From: Timur Tabi <timur.tabi@ammasso.com>
To: Gerd Knorr <kraxel@suse.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Will __pa(vmalloc()) ever work?
Date: Tue, 31 May 2005 10:51:27 -0500 [thread overview]
Message-ID: <429C87FF.5070003@ammasso.com> (raw)
In-Reply-To: <873bs5yrxj.fsf@bytesex.org>
Gerd Knorr wrote:
> You should use vmalloc_to_page() (this does the page-table walking
> with correct locking), then the usual dma mapping interface
> (pci_map_page() or pci_map_sg()) to get bus address(es) you can pass
> to your device for DMA.
My problem is that I don't know where the memory came from. It could have been allocated
via kmalloc, or vmalloc, or anywhere else. Can I call vmalloc_to_page() on memory
allocated via kmalloc()? If the answer is no, then how can I tell whether the memory was
allocated via vmalloc() or some other method? I need a reliable virtual-to-physical (or
virtual-to-bus, which is the same thing on x86 architectures) method for any memory address.
--
Timur Tabi
Staff Software Engineer
timur.tabi@ammasso.com
One thing a Southern boy will never say is,
"I don't think duct tape will fix it."
-- Ed Smylie, NASA engineer for Apollo 13
next prev parent reply other threads:[~2005-05-31 15:53 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-27 19:26 Will __pa(vmalloc()) ever work? Timur Tabi
2005-05-27 19:29 ` Christoph Hellwig
2005-05-27 19:54 ` Timur Tabi
2005-05-27 20:31 ` Arnd Bergmann
2005-05-28 16:16 ` Russell King
2005-05-30 9:38 ` Gerd Knorr
2005-05-31 15:51 ` Timur Tabi [this message]
2005-05-31 16:13 ` Gerd Knorr
2005-05-31 18:59 ` Timur Tabi
2005-05-31 20:01 ` Russell King
2005-05-31 20:44 ` Brian Gerst
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