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Commit 0079d2ce authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Antonio Quartulli
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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: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarAntonio Quartulli <ordex@autistici.org>
parent c1faead3
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+8 −7
Original line number Original line Diff line number Diff line
@@ -850,7 +850,7 @@ static int bat_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
	hlist_for_each_entry_rcu(tmp_neigh_node, node,
	hlist_for_each_entry_rcu(tmp_neigh_node, node,
				 &orig_node->neigh_list, list) {
				 &orig_node->neigh_list, list) {


		is_duplicate |= get_bit_status(tmp_neigh_node->real_bits,
		is_duplicate |= bat_test_bit(tmp_neigh_node->real_bits,
					     orig_node->last_real_seqno,
					     orig_node->last_real_seqno,
					     batman_ogm_packet->seqno);
					     batman_ogm_packet->seqno);


@@ -866,7 +866,8 @@ static int bat_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
					      seq_diff, set_mark);
					      seq_diff, set_mark);


		tmp_neigh_node->real_packet_count =
		tmp_neigh_node->real_packet_count =
			bit_packet_count(tmp_neigh_node->real_bits);
			bitmap_weight(tmp_neigh_node->real_bits,
				      TQ_LOCAL_WINDOW_SIZE);
	}
	}
	rcu_read_unlock();
	rcu_read_unlock();


@@ -998,11 +999,11 @@ static void bat_iv_ogm_process(const struct ethhdr *ethhdr,


			spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
			spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
			word = &(orig_neigh_node->bcast_own[offset]);
			word = &(orig_neigh_node->bcast_own[offset]);
			bit_mark(word,
			bat_set_bit(word,
				    if_incoming_seqno -
				    if_incoming_seqno -
						batman_ogm_packet->seqno - 2);
						batman_ogm_packet->seqno - 2);
			orig_neigh_node->bcast_own_sum[if_incoming->if_num] =
			orig_neigh_node->bcast_own_sum[if_incoming->if_num] =
				bit_packet_count(word);
				bitmap_weight(word, TQ_LOCAL_WINDOW_SIZE);
			spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
			spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
		}
		}


+9 −109
Original line number Original line Diff line number Diff line
@@ -24,100 +24,13 @@


#include <linux/bitops.h>
#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. */
/* 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)
	if (n <= 0 || n >= TQ_LOCAL_WINDOW_SIZE)
		return;
		return;


	word_offset = n % WORD_BIT_SIZE;/* shift how much inside each word */
	bitmap_shift_left(seq_bits, seq_bits, n, TQ_LOCAL_WINDOW_SIZE);
	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;
}
}




@@ -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 ((seq_num_diff <= 0) && (seq_num_diff > -TQ_LOCAL_WINDOW_SIZE)) {
		if (set_mark)
		if (set_mark)
			bit_mark(seq_bits, -seq_num_diff);
			bat_set_bit(seq_bits, -seq_num_diff);
		return 0;
		return 0;
	}
	}


@@ -145,10 +58,10 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
	 * set the mark if required */
	 * set the mark if required */


	if ((seq_num_diff > 0) && (seq_num_diff < TQ_LOCAL_WINDOW_SIZE)) {
	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)
		if (set_mark)
			bit_mark(seq_bits, 0);
			bat_set_bit(seq_bits, 0);
		return 1;
		return 1;
	}
	}


@@ -159,9 +72,9 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
		bat_dbg(DBG_BATMAN, bat_priv,
		bat_dbg(DBG_BATMAN, bat_priv,
			"We missed a lot of packets (%i) !\n",
			"We missed a lot of packets (%i) !\n",
			seq_num_diff - 1);
			seq_num_diff - 1);
		bit_reset_window(seq_bits);
		bitmap_zero(seq_bits, TQ_LOCAL_WINDOW_SIZE);
		if (set_mark)
		if (set_mark)
			bit_mark(seq_bits, 0);
			bat_set_bit(seq_bits, 0);
		return 1;
		return 1;
	}
	}


@@ -176,9 +89,9 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
		bat_dbg(DBG_BATMAN, bat_priv,
		bat_dbg(DBG_BATMAN, bat_priv,
			"Other host probably restarted!\n");
			"Other host probably restarted!\n");


		bit_reset_window(seq_bits);
		bitmap_zero(seq_bits, TQ_LOCAL_WINDOW_SIZE);
		if (set_mark)
		if (set_mark)
			bit_mark(seq_bits, 0);
			bat_set_bit(seq_bits, 0);


		return 1;
		return 1;
	}
	}
@@ -186,16 +99,3 @@ int bit_get_packet(void *priv, unsigned long *seq_bits,
	/* never reached */
	/* never reached */
	return 0;
	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;
}
+18 −8
Original line number Original line Diff line number Diff line
@@ -22,23 +22,33 @@
#ifndef _NET_BATMAN_ADV_BITARRAY_H_
#ifndef _NET_BATMAN_ADV_BITARRAY_H_
#define _NET_BATMAN_ADV_BITARRAY_H_
#define _NET_BATMAN_ADV_BITARRAY_H_


#define WORD_BIT_SIZE (sizeof(unsigned long) * 8)

/* returns true if the corresponding bit in the given seq_bits indicates true
/* returns true if the corresponding bit in the given seq_bits indicates true
 * and curr_seqno is within range of last_seqno */
 * and curr_seqno is within range of last_seqno */
int get_bit_status(const unsigned long *seq_bits, uint32_t last_seqno,
static inline int bat_test_bit(const unsigned long *seq_bits,
		   uint32_t curr_seqno);
			       uint32_t last_seqno, uint32_t curr_seqno)
{
	int32_t diff;

	diff = last_seqno - curr_seqno;
	if (diff < 0 || diff >= TQ_LOCAL_WINDOW_SIZE)
		return 0;
	else
		return  test_bit(diff, seq_bits);
}


/* turn corresponding bit on, so we can remember that we got the packet */
/* turn corresponding bit on, so we can remember that we got the packet */
void bit_mark(unsigned long *seq_bits, int32_t n);
static inline void bat_set_bit(unsigned long *seq_bits, int32_t n)
{
	/* if too old, just drop it */
	if (n < 0 || n >= TQ_LOCAL_WINDOW_SIZE)
		return;


	set_bit(n, seq_bits); /* turn the position on */
}


/* receive and process one packet, returns 1 if received seq_num is considered
/* receive and process one packet, returns 1 if received seq_num is considered
 * new, 0 if old  */
 * new, 0 if old  */
int bit_get_packet(void *priv, unsigned long *seq_bits,
int bit_get_packet(void *priv, unsigned long *seq_bits,
		   int32_t seq_num_diff, int set_mark);
		   int32_t seq_num_diff, int set_mark);


/* count the hamming weight, how many good packets did we receive? */
int bit_packet_count(const unsigned long *seq_bits);

#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
+1 −1
Original line number Original line Diff line number Diff line
@@ -65,7 +65,7 @@


#define NULL_IFINDEX 0 /* dummy ifindex used to avoid iface checks */
#define NULL_IFINDEX 0 /* dummy ifindex used to avoid iface checks */


#define NUM_WORDS (TQ_LOCAL_WINDOW_SIZE / WORD_BIT_SIZE)
#define NUM_WORDS BITS_TO_LONGS(TQ_LOCAL_WINDOW_SIZE)


#define LOG_BUF_LEN 8192	  /* has to be a power of 2 */
#define LOG_BUF_LEN 8192	  /* has to be a power of 2 */


+3 −3
Original line number Original line Diff line number Diff line
@@ -52,7 +52,7 @@ void slide_own_bcast_window(struct hard_iface *hard_iface)


			bit_get_packet(bat_priv, word, 1, 0);
			bit_get_packet(bat_priv, word, 1, 0);
			orig_node->bcast_own_sum[hard_iface->if_num] =
			orig_node->bcast_own_sum[hard_iface->if_num] =
				bit_packet_count(word);
				bitmap_weight(word, TQ_LOCAL_WINDOW_SIZE);
			spin_unlock_bh(&orig_node->ogm_cnt_lock);
			spin_unlock_bh(&orig_node->ogm_cnt_lock);
		}
		}
		rcu_read_unlock();
		rcu_read_unlock();
@@ -1047,7 +1047,7 @@ int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
	spin_lock_bh(&orig_node->bcast_seqno_lock);
	spin_lock_bh(&orig_node->bcast_seqno_lock);


	/* check whether the packet is a duplicate */
	/* check whether the packet is a duplicate */
	if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
	if (bat_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
			 ntohl(bcast_packet->seqno)))
			 ntohl(bcast_packet->seqno)))
		goto spin_unlock;
		goto spin_unlock;


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