bitops: unify non-atomic bitops prototypes across architectures

Currently, there is a mess with the prototypes of the non-atomic
bitops across the different architectures:

ret	bool, int, unsigned long
nr	int, long, unsigned int, unsigned long
addr	volatile unsigned long *, volatile void *

Thankfully, it doesn't provoke any bugs, but can sometimes make
the compiler angry when it's not handy at all.
Adjust all the prototypes to the following standard:

ret	bool				retval can be only 0 or 1
nr	unsigned long			native; signed makes no sense
addr	volatile unsigned long *	bitmaps are arrays of ulongs

Next, some architectures don't define 'arch_' versions as they don't
support instrumentation, others do. To make sure there is always the
same set of callables present and to ease any potential future
changes, make them all follow the rule:
 * architecture-specific files define only 'arch_' versions;
 * non-prefixed versions can be defined only in asm-generic files;
and place the non-prefixed definitions into a new file in
asm-generic to be included by non-instrumented architectures.

Finally, add some static assertions in order to prevent people from
making a mess in this room again.
I also used the %__always_inline attribute consistently, so that
they always get resolved to the actual operations.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 7aaed501f768..87087454a288 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -26,12 +26,29 @@ extern unsigned int __sw_hweight16(unsigned int w);
 extern unsigned int __sw_hweight32(unsigned int w);
 extern unsigned long __sw_hweight64(__u64 w);
 
+#include <asm-generic/bitops/generic-non-atomic.h>
+
 /*
  * Include this here because some architectures need generic_ffs/fls in
  * scope
  */
 #include <asm/bitops.h>
 
+/* Check that the bitops prototypes are sane */
+#define __check_bitop_pr(name)						\
+	static_assert(__same_type(arch_##name, generic_##name) &&	\
+		      __same_type(name, generic_##name))
+
+__check_bitop_pr(__set_bit);
+__check_bitop_pr(__clear_bit);
+__check_bitop_pr(__change_bit);
+__check_bitop_pr(__test_and_set_bit);
+__check_bitop_pr(__test_and_clear_bit);
+__check_bitop_pr(__test_and_change_bit);
+__check_bitop_pr(test_bit);
+
+#undef __check_bitop_pr
+
 static inline int get_bitmask_order(unsigned int count)
 {
 	int order;