Messages in this thread | | | Date | Mon, 27 Oct 2008 16:31:58 +0100 | From | Ingo Molnar <> | Subject | Re: RFC: [PATCH] resource: ensure MMIO exclusivity for device drivers |
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* 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
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