1. 02 Jan, 2018 1 commit
    • Suzuki K Poulose's avatar
      perf: ARM DynamIQ Shared Unit PMU support · 7520fa99
      Suzuki K Poulose authored
      Add support for the Cluster PMU part of the ARM DynamIQ Shared Unit (DSU).
      The DSU integrates one or more cores with an L3 memory system, control
      logic, and external interfaces to form a multicore cluster. The PMU
      allows counting the various events related to L3, SCU etc, along with
      providing a cycle counter.
      The PMU can be accessed via system registers, which are common
      to the cores in the same cluster. The PMU registers follow the
      semantics of the ARMv8 PMU, mostly, with the exception that
      the counters record the cluster wide events.
      This driver is mostly based on the ARMv8 and CCI PMU drivers.
      The driver only supports ARM64 at the moment. It can be extended
      to support ARM32 by providing register accessors like we do in
      Cc: Mark Rutland <[email protected]>
      Cc: Will Deacon <[email protected]>
      Reviewed-by: default avatarJonathan Cameron <[email protected]>
      Reviewed-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarSuzuki K Poulose <[email protected]>
      Signed-off-by: default avatarWill Deacon <[email protected]>
  2. 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 <[email protected]>
      Reviewed-by: default avatarPhilippe Ombredanne <[email protected]>
      Reviewed-by: default avatarThomas Gleixner <[email protected]>
      Signed-off-by: default avatarGreg Kroah-Hartman <[email protected]>
  3. 19 Oct, 2017 1 commit
  4. 18 Oct, 2017 1 commit
    • Will Deacon's avatar
      drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension · d5d9696b
      Will Deacon authored
      The ARMv8.2 architecture introduces the optional Statistical Profiling
      Extension (SPE).
      SPE can be used to profile a population of operations in the CPU pipeline
      after instruction decode. These are either architected instructions (i.e.
      a dynamic instruction trace) or CPU-specific uops and the choice is fixed
      statically in the hardware and advertised to userspace via caps/. Sampling
      is controlled using a sampling interval, similar to a regular PMU counter,
      but also with an optional random perturbation to avoid falling into patterns
      where you continuously profile the same instruction in a hot loop.
      After each operation is decoded, the interval counter is decremented. When
      it hits zero, an operation is chosen for profiling and tracked within the
      pipeline until it retires. Along the way, information such as TLB lookups,
      cache misses, time spent to issue etc is captured in the form of a sample.
      The sample is then filtered according to certain criteria (e.g. load
      latency) that can be specified in the event config (described under
      format/) and, if the sample satisfies the filter, it is written out to
      memory as a record, otherwise it is discarded. Only one operation can
      be sampled at a time.
      The in-memory buffer is linear and virtually addressed, raising an
      interrupt when it fills up. The PMU driver handles these interrupts to
      give the appearance of a ring buffer, as expected by the AUX code.
      The in-memory trace-like format is self-describing (though not parseable
      in reverse) and written as a series of records, with each record
      corresponding to a sample and consisting of a sequence of packets. These
      packets are defined by the architecture, although some have CPU-specific
      fields for recording information specific to the microarchitecture.
      As a simple example, a record generated for a branch instruction may
      consist of the following packets:
        0 (Address) : Virtual PC of the branch instruction
        1 (Type)    : Conditional direct branch
        2 (Counter) : Number of cycles taken from Dispatch to Issue
        3 (Address) : Virtual branch target + condition flags
        4 (Counter) : Number of cycles taken from Dispatch to Complete
        5 (Events)  : Mispredicted as not-taken
        6 (END)     : End of record
      It is also possible to toggle properties such as timestamp packets in
      each record.
      This patch adds support for SPE in the form of a new perf driver.
      Cc: Alexander Shishkin <[email protected]>
      Reviewed-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarWill Deacon <[email protected]>
  5. 11 Apr, 2017 2 commits
  6. 03 Apr, 2017 1 commit
    • Agustin Vega-Frias's avatar
      perf: qcom: Add L3 cache PMU driver · 3071f13d
      Agustin Vega-Frias authored
      This adds a new dynamic PMU to the Perf Events framework to program
      and control the L3 cache PMUs in some Qualcomm Technologies SOCs.
      The driver supports a distributed cache architecture where the overall
      cache for a socket is comprised of multiple slices each with its own PMU.
      Access to each individual PMU is provided even though all CPUs share all
      the slices. User space needs to aggregate to individual counts to provide
      a global picture.
      The driver exports formatting and event information to sysfs so it can
      be used by the perf user space tools with the syntaxes:
         perf stat -a -e l3cache_0_0/read-miss/
         perf stat -a -e l3cache_0_0/event=0x21/
      Acked-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarAgustin Vega-Frias <[email protected]>
      [will: fixed sparse issues]
      Signed-off-by: default avatarWill Deacon <[email protected]>
  7. 08 Feb, 2017 1 commit
  8. 15 Sep, 2016 1 commit
  9. 31 Jul, 2015 1 commit