Re: Unmapping pages from the linear addressing without HIGHMEM support
From: Gerhard Pircher <hidden>
Date: 2006-03-10 13:31:05
quoted hunk
--- Ursprüngliche Nachricht ---Von: Dan Malek [off-list ref] An: "Gerhard Pircher" [off-list ref] Kopie: debian-powerpc@lists.debian.org, linuxppc-dev@ozlabs.org, Benjamin Herrenschmidt [off-list ref] Betreff: Re: Unmapping pages from the linear addressing without HIGHMEM support Datum: Fri, 10 Mar 2006 07:59:33 -0500 On Mar 10, 2006, at 4:09 AM, Gerhard Pircher wrote:quoted
That would mean I cannot reuse the code in dma-mapping.c, right?Sure you can. All you need to do is turn of BAT mapping, which is as easy as using the 'nobats' command line parameter and all of this code should just work for you.
Yes, that was the solution I would have used. The other solution is to reserve a physical memory area for DMA operations that is not mapped by the BATs (AFAIU nor by any page tables setup by the kernel). Therefore I doubt that I can simply reuse the dma-mapping.c code for the latter approach!? Do I mix something up here?
quoted
... but I guess I have to setup my own page table for the reserved DMA memory area and implement my own alloc_pages() function!?No, that's already done for you behind all of these functions.
But only, if the whole BAT mapping is killed, right? Thanks! Gerhard -- "Feel free" mit GMX FreeMail! Monat für Monat 10 FreeSMS inklusive! http://www.gmx.net