Parallel probing (e.g. due to asynchronous probing) of devices that
share interrupts can currently result in two mappings for the same
hardware interrupt to be created.
    
This series adds a serialising mapping mutex so that looking for an
existing mapping before creating a new one is done atomically.

Included are also some related clean ups that remove a redundant lookup
for existing mappings and make the domain-association locking more fine
grained.

Johan


Changes in v2
 - split out redundant lookup cleanup (1/4)
 - use a per-domain mutex to address mapping race (2/4)
 - move kernel-doc to exported function (2/4)
 - fix association race (3/4, new)
 - use per-domain mutex for associations (4/4, new)


Johan Hovold (4):
  irqdomain: Look for existing mapping only once
  irqdomain: Fix mapping-creation race
  irqdomain: Fix domain-association race
  irqdomain: use per-domain mutex for associations

 include/linux/irqdomain.h |   2 +
 kernel/irq/irqdomain.c    | 104 ++++++++++++++++++++++++--------------
 2 files changed, 69 insertions(+), 37 deletions(-)

-- 
2.35.1