batman-adv: Replace bitarray operations with bitmap

bitarray.c consists mostly of functionality that is already available as part
of the standard kernel API. batman-adv could use architecture optimized code
and reduce the binary size by switching to the standard functions.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 9 insertions, 109 deletions

diff --git a/net/batman-adv/bitarray.c b/net/batman-adv/bitarray.c
index 6d0aa216b232..07ae6e1b8aca 100644
--- a/net/batman-adv/bitarray.c
+++ b/net/batman-adv/bitarray.c
@@ -24,100 +24,13 @@
 
 #include <linux/bitops.h>
 
-/* returns true if the corresponding bit in the given seq_bits indicates true
- * and curr_seqno is within range of last_seqno */
-int get_bit_status(const unsigned long *seq_bits, uint32_t last_seqno,
-		   uint32_t curr_seqno)
-{
-	int32_t diff, word_offset, word_num;
-
-	diff = last_seqno - curr_seqno;
-	if (diff < 0 || diff >= TQ_LOCAL_WINDOW_SIZE) {
-		return 0;
-	} else {
-		/* which word */
-		word_num = (last_seqno - curr_seqno) / WORD_BIT_SIZE;
-		/* which position in the selected word */
-		word_offset = (last_seqno - curr_seqno) % WORD_BIT_SIZE;
-
-		if (test_bit(word_offset, &seq_bits[word_num]))
-			return 1;
-		else
-			return 0;
-	}
-}
-
-/* turn corresponding bit on, so we can remember that we got the packet */
-void bit_mark(unsigned long *seq_bits, int32_t n)
-{
-	int32_t word_offset, word_num;
-
-	/* if too old, just drop it */
-	if (n < 0 || n >= TQ_LOCAL_WINDOW_SIZE)
-		return;
-
-	/* which word */
-	word_num = n / WORD_BIT_SIZE;
-	/* which position in the selected word */
-	word_offset = n % WORD_BIT_SIZE;
-
-	set_bit(word_offset, &seq_bits[word_num]); /* turn the position on */
-}
-
 /* shift the packet array by n places. */
-static void bit_shift(unsigned long *seq_bits, int32_t n)
+static void bat_bitmap_shift_left(unsigned long *seq_bits, int32_t n)
 {
-	int32_t word_offset, word_num;
-	int32_t i;
-
 	if (n <= 0 || n >= TQ_LOCAL_WINDOW_SIZE)
 		return;
 
-	word_offset = n % WORD_BIT_SIZE;/* shift how much inside each word */
-	word_num = n / WORD_BIT_SIZE;	/* shift over how much (full) words */
-
-	for (i = NUM_WORDS - 1; i > word_num; i--) {
-		/* going from old to new, so we don't overwrite the data we copy
-		 * from.
-		 *
-		 * left is high, right is low: FEDC BA98 7654 3210
-		 *					  ^^ ^^
-		 *			       vvvv
-		 * ^^^^ = from, vvvvv =to, we'd have word_num==1 and
-		 * word_offset==WORD_BIT_SIZE/2 ????? in this example.
-		 * (=24 bits)
-		 *
-		 * our desired output would be: 9876 5432 1000 0000
-		 * */
-
-		seq_bits[i] =
-			(seq_bits[i - word_num] << word_offset) +
-			/* take the lower port from the left half, shift it left
-			 * to its final position */
-			(seq_bits[i - word_num - 1] >>
-			 (WORD_BIT_SIZE-word_offset));
-		/* and the upper part of the right half and shift it left to
-		 * its position */
-		/* for our example that would be: word[0] = 9800 + 0076 =
-		 * 9876 */
-	}
-	/* now for our last word, i==word_num, we only have its "left" half.
-	 * that's the 1000 word in our example.*/
-
-	seq_bits[i] = (seq_bits[i - word_num] << word_offset);
-
-	/* pad the rest with 0, if there is anything */
-	i--;
-
-	for (; i >= 0; i--)
-		seq_bits[i] = 0;
-}
-
-static void bit_reset_window(unsigned long *seq_bits)
-{
-	int i;
-	for (i = 0; i < NUM_WORDS; i++)
-		seq_bits[i] = 0;
+	bitmap_shift_left(seq_bits, seq_bits, n, TQ_LOCAL_WINDOW_SIZE);
 }
 
 
@@ -137,7 +50,7 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
 
 	if ((seq_num_diff <= 0) && (seq_num_diff > -TQ_LOCAL_WINDOW_SIZE)) {
 		if (set_mark)
-			bit_mark(seq_bits, -seq_num_diff);
+			bat_set_bit(seq_bits, -seq_num_diff);
 		return 0;
 	}
 
@@ -145,10 +58,10 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
 	 * set the mark if required */
 
 	if ((seq_num_diff > 0) && (seq_num_diff < TQ_LOCAL_WINDOW_SIZE)) {
-		bit_shift(seq_bits, seq_num_diff);
+		bat_bitmap_shift_left(seq_bits, seq_num_diff);
 
 		if (set_mark)
-			bit_mark(seq_bits, 0);
+			bat_set_bit(seq_bits, 0);
 		return 1;
 	}
 
@@ -159,9 +72,9 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
 		bat_dbg(DBG_BATMAN, bat_priv,
 			"We missed a lot of packets (%i) !\n",
 			seq_num_diff - 1);
-		bit_reset_window(seq_bits);
+		bitmap_zero(seq_bits, TQ_LOCAL_WINDOW_SIZE);
 		if (set_mark)
-			bit_mark(seq_bits, 0);
+			bat_set_bit(seq_bits, 0);
 		return 1;
 	}
 
@@ -176,9 +89,9 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
 		bat_dbg(DBG_BATMAN, bat_priv,
 			"Other host probably restarted!\n");
 
-		bit_reset_window(seq_bits);
+		bitmap_zero(seq_bits, TQ_LOCAL_WINDOW_SIZE);
 		if (set_mark)
-			bit_mark(seq_bits, 0);
+			bat_set_bit(seq_bits, 0);
 
 		return 1;
 	}
@@ -186,16 +99,3 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
 	/* never reached */
 	return 0;
 }
-
-/* count the hamming weight, how many good packets did we receive? just count
- * the 1's.
- */
-int bit_packet_count(const unsigned long *seq_bits)
-{
-	int i, hamming = 0;
-
-	for (i = 0; i < NUM_WORDS; i++)
-		hamming += hweight_long(seq_bits[i]);
-
-	return hamming;
-}