Re: [PATCH v3 0/6] ATS capability support for Intel IOMMU

[Grant Grundler <grundler@parisc-linux.org>]

On Thu, Feb 26, 2009 at 10:50:35AM +0800, Yu Zhao wrote:
...
> > Yu,
> > Can you please add something to Documentation/PCI/pci.txt?
> > New API I'm seeing are:
> > +extern int pci_enable_ats(struct pci_dev *dev, int ps);
> > +extern void pci_disable_ats(struct pci_dev *dev);
> > +extern int pci_ats_queue_depth(struct pci_dev *dev);
> 
> Yes, I'll document these new API.

Thank you! (But maybe this was a bad idea)

> > Do these also need to be EXPORT_SYMBOL_GPL() as well?
> > Or are drivers never expected to call the above?
> 
> PCI device driver shouldn't use these API, only IOMMU driver (can't be module)
> would use them. Anyway it's a good idea to export them :-)

No, it's not a good idea to export if only IOMMU drivers should use them.
Exporting the symbols can only lead to abuse.

In fact, my request to add them to pci.txt sounds like a bad idea.
I was thinking this was for device drivers.

In any case, documenting the API and intended use is good.
It's probably sufficient to add comments where the functions are defined.

thanks,
grant