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From: Bartosz Golaszewski <brgl@bgdev.pl>
Date: Wed, 20 Dec 2023 13:05:35 +0100
Message-ID: <CAMRc=MfvKzOxPrmz1wmgWMwYUbNhWAjqoKOmcaggQntcDprLmQ@mail.gmail.com>
Subject: Re: [PATCH 4/4] gpiolib: cdev: replace locking wrappers for
 gpio_device with guards
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Kent Gibson <warthog618@gmail.com>, Peter Zijlstra <peterz@infradead.org>, 
	linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, andy@kernel.org
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On Wed, Dec 20, 2023 at 12:56=E2=80=AFPM Linus Walleij <linus.walleij@linar=
o.org> wrote:
>
> (+PeterZ)
>
> On Wed, Dec 20, 2023 at 2:52=E2=80=AFAM Kent Gibson <warthog618@gmail.com=
> wrote:
>
> > Replace the wrapping functions that inhibit removal of the gpio_device
> > with equivalent guard macros.
> >
> > Signed-off-by: Kent Gibson <warthog618@gmail.com>
> (...)
> > +DEFINE_CLASS(_read_sem_guard,
> > +            struct rw_semaphore *,
> > +            up_read(_T),
> > +            ({
> > +               down_read(sem);
> > +               sem;
> > +            }),
> > +            struct rw_semaphore *sem);
>
> Isn't this so generic that it should be in <linux/cleanup.h>?
>
> Otherwise all the patches look good to me.
>

We already have this:

DEFINE_GUARD(rwsem_read, struct rw_semaphore *, down_read(_T), up_read(_T))
DEFINE_GUARD(rwsem_write, struct rw_semaphore *, down_write(_T), up_write(_=
T))

DEFINE_FREE(up_read, struct rw_semaphore *, if (_T) up_read(_T))
DEFINE_FREE(up_write, struct rw_semaphore *, if (_T) up_write(_T))

This can surely be used here, right?

Bart

> Yours,
> Linus Walleij