Date: Tue, 14 Jul 2009 15:30:50 +0000 From: Norbert Koch <nkoch@demig.de> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-hackers@freebsd.org Subject: Re: bus device driver Message-ID: <4A5CA4AA.6050307@demig.de> In-Reply-To: <200907140849.51702.jhb@freebsd.org> References: <4A5B3F1B.3040207@demig.de> <200907131435.30452.jhb@freebsd.org> <4A5C2EF8.3080208@demig.de> <200907140849.51702.jhb@freebsd.org>
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> From a hardware perspective, how do your devices know which addresses to > decode? Do they consume subranges of BARs or are they assigned fixed > addresses somehow? Do they have programmable decoders of some sort > themselves? If you wish to have the PCI bus assign you resources then that > implies that your PCI device has a BAR and that you want to request resources > for that BAR and then hand out subranges of that to your children. If that > is the case, then you will need to allocate the resources for the BAR for the > PCI device from the PCI bus. Then your bus driver for the PCI device will > need to suballoc from that BAR to your children devices. > > My device decodes one ram address range (16MB) and gives me one interrupt line. As my sub-devices operate on partial address areas my idea was to let them all call bus_alloc_resource() with the same rid parameter (= BAR selector) and different offsets. So the bookkeeping should be done by the pci driver, right?
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