Regarding MPC8641D

Regarding MPC8641D

[sivaji]

Hai,
            We have designed  a MPC8641D based AMC card. We are using the
kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1 Low Memory
offset mode the kernel was up and when we enable this core1 Low Memory
offset mode kernel was not up, It was hang after MPIC initialization.

Kerenl dump :          

# Booting image at 00200000 ...
  Image Name:   Linux-2.6.23-rc4-g5326152f-dirty
  Image Type:   PowerPC Linux Kernel Image (gzip compressed)
  Data Size:    4544816 Bytes =  4.3 MB
  Load Address: 00000000
  Entry Point:  00000000
  Verifying Checksum ... OK
  Uncompressing Kernel Image ... OK
  Booting using flat device tree at 0x700000
data:0
Probing machine type ...
 MPC86xx HPCN ...start c05d1e10 end c05d1ee0 <6>Using MPC86xx HPCN machine
description
Total memory = 600MB; using 2048kB for hash table (at cfe00000)
Linux version 2.6.23-rc4-g5326152f-dirty (root@sivaji) (gcc version 4.0.2
20060628 (Wasabi)) #45 SMP Wed Dec 5 12:01:58 IST 2007
console [udbg0] enabled
setup_arch: bootmem
mpc86xx_hpcn_setup_arch()
Found FSL PCI host bridge at 0x00000000f8008000.Firmware bus number: 0->254
MPC86xx HPCN board from Freescale Semiconductor
arch: exit
Zone PFN ranges:
 DMA             0 ->   153600
 Normal     153600 ->   153600
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
   0:        0 ->   153600
Built 1 zonelists in Zone order.  Total pages: 152400
Kernel command line: root=/dev/ram console=ttyS0,115200 mem=600M
mpic: Setting up MPIC " MPIC     " version 1.2 at f8040000, max 2 CPUs
mpic: ISU size: 88, shift: 7, mask: 7f
mpic: Initializing for 88 sources
PID hash table entries: 4096 (order: 12, 16384 bytes)
Console: colour dummy device 80x25
Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
Memory: 600064k/614400k available (5832k kernel code, 14096k reserved, 116k
data, 233k bss, 3244k init)
SLUB: Genslabs=22, HWalign=32, Order=0-1, MinObjects=4, CPUs=2, Nodes=1
Security Framework v1.0.0 initialized
SELinux:  Initializing.
selinux_register_security:  Registering secondary module capability
Capability LSM initialized as secondary
Mount-cache hash table entries: 512
mpic: requesting IPIs ...

                     After this the kernel was hang, i want to know why
kernel was hang when we enalbe Low memory Offset mode. Please help me to fix
this issue.
Thanks and Regards
Sivaji
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Re: Regarding MPC8641D

[Christopher Fester]

[-- Attachment #1: Type: text/plain, Size: 799 bytes --]

On Tue, 2007-12-04 at 23:51 -0800, sivaji wrote:
>             We have designed  a MPC8641D based AMC card. We are using the
> kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1 Low Memory
> offset mode the kernel was up and when we enable this core1 Low Memory
> offset mode kernel was not up, It was hang after MPIC initialization.
[snip!]
>                      After this the kernel was hang, i want to know why
> kernel was hang when we enalbe Low memory Offset mode. Please help me to fix
> this issue.

Have you compiled your kernel for SMP mode?  I believe the Low memory
offset mode is only for AMP mode (vxworks can use this, probably other
OSes).  I don't know if the kernel has support for any multiprocessing
mode other than SMP.

Hope that helps,
Chris

[-- Attachment #2: Type: text/html, Size: 1438 bytes --]

Re: Regarding MPC8641D

[sivaji]

Hai,
             The kernel was compiled in SMP mode. The low memory offset mode
is only for AMP mode means, then how we test both the core 0 and 1 in the
linux kernel ?. Asper my understanding if we enable the Low Memory Offset
mode, then only the core1 translation is enabled. If we disalbed the Low
Memory offset mode, Only Core 0  will work in SMP mode and Core 1 will idle.
If we want to test the efficient of Dual core means we need to enable both
the core and Low Memory Offset Mode. For this configuration linux kernel was
not up.
( Please correct me if I am wrong )

Thanks and Regards
Sivaji


Chris Fester wrote:
> 
> On Tue, 2007-12-04 at 23:51 -0800, sivaji wrote:
>>             We have designed  a MPC8641D based AMC card. We are using the
>> kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1 Low
>> Memory
>> offset mode the kernel was up and when we enable this core1 Low Memory
>> offset mode kernel was not up, It was hang after MPIC initialization.
> [snip!]
>>                      After this the kernel was hang, i want to know why
>> kernel was hang when we enalbe Low memory Offset mode. Please help me to
>> fix
>> this issue.
> 
> Have you compiled your kernel for SMP mode?  I believe the Low memory
> offset mode is only for AMP mode (vxworks can use this, probably other
> OSes).  I don't know if the kernel has support for any multiprocessing
> mode other than SMP.
> 
> Hope that helps,
> Chris
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
> 

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Regarding MPC8641D

[Siva Prasad]

Hi,

If you want to use SMP, do not enable low memory offset mode. That is
only and only for AMP, not for SMP. All the exception vectors go into a
different address range for core1, once you enable that, resulting in a
need for entirely different copy of OS (be it Linux, or any other OS).

You are in the right path. Just don't enable low memory offset mode,
unless you are looking for Assymetric multi-processing.

- siva




Message: 6
Date: Wed, 5 Dec 2007 16:45:31 -0800 (PST)
From: sivaji <rameshmrm@gmail.com>
Subject: Re: Regarding MPC8641D
To: linuxppc-dev@ozlabs.org
Message-ID: <14184234.post@talk.nabble.com>
Content-Type: text/plain; charset=3Dus-ascii


Hai,
             The kernel was compiled in SMP mode. The low memory offset
mode
is only for AMP mode means, then how we test both the core 0 and 1 in
the
linux kernel ?. Asper my understanding if we enable the Low Memory
Offset
mode, then only the core1 translation is enabled. If we disalbed the Low
Memory offset mode, Only Core 0  will work in SMP mode and Core 1 will
idle.
If we want to test the efficient of Dual core means we need to enable
both
the core and Low Memory Offset Mode. For this configuration linux kernel
was
not up.
( Please correct me if I am wrong )

Thanks and Regards
Sivaji


Chris Fester wrote:
>=20
> On Tue, 2007-12-04 at 23:51 -0800, sivaji wrote:
>>             We have designed  a MPC8641D based AMC card. We are using
the
>> kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1 Low
>> Memory
>> offset mode the kernel was up and when we enable this core1 Low
Memory
>> offset mode kernel was not up, It was hang after MPIC initialization.
> [snip!]
>>                      After this the kernel was hang, i want to know
why
>> kernel was hang when we enalbe Low memory Offset mode. Please help me
to
>> fix
>> this issue.
>=20
> Have you compiled your kernel for SMP mode?  I believe the Low memory
> offset mode is only for AMP mode (vxworks can use this, probably other
> OSes).  I don't know if the kernel has support for any multiprocessing
> mode other than SMP.
>=20
> Hope that helps,
> Chris
>=20

RE: Regarding MPC8641D

[Siva Prasad]

BTW... it is not true that core1 is idle when low memory offset mode is
disabled. Taking core1 out of reset will enable core1 to start booting.
These two are two different things.

- Siva



-----Original Message-----
From: Siva Prasad=20
Sent: Wednesday, December 05, 2007 5:06 PM
To: 'linuxppc-dev@ozlabs.org'
Cc: 'rameshmrm@gmail.com'
Subject: Regarding MPC8641D

Hi,

If you want to use SMP, do not enable low memory offset mode. That is
only and only for AMP, not for SMP. All the exception vectors go into a
different address range for core1, once you enable that, resulting in a
need for entirely different copy of OS (be it Linux, or any other OS).

You are in the right path. Just don't enable low memory offset mode,
unless you are looking for Assymetric multi-processing.

- siva




Message: 6
Date: Wed, 5 Dec 2007 16:45:31 -0800 (PST)
From: sivaji <rameshmrm@gmail.com>
Subject: Re: Regarding MPC8641D
To: linuxppc-dev@ozlabs.org
Message-ID: <14184234.post@talk.nabble.com>
Content-Type: text/plain; charset=3Dus-ascii


Hai,
             The kernel was compiled in SMP mode. The low memory offset
mode
is only for AMP mode means, then how we test both the core 0 and 1 in
the
linux kernel ?. Asper my understanding if we enable the Low Memory
Offset
mode, then only the core1 translation is enabled. If we disalbed the Low
Memory offset mode, Only Core 0  will work in SMP mode and Core 1 will
idle.
If we want to test the efficient of Dual core means we need to enable
both
the core and Low Memory Offset Mode. For this configuration linux kernel
was
not up.
( Please correct me if I am wrong )

Thanks and Regards
Sivaji


Chris Fester wrote:
>=20
> On Tue, 2007-12-04 at 23:51 -0800, sivaji wrote:
>>             We have designed  a MPC8641D based AMC card. We are using
the
>> kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1 Low
>> Memory
>> offset mode the kernel was up and when we enable this core1 Low
Memory
>> offset mode kernel was not up, It was hang after MPIC initialization.
> [snip!]
>>                      After this the kernel was hang, i want to know
why
>> kernel was hang when we enalbe Low memory Offset mode. Please help me
to
>> fix
>> this issue.
>=20
> Have you compiled your kernel for SMP mode?  I believe the Low memory
> offset mode is only for AMP mode (vxworks can use this, probably other
> OSes).  I don't know if the kernel has support for any multiprocessing
> mode other than SMP.
>=20
> Hope that helps,
> Chris
>=20

Re: Regarding MPC8641D

[sivaji]

Hi,
           We need only SMP mode, asper ur idea let me disable the Low
memory offset mode. We face some issues when ioremap in the kernel, we guess
the problem is related to Low memory offset mode so only we go for that.
Consider now the Low memory offset is disable the bootargs (root=/dev/ram
console=ttyS0, mem=504M). When mem=504 or greater than  we are not able to
ioremap, if mem is less than 500 there was no issues on ioremap. We can't
understand why ioremap was failed for 504M?

Thanks and Regards
S.Balamurugan


Siva Prasad-3 wrote:
> 
> Hi,
> 
> If you want to use SMP, do not enable low memory offset mode. That is
> only and only for AMP, not for SMP. All the exception vectors go into a
> different address range for core1, once you enable that, resulting in a
> need for entirely different copy of OS (be it Linux, or any other OS).
> 
> You are in the right path. Just don't enable low memory offset mode,
> unless you are looking for Assymetric multi-processing.
> 
> - siva
> 
> 
> 
> 
> Message: 6
> Date: Wed, 5 Dec 2007 16:45:31 -0800 (PST)
> From: sivaji <rameshmrm@gmail.com>
> Subject: Re: Regarding MPC8641D
> To: linuxppc-dev@ozlabs.org
> Message-ID: <14184234.post@talk.nabble.com>
> Content-Type: text/plain; charset=us-ascii
> 
> 
> Hai,
>              The kernel was compiled in SMP mode. The low memory offset
> mode
> is only for AMP mode means, then how we test both the core 0 and 1 in
> the
> linux kernel ?. Asper my understanding if we enable the Low Memory
> Offset
> mode, then only the core1 translation is enabled. If we disalbed the Low
> Memory offset mode, Only Core 0  will work in SMP mode and Core 1 will
> idle.
> If we want to test the efficient of Dual core means we need to enable
> both
> the core and Low Memory Offset Mode. For this configuration linux kernel
> was
> not up.
> ( Please correct me if I am wrong )
> 
> Thanks and Regards
> Sivaji
> 
> 
> Chris Fester wrote:
>> 
>> On Tue, 2007-12-04 at 23:51 -0800, sivaji wrote:
>>>             We have designed  a MPC8641D based AMC card. We are using
> the
>>> kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1 Low
>>> Memory
>>> offset mode the kernel was up and when we enable this core1 Low
> Memory
>>> offset mode kernel was not up, It was hang after MPIC initialization.
>> [snip!]
>>>                      After this the kernel was hang, i want to know
> why
>>> kernel was hang when we enalbe Low memory Offset mode. Please help me
> to
>>> fix
>>> this issue.
>> 
>> Have you compiled your kernel for SMP mode?  I believe the Low memory
>> offset mode is only for AMP mode (vxworks can use this, probably other
>> OSes).  I don't know if the kernel has support for any multiprocessing
>> mode other than SMP.
>> 
>> Hope that helps,
>> Chris
>> 
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
> 
> 

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Regarding MPC8641D

[Siva Prasad]

Hello Bala,

I don't think the ioremap issues are related with low memory offset
mode. But again, I am not sure if you (system by default does not do it)
are reserving that area (from 256 to 512 which is low memory offset
region). Further, where do you get this 504 number specifically?

If you want, I can try out your code on my 8641D board.

Thanks
Siva


Date: Wed, 5 Dec 2007 17:45:01 -0800 (PST)
From: sivaji <rameshmrm@gmail.com>
Subject: Re: Regarding MPC8641D
To: linuxppc-dev@ozlabs.org
Message-ID: <14184891.post@talk.nabble.com>
Content-Type: text/plain; charset=3Dus-ascii


Hi,
           We need only SMP mode, asper ur idea let me disable the Low
memory offset mode. We face some issues when ioremap in the kernel, we
guess
the problem is related to Low memory offset mode so only we go for that.
Consider now the Low memory offset is disable the bootargs
(root=3D/dev/ram
console=3DttyS0, mem=3D504M). When mem=3D504 or greater than  we are not =
able
to
ioremap, if mem is less than 500 there was no issues on ioremap. We
can't
understand why ioremap was failed for 504M?

Thanks and Regards
S.Balamurugan


Siva Prasad-3 wrote:
>=20
> Hi,
>=20
> If you want to use SMP, do not enable low memory offset mode. That is
> only and only for AMP, not for SMP. All the exception vectors go into
a
> different address range for core1, once you enable that, resulting in
a
> need for entirely different copy of OS (be it Linux, or any other OS).
>=20
> You are in the right path. Just don't enable low memory offset mode,
> unless you are looking for Assymetric multi-processing.
>=20
> - siva
>=20
>=20
>=20
>=20
> Message: 6
> Date: Wed, 5 Dec 2007 16:45:31 -0800 (PST)
> From: sivaji <rameshmrm@gmail.com>
> Subject: Re: Regarding MPC8641D
> To: linuxppc-dev@ozlabs.org
> Message-ID: <14184234.post@talk.nabble.com>
> Content-Type: text/plain; charset=3Dus-ascii
>=20
>=20
> Hai,
>              The kernel was compiled in SMP mode. The low memory
offset
> mode
> is only for AMP mode means, then how we test both the core 0 and 1 in
> the
> linux kernel ?. Asper my understanding if we enable the Low Memory
> Offset
> mode, then only the core1 translation is enabled. If we disalbed the
Low
> Memory offset mode, Only Core 0  will work in SMP mode and Core 1 will
> idle.
> If we want to test the efficient of Dual core means we need to enable
> both
> the core and Low Memory Offset Mode. For this configuration linux
kernel
> was
> not up.
> ( Please correct me if I am wrong )
>=20
> Thanks and Regards
> Sivaji
>=20
>=20
> Chris Fester wrote:
>>=20
>> On Tue, 2007-12-04 at 23:51 -0800, sivaji wrote:
>>>             We have designed  a MPC8641D based AMC card. We are
using
> the
>>> kernel (2.6.23-rc4) and uboot (1.2.0).  When we disable the core1
Low
>>> Memory
>>> offset mode the kernel was up and when we enable this core1 Low
> Memory
>>> offset mode kernel was not up, It was hang after MPIC
initialization.
>> [snip!]
>>>                      After this the kernel was hang, i want to know
> why
>>> kernel was hang when we enalbe Low memory Offset mode. Please help
me
> to
>>> fix
>>> this issue.
>>=20
>> Have you compiled your kernel for SMP mode?  I believe the Low memory
>> offset mode is only for AMP mode (vxworks can use this, probably
other
>> OSes).  I don't know if the kernel has support for any
multiprocessing
>> mode other than SMP.
>>=20
>> Hope that helps,
>> Chris
>>=20
>=20
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>=20
>=20