linux-kernel - [PATCH 08/29] tools: Add more bitmap functions

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Message-Id: <1479341856-30320-11-git-send-email-mawilcox@linuxonhyperv.com>
Date:   Wed, 16 Nov 2016 16:16:35 -0800
From:   Matthew Wilcox <mawilcox@...uxonhyperv.com>
To:     linux-kernel@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Konstantin Khlebnikov <koct9i@...il.com>,
        Ross Zwisler <ross.zwisler@...ux.intel.com>
Cc:     linux-fsdevel@...r.kernel.org,
        Matthew Wilcox <willy@...ux.intel.com>, linux-mm@...ck.org,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH 08/29] tools: Add more bitmap functions

From: Matthew Wilcox <willy@...ux.intel.com>

I need the following functions for the radix tree:

bitmap_fill
find_next_zero_bit
bitmap_empty
bitmap_full

Copy the implementations from include/linux/bitmap.h and lib/find_bit.c
---
 tools/include/linux/bitmap.h | 26 ++++++++++++++++++++++++++
 tools/lib/find_bit.c         |  8 ++++++++
 2 files changed, 34 insertions(+)

diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index 43c1c50..eef41d5 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -35,6 +35,32 @@ static inline void bitmap_zero(unsigned long *dst, int nbits)
 	}
 }
 
+static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
+{
+	unsigned int nlongs = BITS_TO_LONGS(nbits);
+	if (!small_const_nbits(nbits)) {
+		unsigned int len = (nlongs - 1) * sizeof(unsigned long);
+		memset(dst, 0xff,  len);
+	}
+	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
+}
+
+static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
+{
+	if (small_const_nbits(nbits))
+		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
+
+	return find_first_bit(src, nbits) == nbits;
+}
+
+static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
+{
+	if (small_const_nbits(nbits))
+		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
+
+	return find_first_zero_bit(src, nbits) == nbits;
+}
+
 static inline int bitmap_weight(const unsigned long *src, int nbits)
 {
 	if (small_const_nbits(nbits))
diff --git a/tools/lib/find_bit.c b/tools/lib/find_bit.c
index 9122a9e..de26b6f 100644
--- a/tools/lib/find_bit.c
+++ b/tools/lib/find_bit.c
@@ -66,6 +66,14 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
 }
 #endif
 
+#ifndef find_next_zero_bit
+unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
+				unsigned long offset)
+{
+	return _find_next_bit(addr, size, offset, ~0UL);
+}
+#endif
+
 #ifndef find_first_bit
 /*
  * Find the first set bit in a memory region.
-- 
2.10.2