I don't understand. If we're going to differentiate MMCONFIG from some other
access mechanism, it only needs to be done at the Northbridge level. Devices
are electrically ignorant of the protocol used between CPU and Northbridge
to get the Northbridge to assert config cycles on the bus.
Agreed.
So we have Loic and Ivan's patch limiting MMCONFIG accesses to
offsets >= 256.
And we have Matthew's patch that abstracts the method for config
accesses to offsets < 256.
I beleive Matthew has already tested these patches for functionality
on x86. All that's needed is to test for regressions on other arches.
Is there any interest in providing the following?
1. The ability to use MMCONFIG for all accesses on systems that have
no problems with MMCONFIG.
2. For systems using both PCI and PCI express, testing each bus
for MMCONFIG compliance, to determine whether MMCONFIG can be
used for all config accesses or whether the bus must be limited
all to the method abstracted for offsets < 256.
Or does that introduce unnecessary complications?
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