Re: PCI extended configuration support

["Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost>]

On Mon, Sep 07, 2015 at 06:14:59PM +0900, Masanobu SAITOH wrote:
>  Hi, all.
> 
>  nonaka@ wrote code to access PCI extended configuration area.
> Currently, the diff supoorts only on x86.
> 
> 	http://ftp.netbsd.org/pub/NetBSD/misc/nonaka/tmp/nbsd-pci-extconf-support.diff
> 
> Is it OK to commit?

No.  There are multiple issues.

 - abuse of the pcitag_t  (I have patches that fix this.)

 - pci_conf_size() is unnecessary

 - too much ACPI dependence, there's nothing that says you have to use
   ACPI MCFG to get this information

 - possibility of too much KVA usage on 32-bit kernels

 - on-demand bus mapping may happen in inappropriate (interrupt) context

 - x86 bus_space_read/write functions do not use the %eax/ax/al register,
 as required by the AMD documentation for Family 10h's (and others) extended
 configuration space access.

	Jonathan Kollasch