diff options
Diffstat (limited to 'sys/dev/xe/if_xe.c')
| -rw-r--r-- | sys/dev/xe/if_xe.c | 55 |
1 files changed, 28 insertions, 27 deletions
diff --git a/sys/dev/xe/if_xe.c b/sys/dev/xe/if_xe.c index 9609410..3e51011 100644 --- a/sys/dev/xe/if_xe.c +++ b/sys/dev/xe/if_xe.c @@ -22,13 +22,7 @@ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. - * - * $Id: if_xe.c,v 1.20 1999/06/13 19:17:40 scott Exp $ */ - -#include <sys/cdefs.h> -__FBSDID("$FreeBSD$"); - /* * Portions of this software were derived from Werner Koch's xirc2ps driver * for Linux under the terms of the following license (from v1.30 of the @@ -62,6 +56,9 @@ __FBSDID("$FreeBSD$"); * OF THE POSSIBILITY OF SUCH DAMAGE. */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + /* * FreeBSD device driver for Xircom CreditCard PCMCIA Ethernet adapters. The * following cards are currently known to work with the driver: @@ -166,7 +163,7 @@ static void xe_enable_intr (struct xe_softc *scp); static void xe_disable_intr (struct xe_softc *scp); static void xe_set_multicast (struct xe_softc *scp); static void xe_set_addr (struct xe_softc *scp, u_int8_t* addr, unsigned idx); -static void xe_set_hash (struct xe_softc *scp, u_int8_t* addr); +static void xe_mchash (struct xe_softc *scp, caddr_t addr); static int xe_pio_write_packet (struct xe_softc *scp, struct mbuf *mbp); /* @@ -1302,7 +1299,7 @@ xe_set_multicast(struct xe_softc *scp) { else if (scp->mohawk) /* Use hash filter on Mohawk and Dingo */ - xe_set_hash(scp, LLADDR((struct sockaddr_dl *)maddr->ifma_addr)); + xe_mchash(scp, LLADDR((struct sockaddr_dl *)maddr->ifma_addr)); else /* Nowhere else to put them on CE2 */ break; @@ -1415,46 +1412,50 @@ xe_set_addr(struct xe_softc *scp, u_int8_t* addr, unsigned idx) { * address. */ static void -xe_set_hash(struct xe_softc* scp, u_int8_t* addr) { +xe_mchash(struct xe_softc* scp, caddr_t addr) { u_int32_t crc = 0xffffffff; - u_int8_t bit, byte, crc31, idx; - unsigned i, j; + int idx, bit; + u_int8_t carry, byte, data, crc31, hash; /* Compute CRC of the address -- standard Ethernet CRC function */ - for (i = 0; i < 6; i++) { - byte = addr[i]; - for (j = 1; j <= 8; j++) { + for (data = *addr++, idx = 0; idx < 6; idx++, data >>= 1) { + for (bit = 1; bit <= 8; bit++) { if (crc & 0x80000000) crc31 = 0x01; else crc31 = 0; - bit = crc31 ^ (byte & 0x01); + carry = crc31 ^ (data & 0x01); crc <<= 1; - byte >>= 1; - if (bit) - crc = (crc ^ XE_CRC_POLY)|1; + data >>= 1; + crc = (crc ^ XE_CRC_POLY) | (carry|0x1); } } DEVPRINTF(3, (scp->dev, "set_hash: CRC = 0x%08x\n", crc)); - /* Hash table index = 6 msbs of CRC, reversed */ - for (i = 0, idx = 0; i < 6; i++) { - idx >>= 1; + /* + * Convert a CRC into an index into the multicast hash table. What we do is + * take the most-significant 6 bits of the CRC, reverse them, and use that as + * the bit number in the hash table. Bits 5:3 of the result give the byte + * within the table (0-7); bits 2:0 give the bit number within that byte (also + * 0-7), ie. the number of shifts needed to get it into the lsb position. + */ + for (idx = 0, hash = 0; idx < 6; idx++) { + hash >>= 1; if (crc & 0x80000000) { - idx |= 0x20; + hash |= 0x20; } crc <<= 1; } - /* Top 3 bits of idx give register - 8, bottom 3 give bit within register */ - byte = idx >> 3 | 0x08; - bit = 0x01 << (idx & 0x07); + /* Top 3 bits of hash give register - 8, bottom 3 give bit within register */ + byte = hash >> 3 | 0x08; + carry = 0x01 << (hash & 0x07); - DEVPRINTF(3, (scp->dev, "set_hash: idx = 0x%02x, byte = 0x%02x, bit = 0x%02x\n", idx, byte, bit)); + DEVPRINTF(3, (scp->dev, "set_hash: hash = 0x%02x, byte = 0x%02x, carry = 0x%02x\n", hash, byte, carry)); XE_SELECT_PAGE(0x58); - XE_OUTB(byte, XE_INB(byte) | bit); + XE_OUTB(byte, XE_INB(byte) | carry); } |
