From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A70747F.2010305@valinux.com> Date: Thu, 25 Jan 2001 11:46:23 -0700 From: Jeff Hartmann MIME-Version: 1.0 Subject: Re: ioremap_nocache problem? References: <3A6D5D28.C132D416@sangate.com> <20010123165117Z131182-221+34@kanga.kvack.org> <20010123165117Z131182-221+34@kanga.kvack.org> ; from ttabi@interactivesi.com on Tue, Jan 23, 2001 at 10:53:51AM -0600 <20010125155345Z131181-221+38@kanga.kvack.org> <20010125165001Z132264-460+11@vger.kernel.org> <20010125175308Z130507-460+45@vger.kernel.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Timur Tabi Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Timur Tabi wrote: > ** Reply to message from Jeff Hartmann on Thu, 25 Jan > 2001 11:13:35 -0700 > > > >> You need to have your driver in the early bootup process then. When >> memory is being detected (but before the free lists are created.), you >> can set your page as being reserved. > > > But doesn't this mean that my driver has to be built as part of the kernel? > The end-user won't have the source code, so he won't be able to compile it, only > link it. As it stands now, our driver is a binary that can be shipped > separately. Sorry, this is the only way to do it properly. Binary kernel drivers are intensely evil. ;) Open the driver and you have no problems. You also do know that binary kernel drivers mean you'll be chasing every kernel release, having to provide several different flavors of your binary depending on the users kernel configuration. It also means that when kernel interfaces change, people won't be nice and change your code over to the new interfaces for you. For instance if a function depreciates, your code might be automatically moved to use the replacement function if your in the standard kernel. If your a binary module, you have to do all that maintaining yourself. (There are several other reasons to have open kernel modules. I won't go into the entire argument, since that could take all day.) You might be able to get away with making detection of this page open, and keep the rest of the driver closed. However that is something for Linus to decided, not I. I believe he doesn't like putting in hooks in the kernel for binary modules. Since all you really want to do is reserve the page during early bootup, perhaps he might let you get away with it. Not my call though. -Jeff -- 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.eu.org/Linux-MM/