Date: Tue, 5 Jan 1999 10:24:33 +0000 (GMT) From: Doug Rabson <dfr@nlsystems.com> To: Garrett Wollman <wollman@khavrinen.lcs.mit.edu> Cc: Warner Losh <imp@village.org>, Bill Paul <wpaul@skynet.ctr.columbia.edu>, current@FreeBSD.ORG Subject: Re: bus_space_foo and bus_dmamap_foo Message-ID: <Pine.BSF.4.01.9901051017530.391-100000@herring.nlsystems.com> In-Reply-To: <199812312058.PAA07052@khavrinen.lcs.mit.edu>
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On Thu, 31 Dec 1998, Garrett Wollman wrote: > <<On Thu, 31 Dec 1998 13:43:50 -0700, Warner Losh <imp@village.org> said: > > > It was my understanding from talking to Justin that these areas were > > basically orthoginal. busspace and busdma are used to talk to the > > hardware, while DFR's new bus stuff is more a configuration thing > > rather than talking to the actual hardware. > > How you talk to the hardware depends on where it is in the > configuration graph. > > > How do you view this integration? I'm confused... What needs to be > > integrated? > > When you activate a memory or I/O resource, the appropriate magic > should happen such that included in the stuff you get back is > something which can be used to access that resource quickly. Stuff > like bus_space_alloc should be handled by the bus driver in > coordination with the resource manager. (It should be implemented as > a method call on the device's parent, so that it has all the necessary > context pre-computed.) I think that this is the right approach. The interface for PCI busses should have methods to manage the various device resources and these will be able to provide bus_space handles as necessary. The resources should not need to be mapped directly by the pci driver. I'm currently prototyping the new PCI interface (or I will be as soon as I can get that wretched sysinstall program working properly on the alpha) and I'll add something like this. Are there any manpages for bus_space and bus_dma in NetBSD which we can take? -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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