From: Jon Hunter Subject: Re: [PATCH 2/2] crypto: arm - add build time test for CRC instruction support Date: Tue, 28 Feb 2017 15:54:13 +0000 Message-ID: References: <1488292617-27317-1-git-send-email-ard.biesheuvel@linaro.org> <1488292617-27317-2-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: herbert@gondor.apana.org.au To: Ard Biesheuvel , , , Return-path: In-Reply-To: <1488292617-27317-2-git-send-email-ard.biesheuvel@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-crypto.vger.kernel.org On 28/02/17 14:36, Ard Biesheuvel wrote: > The accelerated CRC32 module for ARM may use either the scalar CRC32 > instructions, the NEON 64x64 to 128 bit polynomial multiplication > (vmull.p64) instruction, or both, depending on what the current CPU > supports. > > However, this also requires support in binutils, and as it turns out, > versions of binutils exist that support the vmull.p64 instruction but > not the crc32 instructions. > > So refactor the Makefile logic so that this module only gets built if > binutils has support for both. > > Signed-off-by: Ard Biesheuvel Thanks! Acked-by: Jon Hunter Tested-by: Jon Hunter Cheers Jon -- nvpublic