Date: Thu, 3 Jun 2004 15:54:52 +0000 (UTC) From: naddy@mips.inka.de (Christian Weisgerber) To: freebsd-current@freebsd.org Subject: Re: Network driver jumbo patch (affects multicast) Message-ID: <c9nhkc$2lc1$1@kemoauc.mips.inka.de> References: <c9ltb3$13cb$1@kemoauc.mips.inka.de> <20040603012501.GA5035@thingy.tbd.co.nz> <20040603140245.GA79548@kemoauc.mips.inka.de> <20040603142944.GJ9228@elvis.mu.org>
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Maxime Henrion <mux@freebsd.org> wrote:
> I tend to disagree, I find this comment a valuable technical information.
If you guys feel strongly about this, we can preserve it.
Index: pci/if_xl.c
===================================================================
RCS file: /home/ncvs/src/sys/pci/if_xl.c,v
retrieving revision 1.170
diff -u -r1.170 if_xl.c
--- pci/if_xl.c 30 May 2004 20:00:41 -0000 1.170
+++ pci/if_xl.c 3 Jun 2004 15:36:34 -0000
@@ -253,7 +253,6 @@
static void xl_setcfg (struct xl_softc *);
static void xl_setmode (struct xl_softc *, int);
-static uint32_t xl_mchash (const uint8_t *);
static void xl_setmulti (struct xl_softc *);
static void xl_setmulti_hash (struct xl_softc *);
static void xl_reset (struct xl_softc *);
@@ -812,44 +811,6 @@
}
/*
- * This routine is taken from the 3Com Etherlink XL manual,
- * page 10-7. It calculates a CRC of the supplied multicast
- * group address and returns the lower 8 bits, which are used
- * as the multicast filter position.
- * Note: the 3c905B currently only supports a 64-bit hash table,
- * which means we really only need 6 bits, but the manual indicates
- * that future chip revisions will have a 256-bit hash table,
- * hence the routine is set up to calculate 8 bits of position
- * info in case we need it some day.
- * Note II, The Sequel: _CURRENT_ versions of the 3c905B have a
- * 256 bit hash table. This means we have to use all 8 bits regardless.
- * On older cards, the upper 2 bits will be ignored. Grrrr....
- */
-static u_int32_t
-xl_mchash(addr)
- const uint8_t *addr;
-{
- uint32_t crc, carry;
- int idx, bit;
- uint8_t data;
-
- /* Compute CRC for the address value. */
- crc = 0xFFFFFFFF; /* initial value */
-
- for (idx = 0; idx < 6; idx++) {
- for (data = *addr++, bit = 0; bit < 8; bit++, data >>= 1) {
- carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01);
- crc <<= 1;
- if (carry)
- crc = (crc ^ 0x04c11db6) | carry;
- }
- }
-
- /* return the filter bit position */
- return(crc & 0x000000FF);
-}
-
-/*
* NICs older than the 3c905B have only one multicast option, which
* is to enable reception of all multicast frames.
*/
@@ -920,7 +881,20 @@
TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
if (ifma->ifma_addr->sa_family != AF_LINK)
continue;
- h = xl_mchash(LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
+ /*
+ * Note: the 3c905B currently only supports a 64-bit hash
+ * table, which means we really only need 6 bits, but the
+ * manual indicates that future chip revisions will have a
+ * 256-bit hash table, hence the routine is set up to
+ * calculate 8 bits of position info in case we need it some
+ * day.
+ * Note II, The Sequel: _CURRENT_ versions of the 3c905B have
+ * a 256 bit hash table. This means we have to use all 8 bits
+ * regardless. On older cards, the upper 2 bits will be
+ * ignored. Grrrr....
+ */
+ h = ether_crc32_be(LLADDR((struct sockaddr_dl *)
+ ifma->ifma_addr), ETHER_ADDR_LEN) & 0xFF;
CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_HASH|XL_HASH_SET|h);
mcnt++;
}
--
Christian "naddy" Weisgerber naddy@mips.inka.de
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