ibmveth: Implement ethtool hooks to enable/disable checksum offload

This patch adds the appropriate ethtool hooks to allow for enabling/disabling
of hypervisor assisted checksum offload for TCP.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 124 insertions, 2 deletions

diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index 9353890dcda0..9c16928e20ed 100644
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -652,12 +652,132 @@ static u32 netdev_get_link(struct net_device *dev) {
         return 1;
 }
 
+static void ibmveth_set_rx_csum_flags(struct net_device *dev, u32 data)
+{
+        struct ibmveth_adapter *adapter = dev->priv;
+
+        if (data)
+                adapter->rx_csum = 1;
+        else {
+                /*
+                 * Since the ibmveth firmware interface does not have the concept of
+                 * separate tx/rx checksum offload enable, if rx checksum is disabled
+                 * we also have to disable tx checksum offload. Once we disable rx
+                 * checksum offload, we are no longer allowed to send tx buffers that
+                 * are not properly checksummed.
+                 */
+                adapter->rx_csum = 0;
+                dev->features &= ~NETIF_F_IP_CSUM;
+        }
+}
+
+static void ibmveth_set_tx_csum_flags(struct net_device *dev, u32 data)
+{
+        struct ibmveth_adapter *adapter = dev->priv;
+
+        if (data) {
+                dev->features |= NETIF_F_IP_CSUM;
+                adapter->rx_csum = 1;
+        } else
+                dev->features &= ~NETIF_F_IP_CSUM;
+}
+
+static int ibmveth_set_csum_offload(struct net_device *dev, u32 data,
+                                    void (*done) (struct net_device *, u32))
+{
+        struct ibmveth_adapter *adapter = dev->priv;
+        union ibmveth_illan_attributes set_attr, clr_attr, ret_attr;
+        long ret;
+        int rc1 = 0, rc2 = 0;
+        int restart = 0;
+
+        if (netif_running(dev)) {
+                restart = 1;
+                adapter->pool_config = 1;
+                ibmveth_close(dev);
+                adapter->pool_config = 0;
+        }
+
+        set_attr.desc = 0;
+        clr_attr.desc = 0;
+
+        if (data)
+                set_attr.fields.tcp_csum_offload_ipv4 = 1;
+        else
+                clr_attr.fields.tcp_csum_offload_ipv4 = 1;
+
+        ret = h_illan_attributes(adapter->vdev->unit_address, 0, 0, &ret_attr.desc);
+
+        if (ret == H_SUCCESS && !ret_attr.fields.active_trunk &&
+            !ret_attr.fields.trunk_priority &&
+            ret_attr.fields.csum_offload_padded_pkt_support) {
+                ret = h_illan_attributes(adapter->vdev->unit_address, clr_attr.desc,
+                                         set_attr.desc, &ret_attr.desc);
+
+                if (ret != H_SUCCESS) {
+                        rc1 = -EIO;
+                        ibmveth_error_printk("unable to change checksum offload settings."
+                                             " %d rc=%ld\n", data, ret);
+
+                        ret = h_illan_attributes(adapter->vdev->unit_address,
+                                                 set_attr.desc, clr_attr.desc, &ret_attr.desc);
+                } else
+                        done(dev, data);
+        } else {
+                rc1 = -EIO;
+                ibmveth_error_printk("unable to change checksum offload settings."
+                                     " %d rc=%ld ret_attr=%lx\n", data, ret, ret_attr.desc);
+        }
+
+        if (restart)
+                rc2 = ibmveth_open(dev);
+
+        return rc1 ? rc1 : rc2;
+}
+
+static int ibmveth_set_rx_csum(struct net_device *dev, u32 data)
+{
+        struct ibmveth_adapter *adapter = dev->priv;
+
+        if ((data && adapter->rx_csum) || (!data && !adapter->rx_csum))
+                return 0;
+
+        return ibmveth_set_csum_offload(dev, data, ibmveth_set_rx_csum_flags);
+}
+
+static int ibmveth_set_tx_csum(struct net_device *dev, u32 data)
+{
+        struct ibmveth_adapter *adapter = dev->priv;
+        int rc = 0;
+
+        if (data && (dev->features & NETIF_F_IP_CSUM))
+                return 0;
+        if (!data && !(dev->features & NETIF_F_IP_CSUM))
+                return 0;
+
+        if (data && !adapter->rx_csum)
+                rc = ibmveth_set_csum_offload(dev, data, ibmveth_set_tx_csum_flags);
+        else
+                ibmveth_set_tx_csum_flags(dev, data);
+
+        return rc;
+}
+
+static u32 ibmveth_get_rx_csum(struct net_device *dev)
+{
+        struct ibmveth_adapter *adapter = dev->priv;
+        return adapter->rx_csum;
+}
+
 static const struct ethtool_ops netdev_ethtool_ops = {
         .get_drvinfo            = netdev_get_drvinfo,
         .get_settings           = netdev_get_settings,
         .get_link               = netdev_get_link,
         .get_sg                 = ethtool_op_get_sg,
         .get_tx_csum            = ethtool_op_get_tx_csum,
+        .set_tx_csum            = ibmveth_set_tx_csum,
+        .get_rx_csum            = ibmveth_get_rx_csum,
+        .set_rx_csum            = ibmveth_set_rx_csum,
 };
 
 static int ibmveth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
@@ -1103,9 +1223,10 @@ static int __devinit ibmveth_probe(struct vio_dev *dev, const struct vio_device_
                 ret = h_illan_attributes(dev->unit_address, 0, set_attr.desc,
                                          &ret_attr.desc);
 
-                if (ret == H_SUCCESS)
+                if (ret == H_SUCCESS) {
+                        adapter->rx_csum = 1;
                         netdev->features |= NETIF_F_IP_CSUM;
-                else
+                } else
                         ret = h_illan_attributes(dev->unit_address, set_attr.desc,
                                                  0, &ret_attr.desc);
         }
diff --git a/drivers/net/ibmveth.h b/drivers/net/ibmveth.h
index 3f10f0f4447a..43b068d9a558 100644
--- a/drivers/net/ibmveth.h
+++ b/drivers/net/ibmveth.h
@@ -138,6 +138,7 @@ struct ibmveth_adapter {
     struct ibmveth_buff_pool rx_buff_pool[IbmVethNumBufferPools];
     struct ibmveth_rx_q rx_queue;
     int pool_config;
+    int rx_csum;
 
     /* adapter specific stats */
     u64 replenish_task_cycles;