PageFault when I write in the Serial registers, MMU ?

PageFault when I write in the Serial registers, MMU ?

[Nicolas Mederle]

Hi,

    I am porting linux on a custom board equipped with a PPC750, and I 
will like to have some advices on the MMU. I used the powerpc arch, and 
I built my device tree.
    I will like to know in which files we can configure the 
authorizations access for the I/O registers. When I use the function 
md_ppc.progress, I have a data access fault. I modified the head. S 
files, for add the BAT config. But I think that it is not correct, and 
that it is possible to do it elsewhere (platform_init?). Moreover the 
kernel modify the MMU config, it removes the BATs, and configures the 
Registers Segments. So, must I remake the configuration? Or is it 
possible to indicate, at the beginning, which space is reserved for I/O?
    I studied several patch (sandpoint, PrPMC2800) but none configures 
really the MMU for I/O registers. In the same way, I read several books, 
but I am not able to have information that I seek, therefore I am really 
blocked. I warmly thank you for the assistance which you will be able to 
bring to me.

    Mapping :     0x0000 0000    ->  0x0FFF FFFF   :   RAM
                         0x2000 0000   ->   0x201F FFFF   :   ASIC ( 
UART, DMA, GPIO, PIC...)
                         0x8000 0000   ->   0x8FFF FFFF   :   PCI
                         0xF000 0000   ->   0xFFFF FFFF   :   Flash
    The kernel is load at 0x0, an the system is a Run In Memory. 
Currently, I don't use the flash.


Best regards,
Nicolas MEDERLE

-- 
Cordialement,

Nicolas MEDERLE. 

Re: PageFault when I write in the Serial registers, MMU ?

[Laurent Pinchart]

Hi Nicolas,

On Wednesday 11 July 2007 17:39, Nicolas Mederle wrote:
> Hi,
>
>     I am porting linux on a custom board equipped with a PPC750, and I
> will like to have some advices on the MMU. I used the powerpc arch, and
> I built my device tree.
>     I will like to know in which files we can configure the
> authorizations access for the I/O registers. When I use the function
> md_ppc.progress, I have a data access fault. I modified the head. S
> files, for add the BAT config. But I think that it is not correct, and
> that it is possible to do it elsewhere (platform_init?). Moreover the
> kernel modify the MMU config, it removes the BATs, and configures the
> Registers Segments. So, must I remake the configuration? Or is it
> possible to indicate, at the beginning, which space is reserved for I/O?
>     I studied several patch (sandpoint, PrPMC2800) but none configures
> really the MMU for I/O registers. In the same way, I read several books,
> but I am not able to have information that I seek, therefore I am really
> blocked. I warmly thank you for the assistance which you will be able to
> bring to me.
>
>     Mapping :     0x0000 0000    ->  0x0FFF FFFF   :   RAM
>                          0x2000 0000   ->   0x201F FFFF   :   ASIC (
> UART, DMA, GPIO, PIC...)
>                          0x8000 0000   ->   0x8FFF FFFF   :   PCI
>                          0xF000 0000   ->   0xFFFF FFFF   :   Flash
>     The kernel is load at 0x0, an the system is a Run In Memory.
> Currently, I don't use the flash.

You should ioremap() the memory you want to access, and use the I/O access 
functions defined in asm/io.h. Don't forget to iounmap() once you're done.

Best regards,

Laurent Pinchart

Re: PageFault when I write in the Serial registers, MMU ?

[Bhupender Saharan]

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Hi,

You could call *io_block_mapping* function from your setup.c file that will
add the entry into MMU.

regards
Bhupi





On 7/11/07, Nicolas Mederle <mederle_nicolas@yahoo.fr> wrote:
>
> Hi,
>
>    I am porting linux on a custom board equipped with a PPC750, and I
> will like to have some advices on the MMU. I used the powerpc arch, and
> I built my device tree.
>    I will like to know in which files we can configure the
> authorizations access for the I/O registers. When I use the function
> md_ppc.progress, I have a data access fault. I modified the head. S
> files, for add the BAT config. But I think that it is not correct, and
> that it is possible to do it elsewhere (platform_init?). Moreover the
> kernel modify the MMU config, it removes the BATs, and configures the
> Registers Segments. So, must I remake the configuration? Or is it
> possible to indicate, at the beginning, which space is reserved for I/O?
>    I studied several patch (sandpoint, PrPMC2800) but none configures
> really the MMU for I/O registers. In the same way, I read several books,
> but I am not able to have information that I seek, therefore I am really
> blocked. I warmly thank you for the assistance which you will be able to
> bring to me.
>
>    Mapping :     0x0000 0000    ->  0x0FFF FFFF   :   RAM
>                         0x2000 0000   ->   0x201F FFFF   :   ASIC (
> UART, DMA, GPIO, PIC...)
>                         0x8000 0000   ->   0x8FFF FFFF   :   PCI
>                         0xF000 0000   ->   0xFFFF FFFF   :   Flash
>    The kernel is load at 0x0, an the system is a Run In Memory.
> Currently, I don't use the flash.
>
>
> Best regards,
> Nicolas MEDERLE
>
> --
> Cordialement,
>
> Nicolas MEDERLE.
>
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>

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Re: PageFault when I write in the Serial registers, MMU ?

[Josh Boyer]

On Wed, 2007-07-11 at 09:32 -0700, Bhupender Saharan wrote:
> Hi,
>  
> You could call io_block_mapping function from your setup.c file that
> will add the entry into MMU.

io_block_mapping doesn't exist in the arch/powerpc tree.

josh