diff mbox series

clk: sp7021: Adjust width of _m in HWM_FIELD_PREP()

Message ID 20230501-sp7021-field_prep-warning-v1-1-5b36d71feefe@kernel.org (mailing list archive)
State Accepted, archived
Headers show
Series clk: sp7021: Adjust width of _m in HWM_FIELD_PREP() | expand

Commit Message

Nathan Chancellor May 1, 2023, 9:34 p.m. UTC
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@kernel.org>
---
 drivers/clk/clk-sp7021.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


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

Best regards,

Comments

Nathan Chancellor May 1, 2023, 9:37 p.m. UTC | #1
On Mon, May 01, 2023 at 02:34:47PM -0700, Nathan Chancellor wrote:
> 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.

Gah, I forgot:

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/202303221947.pXP2v4xJ-lkp@intel.com/

> Signed-off-by: Nathan Chancellor <nathan@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@kernel.org>
>
Nick Desaulniers May 1, 2023, 10:03 p.m. UTC | #2
On Mon, May 1, 2023 at 2:37 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On Mon, May 01, 2023 at 02:34:47PM -0700, Nathan Chancellor wrote:
> > 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

s/tyoes/types/

Thanks for the patch!

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Nathan, do you think anything can be done in FIELD_PREP or even
__BF_FIELD_CHECK using _Static_assert (or static_assert from
include/linux/build_bug.h) to help elucidate to developers that their
mask is too small?  I guess the line 71 of include/linux/bitfield.h
that is trying to warn via BUILD_BUG_ON is itself triggering a
-Wtautological-constant-out-of-range-compare warning that is perhaps
distracting from what the issue is?

If you're able to reproduce the issue locally still, does this seem to work?
```
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
index ebfa12f69501..762a27b5ae15 100644
--- a/include/linux/bitfield.h
+++ b/include/linux/bitfield.h
@@ -62,15 +62,15 @@

 #define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx)                      \
        ({                                                              \
+               static_assert(__bf_cast_unsigned(_mask, _mask) <=       \
+                             __bf_cast_unsigned(_reg, ~0ull),          \
+                             _pfx "type of reg too small for mask");   \
                BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask),          \
                                 _pfx "mask is not constant");          \
                BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero");    \
                BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?           \
                                 ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
                                 _pfx "value too large for the field"); \
-               BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
-                                __bf_cast_unsigned(_reg, ~0ull),       \
-                                _pfx "type of reg too small for mask"); \
                __BUILD_BUG_ON_NOT_POWER_OF_2((_mask) +                 \
                                              (1ULL << __bf_shf(_mask))); \
        })

```


> > 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.
>
> Gah, I forgot:
>
> Reported-by: kernel test robot <lkp@intel.com>
> Link: https://lore.kernel.org/202303221947.pXP2v4xJ-lkp@intel.com/
>
> > Signed-off-by: Nathan Chancellor <nathan@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@kernel.org>
> >
Nick Desaulniers May 1, 2023, 10:15 p.m. UTC | #3
On Mon, May 1, 2023 at 3:03 PM Nick Desaulniers <ndesaulniers@google.com> wrote:
>
> On Mon, May 1, 2023 at 2:37 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >
> > On Mon, May 01, 2023 at 02:34:47PM -0700, Nathan Chancellor wrote:
> > > 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
>
> s/tyoes/types/
>
> Thanks for the patch!
>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>
> Nathan, do you think anything can be done in FIELD_PREP or even
> __BF_FIELD_CHECK using _Static_assert (or static_assert from
> include/linux/build_bug.h) to help elucidate to developers that their
> mask is too small?  I guess the line 71 of include/linux/bitfield.h
> that is trying to warn via BUILD_BUG_ON is itself triggering a
> -Wtautological-constant-out-of-range-compare warning that is perhaps
> distracting from what the issue is?
>
> If you're able to reproduce the issue locally still, does this seem to work?
> ```
> diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
> index ebfa12f69501..762a27b5ae15 100644
> --- a/include/linux/bitfield.h
> +++ b/include/linux/bitfield.h
> @@ -62,15 +62,15 @@
>
>  #define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx)                      \
>         ({                                                              \
> +               static_assert(__bf_cast_unsigned(_mask, _mask) <=       \
> +                             __bf_cast_unsigned(_reg, ~0ull),          \
> +                             _pfx "type of reg too small for mask");   \
>                 BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask),          \
>                                  _pfx "mask is not constant");          \
>                 BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero");    \
>                 BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?           \
>                                  ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
>                                  _pfx "value too large for the field"); \
> -               BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
> -                                __bf_cast_unsigned(_reg, ~0ull),       \
> -                                _pfx "type of reg too small for mask"); \
>                 __BUILD_BUG_ON_NOT_POWER_OF_2((_mask) +                 \
>                                               (1ULL << __bf_shf(_mask))); \
>         })
>
> ```

Hmmm....maybe not:
```
drivers/gpu/drm/i915/i915_hwmon.c:97:14: error: static assertion
expression is not an integral constant expression
        reg_value = REG_FIELD_GET(field_msk, reg_value);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/i915/i915_reg_defs.h:87:44: note: expanded from
macro 'REG_FIELD_GET'
#define REG_FIELD_GET(__mask, __val)    ((u32)FIELD_GET(__mask, __val))
                                              ^~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/bitfield.h:154:3: note: expanded from macro 'FIELD_GET'
                __BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: ");       \
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/bitfield.h:65:17: note: expanded from macro '__BF_FIELD_CHECK'
                static_assert(__bf_cast_unsigned(_mask, _mask) <=       \
                ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/bitfield.h:61:70: note: expanded from macro '__bf_cast_unsigned'
#define __bf_cast_unsigned(type, x)     ((__unsigned_scalar_typeof(type))(x))
                                                                         ^
./include/linux/build_bug.h:77:50: note: expanded from macro 'static_assert'
#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
                                 ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:78:56: note: expanded from macro '__static_assert'
#define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
                                                       ^~~~
```
so there's probably a use of REG_FIELD_GET that is
__builtin_constant_p but not an integral constant expression. That's
too bad...

>
>
> > > 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.
> >
> > Gah, I forgot:
> >
> > Reported-by: kernel test robot <lkp@intel.com>
> > Link: https://lore.kernel.org/202303221947.pXP2v4xJ-lkp@intel.com/
> >
> > > Signed-off-by: Nathan Chancellor <nathan@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@kernel.org>
> > >
>
>
>
> --
> Thanks,
> ~Nick Desaulniers
Stephen Boyd May 3, 2023, 1:24 a.m. UTC | #4
Quoting Nathan Chancellor (2023-05-01 14:34:47)
> 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@kernel.org>
> ---

Applied to clk-next
diff mbox series

Patch

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);	\
 })