leon,greth: enable MAC filtering (promiscous mode, multicast)

It enabled promiscous mode or sets the multicast filter according
to the configuration and parameters to ioctl(SIOCSIFFLAGS),
ioctl(SIOCADDMULTI) and ioctl(SIOCDELMULTI).
On SIOCADDMULTI/SIOCDELMULTI requests the greth ioctl calls the
Ethernet helper functions ether_addmulti()/ether_delmulti() which
tells the greth driver when its required to update the MAC multicast
filtering.

The interface notifies support for multicast by setting IFF_MULTICAST.

The GRETH has two registers which contains a bit-mask of allowed MAC
addresses. The incomming MAC address is CRC:ed and the CRC is used as
an index into the bit-mask to determine to allow or drop the frame.

2 files changed, 105 insertions, 1 deletions

diff --git a/bsps/sparc/include/bsp/greth.h b/bsps/sparc/include/bsp/greth.h
index 9209d823e3..1c42c99ddc 100644
--- a/bsps/sparc/include/bsp/greth.h
+++ b/bsps/sparc/include/bsp/greth.h
@@ -24,6 +24,9 @@ typedef struct _greth_regs {
    volatile uint32_t mdio_ctrl;    /* MDIO control and status */
    volatile uint32_t txdesc;       /* Transmit descriptor pointer */
    volatile uint32_t rxdesc;       /* Receive descriptor pointer */
+   volatile uint32_t edcl;         /* EDCL IP register */
+   volatile uint32_t ht_msb;       /* Multicast MSB hash */
+   volatile uint32_t ht_lsb;       /* Multicast LSB hash */
 } greth_regs;
 
 #define GRETH_TOTAL_BD           128
@@ -83,8 +86,12 @@ typedef struct _greth_regs {
 #define GRETH_CTRL_RST          0x00000040 /* Reset MAC */
 #define GRETH_CTRL_SP           0x00000080 /* 100MBit speed mode */
 #define GRETH_CTRL_GB           0x00000100 /* 1GBit speed mode */
+#define GRETH_CTRL_MCE          0x00000800 /* Multicast Enable */
 #define GRETH_CTRL_DD           0x00001000 /* Disable EDCL Duplex Detection */
 #define GRETH_CTRL_ED           0x00004000 /* EDCL Disable */
+#define GRETH_CTRL_MC           0x02000000 /* Multicast available */
+#define GRETH_CTRL_ME           0x04000000 /* MDIO interrupts enabled */
+#define GRETH_CTRL_GA           0x08000000 /* Gigabit MAC available */
 
 /* Status Register */
 #define GRETH_STATUS_RXERR      0x00000001 /* Receive Error */
diff --git a/bsps/sparc/shared/net/greth.c b/bsps/sparc/shared/net/greth.c
index b2d2569b10..d2824516a0 100644
--- a/bsps/sparc/shared/net/greth.c
+++ b/bsps/sparc/shared/net/greth.c
@@ -194,6 +194,7 @@ struct greth_softc
    int auto_neg;
    unsigned int advmodes; /* advertise ethernet speed modes. 0 = all modes. */
    struct timespec auto_neg_time;
+   int mc_available;
 
    /*
     * Statistics
@@ -341,6 +342,78 @@ static void print_init_info(struct greth_softc *sc)
 #endif
 }
 
+/*
+ * Generates the hash words based on CRCs of the enabled MAC addresses that are
+ * allowed to be received. The allowed MAC addresses are maintained in a linked
+ * "multi-cast" list available in the arpcom structure.
+ *
+ * Returns the number of MAC addresses that were processed (in the list)
+ */
+static int
+greth_mac_filter_calc(struct arpcom *ac, uint32_t *msb, uint32_t *lsb)
+{
+    struct ether_multistep step;
+    struct ether_multi *enm;
+    int cnt = 0;
+    uint32_t crc, htindex, ht[2] = {0, 0};
+
+    /* Go through the Ethernet Multicast addresses one by one and add their
+     * CRC contribution to the MAC filter.
+     */
+    ETHER_FIRST_MULTI(step, ac, enm);
+    while (enm) {
+        crc = ether_crc32_be((uint8_t *)enm->enm_addrlo, 6);
+        htindex = crc & 0x3f;
+        ht[htindex >> 5] |= (1 << (htindex & 0x1F));
+        cnt++;
+        ETHER_NEXT_MULTI(step, enm);
+    }
+
+    if (cnt > 0) {
+        *msb = ht[1];
+        *lsb = ht[0];
+    }
+
+    return cnt;
+}
+
+/*
+ * Initialize the ethernet hardware
+ */
+static int greth_mac_filter_set(struct greth_softc *sc)
+{
+    struct ifnet *ifp = &sc->arpcom.ac_if;
+    uint32_t hash_msb, hash_lsb, ctrl;
+    SPIN_IRQFLAGS(flags);
+
+    hash_msb = 0;
+    hash_lsb = 0;
+    ctrl = 0;
+    if (ifp->if_flags & IFF_PROMISC) {
+        /* No need to enable multi-cast when promiscous mode accepts all */
+        ctrl |= GRETH_CTRL_PRO;
+    } else if(!sc->mc_available) {
+        return EINVAL; /* no hardware support for multicast filtering. */
+    } else if (ifp->if_flags & IFF_ALLMULTI) {
+        /* We should accept all multicast addresses */
+        ctrl |= GRETH_CTRL_MCE;
+        hash_msb = 0xFFFFFFFF;
+        hash_lsb = 0xFFFFFFFF;
+    } else if (greth_mac_filter_calc(&sc->arpcom, &hash_msb, &hash_lsb) > 0) {
+        /* Generate hash for MAC filtering out multicast addresses */
+        ctrl |= GRETH_CTRL_MCE;
+    } else {
+        /* Multicast list is empty .. disable multicast */
+    }
+    SPIN_LOCK_IRQ(&sc->devlock, flags);
+    sc->regs->ht_msb = hash_msb;
+    sc->regs->ht_lsb = hash_lsb;
+    sc->regs->ctrl = (sc->regs->ctrl & ~(GRETH_CTRL_PRO | GRETH_CTRL_MCE)) |
+                     ctrl;
+    SPIN_UNLOCK_IRQ(&sc->devlock, flags);
+
+    return 0;
+}
 
 /*
  * Initialize the ethernet hardware
@@ -1182,6 +1255,11 @@ greth_init (void *arg)
       }
 
     /*
+     * Setup promiscous/multi-cast MAC address filters if user enabled it
+     */
+    greth_mac_filter_set(sc);
+
+    /*
      * Tell the world that we're running.
      */
     ifp->if_flags |= IFF_RUNNING;
@@ -1240,6 +1318,7 @@ greth_ioctl (struct ifnet *ifp, ioctl_command_t command, caddr_t data)
 {
     struct greth_softc *sc = ifp->if_softc;
     int error = 0;
+    struct ifreq *ifr;
 
     switch (command)
       {
@@ -1273,8 +1352,21 @@ greth_ioctl (struct ifnet *ifp, ioctl_command_t command, caddr_t data)
 	  break;
 
 	  /*
-	   * FIXME: All sorts of multicast commands need to be added here!
+	   * Multicast commands: Enabling/disabling filtering of MAC addresses
 	   */
+      case SIOCADDMULTI:
+      case SIOCDELMULTI:
+      ifr = (struct ifreq *)data;
+      if (command == SIOCADDMULTI) {
+        error = ether_addmulti(ifr, &sc->arpcom);
+      } else {
+        error = ether_delmulti(ifr, &sc->arpcom);
+      }
+      if (error == ENETRESET) {
+        error = greth_mac_filter_set(sc);
+      }
+      break;
+
       default:
 	  error = EINVAL;
 	  break;
@@ -1336,6 +1428,8 @@ greth_interface_driver_attach (
     ifp->if_start = greth_start;
     ifp->if_output = ether_output;
     ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX;
+    if (sc->mc_available)
+        ifp->if_flags |= IFF_MULTICAST;
     if (ifp->if_snd.ifq_maxlen == 0)
 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
 
@@ -1540,6 +1634,9 @@ int greth_device_init(struct greth_softc *sc)
     if ( value )
         sc->advmodes = value->i;
 
+    /* Check if multicast support is available */
+    sc->mc_available = sc->regs->ctrl & GRETH_CTRL_MC;
+
     return 0;
 }