linux-kernel - [RFT PATCH 0/9] drivers: qcom: rpmh-rsc: Cleanup / add lots of comments

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Message-Id: <20200306235951.214678-1-dianders@chromium.org>
Date:   Fri,  6 Mar 2020 15:59:42 -0800
From:   Douglas Anderson <dianders@...omium.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Maulik Shah <mkshah@...eaurora.org>
Cc:     Rajendra Nayak <rnayak@...eaurora.org>, mka@...omium.org,
        evgreen@...omium.org, swboyd@...omium.org,
        Lina Iyer <ilina@...eaurora.org>,
        Douglas Anderson <dianders@...omium.org>,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [RFT PATCH 0/9] drivers: qcom: rpmh-rsc: Cleanup / add lots of comments

In order to review Maulik's latest "rpmh_flush for non OSI targets"
patch series I've found myself trying to understand rpmh-rsc better.
To make it easier for others to do this in the future, add a whole lot
of comments / documentation.

As part of this there are a very small number of functional changes.
- We'll get a tiny performance boost by getting rid of the "cmd_cache"
  which I believe was unnecessary (though just to be sure, best to try
  this atop Maulik's patches where it should be super obvious that we
  always invalidate before writing sleep/wake TCSs.
- I think I've eliminated a possible deadlock on "nosmp" systems,
  though it was mostly theoretical.
- Possibly we could get a warning in some cases if I misunderstood how
  tcs_is_free() works.  It'd be easy to remove the warning, though.

These changes touch a lot of code in rpmh-rsc, so hopefully someone at
Qualcomm can test them out better than I did (I don't have every last
client of RPMH in my tree) and review them soon-ish so they can land
and future patches can be based on them.

I've tried to structure the patches so that simpler / less
controversial patches are first.  Those could certainly land on their
own without later patches.  Many of the patches could also be dropped
and the others would still apply if they are controversial.  If you
need help doing this then please yell.

With all that, enjoy.


Douglas Anderson (9):
  drivers: qcom: rpmh-rsc: Clean code reading/writing regs/cmds
  drivers: qcom: rpmh-rsc: Document the register layout better
  drivers: qcom: rpmh-rsc: Fold tcs_ctrl_write() into its single caller
  drivers: qcom: rpmh-rsc: Remove get_tcs_of_type() abstraction
  drivers: qcom: rpmh-rsc: A lot of comments
  drivers: qcom: rpmh-rsc: Only use "tcs_in_use" for ACTIVE_ONLY
  drivers: qcom: rpmh-rsc: Warning if tcs_write() used for non-active
  drivers: qcom: rpmh-rsc: spin_lock_irqsave() for tcs_invalidate()
  drivers: qcom: rpmh-rsc: Kill cmd_cache and find_match() with fire

 drivers/soc/qcom/rpmh-internal.h |  45 ++--
 drivers/soc/qcom/rpmh-rsc.c      | 390 +++++++++++++++++++++++--------
 2 files changed, 313 insertions(+), 122 deletions(-)

-- 
2.25.1.481.gfbce0eb801-goog