sdp: BUG1311 Netpipe fails with a IB_WC_LOC_LEN_ERR.

This problem is seen when the receive buffer or the receive buffer fragments
are smaller than the senders buffer. If the sender is using 64KB pages
and supports a sk fragment of 64KB it may send fragments that are a full 64KB
in length causing the receiver to generate an IB_WC_LOC_LEN_ERR. This patch
makes two changes:

If the kernel does not support a full 64KB fragment it will reject resize
requests over 32K. (On older kernels a fragment size is defined as a U16)

If a kernel supports a 64KB fragment then it allows a full 64KB receive
fragment to be used.

Signed-off-by: David Wilder <dwilder@us.ibm.com>
Signed-off-by: Amir Vadai <amirv@mellanox.co.il>

diff --git a/drivers/infiniband/ulp/sdp/sdp_bcopy.c b/drivers/infiniband/ulp/sdp/sdp_bcopy.c
index 1288c68e632dc6b39b7065cba61503e611cd5ea9..475d7c362991552076e82922f60695d68dc144f2 100644 (file)
--- a/drivers/infiniband/ulp/sdp/sdp_bcopy.c
+++ b/drivers/infiniband/ulp/sdp/sdp_bcopy.c
@@ -330,7 +330,13 @@ static void sdp_post_recv(struct sdp_sock *ssk)
                frag = &skb_shinfo(skb)->frags[i];
                frag->page                = page;
                frag->page_offset         = 0;
-               frag->size                =  min(PAGE_SIZE, SDP_MAX_PAYLOAD);
+
+               /* Bugzilla 1311 */
+               if ( sizeof(frag->size) < 4 )
+                       frag->size = min(PAGE_SIZE, SDP_MAX_PAYLOAD);
+               else
+                       frag->size = PAGE_SIZE;
+
                ++skb_shinfo(skb)->nr_frags;
                skb->len += frag->size;
                skb->data_len += frag->size;
@@ -607,17 +613,16 @@ int sdp_init_buffers(struct sdp_sock *ssk, u32 new_size)
 
 int sdp_resize_buffers(struct sdp_sock *ssk, u32 new_size)
 {
+       skb_frag_t skb_frag;
        u32 curr_size = SDP_HEAD_SIZE + ssk->recv_frags * PAGE_SIZE;
-#if defined(__ia64__)
-       /* for huge PAGE_SIZE systems, aka IA64, limit buffers size
-          [re-]negotiation to a known+working size that will not
-          trigger a HW error/rc to be interpreted as a IB_WC_LOC_LEN_ERR */
-       u32 max_size = (SDP_HEAD_SIZE + SDP_MAX_SEND_SKB_FRAGS * PAGE_SIZE) <=
-               32784 ?
-               (SDP_HEAD_SIZE + SDP_MAX_SEND_SKB_FRAGS * PAGE_SIZE): 32784;
-#else 
        u32 max_size = SDP_HEAD_SIZE + SDP_MAX_SEND_SKB_FRAGS * PAGE_SIZE;
-#endif
+
+       /* Bugzilla 1311, Kernels using smaller fragments must reject
+        * re-size requests larger than 32k to prevent being sent
+        * fragment larger than the receive buffer fragment.
+        */
+       if ( (sizeof(skb_frag.size) < 4) && (max_size > 0x8000))
+               max_size = 0x8000;
 
        if (new_size > curr_size && new_size <= max_size &&
            sdp_get_large_socket(ssk)) {