From ba1afa676d0babf99e99f5415db43fdd7ecef104 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 24 Jun 2022 17:31:47 +0800 Subject: lib: bitmap: fix the duplicated comments on bitmap_to_arr64() Thanks to the recent commit 0a97953fd221 ("lib: add bitmap_{from,to}_arr64") now we can directly convert a U64 value into a bitmap and vice verse. However when checking the header there is duplicated helper for bitmap_to_arr64(), but no bitmap_from_arr64(). Just fix the copy-n-paste error. Signed-off-by: Qu Wenruo Signed-off-by: Yury Norov --- include/linux/bitmap.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/bitmap.h') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 2e6cd5681040..f091a1664bf1 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -71,9 +71,9 @@ struct device; * bitmap_release_region(bitmap, pos, order) Free specified bit region * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst + * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst - * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst * bitmap_get_value8(map, start) Get 8bit value from map at start * bitmap_set_value8(map, value, start) Set 8bit value to map at start * -- cgit v1.2.3 From 3e7e5baaaba78075a7f3a57432609e363bf2a486 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Fri, 24 Jun 2022 14:13:12 +0200 Subject: bitmap: don't assume compiler evaluates small mem*() builtins calls Intel kernel bot triggered the build bug on ARC architecture that in fact is as follows: DECLARE_BITMAP(bitmap, BITS_PER_LONG); bitmap_clear(bitmap, 0, BITS_PER_LONG); BUILD_BUG_ON(!__builtin_constant_p(*bitmap)); which can be expanded to: unsigned long bitmap[1]; memset(bitmap, 0, sizeof(*bitmap)); BUILD_BUG_ON(!__builtin_constant_p(*bitmap)); In most cases, a compiler is able to expand small/simple mem*() calls to simple assignments or bitops, in this case that would mean: unsigned long bitmap[1] = { 0 }; BUILD_BUG_ON(!__builtin_constant_p(*bitmap)); and on most architectures this works, but not on ARC, despite having -O3 for every build. So, to make this work, in case when the last bit to modify is still within the first long (small_const_nbits()), just use plain assignments for the rest of bitmap_*() functions which still use mem*(), but didn't receive such compile-time optimizations yet. This doesn't have the same coverage as compilers provide, but at least something to start: text: add/remove: 3/7 grow/shrink: 43/78 up/down: 1848/-3370 (-1546) data: add/remove: 1/11 grow/shrink: 0/8 up/down: 4/-356 (-352) notably cpumask_*() family when NR_CPUS <= BITS_PER_LONG: netif_get_num_default_rss_queues 38 4 -34 cpumask_copy 90 - -90 cpumask_clear 146 - -146 and the abovementioned assertion started passing. Signed-off-by: Alexander Lobakin Signed-off-by: Yury Norov --- include/linux/bitmap.h | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'include/linux/bitmap.h') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index f091a1664bf1..c91638e507f2 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -238,20 +238,32 @@ extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) { unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); - memset(dst, 0, len); + + if (small_const_nbits(nbits)) + *dst = 0; + else + memset(dst, 0, len); } static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) { unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); - memset(dst, 0xff, len); + + if (small_const_nbits(nbits)) + *dst = ~0UL; + else + memset(dst, 0xff, len); } static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, unsigned int nbits) { unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); - memcpy(dst, src, len); + + if (small_const_nbits(nbits)) + *dst = *src; + else + memcpy(dst, src, len); } /* @@ -431,6 +443,8 @@ static __always_inline void bitmap_set(unsigned long *map, unsigned int start, { if (__builtin_constant_p(nbits) && nbits == 1) __set_bit(start, map); + else if (small_const_nbits(start + nbits)) + *map |= GENMASK(start + nbits - 1, start); else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && __builtin_constant_p(nbits & BITMAP_MEM_MASK) && @@ -445,6 +459,8 @@ static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, { if (__builtin_constant_p(nbits) && nbits == 1) __clear_bit(start, map); + else if (small_const_nbits(start + nbits)) + *map &= ~GENMASK(start + nbits - 1, start); else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && __builtin_constant_p(nbits & BITMAP_MEM_MASK) && -- cgit v1.2.3 From e2863a78593d638d3924a6f67900c4820034f349 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Fri, 1 Jul 2022 05:54:24 -0700 Subject: lib/bitmap: change return types to bool where appropriate Some bitmap functions return boolean results in int variables. Fix it by changing return types to bool. Signed-off-by: Yury Norov --- include/linux/bitmap.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/bitmap.h') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index c91638e507f2..e1a438bdda52 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -148,13 +148,13 @@ void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, unsigned int shift, unsigned int nbits); void bitmap_cut(unsigned long *dst, const unsigned long *src, unsigned int first, unsigned int cut, unsigned int nbits); -int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, +bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); -int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, +bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); void __bitmap_replace(unsigned long *dst, const unsigned long *old, const unsigned long *new, @@ -315,7 +315,7 @@ void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits); bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits)) #endif -static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, +static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1, const unsigned long *src2, unsigned int nbits) { if (small_const_nbits(nbits)) @@ -341,7 +341,7 @@ static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, __bitmap_xor(dst, src1, src2, nbits); } -static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, +static inline bool bitmap_andnot(unsigned long *dst, const unsigned long *src1, const unsigned long *src2, unsigned int nbits) { if (small_const_nbits(nbits)) -- cgit v1.2.3 From 4dea97f8636d0514befc9fc5cf342b351b7d0e20 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Fri, 1 Jul 2022 05:54:25 -0700 Subject: lib/bitmap: change type of bitmap_weight to unsigned long bitmap_weight() doesn't return negative values, so change it's type to unsigned long. It may help compiler to generate better code and catch bugs. Signed-off-by: Yury Norov --- include/linux/bitmap.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux/bitmap.h') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index e1a438bdda52..035d4ac66641 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -163,7 +163,7 @@ bool __bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); bool __bitmap_subset(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); -int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); +unsigned long __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); void __bitmap_set(unsigned long *map, unsigned int start, int len); void __bitmap_clear(unsigned long *map, unsigned int start, int len); @@ -431,7 +431,8 @@ static inline bool bitmap_full(const unsigned long *src, unsigned int nbits) return find_first_zero_bit(src, nbits) == nbits; } -static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) +static __always_inline +unsigned long bitmap_weight(const unsigned long *src, unsigned int nbits) { if (small_const_nbits(nbits)) return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); -- cgit v1.2.3