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Date: Wed, 14 Sep 2022 19:07:30 -0700
From: Yury Norov <yury.norov@...il.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>,
linux-kernel@...r.kernel.org
Cc: Yury Norov <yury.norov@...il.com>,
Alexey Klimov <klimov.linux@...il.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Andy Whitcroft <apw@...onical.com>,
Catalin Marinas <catalin.marinas@....com>,
David Laight <David.Laight@...LAB.COM>,
Dennis Zhou <dennis@...nel.org>,
Guenter Roeck <linux@...ck-us.net>,
Kees Cook <keescook@...omium.org>,
Rasmus Villemoes <linux@...musvillemoes.dk>,
Valentin Schneider <vschneid@...hat.com>,
Sven Schnelle <svens@...ux.ibm.com>,
Russell King <linux@...linux.org.uk>
Subject: [PATCH v4 4/4] 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 <yury.norov@...il.com>
---
tools/include/linux/find.h | 61 +++------------
tools/lib/find_bit.c | 149 +++++++++++++++++--------------------
2 files changed, 81 insertions(+), 129 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 <linux/bitops.h>
-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 <linux/bitmap.h>
#include <linux/kernel.h>
-#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
- !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:
- * - 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_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
*/
-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;
+#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; \
+})
- 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
+/*
+ * 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
+ */
+#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;
+ return FIND_FIRST_BIT(~addr[idx], /* nop */, size);
+}
+#endif
- for (idx = 0; idx * BITS_PER_LONG < size; idx++) {
- if (addr[idx] != ~0UL)
- return min(idx * BITS_PER_LONG + ffz(addr[idx]), size);
- }
+#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
- return size;
+#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
--
2.34.1
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