From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/lib/find_bit.c | 87 ++++++++++++++++++-------------------------
1 files changed, 36 insertions(+), 51 deletions(-)
diff --git a/kernel/lib/find_bit.c b/kernel/lib/find_bit.c
index 8a54921..4a87510 100644
--- a/kernel/lib/find_bit.c
+++ b/kernel/lib/find_bit.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* bit search implementation
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
@@ -9,21 +10,17 @@
*
* Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
* size and improve performance, 2015.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
*/
#include <linux/bitops.h>
#include <linux/bitmap.h>
#include <linux/export.h>
#include <linux/kernel.h>
+#include <linux/minmax.h>
-#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
- !defined(find_next_and_bit)
-
+#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
+ !defined(find_next_bit_le) || !defined(find_next_zero_bit_le) || \
+ !defined(find_next_and_bit)
/*
* This is a common helper function for find_next_bit, find_next_zero_bit, and
* find_next_and_bit. The differences are:
@@ -31,11 +28,11 @@
* searching it for one bits.
* - The optional "addr2", which is anded with "addr1" if present.
*/
-static inline unsigned long _find_next_bit(const unsigned long *addr1,
+static unsigned long _find_next_bit(const unsigned long *addr1,
const unsigned long *addr2, unsigned long nbits,
- unsigned long start, unsigned long invert)
+ unsigned long start, unsigned long invert, unsigned long le)
{
- unsigned long tmp;
+ unsigned long tmp, mask;
if (unlikely(start >= nbits))
return nbits;
@@ -46,7 +43,12 @@
tmp ^= invert;
/* Handle 1st word. */
- tmp &= BITMAP_FIRST_WORD_MASK(start);
+ mask = BITMAP_FIRST_WORD_MASK(start);
+ if (le)
+ mask = swab(mask);
+
+ tmp &= mask;
+
start = round_down(start, BITS_PER_LONG);
while (!tmp) {
@@ -60,6 +62,9 @@
tmp ^= invert;
}
+ if (le)
+ tmp = swab(tmp);
+
return min(start + __ffs(tmp), nbits);
}
#endif
@@ -71,7 +76,7 @@
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, NULL, size, offset, 0UL);
+ return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
}
EXPORT_SYMBOL(find_next_bit);
#endif
@@ -80,7 +85,7 @@
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, NULL, size, offset, ~0UL);
+ return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
}
EXPORT_SYMBOL(find_next_zero_bit);
#endif
@@ -90,7 +95,7 @@
const unsigned long *addr2, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr1, addr2, size, offset, 0UL);
+ return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
}
EXPORT_SYMBOL(find_next_and_bit);
#endif
@@ -153,45 +158,11 @@
#ifdef __BIG_ENDIAN
-#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le)
-static inline unsigned long _find_next_bit_le(const unsigned long *addr1,
- const unsigned long *addr2, unsigned long nbits,
- unsigned long start, unsigned long invert)
-{
- unsigned long tmp;
-
- 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. */
- tmp &= swab(BITMAP_FIRST_WORD_MASK(start));
- 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;
- }
-
- return min(start + __ffs(swab(tmp)), nbits);
-}
-#endif
-
#ifndef find_next_zero_bit_le
unsigned long find_next_zero_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, NULL, size, offset, ~0UL);
+ return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
}
EXPORT_SYMBOL(find_next_zero_bit_le);
#endif
@@ -200,9 +171,23 @@
unsigned long find_next_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, NULL, size, offset, 0UL);
+ return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
}
EXPORT_SYMBOL(find_next_bit_le);
#endif
#endif /* __BIG_ENDIAN */
+
+unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
+ unsigned long size, unsigned long offset)
+{
+ offset = find_next_bit(addr, size, offset);
+ if (offset == size)
+ return size;
+
+ offset = round_down(offset, 8);
+ *clump = bitmap_get_value8(addr, offset);
+
+ return offset;
+}
+EXPORT_SYMBOL(find_next_clump8);
--
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