SMP in 32-bit arch/powerpc

Is anybody else having problems with 32-bit SMP support in arch/powerpc?
I'm using 2.6.17 as my current base, because I've not yet merged the
latest mpic changes.

I'm currently bringing up a dual-7448 board, and when I build the kernel
with CONFIG_SMP, the bootmem allocator corrupts the device tree. The
strange thing is, this still happens when I don't start the second CPU.
Kernels built without CONFIG_SMP run flawlessly on the same hardware.

-- 
Adrian Cox [off-list ref]

On Wed, 2006-08-02 at 09:25 +0100, Adrian Cox wrote:

Is anybody else having problems with 32-bit SMP support in arch/powerpc?
I'm using 2.6.17 as my current base, because I've not yet merged the
latest mpic changes.

I'm currently bringing up a dual-7448 board, and when I build the kernel
with CONFIG_SMP, the bootmem allocator corrupts the device tree. The
strange thing is, this still happens when I don't start the second CPU.
Kernels built without CONFIG_SMP run flawlessly on the same hardware.

Seems to be working OK here:

fuego:~# uname -a
Linux fuego 2.6.17 #1 SMP Mon Jul 3 12:10:43 EST 2006 ppc GNU/Linux
fuego:~# cat /proc/cpuinfo
processor       : 0
cpu             : 604r
clock           : 332.000000MHz
revision        : 49.2 (pvr 0009 3102)
bogomips        : 82.68

processor       : 1
cpu             : 604r
clock           : 332.000000MHz
revision        : 49.2 (pvr 0009 3102)
bogomips        : 82.68

processor       : 2
cpu             : 604r
clock           : 332.000000MHz
revision        : 49.2 (pvr 0009 3102)
bogomips        : 82.68

processor       : 3
cpu             : 604r
clock           : 332.000000MHz
revision        : 49.2 (pvr 0009 3102)
bogomips        : 82.68

total bogomips  : 330.75
timebase        : 41500582
platform        : CHRP
machine         : CHRP IBM,7025-F50

cheers

-- 
Michael Ellerman
IBM OzLabs

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

Do you have more detailed descriptions? Our MPC8641D(dual-7448 core CPU)
board works well.

Best Regards,
Zhang Wei=20

-----Original Message-----
From: linuxppc-dev-bounces+wei.zhang=3Dfreescale.com@ozlabs.org=20
[mailto:linuxppc-dev-bounces+wei.zhang=3Dfreescale.com@ozlabs.or
g] On Behalf Of Adrian Cox
Sent: Wednesday, August 02, 2006 4:26 PM
To: linuxppc-dev@ozlabs.org
Subject: SMP in 32-bit arch/powerpc
=20
Is anybody else having problems with 32-bit SMP support in=20
arch/powerpc?
I'm using 2.6.17 as my current base, because I've not yet merged the
latest mpic changes.
=20
I'm currently bringing up a dual-7448 board, and when I build=20
the kernel
with CONFIG_SMP, the bootmem allocator corrupts the device tree. The
strange thing is, this still happens when I don't start the=20
second CPU.
Kernels built without CONFIG_SMP run flawlessly on the same hardware.
=20
--=20
Adrian Cox [off-list ref]
=20
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
=20

On Aug 2, 2006, at 3:25 AM, Adrian Cox wrote:

Is anybody else having problems with 32-bit SMP support in arch/ 
powerpc?
I'm using 2.6.17 as my current base, because I've not yet merged the
latest mpic changes.

I'm currently bringing up a dual-7448 board, and when I build the  
kernel
with CONFIG_SMP, the bootmem allocator corrupts the device tree. The
strange thing is, this still happens when I don't start the second  
CPU.
Kernels built without CONFIG_SMP run flawlessly on the same hardware.

There are a few patches to prom.c that may help.  I know I've run  
into this on other 32-bit systems booting from u-boot.  These patches  
resolved my issue.

* [PATCH] powerpc: Auto reserve of device tree blob
* [POWERPC] Prevent duplicate lmb reservations for Device...

- kumar

On Wed, 2006-08-02 at 08:32 -0500, Kumar Gala wrote:

On Aug 2, 2006, at 3:25 AM, Adrian Cox wrote:

quoted

Is anybody else having problems with 32-bit SMP support in arch/ 
powerpc?
I'm using 2.6.17 as my current base, because I've not yet merged the
latest mpic changes.

There are a few patches to prom.c that may help.  I know I've run  
into this on other 32-bit systems booting from u-boot.  These patches  
resolved my issue.
* [PATCH] powerpc: Auto reserve of device tree blob
* [POWERPC] Prevent duplicate lmb reservations for Device...

That was the problem. It now boots correctly, thanks.

-- 
Adrian Cox [off-list ref]