On 2011-10-06 17:48, Jesse Barnes wrote: > On Mon, 12 Sep 2011 18:54:01 +0200 > Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote: > >> This series tries to heal the currently broken locking scheme around PCI >> config space accesses. >> >> We have an interface lock out access via sysfs, but that service wrongly >> assumes it is only called by one instance at a time for some device. So >> two loops doing >> >> echo 1 > /sys/bus/pci/devices/<some-device>/reset >> >> in parallel will trigger a kernel BUG at the moment. >> >> Besides synchronizing with user space, we also need to manage config >> space access of generic PCI drivers. They need to mask legacy interrupt >> lines while the specific driver runs in user space or a guest OS. >> >> The approach taken here is provide mutex-like locking for general >> access - which still requires a special mechanism due to requirements of >> the IBM Power RAID SCSI driver. Furthermore, INTx masking is now >> available via the PCI core and synchronized via the internal pci_lock. >> >> Not sure who may want to take this, so I'm CC'ing broadly. > > ISTR a bunch of discussion about this (just back from lots of work > travel and vacation, sorry I missed most of it). > > Is this the agreed upon way of handling it? If so, can I get some > Reviewed/Acked-bys from people? I hope this is acceptable. These changes are required for further improvements of the KVM device assignment support (INTx sharing). So I would appreciate any ack or whatever feedback as well. Thanks, Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
