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 944D4CD6E4C for ; Sat, 30 May 2026 16:19:58 +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=WxYmQxwwBxgWs6asR9XSCI+irQfqn2faBEqKE1hn53E=; b=fqeYhXBaomFukpjcjR27IZQwcz 8rJeJetoYWy7CnAkR5wHLO2cDVEY9GvG7r1bth9MOs1obnEQdzg08dcAr97sry+zLUuaZ6CvIeodw F5Nj21lmAxKXwOScLlXnWdBQusauwj0fSWTGXueObDERvr9KfBgGSzwgIscukuXzauuzHghrr0XgQ UcXGCj/5fTKz4KIPzhZHd8bVb1+ej4HpPrCOFioqF1VWQlG8VYVI0FeHFGcsI9uG45Jz2uz9knDrh pbPOtlZPdgq2Qx4IiJaKUfxpBu8mXnpKFWIEEXDcCerHpvn6lCngpvNwZc+2pc/lK0h9sOD/28u/P FCvcvyXg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wTMPf-00000008v8T-1UYX; Sat, 30 May 2026 16:19:51 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wTMPd-00000008v8N-0ESE for linux-arm-kernel@lists.infradead.org; Sat, 30 May 2026 16:19:49 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 18ACC600BB; Sat, 30 May 2026 16:19:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD33E1F00893; Sat, 30 May 2026 16:19:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780157987; bh=WxYmQxwwBxgWs6asR9XSCI+irQfqn2faBEqKE1hn53E=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=WZl0+4I9eq0OPPyxyDBdqCGRR+y0CoJpx7P9J1ZNHafWZGZX1fuK9HT7HOCSp1FVU 9ddWJ9lDITFjq9eKGfZ8XgcPI1Gceue8QxkZpOu0JwKjN75XEWJg4tA2a8UNAkWZvu d2ASsHkW3EY1IZ3rOpPzq31XPfEMQM756K5+/fSW612wkX78yv2eAZ66ejeZV4LlfY gAu+RNJYW42KKsssq+PHsl1z2ZSd/eOK+QZCgtAc5FgOD8sjUj3miMaJcP2gtaD17q 8U+HAlTtH77+9KCSbzDnS36KQEJCJesVoZVR5wfQkL3btqSLgCjvtjIMAmDS1I+rUb wf48OWQ3Lcqyg== Date: Sat, 30 May 2026 19:19:36 +0300 From: Mike Rapoport To: Ard Biesheuvel Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, Ard Biesheuvel , Ryan Roberts , Anshuman Khandual , Kevin Brodsky , Liz Prucka , Seth Jenkins , Kees Cook , David Hildenbrand , Andrew Morton , Jann Horn , linux-mm@kvack.org, linux-hardening@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , Geert Uytterhoeven Subject: Re: [PATCH v7 12/15] sh: Drop cache flush of the zero page at boot Message-ID: References: <20260529150150.1670604-17-ardb+git@google.com> <20260529150150.1670604-29-ardb+git@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260529150150.1670604-29-ardb+git@google.com> 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 Fri, May 29, 2026 at 05:02:03PM +0200, Ard Biesheuvel wrote: > From: Ard Biesheuvel > > SuperH performs cache maintenance on the zero page during boot, > presumably because before commit > > 6215d9f4470f ("arch, mm: consolidate empty_zero_page") > > the zero page did double duty as a boot params region, and was cleared > separately, as it was not part of BSS. The memset() in question was > dropped by that commit, but the __flush_wback_region() call remained. > > As empty_zero_page[] has been moved to BSS, it can be treated as any > other BSS memory, and so the cache flush can be dropped. > > Cc: Yoshinori Sato > Cc: Rich Felker > Cc: John Paul Adrian Glaubitz > Cc: Mike Rapoport > Cc: Geert Uytterhoeven > Signed-off-by: Ard Biesheuvel Acked-by: Mike Rapoport (Microsoft) > --- > arch/sh/mm/init.c | 3 --- > 1 file changed, 3 deletions(-) -- Sincerely yours, Mike.