Devices with 36-bit paddr on 32-bit system

[Marcel Moolenaar]

> On Aug 24, 2015, at 11:44 PM, Justin Hibbits <jrh29 at alumni.cwru.edu> wrote:
> 
> With my work porting FreeBSD to PowerPC e500mc and e5500, I have
> devices in my device tree mapped well above the 4GB mark
> (0xffexxxxxx), and have no idea how to properly address them for
> resources in rman.  Do we already have a solution to support this?
> Part of the problem is the powerpc nexus does a straight convert to
> vm_offset_t of rman_get_start() (itself returning a u_long), and
> vm_offset_t is not necessarily equal to vm_paddr_t (on Book-E powerpc
> vm_offset_t is 32-bits, vm_paddr_t is 64-bits).

I think the best solution is to represent a resource address
space with a type other than u_long. It makes sense to have
it use bus_addr_t or vm_paddr_t for example. Such a change
comes at a high price for sure, but you’ll fix it once and
for all. I don’t think you should kluge your way out of this...

--
Marcel Moolenaar
marcel at xcllnt.net

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