s390/qeth: simplify max MTU handling

When the MPC initialization code discovers the HW-specific max MTU,
apply the resulting changes straight to the netdevice.

If this is the device's first initialization, also set its MTU
(HiperSockets: the max MTU; else: a layer-specific default value).
Then cap the current MTU by the new max MTU.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 04b900c..6f02a6c 100644 (file)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -660,8 +660,6 @@ struct qeth_card_info {
        int mac_bits;
        enum qeth_card_types type;
        enum qeth_link_types link_type;
-       int initial_mtu;
-       int max_mtu;
        int broadcast_capable;
        int unique_id;
        bool layer_enforced;

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 39c4297..ab3d63f 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2278,19 +2278,42 @@ static int qeth_cm_setup(struct qeth_card *card)
 
 }
 
-static int qeth_get_initial_mtu_for_card(struct qeth_card *card)
+static int qeth_update_max_mtu(struct qeth_card *card, unsigned int max_mtu)
 {
-       switch (card->info.type) {
-       case QETH_CARD_TYPE_IQD:
-               return card->info.max_mtu;
-       case QETH_CARD_TYPE_OSD:
-       case QETH_CARD_TYPE_OSX:
-               if (!card->options.layer2)
-                       return ETH_DATA_LEN - 8; /* L3: allow for LLC + SNAP */
-               /* fall through */
-       default:
-               return ETH_DATA_LEN;
+       struct net_device *dev = card->dev;
+       unsigned int new_mtu;
+
+       if (!max_mtu) {
+               /* IQD needs accurate max MTU to set up its RX buffers: */
+               if (IS_IQD(card))
+                       return -EINVAL;
+               /* tolerate quirky HW: */
+               max_mtu = ETH_MAX_MTU;
+       }
+
+       rtnl_lock();
+       if (IS_IQD(card)) {
+               /* move any device with default MTU to new max MTU: */
+               new_mtu = (dev->mtu == dev->max_mtu) ? max_mtu : dev->mtu;
+
+               /* adjust RX buffer size to new max MTU: */
+               card->qdio.in_buf_size = max_mtu + 2 * PAGE_SIZE;
+               if (dev->max_mtu && dev->max_mtu != max_mtu)
+                       qeth_free_qdio_buffers(card);
+       } else {
+               if (dev->mtu)
+                       new_mtu = dev->mtu;
+               /* default MTUs for first setup: */
+               else if (card->options.layer2)
+                       new_mtu = ETH_DATA_LEN;
+               else
+                       new_mtu = ETH_DATA_LEN - 8; /* allow for LLC + SNAP */
        }
+
+       dev->max_mtu = max_mtu;
+       dev->mtu = min(new_mtu, max_mtu);
+       rtnl_unlock();
+       return 0;
 }
 
 static int qeth_get_mtu_outof_framesize(int framesize)
@@ -2316,8 +2339,7 @@ static int qeth_mtu_is_valid(struct qeth_card *card, int mtu)
        case QETH_CARD_TYPE_OSM:
        case QETH_CARD_TYPE_OSX:
        case QETH_CARD_TYPE_IQD:
-               return ((mtu >= 576) &&
-                       (mtu <= card->info.max_mtu));
+               return ((mtu >= 576) && (mtu <= card->dev->max_mtu));
        case QETH_CARD_TYPE_OSN:
        default:
                return 1;
@@ -2342,28 +2364,10 @@ static int qeth_ulp_enable_cb(struct qeth_card *card, struct qeth_reply *reply,
        if (card->info.type == QETH_CARD_TYPE_IQD) {
                memcpy(&framesize, QETH_ULP_ENABLE_RESP_MAX_MTU(iob->data), 2);
                mtu = qeth_get_mtu_outof_framesize(framesize);
-               if (!mtu) {
-                       iob->rc = -EINVAL;
-                       QETH_DBF_TEXT_(SETUP, 2, "  rc%d", iob->rc);
-                       return 0;
-               }
-               if (card->info.initial_mtu && (card->info.initial_mtu != mtu)) {
-                       /* frame size has changed */
-                       if ((card->dev->mtu == card->info.initial_mtu) ||
-                           (card->dev->mtu > mtu))
-                               card->dev->mtu = mtu;
-                       qeth_free_qdio_buffers(card);
-               }
-               card->info.initial_mtu = mtu;
-               card->info.max_mtu = mtu;
-               card->qdio.in_buf_size = mtu + 2 * PAGE_SIZE;
        } else {
-               card->info.max_mtu = *(__u16 *)QETH_ULP_ENABLE_RESP_MAX_MTU(
-                       iob->data);
-               card->info.initial_mtu = min(card->info.max_mtu,
-                                       qeth_get_initial_mtu_for_card(card));
-               card->qdio.in_buf_size = QETH_IN_BUF_SIZE_DEFAULT;
+               mtu = *(__u16 *)QETH_ULP_ENABLE_RESP_MAX_MTU(iob->data);
        }
+       *(u16 *)reply->param = mtu;
 
        memcpy(&len, QETH_ULP_ENABLE_RESP_DIFINFO_LEN(iob->data), 2);
        if (len >= QETH_MPC_DIFINFO_LEN_INDICATES_LINK_TYPE) {
@@ -2382,6 +2386,7 @@ static int qeth_ulp_enable(struct qeth_card *card)
        int rc;
        char prot_type;
        struct qeth_cmd_buffer *iob;
+       u16 max_mtu;
 
        /*FIXME: trace view callbacks*/
        QETH_DBF_TEXT(SETUP, 2, "ulpenabl");
@@ -2404,9 +2409,10 @@ static int qeth_ulp_enable(struct qeth_card *card)
        memcpy(QETH_ULP_ENABLE_FILTER_TOKEN(iob->data),
               &card->token.ulp_filter_w, QETH_MPC_TOKEN_LENGTH);
        rc = qeth_send_control_data(card, ULP_ENABLE_SIZE, iob,
-                                   qeth_ulp_enable_cb, NULL);
-       return rc;
-
+                                   qeth_ulp_enable_cb, &max_mtu);
+       if (rc)
+               return rc;
+       return qeth_update_max_mtu(card, max_mtu);
 }
 
 static int qeth_ulp_setup_cb(struct qeth_card *card, struct qeth_reply *reply,
@@ -5691,7 +5697,9 @@ static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
        dev->ml_priv = card;
        dev->watchdog_timeo = QETH_TX_TIMEOUT;
        dev->min_mtu = 64;
-       dev->max_mtu = ETH_MAX_MTU;
+        /* initialized when device first goes online: */
+       dev->max_mtu = 0;
+       dev->mtu = 0;
        SET_NETDEV_DEV(dev, &card->gdev->dev);
        netif_carrier_off(dev);
        return dev;

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 8392fc7..00d8bb1 100644 (file)
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -944,7 +944,6 @@ static int qeth_l2_setup_netdev(struct qeth_card *card)
                return 0;
 
        card->dev->priv_flags |= IFF_UNICAST_FLT;
-       card->dev->mtu = card->info.initial_mtu;
        card->dev->netdev_ops = &qeth_l2_netdev_ops;
        if (card->info.type == QETH_CARD_TYPE_OSN) {
                card->dev->ethtool_ops = &qeth_l2_osn_ops;

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 72c8f32..e5fa8e5 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2579,7 +2579,6 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
        } else
                return -ENODEV;
 
-       card->dev->mtu = card->info.initial_mtu;
        card->dev->ethtool_ops = &qeth_l3_ethtool_ops;
        card->dev->priv_flags &= ~IFF_TX_SKB_SHARING;
        card->dev->needed_headroom = sizeof(struct qeth_hdr) - ETH_HLEN;