Subject: Re: physically contiguous memory
To: None <firstname.lastname@example.org>
From: Marcus Comstedt <email@example.com>
Date: 03/26/2001 15:10:02
>>>>> "Lennart" == Lennart Augustsson <firstname.lastname@example.org> writes:
Lennart> Looking at your description above it sounds like you want the PCI board
Lennart> to be able to do DMA on the memory, so being contiguous is not the
Lennart> only requirement you have. For instance, you also need to find the
Lennart> "physical address" of the memory, and it has to be in an area that is
Lennart> DMAable. So bus_dma(9) looks like the right thing to me.
Lennart> uvm_pglistalloc() looks like it's on the totally wrong abstraction level.
Lennart> It's messing with memory at a far too low level.
Yes, for allocating memory for a DMA buffer for a PCI card, the
bus_dma functions of the PCI busspace should definitely be used. As
you say, this is _not_ the same thing as just allocating some
It's always so much easier when people actually explain what they are
trying to solve... :-9