Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261202AbVD3MEQ (ORCPT ); Sat, 30 Apr 2005 08:04:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261205AbVD3MEQ (ORCPT ); Sat, 30 Apr 2005 08:04:16 -0400 Received: from moutng.kundenserver.de ([212.227.126.183]:7390 "EHLO moutng.kundenserver.de") by vger.kernel.org with ESMTP id S261202AbVD3MEM (ORCPT ); Sat, 30 Apr 2005 08:04:12 -0400 To: =?iso-8859-1?Q?Paul_Mackerras?= Subject: =?iso-8859-1?Q?Re:_Re:_[PATCH_3/4]_ppc64:_Add_driver_for_BPA_iommu?= From: =?iso-8859-1?Q?Arnd_Bergmann?= Cc: =?iso-8859-1?Q?Arnd_Bergmann?= , =?iso-8859-1?Q?Benjamin_Herrenschmidt?= , =?iso-8859-1?Q?linuxppc64-dev?= , =?iso-8859-1?Q?Linux_Kernel_list?= , =?iso-8859-1?Q?Anton_Blanchard?= Message-Id: <26879984$111486195242737180269552.40594107@config8.schlund.de> X-Binford: 6100 (more power) X-Originating-From: 26879984 X-Mailer: Webmail X-Routing: DE Content-Type: text/plain; charset=US-ASCII Mime-Version: 1.0 Content-Transfer-Encoding: 7BIT X-Priority: 3 Date: Sat, 30 Apr 2005 14:02:02 +0200 X-Provags-ID: kundenserver.de abuse@kundenserver.de ident:@172.23.4.135 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1338 Lines: 32 Paul Mackerras schrieb am 29.04.2005, 15:06:54: > Arnd Bergmann writes: > > > Implementation of software load support for the BE iommu. This is very > > Could you expand a bit on what "software load support" is? Your > description is a bit terse. The Cell processor can put the I/O page table either in memory like the hashed page table (hardware load) or have the operating system write the entries into memory mapped CPU registers (software load). I use the software load mechanism because I know that all I/O page table entries for the amount of installed physical memory fit into the IO TLB cache. At the point when we get machines with more than 4GB of installed memory, we can either use hardware I/O page table access like the other platforms do or dynamically update the I/O TLB entries when a page fault occurs in the I/O subsystem. The software load can then use the macros that I have implemented for the static mapping in order to do the TLB cache updates. I'll make sure to add the description to the patches when I send them next time. Arnd <>< - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/