X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=lib%2Fbitmap.c;h=11bf49750583af6087e5a65674a4c74247071ea5;hb=122ca0076e5f84fa12943f22f6586ff285670783;hp=c2006bfeea417e72f838ad840c5f8eff32421358;hpb=ccbe329bcd87924baed96474ec0a6725e3957897;p=safe%2Fjmp%2Flinux-2.6

diff --git a/lib/bitmap.c b/lib/bitmap.c
index c2006bf..11bf497 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -179,14 +179,16 @@ void __bitmap_shift_left(unsigned long *dst,
 }
 EXPORT_SYMBOL(__bitmap_shift_left);
 
-void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
+int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 				const unsigned long *bitmap2, int bits)
 {
 	int k;
 	int nr = BITS_TO_LONGS(bits);
+	unsigned long result = 0;
 
 	for (k = 0; k < nr; k++)
-		dst[k] = bitmap1[k] & bitmap2[k];
+		result |= (dst[k] = bitmap1[k] & bitmap2[k]);
+	return result != 0;
 }
 EXPORT_SYMBOL(__bitmap_and);
 
@@ -212,14 +214,16 @@ void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 }
 EXPORT_SYMBOL(__bitmap_xor);
 
-void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
+int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 				const unsigned long *bitmap2, int bits)
 {
 	int k;
 	int nr = BITS_TO_LONGS(bits);
+	unsigned long result = 0;
 
 	for (k = 0; k < nr; k++)
-		dst[k] = bitmap1[k] & ~bitmap2[k];
+		result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
+	return result != 0;
 }
 EXPORT_SYMBOL(__bitmap_andnot);
 
@@ -267,6 +271,87 @@ int __bitmap_weight(const unsigned long *bitmap, int bits)
 }
 EXPORT_SYMBOL(__bitmap_weight);
 
+#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
+
+void bitmap_set(unsigned long *map, int start, int nr)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const int size = start + nr;
+	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+
+	while (nr - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		nr -= bits_to_set;
+		bits_to_set = BITS_PER_LONG;
+		mask_to_set = ~0UL;
+		p++;
+	}
+	if (nr) {
+		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+		*p |= mask_to_set;
+	}
+}
+EXPORT_SYMBOL(bitmap_set);
+
+void bitmap_clear(unsigned long *map, int start, int nr)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const int size = start + nr;
+	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+
+	while (nr - bits_to_clear >= 0) {
+		*p &= ~mask_to_clear;
+		nr -= bits_to_clear;
+		bits_to_clear = BITS_PER_LONG;
+		mask_to_clear = ~0UL;
+		p++;
+	}
+	if (nr) {
+		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+		*p &= ~mask_to_clear;
+	}
+}
+EXPORT_SYMBOL(bitmap_clear);
+
+/*
+ * bitmap_find_next_zero_area - find a contiguous aligned zero area
+ * @map: The address to base the search on
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @align_mask: Alignment mask for zero area
+ *
+ * The @align_mask should be one less than a power of 2; the effect is that
+ * the bit offset of all zero areas this function finds is multiples of that
+ * power of 2. A @align_mask of 0 means no alignment is required.
+ */
+unsigned long bitmap_find_next_zero_area(unsigned long *map,
+					 unsigned long size,
+					 unsigned long start,
+					 unsigned int nr,
+					 unsigned long align_mask)
+{
+	unsigned long index, end, i;
+again:
+	index = find_next_zero_bit(map, size, start);
+
+	/* Align allocation */
+	index = __ALIGN_MASK(index, align_mask);
+
+	end = index + nr;
+	if (end > size)
+		return end;
+	i = find_next_bit(map, end, index);
+	if (i < end) {
+		start = i + 1;
+		goto again;
+	}
+	return index;
+}
+EXPORT_SYMBOL(bitmap_find_next_zero_area);
+
 /*
  * Bitmap printing & parsing functions: first version by Bill Irwin,
  * second version by Paul Jackson, third by Joe Korty.
@@ -316,17 +401,6 @@ int bitmap_scnprintf(char *buf, unsigned int buflen,
 EXPORT_SYMBOL(bitmap_scnprintf);
 
 /**
- * bitmap_scnprintf_len - return buffer length needed to convert
- * bitmap to an ASCII hex string
- * @nr_bits: number of bits to be converted
- */
-int bitmap_scnprintf_len(unsigned int nr_bits)
-{
-	unsigned int nr_nibbles = ALIGN(nr_bits, 4) / 4;
-	return nr_nibbles + ALIGN(nr_nibbles, CHUNKSZ / 4) / (CHUNKSZ / 4) - 1;
-}
-
-/**
  * __bitmap_parse - convert an ASCII hex string into a bitmap.
  * @buf: pointer to buffer containing string.
  * @buflen: buffer size in bytes.  If string is smaller than this
@@ -959,15 +1033,15 @@ done:
  */
 int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
 {
-	int pos;		/* scans bitmap by regions of size order */
+	int pos, end;		/* scans bitmap by regions of size order */
 
-	for (pos = 0; pos < bits; pos += (1 << order))
-		if (__reg_op(bitmap, pos, order, REG_OP_ISFREE))
-			break;
-	if (pos == bits)
-		return -ENOMEM;
-	__reg_op(bitmap, pos, order, REG_OP_ALLOC);
-	return pos;
+	for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
+		if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
+			continue;
+		__reg_op(bitmap, pos, order, REG_OP_ALLOC);
+		return pos;
+	}
+	return -ENOMEM;
 }
 EXPORT_SYMBOL(bitmap_find_free_region);