kernel.git/arch/x86/kernel/tsc.c, branch linux-4.14.y

x86/cpu: Sanitize FAM6_ATOM naming

2019-05-14T17:18:42Z

commit f2c4db1bd80720cd8cb2a5aa220d9bc9f374f04e upstream Going primarily by: https://en.wikipedia.org/wiki/List_of_Intel_Atom_microprocessors with additional information gleaned from other related pages; notably: - Bonnell shrink was called Saltwell - Moorefield is the Merriefield refresh which makes it Airmont The general naming scheme is: FAM6_ATOM_UARCH_SOCTYPE for i in `git grep -l FAM6_ATOM` ; do sed -i -e 's/ATOM_PINEVIEW/ATOM_BONNELL/g' \ -e 's/ATOM_LINCROFT/ATOM_BONNELL_MID/' \ -e 's/ATOM_PENWELL/ATOM_SALTWELL_MID/g' \ -e 's/ATOM_CLOVERVIEW/ATOM_SALTWELL_TABLET/g' \ -e 's/ATOM_CEDARVIEW/ATOM_SALTWELL/g' \ -e 's/ATOM_SILVERMONT1/ATOM_SILVERMONT/g' \ -e 's/ATOM_SILVERMONT2/ATOM_SILVERMONT_X/g' \ -e 's/ATOM_MERRIFIELD/ATOM_SILVERMONT_MID/g' \ -e 's/ATOM_MOOREFIELD/ATOM_AIRMONT_MID/g' \ -e 's/ATOM_DENVERTON/ATOM_GOLDMONT_X/g' \ -e 's/ATOM_GEMINI_LAKE/ATOM_GOLDMONT_PLUS/g' ${i} done Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: dave.hansen@linux.intel.com Cc: len.brown@intel.com Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

x86/tsc: Force inlining of cyc2ns bits

2018-11-10T15:48:36Z

commit 4907c68abd3f60f650f98d5a69d4ec77c0bde44f upstream. Looking at the asm for native_sched_clock() I noticed we don't inline enough. Mostly caused by sharing code with cyc2ns_read_begin(), which we didn't used to do. So mark all that __force_inline to make it DTRT. Fixes: 59eaef78bfea ("x86/tsc: Remodel cyc2ns to use seqcount_latch()") Reported-by: Eric Dumazet Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Cc: hpa@zytor.com Cc: eric.dumazet@gmail.com Cc: bp@alien8.de Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181011104019.695196158@infradead.org Signed-off-by: Greg Kroah-Hartman

x86/tsc: Allow TSC calibration without PIT

2018-04-26T09:02:03Z

[ Upstream commit 30c7e5b123673d5e570e238dbada2fb68a87212c ] Zhang Rui reported that a Surface Pro 4 will fail to boot with lapic=notscdeadline. Part of the problem is that that machine doesn't have a PIT. If, for some reason, the TSC init has to fall back to TSC calibration, it relies on the PIT to be present. Allow TSC calibration to reliably fall back to HPET. The below results in an accurate TSC measurement when forced on a IVB: tsc: Unable to calibrate against PIT tsc: No reference (HPET/PMTIMER) available tsc: Unable to calibrate against PIT tsc: using HPET reference calibration tsc: Detected 2792.451 MHz processor Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Cc: len.brown@intel.com Cc: rui.zhang@intel.com Link: https://lkml.kernel.org/r/20171222092243.333145937@infradead.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86/tsc: Prevent 32bit truncation in calc_hpet_ref()

2018-04-26T09:02:02Z

commit d3878e164dcd3925a237a20e879432400e369172 upstream. The TSC calibration code uses HPET as reference. The conversion normalizes the delta of two HPET timestamps: hpetref = ((tshpet1 - tshpet2) * HPET_PERIOD) / 1e6 and then divides the normalized delta of the corresponding TSC timestamps by the result to calulate the TSC frequency. tscfreq = ((tstsc1 - tstsc2 ) * 1e6) / hpetref This uses do_div() which takes an u32 as the divisor, which worked so far because the HPET frequency was low enough that 'hpetref' never exceeded 32bit. On Skylake machines the HPET frequency increased so 'hpetref' can exceed 32bit. do_div() truncates the divisor, which causes the calibration to fail. Use div64_u64() to avoid the problem. [ tglx: Fixes whitespace mangled patch and rewrote changelog ] Signed-off-by: Xiaoming Gao Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Cc: peterz@infradead.org Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/38894564-4fc9-b8ec-353f-de702839e44e@gmail.com Signed-off-by: Greg Kroah-Hartman

x86/tsc: Fix erroneous TSC rate on Skylake Xeon

2018-01-23T18:58:14Z

commit b511203093489eb1829cb4de86e8214752205ac6 upstream. The INTEL_FAM6_SKYLAKE_X hardcoded crystal_khz value of 25MHZ is problematic: - SKX workstations (with same model # as server variants) use a 24 MHz crystal. This results in a -4.0% time drift rate on SKX workstations. - SKX servers subject the crystal to an EMI reduction circuit that reduces its actual frequency by (approximately) -0.25%. This results in -1 second per 10 minute time drift as compared to network time. This issue can also trigger a timer and power problem, on configurations that use the LAPIC timer (versus the TSC deadline timer). Clock ticks scheduled with the LAPIC timer arrive a few usec before the time they are expected (according to the slow TSC). This causes Linux to poll-idle, when it should be in an idle power saving state. The idle and clock code do not graciously recover from this error, sometimes resulting in significant polling and measurable power impact. Stop using native_calibrate_tsc() for INTEL_FAM6_SKYLAKE_X. native_calibrate_tsc() will return 0, boot will run with tsc_khz = cpu_khz, and the TSC refined calibration will update tsc_khz to correct for the difference. [ tglx: Sanitized change log ] Fixes: 6baf3d61821f ("x86/tsc: Add additional Intel CPU models to the crystal quirk list") Signed-off-by: Len Brown Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Cc: Prarit Bhargava Link: https://lkml.kernel.org/r/ff6dcea166e8ff8f2f6a03c17beab2cb436aa779.1513920414.git.len.brown@intel.com Signed-off-by: Greg Kroah-Hartman

x86/tsc: Future-proof native_calibrate_tsc()

2018-01-23T18:58:14Z

commit da4ae6c4a0b8dee5a5377a385545d2250fa8cddb upstream. If the crystal frequency cannot be determined via CPUID(15).crystal_khz or the built-in table then native_calibrate_tsc() will still set the X86_FEATURE_TSC_KNOWN_FREQ flag which prevents the refined TSC calibration. As a consequence such systems use cpu_khz for the TSC frequency which is incorrect when cpu_khz != tsc_khz resulting in time drift. Return early when the crystal frequency cannot be retrieved without setting the X86_FEATURE_TSC_KNOWN_FREQ flag. This ensures that the refined TSC calibration is invoked. [ tglx: Steam-blastered changelog. Sigh ] Fixes: 4ca4df0b7eb0 ("x86/tsc: Mark TSC frequency determined by CPUID as known") Signed-off-by: Len Brown Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Cc: Bin Gao Link: https://lkml.kernel.org/r/0fe2503aa7d7fc69137141fc705541a78101d2b9.1513920414.git.len.brown@intel.com Signed-off-by: Greg Kroah-Hartman

x86/smpboot: Make optimization of delay calibration work correctly

2017-11-07T15:04:54Z

If the TSC has constant frequency then the delay calibration can be skipped when it has been calibrated for a package already. This is checked in calibrate_delay_is_known(), but that function is buggy in two aspects: It returns 'false' if (!tsc_disabled && !cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC) which is obviously the reverse of the intended check and the check for the sibling mask cannot work either because the topology links have not been set up yet. Correct the condition and move the call to set_cpu_sibling_map() before invoking calibrate_delay() so the sibling check works correctly. [ tglx: Rewrote changelong ] Fixes: c25323c07345 ("x86/tsc: Use topology functions") Signed-off-by: Pavel Tatashin Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Cc: bob.picco@oracle.com Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20171028001100.26603-1-pasha.tatashin@oracle.com

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

2017-07-04T01:01:50Z

Pull x86 timers updates from Thomas Gleixner: "This update contains: - The solution for the TSC deadline timer borkage, which is caused by a hardware problem in the TSC_ADJUST/TSC_DEADLINE_TIMER logic. The problem is documented now and fixed with a microcode update, so we can remove the workaround and just check for the microcode version. If the microcode is not up to date, then the TSC deadline timer is disabled. If the borkage is fixed by the proper microcode version, then the deadline timer can be used. In both cases the restrictions to the range of the TSC_ADJUST value, which were added as workarounds, are removed. - A few simple fixes and updates to the timer related x86 code" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tsc: Call check_system_tsc_reliable() before unsynchronized_tsc() x86/hpet: Do not use smp_processor_id() in preemptible code x86/time: Make setup_default_timer_irq() static x86/tsc: Remove the TSC_ADJUST clamp x86/apic: Add TSC_DEADLINE quirk due to errata x86/apic: Change the lapic name in deadline mode

x86/tsc: Call check_system_tsc_reliable() before unsynchronized_tsc()

2017-06-22T14:00:03Z

tsc_clocksource_reliable is initialized in check_system_tsc_reliable(), but it is checked in unsynchronized_tsc() which is called before the initialization. In practice that's not an issue because systems which mark the TSC reliable have X86_FEATURE_CONSTANT_TSC set as well, which is evaluated in unsynchronized_tsc() before tsc_clocksource_reliable. Reorder the calls so initialization happens before usage. [ tglx: Massaged changelog ] Signed-off-by: Zhenzhong Duan Signed-off-by: Thomas Gleixner Link: http://lkml.kernel.org/r/b1532ef7-cd9f-45f7-9f49-48dd2a5c2495@default

x86/tsc: Fold set_cyc2ns_scale() into caller

2017-05-23T08:11:04Z

The newly introduced wrapper function only has one caller, and this one is conditional, causing a harmless warning when CONFIG_CPU_FREQ is disabled: arch/x86/kernel/tsc.c:189:13: error: 'set_cyc2ns_scale' defined but not used [-Werror=unused-function] My first idea was to move the wrapper inside of that #ifdef, but on second thought it seemed nicer to remove it completely again and rename __set_cyc2ns_scale back to set_cyc2ns_scale, but leaving the extra argument. Signed-off-by: Arnd Bergmann Acked-by: Peter Zijlstra Cc: Linus Torvalds Cc: Prarit Bhargava Cc: Thomas Gleixner Fixes: 615cd03373a0 ("x86/tsc: Fix sched_clock() sync") Link: http://lkml.kernel.org/r/20170517203949.2052220-1-arnd@arndb.de Signed-off-by: Ingo Molnar