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 A138CC531C9 for ; Fri, 24 Jul 2026 05:29:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=q53deWRRK/b91M73sD9YZ3ZgsNtt8lj3y8LlgTKiW5A=; b=vabuNDhCnE0kzLx0OtX0xzlxyg 6VOjr9p3dlJmLzLfguZpYZhhigHQZqe+h2wymIqxkL8YLMhV4Tg+ge+6jdp2bkGwQ0H7XV+eyL2c5 JsOxh9S0BNFj+PNgE16H2nX7CHQWwaPoMgx2urHcYjYtG+/8O8wIbrRvGejE8tsdyvVI7e0jtx6dw U13NKMueh7jhoEaHOJfh5JxLtOQSTqUz8f6fI40UQbyZWStTfIt/WH4Amy125A6pkNoWNS+hJZ8lc ARRsckgwNbK4sOCoWZtaKjAaW2yLP3QuHRDLDeuTzlCMlWFGDkuGU9bqd0dAk1G2K/wJkxwb4hmX0 hlx+SpLg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wn8T5-0000000FVg4-0le2; Fri, 24 Jul 2026 05:29:08 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wn8T3-0000000FVfx-3avY for linux-arm-kernel@lists.infradead.org; Fri, 24 Jul 2026 05:29:05 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 0306543FE7; Fri, 24 Jul 2026 05:29:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 657471F000E9; Fri, 24 Jul 2026 05:29:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784870944; bh=q53deWRRK/b91M73sD9YZ3ZgsNtt8lj3y8LlgTKiW5A=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=L+bk7VgwsbrJ8l4jJtUHhfiAwHSs/8g1M3vrAb3vwvR5wovGNLum4KO14XHHWT/MD qK6s3m9ftLdWqrK7FdCDXZBpydWxM9N5PxHJcggouPF2KI41ZDqjep5KSjujBHKGM7 ZQlidywgGaNOsnom9QTwGrLwfwVXobaMDi8eorHs= Date: Fri, 24 Jul 2026 07:28:53 +0200 From: Greg Kroah-Hartman To: Eric Biggers Cc: linux-crypto@vger.kernel.org, Herbert Xu , linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Demi Marie Obenour , Bartosz Golaszewski , Kuldeep Singh , Dmitry Baryshkov Subject: Re: [PATCH] crypto: qce - Remove driver Message-ID: <2026072410-drained-acts-3502@gregkh> References: <20260724050645.223799-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260724050645.223799-1-ebiggers@kernel.org> 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jul 23, 2026 at 10:06:45PM -0700, Eric Biggers wrote: > This obsolete driver was already marked as BROKEN. However, keeping > BROKEN code around in the tree is unnecessary and causes problems. It's > much better to just remove it entirely. Let's do that. > > Crypto acceleration remains well-supported on Qualcomm SoCs via the > Qualcomm Inline Crypto Engine and the ARMv8 Crypto Extensions, which are > what Linux actually uses in practice. The obsolete QCE driver is a > dead-end approach. It's extremely slow and just doesn't work well. > > While there's been discussion around using QCE for restricted media > content protection, that functionality has very little to do with the > current crypto API driver and belongs in a separate, clean proposal > (likely under a different subsystem/directory). > > The extensive reasons for marking this driver as BROKEN were already > documented in commit df373d39c6f0 ("crypto: qce - Mark QCE as BROKEN"). > > Since then, it's also been found that under realistic workloads, the > driver is not only ~48x slower than ARMv8 CE, but due to massive driver > overhead it actually consumes significantly *more* CPU cycles than doing > the hashing directly on the CPU -- with much of that time spent in > non-preemptible hardirq and softirq contexts > (https://lore.kernel.org/linux-crypto/20260724020608.GA51735@sol/). The > proposed BAM locking fixes would only further degrade performance. > > Additional bugs have been found as well > (https://lore.kernel.org/linux-crypto/20260723205801.GD110634@quark/). > Pending fixes for some bugs don't change the big picture. Nor have > security-related claims held up. Of course, these issues are largely > moot anyway when this driver's functionality isn't being used in > practice, beyond the module loading due to it being in the kconfig. > > Note that this removal does *not* imply that various other drivers in > drivers/crypto/ don't have similar issues. They do. Rather, the > evidence is just exceptionally clear for this one, in part because > hardware availability has enabled independent testing. > > Signed-off-by: Eric Biggers Acked-by: Greg Kroah-Hartman