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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-22 14:43:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-22 14:43:13 -0700 |
| commit | 951cc93a7493a81a47e20231441bc6cf17c98a37 (patch) | |
| tree | f53934f0f225e0215a85c8c59af4c6513e89e3f1 /lib/crc8.c | |
| parent | a7e1aabb28e8154ce987b622fd78d80a1ca39361 (diff) | |
| parent | 415b3334a21aa67806c52d1acf4e72e14f7f402f (diff) | |
| download | olio-linux-3.10-951cc93a7493a81a47e20231441bc6cf17c98a37.tar.xz olio-linux-3.10-951cc93a7493a81a47e20231441bc6cf17c98a37.zip | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1287 commits)
icmp: Fix regression in nexthop resolution during replies.
net: Fix ppc64 BPF JIT dependencies.
acenic: include NET_SKB_PAD headroom to incoming skbs
ixgbe: convert to ndo_fix_features
ixgbe: only enable WoL for magic packet by default
ixgbe: remove ifdef check for non-existent define
ixgbe: Pass staterr instead of re-reading status and error bits from descriptor
ixgbe: Move interrupt related values out of ring and into q_vector
ixgbe: add structure for containing RX/TX rings to q_vector
ixgbe: inline the ixgbe_maybe_stop_tx function
ixgbe: Update ATR to use recorded TX queues instead of CPU for routing
igb: Fix for DH89xxCC near end loopback test
e1000: always call e1000_check_for_link() on e1000_ce4100 MACs.
netxen: add fw version compatibility check
be2net: request native mode each time the card is reset
ipv4: Constrain UFO fragment sizes to multiples of 8 bytes
virtio_net: Fix panic in virtnet_remove
ipv6: make fragment identifications less predictable
ipv6: unshare inetpeers
can: make function can_get_bittiming static
...
Diffstat (limited to 'lib/crc8.c')
| -rw-r--r-- | lib/crc8.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/lib/crc8.c b/lib/crc8.c new file mode 100644 index 00000000000..87b59cafdb8 --- /dev/null +++ b/lib/crc8.c @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2011 Broadcom Corporation + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY + * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION + * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/crc8.h> +#include <linux/printk.h> + +/* + * crc8_populate_msb - fill crc table for given polynomial in reverse bit order. + * + * table: table to be filled. + * polynomial: polynomial for which table is to be filled. + */ +void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial) +{ + int i, j; + const u8 msbit = 0x80; + u8 t = msbit; + + table[0] = 0; + + for (i = 1; i < CRC8_TABLE_SIZE; i *= 2) { + t = (t << 1) ^ (t & msbit ? polynomial : 0); + for (j = 0; j < i; j++) + table[i+j] = table[j] ^ t; + } +} +EXPORT_SYMBOL(crc8_populate_msb); + +/* + * crc8_populate_lsb - fill crc table for given polynomial in regular bit order. + * + * table: table to be filled. + * polynomial: polynomial for which table is to be filled. + */ +void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial) +{ + int i, j; + u8 t = 1; + + table[0] = 0; + + for (i = (CRC8_TABLE_SIZE >> 1); i; i >>= 1) { + t = (t >> 1) ^ (t & 1 ? polynomial : 0); + for (j = 0; j < CRC8_TABLE_SIZE; j += 2*i) + table[i+j] = table[j] ^ t; + } +} +EXPORT_SYMBOL(crc8_populate_lsb); + +/* + * crc8 - calculate a crc8 over the given input data. + * + * table: crc table used for calculation. + * pdata: pointer to data buffer. + * nbytes: number of bytes in data buffer. + * crc: previous returned crc8 value. + */ +u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc) +{ + /* loop over the buffer data */ + while (nbytes-- > 0) + crc = table[(crc ^ *pdata++) & 0xff]; + + return crc; +} +EXPORT_SYMBOL(crc8); + +MODULE_DESCRIPTION("CRC8 (by Williams, Ross N.) function"); +MODULE_AUTHOR("Broadcom Corporation"); +MODULE_LICENSE("Dual BSD/GPL"); |