Re: [PATCH 1/2] nios2: Add architectural support for PCIe

Arnd Bergmann
2015-09-22T08:18:58Z

On Tuesday 22 September 2015 15:19:26 Ley Foon Tan wrote:
> +
> +config PCI_SYSCALL
> + def_bool PCI

IIRC, PCI_SYSCALL is deprecated and you should just leave that
turned off.

In any case, you enable the syscalls here but don't assign a
system call number, so that is rather pointless. I

I might be missing something though. Bjorn?

> @@ -14,7 +14,7 @@
> #include <linux/types.h>
> #include <asm/pgtable-bits.h>
>
> -/* PCI is not supported in nios2, set this to 0. */
> +/* PCI I/O space is not supported, set this to 0. */
> #define IO_SPACE_LIMIT 0
>
> #define readb_relaxed(addr) readb(addr)

It might be useful to enable this, just in case someone connects
a PCI host bridge that does support I/O space.

Which host bridge do you use? Are you sure there is no I/O space?
Most of them use a set of translation windows to set up a mapping
between bus address (memory, config and io space) and physical
(mmio) space.

> diff --git a/arch/nios2/include/asm/pci.h b/arch/nios2/include/asm/pci.h
> new file mode 100644
> index 0000000..f2cba05
> --- /dev/null
> +++ b/arch/nios2/include/asm/pci.h

What happens if you use the asm-generic header? If there is something
missing in it, we can try to get it to do the right things.

Arnd