Re: [PATCH 0/3] PCI: Rework config space locking, add INTx masking services

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Sep 12, 2011 at 06:54:01PM +0200, Jan Kiszka 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.
> 
> CC: Brian King <brking@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

For the series:

Acked-by: Michael S. Tsirkin <mst@redhat.com>


>  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