1. 24 Sep, 2019 1 commit
  2. 27 Aug, 2019 1 commit
  3. 19 Jun, 2019 1 commit
  4. 21 Apr, 2019 2 commits
  5. 06 Mar, 2019 1 commit
  6. 13 Aug, 2018 1 commit
    • Aneesh Kumar K.V's avatar
      powerpc/mm/book3s/radix: Add mapping statistics · a2dc009a
      Aneesh Kumar K.V authored
      Add statistics that show how memory is mapped within the kernel linear mapping.
      This is similar to commit 37cd944c
       ("s390/pgtable: add mapping statistics")
      We don't do this with Hash translation mode. Hash uses one size (mmu_linear_psize)
      to map the kernel linear mapping and we print the linear psize during boot as
      "Page orders: linear mapping = 24, virtual = 16, io = 16, vmemmap = 24"
      A sample output looks like:
      DirectMap4k:           0 kB
      DirectMap64k:       18432 kB
      DirectMap2M:     1030144 kB
      DirectMap1G:    11534336 kB
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
  7. 30 Jul, 2018 1 commit
  8. 16 Jul, 2018 1 commit
  9. 03 Jun, 2018 5 commits
    • Nicholas Piggin's avatar
      powerpc/64s/radix: optimise pte_update · 85bcfaf6
      Nicholas Piggin authored
      Implementing pte_update with pte_xchg (which uses cmpxchg) is
      inefficient. A single larx/stcx. works fine, no need for the less
      efficient cmpxchg sequence.
      Then remove the memory barriers from the operation. There is a
      requirement for TLB flushing to load mm_cpumask after the store
      that reduces pte permissions, which is moved into the TLB flush
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    • Nicholas Piggin's avatar
      powerpc/64s/radix: avoid ptesync after set_pte and ptep_set_access_flags · f1cb8f9b
      Nicholas Piggin authored
      The ISA suggests ptesync after setting a pte, to prevent a table walk
      initiated by a subsequent access from missing that store and causing a
      spurious fault. This is an architectual allowance that allows an
      implementation's page table walker to be incoherent with the store
      However there is no correctness problem in taking a spurious fault in
      userspace -- the kernel copes with these at any time, so the updated
      pte will be found eventually. Spurious kernel faults on vmap memory
      must be avoided, so a ptesync is put into flush_cache_vmap.
      On POWER9 so far I have not found a measurable window where this can
      result in more minor faults, so as an optimisation, remove the costly
      ptesync from pte updates. If an implementation benefits from ptesync,
      it would be better to add it back in update_mmu_cache, so it's not
      done for things like fork(2).
      fork --fork --exec benchmark improved 5.2% (12400->13100).
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    • Nicholas Piggin's avatar
      powerpc/64s/radix: make ptep_get_and_clear_full non-atomic for the full case · f569bd94
      Nicholas Piggin authored
      This matches other architectures, when we know there will be no
      further accesses to the address (e.g., for teardown), page table
      entries can be cleared non-atomically.
      The comments about NMMU are bogus: all MMU notifiers (including NMMU)
      are released at this point, with their TLBs flushed. An NMMU access at
      this point would be a bug.
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    • Aneesh Kumar K.V's avatar
      powerpc/mm: Change function prototype · e4c1112c
      Aneesh Kumar K.V authored
      In later patch, we use the vma and psize to do tlb flush. Do the prototype
      update in separate patch to make the review easy.
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    • Aneesh Kumar K.V's avatar
      powerpc/mm/radix: Move function from radix.h to pgtable-radix.c · 044003b5
      Aneesh Kumar K.V authored
      In later patch we will update them which require them to be moved
      to pgtable-radix.c. Keeping the function in radix.h results in
      compile warning as below.
      ./arch/powerpc/include/asm/book3s/64/radix.h: In function ‘radix__ptep_set_access_flags’:
      ./arch/powerpc/include/asm/book3s/64/radix.h:196:28: error: dereferencing pointer to incomplete type ‘struct vm_area_struct’
        struct mm_struct *mm = vma->vm_mm;
      ./arch/powerpc/include/asm/book3s/64/radix.h:204:6: error: implicit declaration of function ‘atomic_read’; did you mean ‘__atomic_load’? [-Werror=implicit-function-declaration]
            atomic_read(&mm->context.copros) > 0) {
      ./arch/powerpc/include/asm/book3s/64/radix.h:204:21: error: dereferencing pointer to incomplete type ‘struct mm_struct’
            atomic_read(&mm->context.copros) > 0) {
      Instead of fixing header dependencies, we move the function to pgtable-radix.c
      Also the function is now large to be a static inline . Doing the
      move in separate patch helps in review.
      No functional change in this patch. Only code movement.
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
  10. 30 Mar, 2018 1 commit
  11. 01 Feb, 2018 1 commit
  12. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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
      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: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
  13. 08 Aug, 2017 1 commit
  14. 18 Jul, 2017 1 commit
    • Michael Ellerman's avatar
      powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y · 029d9252
      Michael Ellerman authored
      Currently even with STRICT_KERNEL_RWX we leave the __init text marked
      executable after init, which is bad.
      Add a hook to mark it NX (no-execute) before we free it, and implement
      it for radix and hash.
      Note that we use __init_end as the end address, not _einittext,
      because overlaps_kernel_text() uses __init_end, because there are
      additional executable sections other than .init.text between
      __init_begin and __init_end.
      Tested on radix and hash with:
        0:mon> p $__init_begin
        *** 400 exception occurred
      Fixes: 1e0fc9d1
       ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
  15. 04 Jul, 2017 1 commit
  16. 02 Jul, 2017 1 commit
  17. 31 Mar, 2017 2 commits
  18. 15 Feb, 2017 3 commits
  19. 31 Jan, 2017 2 commits
  20. 28 Nov, 2016 4 commits
  21. 13 Sep, 2016 2 commits
  22. 17 Jun, 2016 1 commit
  23. 11 May, 2016 2 commits
  24. 01 May, 2016 3 commits