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2019-04-05ARM: avoid Cortex-A9 livelock on tight dmb loopsRussell King2-1/+7
[ Upstream commit 5388a5b82199facacd3d7ac0d05aca6e8f902fed ] machine_crash_nonpanic_core() does this: while (1) cpu_relax(); because the kernel has crashed, and we have no known safe way to deal with the CPU. So, we place the CPU into an infinite loop which we expect it to never exit - at least not until the system as a whole is reset by some method. In the absence of erratum 754327, this code assembles to: b . In other words, an infinite loop. When erratum 754327 is enabled, this becomes: 1: dmb b 1b It has been observed that on some systems (eg, OMAP4) where, if a crash is triggered, the system tries to kexec into the panic kernel, but fails after taking the secondary CPU down - placing it into one of these loops. This causes the system to livelock, and the most noticable effect is the system stops after issuing: Loading crashdump kernel... to the system console. The tested as working solution I came up with was to add wfe() to these infinite loops thusly: while (1) { cpu_relax(); wfe(); } which, without 754327 builds to: 1: wfe b 1b or with 754327 is enabled: 1: dmb wfe b 1b Adding "wfe" does two things depending on the environment we're running under: - where we're running on bare metal, and the processor implements "wfe", it stops us spinning endlessly in a loop where we're never going to do any useful work. - if we're running in a VM, it allows the CPU to be given back to the hypervisor and rescheduled for other purposes (maybe a different VM) rather than wasting CPU cycles inside a crashed VM. However, in light of erratum 794072, Will Deacon wanted to see 10 nops as well - which is reasonable to cover the case where we have erratum 754327 enabled _and_ we have a processor that doesn't implement the wfe hint. So, we now end up with: 1: wfe b 1b when erratum 754327 is disabled, or: 1: dmb nop nop nop nop nop nop nop nop nop nop wfe b 1b when erratum 754327 is enabled. We also get the dmb + 10 nop sequence elsewhere in the kernel, in terminating loops. This is reasonable - it means we get the workaround for erratum 794072 when erratum 754327 is enabled, but still relinquish the dead processor - either by placing it in a lower power mode when wfe is implemented as such or by returning it to the hypervisior, or in the case where wfe is a no-op, we use the workaround specified in erratum 794072 to avoid the problem. These as two entirely orthogonal problems - the 10 nops addresses erratum 794072, and the wfe is an optimisation that makes the system more efficient when crashed either in terms of power consumption or by allowing the host/other VMs to make use of the CPU. I don't see any reason not to use kexec() inside a VM - it has the potential to provide automated recovery from a failure of the VMs kernel with the opportunity for saving a crashdump of the failure. A panic() with a reboot timeout won't do that, and reading the libvirt documentation, setting on_reboot to "preserve" won't either (the documentation states "The preserve action for an on_reboot event is treated as a destroy".) Surely it has to be a good thing to avoiding having CPUs spinning inside a VM that is doing no useful work. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05ARM: 8830/1: NOMMU: Toggle only bits in EXC_RETURN we are really care ofVladimir Murzin1-1/+1
[ Upstream commit 72cd4064fccaae15ab84d40d4be23667402df4ed ] ARMv8M introduces support for Security extension to M class, among other things it affects exception handling, especially, encoding of EXC_RETURN. The new bits have been added: Bit [6] Secure or Non-secure stack Bit [5] Default callee register stacking Bit [0] Exception Secure which conflicts with hard-coded value of EXC_RETURN: In fact, we only care of few bits: Bit [3] Mode (0 - Handler, 1 - Thread) Bit [2] Stack pointer selection (0 - Main, 1 - Process) We can toggle only those bits and left other bits as they were on exception entry. It is basically, what patch does - saves EXC_RETURN when we do transition form Thread to Handler mode (it is first svc), so later saved value is used instead of EXC_RET_THREADMODE_PROCESSSTACK. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23ARM: 8824/1: fix a migrating irq bug when hotplug cpuDietmar Eggemann1-1/+0
[ Upstream commit 1b5ba350784242eb1f899bcffd95d2c7cff61e84 ] Arm TC2 fails cpu hotplug stress test. This issue was tracked down to a missing copy of the new affinity cpumask for the vexpress-spc interrupt into struct irq_common_data.affinity when the interrupt is migrated in migrate_one_irq(). Fix it by replacing the arm specific hotplug cpu migration with the generic irq code. This is the counterpart implementation to commit 217d453d473c ("arm64: fix a migrating irq bug when hotplug cpu"). Tested with cpu hotplug stress test on Arm TC2 (multi_v7_defconfig plus CONFIG_ARM_BIG_LITTLE_CPUFREQ=y and CONFIG_ARM_VEXPRESS_SPC_CPUFREQ=y). The vexpress-spc interrupt (irq=22) on this board is affine to CPU0. Its affinity cpumask now changes correctly e.g. from 0 to 1-4 when CPU0 is hotplugged out. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23arm/arm64: KVM: Allow a VCPU to fully reset itselfMarc Zyngier1-0/+10
[ Upstream commit 358b28f09f0ab074d781df72b8a671edb1547789 ] The current kvm_psci_vcpu_on implementation will directly try to manipulate the state of the VCPU to reset it. However, since this is not done on the thread that runs the VCPU, we can end up in a strangely corrupted state when the source and target VCPUs are running at the same time. Fix this by factoring out all reset logic from the PSCI implementation and forwarding the required information along with a request to the target VCPU. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: spectre-v2: per-CPU vtables to work around big.Little systemsRussell King1-0/+23
Commit 383fb3ee8024d596f488d2dbaf45e572897acbdb upstream. In big.Little systems, some CPUs require the Spectre workarounds in paths such as the context switch, but other CPUs do not. In order to handle these differences, we need per-CPU vtables. We are unable to use the kernel's per-CPU variables to support this as per-CPU is not initialised at times when we need access to the vtables, so we have to use an array indexed by logical CPU number. We use an array-of-pointers to avoid having function pointers in the kernel's read/write .data section. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: add PROC_VTABLE and PROC_TABLE macrosRussell King1-13/+26
Commit e209950fdd065d2cc46e6338e47e52841b830cba upstream. Allow the way we access members of the processor vtable to be changed at compile time. We will need to move to per-CPU vtables to fix the Spectre variant 2 issues on big.Little systems. However, we have a couple of calls that do not need the vtable treatment, and indeed cause a kernel warning due to the (later) use of smp_processor_id(), so also introduce the PROC_TABLE macro for these which always use CPU 0's function pointers. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: clean up per-processor check_bugs method callRussell King1-0/+1
Commit 945aceb1db8885d3a35790cf2e810f681db52756 upstream. Call the per-processor type check_bugs() method in the same way as we do other per-processor functions - move the "processor." detail into proc-fns.h. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: split out processor lookupRussell King1-0/+1
Commit 65987a8553061515b5851b472081aedb9837a391 upstream. Split out the lookup of the processor type and associated error handling from the rest of setup_processor() - we will need to use this in the secondary CPU bringup path for big.Little Spectre variant 2 mitigation. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitizationJulien Thierry2-0/+37
Commit afaf6838f4bc896a711180b702b388b8cfa638fc upstream. Introduce C and asm helpers to sanitize user address, taking the address range they target into account. Use asm helper for existing sanitization in __copy_from_user(). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: 8795/1: spectre-v1.1: use put_user() for __put_user()Julien Thierry1-6/+9
Commit e3aa6243434fd9a82e84bb79ab1abd14f2d9a5a7 upstream. When Spectre mitigation is required, __put_user() needs to include check_uaccess. This is already the case for put_user(), so just make __put_user() an alias of put_user(). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limitJulien Thierry1-0/+8
Commit 621afc677465db231662ed126ae1f355bf8eac47 upstream. A mispredicted conditional call to set_fs could result in the wrong addr_limit being forwarded under speculation to a subsequent access_ok check, potentially forming part of a spectre-v1 attack using uaccess routines. This patch prevents this forwarding from taking place, but putting heavy barriers in set_fs after writing the addr_limit. Porting commit c2f0ad4fc089cff8 ("arm64: uaccess: Prevent speculative use of the current addr_limit"). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: 8791/1: vfp: use __copy_to_user() when saving VFP stateJulien Thierry1-2/+2
Commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 upstream. Use __copy_to_user() rather than __put_user_error() for individual members when saving VFP state. This has the benefit of disabling/enabling PAN once per copied struct intead of once per write. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-29mm: make the __PAGETABLE_PxD_FOLDED defines non-emptyMartin Schwidefsky1-1/+1
[ Upstream commit a8874e7e8a8896f2b6c641f4b8e2473eafd35204 ] Change the currently empty defines for __PAGETABLE_PMD_FOLDED, __PAGETABLE_PUD_FOLDED and __PAGETABLE_P4D_FOLDED to return 1. This makes it possible to use __is_defined() to test if the preprocessor define exists. Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-09-07KVM: Remove obsolete kvm_unmap_hva notifier backendMarc Zyngier1-1/+0
kvm_unmap_hva is long gone, and we only have kvm_unmap_hva_range to deal with. Drop the now obsolete code. Fixes: fb1522e099f0 ("KVM: update to new mmu_notifier semantic v2") Cc: James Hogan <jhogan@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2018-08-22Merge tag 'kvmarm-for-v4.19' of ↵Paolo Bonzini3-12/+19
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for 4.19 - Support for Group0 interrupts in guests - Cache management optimizations for ARMv8.4 systems - Userspace interface for RAS, allowing error retrival and injection - Fault path optimization - Emulated physical timer fixes - Random cleanups
2018-08-17Merge tag 'modules-for-v4.19' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull modules updates from Jessica Yu: "Summary of modules changes for the 4.19 merge window: - Fix modules kallsyms for livepatch. Livepatch modules can have SHN_UNDEF symbols in their module symbol tables for later symbol resolution, but kallsyms shouldn't be returning these symbols - Some code cleanups and minor reshuffling in load_module() were done to log the module name when module signature verification fails" * tag 'modules-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: kernel/module: Use kmemdup to replace kmalloc+memcpy ARM: module: fix modsign build error modsign: log module name in the event of an error module: replace VMLINUX_SYMBOL_STR() with __stringify() or string literal module: print sensible error code module: setup load info before module_sig_check() module: make it clear when we're handling the module copy in info->hdr module: exclude SHN_UNDEF symbols from kallsyms api
2018-08-15Merge tag 'arm64-upstream' of ↵Linus Torvalds1-7/+7
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "A bunch of good stuff in here. Worth noting is that we've pulled in the x86/mm branch from -tip so that we can make use of the core ioremap changes which allow us to put down huge mappings in the vmalloc area without screwing up the TLB. Much of the positive diffstat is because of the rseq selftest for arm64. Summary: - Wire up support for qspinlock, replacing our trusty ticket lock code - Add an IPI to flush_icache_range() to ensure that stale instructions fetched into the pipeline are discarded along with the I-cache lines - Support for the GCC "stackleak" plugin - Support for restartable sequences, plus an arm64 port for the selftest - Kexec/kdump support on systems booting with ACPI - Rewrite of our syscall entry code in C, which allows us to zero the GPRs on entry from userspace - Support for chained PMU counters, allowing 64-bit event counters to be constructed on current CPUs - Ensure scheduler topology information is kept up-to-date with CPU hotplug events - Re-enable support for huge vmalloc/IO mappings now that the core code has the correct hooks to use break-before-make sequences - Miscellaneous, non-critical fixes and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (90 commits) arm64: alternative: Use true and false for boolean values arm64: kexec: Add comment to explain use of __flush_icache_range() arm64: sdei: Mark sdei stack helper functions as static arm64, kaslr: export offset in VMCOREINFO ELF notes arm64: perf: Add cap_user_time aarch64 efi/libstub: Only disable stackleak plugin for arm64 arm64: drop unused kernel_neon_begin_partial() macro arm64: kexec: machine_kexec should call __flush_icache_range arm64: svc: Ensure hardirq tracing is updated before return arm64: mm: Export __sync_icache_dcache() for xen-privcmd drivers/perf: arm-ccn: Use devm_ioremap_resource() to map memory arm64: Add support for STACKLEAK gcc plugin arm64: Add stack information to on_accessible_stack drivers/perf: hisi: update the sccl_id/ccl_id when MT is supported arm64: fix ACPI dependencies rseq/selftests: Add support for arm64 arm64: acpi: fix alignment fault in accessing ACPI efi/arm: map UEFI memory map even w/o runtime services enabled efi/arm: preserve early mapping of UEFI memory map longer for BGRT drivers: acpi: add dependency of EFI for arm64 ...
2018-08-14Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds4-92/+34
Pull ARM updates from Russell King: - further Spectre variant 1 fixes for user accessors. - kbuild cleanups (Masahiro Yamada) - hook up sync core functionality (Will Deacon) - nommu updates for hypervisor mode booting (Vladimir Murzin) - use compiler built-ins for fls and ffs (Nicolas Pitre) * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: spectre-v1: mitigate user accesses ARM: spectre-v1: use get_user() for __get_user() ARM: use __inttype() in get_user() ARM: oabi-compat: copy semops using __copy_from_user() ARM: vfp: use __copy_from_user() when restoring VFP state ARM: 8785/1: use compiler built-ins for ffs and fls ARM: 8784/1: NOMMU: Allow enter in Hyp mode ARM: 8783/1: NOMMU: Extend check for VBAR support ARM: 8782/1: vfp: clean up arch/arm/vfp/Makefile ARM: signal: copy registers using __copy_from_user() ARM: tcm: ensure inline stub functions are marked static ARM: 8779/1: add endianness option to LDFLAGS instead of LD ARM: 8777/1: Hook up SYNC_CORE functionality for sys_membarrier()
2018-08-14Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 timer updates from Thomas Gleixner: "Early TSC based time stamping to allow better boot time analysis. This comes with a general cleanup of the TSC calibration code which grew warts and duct taping over the years and removes 250 lines of code. Initiated and mostly implemented by Pavel with help from various folks" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/kvmclock: Mark kvm_get_preset_lpj() as __init x86/tsc: Consolidate init code sched/clock: Disable interrupts when calling generic_sched_clock_init() timekeeping: Prevent false warning when persistent clock is not available sched/clock: Close a hole in sched_clock_init() x86/tsc: Make use of tsc_calibrate_cpu_early() x86/tsc: Split native_calibrate_cpu() into early and late parts sched/clock: Use static key for sched_clock_running sched/clock: Enable sched clock early sched/clock: Move sched clock initialization and merge with generic clock x86/tsc: Use TSC as sched clock early x86/tsc: Initialize cyc2ns when tsc frequency is determined x86/tsc: Calibrate tsc only once ARM/time: Remove read_boot_clock64() s390/time: Remove read_boot_clock64() timekeeping: Default boot time offset to local_clock() timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset() s390/time: Add read_persistent_wall_and_boot_offset() x86/xen/time: Output xen sched_clock time from 0 x86/xen/time: Initialize pv xen time in init_hypervisor_platform() ...
2018-08-14Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Thomas Gleixner: - Make lazy TLB mode even lazier to avoid pointless switch_mm() operations, which reduces CPU load by 1-2% for memcache workloads - Small cleanups and improvements all over the place * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Remove redundant check for kmem_cache_create() arm/asm/tlb.h: Fix build error implicit func declaration x86/mm/tlb: Make clear_asid_other() static x86/mm/tlb: Skip atomic operations for 'init_mm' in switch_mm_irqs_off() x86/mm/tlb: Always use lazy TLB mode x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs x86/mm/tlb: Make lazy TLB mode lazier x86/mm/tlb: Restructure switch_mm_irqs_off() x86/mm/tlb: Leave lazy TLB mode at page table free time mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids x86/mm: Add TLB purge to free pmd/pte page interfaces ioremap: Update pgtable free interfaces with addr x86/mm: Disable ioremap free page handling on x86-PAE
2018-08-13Merge branch 'perf-core-for-linus' of ↵Linus Torvalds3-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf update from Thomas Gleixner: "The perf crowd presents: Kernel updates: - Removal of jprobes - Cleanup and consolidatation the handling of kprobes - Cleanup and consolidation of hardware breakpoints - The usual pile of fixes and updates to PMUs and event descriptors Tooling updates: - Updates and improvements all over the place. Nothing outstanding, just the (good) boring incremental grump work" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits) perf trace: Do not require --no-syscalls to suppress strace like output perf bpf: Include uapi/linux/bpf.h from the 'perf trace' script's bpf.h perf tools: Allow overriding MAX_NR_CPUS at compile time perf bpf: Show better message when failing to load an object perf list: Unify metric group description format with PMU event description perf vendor events arm64: Update ThunderX2 implementation defined pmu core events perf cs-etm: Generate branch sample for CS_ETM_TRACE_ON packet perf cs-etm: Generate branch sample when receiving a CS_ETM_TRACE_ON packet perf cs-etm: Support dummy address value for CS_ETM_TRACE_ON packet perf cs-etm: Fix start tracing packet handling perf build: Fix installation directory for eBPF perf c2c report: Fix crash for empty browser perf tests: Fix indexing when invoking subtests perf trace: Beautify the AF_INET & AF_INET6 'socket' syscall 'protocol' args perf trace beauty: Add beautifiers for 'socket''s 'protocol' arg perf trace beauty: Do not print NULL strarray entries perf beauty: Add a generator for IPPROTO_ socket's protocol constants tools include uapi: Grab a copy of linux/in.h perf tests: Fix complex event name parsing perf evlist: Fix error out while applying initial delay and LBR ...
2018-08-13Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-41/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking/atomics update from Thomas Gleixner: "The locking, atomics and memory model brains delivered: - A larger update to the atomics code which reworks the ordering barriers, consolidates the atomic primitives, provides the new atomic64_fetch_add_unless() primitive and cleans up the include hell. - Simplify cmpxchg() instrumentation and add instrumentation for xchg() and cmpxchg_double(). - Updates to the memory model and documentation" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/atomics: Rework ordering barriers locking/atomics: Instrument cmpxchg_double*() locking/atomics: Instrument xchg() locking/atomics: Simplify cmpxchg() instrumentation locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation tools/memory-model: Rename litmus tests to comply to norm7 tools/memory-model/Documentation: Fix typo, smb->smp sched/Documentation: Update wake_up() & co. memory-barrier guarantees locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock() sched/core: Use smp_mb() in wake_woken_function() tools/memory-model: Add informal LKMM documentation to MAINTAINERS locking/atomics/Documentation: Describe atomic_set() as a write operation tools/memory-model: Make scripts executable tools/memory-model: Remove ACCESS_ONCE() from model tools/memory-model: Remove ACCESS_ONCE() from recipes locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example MAINTAINERS: Add Daniel Lustig as an LKMM reviewer tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name tools/memory-model: Add litmus test for full multicopy atomicity locking/refcount: Always allow checked forms ...
2018-08-13Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull genirq updates from Thomas Gleixner: "The irq departement provides: - A synchronization fix for free_irq() to synchronize just the removed interrupt thread on shared interrupt lines. - Consolidate the multi low level interrupt entry handling and mvoe it to the generic code instead of adding yet another copy for RISC-V - Refactoring of the ARM LPI allocator and LPI exposure to the hypervisor - Yet another interrupt chip driver for the JZ4725B SoC - Speed up for /proc/interrupts as people seem to love reading this file with high frequency - Miscellaneous fixes and updates" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) irqchip/gic-v3-its: Make its_lock a raw_spin_lock_t genirq/irqchip: Remove MULTI_IRQ_HANDLER as it's now obselete openrisc: Use the new GENERIC_IRQ_MULTI_HANDLER arm64: Use the new GENERIC_IRQ_MULTI_HANDLER ARM: Convert to GENERIC_IRQ_MULTI_HANDLER irqchip: Port the ARM IRQ drivers to GENERIC_IRQ_MULTI_HANDLER irqchip/gic-v3-its: Reduce minimum LPI allocation to 1 for PCI devices dt-bindings: irqchip: renesas-irqc: Document r8a77980 support dt-bindings: irqchip: renesas-irqc: Document r8a77470 support irqchip/ingenic: Add support for the JZ4725B SoC irqchip/stm32: Add exti0 translation for stm32mp1 genirq: Remove redundant NULL pointer check in __free_irq() irqchip/gic-v3-its: Honor hypervisor enforced LPI range irqchip/gic-v3: Expose GICD_TYPER in the rdist structure irqchip/gic-v3-its: Drop chunk allocation compatibility irqchip/gic-v3-its: Move minimum LPI requirements to individual busses irqchip/gic-v3-its: Use full range of LPIs irqchip/gic-v3-its: Refactor LPI allocator genirq: Synchronize only with single thread on free_irq() genirq: Update code comments wrt recycled thread_mask ...
2018-08-13Merge branches 'fixes', 'misc' and 'spectre' into for-linusRussell King4-92/+34
Conflicts: arch/arm/include/asm/uaccess.h Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-08-12KVM: arm: Use true and false for boolean valuesGustavo A. R. Silva1-1/+1
Return statements in functions returning bool should use true or false instead of an integer value. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-08-03ARM: Convert to GENERIC_IRQ_MULTI_HANDLERPalmer Dabbelt2-6/+1
Converts the ARM interrupt code to use the recently added GENERIC_IRQ_MULTI_HANDLER, which is essentially just a copy of ARM's existhing MULTI_IRQ_HANDLER. The only changes are: * handle_arch_irq is now defined in a generic C file instead of an arm-specific assembly file. * handle_arch_irq is now marked as __ro_after_init. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux@armlinux.org.uk Cc: catalin.marinas@arm.com Cc: Will Deacon <will.deacon@arm.com> Cc: jonas@southpole.se Cc: stefan.kristiansson@saunalahti.fi Cc: shorne@gmail.com Cc: jason@lakedaemon.net Cc: marc.zyngier@arm.com Cc: Arnd Bergmann <arnd@arndb.de> Cc: nicolas.pitre@linaro.org Cc: vladimir.murzin@arm.com Cc: keescook@chromium.org Cc: jinb.park7@gmail.com Cc: yamada.masahiro@socionext.com Cc: alexandre.belloni@bootlin.com Cc: pombredanne@nexb.com Cc: Greg KH <gregkh@linuxfoundation.org> Cc: kstewart@linuxfoundation.org Cc: jhogan@kernel.org Cc: mark.rutland@arm.com Cc: ard.biesheuvel@linaro.org Cc: james.morse@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: openrisc@lists.librecores.org Link: https://lkml.kernel.org/r/20180622170126.6308-3-palmer@sifive.com
2018-08-02ARM: spectre-v1: mitigate user accessesRussell King1-0/+4
Spectre variant 1 attacks are about this sequence of pseudo-code: index = load(user-manipulated pointer); access(base + index * stride); In order for the cache side-channel to work, the access() must me made to memory which userspace can detect whether cache lines have been loaded. On 32-bit ARM, this must be either user accessible memory, or a kernel mapping of that same user accessible memory. The problem occurs when the load() speculatively loads privileged data, and the subsequent access() is made to user accessible memory. Any load() which makes use of a user-maniplated pointer is a potential problem if the data it has loaded is used in a subsequent access. This also applies for the access() if the data loaded by that access is used by a subsequent access. Harden the get_user() accessors against Spectre attacks by forcing out of bounds addresses to a NULL pointer. This prevents get_user() being used as the load() step above. As a side effect, put_user() will also be affected even though it isn't implicated. Also harden copy_from_user() by redoing the bounds check within the arm_copy_from_user() code, and NULLing the pointer if out of bounds. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-08-02ARM: spectre-v1: use get_user() for __get_user()Russell King1-6/+11
Fixing __get_user() for spectre variant 1 is not sane: we would have to add address space bounds checking in order to validate that the location should be accessed, and then zero the address if found to be invalid. Since __get_user() is supposed to avoid the bounds check, and this is exactly what get_user() does, there's no point having two different implementations that are doing the same thing. So, when the Spectre workarounds are required, make __get_user() an alias of get_user(). Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-08-02ARM: use __inttype() in get_user()Russell King1-1/+8
Borrow the x86 implementation of __inttype() to use in get_user() to select an integer type suitable to temporarily hold the result value. This is necessary to avoid propagating the volatile nature of the result argument, which can cause the following warning: lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var] Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-08-02ARM: vfp: use __copy_from_user() when restoring VFP stateRussell King1-2/+2
__get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Use __copy_from_user() rather than __get_user_err() for individual members when restoring VFP state. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-07-30ARM: 8785/1: use compiler built-ins for ffs and flsNicolas Pitre1-83/+9
On ARMv5 and above, it is beneficial to use compiler built-ins such as __builtin_ffs() and __builtin_ctzl() to implement ffs(), __ffs(), fls() and __fls(). The compiler does inline the clz instruction and even the rbit instruction when available, or provide a constant value when possible. On ARMv4 the compiler calls out to helper functions for those built-ins so it is best to keep the open coded versions in that case. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-07-25arm/asm/tlb.h: Fix build error implicit func declarationAnders Roxell1-0/+8
Building on arm 32 with LPAE enabled we don't include asm-generic/tlb.h, where we have tlb_flush_remove_tables_local and tlb_flush_remove_tables defined. The build fails with: mm/memory.c: In function ‘tlb_remove_table_smp_sync’: mm/memory.c:339:2: error: implicit declaration of function ‘tlb_flush_remove_tables_local’; did you mean ‘tlb_remove_table’? [-Werror=implicit-function-declaration] ... This bug got introduced in: 2ff6ddf19c0e ("x86/mm/tlb: Leave lazy TLB mode at page table free time") To fix this issue we define them in arm 32's specific asm/tlb.h file as well. Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave.hansen@intel.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux@armlinux.org.uk Cc: riel@surriel.com Cc: songliubraving@fb.com Fixes: 2ff6ddf19c0e ("x86/mm/tlb: Leave lazy TLB mode at page table free time") Link: http://lkml.kernel.org/r/20180725095557.19668-1-anders.roxell@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi: Deduplicate efi_open_volume()Lukas Wunner1-0/+3
There's one ARM, one x86_32 and one x86_64 version of efi_open_volume() which can be folded into a single shared version by masking their differences with the efi_call_proto() macro introduced by commit: 3552fdf29f01 ("efi: Allow bitness-agnostic protocol calls"). To be able to dereference the device_handle attribute from the efi_loaded_image_t table in an arch- and bitness-agnostic manner, introduce the efi_table_attr() macro (which already exists for x86) to arm and arm64. No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-21KVM: arm: Add 32bit get/set events supportJames Morse1-0/+5
arm64's new use of KVMs get_events/set_events API calls isn't just or RAS, it allows an SError that has been made pending by KVM as part of its device emulation to be migrated. Wire this up for 32bit too. We only need to read/write the HCR_VA bit, and check that no esr has been provided, as we don't yet support VDFSR. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Dongjiu Geng <gengdongjiu@huawei.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-20ARM/time: Remove read_boot_clock64()Pavel Tatashin1-2/+1
read_boot_clock64() is deleted, and replaced with read_persistent_wall_and_boot_offset(). The default implementation of read_persistent_wall_and_boot_offset() provides a better fallback than the current stubs for read_boot_clock64() that arm has with no users, so remove the old code. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-19-pasha.tatashin@oracle.com
2018-07-09ARM: module: fix modsign build errorArnd Bergmann1-0/+1
The asm/module.h header file can not be included standalone, which breaks the module signing code after a recent change: In file included from kernel/module-internal.h:13, from kernel/module_signing.c:17: arch/arm/include/asm/module.h:37:27: error: 'struct module' declared inside parameter list will not be visible outside of this definition or declaration [-Werror] u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val); This adds a forward declaration of struct module to make it all work. Fixes: f314dfea16a0 ("modsign: log module name in the event of an error") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-07-09KVM: arm/arm64: Enable adaptative WFE trappingMarc Zyngier1-0/+10
Trapping blocking WFE is extremely beneficial in situations where the system is oversubscribed, as it allows another thread to run while being blocked. In a non-oversubscribed environment, this is the complete opposite, and trapping WFE is just unnecessary overhead. Let's only enable WFE trapping if the CPU has more than a single task to run (that is, more than just the vcpu thread). Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-09KVM: arm/arm64: Stop using the kernel's {pmd,pud,pgd}_populate helpersMarc Zyngier1-0/+4
The {pmd,pud,pgd}_populate accessors usage have always been a bit weird in KVM. We don't have a struct mm to pass (and neither does the kernel most of the time, but still...), and the 32bit code has all kind of cache maintenance that doesn't make sense on ARMv7+ when MP extensions are mandatory (which is the case when the VEs are present). Let's bite the bullet and provide our own implementations. The only bit of architectural code left has to do with building the table entry itself (arm64 having up to 52bit PA, arm lacking PUD level). Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-09KVM: arm/arm64: Consolidate page-table accessorsMarc Zyngier1-12/+0
The arm and arm64 KVM page tables accessors are pointlessly different between the two architectures, and likely both wrong one way or another: arm64 lacks a dsb(), and arm doesn't use WRITE_ONCE. Let's unify them. Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-05kvm/arm: use PSR_AA32 definitionsMark Rutland1-7/+7
Some code cares about the SPSR_ELx format for exceptions taken from AArch32 to inspect or manipulate the SPSR_ELx value, which is already in the SPSR_ELx format, and not in the AArch32 PSR format. To separate these from cases where we care about the AArch32 PSR format, migrate these cases to use the PSR_AA32_* definitions rather than COMPAT_PSR_*. There should be no functional change as a result of this patch. Note that arm64 KVM does not support a compat KVM API, and always uses the SPSR_ELx format, even for AArch32 guests. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-06-26perf/hw_breakpoint: Remove default hw_breakpoint_arch_parse()Frederic Weisbecker1-1/+0
All architectures have implemented it, we can now remove the poor weak version. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joel Fernandes <joel.opensrc@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/1529981939-8231-11-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-26perf/arch/arm: Implement hw_breakpoint_arch_parse()Frederic Weisbecker1-1/+5
Migrate to the new API in order to remove arch_validate_hwbkpt_settings() that clumsily mixes up architecture validation and commit. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joel Fernandes <joel.opensrc@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/1529981939-8231-6-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-26perf/hw_breakpoint: Pass arch breakpoint struct to ↵Frederic Weisbecker1-1/+1
arch_check_bp_in_kernelspace() We can't pass the breakpoint directly on arch_check_bp_in_kernelspace() anymore because its architecture internal datas (struct arch_hw_breakpoint) are not yet filled by the time we call the function, and most implementation need this backend to be up to date. So arrange the function to take the probing struct instead. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joel Fernandes <joel.opensrc@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/1529981939-8231-3-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Clean up '*_andnot()' ifdefferyMark Rutland1-0/+2
The ifdeffery for atomic*_{fetch_,}andnot() is unlike that for all the other atomics. If atomic*_andnot() is not defined, the corresponding atomic*_fetch_andnot() is assumed to not be defined. Additionally, the fallbacks for the various ordering cases are written much later in atomic.h as static inlines. This isn't problematic today, but gets in the way of scripting the generation of atomics. To prepare for scripting, this patch: * Switches to separate ifdefs for atomic*_andnot() and atomic*_fetch_andnot(), updating implementations as appropriate. * Moves the fallbacks into the standards ifdefs, as macro expansions rather than static inlines. * Removes trivial andnot implementations from architectures, where these are superseded by core code. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-19-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make conditional inc/dec ops optionalMark Rutland1-0/+1
The conditional inc/dec ops differ for atomic_t and atomic64_t: - atomic_inc_unless_positive() is optional for atomic_t, and doesn't exist for atomic64_t. - atomic_dec_unless_negative() is optional for atomic_t, and doesn't exist for atomic64_t. - atomic_dec_if_positive is optional for atomic_t, and is mandatory for atomic64_t. Let's make these consistently optional for both. At the same time, let's clean up the existing fallbacks to use atomic_try_cmpxchg(). The instrumented atomics are updated accordingly. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-18-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make unconditional inc/dec ops optionalMark Rutland1-11/+0
Many of the inc/dec ops are mandatory, but for most architectures inc/dec are simply trivial wrappers around their corresponding add/sub ops. Let's make all the inc/dec ops optional, so that we can get rid of these boilerplate wrappers. The instrumented atomics are updated accordingly. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-17-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make test ops optionalMark Rutland1-9/+0
Some of the atomics return the result of a test applied after the atomic operation, and almost all architectures implement these as trivial wrappers around the underlying atomic. Specifically: * <atomic>_inc_and_test(v) is (<atomic>_inc_return(v) == 0) * <atomic>_dec_and_test(v) is (<atomic>_dec_return(v) == 0) * <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0) * <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v) < 0) Rather than have these definitions duplicated in all architectures, with minor inconsistencies in formatting and documentation, let's make these operations optional, with default fallbacks as above. Implementations must now provide a preprocessor symbol. The instrumented atomics are updated accordingly. Both x86 and m68k have custom implementations, which are left as-is, given preprocessor symbols to avoid being overridden. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-16-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/arm: Define atomic64_fetch_add_unless()Mark Rutland1-10/+10
As a step towards unifying the atomic/atomic64/atomic_long APIs, this patch converts the arch/arm implementation of atomic64_add_unless() into an implementation of atomic64_fetch_add_unless(). A wrapper in <linux/atomic.h> will build atomic_add_unless() atop of this, provided it is given a preprocessor definition. No functional change is intended as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-12-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make atomic_fetch_add_unless() optionalMark Rutland1-10/+1
Several architectures these have a near-identical implementation based on atomic_read() and atomic_cmpxchg() which we can instead define in <linux/atomic.h>, so let's do so, using something close to the existing x86 implementation with try_cmpxchg(). Where an architecture provides its own atomic_fetch_add_unless(), it must define a preprocessor symbol for it. The instrumented atomics are updated accordingly. Note that arch/arc's existing atomic_fetch_add_unless() had redundant barriers, as these are already present in its atomic_cmpxchg() implementation. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make atomic64_inc_not_zero() optionalMark Rutland1-1/+0
We define a trivial fallback for atomic_inc_not_zero(), but don't do the same for atomic64_inc_not_zero(), leading most architectures to define the same boilerplate. Let's add a fallback in <linux/atomic.h>, and remove the redundant implementations. Note that atomic64_add_unless() is always defined in <linux/atomic.h>, and promotes its arguments to the requisite types, so we need not do this explicitly. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-6-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>