X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=lib%2Fbitmap.c;h=a6939e18d7bb3bc4f8d0caba8004e6b075bd3983;hb=b3ea01668907bdb32b0c690d28f9f2b1298bd258;hp=26ebafa8c41d7e0ff602c0d2137a8ea284bb1ae5;hpb=5cb69bcacea70024252138a9cb4229a142a93389;p=linux-2.6-omap-h63xx.git

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 26ebafa8c41..a6939e18d7b 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -315,6 +315,22 @@ 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.
+ * @len: number of bits to be converted
+ */
+int bitmap_scnprintf_len(unsigned int len)
+{
+	/* we need 9 chars per word for 32 bit words (8 hexdigits + sep/null) */
+	int bitslen = ALIGN(len, CHUNKSZ);
+	int wordlen = CHUNKSZ / 4;
+	int buflen = (bitslen / wordlen) * (wordlen + 1) * sizeof(char);
+
+	return buflen;
+}
+EXPORT_SYMBOL(bitmap_scnprintf_len);
+
 /**
  * __bitmap_parse - convert an ASCII hex string into a bitmap.
  * @buf: pointer to buffer containing string.
@@ -469,6 +485,10 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen,
 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
 	int cur, rbot, rtop;
 
+	if (buflen == 0)
+		return 0;
+	buf[0] = 0;
+
 	rbot = cur = find_first_bit(maskp, nmaskbits);
 	while (cur < nmaskbits) {
 		rtop = cur;