Date: Thu, 09 Dec 2004 21:32:20 +0530 From: "Kamal R. Prasad" <kamalp@acm.org> To: John-Mark Gurney <gurney_j@resnet.uoregon.edu> Cc: freebsd-hackers@freebsd.org Subject: Re: mmap() Message-ID: <41B8770C.40707@acm.org> In-Reply-To: <20041208090504.GT19624@funkthat.com> References: <41B20B19.3090204@acm.org> <20041206025126.GO19624@funkthat.com> <41B3F24B.1000903@acm.org> <20041206074237.GP19624@funkthat.com> <41B5DF9B.50501@acm.org> <20041207221919.GQ19624@funkthat.com> <20041207222115.GA74736@freebie.xs4all.nl> <41B68DF5.6070708@acm.org> <20041208090504.GT19624@funkthat.com>
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John-Mark Gurney wrote: >Kamal R. Prasad wrote this message on Wed, Dec 08, 2004 at 10:45 +0530: > > >>Wilko Bulte wrote: >> >> >> >>>On Tue, Dec 07, 2004 at 02:19:19PM -0800, John-Mark Gurney wrote.. >>> >>> >>> >>>>Kamal R. Prasad wrote this message on Tue, Dec 07, 2004 at 22:21 +0530: >>>> >>>> >>>> >>>>>There was a bug in my interface routine which probably resulted in too >>>>>many calls. >>>>>Something like *paddr=vtophys(base) instead of >>>>>*paddr=vtophys(base+offset) should result in lots of calls to the >>>>>interface. >>>>> >>>>> >>>>> >>>>Just remeber that vtophys is not a supported interface in HEAD, (if it >>>>still works, it will probably be removed shortly).. Also, vtophys only >>>>works on limited archs, like i386 and alpha... >>>> >>>> >>>s/limited/some/ >>> >>> >>So what would be the equivalent supported interface in HEAD? >> >> > >bus_dma(9) It's a bit more complicated though... but with out it, >you won't be able to get your driver working on sparc64... > > > woudn't pmap_extract() provide me with a physical addr of the corresponding kernel virtual address? Also, is there some src code available that shows bus_dma can be used to share a block of memory between kernel and user space? My usb device probably doesn't have a dma controller, so I don't think the bulk pipe can use any memory allocated by bus_dma. [Pl. correct me if Im wrong this]. thanks -kamal >>BTW -man (4) usb probably needs more info than present. >> >> > >I'm sure it does, feel free to send-pr patches.. :) > > >
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