summaryrefslogtreecommitdiff
path: root/arch/s390/include
Commit message (Collapse)AuthorAge
...
* | Merge tag 'locks-v4.15-1' of ↵Linus Torvalds2017-11-17
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull file locking update from Jeff Layton: "A couple of fixes for a patch that went into v4.14, and the bug report just came in a few days ago.. It passes my (minimal) testing, and has been in linux-next for a few days now. I also would like to get my address changed in MAINTAINERS to clear that hurdle" * tag 'locks-v4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: fcntl: don't cap l_start and l_end values for F_GETLK64 in compat syscall fcntl: don't leak fd reference when fixup_compat_flock fails MAINTAINERS: s/jlayton@poochiereds.net/jlayton@kernel.org/
| * | fcntl: don't cap l_start and l_end values for F_GETLK64 in compat syscallJeff Layton2017-11-15
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we're capping the values too low in the F_GETLK64 case. The fields in that structure are 64-bit values, so we shouldn't need to do any sort of fixup there. Make sure we check that assumption at build time in the future however by ensuring that the sizes we're copying will fit. With this, we no longer need COMPAT_LOFF_T_MAX either, so remove it. Fixes: 94073ad77fff2 (fs/locks: don't mess with the address limit in compat_fcntl64) Reported-by: Vitaly Lipatov <lav@etersoft.ru> Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com>
* | Merge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2017-11-16
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM updates from Radim Krčmář: "First batch of KVM changes for 4.15 Common: - Python 3 support in kvm_stat - Accounting of slabs to kmemcg ARM: - Optimized arch timer handling for KVM/ARM - Improvements to the VGIC ITS code and introduction of an ITS reset ioctl - Unification of the 32-bit fault injection logic - More exact external abort matching logic PPC: - Support for running hashed page table (HPT) MMU mode on a host that is using the radix MMU mode; single threaded mode on POWER 9 is added as a pre-requisite - Resolution of merge conflicts with the last second 4.14 HPT fixes - Fixes and cleanups s390: - Some initial preparation patches for exitless interrupts and crypto - New capability for AIS migration - Fixes x86: - Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs, and after-reset state - Refined dependencies for VMX features - Fixes for nested SMI injection - A lot of cleanups" * tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (89 commits) KVM: s390: provide a capability for AIS state migration KVM: s390: clear_io_irq() requests are not expected for adapter interrupts KVM: s390: abstract conversion between isc and enum irq_types KVM: s390: vsie: use common code functions for pinning KVM: s390: SIE considerations for AP Queue virtualization KVM: s390: document memory ordering for kvm_s390_vcpu_wakeup KVM: PPC: Book3S HV: Cosmetic post-merge cleanups KVM: arm/arm64: fix the incompatible matching for external abort KVM: arm/arm64: Unify 32bit fault injection KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared KVM: arm/arm64: vgic-its: New helper functions to free the caches KVM: arm/arm64: vgic-its: Remove kvm_its_unmap_device arm/arm64: KVM: Load the timer state when enabling the timer KVM: arm/arm64: Rework kvm_timer_should_fire KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit KVM: arm/arm64: Move phys_timer_emulate function KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps ...
| * \ Merge tag 'kvm-s390-next-4.15-1' of ↵Radim Krčmář2017-11-16
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux KVM: s390: fixes and improvements for 4.15 - Some initial preparation patches for exitless interrupts and crypto - New capability for AIS migration - Fixes - merge of the sthyi tree from the base s390 team, which moves the sthyi out of KVM into a shared function also for non-KVM
| | * | KVM: s390: SIE considerations for AP Queue virtualizationTony Krowiak2017-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Crypto Control Block (CRYCB) is referenced by the SIE state description and controls KVM guest access to the Adjunct Processor (AP) adapters, usage domains and control domains. This patch defines the AP control blocks to be used for controlling guest access to the AP adapters and domains. Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com> Message-Id: <1507916344-3896-2-git-send-email-akrowiak@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* | | | mm: account pud page tablesKirill A. Shutemov2017-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a machine with 5-level paging support a process can allocate significant amount of memory and stay unnoticed by oom-killer and memory cgroup. The trick is to allocate a lot of PUD page tables. We don't account PUD page tables, only PMD and PTE. We already addressed the same issue for PMD page tables, see commit dc6c9a35b66b ("mm: account pmd page tables to the process"). Introduction of 5-level paging brings the same issue for PUD page tables. The patch expands accounting to PUD level. [kirill.shutemov@linux.intel.com: s/pmd_t/pud_t/] Link: http://lkml.kernel.org/r/20171004074305.x35eh5u7ybbt5kar@black.fi.intel.com [heiko.carstens@de.ibm.com: s390/mm: fix pud table accounting] Link: http://lkml.kernel.org/r/20171103090551.18231-1-heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20171002080427.3320-1-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2017-11-14
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull dma-mapping updates from Christoph Hellwig: - turn dma_cache_sync into a dma_map_ops instance and remove implementation that purely are dead because the architecture doesn't support noncoherent allocations - add a flag for busses that need DMA configuration (Robin Murphy) * tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mapping: dma-mapping: turn dma_cache_sync into a dma_map_ops method sh: make dma_cache_sync a no-op xtensa: make dma_cache_sync a no-op unicore32: make dma_cache_sync a no-op powerpc: make dma_cache_sync a no-op mn10300: make dma_cache_sync a no-op microblaze: make dma_cache_sync a no-op ia64: make dma_cache_sync a no-op frv: make dma_cache_sync a no-op x86: make dma_cache_sync a no-op floppy: consolidate the dummy fd_cacheflush definition drivers: flag buses which demand DMA configuration
| * | | dma-mapping: turn dma_cache_sync into a dma_map_ops methodChristoph Hellwig2017-10-19
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After we removed all the dead wood it turns out only two architectures actually implement dma_cache_sync as a real op: mips and parisc. Add a cache_sync method to struct dma_map_ops and implement it for the mips defualt DMA ops, and the parisc pa11 ops. Note that arm, arc and openrisc support DMA_ATTR_NON_CONSISTENT, but never provided a functional dma_cache_sync implementations, which seems somewhat odd. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
* | | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2017-11-13
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core locking updates from Ingo Molnar: "The main changes in this cycle are: - Another attempt at enabling cross-release lockdep dependency tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time with better performance and fewer false positives. (Byungchul Park) - Introduce lockdep_assert_irqs_enabled()/disabled() and convert open-coded equivalents to lockdep variants. (Frederic Weisbecker) - Add down_read_killable() and use it in the VFS's iterate_dir() method. (Kirill Tkhai) - Convert remaining uses of ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle driven. (Mark Rutland, Paul E. McKenney) - Get rid of lockless_dereference(), by strengthening Alpha atomics, strengthening READ_ONCE() with smp_read_barrier_depends() and thus being able to convert users of lockless_dereference() to READ_ONCE(). (Will Deacon) - Various micro-optimizations: - better PV qspinlocks (Waiman Long), - better x86 barriers (Michael S. Tsirkin) - better x86 refcounts (Kees Cook) - ... plus other fixes and enhancements. (Borislav Petkov, Juergen Gross, Miguel Bernal Marin)" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE rcu: Use lockdep to assert IRQs are disabled/enabled netpoll: Use lockdep to assert IRQs are disabled/enabled timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled irq_work: Use lockdep to assert IRQs are disabled/enabled irq/timings: Use lockdep to assert IRQs are disabled/enabled perf/core: Use lockdep to assert IRQs are disabled/enabled x86: Use lockdep to assert IRQs are disabled/enabled smp/core: Use lockdep to assert IRQs are disabled/enabled timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled timers/nohz: Use lockdep to assert IRQs are disabled/enabled workqueue: Use lockdep to assert IRQs are disabled/enabled irq/softirqs: Use lockdep to assert IRQs are disabled/enabled locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled() locking/pvqspinlock: Implement hybrid PV queued/unfair locks locking/rwlocks: Fix comments x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion() workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes ...
| * \ \ Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar2017-11-07
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland2017-10-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementationsWill Deacon2017-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arch_{read,spin,write}_lock_flags() macros are simply mapped to the non-flags versions by the majority of architectures, so do this in core code and remove the dummy implementations. Also remove the implementation in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call local_irq_save(flags) anyway. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | locking/arch: Remove dummy arch_{read,spin,write}_relax() implementationsWill Deacon2017-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_{read,spin,write}_relax() are defined as cpu_relax() by the core code, so architectures that can't do better (i.e. most of them) don't need to bother with the dummy definitions. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | locking/core: Remove {read,spin,write}_can_lock()Will Deacon2017-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Outside of the locking code itself, {read,spin,write}_can_lock() have no users in tree. Apparmor (the last remaining user of write_can_lock()) got moved over to lockdep by the previous patch. This patch removes the use of {read,spin,write}_can_lock() from the BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the lock status, and subsequently removes the unused macros altogether. They aren't guaranteed to work in a concurrent environment and can give incorrect results in the case of qrwlock. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | locking/arch, s390: Add __down_read_killable()Kirill Tkhai2017-10-10
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to __down_write_killable(), and read killable primitive. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670117817.23930.13068785028558453848.stgit@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'for-linus' of ↵Linus Torvalds2017-11-13
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request for the v4.15 merge window this time from me. Besides a lot of cleanups and bug fixes these are the most important changes: - a new regset for runtime instrumentation registers - hardware accelerated AES-GCM support for the aes_s390 module - support for the new CEX6S crypto cards - support for FORTIFY_SOURCE - addition of missing z13 and new z14 instructions to the in-kernel disassembler - generate opcode tables for the in-kernel disassembler out of a simple text file instead of having to manually maintain those tables - fast memset16, memset32 and memset64 implementations - removal of named saved segment support - hardware counter support for z14 - queued spinlocks and queued rwlocks implementations for s390 - use the stack_depth tracking feature for s390 BPF JIT - a new s390_sthyi system call which emulates the sthyi (store hypervisor information) instruction - removal of the old KVM virtio transport - an s390 specific CPU alternatives implementation which is used in the new spinlock code" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (88 commits) MAINTAINERS: add virtio-ccw.h to virtio/s390 section s390/noexec: execute kexec datamover without DAT s390: fix transactional execution control register handling s390/bpf: take advantage of stack_depth tracking s390: simplify transactional execution elf hwcap handling s390/zcrypt: Rework struct ap_qact_ap_info. s390/virtio: remove unused header file kvm_virtio.h s390: avoid undefined behaviour s390/disassembler: generate opcode tables from text file s390/disassembler: remove insn_to_mnemonic() s390/dasd: avoid calling do_gettimeofday() s390: vfio-ccw: Do not attempt to free no-op, test and tic cda. s390: remove named saved segment support s390/archrandom: Reconsider s390 arch random implementation s390/pci: do not require AIS facility s390/qdio: sanitize put_indicator s390/qdio: use atomic_cmpxchg s390/nmi: avoid using long-displacement facility s390: pass endianness info to sparse s390/decompressor: remove informational messages ...
| * | | s390: fix transactional execution control register handlingHeiko Carstens2017-11-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dan Horák reported the following crash related to transactional execution: User process fault: interruption code 0013 ilc:3 in libpthread-2.26.so[3ff93c00000+1b000] CPU: 2 PID: 1 Comm: /init Not tainted 4.13.4-300.fc27.s390x #1 Hardware name: IBM 2827 H43 400 (z/VM 6.4.0) task: 00000000fafc8000 task.stack: 00000000fafc4000 User PSW : 0705200180000000 000003ff93c14e70 R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:2 PM:0 RI:0 EA:3 User GPRS: 0000000000000077 000003ff00000000 000003ff93144d48 000003ff93144d5e 0000000000000000 0000000000000002 0000000000000000 000003ff00000000 0000000000000000 0000000000000418 0000000000000000 000003ffcc9fe770 000003ff93d28f50 000003ff9310acf0 000003ff92b0319a 000003ffcc9fe6d0 User Code: 000003ff93c14e62: 60e0b030 std %f14,48(%r11) 000003ff93c14e66: 60f0b038 std %f15,56(%r11) #000003ff93c14e6a: e5600000ff0e tbegin 0,65294 >000003ff93c14e70: a7740006 brc 7,3ff93c14e7c 000003ff93c14e74: a7080000 lhi %r0,0 000003ff93c14e78: a7f40023 brc 15,3ff93c14ebe 000003ff93c14e7c: b2220000 ipm %r0 000003ff93c14e80: 8800001c srl %r0,28 There are several bugs with control register handling with respect to transactional execution: - on task switch update_per_regs() is only called if the next task has an mm (is not a kernel thread). This however is incorrect. This breaks e.g. for user mode helper handling, where the kernel creates a kernel thread and then execve's a user space program. Control register contents related to transactional execution won't be updated on execve. If the previous task ran with transactional execution disabled then the new task will also run with transactional execution disabled, which is incorrect. Therefore call update_per_regs() unconditionally within switch_to(). - on startup the transactional execution facility is not enabled for the idle thread. This is not really a bug, but an inconsistency to other facilities. Therefore enable the facility if it is available. - on fork the new thread's per_flags field is not cleared. This means that a child process inherits the PER_FLAG_NO_TE flag. This flag can be set with a ptrace request to disable transactional execution for the current process. It should not be inherited by new child processes in order to be consistent with the handling of all other PER related debugging options. Therefore clear the per_flags field in copy_thread_tls(). Reported-and-tested-by: Dan Horák <dan@danny.cz> Fixes: d35339a42dd1 ("s390: add support for transactional memory") Cc: <stable@vger.kernel.org> # v3.7+ Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390/virtio: remove unused header file kvm_virtio.hChristian Borntraeger2017-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With commit 7fb2b2d51244 ("s390/virtio: remove the old KVM virtio transport") the pre-ccw virtio transport for s390 was removed. To complete the removal the uapi header file that contains the related data structures must also be removed. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390/disassembler: generate opcode tables from text fileHeiko Carstens2017-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current way of adding new instructions to the opcode tables is painful and error prone. Therefore add, similar to binutils, a text file which contains all opcodes and the corresponding mnemonics and instruction formats. A small gen_opcode_table tool then generates a header file with the required enums and opcode table initializers at the prepare step of the kernel build. This way only a simple text file has to be maintained, which can be rather easily extended. Unlike before where there were plenty of opcode tables and a large switch statement to find the correct opcode table, there is now only one opcode table left which contains all instructions. A second opcode offset table now contains offsets within the opcode table to find instructions which have the same opcode prefix. In order to save space all 1-byte opcode instructions are grouped together at the end of the opcode table. This is also quite similar to like it was before. In addition also move and change code and definitions within the disassembler. As a side effect this reduces the size required for the code and opcode tables by ~1.5k. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390/disassembler: remove insn_to_mnemonic()Heiko Carstens2017-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | insn_to_mnemonic() was introduced ages ago for KVM debugging, but is unused in the meantime. Therefore remove it. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390: remove named saved segment supportHeiko Carstens2017-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the support to create a z/VM named saved segment (NSS). This feature is not supported since quite a while in favour of jump labels, function tracing and (now) CPU alternatives. All of these features require to write to the kernel text section which is not possible if the kernel is contained within an NSS. Given that memory savings are minimal if kernel images are shared and in addition updates of shared images are painful, the NSS feature can be removed. Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390/archrandom: Reconsider s390 arch random implementationHarald Freudenberger2017-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reworked version of the random device driver now calls the arch_get_random_* functions on a very high frequency. It does about 100.000 calls to arch_get_random_long for providing 10 MB via /dev/urandom. Each invocation was fetching entropy from the hardware random generator which has a rate limit of about 4 MB/s. As the trng invocation waits until enough entropy is gathered, the random device driver is slowed down dramatically. The s390 true random generator is not designed for such a high rate. The TRNG is more designed to be used together with the arch_get_random_seed_* functions. This is similar to the way how powerpc has implemented their arch random functionality. This patch removes the invocations of the s390 TRNG for arch_get_random_long() and arch_get_random_int() but leaving the invocations for arch_get_random_seed_long() and arch_get_random_seed_int(). So the s390 arch random implementation now contributes high quality entropy to the kernel random device for reseeding. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390/pci: do not require AIS facilityChristian Borntraeger2017-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of today QEMU does not provide the AIS facility to its guest. This prevents Linux guests from using PCI devices as the ais facility is checked during init. As this is just a performance optimization, we can move the ais check into the code where we need it (calling the SIC instruction). This is used at initialization and on interrupt. Both places do not require any serialization, so we can simply skip the instruction. Since we will now get all interrupts, we can also avoid the 2nd scan. As we can have multiple interrupts in parallel we might trigger spurious irqs more often for the non-AIS case but the core code can handle that. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com> Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * | | s390/nmi: do register validation as early as possibleMartin Schwidefsky2017-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The validation of the CPU registers in the machine check handler is currently split into two parts. The first part is done at the start of the low level mcck_int_handler function, this includes the CPU timer register and the general purpose registers. The second part is done a bit later in s390_do_machine_check for all the other registers, including the control registers, floating pointer control, vector or floating pointer registers, the access registers, the guarded storage registers, the TOD programmable registers and the clock comparator. This is working fine to far but in theory a future extensions could cause the C code to use registers that are not validated yet. A better approach is to validate all CPU registers in "safe" assembler code before any C function is called. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/nmi: allocation of the extended save areaMartin Schwidefsky2017-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The machine check extended save area is needed to store the vector registers and the guarded storage control block when a CPU is interrupted by a machine check. Move the slab cache allocation of the full save area to nmi.c, for early boot use a static __initdata block. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/ctl_reg: move control register definitions to ctl_reg.hMartin Schwidefsky2017-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The nmi.h header has some constant defines for control register bits. These definitions should really be located in ctl_reg.h. Move and rename the defines. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/ctl_reg: use decoding unions in update_cr_regsMartin Schwidefsky2017-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a decoding union for the bits in control registers 2 and use 'union ctlreg0' and 'union ctlreg2' in update_cr_regs to improve readability. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/nmi: use smp_emergency_stop instead of smp_send_stopMartin Schwidefsky2017-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The smp_send_stop() function can be called from s390_handle_damage while DAT is off. This happens if a machine check indicates that kernel gprs or control registers can not be restored. The function smp_send_stop reenables DAT via __load_psw_mask. That should work for the case of lost kernel gprs and the system will do the expected stop of all CPUs. But if control registers are lost, in particular CR13 with the home space ASCE, interesting secondary crashes may occur. Make smp_emergency_stop callable from nmi.c and remove the cpumask argument. Replace the smp_send_stop call with smp_emergency_stop in the s390_handle_damage function. In addition add notrace and NOKPROBE_SYMBOL annotations for all functions required for the emergency shutdown. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/vdso: move boot_vdso_data to vdso.cMartin Schwidefsky2017-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The boot_vdso_data variable is related to the vdso code, the magic of the initial vdso area for the early boot and the replacement of it in vdso_init should all be put into vdso.c. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/spinlock: use cpu alternatives to enable niai instructionVasily Gorbik2017-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable niai instruction in the spinlock code at run-time for machines on which facility 49 is available (zEC12 and newer). Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390: introduce CPU alternativesVasily Gorbik2017-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement CPU alternatives, which allows to optionally patch newer instructions at runtime, based on CPU facilities availability. A new kernel boot parameter "noaltinstr" disables patching. Current implementation is derived from x86 alternatives. Although ideal instructions padding (when altinstr is longer then oldinstr) is added at compile time, and no oldinstr nops optimization has to be done at runtime. Also couple of compile time sanity checks are done: 1. oldinstr and altinstr must be <= 254 bytes long, 2. oldinstr and altinstr must not have an odd length. alternative(oldinstr, altinstr, facility); alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2); Both compile time and runtime padding consists of either 6/4/2 bytes nop or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes. .altinstructions and .altinstr_replacement sections are part of __init_begin : __init_end region and are freed after initialization. Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/debug: improve debug_eventSebastian Ott2017-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | debug_event currently truncates the data if used with a size larger than the buf_size of the debug feature. For lots of callers of this function, wrappers have been implemented that loop until all data is handled. Move that functionality into debug_event_common and get rid of the wrappers. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/debug: adjust coding styleHeiko Carstens2017-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The debug feature code hasn't been touched in ages and the code also looks like this. Therefore clean up the code so it looks a bit more like current coding style. There is no functional change - actually I made also sure that the generated code with performance_defconfig is identical. A diff of old vs new with "objdump -d" is empty. The code is still not checkpatch clean, but that was not the goal. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/kprobes: remove KPROBE_SWAP_INST stateHeiko Carstens2017-10-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For an unknown reason the s390 kprobes instruction replacement function modifies the kprobe_status of the current CPU to KPROBE_SWAP_INST. This was supposed to catch traps that happened during instruction patching. Such a fault is not supposed to happen, and silently discarding such a fault is certainly also not what we want. In fact s390 is the only architecture which has this odd piece of code. Just remove this and behave like all other architectures. This was pointed out by Jens Remus. Reported-by: Jens Remus <jremus@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390: cleanup string ops prototypesHeiko Carstens2017-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just some trivial changes like removing the extern keyword from the header file, renaming arguments to match the man pages, and whitespace removal. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/mm: use memset64 instead of clear_tableHeiko Carstens2017-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use memset64 instead of the (now) open-coded variant clear_table. Performance wise there is no difference. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390: implement memset16, memset32 & memset64Heiko Carstens2017-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide fast versions of the new memset variants. E.g. the generic memset64 is ten times slower than the optimized version if used on a whole page. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | Merge branch 'sthyi' into featuresMartin Schwidefsky2017-10-09
| |\ \ \ | | | |/ | | |/| | | | | | | | | Add the store-hypervisor-information code into features using a tip branch for parallel merging into the KVM tree.
| | * | s390/sthyi: add s390_sthyi system callQingFeng Hao2017-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a syscall of s390_sthyi to implement STHYI instruction in LPAR which reuses the implementation for KVM by Janosch Frank - commit 95ca2cb57985 ("KVM: s390: Add sthyi emulation"). STHYI(Store Hypervisor Information) is an emulated z/VM instruction that provides a guest with basic information about the layers it is running on. This includes information about the cpu configuration of both the machine and the lpar, as well as their names, machine model and machine type. This information enables an application to determine the maximum capacity of CPs and IFLs available to software. For the arguments of s390_sthyi, code shall be 0 and flags is reserved for future use, info is the output argument to store the required hypervisor info. Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| | * | s390/sthyi: add cache to store hypervisor infoQingFeng Hao2017-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | STHYI requires extensive locking in the higher hypervisors and is very computational/memory expensive. Therefore we cache the retrieved hypervisor info whose valid period is 1s with mutex to allow concurrent access. rw semaphore can't benefit here due to cache line bounce. Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| | * | s390/sthyi: reorganize sthyi implementationQingFeng Hao2017-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we need to support sthyi instruction on LPAR too, move the common code to kernel part and kvm related code to intercept.c for better reuse. Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390: use generic rwsem implementationHeiko Carstens2017-10-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We never optimized our rwsem inline assemblies to make use of the new atomic instructions. The generic rwsem implementation implicitly makes use of the new instructions, since it implements the required rwsem primitives with atomic operations, which we did optimize. However even when compiling for old architectures the generic variant still generates better code. So it's time to simply remove our old code and switch to the generic implementation. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/ccwgroup: tie a ccwgroup driver to its ccw driverJulian Wiedmann2017-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When grouping devices, the ccwgroup core only checks whether all of the devices are bound to the same ccw_driver. It has no means of checking if the requesting ccwgroup driver actually supports this device type. qeth implements its own device matching in qeth_core_probe_device(), while ctcm and lcs currently have no sanity-checking at all. Enable ccwgroup drivers to optionally defer the device type checking to the ccwgroup core, by specifying their supported ccw_driver. This allows us drop the device type matching from qeth, and improves the robustness of ctcm and lcs. Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com> Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/crypto: add inline assembly for KMA instruction to cpacf.hPatrick Steuer2017-09-29
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Patrick Steuer <patrick.steuer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/rwlock: introduce rwlock wait queueingMartin Schwidefsky2017-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like the common queued rwlock code the s390 implementation uses the queued spinlock code on a spinlock_t embedded in the rwlock_t to achieve the queueing. The encoding of the rwlock_t differs though, the counter field in the rwlock_t is split into two parts. The upper two bytes hold the write bit and the write wait counter, the lower two bytes hold the read counter. The arch_read_lock operation works exactly like the common qrwlock but the enqueue operation for a writer follows a diffent logic. After the failed inline try to get the rwlock in write, the writer first increases the write wait counter, acquires the wait spin_lock for the queueing, and then loops until there are no readers and the write bit is zero. Without the write wait counter a CPU that just released the rwlock could immediately reacquire the lock in the inline code, bypassing all outstanding read and write waiters. For s390 this would cause massive imbalances in favour of writers in case of a contended rwlock. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/spinlock: introduce spinlock wait queueingMartin Schwidefsky2017-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The queued spinlock code for s390 follows the principles of the common code qspinlock implementation but with a few notable differences. The format of the spinlock_t locking word differs, s390 needs to store the logical CPU number of the lock holder in the spinlock_t to be able to use the diagnose 9c directed yield hypervisor call. The inline code sequences for spin_lock and spin_unlock are nice and short. The inline portion of a spin_lock now typically looks like this: lhi %r0,0 # 0 indicates an empty lock l %r1,0x3a0 # CPU number + 1 from lowcore cs %r0,%r1,<some_lock> # lock operation jnz call_wait # on failure call wait function locked: ... call_wait: la %r2,<some_lock> brasl %r14,arch_spin_lock_wait j locked A spin_unlock is as simple as before: lhi %r0,0 sth %r0,2(%r2) # unlock operation After a CPU has queued itself it may not enable interrupts again for the arch_spin_lock_flags() variant. The arch_spin_lock_wait_flags wait function is removed. To improve performance the code implements opportunistic lock stealing. If the wait function finds a spinlock_t that indicates that the lock is free but there are queued waiters, the CPU may steal the lock up to three times without queueing itself. The lock stealing update the steal counter in the lock word to prevent more than 3 steals. The counter is reset at the time the CPU next in the queue successfully takes the lock. While the queued spinlocks improve performance in a system with dedicated CPUs, in a virtualized environment with continuously overcommitted CPUs the queued spinlocks can have a negative effect on performance. This is due to the fact that a queued CPU that is preempted by the hypervisor will block the queue at some point even without holding the lock. With the classic spinlock it does not matter if a CPU is preempted that waits for the lock. Therefore use the queued spinlock code only if the system runs with dedicated CPUs and fall back to classic spinlocks when running with shared CPUs. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/spinlock: use the cpu number +1 as spinlock valueMartin Schwidefsky2017-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The queued spinlock code will come out simpler if the encoding of the CPU that holds the spinlock is (cpu+1) instead of (~cpu). Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/topology: add detection of dedicated vs shared CPUsMartin Schwidefsky2017-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The topology information returned by STSI 15.x.x contains a flag if the CPUs of a topology-list are dedicated or shared. Make this information available if the machine provides topology information. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390/runtime_instrumentation: clean up struct runtime_instr_cbAlice Frosi2017-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update runtime_instr_cb structure to be consistent with the runtime instrumentation documentation. Signed-off-by: Alice Frosi <alice@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | s390: add support for FORTIFY_SOURCEHeiko Carstens2017-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the quite trivial backend for s390 which is required to enable FORTIFY_SOURCE support. See commit 6974f0c4555e ("include/linux/string.h: add the option of fortified string.h functions") for more details. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>