On 4/12/2019 11:38 AM, Leon Romanovsky wrote:
On Thu, Apr 11, 2019 at 07:07:42AM -0700, Dennis Dalessandro wrote:
From: Josh Collier <josh.d.collier@xxxxxxxxx>
Some kernels now enable CONFIG_IO_STRICT_DEVMEM
which prevents multiple handles to PCI resource0. In order
to continue to support expansion ROM updates while the
driver is loaded, the driver must now provide an interface
to control the expansion ROM write protection.
From this description, it seems like that CONFIG_IO_STRICT_DEVMEM was
added to prevent this type of access, doesn't it?
Due to the config option using the resource file is no longer an option
for manipulating the EPROM. There are some accesses that we want to be
able to make through the PCI config space which is not affected by the
above config option. However access to that is protected by the HW. So
this patch provides a safe interface to toggle that protection while
still preventing userspace from free range access to memory regions
claimed by the driver.
-Denny
