[PATCH] clk: sp7021: Adjust width of _m in HWM_FIELD_PREP()

[Nathan Chancellor]

When building with clang + W=1, there is a warning around an internal
comparison check within the FIELD_PREP() macro, due to a 32-bit variable
comparison against ~0ull:

  drivers/clk/clk-sp7021.c:316:8: error: result of comparison of constant 18446744073709551615 with expression of type 'typeof (_Generic((_m), ...' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
          r0 |= HWM_FIELD_PREP(MASK_SEL_FRA, clk->p[SEL_FRA]);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/clk/clk-sp7021.c:45:15: note: expanded from macro 'HWM_FIELD_PREP'
          (_m << 16) | FIELD_PREP(_m, value);     \
                       ^~~~~~~~~~~~~~~~~~~~~
  include/linux/bitfield.h:114:3: note: expanded from macro 'FIELD_PREP'
                  __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");    \
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/bitfield.h:71:53: note: expanded from macro '__BF_FIELD_CHECK'
                  BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
  note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
  include/linux/compiler_types.h:397:22: note: expanded from macro 'compiletime_assert'
          _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
          ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/compiler_types.h:385:23: note: expanded from macro '_compiletime_assert'
          __compiletime_assert(condition, msg, prefix, suffix)
          ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/compiler_types.h:377:9: note: expanded from macro '__compiletime_assert'
                  if (!(condition))                                       \
                        ^~~~~~~~~

This is expected given the tyoes of the input. Increase the size of the
temporary variable in HWM_FIELD_PREP() to eliminate the warning, which
follows the logic of commit cfd6fb45cfaf ("crypto: ccree - avoid
out-of-range warnings from clang") for the same reasons.

Signed-off-by: Nathan Chancellor <nathan at kernel.org>
---
 drivers/clk/clk-sp7021.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/clk-sp7021.c b/drivers/clk/clk-sp7021.c
index 8fec14120105..11d22043ddd7 100644
--- a/drivers/clk/clk-sp7021.c
+++ b/drivers/clk/clk-sp7021.c
@@ -41,7 +41,7 @@ enum {
 /* HIWORD_MASK FIELD_PREP */
 #define HWM_FIELD_PREP(mask, value)		\
 ({						\
-	u32 _m = mask;				\
+	u64 _m = mask;				\
 	(_m << 16) | FIELD_PREP(_m, value);	\
 })
 

---
base-commit: d54c1fd4a51e8fbc7f9da86b0cd338a4f7cd2bb2
change-id: 20230501-sp7021-field_prep-warning-223f17aeea8e

Best regards,
-- 
Nathan Chancellor <nathan at kernel.org>