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. CC: Brian King <brk...@linux.vnet.ibm.com> Jan Kiszka (3): pci: Rework config space blocking services pci: Introduce INTx check & mask API uio: Convert uio_generic_pci to new intx masking API drivers/pci/access.c | 76 +++++++++++++++++---------- drivers/pci/iov.c | 12 ++-- drivers/pci/pci.c | 114 ++++++++++++++++++++++++++++++++++++++++- drivers/pci/pci.h | 2 + drivers/scsi/ipr.c | 66 +++++++++++++++++++++--- drivers/scsi/ipr.h | 1 + drivers/uio/uio_pci_generic.c | 82 +++--------------------------- include/linux/pci.h | 17 ++++-- 8 files changed, 248 insertions(+), 122 deletions(-) -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
