intel.com> # for ioatdma bits Link: https://lore.kernel.org/all/20241213205040.7B0C3241%40davehans-spike.ostc.intel.com
2024-12-18x86/cpu: Remove unnecessary MwAIT leaf checksDave Hansen
The CPUID leaf dependency checker will remove X86_FEATURE_MWAIT if the CPUID level is below the required level (CPUID_MWAIT_LEAF). Thus, if you check X86_FEATURE_MWAIT you do not need to also check the CPUID level. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/20241213205030.9B42B458%40davehans-spike.ostc.intel.com
2024-12-18x86/cpu: Move MWAIT leaf definition to common headerDave Hansen
Begin constructing a common place to keep all CPUID leaf definitions. Move CPUID_MWAIT_LEAF to the CPUID header and include it where needed. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Zhao Liu <zhao1.liu@intel.com> Link: https://lore.kernel.org/all/20241213205028.EE94D02A%40davehans-spike.ostc.intel.com
2024-10-25x86/cpu: Enable SD_ASYM_PACKING for PKG domain on AMDPerry Yuan
Enable the SD_ASYM_PACKING domain flag for the PKG domain on AMD heterogeneous processors. This flag is beneficial for processors with one or more CCDs and relies on x86_sched_itmt_flags(). Signed-off-by: Perry Yuan <perry.yuan@amd.com> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Link: https://lore.kernel.org/r/20241025171459.1093-4-mario.limonciello@amd.com
2024-09-19Merge tag 'for-linus-6.12-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - fix a boot problem as a Xen dom0 on some AMD systems - fix Xen PVH boot problems with KASAN enabled - fix for a build warning - fixes to swiotlb-xen * tag 'for-linus-6.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/swiotlb: fix allocated size xen/swiotlb: add alignment check for dma buffers xen/pci: Avoid -Wflex-array-member-not-at-end warning xen/xenbus: Convert to use ERR_CAST() xen, pvh: fix unbootable VMs by inlining memset() in xen_prepare_pvh() x86/cpu: fix unbootable VMs by inlining memcmp() in hypervisor_cpuid_base() xen, pvh: fix unbootable VMs (PVH + KASAN - AMD_MEM_ENCRYPT) xen: tolerate ACPI NVS memory overlapping with Xen allocated memory xen: allow mapping ACPI data using a different physical address xen: add capability to remap non-RAM pages to different PFNs xen: move max_pfn in xen_memory_setup() out of function scope xen: move checks for e820 conflicts further up xen: introduce generic helper checking for memory map conflicts xen: use correct end address of kernel for conflict checking
2024-09-12xen: allow mapping ACPI data using a different physical addressJuergen Gross
When running as a Xen PV dom0 the system needs to map ACPI data of the host using host physical addresses, while those addresses can conflict with the guest physical addresses of the loaded linux kernel. The same problem might apply in case a PV guest is configured to use the host memory map. This conflict can be solved by mapping the ACPI data to a different guest physical address, but mapping the data via acpi_os_ioremap() must still be possible using the host physical address, as this address might be generated by AML when referencing some of the ACPI data. When configured to support running as a Xen PV domain, have an implementation of acpi_os_ioremap() being aware of the possibility to need above mentioned translation of a host physical address to the guest physical address. This modification requires to #include linux/acpi.h in some sources which need to include asm/acpi.h directly. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2024-08-13x86/fred: Enable FRED right after init_mem_mapping()Xin Li (Intel)
On 64-bit init_mem_mapping() relies on the minimal page fault handler provided by the early IDT mechanism. The real page fault handler is installed right afterwards into the IDT. This is problematic on CPUs which have X86_FEATURE_FRED set because the real page fault handler retrieves the faulting address from the FRED exception stack frame and not from CR2, but that does obviously not work when FRED is not yet enabled in the CPU. To prevent this enable FRED right after init_mem_mapping() without interrupt stacks. Those are enabled later in trap_init() after the CPU entry area is set up. [ tglx: Encapsulate the FRED details ] Fixes: 14619d912b65 ("x86/fred: FRED entry/exit and dispatch code") Reported-by: Hou Wenlong <houwenlong.hwl@antgroup.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240709154048.3543361-4-xin@zytor.com
2024-04-29x86/cpu: Switch to new Intel CPU model definesTony Luck
New CPU #defines encode vendor and family as well as model. [ dhansen: vertically align macro and remove stray subject / ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/all/20240424181516.41887-1-tony.luck%40intel.com
2024-04-10x86/cpu: Improve readability of per-CPU cpumask initialization codeIngo Molnar
In smp_prepare_cpus_common() and x2apic_prepare_cpu(): - use 'cpu' instead of 'i' - use 'node' instead of 'n' - use vertical alignment to improve readability - better structure basic blocks - reduce col80 checkpatch damage Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org
2024-04-10x86/cpu: Take NUMA node into account when allocating per-CPU cpumasksLi RongQing
per-CPU cpumasks are dominantly accessed from their own local CPUs, so allocate them node-local to improve performance. [ mingo: Rewrote the changelog. ] Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240410030114.6201-1-lirongqing@baidu.com
2024-03-23x86/cpu: Ensure that CPU info updates are propagated on UPThomas Gleixner
The boot sequence evaluates CPUID information twice: 1) During early boot 2) When finalizing the early setup right before mitigations are selected and alternatives are patched. In both cases the evaluation is stored in boot_cpu_data, but on UP the copying of boot_cpu_data to the per CPU info of the boot CPU happens between #1 and #2. So any update which happens in #2 is never propagated to the per CPU info instance. Consolidate the whole logic and copy boot_cpu_data right before applying alternatives as that's the point where boot_cpu_data is in it's final state and not supposed to change anymore. This also removes the voodoo mb() from smp_prepare_cpus_common() which had absolutely no purpose. Fixes: 71eb4893cfaf ("x86/percpu: Cure per CPU madness on UP") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20240322185305.127642785@linutronix.de
2024-03-11Merge tag 'x86-cleanups-2024-03-11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups, including a large series from Thomas Gleixner to cure sparse warnings" * tag 'x86-cleanups-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/nmi: Drop unused declaration of proc_nmi_enabled() x86/callthunks: Use EXPORT_PER_CPU_SYMBOL_GPL() for per CPU variables x86/cpu: Provide a declaration for itlb_multihit_kvm_mitigation x86/cpu: Use EXPORT_PER_CPU_SYMBOL_GPL() for x86_spec_ctrl_current x86/uaccess: Add missing __force to casts in __access_ok() and valid_user_address() x86/percpu: Cure per CPU madness on UP smp: Consolidate smp_prepare_boot_cpu() x86/msr: Add missing __percpu annotations x86/msr: Prepare for including <linux/percpu.h> into <asm/msr.h> perf/x86/amd/uncore: Fix __percpu annotation x86/nmi: Remove an unnecessary IS_ENABLED(CONFIG_SMP) x86/apm_32: Remove dead function apm_get_battery_status() x86/insn-eval: Fix function param name in get_eff_addr_sib()
2024-03-04x86/percpu: Cure per CPU madness on UPThomas Gleixner
On UP builds Sparse complains rightfully about accesses to cpu_info with per CPU accessors: cacheinfo.c:282:30: sparse: warning: incorrect type in initializer (different address spaces) cacheinfo.c:282:30: sparse: expected void const [noderef] __percpu *__vpp_verify cacheinfo.c:282:30: sparse: got unsigned int * The reason is that on UP builds cpu_info which is a per CPU variable on SMP is mapped to boot_cpu_info which is a regular variable. There is a hideous accessor cpu_data() which tries to hide this, but it's not sufficient as some places require raw accessors and generates worse code than the regular per CPU accessors. Waste sizeof(struct x86_cpuinfo) memory on UP and provide the per CPU cpu_info unconditionally. This requires to update the CPU info on the boot CPU as SMP does. (Ab)use the weakly defined smp_prepare_boot_cpu() function and implement exactly that. This allows to use regular per CPU accessors uncoditionally and paves the way to remove the cpu_data() hackery. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240304005104.622511517@linutronix.de
2024-03-04smp: Consolidate smp_prepare_boot_cpu()Thomas Gleixner
There is no point in having seven architectures implementing the same empty stub. Provide a weak function in the init code and remove the stubs. This also allows to utilize the function on UP which is required to sanitize the per CPU handling on X86 UP. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240304005104.567671691@linutronix.de
2024-02-16x86/cpu/topology: Get rid of cpuinfo::x86_max_coresThomas Gleixner
Now that __num_cores_per_package and __num_threads_per_package are available, cpuinfo::x86_max_cores and the related math all over the place can be replaced with the ready to consume data. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210253.176147806@linutronix.de
2024-02-15x86/cpu/topology: Rename smp_num_siblingsThomas Gleixner
It's really a non-intuitive name. Rename it to __max_threads_per_core which is obvious. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210253.011307973@linutronix.de
2024-02-15x86/cpu/topology: Use topology logical mapping mechanismThomas Gleixner
Replace the logical package and die management functionality and retrieve the logical IDs from the topology bitmaps. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210252.901865302@linutronix.de
2024-02-15x86/cpu/topology: Use topology bitmaps for sizingThomas Gleixner
Now that all possible APIC IDs are tracked in the topology bitmaps, its trivial to retrieve the real information from there. This gets rid of the guesstimates for the maximal packages and dies per package as the actual numbers can be determined before a single AP has been brought up. The number of SMT threads can now be determined correctly from the bitmaps in all situations. Up to now a system which has SMT disabled in the BIOS will still claim that it is SMT capable, because the lowest APIC ID bit is reserved for that and CPUID leaf 0xb/0x1f still enumerates the SMT domain accordingly. By calculating the bitmap weights of the SMT and the CORE domain and setting them into relation the SMT disabled in BIOS situation reports correctly that the system is not SMT capable. It also handles the situation correctly when a hybrid systems boot CPU does not have SMT as it takes the SMT capability of the APs fully into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210252.681709880@linutronix.de
2024-02-15x86/cpu/topology: Rework possible CPU managementThomas Gleixner
Managing possible CPUs is an unreadable and uncomprehensible maze. Aside of that it's backwards because it applies command line limits after registering all APICs. Rewrite it so that it: - Applies the command line limits upfront so that only the allowed amount of APIC IDs can be registered. - Applies eventual late restrictions in an understandable way - Uses simple min_t() calculations which are trivial to follow. - Provides a separate function for resetting to UP mode late in the bringup process. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210252.290098853@linutronix.de
2024-02-15x86/smpboot: Make error message actually usefulThomas Gleixner
"smpboot: native_kick_ap: bad cpu 33" is absolutely useless information. Replace it with something meaningful which allows to decode the failure condition. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210252.170806023@linutronix.de
2024-02-15x86/cpu/topology: Confine topology informationThomas Gleixner
Now that all external fiddling with num_processors and disabled_cpus is gone, move the last user prefill_possible_map() into the topology code too and remove the global visibility of these variables. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240213210251.994756960@linutronix.de
2024-02-15x86/mpparse: Remove the physid_t bitmap wrapperThomas Gleixner
physid_t is a wrapper around bitmap. Just remove the onion layer and use bitmap functionality directly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Link: https://lore.kernel.org/r/20240212154639.994904510@linutronix.de
2024-02-15x86/smpboot: Teach it about topo.amd_node_idThomas Gleixner
When switching AMD over to the new topology parser then the match functions need to look for AMD systems with the extended topology feature at the new topo.amd_node_id member which is then holding the node id information. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Wang Wendy <wendy.wang@intel.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20240212153625.082979150@linutronix.de
2023-11-17x86/smp: Export symbol cpu_clustergroup_mask()Kan Liang
Intel cstate PMU driver will invoke the topology_cluster_cpumask() to retrieve the CPU mask of a cluster. A modpost error is triggered since the symbol cpu_clustergroup_mask is not exported. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20231116142245.1233485-2-kan.liang@linux.intel.com
2023-11-04Merge tag 'x86_microcode_for_v6.7_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 microcode loading updates from Borislac Petkov: "Major microcode loader restructuring, cleanup and improvements by Thomas Gleixner: - Restructure the code needed for it and add a temporary initrd mapping on 32-bit so that the loader can access the microcode blobs. This in itself is a preparation for the next major improvement: - Do not load microcode on 32-bit before paging has been enabled. Handling this has caused an endless stream of headaches, issues, ugly code and unnecessary hacks in the past. And there really wasn't any sensible reason to do that in the first place. So switch the 32-bit loading to happen after paging has been enabled and turn the loader code "real purrty" again - Drop mixed microcode steppings loading on Intel - there, a single patch loaded on the whole system is sufficient - Rework late loading to track which CPUs have updated microcode successfully and which haven't, act accordingly - Move late microcode loading on Intel in NMI context in order to guarantee concurrent loading on all threads - Make the late loading CPU-hotplug-safe and have the offlined threads be woken up for the purpose of the update - Add support for a minimum revision which determines whether late microcode loading is safe on a machine and the microcode does not change software visible features which the machine cannot use anyway since feature detection has happened already. Roughly, the minimum revision is the smallest revision number which must be loaded currently on the system so that late updates can be allowed - Other nice leanups, fixess, etc all over the place" * tag 'x86_microcode_for_v6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) x86/microcode/intel: Add a minimum required revision for late loading x86/microcode: Prepare for minimal revision check x86/microcode: Handle "offline" CPUs correctly x86/apic: Provide apic_force_nmi_on_cpu() x86/microcode: Protect against instrumentation x86/microcode: Rendezvous and load in NMI x86/microcode: Replace the all-in-one rendevous handler x86/microcode: Provide new control functions x86/microcode: Add per CPU control field x86/microcode: Add per CPU result state x86/microcode: Sanitize __wait_for_cpus() x86/microcode: Clarify the late load logic x86/microcode: Handle "nosmt" correctly x86/microcode: Clean up mc_cpu_down_prep() x86/microcode: Get rid of the schedule work indirection x86/microcode: Mop up early loading leftovers x86/microcode/amd: Use cached microcode for AP load x86/microcode/amd: Cache builtin/initrd microcode early x86/microcode/amd: Cache builtin microcode too x86/microcode/amd: Use correct per CPU ucode_cpu_info ...