sky2: Factor out code to calculate packet sizes

Move code to calculate receive threshold and packet size out of
sky2_rx_start() so that is can be called from elsewhere easily.

Signed-off-by: Mike McCormack <mikem@ring3k.org>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 37 insertions, 20 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 8a87e16e732f..c5de65c6f6e1 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1049,6 +1049,40 @@ static inline struct sky2_rx_le *sky2_next_rx(struct sky2_port *sky2)
         return le;
 }
 
+static unsigned sky2_get_rx_threshold(struct sky2_port* sky2)
+{
+        unsigned size;
+
+        /* Space needed for frame data + headers rounded up */
+        size = roundup(sky2->netdev->mtu + ETH_HLEN + VLAN_HLEN, 8);
+
+        /* Stopping point for hardware truncation */
+        return (size - 8) / sizeof(u32);
+}
+
+static unsigned sky2_get_rx_data_size(struct sky2_port* sky2)
+{
+        struct rx_ring_info *re;
+        unsigned size;
+
+        /* Space needed for frame data + headers rounded up */
+        size = roundup(sky2->netdev->mtu + ETH_HLEN + VLAN_HLEN, 8);
+
+        sky2->rx_nfrags = size >> PAGE_SHIFT;
+        BUG_ON(sky2->rx_nfrags > ARRAY_SIZE(re->frag_addr));
+
+        /* Compute residue after pages */
+        size -= sky2->rx_nfrags << PAGE_SHIFT;
+
+        /* Optimize to handle small packets and headers */
+        if (size < copybreak)
+                size = copybreak;
+        if (size < ETH_HLEN)
+                size = ETH_HLEN;
+
+        return size;
+}
+
 /* Build description to hardware for one receive segment */
 static void sky2_rx_add(struct sky2_port *sky2,  u8 op,
                         dma_addr_t map, unsigned len)
@@ -1343,7 +1377,7 @@ static int sky2_rx_start(struct sky2_port *sky2)
         struct sky2_hw *hw = sky2->hw;
         struct rx_ring_info *re;
         unsigned rxq = rxqaddr[sky2->port];
-        unsigned i, size, thresh;
+        unsigned i, thresh;
 
         sky2->rx_put = sky2->rx_next = 0;
         sky2_qset(hw, rxq);
@@ -1364,25 +1398,7 @@ static int sky2_rx_start(struct sky2_port *sky2)
         if (!(hw->flags & SKY2_HW_NEW_LE))
                 rx_set_checksum(sky2);
 
-        /* Space needed for frame data + headers rounded up */
-        size = roundup(sky2->netdev->mtu + ETH_HLEN + VLAN_HLEN, 8);
-
-        /* Stopping point for hardware truncation */
-        thresh = (size - 8) / sizeof(u32);
-
-        sky2->rx_nfrags = size >> PAGE_SHIFT;
-        BUG_ON(sky2->rx_nfrags > ARRAY_SIZE(re->frag_addr));
-
-        /* Compute residue after pages */
-        size -= sky2->rx_nfrags << PAGE_SHIFT;
-
-        /* Optimize to handle small packets and headers */
-        if (size < copybreak)
-                size = copybreak;
-        if (size < ETH_HLEN)
-                size = ETH_HLEN;
-
-        sky2->rx_data_size = size;
+        sky2->rx_data_size = sky2_get_rx_data_size(sky2);
 
         /* Fill Rx ring */
         for (i = 0; i < sky2->rx_pending; i++) {
@@ -1407,6 +1423,7 @@ static int sky2_rx_start(struct sky2_port *sky2)
          * the register is limited to 9 bits, so if you do frames > 2052
          * you better get the MTU right!
          */
+        thresh = sky2_get_rx_threshold(sky2);
         if (thresh > 0x1ff)
                 sky2_write32(hw, SK_REG(sky2->port, RX_GMF_CTRL_T), RX_TRUNC_OFF);
         else {