Re: ioremap() on SH

[Franck Bui-Huu <vagabon.xyz@gmail.com>]

Stuart MENEFY wrote:
> 0xa000 0000 is not a 'correct' physical address in 29 bit mode. In this
> example you should really be using physical 0. However traditionally
> the SH kernel allowed this because in 29 bit mode it is not ambiguous.
> 

Weird: why would a driver use 0xa000 0000 when it can simply use 0 ?
Isn't this error prone ?

Current implementation assumes that if the passed physical address is
greater than 0xc000 0000 then it uses page tables.

Why the 0xc000 0000 limit has been chosen ? Why not simply using the
512M limit ?

> In 32 bit mode this all changes. 0xa000 0000 is now a legitimate physical
> address, and needs to be mapped using the TLB or PMB. The current
> git kernel doesn't support ioremap for these addresses.
> 

Well if you just chose the 512M boundary it works for both world, this
is what I tried to propose in my previous email. And it removes the weid
test "PXSEG(phys) < P3SEG" too.

But I'm probably missing something since I'm not familiar with the SH
world.

		Franck