Date: Tue, 19 Feb 2002 21:38:14 -0800 (PST) From: Julian Elischer <julian@elischer.org> To: "M. Warner Losh" <imp@village.org> Cc: mike.varga@cavium.com, msmith@FreeBSD.ORG, freebsd-arch@FreeBSD.ORG Subject: Re: reverse vtophys() Message-ID: <Pine.BSF.4.21.0202192134200.60489-100000@InterJet.elischer.org> In-Reply-To: <20020219.211801.45873766.imp@village.org>
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Mike, How do you know the page is locked in memory? but more importantly, how do you know it is only mapped to a single address? we ar moving toward keeping a lot of pages unmapped and for DMA devices the need never be mapped for IO. they need onlybe mapped when copying data to serspace or when mmapping them. We'd need to know a much more specific reason to be able to give you the answer. I may have missed some of your posts. sorry if you already gave this information. Julian On Tue, 19 Feb 2002, M. Warner Losh wrote: > In message: <004f01c1b96b$a37d1f50$b210a8c0@netscreen5> > "mike varga" <mike.varga@cavium.com> writes: > : The concept is valid in Linux, > : there is a function that does > : what I am asking. > : bus_to_virtual(). > : > : The page is locked > : in memory. > : Therefor there is one valid page > : backed by the physical > : address that corresponds > : to the virtual address that > : I am interested in retrieving? > > If you have used the bus_space functions, you could use > rman_get_virtual(r), where r is a struct resource * that you got back > from bus_alloc_resource(). > > Warner > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-arch" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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