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2019-04-05syscalls: Remove start and number from syscall_get_arguments() argsSteven Rostedt (Red Hat)
At Linux Plumbers, Andy Lutomirski approached me and pointed out that the function call syscall_get_arguments() implemented in x86 was horribly written and not optimized for the standard case of passing in 0 and 6 for the starting index and the number of system calls to get. When looking at all the users of this function, I discovered that all instances pass in only 0 and 6 for these arguments. Instead of having this function handle different cases that are never used, simply rewrite it to return the first 6 arguments of a system call. This should help out the performance of tracing system calls by ptrace, ftrace and perf. Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dave Martin <dave.martin@arm.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86 Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-03-28KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supportedMasahiro Yamada
I do not see any consistency about headers_install of <linux/kvm_para.h> and <asm/kvm_para.h>. According to my analysis of Linux 5.1-rc1, there are 3 groups: [1] Both <linux/kvm_para.h> and <asm/kvm_para.h> are exported alpha, arm, hexagon, mips, powerpc, s390, sparc, x86 [2] <asm/kvm_para.h> is exported, but <linux/kvm_para.h> is not arc, arm64, c6x, h8300, ia64, m68k, microblaze, nios2, openrisc, parisc, sh, unicore32, xtensa [3] Neither <linux/kvm_para.h> nor <asm/kvm_para.h> is exported csky, nds32, riscv This does not match to the actual KVM support. At least, [2] is half-baked. Nor do arch maintainers look like they care about this. For example, commit 0add53713b1c ("microblaze: Add missing kvm_para.h to Kbuild") exported <asm/kvm_para.h> to user-space in order to fix an in-kernel build error. We have two ways to make this consistent: [A] export both <linux/kvm_para.h> and <asm/kvm_para.h> for all architectures, irrespective of the KVM support [B] Match the header export of <linux/kvm_para.h> and <asm/kvm_para.h> to the KVM support My first attempt was [A] because the code looks cleaner, but Paolo suggested [B]. So, this commit goes with [B]. For most architectures, <asm/kvm_para.h> was moved to the kernel-space. I changed include/uapi/linux/Kbuild so that it checks generated asm/kvm_para.h as well as check-in ones. After this commit, there will be two groups: [1] Both <linux/kvm_para.h> and <asm/kvm_para.h> are exported arm, arm64, mips, powerpc, s390, x86 [2] Neither <linux/kvm_para.h> nor <asm/kvm_para.h> is exported alpha, arc, c6x, csky, h8300, hexagon, ia64, m68k, microblaze, nds32, nios2, openrisc, parisc, riscv, sh, sparc, unicore32, xtensa Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-20Merge tag 'arc-5.1-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC updates from Vineet Gupta: - unaligned access support for HS cores - Removed extra memory barrier around spinlock code - HSDK platform updates: enable dmac, reset - some more boot logging updates - misc minor fixes * tag 'arc-5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: arch: arc: Kconfig: pedantic formatting ARCv2: spinlock: remove the extra smp_mb before lock, after unlock ARC: unaligned: relax the check for gcc supporting -mno-unaligned-access ARC: boot log: cut down on verbosity ARCv2: boot log: refurbish HS core/release identification arc: hsdk_defconfig: Enable CONFIG_BLK_DEV_RAM ARC: u-boot args: check that magic number is correct ARC: perf: bpok condition only exists for ARCompact ARCv2: Add explcit unaligned access support (and ability to disable too) ARCv2: lib: introduce memcpy optimized for unaligned access ARC: [plat-hsdk]: Enable AXI DW DMAC support ARC: [plat-hsdk]: Add reset controller handle to manage USB reset ARC: DTB: [scripted] fix node name and address spelling
2019-03-17kbuild: force all architectures except um to include mandatory-yMasahiro Yamada
Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-12memblock: drop memblock_alloc_*_nopanic() variantsMike Rapoport
As all the memblock allocation functions return NULL in case of error rather than panic(), the duplicates with _nopanic suffix can be removed. Link: http://lkml.kernel.org/r/1548057848-15136-22-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [printk] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> [c-sky] Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Juergen Gross <jgross@suse.com> [Xen] Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12treewide: add checks for the return value of memblock_alloc*()Mike Rapoport
Add check for the return value of memblock_alloc*() functions and call panic() in case of error. The panic message repeats the one used by panicing memblock allocators with adjustment of parameters to include only relevant ones. The replacement was mostly automated with semantic patches like the one below with manual massaging of format strings. @@ expression ptr, size, align; @@ ptr = memblock_alloc(size, align); + if (!ptr) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align); [anders.roxell@linaro.org: use '%pa' with 'phys_addr_t' type] Link: http://lkml.kernel.org/r/20190131161046.21886-1-anders.roxell@linaro.org [rppt@linux.ibm.com: fix format strings for panics after memblock_alloc] Link: http://lkml.kernel.org/r/1548950940-15145-1-git-send-email-rppt@linux.ibm.com [rppt@linux.ibm.com: don't panic if the allocation in sparse_buffer_init fails] Link: http://lkml.kernel.org/r/20190131074018.GD28876@rapoport-lnx [akpm@linux-foundation.org: fix xtensa printk warning] Link: http://lkml.kernel.org/r/1548057848-15136-20-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Reviewed-by: Guo Ren <ren_guo@c-sky.com> [c-sky] Acked-by: Paul Burton <paul.burton@mips.com> [MIPS] Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390] Reviewed-by: Juergen Gross <jgross@suse.com> [Xen] Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-11arch: arc: Kconfig: pedantic formattingEnrico Weigelt, metux IT consult
Formatting of Kconfig files doesn't look so pretty, so let the Great White Handkerchief come around and clean it up. Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-03-10Merge tag 'dma-mapping-5.1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull DMA mapping updates from Christoph Hellwig: - add debugfs support for dumping dma-debug information (Corentin Labbe) - Kconfig cleanups (Andy Shevchenko and me) - debugfs cleanups (Greg Kroah-Hartman) - improve dma_map_resource and use it in the media code - arch_setup_dma_ops / arch_teardown_dma_ops cleanups - various small cleanups and improvements for the per-device coherent allocator - make the DMA mask an upper bound and don't fail "too large" dma mask in the remaning two architectures - this will allow big driver cleanups in the following merge windows * tag 'dma-mapping-5.1' of git://git.infradead.org/users/hch/dma-mapping: (21 commits) Documentation/DMA-API-HOWTO: update dma_mask sections sparc64/pci_sun4v: allow large DMA masks sparc64/iommu: allow large DMA masks sparc64: refactor the ali DMA quirk ccio: allow large DMA masks dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flag dma-mapping: remove dma_mark_declared_memory_occupied dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig dma-mapping: improve selection of dma_declare_coherent availability dma-mapping: remove an incorrect __iommem annotation of: select OF_RESERVED_MEM automatically device.h: dma_mem is only needed for HAVE_GENERIC_DMA_COHERENT mfd/sm501: depend on HAS_DMA dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availability dma-mapping: add a kconfig symbol for arch_setup_dma_ops availability dma-mapping: move debug configuration options to kernel/dma dma-debug: add dumping facility via debugfs dma: debug: no need to check return value of debugfs_create functions videobuf2: replace a layering violation with dma_map_resource dma-mapping: don't BUG when calling dma_map_resource on RAM ...
2019-03-08ARCv2: spinlock: remove the extra smp_mb before lock, after unlockVineet Gupta
- ARCv2 LLSC spinlocks have smp_mb() both before and after the LLSC instructions, which is not required per lkmm ACQ/REL semantics. smp_mb() is only needed _after_ lock and _before_ unlock. So remove the extra barriers. The reason they were there was mainly historical. At the time of initial SMP Linux bringup on HS38 cores, I was too conservative, given the fluidity of both hw and sw. The last attempt to ditch the extra barrier showed some hackbench regression which is apparently not the case now (atleast for LLSC case, read on...) - EX based spinlocks (!CONFIG_ARC_HAS_LLSC) still needs the extra smp_mb(), not due to lkmm, but due to some hardware shenanigans. W/o that, hackbench triggers RCU stall splat so extra DMB is retained !LLSC based systems are not realistic Linux sstem anyways so they can afford to be a nit suboptimal ;-) | [ARCLinux]# for i in (seq 1 1 5) ; do hackbench; done | Running with 10 groups 400 process | INFO: task hackbench:158 blocked for more than 10 seconds. | Not tainted 4.20.0-00005-g96b18288a88e-dirty #117 | "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. | hackbench D 0 158 135 0x00000000 | | Stack Trace: | watchdog: BUG: soft lockup - CPU#3 stuck for 59s! [hackbench:469] | Modules linked in: | Path: (null) | CPU: 3 PID: 469 Comm: hackbench Not tainted 4.20.0-00005-g96b18288a88e-dirty | | [ECR ]: 0x00000000 => Check Programmer's Manual | [EFA ]: 0x00000000 | [BLINK ]: do_exit+0x4a6/0x7d0 | [ERET ]: _raw_write_unlock_irq+0x44/0x5c - And while at it, remove the extar smp_mb() from EX based arch_read_trylock() since the spin lock there guarantees a full barrier anyways - For LLSC case, hackbench threads improves with this patch (HAPS @ 50MHz) ---- before ---- | | [ARCLinux]# for i in 1 2 3 4 5; do hackbench 10 thread; done | Running with 10 groups 400 threads | Time: 16.253 | Time: 16.445 | Time: 16.590 | Time: 16.721 | Time: 16.544 ---- after ---- | | [ARCLinux]# for i in 1 2 3 4 5; do hackbench 10 thread; done | Running with 10 groups 400 threads | Time: 15.638 | Time: 15.730 | Time: 15.870 | Time: 15.842 | Time: 15.729 Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-03-07configs: get rid of obsolete CONFIG_ENABLE_WARN_DEPRECATEDAlexey Brodkin
This Kconfig option was removed during v4.19 development in commit 771c035372a0 ("deprecate the '__deprecated' attribute warnings entirely and for good") so there's no point to keep it in defconfigs any longer. FWIW defconfigs were patched with: --------------------------->8---------------------- find . -name *_defconfig -exec sed -i '/CONFIG_ENABLE_WARN_DEPRECATED/d' {} \; --------------------------->8---------------------- Link: http://lkml.kernel.org/r/20190128152434.41969-1-abrodkin@synopsys.com Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05Merge branch 'timers-2038-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull year 2038 updates from Thomas Gleixner: "Another round of changes to make the kernel ready for 2038. After lots of preparatory work this is the first set of syscalls which are 2038 safe: 403 clock_gettime64 404 clock_settime64 405 clock_adjtime64 406 clock_getres_time64 407 clock_nanosleep_time64 408 timer_gettime64 409 timer_settime64 410 timerfd_gettime64 411 timerfd_settime64 412 utimensat_time64 413 pselect6_time64 414 ppoll_time64 416 io_pgetevents_time64 417 recvmmsg_time64 418 mq_timedsend_time64 419 mq_timedreceiv_time64 420 semtimedop_time64 421 rt_sigtimedwait_time64 422 futex_time64 423 sched_rr_get_interval_time64 The syscall numbers are identical all over the architectures" * 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) riscv: Use latest system call ABI checksyscalls: fix up mq_timedreceive and stat exceptions unicore32: Fix __ARCH_WANT_STAT64 definition asm-generic: Make time32 syscall numbers optional asm-generic: Drop getrlimit and setrlimit syscalls from default list 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option compat ABI: use non-compat openat and open_by_handle_at variants y2038: add 64-bit time_t syscalls to all 32-bit architectures y2038: rename old time and utime syscalls y2038: remove struct definition redirects y2038: use time32 syscall names on 32-bit syscalls: remove obsolete __IGNORE_ macros y2038: syscalls: rename y2038 compat syscalls x86/x32: use time64 versions of sigtimedwait and recvmmsg timex: change syscalls to use struct __kernel_timex timex: use __kernel_timex internally sparc64: add custom adjtimex/clock_adjtime functions time: fix sys_timer_settime prototype time: Add struct __kernel_timex time: make adjtime compat handling available for 32 bit ...
2019-03-05ARC: unaligned: relax the check for gcc supporting -mno-unaligned-accessVineet Gupta
Without bleeding edge gcc, kernel builds were tripping everywhere. So current gcc will generate unaligned code despite !CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS but that is something we have to live with. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-27Merge tag 'y2038-syscall-abi' of ↵Thomas Gleixner
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground into timers/2038 Pull additional syscall ABI cleanup for y2038 from Arnd Bergmann: This is a follow-up to the y2038 syscall patches already merged in the tip tree. As the final 32-bit RISC-V syscall ABI is still being decided on, this is the last chance to make a few corrections to leave out interfaces based on 32-bit time_t along with the old off_t and rlimit types. The series achieves this in a few steps: - A couple of bug fixes for minor regressions I introduced in the original series - A couple of older patches from Yury Norov that I had never merged in the past, these fix up the openat/open_by_handle_at and getrlimit/setrlimit syscalls to disallow the old versions of off_t and rlimit. - Hiding the deprecated system calls behind an #ifdef in include/uapi/asm-generic/unistd.h - Change arch/riscv to drop all these ABIs. Originally, the plan was to also leave these out on C-Sky, but that now has a glibc port that uses the older interfaces, so we need to leave them in place.
2019-02-25ARC: boot log: cut down on verbosityVineet Gupta
The syscall ABI has long been fixed, so no need to call that out now. Also, there's no need to print really fine details such as norm, barrel-shifter etc. Those are given in a Linux enabled hardware config. So now we print just 1 line for all optional "instruction" related hardware features | | ISA Extn : atomic ll64 unalign mpy[opt 9] div_rem vs. 2 before | |ISA Extn : atomic ll64 unalign | : mpy[opt 9] div_rem norm barrel-shift swap minmax swape Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARCv2: boot log: refurbish HS core/release identificationVineet Gupta
HS core names and releases have so far been identified based solely on IDENTIFY.ARCVER field. With the future HS releases this will not be sufficient as same ARCVER 0x54 could be an HS38 or HS48. So rewrite the code to use a new BCR to identify the cores properly. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25arc: hsdk_defconfig: Enable CONFIG_BLK_DEV_RAMCorentin Labbe
We have now a HSDK device in our kernelci lab, but kernel builded via the hsdk_defconfig lacks ramfs supports, so it cannot boot kernelci jobs yet. So this patch enable CONFIG_BLK_DEV_RAM in hsdk_defconfig. Signed-off-by: Corentin Labbe <clabbe@baylibre.com> Acked-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARC: u-boot args: check that magic number is correctEugeniy Paltsev
In case of devboards we really often disable bootloader and load Linux image in memory via JTAG. Even if kernel tries to verify uboot_tag and uboot_arg there is sill a chance that we treat some garbage in registers as valid u-boot arguments in JTAG case. E.g. it is enough to have '1' in r0 to treat any value in r2 as a boot command line. So check that magic number passed from u-boot is correct and drop u-boot arguments otherwise. That helps to reduce the possibility of using garbage as u-boot arguments in JTAG case. We can safely check U-boot magic value (0x0) in linux passed via r1 register as U-boot pass it from the beginning. So there is no backward-compatibility issues. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARC: perf: bpok condition only exists for ARCompactVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARCv2: Add explcit unaligned access support (and ability to disable too)Eugeniy Paltsev
As of today we enable unaligned access unconditionally on ARCv2. Do this under a Kconfig option to allow disable it for test, benchmarking etc. Also while at it - Select HAVE_EFFICIENT_UNALIGNED_ACCESS - Although gcc defaults to unaligned access (since GNU 2018.03), add the right toggles for enabling or disabling as appropriate - update bootlog to prints both HW feature status (exists, enabled/disabled) and SW status (used / not used). - wire up the relaxed memcpy for unaligned access Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: squashed patches, handle gcc -mno-unaligned-access quick]
2019-02-25ARCv2: lib: introduce memcpy optimized for unaligned accessEugeniy Paltsev
Optimise code to use efficient unaligned memory access which is available on ARCv2. This allows us to really simplify memcpy code and speed up the code one and a half times (in case of unaligned source or destination). Don't wire it up yet ! Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARC: [plat-hsdk]: Enable AXI DW DMAC supportEugeniy Paltsev
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARC: [plat-hsdk]: Add reset controller handle to manage USB resetEugeniy Paltsev
DW USB controller on HSDK hangs sometimes after SW reset, so add reset handle to make possible to reset DW USB controller HW. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25ARC: DTB: [scripted] fix node name and address spellingAlexey Brodkin
1. Remove "0x" prefix from unit-address of node names ----------------------->8------------------------ sed -i 's/@0x/@/g' arch/arc/boot/dts/*.dts* ----------------------->8------------------------ 2. Make all hex addresses lowercase: ----------------------->8------------------------ sed -i 's/@\([0-9A-Za-z]*\)/@\L\1/g' arch/arc/boot/dts/*.dts* sed -i 's/0x\([0-9A-Za-z]*\)/0x\L\1/g' arch/arc/boot/dts/*.dts* ----------------------->8------------------------ Inspired by [1] and the like. [1] http://kisskb.ellerman.id.au/kisskb/buildresult/13612017/ Reviewed-by: Rob Herring <robh+dt@kernel.org> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARCv2: don't assume core 0x54 has dual issueVineet Gupta
The first release of core4 (0x54) was dual issue only (HS4x). Newer releases allow hardware to be configured as single issue (HS3x) or dual issue. Prevent accessing a HS4x only aux register in HS3x, which otherwise leads to illegal instruction exceptions Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARC: define ARCH_SLAB_MINALIGN = 8Alexey Brodkin
The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is "__alignof__(unsigned long long)" which for ARC unexpectedly turns out to be 4. This is not a compiler bug, but as defined by ARC ABI [1] Thus slab allocator would allocate a struct which is 32-bit aligned, which is generally OK even if struct has long long members. There was however potetial problem when it had any atomic64_t which use LLOCKD/SCONDD instructions which are required by ISA to take 64-bit addresses. This is the problem we ran into [ 4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 4.167881] Misaligned Access [ 4.172356] Path: /bin/busybox.nosuid [ 4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1 [ 4.182851] [ 4.182851] [ECR ]: 0x000d0000 => Check Programmer's Manual [ 4.190061] [EFA ]: 0xbeaec3fc [ 4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234 [ 4.190061] [ERET ]: ext4_delete_entry+0x13e/0x234 [ 4.202985] [STAT32]: 0x80080002 : IE K [ 4.207236] BTA: 0x9009329c SP: 0xbe5b1ec4 FP: 0x00000000 [ 4.212790] LPS: 0x9074b118 LPE: 0x9074b120 LPC: 0x00000000 [ 4.218348] r00: 0x00000040 r01: 0x00000021 r02: 0x00000001 ... ... [ 4.270510] Stack Trace: [ 4.274510] ext4_delete_entry+0x13e/0x234 [ 4.278695] ext4_rmdir+0xe0/0x238 [ 4.282187] vfs_rmdir+0x50/0xf0 [ 4.285492] do_rmdir+0x9e/0x154 [ 4.288802] EV_Trap+0x110/0x114 The fix is to make sure slab allocations are 64-bit aligned. Do note that atomic64_t is __attribute__((aligned(8)) which means gcc does generate 64-bit aligned references, relative to beginning of container struct. However the issue is if the container itself is not 64-bit aligned, atomic64_t ends up unaligned which is what this patch ensures. [1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: <stable@vger.kernel.org> # 4.8+ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: reworked changelog, added dependency on LL64+LLSC]
2019-02-21ARC: enable uboot support unconditionallyEugeniy Paltsev
After reworking U-boot args handling code and adding paranoid arguments check we can eliminate CONFIG_ARC_UBOOT_SUPPORT and enable uboot support unconditionally. For JTAG case we can assume that core registers will come up reset value of 0 or in worst case we rely on user passing '-on=clear_regs' to Metaware debugger. Cc: stable@vger.kernel.org Tested-by: Corentin LABBE <clabbe@baylibre.com> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARC: U-boot: check arguments paranoidlyEugeniy Paltsev
Handle U-boot arguments paranoidly: * don't allow to pass unknown tag. * try to use external device tree blob only if corresponding tag (TAG_DTB) is set. * don't check uboot_tag if kernel build with no ARC_UBOOT_SUPPORT. NOTE: If U-boot args are invalid we skip them and try to use embedded device tree blob. We can't panic on invalid U-boot args as we really pass invalid args due to bug in U-boot code. This happens if we don't provide external DTB to U-boot and don't set 'bootargs' U-boot environment variable (which is default case at least for HSDK board) In that case we will pass {r0 = 1 (bootargs in r2); r1 = 0; r2 = 0;} to linux which is invalid. While I'm at it refactor U-boot arguments handling code. Cc: stable@vger.kernel.org Tested-by: Corentin LABBE <clabbe@baylibre.com> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARCv2: support manual regfile save on interruptsVineet Gupta
There's a hardware bug which affects the HSDK platform, triggered by micro-ops for auto-saving regfile on taken interrupt. The workaround is to inhibit autosave. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARC: uacces: remove lp_start, lp_end from clobber listVineet Gupta
Newer ARC gcc handles lp_start, lp_end in a different way and doesn't like them in the clobber list. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARC: fix actionpoints configuration detectionEugeniy Paltsev
Fix reversed logic while actionpoints configuration (full/min) detection. Fixies: 7dd380c338f1e ("ARC: boot log: print Action point details") Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARCv2: lib: memcpy: fix doing prefetchw outside of bufferEugeniy Paltsev
ARCv2 optimized memcpy uses PREFETCHW instruction for prefetching the next cache line but doesn't ensure that the line is not past the end of the buffer. PRETECHW changes the line ownership and marks it dirty, which can cause data corruption if this area is used for DMA IO. Fix the issue by avoiding the PREFETCHW. This leads to performance degradation but it is OK as we'll introduce new memcpy implementation optimized for unaligned memory access using. We also cut off all PREFETCH instructions at they are quite useless here: * we call PREFETCH right before LOAD instruction call. * we copy 16 or 32 bytes of data (depending on CONFIG_ARC_HAS_LL64) in a main logical loop. so we call PREFETCH 4 times (or 2 times) for each L1 cache line (in case of 64B L1 cache Line which is default case). Obviously this is not optimal. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-21ARCv2: Enable unaligned access in early ASM codeEugeniy Paltsev
It is currently done in arc_init_IRQ() which might be too late considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned memory accesses by default Cc: stable@vger.kernel.org #4.4+ Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote changelog]
2019-02-20dma-mapping: improve selection of dma_declare_coherent availabilityChristoph Hellwig
This API is primarily used through DT entries, but two architectures and two drivers call it directly. So instead of selecting the config symbol for random architectures pull it in implicitly for the actual users. Also rename the Kconfig option to describe the feature better. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS Acked-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19asm-generic: Make time32 syscall numbers optionalArnd Bergmann
We don't want new architectures to even provide the old 32-bit time_t based system calls any more, or define the syscall number macros. Add a new __ARCH_WANT_TIME32_SYSCALLS macro that gets enabled for all existing 32-bit architectures using the generic system call table, so we don't change any current behavior. Since this symbol is evaluated in user space as well, we cannot use a Kconfig CONFIG_* macro but have to define it in uapi/asm/unistd.h. On 64-bit architectures, the same system call numbers mostly refer to the system calls we want to keep, as they already pass 64-bit time_t. As new architectures no longer provide these, we need new exceptions in checksyscalls.sh. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-19asm-generic: Drop getrlimit and setrlimit syscalls from default listYury Norov
The newer prlimit64 syscall provides all the functionality of getrlimit and setrlimit syscalls and adds the pid of target process, so future architectures won't need to include getrlimit and setrlimit. Therefore drop getrlimit and setrlimit syscalls from the generic syscall list unless __ARCH_WANT_SET_GET_RLIMIT is defined by the architecture's unistd.h prior to including asm-generic/unistd.h, and adjust all architectures using the generic syscall list to define it so that no in-tree architectures are affected. Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-hexagon@vger.kernel.org Cc: uclinux-h8-devel@lists.sourceforge.jp Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Mark Salter <msalter@redhat.com> [c6x] Acked-by: James Hogan <james.hogan@imgtec.com> [metag] Acked-by: Ley Foon Tan <lftan@altera.com> [nios2] Acked-by: Stafford Horne <shorne@gmail.com> [openrisc] Acked-by: Will Deacon <will.deacon@arm.com> [arm64] Acked-by: Vineet Gupta <vgupta@synopsys.com> #arch/arc bits Signed-off-by: Yury Norov <ynorov@marvell.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-1932-bit userspace ABI: introduce ARCH_32BIT_OFF_T config optionYury Norov
All new 32-bit architectures should have 64-bit userspace off_t type, but existing architectures has 32-bit ones. To enforce the rule, new config option is added to arch/Kconfig that defaults ARCH_32BIT_OFF_T to be disabled for new 32-bit architectures. All existing 32-bit architectures enable it explicitly. New option affects force_o_largefile() behaviour. Namely, if userspace off_t is 64-bits long, we have no reason to reject user to open big files. Note that even if architectures has only 64-bit off_t in the kernel (arc, c6x, h8300, hexagon, nios2, openrisc, and unicore32), a libc may use 32-bit off_t, and therefore want to limit the file size to 4GB unless specified differently in the open flags. Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yury Norov <ynorov@marvell.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-13of: select OF_RESERVED_MEM automaticallyChristoph Hellwig
The OF_RESERVED_MEM can be used if we have either CMA or the generic declare coherent code built and we support the early flattened DT. So don't bother making it a user visible options that is selected by most configs that fit the above category, but just select it when the requirements are met. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Rob Herring <robh@kernel.org>
2019-02-13dma-mapping: add a kconfig symbol for arch_setup_dma_ops availabilityChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-01-17ARCv2: lib: memeset: fix doing prefetchw outside of bufferEugeniy Paltsev
ARCv2 optimized memset uses PREFETCHW instruction for prefetching the next cache line but doesn't ensure that the line is not past the end of the buffer. PRETECHW changes the line ownership and marks it dirty, which can cause issues in SMP config when next line was already owned by other core. Fix the issue by avoiding the PREFETCHW Some more details: The current code has 3 logical loops (ignroing the unaligned part) (a) Big loop for doing aligned 64 bytes per iteration with PREALLOC (b) Loop for 32 x 2 bytes with PREFETCHW (c) any left over bytes loop (a) was already eliding the last 64 bytes, so PREALLOC was safe. The fix was removing PREFETCW from (b). Another potential issue (applicable to configs with 32 or 128 byte L1 cache line) is that PREALLOC assumes 64 byte cache line and may not do the right thing specially for 32b. While it would be easy to adapt, there are no known configs with those lie sizes, so for now, just compile out PREALLOC in such cases. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Cc: stable@vger.kernel.org #4.4+ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote changelog, used asm .macro vs. "C" macro]
2019-01-17ARC: mm: do_page_fault fixes #1: relinquish mmap_sem if signal arrives while ↵Vineet Gupta
handle_mm_fault do_page_fault() forgot to relinquish mmap_sem if a signal came while handling handle_mm_fault() - due to say a ctl+c or oom etc. This would later cause a deadlock by acquiring it twice. This came to light when running libc testsuite tst-tls3-malloc test but is likely also the cause for prior seen LTP failures. Using lockdep clearly showed what the issue was. | # while true; do ./tst-tls3-malloc ; done | Didn't expect signal from child: got `Segmentation fault' | ^C | ============================================ | WARNING: possible recursive locking detected | 4.17.0+ #25 Not tainted | -------------------------------------------- | tst-tls3-malloc/510 is trying to acquire lock: | 606c7728 (&mm->mmap_sem){++++}, at: __might_fault+0x28/0x5c | |but task is already holding lock: |606c7728 (&mm->mmap_sem){++++}, at: do_page_fault+0x9c/0x2a0 | | other info that might help us debug this: | Possible unsafe locking scenario: | | CPU0 | ---- | lock(&mm->mmap_sem); | lock(&mm->mmap_sem); | | *** DEADLOCK *** | ------------------------------------------------------------ What the change does is not obvious (note to myself) prior code was | do_page_fault | | down_read() <-- lock taken | handle_mm_fault <-- signal pending as this runs | if fatal_signal_pending | if VM_FAULT_ERROR | up_read | if user_mode | return <-- lock still held, this was the BUG New code | do_page_fault | | down_read() <-- lock taken | handle_mm_fault <-- signal pending as this runs | if fatal_signal_pending | if VM_FAULT_RETRY | return <-- not same case as above, but still OK since | core mm already relinq lock for FAULT_RETRY | ... | | < Now falls through for bug case above > | | up_read() <-- lock relinquished Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: show_regs: lockdep: re-enable preemptionVineet Gupta
signal handling core calls show_regs() with preemption disabled which on ARC takes mmap_sem for mm/vma access, causing lockdep splat. | [ARCLinux]# ./segv-null-ptr | potentially unexpected fatal signal 11. | BUG: sleeping function called from invalid context at kernel/fork.c:1011 | in_atomic(): 1, irqs_disabled(): 0, pid: 70, name: segv-null-ptr | no locks held by segv-null-ptr/70. | CPU: 0 PID: 70 Comm: segv-null-ptr Not tainted 4.18.0+ #69 | | Stack Trace: | arc_unwind_core+0xcc/0x100 | ___might_sleep+0x17a/0x190 | mmput+0x16/0xb8 | show_regs+0x52/0x310 | get_signal+0x5ee/0x610 | do_signal+0x2c/0x218 | resume_user_mode_begin+0x90/0xd8 Workaround by re-enabling preemption temporarily. Note that the preemption disabling in core code around show_regs() was introduced by commit 3a9f84d354ce ("signals, debug: fix BUG: using smp_processor_id() in preemptible code in print_fatal_signal()") to silence a differnt lockdep seen on x86 bakc in 2009. Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: show_regs: lockdep: avoid page allocator...Vineet Gupta
and use smaller/on-stack buffer instead The motivation for this change was lockdep splat like below. | potentially unexpected fatal signal 11. | BUG: sleeping function called from invalid context at ../mm/page_alloc.c:4317 | in_atomic(): 1, irqs_disabled(): 0, pid: 57, name: segv | no locks held by segv/57. | Preemption disabled at: | [<8182f17e>] get_signal+0x4a6/0x7c4 | CPU: 0 PID: 57 Comm: segv Not tainted 4.17.0+ #23 | | Stack Trace: | arc_unwind_core.constprop.1+0xd0/0xf4 | __might_sleep+0x1f6/0x234 | __get_free_pages+0x174/0xca0 | show_regs+0x22/0x330 | get_signal+0x4ac/0x7c4 # print_fatal_signals() -> preempt_disable() | do_signal+0x30/0x224 | resume_user_mode_begin+0x90/0xd8 So signal handling core calls show_regs() with preemption disabled but an ensuing GFP_KERNEL page allocator call is flagged by lockdep. We could have switched to GFP_NOWAIT, but turns out that is not enough anways and eliding page allocator call leads to less code and instruction traces to sift thru when debugging pesky crashes. FWIW, this patch doesn't cure the lockdep splat (which next patch does). Reviewed-by: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: perf: avoid kernel killing where it is possibleEugeniy Paltsev
No, not gonna die tonight. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: perf: move HW events mapping to separate functionEugeniy Paltsev
Move HW events mapping to separate function to make code more readable. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: perf: introduce Kernel PMU events supportEugeniy Paltsev
Export all available ARC architected hardware events as kernel PMU events to make non-generic events accessible. ARC PMU HW allow us to read the list of all available events names. So we generate kernel PMU event list dynamically in arc_pmu_device_probe() using human-readable events names we got from HW instead of using pre-defined events list. -------------------------->8-------------------------- $ perf list [snip] arc_pmu/bdata64/ [Kernel PMU event] arc_pmu/bdcstall/ [Kernel PMU event] arc_pmu/bdslot/ [Kernel PMU event] arc_pmu/bfbmp/ [Kernel PMU event] arc_pmu/bfirqex/ [Kernel PMU event] arc_pmu/bflgstal/ [Kernel PMU event] arc_pmu/bflush/ [Kernel PMU event] -------------------------->8-------------------------- Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: perf: trivial code cleanupEugeniy Paltsev
* Use BIT(), lower_32_bits(), upper_32_bits() macroses, fix code style violations. * Use u32, u64, s64 instead of uint32_t, uint64_t, int64_t * Fix description comment as this code doesn't belong only to ARC700 anymore. * Use SPDX License Identifier. * Remove useless ifdefs. ifdef around 'arc_pmu_match' structure declaration is useless as we refer to 'arc_pmu_match' in several places which aren't guarded with ifdef. Nevertheless 'ARC' option selects 'OF' unconditionally so we can simply get rid of this ifdef. Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: perf: map generic branches to correct hardware conditionEugeniy Paltsev
So far we've mapped branches to "ijmp" which also counts conditional branches NOT taken. This makes us different from other architectures such as ARM which seem to be counting only taken branches. So use "ijmptak" hardware condition which only counts (all jump instructions that are taken) 'ijmptak' event is available on both ARCompact and ARCv2 ISA based cores. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: reworked changelog]
2019-01-17ARC: adjust memblock_reserve of kernel memoryEugeniy Paltsev
In setup_arch_memory we reserve the memory area wherein the kernel is located. Current implementation may reserve more memory than it actually required in case of CONFIG_LINUX_LINK_BASE is not equal to CONFIG_LINUX_RAM_BASE. This happens because we calculate start of the reserved region relatively to the CONFIG_LINUX_RAM_BASE and end of the region relatively to the CONFIG_LINUX_RAM_BASE. For example in case of HSDK board we wasted 256MiB of physical memory: ------------------->8------------------------------ Memory: 770416K/1048576K available (5496K kernel code, 240K rwdata, 1064K rodata, 2200K init, 275K bss, 278160K reserved, 0K cma-reserved) ------------------->8------------------------------ Fix that. Fixes: 9ed68785f7f2b ("ARC: mm: Decouple RAM base address from kernel link addr") Cc: stable@vger.kernel.org #4.14+ Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17arc: remove redundant kernel-space generic-yMasahiro Yamada
This commit removes redundant generic-y defines in arch/arc/include/asm/Kbuild. It is redundant to define generic-y when arch-specific implementation exists in arch/$(ARCH)/include/asm/*.h Remove the following generic-y: dma-mapping.h fb.h kmap_types.h pci.h Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-01-17ARC: fix __ffs return value to avoid build warningsEugeniy Paltsev
| CC mm/nobootmem.o |In file included from ./include/asm-generic/bug.h:18:0, | from ./arch/arc/include/asm/bug.h:32, | from ./include/linux/bug.h:5, | from ./include/linux/mmdebug.h:5, | from ./include/linux/gfp.h:5, | from ./include/linux/slab.h:15, | from mm/nobootmem.c:14: |mm/nobootmem.c: In function '__free_pages_memory': |./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^ |./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck' | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ |./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp' | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ |./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp' | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ |mm/nobootmem.c:104:11: note: in expansion of macro 'min' | order = min(MAX_ORDER - 1UL, __ffs(start)); Change __ffs return value from 'int' to 'unsigned long' as it is done in other implementations (like asm-generic, x86, etc...) to avoid build-time warnings in places where type is strictly checked. As __ffs may return values in [0-31] interval changing return type to unsigned is valid. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>