| Message ID | 20231016165247.14212-10-aleksander.lobakin@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ip_tunnel: convert __be16 tunnel flags to bitmaps | expand |
On Mon, Oct 16, 2023 at 06:52:43PM +0200, Alexander Lobakin wrote: > Now that we have generic bitmap_read() and bitmap_write(), which are > inline and try to take care of non-bound-crossing and aligned cases > to keep them optimized, collapse bitmap_{get,set}_value8() into > simple wrappers around the former ones. > bloat-o-meter shows no difference in vmlinux and -2 bytes for > gpio-pca953x.ko, which says the code doesn't get optimized worse. That's just amazing! bloat-o-meter itself doesn't say on optimization, but in this case I think that BITS_PER_BYTE passed at compile time allows to generate just as good code with the generic bitmap_write/read(). Acked-by: Yury Norov <yury.norov@gmail.com> > Suggested-by: Yury Norov <yury.norov@gmail.com> > Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> > --- > include/linux/bitmap.h | 38 +++++--------------------------------- > 1 file changed, 5 insertions(+), 33 deletions(-) > > diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h > index 2020cb534ed7..c2680f67bc4e 100644 > --- a/include/linux/bitmap.h > +++ b/include/linux/bitmap.h > @@ -572,39 +572,6 @@ static inline void bitmap_from_u64(unsigned long *dst, u64 mask) > bitmap_from_arr64(dst, &mask, 64); > } > > -/** > - * bitmap_get_value8 - get an 8-bit value within a memory region > - * @map: address to the bitmap memory region > - * @start: bit offset of the 8-bit value; must be a multiple of 8 > - * > - * Returns the 8-bit value located at the @start bit offset within the @src > - * memory region. > - */ > -static inline unsigned long bitmap_get_value8(const unsigned long *map, > - unsigned long start) > -{ > - const size_t index = BIT_WORD(start); > - const unsigned long offset = start % BITS_PER_LONG; > - > - return (map[index] >> offset) & 0xFF; > -} > - > -/** > - * bitmap_set_value8 - set an 8-bit value within a memory region > - * @map: address to the bitmap memory region > - * @value: the 8-bit value; values wider than 8 bits may clobber bitmap > - * @start: bit offset of the 8-bit value; must be a multiple of 8 > - */ > -static inline void bitmap_set_value8(unsigned long *map, unsigned long value, > - unsigned long start) > -{ > - const size_t index = BIT_WORD(start); > - const unsigned long offset = start % BITS_PER_LONG; > - > - map[index] &= ~(0xFFUL << offset); > - map[index] |= value << offset; > -} > - > /** > * bitmap_read - read a value of n-bits from the memory region > * @map: address to the bitmap memory region > @@ -676,6 +643,11 @@ static inline void bitmap_write(unsigned long *map, > map[index + 1] |= (value >> space); > } > > +#define bitmap_get_value8(map, start) \ > + bitmap_read(map, start, BITS_PER_BYTE) > +#define bitmap_set_value8(map, value, start) \ > + bitmap_write(map, value, start, BITS_PER_BYTE) > + > #endif /* __ASSEMBLY__ */ > > #endif /* __LINUX_BITMAP_H */ > -- > 2.41.0
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 2020cb534ed7..c2680f67bc4e 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -572,39 +572,6 @@ static inline void bitmap_from_u64(unsigned long *dst, u64 mask) bitmap_from_arr64(dst, &mask, 64); } -/** - * bitmap_get_value8 - get an 8-bit value within a memory region - * @map: address to the bitmap memory region - * @start: bit offset of the 8-bit value; must be a multiple of 8 - * - * Returns the 8-bit value located at the @start bit offset within the @src - * memory region. - */ -static inline unsigned long bitmap_get_value8(const unsigned long *map, - unsigned long start) -{ - const size_t index = BIT_WORD(start); - const unsigned long offset = start % BITS_PER_LONG; - - return (map[index] >> offset) & 0xFF; -} - -/** - * bitmap_set_value8 - set an 8-bit value within a memory region - * @map: address to the bitmap memory region - * @value: the 8-bit value; values wider than 8 bits may clobber bitmap - * @start: bit offset of the 8-bit value; must be a multiple of 8 - */ -static inline void bitmap_set_value8(unsigned long *map, unsigned long value, - unsigned long start) -{ - const size_t index = BIT_WORD(start); - const unsigned long offset = start % BITS_PER_LONG; - - map[index] &= ~(0xFFUL << offset); - map[index] |= value << offset; -} - /** * bitmap_read - read a value of n-bits from the memory region * @map: address to the bitmap memory region @@ -676,6 +643,11 @@ static inline void bitmap_write(unsigned long *map, map[index + 1] |= (value >> space); } +#define bitmap_get_value8(map, start) \ + bitmap_read(map, start, BITS_PER_BYTE) +#define bitmap_set_value8(map, value, start) \ + bitmap_write(map, value, start, BITS_PER_BYTE) + #endif /* __ASSEMBLY__ */ #endif /* __LINUX_BITMAP_H */
Now that we have generic bitmap_read() and bitmap_write(), which are inline and try to take care of non-bound-crossing and aligned cases to keep them optimized, collapse bitmap_{get,set}_value8() into simple wrappers around the former ones. bloat-o-meter shows no difference in vmlinux and -2 bytes for gpio-pca953x.ko, which says the code doesn't get optimized worse. Suggested-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> --- include/linux/bitmap.h | 38 +++++--------------------------------- 1 file changed, 5 insertions(+), 33 deletions(-)