question from linuxppc group

question from linuxppc group

[Jim Potter]

We have  a host bridge (plus PIC, mem ctlr, etc.) that is essentially
identical
for ppc and mips.  Where is the best place to put the code since we
don't want to
duplicate it for both architectures?

--
Sincerely,

Jim Potter
45th Parallel Processing
jrp@wvi.com

"It is rather for us to be here dedicated to the great
task remaining before us -- that from these honored dead
we take increased devotion to that cause for which they
gave the last full measure of devotion -- that we here
highly resolve that these dead shall not have died in vain,
that this nation under God shall have a new birth of
freedom, and that government of the people, by the people,
for the people shall not perish from the earth.

A. Lincoln, Gettysburg, 1863

ln -sf /dev/null /osama/bin/laden

Re: question from linuxppc group

[Benjamin Herrenschmidt]

>We have  a host bridge (plus PIC, mem ctlr, etc.) that is essentially
>identical
>for ppc and mips.  Where is the best place to put the code since we
>don't want to
>duplicate it for both architectures?

Well, most of the PCI & interrupt frameworks are mostly arch specific.
I can't tell for MIPS, but the way you setup a PCI host bridge on PPC
was written by me and Paulus without looking at MIPS. 

I don't think there is real need to have common code here. Maybe some
common definitions (register defs for example) could go into a linux/*.h
file.

Ben.

Re: question from linuxppc group

[Benjamin Herrenschmidt]

>We have  a host bridge (plus PIC, mem ctlr, etc.) that is essentially
>identical
>for ppc and mips.  Where is the best place to put the code since we
>don't want to
>duplicate it for both architectures?

Well, most of the PCI & interrupt frameworks are mostly arch specific.
I can't tell for MIPS, but the way you setup a PCI host bridge on PPC
was written by Paulus and me without looking at MIPS. 

I don't think there is real need to have common code here. Maybe some
common definitions (register defs for example) could go into a linux/*.h
file.

Ben.

Re: question from linuxppc group

[James Simmons]

> Well, most of the PCI & interrupt frameworks are mostly arch specific.
> I can't tell for MIPS, but the way you setup a PCI host bridge on PPC
> was written by me and Paulus without looking at MIPS. 

We toke the ideas from the PPC people and applied to the mips tree. Same
for the time code.

Re: question from linuxppc group

[Tom Rini]

On Tue, Sep 25, 2001 at 11:35:57PM +0200, Benjamin Herrenschmidt wrote:
> >We have  a host bridge (plus PIC, mem ctlr, etc.) that is essentially
> >identical
> >for ppc and mips.  Where is the best place to put the code since we
> >don't want to
> >duplicate it for both architectures?
> 
> Well, most of the PCI & interrupt frameworks are mostly arch specific.
> I can't tell for MIPS, but the way you setup a PCI host bridge on PPC
> was written by me and Paulus without looking at MIPS. 

Well, MIPS has been looking at us a bit I know.  Also, the patch that
Mark/Matt did uses the pci_auto stuff for setting up the bridges (iirc
thats what that code is for anyhow :)) and MIPS has been using that
as well of late, tho their gt64120 bits don't look like they use it
right now.

> I don't think there is real need to have common code here. Maybe some
> common definitions (register defs for example) could go into a linux/*.h
> file.

If nothing else, yeah.  And all of the drivers into drivers/.

-- 
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

Re: question from linuxppc group

[Eyal Lebedinsky]

Jim Potter wrote:
> 
> We have  a host bridge (plus PIC, mem ctlr, etc.) that is essentially
> identical
> for ppc and mips.  Where is the best place to put the code since we
> don't want to
> duplicate it for both architectures?

A common practice is to create a pseudo-arch directory, let's called
it 'shared' or 'common' and under it a directory for each component
that is shared. We can now have symbolic links for s shared file:
	arch/[mips|ppc]/pic.c -> arch/shared/pic-mippc.c

Or, for a shared subsystem 'pic1234'
	arch/[mips|ppc]/pic -> arch/shared/pic-mippc

One can even look at more similar archs and have
	arch/[mips|ppc]/pic -> arch/shared/mippc/pic
	arch/[mips|ppc]/mem -> arch/shared/mippc/mem

--
Eyal Lebedinsky (eyal@eyal.emu.id.au) <http://samba.anu.edu.au/eyal/>