percpu: remove some sparse warnings

Make the following changes to remove some sparse warnings.

* Make DEFINE_PER_CPU_SECTION() declare __pcpu_unique_* before
  defining it.

* Annotate pcpu_extend_area_map() that it is entered with pcpu_lock
  held, releases it and then reacquires it.

* Make percpu related macros use unique nested variable names.

* While at it, add pcpu prefix to __size_call[_return]() macros as
  to-be-implemented sparse annotations will add percpu specific stuff
  to these macros.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 9bd03193ecd4..5a5d6ce4bd55 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -60,6 +60,7 @@
 
 #define DEFINE_PER_CPU_SECTION(type, name, sec)                         \
         __PCPU_DUMMY_ATTRS char __pcpu_scope_##name;                    \
+        extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name;            \
         __PCPU_DUMMY_ATTRS char __pcpu_unique_##name;                   \
         __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak                 \
         __typeof__(type) per_cpu__##name