On 07/31/10 - 11:18:05AM, Chris Wright wrote:
> > diff --git a/src/util/pci.c b/src/util/pci.c
> > index 26d55b8..f2890bd 100644
> > --- a/src/util/pci.c
> > +++ b/src/util/pci.c
> > @@ -283,6 +283,7 @@ pciIterDevices(pciIterPredicate predicate,
> > DIR *dir;
> > struct dirent *entry;
> > int ret = 0;
> > + int rc;
> >
> > *matched = NULL;
> >
> > @@ -322,11 +323,20 @@ pciIterDevices(pciIterPredicate predicate,
> > break;
> > }
> >
> > - if (predicate(dev, check, data)) {
> > + rc = predicate(dev, check, data);
> > + if (rc < 0) {
> > + /* the predicate returned an error, bail */
> > + pciFreeDevice(check);
> > + ret = -1;
> > + break;
> > + }
> > + else if (rc == 1) {
>
> CodingStyle?
>
> $ git grep "else {" | wc -l
> 1150
> $ git grep "else {" | grep -v } | wc -l
> 67
>
> Guess it's not unprecedented, just rare ;)
Heh, yeah, that's a habit of mine. libvirt does tend to do the other style
but *shrug*
>
> > VIR_DEBUG("%s %s: iter matched on %s", dev->id, dev->name, check->name);
> > *matched = check;
> > + ret = 1;
> > break;
> > }
> > +
> > pciFreeDevice(check);
> > }
> > closedir(dir);
> > @@ -510,10 +520,11 @@ pciBusContainsActiveDevices(pciDevice *dev,
> >
> > /* Is @check the parent of @dev ? */
> > static int
> > -pciIsParent(pciDevice *dev, pciDevice *check, void *data ATTRIBUTE_UNUSED)
> > +pciIsParent(pciDevice *dev, pciDevice *check, void *data)
> > {
> > uint16_t device_class;
> > uint8_t header_type, secondary, subordinate;
> > + pciDevice **best = data;
> >
> > if (dev->domain != check->domain)
> > return 0;
> > @@ -533,16 +544,54 @@ pciIsParent(pciDevice *dev, pciDevice *check, void *data ATTRIBUTE_UNUSED)
> >
> > VIR_DEBUG("%s %s: found parent device %s", dev->id, dev->name, check->name);
> >
> > - /* No, it's superman! */
> > - return (dev->bus >= secondary && dev->bus <= subordinate);
> > + /* if the secondary bus exactly equals the device's bus, then we found
> > + * the direct parent. No further work is necessary
> > + */
> > + if (dev->bus == secondary)
> > + return 1;
>
>
> > +
> > + /* otherwise, SRIOV allows VFs to be on different busses then their PFs.
> > + * In this case, what we need to do is look for the "best" match; i.e.
> > + * the most restrictive match that still satisfies all of the conditions.
> > + */
> > + if (dev->bus > secondary && dev->bus <= subordinate) {
> > + if (*best == NULL) {
> > + *best = pciGetDevice(check->domain, check->bus, check->slot,
> > + check->function);
> > + if (*best == NULL)
> > + return -1;
>
> too bad it's not refcounted, then we'd never hit a failure case here
Yeah, this is the part of the patch I'm least happy about, but this should
do the right thing.
>
> > + }
> > + else {
>
> CodingStyle?
>
> > + /* OK, we had already recorded a previous "best" match for the
> > + * parent. See if the current device is more restrictive than the
> > + * best, and if so, make it the new best
> > + */
> > + if (secondary > pciRead8(*best, PCI_SECONDARY_BUS)) {
>
> forgot it's not cached, at least this isn't a performance senstitive path
>
> > + pciFreeDevice(*best);
> > + *best = pciGetDevice(check->domain, check->bus, check->slot,
> > + check->function);
> > + if (*best == NULL)
> > + return -1;
> > + }
> > + }
> > + }
>
> Yes, should get the right match.
>
> > +
> > + return 0;
> > }
> >
> > -static pciDevice *
> > -pciGetParentDevice(pciDevice *dev)
> > +static int
> > +pciGetParentDevice(pciDevice *dev, pciDevice **parent)
> > {
> > - pciDevice *parent = NULL;
> > - pciIterDevices(pciIsParent, dev, &parent, NULL);
> > - return parent;
> > + pciDevice *best = NULL;
> > + int ret;
> > +
> > + *parent = NULL;
> > + ret = pciIterDevices(pciIsParent, dev, parent, &best);
> > + if (ret == 1)
> > + pciFreeDevice(best);
> > + else if (ret == 0)
> > + *parent = best;
> > + return ret;
>
> I think we could keep the old interface, but that's really just
> splitting hairs, and hey...you did the work already ;)
Well, I really need the "int" return value here to distinguish the error case,
which is why I ended up changing it here. It's an internal interface, so
I'm not too sad :).
>
> > }
> >
> > /* Secondary Bus Reset is our sledgehammer - it resets all
> > @@ -570,7 +619,8 @@ pciTrySecondaryBusReset(pciDevice *dev,
> > }
> >
> > /* Find the parent bus */
> > - parent = pciGetParentDevice(dev);
> > + if (pciGetParentDevice(dev, &parent) < 0)
> > + return -1;
> > if (!parent) {
> > pciReportError(VIR_ERR_NO_SUPPORT,
> > _("Failed to find parent device for %s"),
> > @@ -1377,7 +1427,8 @@ pciDeviceIsBehindSwitchLackingACS(pciDevice *dev)
> > {
> > pciDevice *parent;
> >
> > - parent = pciGetParentDevice(dev);
> > + if (pciGetParentDevice(dev, &parent) < 0)
> > + return -1;
> > if (!parent) {
> > /* if we have no parent, and this is the root bus, ACS doesn't come
> > * into play since devices on the root bus can't P2P without going
> > @@ -1400,6 +1451,7 @@ pciDeviceIsBehindSwitchLackingACS(pciDevice *dev)
> > do {
> > pciDevice *tmp;
> > int acs;
> > + int ret;
> >
> > acs = pciDeviceDownstreamLacksACS(parent);
> >
> > @@ -1412,8 +1464,10 @@ pciDeviceIsBehindSwitchLackingACS(pciDevice *dev)
> > }
> >
> > tmp = parent;
> > - parent = pciGetParentDevice(parent);
> > + ret = pciGetParentDevice(parent, &parent);
> > pciFreeDevice(tmp);
> > + if (ret < 0)
> > + return -1;
> > } while (parent);
> >
> > return 0;
>
> Acked-by: Chris Wright <chrisw@xxxxxxxxxx>
Thanks, I've pushed this now.
--
Chris Lalancette
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