diff options
Diffstat (limited to 'drivers/net/sfc/base/efx_types.h')
| -rw-r--r-- | drivers/net/sfc/base/efx_types.h | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/drivers/net/sfc/base/efx_types.h b/drivers/net/sfc/base/efx_types.h index 0581f67f..65168ab7 100644 --- a/drivers/net/sfc/base/efx_types.h +++ b/drivers/net/sfc/base/efx_types.h @@ -329,6 +329,16 @@ extern int fix_lint; #endif /* + * Saturation arithmetic subtract with minimum equal to zero. + * + * Use saturating arithmetic to ensure a non-negative result. This + * avoids undefined behaviour (and compiler warnings) when used as a + * shift count. + */ +#define EFX_SSUB(_val, _sub) \ + ((_val) > (_sub) ? ((_val) - (_sub)) : 0) + +/* * Extract bit field portion [low,high) from the native-endian element * which contains bits [min,max). * @@ -347,8 +357,8 @@ extern int fix_lint; ((FIX_LINT(_low > _max) || FIX_LINT(_high < _min)) ? \ 0U : \ ((_low > _min) ? \ - ((_element) >> (_low - _min)) : \ - ((_element) << (_min - _low)))) + ((_element) >> EFX_SSUB(_low, _min)) : \ + ((_element) << EFX_SSUB(_min, _low)))) /* * Extract bit field portion [low,high) from the 64-bit little-endian @@ -537,29 +547,29 @@ extern int fix_lint; (((_low > _max) || (_high < _min)) ? \ 0U : \ ((_low > _min) ? \ - (((uint64_t)(_value)) << (_low - _min)) : \ - (((uint64_t)(_value)) >> (_min - _low)))) + (((uint64_t)(_value)) << EFX_SSUB(_low, _min)) :\ + (((uint64_t)(_value)) >> EFX_SSUB(_min, _low)))) #define EFX_INSERT_NATIVE32(_min, _max, _low, _high, _value) \ (((_low > _max) || (_high < _min)) ? \ 0U : \ ((_low > _min) ? \ - (((uint32_t)(_value)) << (_low - _min)) : \ - (((uint32_t)(_value)) >> (_min - _low)))) + (((uint32_t)(_value)) << EFX_SSUB(_low, _min)) :\ + (((uint32_t)(_value)) >> EFX_SSUB(_min, _low)))) #define EFX_INSERT_NATIVE16(_min, _max, _low, _high, _value) \ (((_low > _max) || (_high < _min)) ? \ 0U : \ (uint16_t)((_low > _min) ? \ - ((_value) << (_low - _min)) : \ - ((_value) >> (_min - _low)))) + ((_value) << EFX_SSUB(_low, _min)) : \ + ((_value) >> EFX_SSUB(_min, _low)))) #define EFX_INSERT_NATIVE8(_min, _max, _low, _high, _value) \ (((_low > _max) || (_high < _min)) ? \ 0U : \ (uint8_t)((_low > _min) ? \ - ((_value) << (_low - _min)) : \ - ((_value) >> (_min - _low)))) + ((_value) << EFX_SSUB(_low, _min)) : \ + ((_value) >> EFX_SSUB(_min, _low)))) /* * Construct bit field portion @@ -1288,22 +1298,22 @@ extern int fix_lint; #define EFX_SHIFT64(_bit, _base) \ (((_bit) >= (_base) && (_bit) < (_base) + 64) ? \ - ((uint64_t)1 << ((_bit) - (_base))) : \ + ((uint64_t)1 << EFX_SSUB((_bit), (_base))) : \ 0U) #define EFX_SHIFT32(_bit, _base) \ (((_bit) >= (_base) && (_bit) < (_base) + 32) ? \ - ((uint32_t)1 << ((_bit) - (_base))) : \ + ((uint32_t)1 << EFX_SSUB((_bit),(_base))) : \ 0U) #define EFX_SHIFT16(_bit, _base) \ (((_bit) >= (_base) && (_bit) < (_base) + 16) ? \ - (uint16_t)(1 << ((_bit) - (_base))) : \ + (uint16_t)(1 << EFX_SSUB((_bit), (_base))) : \ 0U) #define EFX_SHIFT8(_bit, _base) \ (((_bit) >= (_base) && (_bit) < (_base) + 8) ? \ - (uint8_t)(1 << ((_bit) - (_base))) : \ + (uint8_t)(1 << EFX_SSUB((_bit), (_base))) : \ 0U) #define EFX_SET_OWORD_BIT64(_oword, _bit) \ |