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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A440C433F5 for ; Tue, 10 May 2022 17:10:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347806AbiEJROp (ORCPT ); Tue, 10 May 2022 13:14:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347787AbiEJROl (ORCPT ); Tue, 10 May 2022 13:14:41 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D378BC12; Tue, 10 May 2022 10:10:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 948B9B81D2E; Tue, 10 May 2022 17:10:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6860C385A6; Tue, 10 May 2022 17:10:37 +0000 (UTC) Date: Tue, 10 May 2022 18:10:34 +0100 From: Catalin Marinas To: Herbert Xu 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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Herbert, Thanks for putting this together. On Tue, May 10, 2022 at 07:07:10PM +0800, Herbert Xu wrote: > diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h > index f50c5d1725da5..cdf12e51c53a0 100644 > --- a/include/crypto/algapi.h > +++ b/include/crypto/algapi.h > @@ -189,10 +189,34 @@ static inline void crypto_xor_cpy(u8 *dst, const u8 *src1, const u8 *src2, > } > } > > +static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm) > +{ > + return tfm->__crt_ctx; > +} > + > +static inline void *crypto_tfm_ctx_align(struct crypto_tfm *tfm, > + unsigned int align) > +{ > + if (align <= crypto_tfm_ctx_alignment()) > + align = 1; > + > + return PTR_ALIGN(crypto_tfm_ctx(tfm), align); > +} > + > static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm) > { > - return PTR_ALIGN(crypto_tfm_ctx(tfm), > - crypto_tfm_alg_alignmask(tfm) + 1); > + return crypto_tfm_ctx_align(tfm, crypto_tfm_alg_alignmask(tfm) + 1); > +} > + > +static inline void *crypto_tfm_ctx_dma(struct crypto_tfm *tfm) > +{ > + unsigned int align = 1; > + > +#ifdef ARCH_DMA_MINALIGN > + align = ARCH_DMA_MINALIGN; > +#endif > + > + return crypto_tfm_ctx_align(tfm, align); > } 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. 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. -- Catalin