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 C9E4BD47CDE for ; Fri, 16 Jan 2026 12:06:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: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=ZSXsGg47LigshzAAw8DzoAw3ZijHz7xMa7QAo37NLMY=; b=ZESglfuhNXKpPPGA6DeC+2BYdn lZaG9DX0NFlYWUnbroHwW14Pbp3Cd6Np2xKdB9Vaaa+wEaz30rvYBbpEjtFn54LxsvrM/SqFvVbym I2Qoe1V7jktetAok18aB1E9PWZK4zb43WXoJutJ98FGAmV3AGdzBMq1gJN4tVSuEWagK/+4Wrnisa cnOzXF0UHoFyMj410dq8Bl9iFWE/tJ8Ic6qtfuROtcmO3BucXVN0tilboRmk28io2MsWdrrbdB5VH FAyevlwWZkN5oLZv337PKZILhRLtFNI6r49RM+c3Hys6tu5V2Xs62275wC+Vjwpx77cKGXfIklzq5 SaIN448w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vgib9-0000000E5KF-42ct; Fri, 16 Jan 2026 12:06:39 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vgib6-0000000E5Jj-3mAi for linux-arm-kernel@lists.infradead.org; Fri, 16 Jan 2026 12:06:38 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B86B81515; Fri, 16 Jan 2026 04:06:28 -0800 (PST) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6A2033F694; Fri, 16 Jan 2026 04:06:34 -0800 (PST) Date: Fri, 16 Jan 2026 12:06:31 +0000 From: Catalin Marinas To: Breno Leitao Cc: Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, clm@fb.com Subject: Re: [PATCH] arm64: mm: warn once for ioremap attempts on RAM mappings Message-ID: References: <20251222-arm64_ioremap-v1-1-30ff5f718b61@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251222-arm64_ioremap-v1-1-30ff5f718b61@debian.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260116_040636_974509_EB51195A X-CRM114-Status: GOOD ( 10.33 ) 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 Mon, Dec 22, 2025 at 07:28:55AM -0800, Breno Leitao wrote: > Replace WARN_ON with WARN_ONCE when detecting attempts to ioremap > RAM. This prevents log spam when a misbehaving driver repeatedly tries > to map RAM via ioremap. > > A single warning is more than enough to show the broken code path, and > extra reports don't add extra information. > > Warning floods have been seen in production environments where broken > external drivers hit this code path thousand of times, causing > unnecessary messages to be printed and pressure on the serial console. > > Signed-off-by: Breno Leitao It looks fine to me but it's not urgent for 6.19, so I'll leave it to Will. Acked-by: Catalin Marinas