Hi..
Just to add a note..
The kernel version i am referring to is 2.4.20.
On Thu, 2006-01-05 at 16:48, srikanth wrote:
> Hi all..
>
> I am working on a ixp425 up. I see that the
> __arch_ioremap function
> (in asm/arch/) is having a check for the pci region as below, which
> dis-allows io-remapping of the pci region.
>
> static inline void *
> __arch_ioremap(unsigned long phys_addr, size_t size, unsigned long
> flags)
> {
> extern void * __ioremap(unsigned long, size_t, unsigned long);
>
> if((phys_addr < 0x48000000) || (phys_addr > 0x4bffffff))
> return __ioremap(phys_addr, size, flags);
>
> return (void *)phys_addr;
> }
>
> Further, by the comments in the same file i understood that the ixp425
> has to
> access the pci region in a different way, but could not figure it out
> what does that mean exactly.
>
> These are the comments in the file
> /*
> * IXP425 does not have a transparent cpu -> PCI I/O translation
> * window. Instead, it has a set of registers that must be tweaked
> * with the proper byte lanes, command types, and address for the
> * transaction. This means that we need to override the default
> * I/O functions.
> */
>
> /*
> * IXP425 also does not have a transparent PCI MEM translation
> * window. For this reason, we have to use the NP registers for
> * all PCI mem acceses and have to implement custom
> * ioremap/unmap/etc functions. :( We need to check and make
> * sure that the address being accessed is a PCI address and
> * if not, fall back to the normal code.
> */
>
>
> Can anyone please explain what does this mean..
>
> Thanks in advance..
>
>
> Srikanth
>
>
>
>
> --
> Kernelnewbies: Help each other learn about the Linux kernel.
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--
Regards,
Srikanth.P
Development Engineer,
Banyan Networks,
(Broadband Division of
Midas Communications Pvt. Ltd.)
Chennai -India
GSM: +91-988-433-9-789
--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
FAQ: http://kernelnewbies.org/faq/
