From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 12935C433F5 for ; Thu, 12 May 2022 03:58:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CNvt8CvkuX9V9aZDgAeaS1dG8Pugmagm82aIMbBpHeQ=; b=lpHHp5rEcfyXxW ifE2RFjLHlekgZnc5AvG1ld1GgY+hmX805ihP9zGAAYWJlHMMtSqBiORGs1bufcEq2TjuB004eD3H VqV9DkshvG4s7likwFslHH5mMsPwA1M3n8E3j8zWG0f6bB2YlhumJ4YkTNqpiAQWhm8Lu9vGDq0SY NIU13ppoERfHQiEkb5AaI2b0yDD+9dZky8aYZBUDFxLpTqRnquDcduKfbrkxgU0ff9qhoI1beVfcS 2Rk7SijgQsHJ+owPPILB4fU2jX2Ta+23Xo2pdVDph5gvfjK3KzdtxQhhULs4kopQ2n0M1/ldTWESC ZmSx9blm/18Xf+jEBkjA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nozxE-009pDU-1m; Thu, 12 May 2022 03:57:32 +0000 Received: from helcar.hmeau.com ([216.24.177.18] helo=fornost.hmeau.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nozxA-009p8o-I9 for linux-arm-kernel@lists.infradead.org; Thu, 12 May 2022 03:57:30 +0000 Received: from gwarestrin.arnor.me.apana.org.au ([192.168.103.7]) by fornost.hmeau.com with smtp (Exim 4.94.2 #2 (Debian)) id 1nozwj-00CmlI-4v; Thu, 12 May 2022 13:57:02 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Thu, 12 May 2022 11:57:01 +0800 Date: Thu, 12 May 2022 11:57:01 +0800 From: Herbert Xu To: Catalin Marinas Cc: Ard Biesheuvel , Will Deacon , Marc Zyngier , Arnd Bergmann , Greg Kroah-Hartman , Andrew Morton , Linus Torvalds , Linux Memory Management List , Linux ARM , Linux Kernel Mailing List , "David S. Miller" , Linux Crypto Mailing List Subject: Re: [RFC PATCH 2/7] crypto: api - Add crypto_tfm_ctx_dma Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220511_205728_614883_72FAAB64 X-CRM114-Status: GOOD ( 15.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, May 10, 2022 at 06:10:34PM +0100, Catalin Marinas wrote: > > Is there a case where a driver needs the minimum alignment between > ARCH_DMA_MINALIGN and crypto_tfm_alg_alignmask()+1? Maybe for platforms > where ARCH_DMA_MINALIGN is 8 (fully coherent) but the device's bus > master alignment requirements are higher. Yes, for example on x86 aesni requires 16-byte alignment. > My plan is to have ARCH_DMA_MINALIGN always defined but potentially > higher than ARCH_KMALLOC_MINALIGN on specific architectures. I think > crypto_tfm_ctx_dma() should use ARCH_KMALLOC_MINALIGN (and no #ifdefs) > until I get my patches sorted and I'll replace it with ARCH_DMA_MINALIGN > once it's defined globally (still no #ifdefs). Currently in mainline > it's ARCH_KMALLOC_MINALIGN that gives the static DMA alignment. > > With the explicit crypto_tfm_ctx_dma(), can CRYPTO_MINALIGN_ATTR be > dropped entirely? This may be beneficial in reducing the structure size > when no DMA is required. We always need CRYPTO_MINALIGN to reflect what alignment kmalloc guarantees. It is used to minimise the amount of extra padding for users such aesni. This shouldn't have any impact on your plans though as once the drivers in question switch over to the DMA helpers you can safely lower ARCH_KMALLOC_MINALIGN. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel