From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 16 Aug 2000 11:24:23 -0700 Message-Id: <200008161824.LAA09497@pizda.ninka.net> From: "David S. Miller" In-reply-to: <20000816192012.K19260@redhat.com> (sct@redhat.com) Subject: Re: pte_pagenr/MAP_NR deleted in pre6 References: <399A4FE4.FA5C397A@augan.com> <200008161713.KAA54085@google.engr.sgi.com> <20000816192012.K19260@redhat.com> Sender: owner-linux-mm@kvack.org Return-Path: To: sct@redhat.com Cc: kanoj@google.engr.sgi.com, roman@augan.com, linux-mm@kvack.org, linux-kernel@vger.rutgers.edu, rmk@arm.linux.org.uk, nico@cam.org, davidm@hpl.hp.com, alan@lxorguk.ukuu.org.uk List-ID: Drivers which do DMA but only to <4GB addresses need bounce buffers. This is only true in an architecture specific sense (ie. x86 systems are the one's which have this particular restriction). Which is one of the reasons I wish the bounce buffer stuff went into the place it belongs, behind the pci_dma API. If we move to a page+offset model for drivers, we could do exactly this and also handle cases like ix86 PAE. Later, David S. Miller davem@redhat.com -- 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/