From 6333cb31a711cc709b6a960d082e04546f4459ee Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Wed, 14 Sep 2022 19:07:30 -0700 Subject: [PATCH] tools: sync find_bit() implementation Sync find_first_bit() and find_next_bit() implementation with the mother kernel. Also, drop unused find_last_bit() and find_next_clump8(). Signed-off-by: Yury Norov --- tools/include/linux/find.h | 61 +++------------ tools/lib/find_bit.c | 153 +++++++++++++++++-------------------- 2 files changed, 83 insertions(+), 131 deletions(-) diff --git a/tools/include/linux/find.h b/tools/include/linux/find.h index 47e2bd6c5174..38c0a542b0e2 100644 --- a/tools/include/linux/find.h +++ b/tools/include/linux/find.h @@ -8,21 +8,23 @@ #include -extern unsigned long _find_next_bit(const unsigned long *addr1, - const unsigned long *addr2, unsigned long nbits, - unsigned long start, unsigned long invert, unsigned long le); +unsigned long _find_next_bit(const unsigned long *addr1, unsigned long nbits, + unsigned long start); +unsigned long _find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2, + unsigned long nbits, unsigned long start); +unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits, + unsigned long start); extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size); extern unsigned long _find_first_and_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long size); extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size); -extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size); #ifndef find_next_bit /** * find_next_bit - find the next set bit in a memory region * @addr: The address to base the search on - * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * @offset: The bitnumber to start searching at * * Returns the bit number for the next set bit * If no bits are set, returns @size. @@ -41,7 +43,7 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size, return val ? __ffs(val) : size; } - return _find_next_bit(addr, NULL, size, offset, 0UL, 0); + return _find_next_bit(addr, size, offset); } #endif @@ -50,8 +52,8 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size, * find_next_and_bit - find the next set bit in both memory regions * @addr1: The first address to base the search on * @addr2: The second address to base the search on - * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * @offset: The bitnumber to start searching at * * Returns the bit number for the next set bit * If no bits are set, returns @size. @@ -71,7 +73,7 @@ unsigned long find_next_and_bit(const unsigned long *addr1, return val ? __ffs(val) : size; } - return _find_next_bit(addr1, addr2, size, offset, 0UL, 0); + return _find_next_and_bit(addr1, addr2, size, offset); } #endif @@ -79,8 +81,8 @@ unsigned long find_next_and_bit(const unsigned long *addr1, /** * find_next_zero_bit - find the next cleared bit in a memory region * @addr: The address to base the search on - * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * @offset: The bitnumber to start searching at * * Returns the bit number of the next zero bit * If no bits are zero, returns @size. @@ -99,7 +101,7 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, return val == ~0UL ? size : ffz(val); } - return _find_next_bit(addr, NULL, size, offset, ~0UL, 0); + return _find_next_zero_bit(addr, size, offset); } #endif @@ -172,43 +174,4 @@ unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) } #endif -#ifndef find_last_bit -/** - * find_last_bit - find the last set bit in a memory region - * @addr: The address to start the search at - * @size: The number of bits to search - * - * Returns the bit number of the last set bit, or size. - */ -static inline -unsigned long find_last_bit(const unsigned long *addr, unsigned long size) -{ - if (small_const_nbits(size)) { - unsigned long val = *addr & GENMASK(size - 1, 0); - - return val ? __fls(val) : size; - } - - return _find_last_bit(addr, size); -} -#endif - -/** - * find_next_clump8 - find next 8-bit clump with set bits in a memory region - * @clump: location to store copy of found clump - * @addr: address to base the search on - * @size: bitmap size in number of bits - * @offset: bit offset at which to start searching - * - * Returns the bit offset for the next set clump; the found clump value is - * copied to the location pointed by @clump. If no bits are set, returns @size. - */ -extern unsigned long find_next_clump8(unsigned long *clump, - const unsigned long *addr, - unsigned long size, unsigned long offset); - -#define find_first_clump8(clump, bits, size) \ - find_next_clump8((clump), (bits), (size), 0) - - #endif /*__LINUX_FIND_H_ */ diff --git a/tools/lib/find_bit.c b/tools/lib/find_bit.c index ba4b8d94e004..6a3dc167d30e 100644 --- a/tools/lib/find_bit.c +++ b/tools/lib/find_bit.c @@ -18,66 +18,54 @@ #include #include -#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \ - !defined(find_next_and_bit) +/* + * Common helper for find_bit() function family + * @FETCH: The expression that fetches and pre-processes each word of bitmap(s) + * @MUNGE: The expression that post-processes a word containing found bit (may be empty) + * @size: The bitmap size in bits + */ +#define FIND_FIRST_BIT(FETCH, MUNGE, size) \ +({ \ + unsigned long idx, val, sz = (size); \ + \ + for (idx = 0; idx * BITS_PER_LONG < sz; idx++) { \ + val = (FETCH); \ + if (val) { \ + sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(val)), sz); \ + break; \ + } \ + } \ + \ + sz; \ +}) /* - * This is a common helper function for find_next_bit, find_next_zero_bit, and - * find_next_and_bit. The differences are: - * - The "invert" argument, which is XORed with each fetched word before - * searching it for one bits. - * - The optional "addr2", which is anded with "addr1" if present. + * Common helper for find_next_bit() function family + * @FETCH: The expression that fetches and pre-processes each word of bitmap(s) + * @MUNGE: The expression that post-processes a word containing found bit (may be empty) + * @size: The bitmap size in bits + * @start: The bitnumber to start searching at */ -unsigned long _find_next_bit(const unsigned long *addr1, - const unsigned long *addr2, unsigned long nbits, - unsigned long start, unsigned long invert, unsigned long le) -{ - unsigned long tmp, mask; - (void) le; - - if (unlikely(start >= nbits)) - return nbits; - - tmp = addr1[start / BITS_PER_LONG]; - if (addr2) - tmp &= addr2[start / BITS_PER_LONG]; - tmp ^= invert; - - /* Handle 1st word. */ - mask = BITMAP_FIRST_WORD_MASK(start); - - /* - * Due to the lack of swab() in tools, and the fact that it doesn't - * need little-endian support, just comment it out - */ -#if (0) - if (le) - mask = swab(mask); -#endif - - tmp &= mask; - - start = round_down(start, BITS_PER_LONG); - - while (!tmp) { - start += BITS_PER_LONG; - if (start >= nbits) - return nbits; - - tmp = addr1[start / BITS_PER_LONG]; - if (addr2) - tmp &= addr2[start / BITS_PER_LONG]; - tmp ^= invert; - } - -#if (0) - if (le) - tmp = swab(tmp); -#endif - - return min(start + __ffs(tmp), nbits); -} -#endif +#define FIND_NEXT_BIT(FETCH, MUNGE, size, start) \ +({ \ + unsigned long mask, idx, tmp, sz = (size), __start = (start); \ + \ + if (unlikely(__start >= sz)) \ + goto out; \ + \ + mask = MUNGE(BITMAP_FIRST_WORD_MASK(__start)); \ + idx = __start / BITS_PER_LONG; \ + \ + for (tmp = (FETCH) & mask; !tmp; tmp = (FETCH)) { \ + if ((idx + 1) * BITS_PER_LONG >= sz) \ + goto out; \ + idx++; \ + } \ + \ + sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(tmp)), sz); \ +out: \ + sz; \ +}) #ifndef find_first_bit /* @@ -85,14 +73,7 @@ unsigned long _find_next_bit(const unsigned long *addr1, */ unsigned long _find_first_bit(const unsigned long *addr, unsigned long size) { - unsigned long idx; - - for (idx = 0; idx * BITS_PER_LONG < size; idx++) { - if (addr[idx]) - return min(idx * BITS_PER_LONG + __ffs(addr[idx]), size); - } - - return size; + return FIND_FIRST_BIT(addr[idx], /* nop */, size); } #endif @@ -104,15 +85,7 @@ unsigned long _find_first_and_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long size) { - unsigned long idx, val; - - for (idx = 0; idx * BITS_PER_LONG < size; idx++) { - val = addr1[idx] & addr2[idx]; - if (val) - return min(idx * BITS_PER_LONG + __ffs(val), size); - } - - return size; + return FIND_FIRST_BIT(addr1[idx] & addr2[idx], /* nop */, size); } #endif @@ -122,13 +95,29 @@ unsigned long _find_first_and_bit(const unsigned long *addr1, */ unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size) { - unsigned long idx; - - for (idx = 0; idx * BITS_PER_LONG < size; idx++) { - if (addr[idx] != ~0UL) - return min(idx * BITS_PER_LONG + ffz(addr[idx]), size); - } - - return size; + return FIND_FIRST_BIT(~addr[idx], /* nop */, size); +} +#endif + +#ifndef find_next_bit +unsigned long _find_next_bit(const unsigned long *addr, unsigned long nbits, unsigned long start) +{ + return FIND_NEXT_BIT(addr[idx], /* nop */, nbits, start); +} +#endif + +#ifndef find_next_and_bit +unsigned long _find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2, + unsigned long nbits, unsigned long start) +{ + return FIND_NEXT_BIT(addr1[idx] & addr2[idx], /* nop */, nbits, start); +} +#endif + +#ifndef find_next_zero_bit +unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits, + unsigned long start) +{ + return FIND_NEXT_BIT(~addr[idx], /* nop */, nbits, start); } #endif