Re: [RFC PATCH net-next 02/10] net: hibmcge: Add read/write registers supported through the bar space

[Jijie Shao]

on 2024/8/5 20:55, Simon Horman wrote:
> Hi,
>
> I may well be wrong but I think that FIELD_PREP can only be used with
> a compile-time constant as the mask.
>
> In any case, with Clang-18 W=1 allmodconfig builds on x86_64 I see:

Thanks， I'll fix this warning in V2.

>    CC      drivers/net/ethernet/hisilicon/hibmcge/hbg_hw.o
>     CC      drivers/net/ethernet/hisilicon/hibmcge/hbg_main.o
> In file included from drivers/net/ethernet/hisilicon/hibmcge/hbg_main.c:8:
> drivers/net/ethernet/hisilicon/hibmcge/hbg_hw.h:31:15: warning: result of comparison of constant 18446744073709551615 with expression of type 'typeof (_Generic((mask), char: (unsigned char)0, unsigned char: (unsigned char)0, signed char: (unsigned char)0, unsigned short: (unsigned short)0, short: (unsigned short)0, unsigned int: (unsigned int)0, int: (unsigned int)0, unsigned long: (unsigned long)0, long: (unsigned long)0, unsigned long long: (unsigned long long)0, long long: (unsigned long long)0, default: (mask)))' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
>     31 |         reg_value |= FIELD_PREP(mask, val);
>        |                      ^~~~~~~~~~~~~~~~~~~~~
> ./include/linux/bitfield.h:115:3: note: expanded from macro 'FIELD_PREP'
>    115 |                 __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");    \
>        |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/bitfield.h:72:53: note: expanded from macro '__BF_FIELD_CHECK'
>     72 |                 BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
>        |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
>     73 |                                  __bf_cast_unsigned(_reg, ~0ull),       \
>        |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     74 |                                  _pfx "type of reg too small for mask"); \
>        |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/build_bug.h:39:58: note: expanded from macro 'BUILD_BUG_ON_MSG'
>     39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>        |                                     ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
> ././include/linux/compiler_types.h:510:22: note: expanded from macro 'compiletime_assert'
>    510 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
>        |         ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ././include/linux/compiler_types.h:498:23: note: expanded from macro '_compiletime_assert'
>    498 |         __compiletime_assert(condition, msg, prefix, suffix)
>        |         ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ././include/linux/compiler_types.h:490:9: note: expanded from macro '__compiletime_assert'
>    490 |                 if (!(condition))                                       \
>        |                       ^~~~~~~~~
> 1 warning generated.
> In file included from drivers/net/ethernet/hisilicon/hibmcge/hbg_hw.c:8:
> drivers/net/ethernet/hisilicon/hibmcge/hbg_hw.h:31:15: warning: result of comparison of constant 18446744073709551615 with expression of type 'typeof (_Generic((mask), char: (unsigned char)0, unsigned char: (unsigned char)0, signed char: (unsigned char)0, unsigned short: (unsigned short)0, short: (unsigned short)0, unsigned int: (unsigned int)0, int: (unsigned int)0, unsigned long: (unsigned long)0, long: (unsigned long)0, unsigned long long: (unsigned long long)0, long long: (unsigned long long)0, default: (mask)))' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
>     31 |         reg_value |= FIELD_PREP(mask, val);
>        |                      ^~~~~~~~~~~~~~~~~~~~~
> ./include/linux/bitfield.h:115:3: note: expanded from macro 'FIELD_PREP'
>    115 |                 __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");    \
>        |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/bitfield.h:72:53: note: expanded from macro '__BF_FIELD_CHECK'
>     72 |                 BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
>        |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
>     73 |                                  __bf_cast_unsigned(_reg, ~0ull),       \
>        |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     74 |                                  _pfx "type of reg too small for mask"); \
>        |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/build_bug.h:39:58: note: expanded from macro 'BUILD_BUG_ON_MSG'
>     39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>        |                                     ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
> ././include/linux/compiler_types.h:510:22: note: expanded from macro 'compiletime_assert'
>    510 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
>        |         ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ././include/linux/compiler_types.h:498:23: note: expanded from macro '_compiletime_assert'
>    498 |         __compiletime_assert(condition, msg, prefix, suffix)
>        |         ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ././include/linux/compiler_types.h:490:9: note: expanded from macro '__compiletime_assert'
>    490 |                 if (!(condition))                                       \
>        |                       ^~~~~~~~~
> 1 warning generated.
>
> ...