linux-kernel - [PATCH 3/5] lib/bitmap: remove bitmap_ord_to

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Message-Id: <20220706182300.70862-4-yury.norov@gmail.com>
Date:   Wed,  6 Jul 2022 11:22:58 -0700
From:   Yury Norov <yury.norov@...il.com>
To:     linux-kernel@...r.kernel.org,
        Alexander Lobakin <alexandr.lobakin@...el.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Arnd Bergmann <arnd@...db.de>, David Gow <davidgow@...gle.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Isabella Basso <isabbasso@...eup.net>,
        Kees Cook <keescook@...omium.org>,
        Keith Busch <kbusch@...nel.org>,
        Kumar Kartikeya Dwivedi <memxor@...il.com>,
        Marco Elver <elver@...gle.com>,
        Mark Rutland <mark.rutland@....com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Steven Rostedt <rostedt@...dmis.org>,
        Toke Høiland-Jørgensen <toke@...hat.com>
Cc:     Yury Norov <yury.norov@...il.com>
Subject: [PATCH 3/5] lib/bitmap: remove bitmap_ord_to_pos

Now that we have find_nth_bit(), we can drop bitmap_ord_to_pos().

Signed-off-by: Yury Norov <yury.norov@...il.com>
---
 include/linux/bitmap.h |  1 -
 lib/bitmap.c           | 36 +++---------------------------------
 lib/nodemask.c         |  3 +--
 3 files changed, 4 insertions(+), 36 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index b2198665a064..91506057b240 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -222,7 +222,6 @@ void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int n
 #else
 #define bitmap_copy_le bitmap_copy
 #endif
-unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 int bitmap_print_to_pagebuf(bool list, char *buf,
 				   const unsigned long *maskp, int nmaskbits);
 
diff --git a/lib/bitmap.c b/lib/bitmap.c
index b580b381eca1..0b1082aa0b2c 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -956,36 +956,6 @@ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigne
 	return __bitmap_weight(buf, pos);
 }
 
-/**
- * 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)
- *	@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). 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 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 @nbits-1 are valid positions in @buf.
- */
-unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
-{
-	unsigned int pos;
-
-	for (pos = find_first_bit(buf, nbits);
-	     pos < nbits && ord;
-	     pos = find_next_bit(buf, nbits, pos + 1))
-		ord--;
-
-	return pos;
-}
-
 /**
  * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
  *	@dst: remapped result
@@ -1035,7 +1005,7 @@ void bitmap_remap(unsigned long *dst, const unsigned long *src,
 		if (n < 0 || w == 0)
 			set_bit(oldbit, dst);	/* identity map */
 		else
-			set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
+			set_bit(find_nth_bit(new, nbits, n % w + 1), dst);
 	}
 }
 EXPORT_SYMBOL(bitmap_remap);
@@ -1074,7 +1044,7 @@ int bitmap_bitremap(int oldbit, const unsigned long *old,
 	if (n < 0 || w == 0)
 		return oldbit;
 	else
-		return bitmap_ord_to_pos(new, n % w, bits);
+		return find_nth_bit(new, bits, n % w + 1);
 }
 EXPORT_SYMBOL(bitmap_bitremap);
 
@@ -1198,7 +1168,7 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 	 * The following code is a more efficient, but less
 	 * obvious, equivalent to the loop:
 	 *	for (m = 0; m < bitmap_weight(relmap, bits); m++) {
-	 *		n = bitmap_ord_to_pos(orig, m, bits);
+	 *		n = find_nth_bit(orig, bits, m + 1);
 	 *		if (test_bit(m, orig))
 	 *			set_bit(n, dst);
 	 *	}
diff --git a/lib/nodemask.c b/lib/nodemask.c
index e22647f5181b..7dad4ce8ff59 100644
--- a/lib/nodemask.c
+++ b/lib/nodemask.c
@@ -24,8 +24,7 @@ int node_random(const nodemask_t *maskp)
 
 	w = nodes_weight(*maskp);
 	if (w)
-		bit = bitmap_ord_to_pos(maskp->bits,
-			get_random_int() % w, MAX_NUMNODES);
+		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, get_random_int() % w + 1);
 	return bit;
 }
 #endif
-- 
2.34.1