Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Subject: Re: [PATCH v5 07/10] tmp, tmp_tis: Implement usage counter for
 locality
To:     Jarkko Sakkinen <jarkko@kernel.org>
Cc:     peterhuewe@gmx.de, jgg@ziepe.ca, stefanb@linux.vnet.ibm.com,
        linux@mniewoehner.de, linux-integrity@vger.kernel.org,
        linux-kernel@vger.kernel.org, l.sanfilippo@kunbus.com,
        lukas@wunner.de, p.rosenberger@kunbus.com
References: <20220610110846.8307-1-LinoSanfilippo@gmx.de>
 <20220610110846.8307-8-LinoSanfilippo@gmx.de> <Yqojlh5J0660gfaT@iki.fi>
From:   Lino Sanfilippo <LinoSanfilippo@gmx.de>
Message-ID: <2b9e9b38-5ed7-aff1-9ead-534e9d857eda@gmx.de>
Date:   Thu, 16 Jun 2022 00:22:12 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <Yqojlh5J0660gfaT@iki.fi>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On 15.06.22 at 20:23, Jarkko Sakkinen wrote:
> On Fri, Jun 10, 2022 at 01:08:43PM +0200, LinoSanfilippo@gmx.de wrote:
>> From: Lino Sanfilippo <l.sanfilippo@kunbus.com>
>>
>> Implement a usage counter for the (default) locality used by the TPM TI=
S
>> driver:
>> Request the locality from the TPM if it has not been claimed yet, other=
wise
>> only increment the counter. Also release the locality if the counter is=
 0
>> otherwise only decrement the counter. Ensure thread-safety by protectin=
g
>> the counter with a mutex.
>>
>> This allows to request and release the locality from a thread and the
>> interrupt handler at the same time without the danger to interfere with
>> each other.
>>
>> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
>> ---
>>  drivers/char/tpm/tpm_tis_core.c | 30 ++++++++++++++++++++++++++++--
>>  drivers/char/tpm/tpm_tis_core.h |  2 ++
>>  2 files changed, 30 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis=
_core.c
>> index 028bec44362d..0ef74979bc2c 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -158,16 +158,26 @@ static bool check_locality(struct tpm_chip *chip,=
 int l)
>>  	return false;
>>  }
>>
>> +static int release_locality_locked(struct tpm_tis_data *priv, int l)
>> +{
>> +	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
>
> nit: empty line here
>
> Also it would not hurt to prefix it with tpm_tis.
>
> This is for simple and practical reasons, like grepping. I don't
> mind if you do that also for other functions (if you want to).
>

Ok, will do so.

Regards,
Lino