Hi Hari, From: "ext Kanigeri, Hari" <h-kanigeri2@xxxxxx> Subject: RE: [RFC] dspbridge: staging todo list Date: Mon, 27 Apr 2009 05:05:38 +0200 > Hi, > > > This DMM feature should be replaced with "omap iommu" driver which > > commonly supports omap iommu feature. Currently it supports just a > > mapping of in-kernel buffers(contiguous/discontiguous), but will be > > extened to an user buffer soon. Anyway, "bitmap_find_free_region" > > would bring better performance if the number of VMAs becomes huge. > > > > -- DMM is dynamic memory mapping, where DSP VA is mapped to Physical > address of the buffers allocated by Multimedia applications. At > present, Bridge is using its own version of MMU module for mapping > the DSP VA to physical address, and this Bridge's MMU module can be > replaced with the omap iommu. But before we do that, following > things need to happen: > > - The iommu should reside in linux-omap tree :) Tony may keep it on one of the l-o branches. Anyway, I'll send them again to Russell. > - IOMMU module provides support for preservation of TLB > entries. Yes, it's necessary for the performance. > - IOMMU module provides support for notification of MMU > faults. Actually the mmu fault hander can be set by a client module, but at present, the registration interface is missing. I'll add this interface. > I did some basic sanity testing in Bridge by replacing the Bridge's > MMU module with the iommu module and the above items need to happen > before we migrate to use iommu. Thank you for your evaluation. I'll send the update version of iommu patchset soon. Hiroshi DOYU -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
