diff options
Diffstat (limited to 'drivers/staging/batman-adv/bitarray.c')
| -rw-r--r-- | drivers/staging/batman-adv/bitarray.c | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/drivers/staging/batman-adv/bitarray.c b/drivers/staging/batman-adv/bitarray.c deleted file mode 100644 index 3c67f5f42b2..00000000000 --- a/drivers/staging/batman-adv/bitarray.c +++ /dev/null @@ -1,177 +0,0 @@ -/* - * Copyright (C) 2006-2009 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 "log.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, uint16_t last_seqno, - uint16_t curr_seqno) -{ - int16_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. */ -void bit_shift(TYPE_OF_WORD *seq_bits, int32_t n) -{ - int32_t word_offset, word_num; - int32_t i; - - if (n <= 0) - 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; -} - - -/* receive and process one packet, returns 1 if received seq_num is considered - * new, 0 if old */ -char bit_get_packet(TYPE_OF_WORD *seq_bits, int16_t seq_num_diff, - int8_t set_mark) -{ - int i; - - /* we already got a sequence number higher than this one, so we just - * mark it. this should wrap around the integer just fine */ - if ((seq_num_diff < 0) && (seq_num_diff >= -TQ_LOCAL_WINDOW_SIZE)) { - if (set_mark) - bit_mark(seq_bits, -seq_num_diff); - return 0; - } - - /* it seems we missed a lot of packets or the other host restarted */ - if ((seq_num_diff > TQ_LOCAL_WINDOW_SIZE) || - (seq_num_diff < -TQ_LOCAL_WINDOW_SIZE)) { - - if (seq_num_diff > TQ_LOCAL_WINDOW_SIZE) - debug_log(LOG_TYPE_BATMAN, - "We missed a lot of packets (%i) !\n", - seq_num_diff-1); - - if (-seq_num_diff > TQ_LOCAL_WINDOW_SIZE) - debug_log(LOG_TYPE_BATMAN, - "Other host probably restarted !\n"); - - for (i = 0; i < NUM_WORDS; i++) - seq_bits[i] = 0; - - if (set_mark) - seq_bits[0] = 1; /* we only have the latest packet */ - } else { - bit_shift(seq_bits, seq_num_diff); - - if (set_mark) - bit_mark(seq_bits, 0); - } - - return 1; -} - -/* count the hamming weight, how many good packets did we receive? just count - * the 1's. The inner loop uses the Kernighan algorithm, see - * http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetKernighan - */ -int bit_packet_count(TYPE_OF_WORD *seq_bits) -{ - int i, hamming = 0; - TYPE_OF_WORD word; - - for (i = 0; i < NUM_WORDS; i++) { - word = seq_bits[i]; - - while (word) { - word &= word-1; - hamming++; - } - } - return hamming; -} |