From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx108.postini.com [74.125.245.108]) by kanga.kvack.org (Postfix) with SMTP id D33FF6B0110 for ; Wed, 12 Sep 2012 20:08:37 -0400 (EDT) Message-ID: <505123FE.2090305@ti.com> Date: Wed, 12 Sep 2012 20:08:30 -0400 From: Cyril Chemparathy MIME-Version: 1.0 Subject: Re: [PATCH] mm: bootmem: use phys_addr_t for physical addresses References: <1347466008-7231-1-git-send-email-cyril@ti.com> <20120912203920.GU7677@google.com> In-Reply-To: <20120912203920.GU7677@google.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, davem@davemloft.net, eric.dumazet@gmail.com, hannes@cmpxchg.org, shangw@linux.vnet.ibm.com, vitalya@ti.com Hi Tejun, On 9/12/2012 4:39 PM, Tejun Heo wrote: > Hello, > > On Wed, Sep 12, 2012 at 12:06:48PM -0400, Cyril Chemparathy wrote: >> static void * __init alloc_bootmem_core(unsigned long size, >> unsigned long align, >> - unsigned long goal, >> - unsigned long limit) >> + phys_addr_t goal, >> + phys_addr_t limit) > > So, a function which takes phys_addr_t for goal and limit but returns > void * doesn't make much sense unless the function creates directly > addressable mapping somewhere. > On the 32-bit PAE platform in question, physical memory is located outside the 4GB range. Therefore phys_to_virt takes a 64-bit physical address and returns a 32-bit kernel mapped lowmem pointer. > The right thing to do would be converting to nobootmem (ie. memblock) > and use the memblock interface. Have no idea at all whether that > would be a realistic short-term solution for arm. > I must plead ignorance and let wiser souls chime in on ARM architecture plans w.r.t. nobootmem. As far as I can tell, the only thing that blocks us from using nobootmem at present is the need for sparsemem on some platforms. -- Thanks - Cyril -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org