add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/lib/find_bit.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-or-later
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 /* bit search implementation
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  *
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  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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@@ -9,21 +10,17 @@
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  *
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  * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
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  * size and improve performance, 2015.
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- *
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- * This program is free software; you can redistribute it and/or
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- * modify it under the terms of the GNU General Public License
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- * as published by the Free Software Foundation; either version
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- * 2 of the License, or (at your option) any later version.
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  */
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 #include <linux/bitops.h>
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 #include <linux/bitmap.h>
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 #include <linux/export.h>
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 #include <linux/kernel.h>
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+#include <linux/minmax.h>
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20
 
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-#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
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-		!defined(find_next_and_bit)
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-
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+#if !defined(find_next_bit) || !defined(find_next_zero_bit) ||			\
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+	!defined(find_next_bit_le) || !defined(find_next_zero_bit_le) ||	\
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+	!defined(find_next_and_bit)
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 /*
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  * This is a common helper function for find_next_bit, find_next_zero_bit, and
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  * find_next_and_bit. The differences are:
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@@ -31,11 +28,11 @@
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  *    searching it for one bits.
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  *  - The optional "addr2", which is anded with "addr1" if present.
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  */
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-static inline unsigned long _find_next_bit(const unsigned long *addr1,
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+static unsigned long _find_next_bit(const unsigned long *addr1,
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 		const unsigned long *addr2, unsigned long nbits,
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-		unsigned long start, unsigned long invert)
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+		unsigned long start, unsigned long invert, unsigned long le)
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 {
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-	unsigned long tmp;
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+	unsigned long tmp, mask;
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 	if (unlikely(start >= nbits))
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 		return nbits;
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@@ -46,7 +43,12 @@
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 	tmp ^= invert;
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 	/* Handle 1st word. */
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-	tmp &= BITMAP_FIRST_WORD_MASK(start);
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+	mask = BITMAP_FIRST_WORD_MASK(start);
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+	if (le)
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+		mask = swab(mask);
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+
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+	tmp &= mask;
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+
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 	start = round_down(start, BITS_PER_LONG);
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 	while (!tmp) {
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@@ -60,6 +62,9 @@
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 		tmp ^= invert;
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 	}
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+	if (le)
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+		tmp = swab(tmp);
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+
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 	return min(start + __ffs(tmp), nbits);
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 }
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 #endif
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@@ -71,7 +76,7 @@
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 unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
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 			    unsigned long offset)
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 {
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-	return _find_next_bit(addr, NULL, size, offset, 0UL);
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+	return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
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 }
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 EXPORT_SYMBOL(find_next_bit);
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 #endif
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@@ -80,7 +85,7 @@
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 unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
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 				 unsigned long offset)
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 {
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-	return _find_next_bit(addr, NULL, size, offset, ~0UL);
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+	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
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 }
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 EXPORT_SYMBOL(find_next_zero_bit);
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 #endif
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@@ -90,7 +95,7 @@
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 		const unsigned long *addr2, unsigned long size,
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 		unsigned long offset)
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 {
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-	return _find_next_bit(addr1, addr2, size, offset, 0UL);
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+	return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
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 }
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 EXPORT_SYMBOL(find_next_and_bit);
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 #endif
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@@ -153,45 +158,11 @@
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 #ifdef __BIG_ENDIAN
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-#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le)
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-static inline unsigned long _find_next_bit_le(const unsigned long *addr1,
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-		const unsigned long *addr2, unsigned long nbits,
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-		unsigned long start, unsigned long invert)
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-{
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-	unsigned long tmp;
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-
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-	if (unlikely(start >= nbits))
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-		return nbits;
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-
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-	tmp = addr1[start / BITS_PER_LONG];
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-	if (addr2)
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-		tmp &= addr2[start / BITS_PER_LONG];
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-	tmp ^= invert;
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-
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-	/* Handle 1st word. */
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-	tmp &= swab(BITMAP_FIRST_WORD_MASK(start));
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-	start = round_down(start, BITS_PER_LONG);
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-
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-	while (!tmp) {
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-		start += BITS_PER_LONG;
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-		if (start >= nbits)
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-			return nbits;
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-
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-		tmp = addr1[start / BITS_PER_LONG];
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-		if (addr2)
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-			tmp &= addr2[start / BITS_PER_LONG];
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-		tmp ^= invert;
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-	}
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-
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-	return min(start + __ffs(swab(tmp)), nbits);
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-}
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-#endif
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-
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 #ifndef find_next_zero_bit_le
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 unsigned long find_next_zero_bit_le(const void *addr, unsigned
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 		long size, unsigned long offset)
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 {
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-	return _find_next_bit_le(addr, NULL, size, offset, ~0UL);
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+	return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
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 }
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 EXPORT_SYMBOL(find_next_zero_bit_le);
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 #endif
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@@ -200,9 +171,23 @@
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 unsigned long find_next_bit_le(const void *addr, unsigned
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 		long size, unsigned long offset)
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 {
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-	return _find_next_bit_le(addr, NULL, size, offset, 0UL);
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+	return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
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 }
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 EXPORT_SYMBOL(find_next_bit_le);
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 #endif
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 #endif /* __BIG_ENDIAN */
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+
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+unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
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+			       unsigned long size, unsigned long offset)
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+{
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+	offset = find_next_bit(addr, size, offset);
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+	if (offset == size)
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+		return size;
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+
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+	offset = round_down(offset, 8);
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+	*clump = bitmap_get_value8(addr, offset);
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+
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+	return offset;
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+}
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+EXPORT_SYMBOL(find_next_clump8);