A limit in V2 for PCI setup

Greg Watson gwatson at lanl.gov
Tue Sep 30 14:45:00 CEST 2003


in V1 I used to call the pci ops directly, e.g.

extern pci_ops pci_direct;
pci_direct.read_dword(...);

Presumably this will work in V2 as well.

Greg


At 12:16 PM -0600 30/9/03, ron minnich wrote:
>In v2, it is pretty much impossible to do PCI setup BEFORE the PCI scan is
>called and device trees are built. Sometimes, however, you need to be able
>to work on PCI before the scan, e.g. to enable certain functions. I don't
>want this code in mainboard auto.c -- that's a bad way to go.
>
>See the below comment.
>
>/* we need to do things in this function so that PCI scan will find
>  * them.  One problem here is that we can't use ANY of the new device
>  * stuff. This work here precedes all that.     
>  * Fundamental problem with linuxbios V2 architecture.
>  * You can't do pci control in the C code without having done a PCI scan.
>  * But in some cases you need to to pci control in the c code before doing
>  * a PCI scan. But you can't use arch/romcc_io.h (the code you need)
>  * because
>  * that has functions with the same name but different type signatures
>  * (e.g. device_t is a struct in C code, and is an unsigned long in
>  * romcc code).
>  * This needs to get fixed. We need low-level pci scans
>  * in the C code.
>  */
>
>I think my fix is to make a copy of romcc_io.h, with different names and
>type signatures, for use by functions that need to work with PCI before
>the PCI scan has been done.
>
>comments welcome. I'll do this after lunch unless I hear strong
>counterarguments that will get me what I need.
>
>Thanks
>
>ron
>
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