From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753233Ab3F2UIQ (ORCPT ); Sat, 29 Jun 2013 16:08:16 -0400 Received: from mail-ie0-f171.google.com ([209.85.223.171]:65370 "EHLO mail-ie0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752055Ab3F2UIN (ORCPT ); Sat, 29 Jun 2013 16:08:13 -0400 MIME-Version: 1.0 In-Reply-To: <20130629195549.GE3353@n2100.arm.linux.org.uk> References: <1372467663-31425-1-git-send-email-santosh.shilimkar@ti.com> <20130629152959.GB31339@mtj.dyndns.org> <20130629172123.GA3353@n2100.arm.linux.org.uk> <20130629175743.GA382@mtj.dyndns.org> <20130629195549.GE3353@n2100.arm.linux.org.uk> Date: Sat, 29 Jun 2013 13:08:13 -0700 X-Google-Sender-Auth: 85uezcf1EK-hN8eDvXLbLj53b1k Message-ID: Subject: Re: [PATCH] WIP: HACK: LPAE, BOOTMEM and NO_BOOTMEM From: Yinghai Lu To: Russell King - ARM Linux Cc: Tejun Heo , Santosh Shilimkar , linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List , Catalin Marinas , Will Deacon , Nicolas Pitre , Ingo Molnar , Andrew Morton , "H. Peter Anvin" , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , "sparclinux@vger.kernel.org" , Sam Ravnborg , linux-arch@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 29, 2013 at 12:55 PM, Russell King - ARM Linux wrote: > On Sat, Jun 29, 2013 at 12:29:55PM -0700, Yinghai Lu wrote: >> >> On these SoCs which Santosh is working on, the main physical memory >> >> mapping is above 4GB, with just a small alias below 4GB to allow the >> >> system to boot without the MMU being on, as they may have more than >> >> 4GB of RAM. As I understand it, the small alias below 4GB is not >> >> suitable for use as a "lowmem" mapping. >> >> is that 32bit ARM or 64bit ARM? > > Only 32-bit has LPAE. Such things don't make sense on 64-bit CPUs. 32bit ARM does not support NO_BOOTMEM yet. arch/arc/Kconfig: select NO_BOOTMEM arch/arm64/Kconfig: select NO_BOOTMEM arch/sparc/Kconfig: select NO_BOOTMEM arch/x86/Kconfig:config NO_BOOTMEM so may need to 1. make 32bit ARM to use NO_BOOTMEM at first. 2 .we can add alloc_memblock as MACRO or inline for bootmem arches, 3. NO_BOOTMEM arches will have alloc_memblock in nobootmem.c 4. replace alloc_bootmem calling with alloc_memblock calling in core code. Thanks Yinghai From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Date: Sat, 29 Jun 2013 20:08:13 +0000 Subject: Re: [PATCH] WIP: HACK: LPAE, BOOTMEM and NO_BOOTMEM Message-Id: List-Id: References: <1372467663-31425-1-git-send-email-santosh.shilimkar@ti.com> <20130629152959.GB31339@mtj.dyndns.org> <20130629172123.GA3353@n2100.arm.linux.org.uk> <20130629175743.GA382@mtj.dyndns.org> <20130629195549.GE3353@n2100.arm.linux.org.uk> In-Reply-To: <20130629195549.GE3353@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Russell King - ARM Linux Cc: Tejun Heo , Santosh Shilimkar , linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List , Catalin Marinas , Will Deacon , Nicolas Pitre , Ingo Molnar , Andrew Morton , "H. Peter Anvin" , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , "sparclinux@vger.kernel.org" , Sam Ravnborg , linux-arch@vger.kernel.org On Sat, Jun 29, 2013 at 12:55 PM, Russell King - ARM Linux wrote: > On Sat, Jun 29, 2013 at 12:29:55PM -0700, Yinghai Lu wrote: >> >> On these SoCs which Santosh is working on, the main physical memory >> >> mapping is above 4GB, with just a small alias below 4GB to allow the >> >> system to boot without the MMU being on, as they may have more than >> >> 4GB of RAM. As I understand it, the small alias below 4GB is not >> >> suitable for use as a "lowmem" mapping. >> >> is that 32bit ARM or 64bit ARM? > > Only 32-bit has LPAE. Such things don't make sense on 64-bit CPUs. 32bit ARM does not support NO_BOOTMEM yet. arch/arc/Kconfig: select NO_BOOTMEM arch/arm64/Kconfig: select NO_BOOTMEM arch/sparc/Kconfig: select NO_BOOTMEM arch/x86/Kconfig:config NO_BOOTMEM so may need to 1. make 32bit ARM to use NO_BOOTMEM at first. 2 .we can add alloc_memblock as MACRO or inline for bootmem arches, 3. NO_BOOTMEM arches will have alloc_memblock in nobootmem.c 4. replace alloc_bootmem calling with alloc_memblock calling in core code. Thanks Yinghai From mboxrd@z Thu Jan 1 00:00:00 1970 From: yinghai@kernel.org (Yinghai Lu) Date: Sat, 29 Jun 2013 13:08:13 -0700 Subject: [PATCH] WIP: HACK: LPAE, BOOTMEM and NO_BOOTMEM In-Reply-To: <20130629195549.GE3353@n2100.arm.linux.org.uk> References: <1372467663-31425-1-git-send-email-santosh.shilimkar@ti.com> <20130629152959.GB31339@mtj.dyndns.org> <20130629172123.GA3353@n2100.arm.linux.org.uk> <20130629175743.GA382@mtj.dyndns.org> <20130629195549.GE3353@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Jun 29, 2013 at 12:55 PM, Russell King - ARM Linux wrote: > On Sat, Jun 29, 2013 at 12:29:55PM -0700, Yinghai Lu wrote: >> >> On these SoCs which Santosh is working on, the main physical memory >> >> mapping is above 4GB, with just a small alias below 4GB to allow the >> >> system to boot without the MMU being on, as they may have more than >> >> 4GB of RAM. As I understand it, the small alias below 4GB is not >> >> suitable for use as a "lowmem" mapping. >> >> is that 32bit ARM or 64bit ARM? > > Only 32-bit has LPAE. Such things don't make sense on 64-bit CPUs. 32bit ARM does not support NO_BOOTMEM yet. arch/arc/Kconfig: select NO_BOOTMEM arch/arm64/Kconfig: select NO_BOOTMEM arch/sparc/Kconfig: select NO_BOOTMEM arch/x86/Kconfig:config NO_BOOTMEM so may need to 1. make 32bit ARM to use NO_BOOTMEM at first. 2 .we can add alloc_memblock as MACRO or inline for bootmem arches, 3. NO_BOOTMEM arches will have alloc_memblock in nobootmem.c 4. replace alloc_bootmem calling with alloc_memblock calling in core code. Thanks Yinghai