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mv643xx_eth: massively simplify multicast address crc8 computation

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Replace the 70-line crc8 computation (used for multicast address
filtering tables) by a 5-line version.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Dale Farnsworth <dale@farnsworth.org>
This commit is contained in:
Lennert Buytenhek 2008-06-01 11:43:32 +02:00
parent 1682005477
commit 69876569bb
1 changed files with 21 additions and 74 deletions
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95
drivers/net/mv643xx_eth.c
View file

@ -1141,16 +1141,29 @@ static int mv643xx_eth_set_mac_address(struct net_device *dev, void *addr)
return 0;
}
static int addr_crc(unsigned char *addr)
{
int crc = 0;
int i;
for (i = 0; i < 6; i++) {
int j;
crc = (crc ^ addr[i]) << 8;
for (j = 7; j >= 0; j--) {
if (crc & (0x100 << j))
crc ^= 0x107 << j;
}
}
return crc;
}
static void mc_addr(struct mv643xx_eth_private *mp, unsigned char *addr)
{
unsigned int port_num = mp->port_num;
unsigned int mac_h;
unsigned int mac_l;
unsigned char crc_result = 0;
int table;
int mac_array[48];
int crc[8];
int i;
int crc;
if ((addr[0] == 0x01) && (addr[1] == 0x00) &&
(addr[2] == 0x5E) && (addr[3] == 0x00) && (addr[4] == 0x00)) {
@ -1159,76 +1172,10 @@ static void mc_addr(struct mv643xx_eth_private *mp, unsigned char *addr)
return;
}
/* Calculate CRC-8 out of the given address */
mac_h = (addr[0] << 8) | (addr[1]);
mac_l = (addr[2] << 24) | (addr[3] << 16) |
(addr[4] << 8) | (addr[5] << 0);
for (i = 0; i < 32; i++)
mac_array[i] = (mac_l >> i) & 0x1;
for (i = 32; i < 48; i++)
mac_array[i] = (mac_h >> (i - 32)) & 0x1;
crc[0] = mac_array[45] ^ mac_array[43] ^ mac_array[40] ^ mac_array[39] ^
mac_array[35] ^ mac_array[34] ^ mac_array[31] ^ mac_array[30] ^
mac_array[28] ^ mac_array[23] ^ mac_array[21] ^ mac_array[19] ^
mac_array[18] ^ mac_array[16] ^ mac_array[14] ^ mac_array[12] ^
mac_array[8] ^ mac_array[7] ^ mac_array[6] ^ mac_array[0];
crc[1] = mac_array[46] ^ mac_array[45] ^ mac_array[44] ^ mac_array[43] ^
mac_array[41] ^ mac_array[39] ^ mac_array[36] ^ mac_array[34] ^
mac_array[32] ^ mac_array[30] ^ mac_array[29] ^ mac_array[28] ^
mac_array[24] ^ mac_array[23] ^ mac_array[22] ^ mac_array[21] ^
mac_array[20] ^ mac_array[18] ^ mac_array[17] ^ mac_array[16] ^
mac_array[15] ^ mac_array[14] ^ mac_array[13] ^ mac_array[12] ^
mac_array[9] ^ mac_array[6] ^ mac_array[1] ^ mac_array[0];
crc[2] = mac_array[47] ^ mac_array[46] ^ mac_array[44] ^ mac_array[43] ^
mac_array[42] ^ mac_array[39] ^ mac_array[37] ^ mac_array[34] ^
mac_array[33] ^ mac_array[29] ^ mac_array[28] ^ mac_array[25] ^
mac_array[24] ^ mac_array[22] ^ mac_array[17] ^ mac_array[15] ^
mac_array[13] ^ mac_array[12] ^ mac_array[10] ^ mac_array[8] ^
mac_array[6] ^ mac_array[2] ^ mac_array[1] ^ mac_array[0];
crc[3] = mac_array[47] ^ mac_array[45] ^ mac_array[44] ^ mac_array[43] ^
mac_array[40] ^ mac_array[38] ^ mac_array[35] ^ mac_array[34] ^
mac_array[30] ^ mac_array[29] ^ mac_array[26] ^ mac_array[25] ^
mac_array[23] ^ mac_array[18] ^ mac_array[16] ^ mac_array[14] ^
mac_array[13] ^ mac_array[11] ^ mac_array[9] ^ mac_array[7] ^
mac_array[3] ^ mac_array[2] ^ mac_array[1];
crc[4] = mac_array[46] ^ mac_array[45] ^ mac_array[44] ^ mac_array[41] ^
mac_array[39] ^ mac_array[36] ^ mac_array[35] ^ mac_array[31] ^
mac_array[30] ^ mac_array[27] ^ mac_array[26] ^ mac_array[24] ^
mac_array[19] ^ mac_array[17] ^ mac_array[15] ^ mac_array[14] ^
mac_array[12] ^ mac_array[10] ^ mac_array[8] ^ mac_array[4] ^
mac_array[3] ^ mac_array[2];
crc[5] = mac_array[47] ^ mac_array[46] ^ mac_array[45] ^ mac_array[42] ^
mac_array[40] ^ mac_array[37] ^ mac_array[36] ^ mac_array[32] ^
mac_array[31] ^ mac_array[28] ^ mac_array[27] ^ mac_array[25] ^
mac_array[20] ^ mac_array[18] ^ mac_array[16] ^ mac_array[15] ^
mac_array[13] ^ mac_array[11] ^ mac_array[9] ^ mac_array[5] ^
mac_array[4] ^ mac_array[3];
crc[6] = mac_array[47] ^ mac_array[46] ^ mac_array[43] ^ mac_array[41] ^
mac_array[38] ^ mac_array[37] ^ mac_array[33] ^ mac_array[32] ^
mac_array[29] ^ mac_array[28] ^ mac_array[26] ^ mac_array[21] ^
mac_array[19] ^ mac_array[17] ^ mac_array[16] ^ mac_array[14] ^
mac_array[12] ^ mac_array[10] ^ mac_array[6] ^ mac_array[5] ^
mac_array[4];
crc[7] = mac_array[47] ^ mac_array[44] ^ mac_array[42] ^ mac_array[39] ^
mac_array[38] ^ mac_array[34] ^ mac_array[33] ^ mac_array[30] ^
mac_array[29] ^ mac_array[27] ^ mac_array[22] ^ mac_array[20] ^
mac_array[18] ^ mac_array[17] ^ mac_array[15] ^ mac_array[13] ^
mac_array[11] ^ mac_array[7] ^ mac_array[6] ^ mac_array[5];
for (i = 0; i < 8; i++)
crc_result = crc_result | (crc[i] << i);
crc = addr_crc(addr);
table = OTHER_MCAST_TABLE(port_num);
set_filter_table_entry(mp, table, crc_result);
set_filter_table_entry(mp, table, crc);
}
static void set_multicast_list(struct net_device *dev)