lwn.git/arch/s390/kernel/processor.c, branch docs-5.3

s390: report new CPU capabilities

2019-04-25T13:34:10+00:00

Add hardware capability bits and features tags to /proc/cpuinfo for 4 new CPU features: "Vector-Enhancements Facility 2" (tag "vxe2", hwcap 2^15) "Vector-Packed-Decimal-Enhancement Facility" (tag "vxp", hwcap 2^16) "Enhanced-Sort Facility" (tag "sort", hwcap 2^17) "Deflate-Conversion Facility" (tag "dflt", hwcap 2^18) Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: run user space and KVM guests with modified branch prediction

2018-02-05T13:48:50+00:00

Define TIF_ISOLATE_BP and TIF_ISOLATE_BP_GUEST and add the necessary plumbing in entry.S to be able to run user space and KVM guests with limited branch prediction. To switch a user space process to limited branch prediction the s390_isolate_bp() function has to be call, and to run a vCPU of a KVM guest associated with the current task with limited branch prediction call s390_isolate_bp_guest(). Signed-off-by: Martin Schwidefsky

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

s390/cpuinfo: show facilities as reported by stfle

2017-03-22T07:29:02+00:00

Add a new line to /proc/cpuinfo which shows all available facilities as reported by the stfle instruction: > cat /proc/cpuinfo ... facilities : 0 1 2 3 4 6 7 ... ... Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: add a system call for guarded storage

2017-03-22T07:14:25+00:00

This adds a new system call to enable the use of guarded storage for user space processes. The system call takes two arguments, a command and pointer to a guarded storage control block: s390_guarded_storage(int command, struct gs_cb *gs_cb); The second argument is relevant only for the GS_SET_BC_CB command. The commands in detail: 0 - GS_ENABLE Enable the guarded storage facility for the current task. The initial content of the guarded storage control block will be all zeros. After the enablement the user space code can use load-guarded-storage-controls instruction (LGSC) to load an arbitrary control block. While a task is enabled the kernel will save and restore the current content of the guarded storage registers on context switch. 1 - GS_DISABLE Disables the use of the guarded storage facility for the current task. The kernel will cease to save and restore the content of the guarded storage registers, the task specific content of these registers is lost. 2 - GS_SET_BC_CB Set a broadcast guarded storage control block. This is called per thread and stores a specific guarded storage control block in the task struct of the current task. This control block will be used for the broadcast event GS_BROADCAST. 3 - GS_CLEAR_BC_CB Clears the broadcast guarded storage control block. The guarded- storage control block is removed from the task struct that was established by GS_SET_BC_CB. 4 - GS_BROADCAST Sends a broadcast to all thread siblings of the current task. Every sibling that has established a broadcast guarded storage control block will load this control block and will be enabled for guarded storage. The broadcast guarded storage control block is used up, a second broadcast without a refresh of the stored control block with GS_SET_BC_CB will not have any effect. Signed-off-by: Martin Schwidefsky

sched/headers: Move task->mm handling methods to

2017-03-03T00:43:28+00:00

Move the following task->mm helper APIs into a new header file, , to further reduce the size and complexity of . Here are how the APIs are used in various kernel files: # mm_alloc(): arch/arm/mach-rpc/ecard.c fs/exec.c include/linux/sched/mm.h kernel/fork.c # __mmdrop(): arch/arc/include/asm/mmu_context.h include/linux/sched/mm.h kernel/fork.c # mmdrop(): arch/arm/mach-rpc/ecard.c arch/m68k/sun3/mmu_emu.c arch/x86/mm/tlb.c drivers/gpu/drm/amd/amdkfd/kfd_process.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/infiniband/hw/hfi1/file_ops.c drivers/vfio/vfio_iommu_spapr_tce.c fs/exec.c fs/proc/base.c fs/proc/task_mmu.c fs/proc/task_nommu.c fs/userfaultfd.c include/linux/mmu_notifier.h include/linux/sched/mm.h kernel/fork.c kernel/futex.c kernel/sched/core.c mm/khugepaged.c mm/ksm.c mm/mmu_context.c mm/mmu_notifier.c mm/oom_kill.c virt/kvm/kvm_main.c # mmdrop_async_fn(): include/linux/sched/mm.h # mmdrop_async(): include/linux/sched/mm.h kernel/fork.c # mmget_not_zero(): fs/userfaultfd.c include/linux/sched/mm.h mm/oom_kill.c # mmput(): arch/arc/include/asm/mmu_context.h arch/arc/kernel/troubleshoot.c arch/frv/mm/mmu-context.c arch/powerpc/platforms/cell/spufs/context.c arch/sparc/include/asm/mmu_context_32.h drivers/android/binder.c drivers/gpu/drm/etnaviv/etnaviv_gem.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/core/uverbs_main.c drivers/infiniband/hw/mlx4/main.c drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/iommu/amd_iommu_v2.c drivers/iommu/intel-svm.c drivers/lguest/lguest_user.c drivers/misc/cxl/fault.c drivers/misc/mic/scif/scif_rma.c drivers/oprofile/buffer_sync.c drivers/vfio/vfio_iommu_type1.c drivers/vhost/vhost.c drivers/xen/gntdev.c fs/exec.c fs/proc/array.c fs/proc/base.c fs/proc/task_mmu.c fs/proc/task_nommu.c fs/userfaultfd.c include/linux/sched/mm.h kernel/cpuset.c kernel/events/core.c kernel/events/uprobes.c kernel/exit.c kernel/fork.c kernel/ptrace.c kernel/sys.c kernel/trace/trace_output.c kernel/tsacct.c mm/memcontrol.c mm/memory.c mm/mempolicy.c mm/migrate.c mm/mmu_notifier.c mm/nommu.c mm/oom_kill.c mm/process_vm_access.c mm/rmap.c mm/swapfile.c mm/util.c virt/kvm/async_pf.c # mmput_async(): include/linux/sched/mm.h kernel/fork.c mm/oom_kill.c # get_task_mm(): arch/arc/kernel/troubleshoot.c arch/powerpc/platforms/cell/spufs/context.c drivers/android/binder.c drivers/gpu/drm/etnaviv/etnaviv_gem.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/hw/mlx4/main.c drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/iommu/amd_iommu_v2.c drivers/iommu/intel-svm.c drivers/lguest/lguest_user.c drivers/misc/cxl/fault.c drivers/misc/mic/scif/scif_rma.c drivers/oprofile/buffer_sync.c drivers/vfio/vfio_iommu_type1.c drivers/vhost/vhost.c drivers/xen/gntdev.c fs/proc/array.c fs/proc/base.c fs/proc/task_mmu.c include/linux/sched/mm.h kernel/cpuset.c kernel/events/core.c kernel/exit.c kernel/fork.c kernel/ptrace.c kernel/sys.c kernel/trace/trace_output.c kernel/tsacct.c mm/memcontrol.c mm/memory.c mm/mempolicy.c mm/migrate.c mm/mmu_notifier.c mm/nommu.c mm/util.c # mm_access(): fs/proc/base.c include/linux/sched/mm.h kernel/fork.c mm/process_vm_access.c # mm_release(): arch/arc/include/asm/mmu_context.h fs/exec.c include/linux/sched/mm.h include/uapi/linux/sched.h kernel/exit.c kernel/fork.c Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/headers: Prepare to remove the dependency from

2017-03-02T07:42:37+00:00

Update code that relied on sched.h including various MM types for them. This will allow us to remove the include from . Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

mm: add new mmgrab() helper

2017-02-28T02:43:48+00:00

Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/' git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. (Michal Hocko provided most of the kerneldoc comment.) Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum Acked-by: Michal Hocko Acked-by: Peter Zijlstra (Intel) Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

s390: report new vector facilities

2017-02-08T13:13:24+00:00

Add hardware capability bits and feature tags to /proc/cpuinfo for the "Vector Packed Decimal Facility" (tag "vxd" / hwcap bit 2^12) and the "Vector Enhancements Facility 1" (tag "vxe" / hwcap bit 2^13). Signed-off-by: Martin Schwidefsky

s390: use false/true when using bool

2017-01-16T06:27:54+00:00

Yet another trivial patch to reduce the noise that coccinelle generates. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky