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2016-05-28Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull more MIPS updates from Ralf Baechle: "This is the secondnd batch of MIPS patches for 4.7. Summary: CPS: - Copy EVA configuration when starting secondary VPs. EIC: - Clear Status IPL. Lasat: - Fix a few off by one bugs. lib: - Mark intrinsics notrace. Not only are the intrinsics uninteresting, it would cause infinite recursion. MAINTAINERS: - Add file patterns for MIPS BRCM device tree bindings. - Add file patterns for mips device tree bindings. MT7628: - Fix MT7628 pinmux typos. - wled_an pinmux gpio. - EPHY LEDs pinmux support. Pistachio: - Enable KASLR VDSO: - Build microMIPS VDSO for microMIPS kernels. - Fix aliasing warning by building with `-fno-strict-aliasing' for debugging but also tracing them might result in recursion. Misc: - Add missing FROZEN hotplug notifier transitions. - Fix clk binding example for varioius PIC32 devices. - Fix cpu interrupt controller node-names in the DT files. - Fix XPA CPU feature separation. - Fix write_gc0_* macros when writing zero. - Add inline asm encoding helpers. - Add missing VZ accessor microMIPS encodings. - Fix little endian microMIPS MSA encodings. - Add 64-bit HTW fields and fix its configuration. - Fix sigreturn via VDSO on microMIPS kernel. - Lots of typo fixes. - Add definitions of SegCtl registers and use them" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (49 commits) MIPS: Add missing FROZEN hotplug notifier transitions MIPS: Build microMIPS VDSO for microMIPS kernels MIPS: Fix sigreturn via VDSO on microMIPS kernel MIPS: devicetree: fix cpu interrupt controller node-names MIPS: VDSO: Build with `-fno-strict-aliasing' MIPS: Pistachio: Enable KASLR MIPS: lib: Mark intrinsics notrace MIPS: Fix 64-bit HTW configuration MIPS: Add 64-bit HTW fields MAINTAINERS: Add file patterns for mips device tree bindings MAINTAINERS: Add file patterns for mips brcm device tree bindings MIPS: Simplify DSP instruction encoding macros MIPS: Add missing tlbinvf/XPA microMIPS encodings MIPS: Fix little endian microMIPS MSA encodings MIPS: Add missing VZ accessor microMIPS encodings MIPS: Add inline asm encoding helpers MIPS: Spelling fix lets -> let's MIPS: VR41xx: Fix typo MIPS: oprofile: Fix typo MIPS: math-emu: Fix typo ...
2016-05-28MIPS: Add missing FROZEN hotplug notifier transitionsAnna-Maria Gleixner
The corresponding FROZEN hotplug notifier transitions used on suspend/resume are ignored. Therefore the switch case action argument is masked with the frozen hotplug notifier transition mask. Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: rt@linutronix.de Patchwork: https://patchwork.linux-mips.org/patch/13351/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Build microMIPS VDSO for microMIPS kernelsJames Hogan
MicroMIPS kernels may be expected to run on microMIPS only cores which don't support the normal MIPS instruction set, so be sure to pass the -mmicromips flag through to the VDSO cflags. Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.4.x- Patchwork: https://patchwork.linux-mips.org/patch/13349/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Fix sigreturn via VDSO on microMIPS kernelJames Hogan
In microMIPS kernels, handle_signal() sets the isa16 mode bit in the vdso address so that the sigreturn trampolines (which are offset from the VDSO) get executed as microMIPS. However commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") changed the offsets to come from the VDSO image, which already have the isa16 mode bit set correctly since they're extracted from the VDSO shared library symbol table. Drop the isa16 mode bit handling from handle_signal() to fix sigreturn for cores which support both microMIPS and normal MIPS. This doesn't fix microMIPS only cores, since the VDSO is still built for normal MIPS, but thats a separate problem. Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.4.x- Patchwork: https://patchwork.linux-mips.org/patch/13348/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: devicetree: fix cpu interrupt controller node-namesAntony Pavlov
Here is the quote from [1]: The unit-address must match the first address specified in the reg property of the node. If the node has no reg property, the @ and unit-address must be omitted and the node-name alone differentiates the node from other nodes at the same level This patch adjusts MIPS dts-files and devicetree binding documentation in accordance with [1]. [1] Power.org(tm) Standard for Embedded Power Architecture(tm) Platform Requirements (ePAPR). Version 1.1 – 08 April 2011. Chapter 2.2.1.1 Node Name Requirements Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> Cc: Kumar Gala <galak@codeaurora.org> Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13345/ Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: VDSO: Build with `-fno-strict-aliasing'Maciej W. Rozycki
Avoid an aliasing issue causing a build error in VDSO: In file included from include/linux/srcu.h:34:0, from include/linux/notifier.h:15, from ./arch/mips/include/asm/uprobes.h:9, from include/linux/uprobes.h:61, from include/linux/mm_types.h:13, from ./arch/mips/include/asm/vdso.h:14, from arch/mips/vdso/vdso.h:27, from arch/mips/vdso/gettimeofday.c:11: include/linux/workqueue.h: In function 'work_static': include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] return *work_data_bits(work) & WORK_STRUCT_STATIC; ^ cc1: all warnings being treated as errors make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1 with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0. Include `-fno-strict-aliasing' along with compiler options used, as required for kernel code, fixing a problem present since the introduction of VDSO with commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO"). Thanks to Tejun for diagnosing this properly! Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Tejun Heo <tj@kernel.org> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.3+ Patchwork: https://patchwork.linux-mips.org/patch/13357/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Pistachio: Enable KASLRMatt Redfearn
Allow KASLR to be selected on Pistachio based systems. Tested on a Creator Ci40. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Andrew Bresticker <abrestic@chromium.org> Cc: Jonas Gorski <jogo@openwrt.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13356/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: lib: Mark intrinsics notraceHarvey Hunt
On certain MIPS32 devices, the ftrace tracer "function_graph" uses __lshrdi3() during the capturing of trace data. ftrace then attempts to trace __lshrdi3() which leads to infinite recursion and a stack overflow. Fix this by marking __lshrdi3() as notrace. Mark the other compiler intrinsics as notrace in case the compiler decides to use them in the ftrace path. Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Cc: <linux-mips@linux-mips.org> Cc: <linux-kernel@vger.kernel.org> Cc: <stable@vger.kernel.org> # 4.2.x- Patchwork: https://patchwork.linux-mips.org/patch/13354/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Fix 64-bit HTW configurationJames Hogan
The Hardware page Table Walker (HTW) is being misconfigured on 64-bit kernels. The PWSize.PS (pointer size) bit determines whether pointers within directories are loaded as 32-bit or 64-bit addresses, but was never being set to 1 for 64-bit kernels where the unsigned long in pgd_t is 64-bits wide. This actually reduces rather than improves performance when the HTW is enabled on P6600 since the HTW is initiated lots, but walks are all aborted due I think to bad intermediate pointers. Since we were already taking the width of the PTEs into account by setting PWSize.PTEW, which is the left shift applied to the page table index *in addition to* the native pointer size, we also need to reduce PTEW by 1 when PS=1. This is done by calculating PTEW based on the relative size of pte_t compared to pgd_t. Finally in order for the HTW to be used when PS=1, the appropriate XK/XS/XU bits corresponding to the different 64-bit segments need to be set in PWCtl. We enable only XU for now to enable walking for XUSeg. Supporting walking for XKSeg would be a bit more involved so is left for a future patch. It would either require the use of a per-CPU top level base directory if supported by the HTW (a bit like pgd_current but with a second entry pointing at swapper_pg_dir), or the HTW would prepend bit 63 of the address to the global directory index which doesn't really match how we split user and kernel page directories. Fixes: cab25bc7537b ("MIPS: Extend hardware table walking support to MIPS64") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13364/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add 64-bit HTW fieldsJames Hogan
Add field definitions for some of the 64-bit specific Hardware page Table Walker (HTW) register fields in PWSize and PWCtl, in preparation for fixing the 64-bit HTW configuration. Also print these fields out along with the others in print_htw_config(). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13363/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Simplify DSP instruction encoding macrosJames Hogan
Simplify the DSP instruction wrapper macros which use explicit encodings for microMIPS and normal MIPS by using the new encoding macros and removing duplication. To me this makes it easier to read since it is much shorter, but it also ensures .insn is used, preventing objdump disassembling the microMIPS code as normal MIPS. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13314/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add missing tlbinvf/XPA microMIPS encodingsJames Hogan
Hardcoded MIPS instruction encodings are provided for tlbinvf, mfhc0 & mthc0 instructions, but microMIPS encodings are missing. I doubt any microMIPS cores exist at present which support these instructions, but the microMIPS encodings exist, and microMIPS cores may support them in the future. Add the missing microMIPS encodings using the new macros. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13313/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Fix little endian microMIPS MSA encodingsJames Hogan
When the toolchain doesn't support MSA we encode MSA instructions explicitly in assembly. Unfortunately we use .word for both MIPS and microMIPS encodings which is wrong, since 32-bit microMIPS instructions are made up from a pair of halfwords. - The most significant halfword always comes first, so for little endian builds the halves will be emitted in the wrong order. - 32-bit alignment isn't guaranteed, so the assembler may insert a 16-bit nop instruction to pad the instruction stream to a 32-bit boundary. Use the new instruction encoding macros to encode microMIPS MSA instructions correctly. Fixes: d96cc3d1ec5d ("MIPS: Add microMIPS MSA support.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <Paul.Burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13312/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add missing VZ accessor microMIPS encodingsJames Hogan
Toolchains may be used which support microMIPS but not VZ instructions (i.e. binutis 2.22 & 2.23), so extend the explicitly encoded versions of the guest COP0 register & guest TLB access macros to support microMIPS encodings too, using the new macros. This prevents non-microMIPS instructions being executed in microMIPS mode during CPU probe on cores supporting VZ (e.g. M5150), which cause reserved instruction exceptions early during boot. Fixes: bad50d79255a ("MIPS: Fix VZ probe gas errors with binutils <2.24") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13311/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add inline asm encoding helpersJames Hogan
To allow simplification of macros which use inline assembly to explicitly encode instructions, add a few simple abstractions to mipsregs.h which expand to specific microMIPS or normal MIPS encodings depending on what type of kernel is being built: _ASM_INSN_IF_MIPS(_enc) : Emit a 32bit MIPS instruction if microMIPS is not enabled. _ASM_INSN32_IF_MM(_enc) : Emit a 32bit microMIPS instruction if enabled. _ASM_INSN16_IF_MM(_enc) : Emit a 16bit microMIPS instruction if enabled. The macros can be used one after another since the MIPS / microMIPS macros are mutually exclusive, for example: __asm__ __volatile__( ".set push\n\t" ".set noat\n\t" "# mfgc0 $1, $%1, %2\n\t" _ASM_INSN_IF_MIPS(0x40610000 | %1 << 11 | %2) _ASM_INSN32_IF_MM(0x002004fc | %1 << 16 | %2 << 11) "move %0, $1\n\t" ".set pop" : "=r" (__res) : "i" (source), "i" (sel)); Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13310/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Spelling fix lets -> let'sRalf Baechle
As noticed by Sergei in the discussion of Andrea Gelmini's patch series. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
2016-05-28MIPS: VR41xx: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13338/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: oprofile: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: rric@kernel.org Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Cc: oprofile-list@lists.sf.net Patchwork: https://patchwork.linux-mips.org/patch/13334/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: math-emu: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: macro@imgtec.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13333/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: lib: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13331/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: kernel: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: paul.burton@imgtec.com Cc: macro@imgtec.com Cc: james.hogan@imgtec.com Cc: jslaby@suse.cz Cc: adam.buchbinder@gmail.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13330/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: R6: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: macro@imgtec.com Cc: paul.burton@imgtec.com Cc: Leonid.Yegoshin@imgtec.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13329/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: IP22/IP28: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: adam.buchbinder@gmail.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13328/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Cavium: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: david.daney@cavium.com Cc: janne.huttunen@nokia.com Cc: aaro.koskinen@nokia.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13324/ Patchwork: https://patchwork.linux-mips.org/patch/13325/ Patchwork: https://patchwork.linux-mips.org/patch/13326/ Patchwork: https://patchwork.linux-mips.org/patch/13327/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: MT: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13323/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Loongson64: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: chenhc@lemote.com Cc: viresh.kumar@linaro.org Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13322/ Patchwork: https://patchwork.linux-mips.org/patch/13332/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: IP32: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13321/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: IP27: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13320/ Patchwork: https://patchwork.linux-mips.org/patch/13335/ Patchwork: https://patchwork.linux-mips.org/patch/13336/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: BCM63xx: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13319/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Alchemy: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13318/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: hazards.h: Fix typoAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: chenhc@lemote.com Cc: james.hogan@imgtec.com Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13317/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Lasat: A couple off by one bugs in picvue_proc.cDan Carpenter
These should be ">=" instead of ">" or we go past the end of the pvc_lines[] array. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: linux-mips@linux-mips.org Cc: kernel-janitors@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/6124/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: ralink: add MT7628 EPHY LEDs pinmux supportÁlvaro Fernández Rojas
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Cc: john@phrozen.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13308/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: ralink: fix MT7628 wled_an pinmux gpioÁlvaro Fernández Rojas
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Cc: john@phrozen.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13307/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: ralink: fix MT7628 pinmux typosÁlvaro Fernández Rojas
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Cc: john@phrozen.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13306/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Fix write_gc0_* macros when writing zeroJames Hogan
The versions of the __write_{32,64}bit_gc0_register() macros for when there is no virt support in the assembler use the "J" inline asm constraint to allow integer zero, but this needs to be accompanied by the "z" formatting string so that it turns into $0. Fix both macros to do this. Fixes: bad50d79255a ("MIPS: Fix VZ probe gas errors with binutils <2.24") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13289/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: CPS: Copy EVA configuration when starting secondary VPs.Matt Redfearn
When starting secondary VPEs which support EVA and the SegCtl registers, copy the memory segmentation configuration from the running VPE to ensure that all VPEs in the core have a consistent virtual memory map. The EVA configuration of secondary cores is dealt with when starting the core via the CM. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13291/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add definitions of SegCtl registers and use themMatt Redfearn
The SegCtl registers are standard for MIPSr3..MIPSr5. Add definitions of these registers and use them rather than constants Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: Chris Packham <judge.packham@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13290/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Fix incomplete separation of XPA CPU featureJames Hogan
Commit 12822570a29b ("MIPS: Separate XPA CPU feature into LPA and MVH") wasn't fully applied, possibly due to a conflict with commit f270d881fa55 ("MIPS: Detect MIPSr6 Virtual Processor support"). This left decode_config5() referring to the non-existent MIPS_CPU_XPA, which breaks the build when XPA is enabled: arch/mips/kernel/cpu-probe.c In function ‘decode_config5’: arch/mips/kernel/cpu-probe.c:838:17: error: ‘MIPS_CPU_XPA’ undeclared (first use in this function) c->options |= MIPS_CPU_XPA; ^ Apply the missing hunk, dropping the CONFIG_XPA ifdef and setting the MIPS_CPU_MVH option when Config5.MVH is set. Fixes: 12822570a29b ("MIPS: Separate XPA CPU feature into LPA and MVH") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Link: https://patchwork.linux-mips.org/patch/13112/ Patchwork: https://patchwork.linux-mips.org/patch/13277/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: smp-cps: Clear Status IPL field when using EICPaul Burton
When using an external interrupt controller (EIC) the interrupt mask bits in the cop0 Status register are reused for the Interrupt Priority Level, and any interrupts with a priority lower than the field will be ignored. Clear the field to 0 by default such that all interrupts are serviced. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: Matt Redfearn <matt.redfearn@imgtec.com> Tested-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Qais Yousef <qsyousef@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13273/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Clear Status IPL field when using EICPaul Burton
When using an external interrupt controller (EIC) the interrupt mask bits in the cop0 Status register are reused for the Interrupt Priority Level, and any interrupts with a priority lower than the field will be ignored. Clear the field to 0 by default such that all interrupts are serviced. Without doing so we default to arbitrarily ignoring all or some subset of interrupts. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: Matt Redfearn <matt.redfearn@imgtec.com> Tested-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: Joe Perches <joe@perches.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13272/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-25Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Mostly tooling and PMU driver fixes, but also a number of late updates such as the reworking of the call-chain size limiting logic to make call-graph recording more robust, plus tooling side changes for the new 'backwards ring-buffer' extension to the perf ring-buffer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) perf record: Read from backward ring buffer perf record: Rename variable to make code clear perf record: Prevent reading invalid data in record__mmap_read perf evlist: Add API to pause/resume perf trace: Use the ptr->name beautifier as default for "filename" args perf trace: Use the fd->name beautifier as default for "fd" args perf report: Add srcline_from/to branch sort keys perf evsel: Record fd into perf_mmap perf evsel: Add overwrite attribute and check write_backward perf tools: Set buildid dir under symfs when --symfs is provided perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced perf annotate: Sort list of recognised instructions perf annotate: Fix identification of ARM blt and bls instructions perf tools: Fix usage of max_stack sysctl perf callchain: Stop validating callchains by the max_stack sysctl perf trace: Fix exit_group() formatting perf top: Use machine->kptr_restrict_warned perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1 perf machine: Do not bail out if not managing to read ref reloc symbol perf/x86/intel/p4: Trival indentation fix, remove space ...
2016-05-24Merge tag 'for-linus-20160523' of git://git.infradead.org/linux-mtdLinus Torvalds
Pull MTD updates from Brian Norris: "First cycle with Boris as NAND maintainer! Many (most) bullets stolen from him. Generic: - Migrated NAND LED trigger to be a generic MTD trigger NAND: - Introduction of the "ECC algorithm" concept, to avoid overloading the ECC mode field too much more - Replaced the nand_ecclayout infrastructure with something a little more flexible (finally!) and future proof - Rework of the OMAP GPMC and NAND drivers; the TI folks pulled some of this into their own tree as well - Prepare the sunxi NAND driver to receive DMA support - Handle bitflips in erased pages on GPMI revisions that do not support this in hardware. SPI NOR: - Start using the spi_flash_read() API for SPI drivers that support it (i.e., SPI drivers with special memory-mapped flash modes) And other small scattered improvments" * tag 'for-linus-20160523' of git://git.infradead.org/linux-mtd: (155 commits) mtd: spi-nor: support GigaDevice gd25lq64c mtd: nand_bch: fix spelling of "probably" mtd: brcmnand: respect ECC algorithm set by NAND subsystem gpmi-nand: Handle ECC Errors in erased pages Documentation: devicetree: deprecate "soft_bch" nand-ecc-mode value mtd: nand: add support for "nand-ecc-algo" DT property mtd: mtd: drop NAND_ECC_SOFT_BCH enum value mtd: drop support for NAND_ECC_SOFT_BCH as "soft_bch" mapping mtd: nand: read ECC algorithm from the new field mtd: nand: fsmc: validate ECC setup by checking algorithm directly mtd: nand: set ECC algorithm to Hamming on fallback staging: mt29f_spinand: set ECC algorithm explicitly CRIS v32: nand: set ECC algorithm explicitly mtd: nand: atmel: set ECC algorithm explicitly mtd: nand: davinci: set ECC algorithm explicitly mtd: nand: bf5xx: set ECC algorithm explicitly mtd: nand: omap2: Fix high memory dma prefetch transfer mtd: nand: omap2: Start dma request before enabling prefetch mtd: nandsim: add __init attribute mtd: nand: move of_get_nand_xxx() helpers into nand_base.c ...
2016-05-23vdso: make arch_setup_additional_pages wait for mmap_sem for write killableMichal Hocko
most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Andy Lutomirski <luto@amacapital.net> [x86 vdso] Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23arch/defconfig: remove CONFIG_RESOURCE_COUNTERSKonstantin Khlebnikov
This option was replaced by PAGE_COUNTER which is selected by MEMCG. Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23ELF/MIPS build fixRalf Baechle
CONFIG_MIPS32_N32=y but CONFIG_BINFMT_ELF disabled results in the following linker errors: arch/mips/built-in.o: In function `elf_core_dump': binfmt_elfn32.c:(.text+0x23dbc): undefined reference to `elf_core_extra_phdrs' binfmt_elfn32.c:(.text+0x246e4): undefined reference to `elf_core_extra_data_size' binfmt_elfn32.c:(.text+0x248d0): undefined reference to `elf_core_write_extra_phdrs' binfmt_elfn32.c:(.text+0x24ac4): undefined reference to `elf_core_write_extra_data' CONFIG_MIPS32_O32=y but CONFIG_BINFMT_ELF disabled results in the following linker errors: arch/mips/built-in.o: In function `elf_core_dump': binfmt_elfo32.c:(.text+0x28a04): undefined reference to `elf_core_extra_phdrs' binfmt_elfo32.c:(.text+0x29330): undefined reference to `elf_core_extra_data_size' binfmt_elfo32.c:(.text+0x2951c): undefined reference to `elf_core_write_extra_phdrs' binfmt_elfo32.c:(.text+0x29710): undefined reference to `elf_core_write_extra_data' This is because binfmt_elfn32 and binfmt_elfo32 are using symbols from elfcore but for these configurations elfcore will not be built. Fixed by making elfcore selectable by a separate config symbol which unlike the current mechanism can also be used from other directories than kernel/, then having each flavor of ELF that relies on elfcore.o, select it in Kconfig, including CONFIG_MIPS32_N32 and CONFIG_MIPS32_O32 which fixes this issue. Link: http://lkml.kernel.org/r/20160520141705.GA1913@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - the rest of MM - KASAN updates - procfs updates - exit, fork updates - printk updates - lib/ updates - radix-tree testsuite updates - checkpatch updates - kprobes updates - a few other misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits) samples/kprobes: print out the symbol name for the hooks samples/kprobes: add a new module parameter kprobes: add the "tls" argument for j_do_fork init/main.c: simplify initcall_blacklisted() fs/efs/super.c: fix return value checkpatch: improve --git <commit-count> shortcut checkpatch: reduce number of `git log` calls with --git checkpatch: add support to check already applied git commits checkpatch: add --list-types to show message types to show or ignore checkpatch: advertise the --fix and --fix-inplace options more checkpatch: whine about ACCESS_ONCE checkpatch: add test for keywords not starting on tabstops checkpatch: improve CONSTANT_COMPARISON test for structure members checkpatch: add PREFER_IS_ENABLED test lib/GCD.c: use binary GCD algorithm instead of Euclidean radix-tree: free up the bottom bit of exceptional entries for reuse dax: move RADIX_DAX_ definitions to dax.c radix-tree: make radix_tree_descend() more useful radix-tree: introduce radix_tree_replace_clear_tags() radix-tree: tidy up __radix_tree_create() ...
2016-05-20Merge tag 'tty-4.7-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty and serial driver updates from Greg KH: "Here's the large TTY and Serial driver update for 4.7-rc1. A few new serial drivers are added here, and Peter has fixed a bunch of long-standing bugs in the tty layer and serial drivers as normal. Full details in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'tty-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (88 commits) MAINTAINERS: 8250: remove website reference serial: core: Fix port mutex assert if lockdep disabled serial: 8250_dw: fix wrong logic in dw8250_check_lcr() tty: vt, finish looping on duplicate tty: vt, return error when con_startup fails QE-UART: add "fsl,t1040-ucc-uart" to of_device_id serial: mctrl_gpio: Drop support for out1-gpios and out2-gpios serial: 8250dw: Add device HID for future AMD UART controller Fix OpenSSH pty regression on close serial: mctrl_gpio: add IRQ locking serial: 8250: Integrate Fintek into 8250_base serial: mps2-uart: add support for early console serial: mps2-uart: add MPS2 UART driver dt-bindings: document the MPS2 UART bindings serial: sirf: Use generic uart-has-rtscts DT property serial: sirf: Introduce helper variable struct device_node *np serial: mxs-auart: Use generic uart-has-rtscts DT property serial: imx: Use generic uart-has-rtscts DT property doc: DT: Add Generic Serial Device Tree Bindings serial: 8250: of: Make tegra_serial_handle_break() static ...
2016-05-20lib/GCD.c: use binary GCD algorithm instead of EuclideanZhaoxiu Zeng
The binary GCD algorithm is based on the following facts: 1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2) 2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b) 3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b) Even on x86 machines with reasonable division hardware, the binary algorithm runs about 25% faster (80% the execution time) than the division-based Euclidian algorithm. On platforms like Alpha and ARMv6 where division is a function call to emulation code, it's even more significant. There are two variants of the code here, depending on whether a fast __ffs (find least significant set bit) instruction is available. This allows the unpredictable branches in the bit-at-a-time shifting loop to be eliminated. If fast __ffs is not available, the "even/odd" GCD variant is used. I use the following code to benchmark: #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <time.h> #include <unistd.h> #define swap(a, b) \ do { \ a ^= b; \ b ^= a; \ a ^= b; \ } while (0) unsigned long gcd0(unsigned long a, unsigned long b) { unsigned long r; if (a < b) { swap(a, b); } if (b == 0) return a; while ((r = a % b) != 0) { a = b; b = r; } return b; } unsigned long gcd1(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); for (;;) { a >>= __builtin_ctzl(a); if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd2(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; for (;;) { while (!(a & r)) a >>= 1; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } unsigned long gcd3(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); if (b == 1) return r & -r; for (;;) { a >>= __builtin_ctzl(a); if (a == 1) return r & -r; if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd4(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = { gcd0, gcd1, gcd2, gcd3, gcd4, }; #define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0])) #if defined(__x86_64__) #define rdtscll(val) do { \ unsigned long __a,__d; \ __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \ (val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \ } while(0) static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { unsigned long long start, end; unsigned long long ret; unsigned long gcd_res; rdtscll(start); gcd_res = gcd(a, b); rdtscll(end); if (end >= start) ret = end - start; else ret = ~0ULL - start + 1 + end; *res = gcd_res; return ret; } #else static inline struct timespec read_time(void) { struct timespec time; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time); return time; } static inline unsigned long long diff_time(struct timespec start, struct timespec end) { struct timespec temp; if ((end.tv_nsec - start.tv_nsec) < 0) { temp.tv_sec = end.tv_sec - start.tv_sec - 1; temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec; } else { temp.tv_sec = end.tv_sec - start.tv_sec; temp.tv_nsec = end.tv_nsec - start.tv_nsec; } return temp.tv_sec * 1000000000ULL + temp.tv_nsec; } static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { struct timespec start, end; unsigned long gcd_res; start = read_time(); gcd_res = gcd(a, b); end = read_time(); *res = gcd_res; return diff_time(start, end); } #endif static inline unsigned long get_rand() { if (sizeof(long) == 8) return (unsigned long)rand() << 32 | rand(); else return rand(); } int main(int argc, char **argv) { unsigned int seed = time(0); int loops = 100; int repeats = 1000; unsigned long (*res)[TEST_ENTRIES]; unsigned long long elapsed[TEST_ENTRIES]; int i, j, k; for (;;) { int opt = getopt(argc, argv, "n:r:s:"); /* End condition always first */ if (opt == -1) break; switch (opt) { case 'n': loops = atoi(optarg); break; case 'r': repeats = atoi(optarg); break; case 's': seed = strtoul(optarg, NULL, 10); break; default: /* You won't actually get here. */ break; } } res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops); memset(elapsed, 0, sizeof(elapsed)); srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); /* Do we have args? */ unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); unsigned long long min_elapsed[TEST_ENTRIES]; for (k = 0; k < repeats; k++) { for (i = 0; i < TEST_ENTRIES; i++) { unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]); if (k == 0 || min_elapsed[i] > tmp) min_elapsed[i] = tmp; } } for (i = 0; i < TEST_ENTRIES; i++) elapsed[i] += min_elapsed[i]; } for (i = 0; i < TEST_ENTRIES; i++) printf("gcd%d: elapsed %llu\n", i, elapsed[i]); k = 0; srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); for (i = 1; i < TEST_ENTRIES; i++) { if (res[j][i] != res[j][0]) break; } if (i < TEST_ENTRIES) { if (k == 0) { k = 1; fprintf(stderr, "Error:\n"); } fprintf(stderr, "gcd(%lu, %lu): ", a, b); for (i = 0; i < TEST_ENTRIES; i++) fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n"); } } if (k == 0) fprintf(stderr, "PASS\n"); free(res); return 0; } Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got: zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 10174 gcd1: elapsed 2120 gcd2: elapsed 2902 gcd3: elapsed 2039 gcd4: elapsed 2812 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9309 gcd1: elapsed 2280 gcd2: elapsed 2822 gcd3: elapsed 2217 gcd4: elapsed 2710 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9589 gcd1: elapsed 2098 gcd2: elapsed 2815 gcd3: elapsed 2030 gcd4: elapsed 2718 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9914 gcd1: elapsed 2309 gcd2: elapsed 2779 gcd3: elapsed 2228 gcd4: elapsed 2709 PASS [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable] Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20printk/nmi: generic solution for safe printk in NMIPetr Mladek
printk() takes some locks and could not be used a safe way in NMI context. The chance of a deadlock is real especially when printing stacks from all CPUs. This particular problem has been addressed on x86 by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). The patchset brings two big advantages. First, it makes the NMI backtraces safe on all architectures for free. Second, it makes all NMI messages almost safe on all architectures (the temporary buffer is limited. We still should keep the number of messages in NMI context at minimum). Note that there already are several messages printed in NMI context: WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE handlers. These are not easy to avoid. This patch reuses most of the code and makes it generic. It is useful for all messages and architectures that support NMI. The alternative printk_func is set when entering and is reseted when leaving NMI context. It queues IRQ work to copy the messages into the main ring buffer in a safe context. __printk_nmi_flush() copies all available messages and reset the buffer. Then we could use a simple cmpxchg operations to get synchronized with writers. There is also used a spinlock to get synchronized with other flushers. We do not longer use seq_buf because it depends on external lock. It would be hard to make all supported operations safe for a lockless use. It would be confusing and error prone to make only some operations safe. The code is put into separate printk/nmi.c as suggested by Steven Rostedt. It needs a per-CPU buffer and is compiled only on architectures that call nmi_enter(). This is achieved by the new HAVE_NMI Kconfig flag. The are MN10300 and Xtensa architectures. We need to clean up NMI handling there first. Let's do it separately. The patch is heavily based on the draft from Peter Zijlstra, see https://lkml.org/lkml/2015/6/10/327 [arnd@arndb.de: printk-nmi: use %zu format string for size_t] [akpm@linux-foundation.org: min_t->min - all types are size_t here] Signed-off-by: Petr Mladek <pmladek@suse.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jan Kara <jack@suse.cz> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> [arm part] Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>