On Sun, Sep 26, 2010 at 02:46:51PM +0200, Michael S. Tsirkin wrote:
> > > > +static inline void pcie_aer_errmsg(PCIDevice *dev, const
> > > > PCIE_AERErrMsg *msg)
> > > > +{
> > > > + assert(pci_is_express(dev));
> > > > + assert(dev->exp.aer_errmsg);
> > > > + dev->exp.aer_errmsg(dev, msg);
> > >
> > > Why do we want the indirection? Why not have users just call the function?
> >
> > To handle error signaling uniformly.
> > Please see
> > 6.2.5. Sequence of Device Error Signaling and Logging Operations
> > and figure 6-2 and 6-3.
>
> My question was: the only difference appears to be between bridge and
> non-bridge devices: bridge has to do more stuff, but most code is
> common. So this seems to be a very roundabout way to do this.
> Can't we just have a common function with an if (bridge) statement up front?
> If we ever only expect 2 implementations, I think a function pointer
> is overkill.
Not 2, but 3. root port, upstream or downstream and normal device.
So you want something like the following?
More than 2 is a good reason for me, I prefer function pointer.
switch (pcie_cap_get_type(dev))
case PCI_EXP_TYPE_ROOT_PORT:
pcie_aer_errmsg_root_port();
break;
case PCI_EXP_TYPE_DOWNSTREAM:
case PCI_EXP_TYPE_UPSTREAM:
pcie_aer_errmsg_vbridge();
break;
default:
pcie_aer_errmsg_alldev();
break;
--
yamahata
