lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 15 Feb 2021 07:51:36 +0000
From:   Nicola Mazzucato <>
Subject: [PATCH v7 0/3] CPUFreq: Add support for opp-sharing cpus

Hi Viresh,

In this V7 posting I have reworked the CPUFreq scmi driver in a different
way as suggested in v6.
Essentially I believe it is more efficient to keep the support for opp-shared
in the _init() stage, rather than moving everything to _probe(), storing
whatever is required and reuse it only once in _init().
The reasons for this are:
- scmi-cpufreq has no init cases that would require a deferred probe.
- therefore, moving the all the cpus initialisation to probe, whilst possible,
  will result in a waste of memory, since we need to store cpumask and
  freq_table only for them to be reused just once later on at init.
- it does not appear to be functional justification for moving the init code
  to probe, which results in unnecessary overhead for both coding and review.
- this change is much smaller and only one patch required (1 file changed,
  52 insertions, 20 deletions) compared to a version where we first move init
  code to _probe and later add support for opp-v2 (2 patches, 1 file changed,
  194+34 insertions, 44+9 deletions, version with a linked list).
- this v7 implementation is much easier to maintain.

Many thanks,

  * Bring back common stuff for CPUs from _init stage to _probe
  * Remove patch "scmi-cpufreq: Move CPU initialisation to probe"

This v7 is based on Linux 5.11-rc6

  * Remove deferred probe, not occurring
  * Move common stuff for CPUs from _init stage to _probe

This V6 is rebased on next-20210111

  * Rework documentation of opp-shared within OPP node
  * Register EM only for the first CPU within cpumask in driver
  * Add check for nr_opp in driver before registering EM
  * Add comments on both dev_pm_opp_get_opp_count in driver
  * Remove redundant ret=0 in driver

This v5 is rebased on top of:
next-20201208 + Lukasz Luba's patches [1]

  * Remove unconditional set of opp_table->shared_opp to exclusive
  * Add implementation for scmi-cpufreq
  * Change subject

These patches are on top of:
next-20201201 + Lukasz Luba's patches (waiting for Rafael) [1]

  * Remove proposal for new 'cpu-performance-dependencies' as we instead
    can reuse the opp table.
  * Update documentation for devicetree/bindings/opp
  * Minor changes within opp to support empty opp table
  * Rework the RFC by adding a second proposal

  * Fix errors when running make dt_binding_check
  * Improve commit message description for the dt-binding
  * Add RFC for implementation in cpufreq-core and one of its

Nicola Mazzucato (2):
  scmi-cpufreq: Remove deferred probe
  scmi-cpufreq: Get opp_shared_cpus from opp-v2 for EM

Sudeep Holla (1):
  cpufreq: blacklist Arm Vexpress platforms in cpufreq-dt-platdev

 drivers/cpufreq/cpufreq-dt-platdev.c |  2 +
 drivers/cpufreq/scmi-cpufreq.c       | 70 +++++++++++++++++++++-------
 2 files changed, 54 insertions(+), 18 deletions(-)


Powered by blists - more mailing lists