[PATCH 0/8] lib: bitmap: Another small series

[PATCH 0/8] lib: bitmap: Another small series

[Rasmus Villemoes]

I found some patches in a long-forgotten branch - they still applied
cleanly, so I spiced them up with a few extra simplifications and
signed->unsigned conversions.

Rasmus Villemoes (8):
  lib: bitmap: More signed->unsigned conversions
  linux/nodemask.h: Update bitmap wrappers to take unsigned int
  linux/cpumask.h: Update bitmap wrappers to take unsigned int
  lib: bitmap: Update bitmap_onto to unsigned
  lib: bitmap: Change parameters of bitmap_fold to unsigned
  lib: bitmap: Simplify bitmap_pos_to_ord
  lib: bitmap: Simplify bitmap_ord_to_pos
  lib: bitmap: Minor changes of bitmap_remap

 include/linux/bitmap.h   | 22 ++++++-------
 include/linux/cpumask.h  | 22 ++++++-------
 include/linux/nodemask.h | 26 +++++++--------
 lib/bitmap.c             | 85 +++++++++++++++++++++---------------------------
 4 files changed, 72 insertions(+), 83 deletions(-)

-- 
2.1.3

[PATCH 1/8] lib: bitmap: More signed->unsigned conversions

[Rasmus Villemoes]

For consistency with the other bitmap_* functions, also make the nbits
parameter of bitmap_zero, bitmap_fill and bitmap_copy unsigned.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/bitmap.h | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e1c8d080c427..0106f02e5a93 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -156,33 +156,33 @@ extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
 #define small_const_nbits(nbits) \
 	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 
-static inline void bitmap_zero(unsigned long *dst, int nbits)
+static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		*dst = 0UL;
 	else {
-		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+		unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 		memset(dst, 0, len);
 	}
 }
 
-static inline void bitmap_fill(unsigned long *dst, int nbits)
+static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 {
-	size_t nlongs = BITS_TO_LONGS(nbits);
+	unsigned int nlongs = BITS_TO_LONGS(nbits);
 	if (!small_const_nbits(nbits)) {
-		int len = (nlongs - 1) * sizeof(unsigned long);
+		unsigned int len = (nlongs - 1) * sizeof(unsigned long);
 		memset(dst, 0xff,  len);
 	}
 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 }
 
 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
-			int nbits)
+			unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		*dst = *src;
 	else {
-		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+		unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 		memcpy(dst, src, len);
 	}
 }
-- 
2.1.3

[PATCH 2/8] linux/nodemask.h: Update bitmap wrappers to take unsigned int

[Rasmus Villemoes]

Since the various bitmap_* functions now take an unsigned int as nbits
parameter, it makes sense to also update the various wrappers.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/nodemask.h | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 83a6aeda899d..21cef483dc1b 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -120,13 +120,13 @@ static inline void __node_clear(int node, volatile nodemask_t *dstp)
 }
 
 #define nodes_setall(dst) __nodes_setall(&(dst), MAX_NUMNODES)
-static inline void __nodes_setall(nodemask_t *dstp, int nbits)
+static inline void __nodes_setall(nodemask_t *dstp, unsigned int nbits)
 {
 	bitmap_fill(dstp->bits, nbits);
 }
 
 #define nodes_clear(dst) __nodes_clear(&(dst), MAX_NUMNODES)
-static inline void __nodes_clear(nodemask_t *dstp, int nbits)
+static inline void __nodes_clear(nodemask_t *dstp, unsigned int nbits)
 {
 	bitmap_zero(dstp->bits, nbits);
 }
@@ -144,7 +144,7 @@ static inline int __node_test_and_set(int node, nodemask_t *addr)
 #define nodes_and(dst, src1, src2) \
 			__nodes_and(&(dst), &(src1), &(src2), MAX_NUMNODES)
 static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
@@ -152,7 +152,7 @@ static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
 #define nodes_or(dst, src1, src2) \
 			__nodes_or(&(dst), &(src1), &(src2), MAX_NUMNODES)
 static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
@@ -160,7 +160,7 @@ static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
 #define nodes_xor(dst, src1, src2) \
 			__nodes_xor(&(dst), &(src1), &(src2), MAX_NUMNODES)
 static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
@@ -168,7 +168,7 @@ static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
 #define nodes_andnot(dst, src1, src2) \
 			__nodes_andnot(&(dst), &(src1), &(src2), MAX_NUMNODES)
 static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
@@ -176,7 +176,7 @@ static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
 #define nodes_complement(dst, src) \
 			__nodes_complement(&(dst), &(src), MAX_NUMNODES)
 static inline void __nodes_complement(nodemask_t *dstp,
-					const nodemask_t *srcp, int nbits)
+					const nodemask_t *srcp, unsigned int nbits)
 {
 	bitmap_complement(dstp->bits, srcp->bits, nbits);
 }
@@ -184,7 +184,7 @@ static inline void __nodes_complement(nodemask_t *dstp,
 #define nodes_equal(src1, src2) \
 			__nodes_equal(&(src1), &(src2), MAX_NUMNODES)
 static inline int __nodes_equal(const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	return bitmap_equal(src1p->bits, src2p->bits, nbits);
 }
@@ -192,7 +192,7 @@ static inline int __nodes_equal(const nodemask_t *src1p,
 #define nodes_intersects(src1, src2) \
 			__nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
 static inline int __nodes_intersects(const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 }
@@ -200,25 +200,25 @@ static inline int __nodes_intersects(const nodemask_t *src1p,
 #define nodes_subset(src1, src2) \
 			__nodes_subset(&(src1), &(src2), MAX_NUMNODES)
 static inline int __nodes_subset(const nodemask_t *src1p,
-					const nodemask_t *src2p, int nbits)
+					const nodemask_t *src2p, unsigned int nbits)
 {
 	return bitmap_subset(src1p->bits, src2p->bits, nbits);
 }
 
 #define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
-static inline int __nodes_empty(const nodemask_t *srcp, int nbits)
+static inline int __nodes_empty(const nodemask_t *srcp, unsigned int nbits)
 {
 	return bitmap_empty(srcp->bits, nbits);
 }
 
 #define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
-static inline int __nodes_full(const nodemask_t *srcp, int nbits)
+static inline int __nodes_full(const nodemask_t *srcp, unsigned int nbits)
 {
 	return bitmap_full(srcp->bits, nbits);
 }
 
 #define nodes_weight(nodemask) __nodes_weight(&(nodemask), MAX_NUMNODES)
-static inline int __nodes_weight(const nodemask_t *srcp, int nbits)
+static inline int __nodes_weight(const nodemask_t *srcp, unsigned int nbits)
 {
 	return bitmap_weight(srcp->bits, nbits);
 }
-- 
2.1.3

[PATCH 3/8] linux/cpumask.h: Update bitmap wrappers to take unsigned int

[Rasmus Villemoes]

Since the various bitmap_* functions now take an unsigned int as nbits
parameter, it makes sense to also update the various wrappers, even
though they're marked as obsolete.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/cpumask.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 0a9a6da21e74..7fd6f4018b5a 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -888,13 +888,13 @@ static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 }
 
 #define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
-static inline void __cpus_setall(cpumask_t *dstp, int nbits)
+static inline void __cpus_setall(cpumask_t *dstp, unsigned int nbits)
 {
 	bitmap_fill(dstp->bits, nbits);
 }
 
 #define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
-static inline void __cpus_clear(cpumask_t *dstp, int nbits)
+static inline void __cpus_clear(cpumask_t *dstp, unsigned int nbits)
 {
 	bitmap_zero(dstp->bits, nbits);
 }
@@ -910,21 +910,21 @@ static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 
 #define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 static inline int __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	return bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
 
 #define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
 
 #define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
@@ -932,40 +932,40 @@ static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 #define cpus_andnot(dst, src1, src2) \
 				__cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 static inline int __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	return bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 }
 
 #define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 static inline int __cpus_equal(const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	return bitmap_equal(src1p->bits, src2p->bits, nbits);
 }
 
 #define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 static inline int __cpus_intersects(const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 }
 
 #define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 static inline int __cpus_subset(const cpumask_t *src1p,
-					const cpumask_t *src2p, int nbits)
+					const cpumask_t *src2p, unsigned int nbits)
 {
 	return bitmap_subset(src1p->bits, src2p->bits, nbits);
 }
 
 #define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
-static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
+static inline int __cpus_empty(const cpumask_t *srcp, unsigned int nbits)
 {
 	return bitmap_empty(srcp->bits, nbits);
 }
 
 #define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
-static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
+static inline int __cpus_weight(const cpumask_t *srcp, unsigned int nbits)
 {
 	return bitmap_weight(srcp->bits, nbits);
 }
-- 
2.1.3

[PATCH 4/8] lib: bitmap: Update bitmap_onto to unsigned

[Rasmus Villemoes]

Change the nbits parameter of bitmap_onto to unsigned int for
consistency with other bitmap_* functions.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/bitmap.h | 2 +-
 lib/bitmap.c           | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 0106f02e5a93..bf29a08bb3db 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -137,7 +137,7 @@ extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 extern int bitmap_bitremap(int oldbit,
 		const unsigned long *old, const unsigned long *new, int bits);
 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
-		const unsigned long *relmap, int bits);
+		const unsigned long *relmap, unsigned int bits);
 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 		int sz, int bits);
 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
diff --git a/lib/bitmap.c b/lib/bitmap.c
index b499ab6ada29..42d5886c3680 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -975,9 +975,9 @@ EXPORT_SYMBOL(bitmap_bitremap);
  * All bits in @dst not set by the above rule are cleared.
  */
 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
-			const unsigned long *relmap, int bits)
+			const unsigned long *relmap, unsigned int bits)
 {
-	int n, m;       	/* same meaning as in above comment */
+	unsigned int n, m;       	/* same meaning as in above comment */
 
 	if (dst == orig)	/* following doesn't handle inplace mappings */
 		return;
-- 
2.1.3

[PATCH 5/8] lib: bitmap: Change parameters of bitmap_fold to unsigned

[Rasmus Villemoes]

Change the sz and nbits parameters of bitmap_fold to unsigned int for
consistency with other bitmap_* functions, and to save another few
bytes in the generated code.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/bitmap.h | 2 +-
 lib/bitmap.c           | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index bf29a08bb3db..85e8fb091ed7 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -139,7 +139,7 @@ extern int bitmap_bitremap(int oldbit,
 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 		const unsigned long *relmap, unsigned int bits);
 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
-		int sz, int bits);
+		unsigned int sz, unsigned int nbits);
 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 42d5886c3680..1807d089eda7 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -1015,15 +1015,15 @@ EXPORT_SYMBOL(bitmap_onto);
  * Example [2] for bitmap_onto() for why and how to use this.
  */
 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
-			int sz, int bits)
+			unsigned int sz, unsigned int nbits)
 {
-	int oldbit;
+	unsigned int oldbit;
 
 	if (dst == orig)	/* following doesn't handle inplace mappings */
 		return;
-	bitmap_zero(dst, bits);
+	bitmap_zero(dst, nbits);
 
-	for_each_set_bit(oldbit, orig, bits)
+	for_each_set_bit(oldbit, orig, nbits)
 		set_bit(oldbit % sz, dst);
 }
 EXPORT_SYMBOL(bitmap_fold);
-- 
2.1.3

[PATCH 6/8] lib: bitmap: Simplify bitmap_pos_to_ord

[Rasmus Villemoes]

The ordinal of the a set bit is simply the number of set bits before
it; counting those doesn't need to be done one bit at a time. While at
it, update the parameters to unsigned int.

It is not completely unthinkable that gcc would see pos as
compile-time constant 0 in one of the uses of bitmap_pos_to_ord. Since
the static inline frontend bitmap_weight doesn't handle nbits==0
correctly (it would behave exactly as if nbits==BITS_PER_LONG), use
__bitmap_weight.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---

Notes:
    Alternatively, the last line could be spelled bitmap_weight(buf,
    pos+1)-1, but this is simpler.

 lib/bitmap.c | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 1807d089eda7..ab62a7e4d50f 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -713,10 +713,10 @@ EXPORT_SYMBOL(bitmap_parselist_user);
 /**
  * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
  *	@buf: pointer to a bitmap
- *	@pos: a bit position in @buf (0 <= @pos < @bits)
- *	@bits: number of valid bit positions in @buf
+ *	@pos: a bit position in @buf (0 <= @pos < @nbits)
+ *	@nbits: number of valid bit positions in @buf
  *
- * Map the bit at position @pos in @buf (of length @bits) to the
+ * Map the bit at position @pos in @buf (of length @nbits) to the
  * ordinal of which set bit it is.  If it is not set or if @pos
  * is not a valid bit position, map to -1.
  *
@@ -728,22 +728,12 @@ EXPORT_SYMBOL(bitmap_parselist_user);
  *
  * The bit positions 0 through @bits are valid positions in @buf.
  */
-static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
+static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
 {
-	int i, ord;
-
-	if (pos < 0 || pos >= bits || !test_bit(pos, buf))
+	if (pos >= nbits || !test_bit(pos, buf))
 		return -1;
 
-	i = find_first_bit(buf, bits);
-	ord = 0;
-	while (i < pos) {
-		i = find_next_bit(buf, bits, i + 1);
-	     	ord++;
-	}
-	BUG_ON(i != pos);
-
-	return ord;
+	return __bitmap_weight(buf, pos);
 }
 
 /**
-- 
2.1.3

[PATCH 7/8] lib: bitmap: Simplify bitmap_ord_to_pos

[Rasmus Villemoes]

Make the return value and the ord and nbits parameters of
bitmap_ord_to_pos unsigned.

Also, simplify the implementation and as a side effect make the result
fully defined, returning nbits for ord >= weight, in analogy with what
find_{first,next}_bit does. This is a better sentinel than the former
("unofficial") 0. No current users are affected by this change.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/bitmap.h |  2 +-
 lib/bitmap.c           | 28 +++++++++++-----------------
 2 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 85e8fb091ed7..e854934cdbf9 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -144,7 +144,7 @@ extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int
 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
-extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
+extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
 #define BITMAP_LAST_WORD_MASK(nbits)					\
diff --git a/lib/bitmap.c b/lib/bitmap.c
index ab62a7e4d50f..89b61e42f173 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -740,34 +740,28 @@ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigne
  * bitmap_ord_to_pos - find position of n-th set bit in bitmap
  *	@buf: pointer to bitmap
  *	@ord: ordinal bit position (n-th set bit, n >= 0)
- *	@bits: number of valid bit positions in @buf
+ *	@nbits: number of valid bit positions in @buf
  *
  * Map the ordinal offset of bit @ord in @buf to its position in @buf.
- * Value of @ord should be in range 0 <= @ord < weight(buf), else
- * results are undefined.
+ * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
+ * >= weight(buf), returns @nbits.
  *
  * If for example, just bits 4 through 7 are set in @buf, then @ord
  * values 0 through 3 will get mapped to 4 through 7, respectively,
- * and all other @ord values return undefined values.  When @ord value 3
+ * and all other @ord values returns @nbits.  When @ord value 3
  * gets mapped to (returns) @pos value 7 in this example, that means
  * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
  *
- * The bit positions 0 through @bits are valid positions in @buf.
+ * The bit positions 0 through @nbits-1 are valid positions in @buf.
  */
-int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
+unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
 {
-	int pos = 0;
+	unsigned int pos;
 
-	if (ord >= 0 && ord < bits) {
-		int i;
-
-		for (i = find_first_bit(buf, bits);
-		     i < bits && ord > 0;
-		     i = find_next_bit(buf, bits, i + 1))
-	     		ord--;
-		if (i < bits && ord == 0)
-			pos = i;
-	}
+	for (pos = find_first_bit(buf, nbits);
+	     pos < nbits && ord;
+	     pos = find_next_bit(buf, nbits, pos + 1))
+		ord--;
 
 	return pos;
 }
-- 
2.1.3

[PATCH 8/8] lib: bitmap: Minor changes of bitmap_remap

[Rasmus Villemoes]

Make the nbits parameter unsigned for consistency with most other
bitmap_* functions, and pull the test of empty dst out of the loop.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/bitmap.h |  2 +-
 lib/bitmap.c           | 23 ++++++++++++++---------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e854934cdbf9..690b180d723a 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -133,7 +133,7 @@ extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 			unsigned long *dst, int nbits);
 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
-		const unsigned long *old, const unsigned long *new, int bits);
+		const unsigned long *old, const unsigned long *new, unsigned int nbits);
 extern int bitmap_bitremap(int oldbit,
 		const unsigned long *old, const unsigned long *new, int bits);
 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 89b61e42f173..eda3bf0673ad 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -772,7 +772,7 @@ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsig
  *	@src: subset to be remapped
  *	@old: defines domain of map
  *	@new: defines range of map
- *	@bits: number of bits in each of these bitmaps
+ *	@nbits: number of bits in each of these bitmaps
  *
  * Let @old and @new define a mapping of bit positions, such that
  * whatever position is held by the n-th set bit in @old is mapped
@@ -800,22 +800,27 @@ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsig
  */
 void bitmap_remap(unsigned long *dst, const unsigned long *src,
 		const unsigned long *old, const unsigned long *new,
-		int bits)
+		unsigned int nbits)
 {
-	int oldbit, w;
+	unsigned int oldbit, w;
 
 	if (dst == src)		/* following doesn't handle inplace remaps */
 		return;
-	bitmap_zero(dst, bits);
 
-	w = bitmap_weight(new, bits);
-	for_each_set_bit(oldbit, src, bits) {
-	     	int n = bitmap_pos_to_ord(old, oldbit, bits);
+	w = bitmap_weight(new, nbits);
+	if (!w) {
+		bitmap_copy(dst, src, nbits);
+		return;
+	}
+
+	bitmap_zero(dst, nbits);
+	for_each_set_bit(oldbit, src, nbits) {
+		int n = bitmap_pos_to_ord(old, oldbit, nbits);
 
-		if (n < 0 || w == 0)
+		if (n < 0)
 			set_bit(oldbit, dst);	/* identity map */
 		else
-			set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
+			set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
 	}
 }
 EXPORT_SYMBOL(bitmap_remap);
-- 
2.1.3

[PATCH 8/8 v2] lib: bitmap: Make the bits parameter of bitmap_remap unsigned

[Rasmus Villemoes]

... and rename it to nbits, both for consistency with other bitmap_*
functions.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---

This is meant to replace 8/8 (lib: bitmap: Minor changes of
bitmap_remap), if you haven't gotten to that yet. No big deal either
way.

v2: Only do the signed->unsigned conversion. bitmap_remap only has a
single caller (via nodes_remap), so bloating it by special-casing
empty new isn't justified (and the commit log was wrong; it said
"empty dst").

 include/linux/bitmap.h |  2 +-
 lib/bitmap.c           | 16 ++++++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e854934cdbf9..690b180d723a 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -133,7 +133,7 @@ extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 			unsigned long *dst, int nbits);
 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
-		const unsigned long *old, const unsigned long *new, int bits);
+		const unsigned long *old, const unsigned long *new, unsigned int nbits);
 extern int bitmap_bitremap(int oldbit,
 		const unsigned long *old, const unsigned long *new, int bits);
 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 89b61e42f173..e864ab008f85 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -772,7 +772,7 @@ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsig
  *	@src: subset to be remapped
  *	@old: defines domain of map
  *	@new: defines range of map
- *	@bits: number of bits in each of these bitmaps
+ *	@nbits: number of bits in each of these bitmaps
  *
  * Let @old and @new define a mapping of bit positions, such that
  * whatever position is held by the n-th set bit in @old is mapped
@@ -800,22 +800,22 @@ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsig
  */
 void bitmap_remap(unsigned long *dst, const unsigned long *src,
 		const unsigned long *old, const unsigned long *new,
-		int bits)
+		unsigned int nbits)
 {
-	int oldbit, w;
+	unsigned int oldbit, w;
 
 	if (dst == src)		/* following doesn't handle inplace remaps */
 		return;
-	bitmap_zero(dst, bits);
+	bitmap_zero(dst, nbits);
 
-	w = bitmap_weight(new, bits);
-	for_each_set_bit(oldbit, src, bits) {
-	     	int n = bitmap_pos_to_ord(old, oldbit, bits);
+	w = bitmap_weight(new, nbits);
+	for_each_set_bit(oldbit, src, nbits) {
+		int n = bitmap_pos_to_ord(old, oldbit, nbits);
 
 		if (n < 0 || w == 0)
 			set_bit(oldbit, dst);	/* identity map */
 		else
-			set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
+			set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
 	}
 }
 EXPORT_SYMBOL(bitmap_remap);
-- 
2.1.3

[PATCH v3] lib: bitmap: Make the bits parameter of bitmap_remap unsigned

[Rasmus Villemoes]

Also, rename bits to nbits. Both changes for consistency with other
bitmap_* functions.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---

Notes:
    v3: Hopefully complete and unambiguous commit log.
    
    v2: Only do the signed->unsigned conversion. bitmap_remap only has a
    single caller (via nodes_remap), so bloating it by special-casing
    empty new isn't justified (and the commit log was wrong; it said
    "empty dst").

 include/linux/bitmap.h |  2 +-
 lib/bitmap.c           | 16 ++++++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e1c8d080c427..1a634b0e0cbe 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -133,7 +133,7 @@ extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 			unsigned long *dst, int nbits);
 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
-		const unsigned long *old, const unsigned long *new, int bits);
+		const unsigned long *old, const unsigned long *new, unsigned int nbits);
 extern int bitmap_bitremap(int oldbit,
 		const unsigned long *old, const unsigned long *new, int bits);
 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index b499ab6ada29..5884b974407b 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -788,7 +788,7 @@ int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
  *	@src: subset to be remapped
  *	@old: defines domain of map
  *	@new: defines range of map
- *	@bits: number of bits in each of these bitmaps
+ *	@nbits: number of bits in each of these bitmaps
  *
  * Let @old and @new define a mapping of bit positions, such that
  * whatever position is held by the n-th set bit in @old is mapped
@@ -816,22 +816,22 @@ int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
  */
 void bitmap_remap(unsigned long *dst, const unsigned long *src,
 		const unsigned long *old, const unsigned long *new,
-		int bits)
+		unsigned int nbits)
 {
-	int oldbit, w;
+	unsigned int oldbit, w;
 
 	if (dst == src)		/* following doesn't handle inplace remaps */
 		return;
-	bitmap_zero(dst, bits);
+	bitmap_zero(dst, nbits);
 
-	w = bitmap_weight(new, bits);
-	for_each_set_bit(oldbit, src, bits) {
-	     	int n = bitmap_pos_to_ord(old, oldbit, bits);
+	w = bitmap_weight(new, nbits);
+	for_each_set_bit(oldbit, src, nbits) {
+		int n = bitmap_pos_to_ord(old, oldbit, nbits);
 
 		if (n < 0 || w == 0)
 			set_bit(oldbit, dst);	/* identity map */
 		else
-			set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
+			set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
 	}
 }
 EXPORT_SYMBOL(bitmap_remap);
-- 
2.1.3