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From:   Horia Geanta <horia.geanta@nxp.com>
To:     Andrey Smirnov <andrew.smirnov@gmail.com>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>
CC:     Chris Healy <cphealy@gmail.com>,
        Lucas Stach <l.stach@pengutronix.de>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Iuliana Prodan <iuliana.prodan@nxp.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH v6 6/7] crypto: caam - enable prediction resistance in
 HRWNG
Thread-Topic: [PATCH v6 6/7] crypto: caam - enable prediction resistance in
 HRWNG
Thread-Index: AQHVxjouh/c8xz5csUKnQ9CkhtEExg==
Date:   Wed, 22 Jan 2020 13:37:11 +0000
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 <20200108154047.12526-7-andrew.smirnov@gmail.com>
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On 1/21/2020 6:38 PM, Horia Geanta wrote:=0A=
> On 1/8/2020 5:42 PM, Andrey Smirnov wrote:=0A=
>> @@ -275,12 +276,25 @@ static int instantiate_rng(struct device *ctrldev,=
 int state_handle_mask,=0A=
>>  		return -ENOMEM;=0A=
>>  =0A=
>>  	for (sh_idx =3D 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) {=0A=
>> +		const u32 rdsta_if =3D RDSTA_IF0 << sh_idx;=0A=
>> +		const u32 rdsta_pr =3D RDSTA_PR0 << sh_idx;=0A=
>> +		const u32 rdsta_mask =3D rdsta_if | rdsta_pr;=0A=
>>  		/*=0A=
>>  		 * If the corresponding bit is set, this state handle=0A=
>>  		 * was initialized by somebody else, so it's left alone.=0A=
>>  		 */=0A=
>> -		if ((1 << sh_idx) & state_handle_mask)=0A=
>> -			continue;=0A=
>> +		if (rdsta_if & state_handle_mask) {=0A=
>> +			if (rdsta_pr & state_handle_mask)=0A=
> instantiate_rng() is called with=0A=
> 	state_handle_mask =3D rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_IFMASK;=0A=
> so if (rdsta_pr & state_handle_mask) will always be false,=0A=
> leading to unneeded state handle re-initialization.=0A=
> =0A=
Sorry, I missed this change:=0A=
-#define RDSTA_IFMASK (RDSTA_IF1 | RDSTA_IF0)=0A=
+#define RDSTA_IFMASK (RDSTA_PR1 | RDSTA_PR0 | RDSTA_IF1 | RDSTA_IF0)=0A=
=0A=
which means code is correct (though I must admit not so intuitive).=0A=
=0A=
Horia=0A=