linux-kernel - Re: [PATCH v2 1/4] regmap: provide regmap_field helpers for simple bit operations

lists.openwall.net		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-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <180eef7d0c4.d42849e060770.1995440542302495013@zohomail.com>
Date:   Sun, 22 May 2022 20:30:59 -0700
From:   Li Chen <lchen.firstlove@...omail.com>
To:     "Samuel Holland" <samuel@...lland.org>
Cc:     "Mark Brown" <broonie@...nel.org>,
        "linux-kernel" <linux-kernel@...r.kernel.org>,
        "Greg Kroah-Hartman" <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        "linux-gpio" <linux-gpio@...r.kernel.org>,
        "Linus Walleij" <linus.walleij@...aro.org>,
        "linux-arm-kernel" <linux-arm-kernel@...ts.infradead.org>,
        "Patrice Chotard" <patrice.chotard@...s.st.com>,
        "linux-sunxi" <linux-sunxi@...ts.linux.dev>,
        "Liam Girdwood" <lgirdwood@...il.com>,
        "Jaroslav Kysela" <perex@...ex.cz>,
        "Takashi Iwai" <tiwai@...e.com>, "Chen-Yu Tsai" <wens@...e.org>,
        "Jernej Skrabec" <jernej.skrabec@...il.com>,
        "Philipp Zabel" <p.zabel@...gutronix.de>
Subject: Re: [PATCH v2 1/4] regmap: provide regmap_field helpers for simple
 bit operations

Hi Samuel,

 ---- On Sun, 22 May 2022 20:09:55 -0700 Samuel Holland <samuel@...lland.org> wrote ----
 > Hi,
 > 
 > On 5/22/22 9:23 PM, Li Chen wrote:
 > > From: Li Chen <lchen@...arella.com>
 > > 
 > > We have set/clear/test operations for regmap, but not for regmap_field yet.
 > > So let's introduce regmap_field helpers too.
 > > 
 > > In many instances regmap_field_update_bits() is used for simple bit setting
 > > and clearing. In these cases the last argument is redundant and we can
 > > hide it with a static inline function.
 > > 
 > > This adds three new helpers for simple bit operations: set_bits,
 > > clear_bits and test_bits (the last one defined as a regular function).
 > > 
 > > Signed-off-by: Li Chen <lchen@...arella.com>
 > > ---
 > >  drivers/base/regmap/regmap.c | 22 +++++++++++++++++++++
 > >  include/linux/regmap.h       | 37 ++++++++++++++++++++++++++++++++++++
 > >  2 files changed, 59 insertions(+)
 > > 
 > > diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
 > > index 5e12f7cb5147..a37d6041b7bd 100644
 > > --- a/drivers/base/regmap/regmap.c
 > > +++ b/drivers/base/regmap/regmap.c
 > > @@ -2208,6 +2208,28 @@ int regmap_field_update_bits_base(struct regmap_field *field,
 > >  }
 > >  EXPORT_SYMBOL_GPL(regmap_field_update_bits_base);
 > >  
 > > +/**
 > > + * regmap_field_test_bits() - Check if all specified bits are set in a
 > > + *                            register field.
 > > + *
 > > + * @field: Register field to operate on
 > > + * @bits: Bits to test
 > > + *
 > > + * Returns -1 if the underlying regmap_field_read() fails, 0 if at least one of the
 > > + * tested bits is not set and 1 if all tested bits are set.
 > > + */
 > > +int regmap_field_test_bits(struct regmap_field *field, unsigned int bits)
 > > +{
 > > +    unsigned int val, ret;
 > > +
 > > +    ret = regmap_field_read(field, &val);
 > > +    if (ret)
 > > +        return ret;
 > > +
 > > +    return (val & bits) == bits;
 > > +}
 > > +EXPORT_SYMBOL_GPL(regmap_field_test_bits);
 > > +
 > >  /**
 > >   * regmap_fields_update_bits_base() - Perform a read/modify/write cycle a
 > >   *                                    register field with port ID
 > > diff --git a/include/linux/regmap.h b/include/linux/regmap.h
 > > index de81a94d7b30..10b410734d9e 100644
 > > --- a/include/linux/regmap.h
 > > +++ b/include/linux/regmap.h
 > > @@ -1324,6 +1324,22 @@ static inline int regmap_field_update_bits(struct regmap_field *field,
 > >                           NULL, false, false);
 > >  }
 > >  
 > > +static inline int regmap_field_set_bits(struct regmap_field *field,
 > > +                    unsigned int bits)
 > > +{
 > > +    return regmap_field_update_bits_base(field, bits, 0, NULL, false,
 > > +                         false);
 > > +}
 > > +
 > > +static inline int regmap_field_clear_bits(struct regmap_field *field,
 > > +                      unsigned int bits)
 > > +{
 > > +    return regmap_field_update_bits_base(field, bits, bits, NULL, false,
 > > +                         false);
 > 
 > The contents of these two functions are swapped when compared to their names.

Thanks for spotting this out!
Fixed in v3.

Regards,
Li
 > 
 > Regards,
 > Samuel
 > 
 > > +}
 > > +
 > > +int regmap_field_test_bits(struct regmap_field *field, unsigned int bits);
 > > +
 > >  static inline int
 > >  regmap_field_force_update_bits(struct regmap_field *field,
 > >                     unsigned int mask, unsigned int val)
 > > @@ -1757,6 +1773,27 @@ regmap_field_force_update_bits(struct regmap_field *field,
 > >      return -EINVAL;
 > >  }
 > >  
 > > +static inline int regmap_field_set_bits(struct regmap_field *field,
 > > +                    unsigned int bits)
 > > +{
 > > +    WARN_ONCE(1, "regmap API is disabled");
 > > +    return -EINVAL;
 > > +}
 > > +
 > > +static inline int regmap_field_clear_bits(struct regmap_field *field,
 > > +                      unsigned int bits)
 > > +{
 > > +    WARN_ONCE(1, "regmap API is disabled");
 > > +    return -EINVAL;
 > > +}
 > > +
 > > +static inline int regmap_field_test_bits(struct regmap_field *field,
 > > +                     unsigned int bits)
 > > +{
 > > +    WARN_ONCE(1, "regmap API is disabled");
 > > +    return -EINVAL;
 > > +}
 > > +
 > >  static inline int regmap_fields_write(struct regmap_field *field,
 > >                        unsigned int id, unsigned int val)
 > >  {
 > > 
 > 
 >