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Date: Tue, 3 Jun 2008 13:02:40 +0200
From: Lennert Buytenhek <buytenh@...tstofly.org>
To: Dale Farnsworth <dale@...nsworth.org>
Cc: netdev@...r.kernel.org
Subject: [PATCH 25/39] mv643xx_eth: massively simplify multicast address crc8 computation
Replace the 70-line crc8 computation (used for multicast address
filtering tables) by a 5-line version.
Signed-off-by: Lennert Buytenhek <buytenh@...vell.com>
---
drivers/net/mv643xx_eth.c | 95 ++++++++++-----------------------------------
1 files changed, 21 insertions(+), 74 deletions(-)
diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index b3be8fe..beb4cf9 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -1132,16 +1132,29 @@ 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 *mep, unsigned char *addr)
{
unsigned int port_num = mep->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)) {
@@ -1150,76 +1163,10 @@ static void mc_addr(struct mv643xx_eth_private *mep, 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(mep, table, crc_result);
+ set_filter_table_entry(mep, table, crc);
}
static void set_multicast_list(struct net_device *dev)
--
1.5.3.4
--
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