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From: Jens Wiklander <jens.wiklander@linaro.org>
Date: Wed, 28 Feb 2024 12:48:31 +0100
Message-ID: <CAHUa44EunLWSsVgFbH8fQNhWz69MAHj2j-JFu+cguXxUDUvLSg@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] tee: optee: Move pool_op helper functions
To: Sumit Garg <sumit.garg@linaro.org>
Cc: Balint Dobszay <balint.dobszay@arm.com>, op-tee@lists.trustedfirmware.org, 
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-arm-kernel@lists.infradead.org, corbet@lwn.net, sudeep.holla@arm.com, 
	rdunlap@infradead.org, krzk@kernel.org, gyorgy.szing@arm.com
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On Wed, Feb 28, 2024 at 12:20=E2=80=AFPM Sumit Garg <sumit.garg@linaro.org>=
 wrote:
>
> On Wed, 28 Feb 2024 at 14:11, Jens Wiklander <jens.wiklander@linaro.org> =
wrote:
> >
> > On Wed, Feb 28, 2024 at 6:58=E2=80=AFAM Sumit Garg <sumit.garg@linaro.o=
rg> wrote:
> > >
> > > On Tue, 27 Feb 2024 at 21:20, Jens Wiklander <jens.wiklander@linaro.o=
rg> wrote:
> > > >
> > > > On Tue, Feb 27, 2024 at 7:06=E2=80=AFAM Sumit Garg <sumit.garg@lina=
ro.org> wrote:
> > [snip]
> > > > > > --- a/include/linux/tee_drv.h
> > > > > > +++ b/include/linux/tee_drv.h
> > > > > > @@ -275,6 +275,17 @@ void *tee_get_drvdata(struct tee_device *t=
eedev);
> > > > > >  struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx=
, size_t size);
> > > > > >  struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *c=
tx, size_t size);
> > > > > >
> > > > > > +int tee_shm_pool_op_alloc_helper(struct tee_shm_pool *pool, st=
ruct tee_shm *shm,
> > > > > > +                                size_t size, size_t align,
> > > > > > +                                int (*shm_register)(struct tee=
_context *ctx,
> > > > > > +                                                    struct tee=
_shm *shm,
> > > > > > +                                                    struct pag=
e **pages,
> > > > > > +                                                    size_t num=
_pages,
> > > > > > +                                                    unsigned l=
ong start));
> > > > > > +void tee_shm_pool_op_free_helper(struct tee_shm_pool *pool, st=
ruct tee_shm *shm,
> > > > > > +                                int (*shm_unregister)(struct t=
ee_context *ctx,
> > > > > > +                                                      struct t=
ee_shm *shm));
> > > > > > +
> > > > >
> > > > > These rather belong to drivers/tee/tee_private.h as we shouldn't
> > > > > expose them to other kernel client drivers.
> > > >
> > > > This is the right place, this .h file is for TEE drivers too.
> > > >
> > >
> > > But this is shared with other kernel TEE client drivers and we
> > > shouldn't expose internal APIs which aren't meant for them with a sid=
e
> > > effect of API abuse too. Any particular reason to not use
> > > drivers/tee/tee_private.h?
> >
> > drivers/tee/tee_private.h is supposed to be used internally by only
> > the files in drivers/tee.
>
> How about "struct tee_device" being in drivers/tee/tee_private.h?

What about it?

>
> > If you look in include/linux/tee_drv.h
> > you'll find a few functions and other definitions that a kernel TEE
> > client driver should not use, for instance, tee_device_register() and
> > tee_device_unregister(). This kernel TEE client interface was
> > introduced with commit 25559c22cef8 ("tee: add kernel internal client
> > interface"). include/linux/tee_drv.h existed before we even had any
> > kernel TEE client interface.
>
> Anyhow, it looks like there is a chance for refactoring here. How
> about splitting this header further in something like
> include/linux/tee_core.h which will contain all the pieces relevant to
> TEE drivers?

Sure.

>
> BTW, this patch series can keep using include/linux/tee_drv.h for the
> time being.

Agreed.

Cheers,
Jens

>
> -Sumit
>
> >
> > Cheers,
> > Jens