arm64: Silence sparse warnings caused by the type casting in (cmp)xchg

The arm64 xchg/cmpxchg() wrappers cast the arguments to (unsigned long)
prior to invoking the static inline functions implementing the
operation. Some restrictive type annotations (e.g. __bitwise) lead to
sparse warnings like below:

sparse warnings: (new ones prefixed by >>)
   fs/crypto/bio.c:67:17: sparse: sparse: cast from restricted blk_status_t
>> fs/crypto/bio.c:67:17: sparse: sparse: cast to restricted blk_status_t

Force the casting in the arm64 xchg/cmpxchg() wrappers to silence
sparse.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602230947.uNRsPyBn-lkp@intel.com/
Link: https://lore.kernel.org/r/202602230947.uNRsPyBn-lkp@intel.com/
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index d7a5407367414df69a898bef948f7c896778f38b..6cf3cd6873f5fec504d8e9a314ee4320ccce2890 100644 (file)
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -91,8 +91,9 @@ __XCHG_GEN(_mb)
 #define __xchg_wrapper(sfx, ptr, x)                                    \
 ({                                                                     \
        __typeof__(*(ptr)) __ret;                                       \
-       __ret = (__typeof__(*(ptr)))                                    \
-               __arch_xchg##sfx((unsigned long)(x), (ptr), sizeof(*(ptr))); \
+       __ret = (__force __typeof__(*(ptr)))                            \
+               __arch_xchg##sfx((__force unsigned long)(x), (ptr),     \
+                                 sizeof(*(ptr)));                      \
        __ret;                                                          \
 })
 
@@ -175,9 +176,10 @@ __CMPXCHG_GEN(_mb)
 #define __cmpxchg_wrapper(sfx, ptr, o, n)                              \
 ({                                                                     \
        __typeof__(*(ptr)) __ret;                                       \
-       __ret = (__typeof__(*(ptr)))                                    \
-               __cmpxchg##sfx((ptr), (unsigned long)(o),               \
-                               (unsigned long)(n), sizeof(*(ptr)));    \
+       __ret = (__force __typeof__(*(ptr)))                            \
+               __cmpxchg##sfx((ptr), (__force unsigned long)(o),       \
+                               (__force unsigned long)(n),             \
+                               sizeof(*(ptr)));                        \
        __ret;                                                          \
 })