lkml.org 
[lkml]   [2008]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: RFC: [PATCH] resource: ensure MMIO exclusivity for device drivers

* Arjan van de Ven <arjan@infradead.org> wrote:

>
> From: Arjan van de Ven <arjan@linux.intel.com>
> Date: Wed, 22 Oct 2008 19:55:31 -0700
> Subject: [PATCH] resource: ensure MMIO exclusivity for device drivers
>
> Device drivers that use pci_request_regions() (and similar APIs) have a
> reasonable expectation that they are the only ones accessing their device.
> As part of the e1000e hunt, we were afraid that some userland (X or some
> bootsplash stuff) was mapping the MMIO region that the driver thought it
> had exclusively via /dev/mem or via various sysfs resource mappings.
>
> This patch adds the option for device drivers to cause their reserved
> regions to be on the "banned from /dev/mem use" list, so now both kernel memory
> and device-exclusive MMIO regions are banned.
> NOTE: This is only active when CONFIG_STRICT_DEVMEM is set.
>
> In addition to the config option, a kernel parameter iomem=relaxed is
> provided for the cases where developers want to diagnose, in the field,
> drivers issues from userspace despite the drivers explicit request.
>
> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

the concept looks fine to me - the stricter we are in this area the
better IMO. Unless there are objections, i guess it's best to do this
via the PCI tree?

Ingo


\
 
 \ /
  Last update: 2008-10-27 16:35    [W:0.042 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site