From: Garg Vakul-B16394 Subject: RE: [PATCH] crypto: caam - set RDB bit in security configuration register Date: Thu, 7 Feb 2013 04:38:46 +0000 Message-ID: <065BBB7616BCE543832A2EF096986B9417E955@039-SN2MPN1-011.039d.mgd.msft.net> References: <1360151266-28428-1-git-send-email-vakul@freescale.com> <20130206193315.cb27accf9a7a7f95870fb47f@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: "linux-crypto@vger.kernel.org" , Herbert Xu , "David S. Miller" , Liu Shengzhou-B36685 , Porosanu Alexandru-B06830 , "linux-kernel@vger.kernel.org" To: Phillips Kim-R1AAHA Return-path: Received: from tx2ehsobe003.messaging.microsoft.com ([65.55.88.13]:4326 "EHLO tx2outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751472Ab3BGEiw convert rfc822-to-8bit (ORCPT ); Wed, 6 Feb 2013 23:38:52 -0500 In-Reply-To: <20130206193315.cb27accf9a7a7f95870fb47f@freescale.com> Content-Language: en-US Sender: linux-crypto-owner@vger.kernel.org List-ID: > -----Original Message----- > From: Phillips Kim-R1AAHA > Sent: Thursday, February 07, 2013 7:03 AM > To: Garg Vakul-B16394 > Cc: linux-crypto@vger.kernel.org; Herbert Xu; David S. Miller; Liu > Shengzhou-B36685; Porosanu Alexandru-B06830; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] crypto: caam - set RDB bit in security configuration > register > > On Wed, 6 Feb 2013 17:17:46 +0530 > Vakul Garg wrote: > > > This change is required for post SEC-5.0 devices which have RNG4. > > Setting RDB > > wrap your commit message text to 75 chars Ok > > > in security configuration register allows CAAM to use the "Random Data > Buffer" > > to be filled by a single request. The Random Data Buffer is large > > enough for ten packets to get their IVs from a single request. If the > > Random Data Buffer is not enabled, then each IV causes a separate > > request, and RNG4 hardware cannot keep up resulting in lower IPSEC > throughput. > > Linux kernel IPSec or another IPSEC stack? how much lower? We measured USDPAA IPSEC throughput to be 1.9 times better on T4240 with this change. > > > + if (of_device_is_compatible(nprop, "fsl,sec-v5.0")) > > + setbits32(&topregs->ctrl.scfgr, SCFGR_RDBENABLE); > > + > > this belongs further down - at the end of the RNG4 initialization > section. Ok > > Kim