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2017-11-14Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 timer updates from Thomas Gleixner: "These updates are related to TSC handling: - Support platforms which have synchronized TSCs but the boot CPU has a non zero TSC_ADJUST value, which is considered a firmware bug on normal systems. This applies to HPE/SGI UV platforms where the platform firmware uses TSC_ADJUST to ensure TSC synchronization across a huge number of sockets, but due to power on timings the boot CPU cannot be guaranteed to have a zero TSC_ADJUST register value. - Fix the ordering of udelay calibration and kvmclock_init() - Cleanup the udelay and calibration code" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tsc: Mark cyc2ns_init() and detect_art() __init x86/platform/UV: Mark tsc_check_sync as an init function x86/tsc: Make CONFIG_X86_TSC=n build work again x86/platform/UV: Add check of TSC state set by UV BIOS x86/tsc: Provide a means to disable TSC ART x86/tsc: Drastically reduce the number of firmware bug warnings x86/tsc: Skip TSC test and error messages if already unstable x86/tsc: Add option that TSC on Socket 0 being non-zero is valid x86/timers: Move simple_udelay_calibration() past kvmclock_init() x86/timers: Make recalibrate_cpu_khz() void x86/timers: Move the simple udelay calibration to tsc.h
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
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>
2017-09-25x86/timers: Make recalibrate_cpu_khz() voidDou Liyang1-1/+1
recalibrate_cpu_khz() is called from powernow K7 and Pentium 4/Xeon CPU freq driver. It recalibrates cpu frequency in case of SMP = n and doesn't need to return anything. Mark it void, also remove the #else branch. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1500003247-17368-2-git-send-email-douly.fnst@cn.fujitsu.com
2017-05-15x86/tsc: Remodel cyc2ns to use seqcount_latch()Peter Zijlstra1-5/+3
Replace the custom multi-value scheme with the more regular seqcount_latch() scheme. Along with scrapping a lot of lines, the latch scheme is better documented and used in more places. The immediate benefit however is not being limited on the update side. The current code has a limit where the writers block which is hit by future changes. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-23sched/clock, x86/perf: Fix "perf test tsc"Peter Zijlstra1-0/+2
People reported that commit: 5680d8094ffa ("sched/clock: Provide better clock continuity") broke "perf test tsc". That commit added another offset to the reported clock value; so take that into account when computing the provided offset values. Reported-by: Adrian Hunter <adrian.hunter@intel.com> Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 5680d8094ffa ("sched/clock: Provide better clock continuity") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-21Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, cpu, amd: Fix a shadowed variable situation um, x86: Fix vDSO build x86: Delete non-required instances of include <linux/init.h> x86, realmode: Pointer walk cleanups, pull out invariant use of __pa() x86/traps: Clean up error exception handler definitions
2014-01-13sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQsPeter Zijlstra1-2/+21
Use a ring-buffer like multi-version object structure which allows always having a coherent object; we use this to avoid having to disable IRQs while reading sched_clock() and avoids a problem when getting an NMI while changing the cyc2ns data. MAINLINE PRE POST sched_clock_stable: 1 1 1 (cold) sched_clock: 329841 331312 257223 (cold) local_clock: 301773 310296 309889 (warm) sched_clock: 38375 38247 25280 (warm) local_clock: 100371 102713 85268 (warm) rdtsc: 27340 27289 24247 sched_clock_stable: 0 0 0 (cold) sched_clock: 382634 372706 301224 (cold) local_clock: 396890 399275 399870 (warm) sched_clock: 38194 38124 25630 (warm) local_clock: 143452 148698 129629 (warm) rdtsc: 27345 27365 24307 Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-s567in1e5ekq2nlyhn8f987r@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/clock, x86: Move some cyc2ns() code aroundPeter Zijlstra1-59/+0
There are no __cycles_2_ns() users outside of arch/x86/kernel/tsc.c, so move it there. There are no cycles_2_ns() users. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-01lslnavfgo3kmbo4532zlcj@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/clock, x86: Use mul_u64_u32_shr() for native_sched_clock()Peter Zijlstra1-4/+3
Use mul_u64_u32_shr() so that x86_64 can use a single 64x64->128 mul. Before: 0000000000000560 <native_sched_clock>: 560: 44 8b 1d 00 00 00 00 mov 0x0(%rip),%r11d # 567 <native_sched_clock+0x7> 567: 55 push %rbp 568: 48 89 e5 mov %rsp,%rbp 56b: 45 85 db test %r11d,%r11d 56e: 75 4f jne 5bf <native_sched_clock+0x5f> 570: 0f 31 rdtsc 572: 89 c0 mov %eax,%eax 574: 48 c1 e2 20 shl $0x20,%rdx 578: 48 c7 c1 00 00 00 00 mov $0x0,%rcx 57f: 48 09 c2 or %rax,%rdx 582: 48 c7 c7 00 00 00 00 mov $0x0,%rdi 589: 65 8b 04 25 00 00 00 mov %gs:0x0,%eax 590: 00 591: 48 98 cltq 593: 48 8b 34 c5 00 00 00 mov 0x0(,%rax,8),%rsi 59a: 00 59b: 48 89 d0 mov %rdx,%rax 59e: 81 e2 ff 03 00 00 and $0x3ff,%edx 5a4: 48 c1 e8 0a shr $0xa,%rax 5a8: 48 0f af 14 0e imul (%rsi,%rcx,1),%rdx 5ad: 48 0f af 04 0e imul (%rsi,%rcx,1),%rax 5b2: 5d pop %rbp 5b3: 48 03 04 3e add (%rsi,%rdi,1),%rax 5b7: 48 c1 ea 0a shr $0xa,%rdx 5bb: 48 01 d0 add %rdx,%rax 5be: c3 retq After: 0000000000000550 <native_sched_clock>: 550: 8b 3d 00 00 00 00 mov 0x0(%rip),%edi # 556 <native_sched_clock+0x6> 556: 55 push %rbp 557: 48 89 e5 mov %rsp,%rbp 55a: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp 55e: 85 ff test %edi,%edi 560: 75 2c jne 58e <native_sched_clock+0x3e> 562: 0f 31 rdtsc 564: 89 c0 mov %eax,%eax 566: 48 c1 e2 20 shl $0x20,%rdx 56a: 48 09 c2 or %rax,%rdx 56d: 65 48 8b 04 25 00 00 mov %gs:0x0,%rax 574: 00 00 576: 89 c0 mov %eax,%eax 578: 48 f7 e2 mul %rdx 57b: 65 48 8b 0c 25 00 00 mov %gs:0x0,%rcx 582: 00 00 584: c9 leaveq 585: 48 0f ac d0 0a shrd $0xa,%rdx,%rax 58a: 48 01 c8 add %rcx,%rax 58d: c3 retq MAINLINE POST sched_clock_stable: 1 1 (cold) sched_clock: 329841 331312 (cold) local_clock: 301773 310296 (warm) sched_clock: 38375 38247 (warm) local_clock: 100371 102713 (warm) rdtsc: 27340 27289 sched_clock_stable: 0 0 (cold) sched_clock: 382634 372706 (cold) local_clock: 396890 399275 (warm) sched_clock: 38194 38124 (warm) local_clock: 143452 148698 (warm) rdtsc: 27345 27365 Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-piu203ses5y1g36bnyw2n16x@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-07x86: Delete non-required instances of include <linux/init.h>Paul Gortmaker1-1/+0
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. [ hpa: undid incorrect removal from arch/x86/kernel/head_32.S ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Link: http://lkml.kernel.org/r/1389054026-12947-1-git-send-email-paul.gortmaker@windriver.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-03-13sched/x86: Fix overflow in cyc2ns_offsetSalman Qazi1-6/+2
When a machine boots up, the TSC generally gets reset. However, when kexec is used to boot into a kernel, the TSC value would be carried over from the previous kernel. The computation of cycns_offset in set_cyc2ns_scale is prone to an overflow, if the machine has been up more than 208 days prior to the kexec. The overflow happens when we multiply *scale, even though there is enough room to store the final answer. We fix this issue by decomposing tsc_now into the quotient and remainder of division by CYC2NS_SCALE_FACTOR and then performing the multiplication separately on the two components. Refactor code to share the calculation with the previous fix in __cycles_2_ns(). Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Turner <pjt@google.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20120310004027.19291.88460.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched, x86: Avoid unnecessary overflow in sched_clockSalman Qazi1-1/+22
(Added the missing signed-off-by line) In hundreds of days, the __cycles_2_ns calculation in sched_clock has an overflow. cyc * per_cpu(cyc2ns, cpu) exceeds 64 bits, causing the final value to become zero. We can solve this without losing any precision. We can decompose TSC into quotient and remainder of division by the scale factor, and then use this to convert TSC into nanoseconds. Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: John Stultz <johnstul@us.ibm.com> Reviewed-by: Paul Turner <pjt@google.com> Cc: stable@kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111115221121.7262.88871.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18x86, nmi_watchdog: Remove all stub function calls from old nmi_watchdogDon Zickus1-6/+0
Now that the bulk of the old nmi_watchdog is gone, remove all the stub variables and hooks associated with it. This touches lots of files mainly because of how the io_apic nmi_watchdog was implemented. Now that the io_apic nmi_watchdog is forever gone, remove all its fingers. Most of this code was not being exercised by virtue of nmi_watchdog != NMI_IO_APIC, so there shouldn't be anything to risky here. Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: fweisbec@gmail.com Cc: gorcunov@openvz.org LKML-Reference: <1289578944-28564-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-31x86: Move tsc_calibration to x86_init_opsThomas Gleixner1-5/+0
TSC calibration is modified by the vmware hypervisor and paravirt by separate means. Moorestown wants to add its own calibration routine as well. So make calibrate_tsc a proper x86_init_ops function and override it by paravirt or by the early setup of the vmware hypervisor. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-31x86: Simplify timer_ack magic in time_32.cThomas Gleixner1-2/+4
Let the compiler optimize the timer_ack magic away in the 32bit timer interrupt and put the same code into time_64.c. It's optimized out for CONFIG_X86_IO_APIC on 32bit and for 64bit because timer_ack is const 0 in both cases. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-31x86: Add timer_init to x86_init_opsThomas Gleixner1-2/+1
The timer init code is convoluted with several quirks and the paravirt timer chooser. Figuring out which code path is actually taken is not for the faint hearted. Move the numaq TSC quirk to tsc_pre_init x86_init_ops function and replace the paravirt time chooser and the remaining x86 quirk with a simple x86_init_ops function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-06-17sched, x86: Fix cpufreq + sched_clock() TSC scalingPeter Zijlstra1-1/+5
For freqency dependent TSCs we only scale the cycles, we do not account for the discrepancy in absolute value. Our current formula is: time = cycles * mult (where mult is a function of the cpu-speed on variable tsc machines) Suppose our current cycle count is 10, and we have a multiplier of 5, then our time value would end up being 50. Now cpufreq comes along and changes the multiplier to say 3 or 7, which would result in our time being resp. 30 or 70. That means that we can observe random jumps in the time value due to frequency changes in both fwd and bwd direction. So what this patch does is change the formula to: time = cycles * frequency + offset And we calculate offset so that time_before == time_after, thereby ridding us of these jumps in time. [ Impact: fix/reduce sched_clock() jumps across frequency changing events ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> Chucked-on-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2009-03-30x86: fix mismerge in arch/x86/include/asm/timer.hStephen Rothwell1-1/+1
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-23x86: refactor x86_quirks supportIngo Molnar1-0/+2
Impact: cleanup Make x86_quirks support more transparent. The highlevel methods are now named: extern void x86_quirk_pre_intr_init(void); extern void x86_quirk_intr_init(void); extern void x86_quirk_trap_init(void); extern void x86_quirk_pre_time_init(void); extern void x86_quirk_time_init(void); This makes it clear that if some platform extension has to do something here that it is considered ... weird, and is discouraged. Also remove arch_hooks.h and move it into setup.h (and other header files where appropriate). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-23x86: Fix ASM_X86__ header guardsH. Peter Anvin1-3/+3
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since: a. the double underscore is ugly and pointless. b. no leading underscore violates namespace constraints. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-23x86, um: ... and asm-x86 moveAl Viro1-0/+66
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>