From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Theodore Y. Ts'o" Subject: Re: [PATCH 0/4] arm64: wire CRC32 instructions into core crc32 routines Date: Mon, 27 Aug 2018 10:53:52 -0400 Message-ID: <20180827145352.GF2311@thunk.org> References: <20180827110245.14812-1-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, will.deacon@arm.com, catalin.marinas@arm.com, herbert@gondor.apana.org.au, ebiggers@google.com, suzuki.poulose@arm.com, linux-kernel@vger.kernel.org To: Ard Biesheuvel Return-path: Content-Disposition: inline In-Reply-To: <20180827110245.14812-1-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Mon, Aug 27, 2018 at 01:02:41PM +0200, Ard Biesheuvel wrote: > While this is not known to cause performance issues, calling a table based > time variant implementation with a non-negligible D-cache footprint (8 KB) > is wasteful in any case, and now that the crc32 instructions have been made > mandatory in the architecture, let's wire them up into the core crc routines. Stupid question --- are there any arm64 SOC's out there which do *not* have the crc32 instructions? Presumably there won't be in the future, because it's now mandatory --- but where there any in the past? - Ted From mboxrd@z Thu Jan 1 00:00:00 1970 From: tytso@mit.edu (Theodore Y. Ts'o) Date: Mon, 27 Aug 2018 10:53:52 -0400 Subject: [PATCH 0/4] arm64: wire CRC32 instructions into core crc32 routines In-Reply-To: <20180827110245.14812-1-ard.biesheuvel@linaro.org> References: <20180827110245.14812-1-ard.biesheuvel@linaro.org> Message-ID: <20180827145352.GF2311@thunk.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 27, 2018 at 01:02:41PM +0200, Ard Biesheuvel wrote: > While this is not known to cause performance issues, calling a table based > time variant implementation with a non-negligible D-cache footprint (8 KB) > is wasteful in any case, and now that the crc32 instructions have been made > mandatory in the architecture, let's wire them up into the core crc routines. Stupid question --- are there any arm64 SOC's out there which do *not* have the crc32 instructions? Presumably there won't be in the future, because it's now mandatory --- but where there any in the past? - Ted