diff options
Diffstat (limited to 'drivers/staging/batman-adv/bitarray.c')
| -rw-r--r-- | drivers/staging/batman-adv/bitarray.c | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/drivers/staging/batman-adv/bitarray.c b/drivers/staging/batman-adv/bitarray.c deleted file mode 100644 index 814274fbaa2f..000000000000 --- a/drivers/staging/batman-adv/bitarray.c +++ /dev/null @@ -1,201 +0,0 @@ -/* - * Copyright (C) 2006-2010 B.A.T.M.A.N. contributors: - * - * Simon Wunderlich, Marek Lindner - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301, USA - * - */ - -#include "main.h" -#include "bitarray.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 */ -uint8_t get_bit_status(TYPE_OF_WORD *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 (seq_bits[word_num] & 1 << word_offset) - return 1; - else - return 0; - } -} - -/* turn corresponding bit on, so we can remember that we got the packet */ -void bit_mark(TYPE_OF_WORD *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; - - seq_bits[word_num] |= 1 << word_offset; /* turn the position on */ -} - -/* shift the packet array by n places. */ -static void bit_shift(TYPE_OF_WORD *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 - * it's position */ - /* for our example that would be: word[0] = 9800 + 0076 = - * 9876 */ - } - /* now for our last word, i==word_num, we only have the it's "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(TYPE_OF_WORD *seq_bits) -{ - int i; - for (i = 0; i < NUM_WORDS; i++) - seq_bits[i] = 0; -} - - -/* receive and process one packet within the sequence number window. - * - * returns: - * 1 if the window was moved (either new or very old) - * 0 if the window was not moved/shifted. - */ -char bit_get_packet(void *priv, TYPE_OF_WORD *seq_bits, - int32_t seq_num_diff, int8_t set_mark) -{ - struct bat_priv *bat_priv = (struct bat_priv *)priv; - - /* sequence number is slightly older. We already got a sequence number - * higher than this one, so we just mark it. */ - - if ((seq_num_diff <= 0) && (seq_num_diff > -TQ_LOCAL_WINDOW_SIZE)) { - if (set_mark) - bit_mark(seq_bits, -seq_num_diff); - return 0; - } - - /* sequence number is slightly newer, so we shift the window and - * set the mark if required */ - - if ((seq_num_diff > 0) && (seq_num_diff < TQ_LOCAL_WINDOW_SIZE)) { - bit_shift(seq_bits, seq_num_diff); - - if (set_mark) - bit_mark(seq_bits, 0); - return 1; - } - - /* sequence number is much newer, probably missed a lot of packets */ - - if ((seq_num_diff >= TQ_LOCAL_WINDOW_SIZE) - || (seq_num_diff < EXPECTED_SEQNO_RANGE)) { - bat_dbg(DBG_BATMAN, bat_priv, - "We missed a lot of packets (%i) !\n", - seq_num_diff - 1); - bit_reset_window(seq_bits); - if (set_mark) - bit_mark(seq_bits, 0); - return 1; - } - - /* received a much older packet. The other host either restarted - * or the old packet got delayed somewhere in the network. The - * packet should be dropped without calling this function if the - * seqno window is protected. */ - - if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) - || (seq_num_diff >= EXPECTED_SEQNO_RANGE)) { - - bat_dbg(DBG_BATMAN, bat_priv, - "Other host probably restarted!\n"); - - bit_reset_window(seq_bits); - if (set_mark) - bit_mark(seq_bits, 0); - - return 1; - } - - /* never reached */ - return 0; -} - -/* count the hamming weight, how many good packets did we receive? just count - * the 1's. - */ -int bit_packet_count(TYPE_OF_WORD *seq_bits) -{ - int i, hamming = 0; - - for (i = 0; i < NUM_WORDS; i++) - hamming += hweight_long(seq_bits[i]); - - return hamming; -} |