Re: [Patch] PCI: check szhi when sz is 0 for 64 bit pref mem

[Eric W. Biederman]

Andrew Morton <akpm@xxxxxxxx> writes:

> On Fri, 3 Nov 2006 21:27:35 -0800
> "Yinghai Lu" <yinghai.lu@xxxxxxx> wrote:
>
>> For co-prcessor with mem installed, the ram will be treated to pref mem.
>
> What is "pref mem"?

Memory mapped base address registers can be either normal or for prefetchable
sections of memory mapped I/O.  Frequently all prefetchable bars are 64bit.
The prefetchable bars are also frequently ask for the largest amounts of
memory.  So it is easy and worthwhile to place all prefetchable bars about 4G.

The "pref mem" short hand comes from a the LinuxBIOS print statements that
report every bar value and what kind of bar it is, during boot up.

Eric
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