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 12962C3DA4A for ; Fri, 2 Aug 2024 11:02:39 +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=nw1iqQVMOzq+ioAn1MHFepdFcLn2HlKNyKqm4YBYshw=; b=xSz3E6BTDx1KzMul4jPxgVXfqy 64nCCwqjOv1nxf1HxHRdumYjApTtabsF66esO8cQzQV25dOMkYgGAcSKmDrmownP7b+iFW44EsO6i 5iDx268X1aCODPsythxXbOGxO+TOpBQ/2hPCf5nyGZpaqPqkQffLibgVwm37AluvPopCKEdaRN9sQ 8zgV7kS4KYf079s+CbJzB91QPyvgfo9WKQTSCvu8MEX8gtPTmqvS6ezgKs1hLXb26L0WH6tB9me73 D0v9T8SRueRVRgJU4MNs7yg2jCWf83kAPttKL/ZEMmqU0mPJeXuXL02Oc1hd0/zLrDF8XHijSMLut jY42QaEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sZq3E-00000008brO-3pUB; Fri, 02 Aug 2024 11:02:24 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sZq2h-00000008beu-0eqK for linux-arm-kernel@lists.infradead.org; Fri, 02 Aug 2024 11:01:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender: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-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=nw1iqQVMOzq+ioAn1MHFepdFcLn2HlKNyKqm4YBYshw=; b=J1fIIrGCP9dpDOdQ00BA0t3cp5 /0qw8Bk3QxrxAXYcAub5QMMbCBCuQujhVJ2JidL20HeCD6qfGZITx09EynUB2ceGeJRFI9ouAw5yN DXqJs8MTddn2C5FHyM2tg/yLvXST2uRL4CwBlMFdB0F6ZRmSUdIf9wb1gLzPi9Z+d0H9YgRwFUTOq Q+z9ik+ZnSCKm4/r/jUzpgLluwh6Jcw3iNFlL8j5c1uLJpXYL1Zvit28JU8peTZNzGoVbq7QwSlg7 21uidRezn5a13HCNSyhxep5yZBZJAf0ZN7RQwSoTNEvWX53tbWib9mr8xOMEH4MbfCeGZNQh96T5G hDK2ibKQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:36616) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sZq2W-0006WZ-2O; Fri, 02 Aug 2024 12:01:40 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1sZq2Z-0007yZ-7U; Fri, 02 Aug 2024 12:01:43 +0100 Date: Fri, 2 Aug 2024 12:01:43 +0100 From: "Russell King (Oracle)" To: Jinjie Ruan Cc: bhe@redhat.com, akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] ARM: Support allocating crashkernel above 4G for LPAE Message-ID: References: <20240802092510.3915986-1-ruanjinjie@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240802092510.3915986-1-ruanjinjie@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240802_040151_214721_0F5AD507 X-CRM114-Status: GOOD ( 11.98 ) 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, Aug 02, 2024 at 05:25:10PM +0800, Jinjie Ruan wrote: > As ARM LPAE feature support accessing memory beyond the 4G limit, define > HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH macro to support reserving crash > memory above 4G for ARM32 LPAE. > > No test because there is no LPAE ARM32 hardware. Why are you submitting patches for features you can't test? I'm not going to apply this without it being properly tested, because I don't believe that this will work in the generic case. If the crash kernel is located in memory outside of the lower 4GiB of address space, and there is no alias within physical address space for that memory, then there is *no* *way* for such a kernel to boot. So, right now I believe this patch to be *fundamentally* wrong. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!