linux-kernel - Re: [PATCH v3 15/15] coresight: etm4x: Cleanup TRCRSCTLRn register accesses

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Message-ID: <CAJ9a7VhiJiRS77MvQg9XirvniwJ9GXD7Z-CzrWfg7T+NBRM+Bw@mail.gmail.com>
Date:   Tue, 12 Apr 2022 11:42:48 +0100
From:   Mike Leach <mike.leach@...aro.org>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>
Cc:     James Clark <James.Clark@....com>, suzuki.poulose@....com,
        coresight@...ts.linaro.org, Anshuman.Khandual@....com,
        leo.yan@...aro.com, Leo Yan <leo.yan@...aro.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 15/15] coresight: etm4x: Cleanup TRCRSCTLRn register accesses

On Wed, 23 Mar 2022 at 16:15, Mathieu Poirier
<mathieu.poirier@...aro.org> wrote:
>
> On Fri, Mar 04, 2022 at 05:19:12PM +0000, James Clark wrote:
> > This is a no-op change for style and consistency and has no effect on
> > the binary output by the compiler. In sysreg.h fields are defined as
> > the register name followed by the field name and then _MASK. This
> > allows for grepping for fields by name rather than using magic numbers.
> >
> > Signed-off-by: James Clark <james.clark@....com>
> > ---
> >  drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 7 +++++--
> >  drivers/hwtracing/coresight/coresight-etm4x.h       | 7 +++++++
> >  2 files changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> > index 3ae6f4432646..6ea8181816fc 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> > @@ -1726,8 +1726,11 @@ static ssize_t res_ctrl_store(struct device *dev,
> >       /* For odd idx pair inversal bit is RES0 */
> >       if (idx % 2 != 0)
> >               /* PAIRINV, bit[21] */
> > -             val &= ~BIT(21);
> > -     config->res_ctrl[idx] = val & GENMASK(21, 0);
> > +             val &= ~TRCRSCTLRn_PAIRINV;
> > +     config->res_ctrl[idx] = val & (TRCRSCTLRn_PAIRINV |
> > +                                    TRCRSCTLRn_INV |
> > +                                    TRCRSCTLRn_GROUP_MASK |
> > +                                    TRCRSCTLRn_SELECT_MASK);
> >       spin_unlock(&drvdata->spinlock);
> >       return size;
> >  }
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> > index 15704982357f..2c412841b126 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> > @@ -223,6 +223,13 @@
> >  #define TRCBBCTLR_MODE                               BIT(8)
> >  #define TRCBBCTLR_RANGE_MASK                 GENMASK(7, 0)
> >
> > +#define TRCRSCTLRn_PAIRINV                   BIT(21)
> > +#define TRCRSCTLRn_INV                               BIT(20)
> > +#define TRCRSCTLRn_GROUP_MASK                        GENMASK(19, 16)
> > +#define TRCRSCTLRn_SELECT_MASK                       GENMASK(15, 0)
> > +
> > +
> > +
>
> Two extra lines.
>
> >  /*
> >   * System instructions to access ETM registers.
> >   * See ETMv4.4 spec ARM IHI0064F section 4.3.6 System instructions
> > --
> > 2.28.0
> >


Reviewed-by: Mike Leach <mike.leach@...aro.org>

-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK