Re: virt_to_page/pci_map_page vs. pci_map_single

From: Ihar 'Philips' Filipau
Date: Tue Nov 04 2003 - 03:47:11 EST


Can any-one draw a conclusion?
Which function should be used in which case?

So this will be at least reflected in lkml archives ;-)

David S. Miller wrote:
On Mon, 3 Nov 2003 14:02:57 -0800
David Mosberger <davidm@xxxxxxxxxxxxxxxxx> wrote:

On 03 Nov 2003 09:17:59 -0500, Jes Sorensen <jes@xxxxxxxxxxxxxxxxxx> said:

Jes> Hmmm, my brain has gotten ia64ified ;-) It's basically the normal
Jes> mappings of the kernel, ie. the kernel text/data/bss segments as well
Jes> as anything you do not get back as a dynamic mapping such as
Jes> ioremap/vmalloc/kmap.

I don't think it's safe to use virt_to_page() on static kernel
addresses (text, data, and bss). For example, ia64 linux nowadays
uses a virtual mapping for the static kernel memory, so it's not part
of the identity-mapped segment.

That's correct and it'll break on sparc64 for similar reasons.

It's also not safe to do virt_to_page() on kernel stack addresses

Ihar 'Philips' Filipau / with best regards from Saarbruecken.
-- _ _ _
"... and for $64000 question, could you get yourself |_|*|_|
vaguely familiar with the notion of on-topic posting?" |_|_|*|
-- Al Viro @ LKML |*|*|*|

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at