kernel.git/arch/x86/kernel/tsc.c, branch linux-5.9.y

x86/tsc: Add tsc_early_khz command line parameter

2020-05-21T21:07:00Z

Changing base clock frequency directly impacts TSC Hz but not CPUID.16h value. An overclocked CPU supporting CPUID.16h and with partial CPUID.15h support will set TSC KHZ according to "best guess" given by CPUID.16h relying on tsc_refine_calibration_work to give better numbers later. tsc_refine_calibration_work will refuse to do its work when the outcome is off the early TSC KHZ value by more than 1% which is certain to happen on an overclocked system. Fix this by adding a tsc_early_khz command line parameter that makes the kernel skip early TSC calibration and use the given value instead. This allows the user to provide the expected TSC frequency that is closer to reality than the one reported by the hardware, enabling tsc_refine_calibration_work to do meaningful error checking. [ tglx: Made the variable __initdata as it's only used on init and removed the error checking in the argument parser because kstrto*() only stores to the variable if the string is valid ] Signed-off-by: Krzysztof Piecuch Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/O2CpIOrqLZHgNRkfjRpz_LGqnc1ix_seNIiOCvHY4RHoulOVRo6kMXKuLOfBVTi0SMMevg6Go1uZ_cL9fLYtYdTRNH78ChaFaZyG3VAyYz8=@protonmail.com

Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-03-31T18:04:05Z

Pull x86 cleanups from Ingo Molnar: "This topic tree contains more commits than usual: - most of it are uaccess cleanups/reorganization by Al - there's a bunch of prototype declaration (--Wmissing-prototypes) cleanups - misc other cleanups all around the map" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/mm/set_memory: Fix -Wmissing-prototypes warnings x86/efi: Add a prototype for efi_arch_mem_reserve() x86/mm: Mark setup_emu2phys_nid() static x86/jump_label: Move 'inline' keyword placement x86/platform/uv: Add a missing prototype for uv_bau_message_interrupt() kill uaccess_try() x86: unsafe_put-style macro for sigmask x86: x32_setup_rt_frame(): consolidate uaccess areas x86: __setup_rt_frame(): consolidate uaccess areas x86: __setup_frame(): consolidate uaccess areas x86: setup_sigcontext(): list user_access_{begin,end}() into callers x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit) x86: ia32_setup_rt_frame(): consolidate uaccess areas x86: ia32_setup_frame(): consolidate uaccess areas x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers x86/alternatives: Mark text_poke_loc_init() static x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl() x86/mm: Drop pud_mknotpresent() x86: Replace setup_irq() by request_irq() x86/configs: Slightly reduce defconfigs ...

x86/vdso: Use generic VDSO clock mode storage

2020-02-17T13:40:23Z

Switch to the generic VDSO clock mode storage. Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino (VDSO parts) Acked-by: Juergen Gross (Xen parts) Acked-by: Paolo Bonzini (KVM parts) Link: https://lkml.kernel.org/r/20200207124403.152039903@linutronix.de

x86/vdso: Move VDSO clocksource state tracking to callback

2020-02-17T13:40:22Z

All architectures which use the generic VDSO code have their own storage for the VDSO clock mode. That's pointless and just requires duplicate code. X86 abuses the function which retrieves the architecture specific clock mode storage to mark the clocksource as used in the VDSO. That's silly because this is invoked on every tick when the VDSO data is updated. Move this functionality to the clocksource::enable() callback so it gets invoked once when the clocksource is installed. This allows to make the clock mode storage generic. Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley (Hyper-V parts) Reviewed-by: Vincenzo Frascino (VDSO parts) Acked-by: Juergen Gross (Xen parts) Link: https://lkml.kernel.org/r/20200207124402.934519777@linutronix.de

x86: Fix a handful of typos

2020-02-16T19:58:06Z

Fix a couple of typos in code comments. [ bp: While at it: s/IRQ's/IRQs/. ] Signed-off-by: Martin Molnar Signed-off-by: Borislav Petkov Reviewed-by: Randy Dunlap Link: https://lkml.kernel.org/r/0819a044-c360-44a4-f0b6-3f5bafe2d35c@gmail.com

x86/tsc: Respect tsc command line paraemeter for clocksource_tsc_early

2019-11-05T00:24:56Z

The introduction of clocksource_tsc_early broke the functionality of "tsc=reliable" and "tsc=nowatchdog" command line parameters, since clocksource_tsc_early is unconditionally registered with CLOCK_SOURCE_MUST_VERIFY and thus put on the watchdog list. This can cause the TSC to be declared unstable during boot: clocksource: timekeeping watchdog on CPU0: Marking clocksource 'tsc-early' as unstable because the skew is too large: clocksource: 'refined-jiffies' wd_now: fffb7018 wd_last: fffb6e9d mask: ffffffff clocksource: 'tsc-early' cs_now: 68a6a7070f6a0 cs_last: 68a69ab6f74d6 mask: ffffffffffffffff tsc: Marking TSC unstable due to clocksource watchdog The corresponding elapsed times are cs_nsec=1224152026 and wd_nsec=378942392, so the watchdog differs from TSC by 0.84 seconds. This happens when HPET is not available and jiffies are used as the TSC watchdog instead and the jiffies update is not happening due to lost timer interrupts in periodic mode, which can happen e.g. with expensive debug mechanisms enabled or under massive overload conditions in virtualized environments. Before the introduction of the early TSC clocksource the command line parameters "tsc=reliable" and "tsc=nowatchdog" could be used to work around this issue. Restore the behaviour by disabling the watchdog if requested on the kernel command line. [ tglx: Clarify changelog ] Fixes: aa83c45762a24 ("x86/tsc: Introduce early tsc clocksource") Signed-off-by: Michael Zhivich Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20191024175945.14338-1-mzhivich@akamai.com

x86/intel: Aggregate microserver naming

2019-08-28T09:29:32Z

Currently big microservers have _XEON_D while small microservers have _X, Make it uniformly: _D. for i in `git grep -l "$INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6$.*_$X\|XEON_D$"` do sed -i -e 's/$\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6$.*ATOM.*\)_X/\1_D/g' \ -e 's/$\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6$.*\)_XEON_D/\1_D/g' ${i} done Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Tony Luck Cc: x86@kernel.org Cc: Dave Hansen Cc: Thomas Gleixner Cc: Borislav Petkov Link: https://lkml.kernel.org/r/20190827195122.677152989@infradead.org

Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-07-09T00:27:24Z

Pull x86 cleanups from Ingo Molnar: "Misc small cleanups: removal of superfluous code and coding style cleanups mostly" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kexec: Make variable static and config dependent x86/defconfigs: Remove useless UEVENT_HELPER_PATH x86/amd_nb: Make hygon_nb_misc_ids static x86/tsc: Move inline keyword to the beginning of function declarations x86/io_delay: Define IO_DELAY macros in C instead of Kconfig x86/io_delay: Break instead of fallthrough in switch statement

Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-07-08T18:22:57Z

Pull x96 apic updates from Thomas Gleixner: "Updates for the x86 APIC interrupt handling and APIC timer: - Fix a long standing issue with spurious interrupts which was caused by the big vector management rework a few years ago. Robert Hodaszi provided finally enough debug data and an excellent initial failure analysis which allowed to understand the underlying issues. This contains a change to the core interrupt management code which is required to handle this correctly for the APIC/IO_APIC. The core changes are NOOPs for most architectures except ARM64. ARM64 is not impacted by the change as confirmed by Marc Zyngier. - Newer systems allow to disable the PIT clock for power saving causing panic in the timer interrupt delivery check of the IO/APIC when the HPET timer is not enabled either. While the clock could be turned on this would cause an endless whack a mole game to chase the proper register in each affected chipset. These systems provide the relevant frequencies for TSC, CPU and the local APIC timer via CPUID and/or MSRs, which allows to avoid the PIT/HPET based calibration. As the calibration code is the only usage of the legacy timers on modern systems and is skipped anyway when the frequencies are known already, there is no point in setting up the PIT and actually checking for the interrupt delivery via IO/APIC. To achieve this on a wide variety of platforms, the CPUID/MSR based frequency readout has been made more robust, which also allowed to remove quite some workarounds which turned out to be not longer required. Thanks to Daniel Drake for analysis, patches and verification" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Seperate unused system vectors from spurious entry again x86/irq: Handle spurious interrupt after shutdown gracefully x86/ioapic: Implement irq_get_irqchip_state() callback genirq: Add optional hardware synchronization for shutdown genirq: Fix misleading synchronize_irq() documentation genirq: Delay deactivation in free_irq() x86/timer: Skip PIT initialization on modern chipsets x86/apic: Use non-atomic operations when possible x86/apic: Make apic_bsp_setup() static x86/tsc: Set LAPIC timer period to crystal clock frequency x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period' x86/tsc: Use CPUID.0x16 to calculate missing crystal frequency

x86/tsc: Move inline keyword to the beginning of function declarations

2019-06-14T15:02:09Z

The inline keyword was not at the beginning of the function declarations. Fix the following warnings triggered when using W=1: arch/x86/kernel/tsc.c:62:1: warning: 'inline' is not at beginning of declaration [-Wold-style-declaration] arch/x86/kernel/tsc.c:79:1: warning: 'inline' is not at beginning of declaration [-Wold-style-declaration] Signed-off-by: Mathieu Malaterre Signed-off-by: Thomas Gleixner Cc: trivial@kernel.org Cc: kernel-janitors@vger.kernel.org Cc: Peter Zijlstra Cc: Borislav Petkov Cc: "H. Peter Anvin" Link: https://lkml.kernel.org/r/20190524103252.28575-1-malat@debian.org