padata: make padata_do_parallel find alternate callback CPU

padata_do_parallel currently returns -EINVAL if the callback CPU isn't
in the callback cpumask.

pcrypt tries to prevent this situation by keeping its own callback
cpumask in sync with padata's and checks that the callback CPU it passes
to padata is valid.  Make padata handle this instead.

padata_do_parallel now takes a pointer to the callback CPU and updates
it for the caller if an alternate CPU is used.  Overall behavior in
terms of which callback CPUs are chosen stays the same.

Prepares for removal of the padata cpumask notifier in pcrypt, which
will fix a lockdep complaint about nested acquisition of the CPU hotplug
lock later in the series.

Signed-off-by: Daniel Jordan <[email protected]>
Acked-by: Steffen Klassert <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Herbert Xu <[email protected]>

0 files changed, 0 insertions, 0 deletions