kernel.git/arch/x86/Makefile, branch linux-4.12.y

x86/build: Permit building with old make versions

2017-05-24T07:05:17Z

At least Make 3.82 dislikes the tab in front of the $(warning) function: arch/x86/Makefile:162: *** recipe commences before first target. Stop. Let's be gentle. Signed-off-by: Jan Kiszka Acked-by: Thomas Gleixner Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1944fcd8-e3df-d1f7-c0e4-60aeb1917a24@siemens.com Signed-off-by: Ingo Molnar

x86/build: Don't add -maccumulate-outgoing-args w/o compiler support

2017-05-09T06:16:45Z

Clang does not support this machine dependent option. Older versions of GCC (pre 3.0) may not support this option, added in 2000, but it's unlikely they can still compile a working kernel. Signed-off-by: Nick Desaulniers Reviewed-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170509032946.20444-1-nick.desaulniers@gmail.com Signed-off-by: Ingo Molnar

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

2017-05-02T05:33:43Z

Pull x86 build update from Ingo Molnar: "A single CLang support related fix" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kbuild: Use cc-option to enable -falign-{jumps/loops}

x86/build: convert function graph '-Os' error to warning

2017-04-19T07:57:23Z

For pre-4.6.0 versions of GCC, which don't have '-mfentry', the '-maccumulate-outgoing-args' option is required for function graph tracing in order to avoid GCC bug 42109. However, GCC ignores '-maccumulate-outgoing-args' when '-Os' is also set. Currently we force a build error to prevent that scenario, but that breaks randconfigs. So change the error to a warning which also disables CONFIG_CC_OPTIMIZE_FOR_SIZE. Reported-by: Andi Kleen Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: kbuild test robot Cc: kbuild-all@01.org Link: http://lkml.kernel.org/r/20170418214429.o7fbwbmf4nqosezy@treble Signed-off-by: Ingo Molnar

x86/kbuild: Use cc-option to enable -falign-{jumps/loops}

2017-04-17T10:39:37Z

clang currently does not support these optimizations, only enable them when they are available. Signed-off-by: Matthias Kaehlcke Cc: Greg Hackmann Cc: Linus Torvalds Cc: Masahiro Yamada Cc: Michael Davidson Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: grundler@chromium.org Link: http://lkml.kernel.org/r/20170413172609.118122-1-mka@chromium.org Signed-off-by: Ingo Molnar

x86/build: Mostly disable '-maccumulate-outgoing-args'

2017-03-30T09:53:04Z

The GCC '-maccumulate-outgoing-args' flag is enabled for most configs, mostly because of issues which are no longer relevant. For most configs, and with most recent versions of GCC, it's no longer needed. Clarify which cases need it, and only enable it for those cases. Also produce a compile-time error for the ftrace graph + mcount + '-Os' case, which will otherwise cause runtime failures. The main benefit of '-maccumulate-outgoing-args' is that it prevents an ugly prologue for functions which have aligned stacks. But removing the option also has some benefits: more readable argument saves, smaller text size, and (presumably) slightly improved performance. Here are the object size savings for 32-bit and 64-bit defconfig kernels: text data bss dec hex filename 10006710 3543328 1773568 15323606 e9d1d6 vmlinux.x86-32.before 9706358 3547424 1773568 15027350 e54c96 vmlinux.x86-32.after text data bss dec hex filename 10652105 4537576 843776 16033457 f4a6b1 vmlinux.x86-64.before 10639629 4537576 843776 16020981 f475f5 vmlinux.x86-64.after That comes out to a 3% text size improvement on x86-32 and a 0.1% text size improvement on x86-64. Signed-off-by: Josh Poimboeuf Cc: Andrew Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble Signed-off-by: Ingo Molnar

lib/raid6: Add AVX512 optimized gen_syndrome functions

2016-09-21T16:09:44Z

Optimize RAID6 gen_syndrom functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized gen_syndrom functions, which is simply based on avx2.c written by Yuanhan Liu and sse2.c written by hpa. The patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: H. Peter Anvin Cc: Jim Kukunas Cc: Fenghua Yu Signed-off-by: Megha Dey Signed-off-by: Gayatri Kammela Reviewed-by: Fenghua Yu Signed-off-by: Shaohua Li

kbuild: abort build on bad stack protector flag

2016-07-26T23:19:19Z

Before, the stack protector flag was sanity checked before .config had been reprocessed. This meant the build couldn't be aborted early, and only a warning could be emitted followed later by the compiler blowing up with an unknown flag. This has caused a lot of confusion over time, so this splits the flag selection from sanity checking and performs the sanity checking after the make has been restarted from a reprocessed .config, so builds can be aborted as early as possible now. Additionally moves the x86-specific sanity check to the same location, since it suffered from the same warn-then-wait-for-compiler-failure problem. Link: http://lkml.kernel.org/r/20160712223043.GA11664@www.outflux.net Signed-off-by: Kees Cook Cc: Michal Marek Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86/init: Rename EBDA code file

2016-04-22T08:29:07Z

This makes it clearer what this is. Signed-off-by: Luis R. Rodriguez Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jgross@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-14-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar

x86/rtc: Replace paravirt rtc check with platform legacy quirk

2016-04-22T08:29:01Z

We have 4 types of x86 platforms that disable RTC: * Intel MID * Lguest - uses paravirt * Xen dom-U - uses paravirt * x86 on legacy systems annotated with an ACPI legacy flag We can consolidate all of these into a platform specific legacy quirk set early in boot through i386_start_kernel() and through x86_64_start_reservations(). This deals with the RTC quirks which we can rely on through the hardware subarch, the ACPI check can be dealt with separately. For Xen things are bit more complex given that the @X86_SUBARCH_XEN x86_hardware_subarch is shared on for Xen which uses the PV path for both domU and dom0. Since the semantics for differentiating between the two are Xen specific we provide a platform helper to help override default legacy features -- x86_platform.set_legacy_features(). Use of this helper is highly discouraged, its only purpose should be to account for the lack of semantics available within your given x86_hardware_subarch. As per 0-day, this bumps the vmlinux size using i386-tinyconfig as follows: TOTAL TEXT init.text x86_early_init_platform_quirks() +70 +62 +62 +43 Only 8 bytes overhead total, as the main increase in size is all removed via __init. Suggested-by: Ingo Molnar Signed-off-by: Luis R. Rodriguez Reviewed-by: Juergen Gross Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-5-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar