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>
diff --git a/net/batman-adv/bitarray.c b/net/batman-adv/bitarray.c
index 6d0aa21..07ae6e1 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 @@
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 @@
* 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 @@
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 @@
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 @@
/* 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;
-}