mm/memremap.c: convert devmap static branch to {inc,dec}
authorIra Weiny <ira.weiny@intel.com>
Tue, 13 Oct 2020 23:52:33 +0000 (16:52 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 14 Oct 2020 01:38:30 +0000 (18:38 -0700)
commit433e7d3177544c8cf0b6375abd310b0ef023fe9d
tree3afd4553d29a14577a9caa53caaca2b78de85156
parent822bca52ee7eb279acfba261a423ed7ac47d6f73
mm/memremap.c: convert devmap static branch to {inc,dec}

While reviewing Protection Key Supervisor support it was pointed out that
using a counter to track static branch enable was an anti-pattern which
was better solved using the provided static_branch_{inc,dec} functions.[1]

Fix up devmap_managed_key to work the same way.  Also this should be safer
because there is a very small (very unlikely) race when multiple callers
try to enable at the same time.

[1] https://lore.kernel.org/lkml/20200714194031.GI5523@worktop.programming.kicks-ass.net/

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lkml.kernel.org/r/20200810235319.2796597-1-ira.weiny@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/memremap.c