IB/umad: Add support for large RMPP transfers

Add support for sending and receiving large RMPP transfers.  The old
code supports transfers only as large as a single contiguous kernel
memory allocation.  This patch uses linked list of memory buffers when
sending and receiving data to avoid needing contiguous pages for
larger transfers.

  Receive side: copy the arriving MADs in chunks instead of coalescing
  to one large buffer in kernel space.

  Send side: split a multipacket MAD buffer to a list of segments,
  (multipacket_list) and send these using a gather list of size 2.
  Also, save pointer to last sent segment, and retrieve requested
  segments by walking list starting at last sent segment. Finally,
  save pointer to last-acked segment.  When retrying, retrieve
  segments for resending relative to this pointer.  When updating last
  ack, start at this pointer.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

5 files changed, 376 insertions, 227 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 445ad0dda213..16549add8e8f 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -31,7 +31,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
- * $Id: mad.c 2817 2005-07-07 11:29:26Z halr $
+ * $Id: mad.c 5596 2006-03-03 01:00:07Z sean.hefty $
  */
 #include <linux/dma-mapping.h>
 
@@ -765,18 +765,67 @@ out:
         return ret;
 }
 
-static int get_buf_length(int hdr_len, int data_len)
+static int get_pad_size(int hdr_len, int data_len)
 {
         int seg_size, pad;
 
         seg_size = sizeof(struct ib_mad) - hdr_len;
         if (data_len && seg_size) {
                 pad = seg_size - data_len % seg_size;
-                if (pad == seg_size)
-                        pad = 0;
+                return pad == seg_size ? 0 : pad;
         } else
-                pad = seg_size;
-        return hdr_len + data_len + pad;
+                return seg_size;
+}
+
+static void free_send_rmpp_list(struct ib_mad_send_wr_private *mad_send_wr)
+{
+        struct ib_rmpp_segment *s, *t;
+
+        list_for_each_entry_safe(s, t, &mad_send_wr->rmpp_list, list) {
+                list_del(&s->list);
+                kfree(s);
+        }
+}
+
+static int alloc_send_rmpp_list(struct ib_mad_send_wr_private *send_wr,
+                                gfp_t gfp_mask)
+{
+        struct ib_mad_send_buf *send_buf = &send_wr->send_buf;
+        struct ib_rmpp_mad *rmpp_mad = send_buf->mad;
+        struct ib_rmpp_segment *seg = NULL;
+        int left, seg_size, pad;
+
+        send_buf->seg_size = sizeof (struct ib_mad) - send_buf->hdr_len;
+        seg_size = send_buf->seg_size;
+        pad = send_wr->pad;
+
+        /* Allocate data segments. */
+        for (left = send_buf->data_len + pad; left > 0; left -= seg_size) {
+                seg = kmalloc(sizeof (*seg) + seg_size, gfp_mask);
+                if (!seg) {
+                        printk(KERN_ERR "alloc_send_rmpp_segs: RMPP mem "
+                               "alloc failed for len %zd, gfp %#x\n",
+                               sizeof (*seg) + seg_size, gfp_mask);
+                        free_send_rmpp_list(send_wr);
+                        return -ENOMEM;
+                }
+                seg->num = ++send_buf->seg_count;
+                list_add_tail(&seg->list, &send_wr->rmpp_list);
+        }
+
+        /* Zero any padding */
+        if (pad)
+                memset(seg->data + seg_size - pad, 0, pad);
+
+        rmpp_mad->rmpp_hdr.rmpp_version = send_wr->mad_agent_priv->
+                                          agent.rmpp_version;
+        rmpp_mad->rmpp_hdr.rmpp_type = IB_MGMT_RMPP_TYPE_DATA;
+        ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);
+
+        send_wr->cur_seg = container_of(send_wr->rmpp_list.next,
+                                        struct ib_rmpp_segment, list);
+        send_wr->last_ack_seg = send_wr->cur_seg;
+        return 0;
 }
 
 struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
@@ -787,32 +836,40 @@ struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
 {
         struct ib_mad_agent_private *mad_agent_priv;
         struct ib_mad_send_wr_private *mad_send_wr;
-        int buf_size;
+        int pad, message_size, ret, size;
         void *buf;
 
         mad_agent_priv = container_of(mad_agent, struct ib_mad_agent_private,
                                       agent);
-        buf_size = get_buf_length(hdr_len, data_len);
+        pad = get_pad_size(hdr_len, data_len);
+        message_size = hdr_len + data_len + pad;
 
         if ((!mad_agent->rmpp_version &&
-             (rmpp_active || buf_size > sizeof(struct ib_mad))) ||
-            (!rmpp_active && buf_size > sizeof(struct ib_mad)))
+             (rmpp_active || message_size > sizeof(struct ib_mad))) ||
+            (!rmpp_active && message_size > sizeof(struct ib_mad)))
                 return ERR_PTR(-EINVAL);
 
-        buf = kzalloc(sizeof *mad_send_wr + buf_size, gfp_mask);
+        size = rmpp_active ? hdr_len : sizeof(struct ib_mad);
+        buf = kzalloc(sizeof *mad_send_wr + size, gfp_mask);
         if (!buf)
                 return ERR_PTR(-ENOMEM);
 
-        mad_send_wr = buf + buf_size;
+        mad_send_wr = buf + size;
+        INIT_LIST_HEAD(&mad_send_wr->rmpp_list);
         mad_send_wr->send_buf.mad = buf;
+        mad_send_wr->send_buf.hdr_len = hdr_len;
+        mad_send_wr->send_buf.data_len = data_len;
+        mad_send_wr->pad = pad;
 
         mad_send_wr->mad_agent_priv = mad_agent_priv;
-        mad_send_wr->sg_list[0].length = buf_size;
+        mad_send_wr->sg_list[0].length = hdr_len;
         mad_send_wr->sg_list[0].lkey = mad_agent->mr->lkey;
+        mad_send_wr->sg_list[1].length = sizeof(struct ib_mad) - hdr_len;
+        mad_send_wr->sg_list[1].lkey = mad_agent->mr->lkey;
 
         mad_send_wr->send_wr.wr_id = (unsigned long) mad_send_wr;
         mad_send_wr->send_wr.sg_list = mad_send_wr->sg_list;
-        mad_send_wr->send_wr.num_sge = 1;
+        mad_send_wr->send_wr.num_sge = 2;
         mad_send_wr->send_wr.opcode = IB_WR_SEND;
         mad_send_wr->send_wr.send_flags = IB_SEND_SIGNALED;
         mad_send_wr->send_wr.wr.ud.remote_qpn = remote_qpn;
@@ -820,13 +877,11 @@ struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
         mad_send_wr->send_wr.wr.ud.pkey_index = pkey_index;
 
         if (rmpp_active) {
-                struct ib_rmpp_mad *rmpp_mad = mad_send_wr->send_buf.mad;
-                rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(hdr_len -
-                                                   IB_MGMT_RMPP_HDR + data_len);
-                rmpp_mad->rmpp_hdr.rmpp_version = mad_agent->rmpp_version;
-                rmpp_mad->rmpp_hdr.rmpp_type = IB_MGMT_RMPP_TYPE_DATA;
-                ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr,
-                                  IB_MGMT_RMPP_FLAG_ACTIVE);
+                ret = alloc_send_rmpp_list(mad_send_wr, gfp_mask);
+                if (ret) {
+                        kfree(buf);
+                        return ERR_PTR(ret);
+                }
         }
 
         mad_send_wr->send_buf.mad_agent = mad_agent;
@@ -835,14 +890,50 @@ struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
 }
 EXPORT_SYMBOL(ib_create_send_mad);
 
+void *ib_get_rmpp_segment(struct ib_mad_send_buf *send_buf, int seg_num)
+{
+        struct ib_mad_send_wr_private *mad_send_wr;
+        struct list_head *list;
+
+        mad_send_wr = container_of(send_buf, struct ib_mad_send_wr_private,
+                                   send_buf);
+        list = &mad_send_wr->cur_seg->list;
+
+        if (mad_send_wr->cur_seg->num < seg_num) {
+                list_for_each_entry(mad_send_wr->cur_seg, list, list)
+                        if (mad_send_wr->cur_seg->num == seg_num)
+                                break;
+        } else if (mad_send_wr->cur_seg->num > seg_num) {
+                list_for_each_entry_reverse(mad_send_wr->cur_seg, list, list)
+                        if (mad_send_wr->cur_seg->num == seg_num)
+                                break;
+        }
+        return mad_send_wr->cur_seg->data;
+}
+EXPORT_SYMBOL(ib_get_rmpp_segment);
+
+static inline void *ib_get_payload(struct ib_mad_send_wr_private *mad_send_wr)
+{
+        if (mad_send_wr->send_buf.seg_count)
+                return ib_get_rmpp_segment(&mad_send_wr->send_buf,
+                                           mad_send_wr->seg_num);
+        else
+                return mad_send_wr->send_buf.mad +
+                       mad_send_wr->send_buf.hdr_len;
+}
+
 void ib_free_send_mad(struct ib_mad_send_buf *send_buf)
 {
         struct ib_mad_agent_private *mad_agent_priv;
+        struct ib_mad_send_wr_private *mad_send_wr;
 
         mad_agent_priv = container_of(send_buf->mad_agent,
                                       struct ib_mad_agent_private, agent);
-        kfree(send_buf->mad);
+        mad_send_wr = container_of(send_buf, struct ib_mad_send_wr_private,
+                                   send_buf);
 
+        free_send_rmpp_list(mad_send_wr);
+        kfree(send_buf->mad);
         if (atomic_dec_and_test(&mad_agent_priv->refcount))
                 wake_up(&mad_agent_priv->wait);
 }
@@ -865,10 +956,17 @@ int ib_send_mad(struct ib_mad_send_wr_private *mad_send_wr)
 
         mad_agent = mad_send_wr->send_buf.mad_agent;
         sge = mad_send_wr->sg_list;
-        sge->addr = dma_map_single(mad_agent->device->dma_device,
-                                   mad_send_wr->send_buf.mad, sge->length,
-                                   DMA_TO_DEVICE);
-        pci_unmap_addr_set(mad_send_wr, mapping, sge->addr);
+        sge[0].addr = dma_map_single(mad_agent->device->dma_device,
+                                     mad_send_wr->send_buf.mad,
+                                     sge[0].length,
+                                     DMA_TO_DEVICE);
+        pci_unmap_addr_set(mad_send_wr, header_mapping, sge[0].addr);
+
+        sge[1].addr = dma_map_single(mad_agent->device->dma_device,
+                                     ib_get_payload(mad_send_wr),
+                                     sge[1].length,
+                                     DMA_TO_DEVICE);
+        pci_unmap_addr_set(mad_send_wr, payload_mapping, sge[1].addr);
 
         spin_lock_irqsave(&qp_info->send_queue.lock, flags);
         if (qp_info->send_queue.count < qp_info->send_queue.max_active) {
@@ -885,11 +983,14 @@ int ib_send_mad(struct ib_mad_send_wr_private *mad_send_wr)
                 list_add_tail(&mad_send_wr->mad_list.list, list);
         }
         spin_unlock_irqrestore(&qp_info->send_queue.lock, flags);
-        if (ret)
+        if (ret) {
                 dma_unmap_single(mad_agent->device->dma_device,
-                                 pci_unmap_addr(mad_send_wr, mapping),
-                                 sge->length, DMA_TO_DEVICE);
-
+                                 pci_unmap_addr(mad_send_wr, header_mapping),
+                                 sge[0].length, DMA_TO_DEVICE);
+                dma_unmap_single(mad_agent->device->dma_device,
+                                 pci_unmap_addr(mad_send_wr, payload_mapping),
+                                 sge[1].length, DMA_TO_DEVICE);
+        }
         return ret;
 }
 
@@ -1860,8 +1961,11 @@ static void ib_mad_send_done_handler(struct ib_mad_port_private *port_priv,
 
 retry:
         dma_unmap_single(mad_send_wr->send_buf.mad_agent->device->dma_device,
-                         pci_unmap_addr(mad_send_wr, mapping),
+                         pci_unmap_addr(mad_send_wr, header_mapping),
                          mad_send_wr->sg_list[0].length, DMA_TO_DEVICE);
+        dma_unmap_single(mad_send_wr->send_buf.mad_agent->device->dma_device,
+                         pci_unmap_addr(mad_send_wr, payload_mapping),
+                         mad_send_wr->sg_list[1].length, DMA_TO_DEVICE);
         queued_send_wr = NULL;
         spin_lock_irqsave(&send_queue->lock, flags);
         list_del(&mad_list->list);
diff --git a/drivers/infiniband/core/mad_priv.h b/drivers/infiniband/core/mad_priv.h
index 570f78682af3..a7125d4b5ccf 100644
--- a/drivers/infiniband/core/mad_priv.h
+++ b/drivers/infiniband/core/mad_priv.h
@@ -31,7 +31,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
- * $Id: mad_priv.h 2730 2005-06-28 16:43:03Z sean.hefty $
+ * $Id: mad_priv.h 5596 2006-03-03 01:00:07Z sean.hefty $
  */
 
 #ifndef __IB_MAD_PRIV_H__
@@ -85,6 +85,12 @@ struct ib_mad_private {
         } mad;
 } __attribute__ ((packed));
 
+struct ib_rmpp_segment {
+        struct list_head list;
+        u32 num;
+        u8 data[0];
+};
+
 struct ib_mad_agent_private {
         struct list_head agent_list;
         struct ib_mad_agent agent;
@@ -119,7 +125,8 @@ struct ib_mad_send_wr_private {
         struct list_head agent_list;
         struct ib_mad_agent_private *mad_agent_priv;
         struct ib_mad_send_buf send_buf;
-        DECLARE_PCI_UNMAP_ADDR(mapping)
+        DECLARE_PCI_UNMAP_ADDR(header_mapping)
+        DECLARE_PCI_UNMAP_ADDR(payload_mapping)
         struct ib_send_wr send_wr;
         struct ib_sge sg_list[IB_MAD_SEND_REQ_MAX_SG];
         __be64 tid;
@@ -130,11 +137,12 @@ struct ib_mad_send_wr_private {
         enum ib_wc_status status;
 
         /* RMPP control */
+        struct list_head rmpp_list;
+        struct ib_rmpp_segment *last_ack_seg;
+        struct ib_rmpp_segment *cur_seg;
         int last_ack;
         int seg_num;
         int newwin;
-        int total_seg;
-        int data_offset;
         int pad;
 };
 
diff --git a/drivers/infiniband/core/mad_rmpp.c b/drivers/infiniband/core/mad_rmpp.c
index 3249e1d8c07b..bacfdd5bddad 100644
--- a/drivers/infiniband/core/mad_rmpp.c
+++ b/drivers/infiniband/core/mad_rmpp.c
@@ -111,14 +111,14 @@ static int data_offset(u8 mgmt_class)
                 return IB_MGMT_RMPP_HDR;
 }
 
-static void format_ack(struct ib_rmpp_mad *ack,
+static void format_ack(struct ib_mad_send_buf *msg,
                        struct ib_rmpp_mad *data,
                        struct mad_rmpp_recv *rmpp_recv)
 {
+        struct ib_rmpp_mad *ack = msg->mad;
         unsigned long flags;
 
-        memcpy(&ack->mad_hdr, &data->mad_hdr,
-               data_offset(data->mad_hdr.mgmt_class));
+        memcpy(ack, &data->mad_hdr, msg->hdr_len);
 
         ack->mad_hdr.method ^= IB_MGMT_METHOD_RESP;
         ack->rmpp_hdr.rmpp_type = IB_MGMT_RMPP_TYPE_ACK;
@@ -135,16 +135,16 @@ static void ack_recv(struct mad_rmpp_recv *rmpp_recv,
                      struct ib_mad_recv_wc *recv_wc)
 {
         struct ib_mad_send_buf *msg;
-        int ret;
+        int ret, hdr_len;
 
+        hdr_len = data_offset(recv_wc->recv_buf.mad->mad_hdr.mgmt_class);
         msg = ib_create_send_mad(&rmpp_recv->agent->agent, recv_wc->wc->src_qp,
-                                 recv_wc->wc->pkey_index, 1, IB_MGMT_RMPP_HDR,
-                                 IB_MGMT_RMPP_DATA, GFP_KERNEL);
+                                 recv_wc->wc->pkey_index, 1, hdr_len,
+                                 0, GFP_KERNEL);
         if (!msg)
                 return;
 
-        format_ack(msg->mad, (struct ib_rmpp_mad *) recv_wc->recv_buf.mad,
-                   rmpp_recv);
+        format_ack(msg, (struct ib_rmpp_mad *) recv_wc->recv_buf.mad, rmpp_recv);
         msg->ah = rmpp_recv->ah;
         ret = ib_post_send_mad(msg, NULL);
         if (ret)
@@ -156,16 +156,17 @@ static struct ib_mad_send_buf *alloc_response_msg(struct ib_mad_agent *agent,
 {
         struct ib_mad_send_buf *msg;
         struct ib_ah *ah;
+        int hdr_len;
 
         ah = ib_create_ah_from_wc(agent->qp->pd, recv_wc->wc,
                                   recv_wc->recv_buf.grh, agent->port_num);
         if (IS_ERR(ah))
                 return (void *) ah;
 
+        hdr_len = data_offset(recv_wc->recv_buf.mad->mad_hdr.mgmt_class);
         msg = ib_create_send_mad(agent, recv_wc->wc->src_qp,
                                  recv_wc->wc->pkey_index, 1,
-                                 IB_MGMT_RMPP_HDR, IB_MGMT_RMPP_DATA,
-                                 GFP_KERNEL);
+                                 hdr_len, 0, GFP_KERNEL);
         if (IS_ERR(msg))
                 ib_destroy_ah(ah);
         else
@@ -195,8 +196,7 @@ static void nack_recv(struct ib_mad_agent_private *agent,
                 return;
 
         rmpp_mad = msg->mad;
-        memcpy(rmpp_mad, recv_wc->recv_buf.mad,
-               data_offset(recv_wc->recv_buf.mad->mad_hdr.mgmt_class));
+        memcpy(rmpp_mad, recv_wc->recv_buf.mad, msg->hdr_len);
 
         rmpp_mad->mad_hdr.method ^= IB_MGMT_METHOD_RESP;
         rmpp_mad->rmpp_hdr.rmpp_version = IB_MGMT_RMPP_VERSION;
@@ -433,44 +433,6 @@ static struct ib_mad_recv_wc * complete_rmpp(struct mad_rmpp_recv *rmpp_recv)
         return rmpp_wc;
 }
 
-void ib_coalesce_recv_mad(struct ib_mad_recv_wc *mad_recv_wc, void *buf)
-{
-        struct ib_mad_recv_buf *seg_buf;
-        struct ib_rmpp_mad *rmpp_mad;
-        void *data;
-        int size, len, offset;
-        u8 flags;
-
-        len = mad_recv_wc->mad_len;
-        if (len <= sizeof(struct ib_mad)) {
-                memcpy(buf, mad_recv_wc->recv_buf.mad, len);
-                return;
-        }
-
-        offset = data_offset(mad_recv_wc->recv_buf.mad->mad_hdr.mgmt_class);
-
-        list_for_each_entry(seg_buf, &mad_recv_wc->rmpp_list, list) {
-                rmpp_mad = (struct ib_rmpp_mad *)seg_buf->mad;
-                flags = ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr);
-
-                if (flags & IB_MGMT_RMPP_FLAG_FIRST) {
-                        data = rmpp_mad;
-                        size = sizeof(*rmpp_mad);
-                } else {
-                        data = (void *) rmpp_mad + offset;
-                        if (flags & IB_MGMT_RMPP_FLAG_LAST)
-                                size = len;
-                        else
-                                size = sizeof(*rmpp_mad) - offset;
-                }
-
-                memcpy(buf, data, size);
-                len -= size;
-                buf += size;
-        }
-}
-EXPORT_SYMBOL(ib_coalesce_recv_mad);
-
 static struct ib_mad_recv_wc *
 continue_rmpp(struct ib_mad_agent_private *agent,
               struct ib_mad_recv_wc *mad_recv_wc)
@@ -570,50 +532,33 @@ start_rmpp(struct ib_mad_agent_private *agent,
         return mad_recv_wc;
 }
 
-static inline u64 get_seg_addr(struct ib_mad_send_wr_private *mad_send_wr)
-{
-        return mad_send_wr->sg_list[0].addr + mad_send_wr->data_offset +
-               (sizeof(struct ib_rmpp_mad) - mad_send_wr->data_offset) *
-               (mad_send_wr->seg_num - 1);
-}
-
 static int send_next_seg(struct ib_mad_send_wr_private *mad_send_wr)
 {
         struct ib_rmpp_mad *rmpp_mad;
         int timeout;
-        u32 paylen;
+        u32 paylen = 0;
 
         rmpp_mad = mad_send_wr->send_buf.mad;
         ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);
-        rmpp_mad->rmpp_hdr.seg_num = cpu_to_be32(mad_send_wr->seg_num);
+        rmpp_mad->rmpp_hdr.seg_num = cpu_to_be32(++mad_send_wr->seg_num);
 
         if (mad_send_wr->seg_num == 1) {
                 rmpp_mad->rmpp_hdr.rmpp_rtime_flags |= IB_MGMT_RMPP_FLAG_FIRST;
-                paylen = mad_send_wr->total_seg * IB_MGMT_RMPP_DATA -
+                paylen = mad_send_wr->send_buf.seg_count * IB_MGMT_RMPP_DATA -
                          mad_send_wr->pad;
-                rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(paylen);
-                mad_send_wr->sg_list[0].length = sizeof(struct ib_rmpp_mad);
-        } else {
-                mad_send_wr->send_wr.num_sge = 2;
-                mad_send_wr->sg_list[0].length = mad_send_wr->data_offset;
-                mad_send_wr->sg_list[1].addr = get_seg_addr(mad_send_wr);
-                mad_send_wr->sg_list[1].length = sizeof(struct ib_rmpp_mad) -
-                                                 mad_send_wr->data_offset;
-                mad_send_wr->sg_list[1].lkey = mad_send_wr->sg_list[0].lkey;
-                rmpp_mad->rmpp_hdr.paylen_newwin = 0;
         }
 
-        if (mad_send_wr->seg_num == mad_send_wr->total_seg) {
+        if (mad_send_wr->seg_num == mad_send_wr->send_buf.seg_count) {
                 rmpp_mad->rmpp_hdr.rmpp_rtime_flags |= IB_MGMT_RMPP_FLAG_LAST;
                 paylen = IB_MGMT_RMPP_DATA - mad_send_wr->pad;
-                rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(paylen);
         }
+        rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(paylen);
 
         /* 2 seconds for an ACK until we can find the packet lifetime */
         timeout = mad_send_wr->send_buf.timeout_ms;
         if (!timeout || timeout > 2000)
                 mad_send_wr->timeout = msecs_to_jiffies(2000);
-        mad_send_wr->seg_num++;
+
         return ib_send_mad(mad_send_wr);
 }
 
@@ -629,7 +574,7 @@ static void abort_send(struct ib_mad_agent_private *agent, __be64 tid,
         if (!mad_send_wr)
                 goto out;       /* Unmatched send */
 
-        if ((mad_send_wr->last_ack == mad_send_wr->total_seg) ||
+        if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) ||
             (!mad_send_wr->timeout) || (mad_send_wr->status != IB_WC_SUCCESS))
                 goto out;       /* Send is already done */
 
@@ -645,6 +590,18 @@ out:
         spin_unlock_irqrestore(&agent->lock, flags);
 }
 
+static inline void adjust_last_ack(struct ib_mad_send_wr_private *wr,
+                                   int seg_num)
+{
+        struct list_head *list;
+
+        wr->last_ack = seg_num;
+        list = &wr->last_ack_seg->list;
+        list_for_each_entry(wr->last_ack_seg, list, list)
+                if (wr->last_ack_seg->num == seg_num)
+                        break;
+}
+
 static void process_rmpp_ack(struct ib_mad_agent_private *agent,
                              struct ib_mad_recv_wc *mad_recv_wc)
 {
@@ -675,11 +632,12 @@ static void process_rmpp_ack(struct ib_mad_agent_private *agent,
         if (!mad_send_wr)
                 goto out;       /* Unmatched ACK */
 
-        if ((mad_send_wr->last_ack == mad_send_wr->total_seg) ||
+        if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) ||
             (!mad_send_wr->timeout) || (mad_send_wr->status != IB_WC_SUCCESS))
                 goto out;       /* Send is already done */
 
-        if (seg_num > mad_send_wr->total_seg || seg_num > mad_send_wr->newwin) {
+        if (seg_num > mad_send_wr->send_buf.seg_count ||
+            seg_num > mad_send_wr->newwin) {
                 spin_unlock_irqrestore(&agent->lock, flags);
                 abort_send(agent, rmpp_mad->mad_hdr.tid,
                            IB_MGMT_RMPP_STATUS_S2B);
@@ -691,11 +649,11 @@ static void process_rmpp_ack(struct ib_mad_agent_private *agent,
                 goto out;       /* Old ACK */
 
         if (seg_num > mad_send_wr->last_ack) {
-                mad_send_wr->last_ack = seg_num;
+                adjust_last_ack(mad_send_wr, seg_num);
                 mad_send_wr->retries = mad_send_wr->send_buf.retries;
         }
         mad_send_wr->newwin = newwin;
-        if (mad_send_wr->last_ack == mad_send_wr->total_seg) {
+        if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) {
                 /* If no response is expected, the ACK completes the send */
                 if (!mad_send_wr->send_buf.timeout_ms) {
                         struct ib_mad_send_wc wc;
@@ -714,7 +672,7 @@ static void process_rmpp_ack(struct ib_mad_agent_private *agent,
                                              mad_send_wr->send_buf.timeout_ms);
         } else if (mad_send_wr->refcount == 1 &&
                    mad_send_wr->seg_num < mad_send_wr->newwin &&
-                   mad_send_wr->seg_num <= mad_send_wr->total_seg) {
+                   mad_send_wr->seg_num < mad_send_wr->send_buf.seg_count) {
                 /* Send failure will just result in a timeout/retry */
                 ret = send_next_seg(mad_send_wr);
                 if (ret)
@@ -838,31 +796,19 @@ out:
 int ib_send_rmpp_mad(struct ib_mad_send_wr_private *mad_send_wr)
 {
         struct ib_rmpp_mad *rmpp_mad;
-        int i, total_len, ret;
+        int ret;
 
         rmpp_mad = mad_send_wr->send_buf.mad;
         if (!(ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
               IB_MGMT_RMPP_FLAG_ACTIVE))
                 return IB_RMPP_RESULT_UNHANDLED;
 
-        if (rmpp_mad->rmpp_hdr.rmpp_type != IB_MGMT_RMPP_TYPE_DATA)
+        if (rmpp_mad->rmpp_hdr.rmpp_type != IB_MGMT_RMPP_TYPE_DATA) {
+                mad_send_wr->seg_num = 1;
                 return IB_RMPP_RESULT_INTERNAL;
+        }
 
-        if (mad_send_wr->send_wr.num_sge > 1)
-                return -EINVAL;         /* TODO: support num_sge > 1 */
-
-        mad_send_wr->seg_num = 1;
         mad_send_wr->newwin = 1;
-        mad_send_wr->data_offset = data_offset(rmpp_mad->mad_hdr.mgmt_class);
-
-        total_len = 0;
-        for (i = 0; i < mad_send_wr->send_wr.num_sge; i++)
-                total_len += mad_send_wr->send_wr.sg_list[i].length;
-
-        mad_send_wr->total_seg = (total_len - mad_send_wr->data_offset) /
-                        (sizeof(struct ib_rmpp_mad) - mad_send_wr->data_offset);
-        mad_send_wr->pad = total_len - IB_MGMT_RMPP_HDR -
-                           be32_to_cpu(rmpp_mad->rmpp_hdr.paylen_newwin);
 
         /* We need to wait for the final ACK even if there isn't a response */
         mad_send_wr->refcount += (mad_send_wr->timeout == 0);
@@ -893,14 +839,14 @@ int ib_process_rmpp_send_wc(struct ib_mad_send_wr_private *mad_send_wr,
         if (!mad_send_wr->timeout)
                 return IB_RMPP_RESULT_PROCESSED; /* Response received */
 
-        if (mad_send_wr->last_ack == mad_send_wr->total_seg) {
+        if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) {
                 mad_send_wr->timeout =
                         msecs_to_jiffies(mad_send_wr->send_buf.timeout_ms);
                 return IB_RMPP_RESULT_PROCESSED; /* Send done */
         }
 
-        if (mad_send_wr->seg_num > mad_send_wr->newwin ||
-            mad_send_wr->seg_num > mad_send_wr->total_seg)
+        if (mad_send_wr->seg_num == mad_send_wr->newwin ||
+            mad_send_wr->seg_num == mad_send_wr->send_buf.seg_count)
                 return IB_RMPP_RESULT_PROCESSED; /* Wait for ACK */
 
         ret = send_next_seg(mad_send_wr);
@@ -921,10 +867,12 @@ int ib_retry_rmpp(struct ib_mad_send_wr_private *mad_send_wr)
               IB_MGMT_RMPP_FLAG_ACTIVE))
                 return IB_RMPP_RESULT_UNHANDLED; /* RMPP not active */
 
-        if (mad_send_wr->last_ack == mad_send_wr->total_seg)
+        if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count)
                 return IB_RMPP_RESULT_PROCESSED;
 
-        mad_send_wr->seg_num = mad_send_wr->last_ack + 1;
+        mad_send_wr->seg_num = mad_send_wr->last_ack;
+        mad_send_wr->cur_seg = mad_send_wr->last_ack_seg;
+
         ret = send_next_seg(mad_send_wr);
         if (ret)
                 return IB_RMPP_RESULT_PROCESSED;
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index c908de8db5a9..fb6cd42601f9 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -31,7 +31,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
- * $Id: user_mad.c 4010 2005-11-09 23:11:56Z roland $
+ * $Id: user_mad.c 5596 2006-03-03 01:00:07Z sean.hefty $
  */
 
 #include <linux/module.h>
@@ -121,6 +121,7 @@ struct ib_umad_file {
 
 struct ib_umad_packet {
         struct ib_mad_send_buf *msg;
+        struct ib_mad_recv_wc  *recv_wc;
         struct list_head   list;
         int                length;
         struct ib_user_mad mad;
@@ -176,31 +177,32 @@ static int queue_packet(struct ib_umad_file *file,
         return ret;
 }
 
+static int data_offset(u8 mgmt_class)
+{
+        if (mgmt_class == IB_MGMT_CLASS_SUBN_ADM)
+                return IB_MGMT_SA_HDR;
+        else if ((mgmt_class >= IB_MGMT_CLASS_VENDOR_RANGE2_START) &&
+                 (mgmt_class <= IB_MGMT_CLASS_VENDOR_RANGE2_END))
+                return IB_MGMT_VENDOR_HDR;
+        else
+                return IB_MGMT_RMPP_HDR;
+}
+
 static void send_handler(struct ib_mad_agent *agent,
                          struct ib_mad_send_wc *send_wc)
 {
         struct ib_umad_file *file = agent->context;
-        struct ib_umad_packet *timeout;
         struct ib_umad_packet *packet = send_wc->send_buf->context[0];
 
         ib_destroy_ah(packet->msg->ah);
         ib_free_send_mad(packet->msg);
 
         if (send_wc->status == IB_WC_RESP_TIMEOUT_ERR) {
-                timeout = kzalloc(sizeof *timeout + IB_MGMT_MAD_HDR, GFP_KERNEL);
-                if (!timeout)
-                        goto out;
-
-                timeout->length         = IB_MGMT_MAD_HDR;
-                timeout->mad.hdr.id     = packet->mad.hdr.id;
-                timeout->mad.hdr.status = ETIMEDOUT;
-                memcpy(timeout->mad.data, packet->mad.data,
-                       sizeof (struct ib_mad_hdr));
-
-                if (queue_packet(file, agent, timeout))
-                        kfree(timeout);
+                packet->length = IB_MGMT_MAD_HDR;
+                packet->mad.hdr.status = ETIMEDOUT;
+                if (!queue_packet(file, agent, packet))
+                        return;
         }
-out:
         kfree(packet);
 }
 
@@ -209,22 +211,20 @@ static void recv_handler(struct ib_mad_agent *agent,
 {
         struct ib_umad_file *file = agent->context;
         struct ib_umad_packet *packet;
-        int length;
 
         if (mad_recv_wc->wc->status != IB_WC_SUCCESS)
-                goto out;
+                goto err1;
 
-        length = mad_recv_wc->mad_len;
-        packet = kzalloc(sizeof *packet + length, GFP_KERNEL);
+        packet = kzalloc(sizeof *packet, GFP_KERNEL);
         if (!packet)
-                goto out;
+                goto err1;
 
-        packet->length = length;
-
-        ib_coalesce_recv_mad(mad_recv_wc, packet->mad.data);
+        packet->length = mad_recv_wc->mad_len;
+        packet->recv_wc = mad_recv_wc;
 
         packet->mad.hdr.status    = 0;
-        packet->mad.hdr.length    = length + sizeof (struct ib_user_mad);
+        packet->mad.hdr.length    = sizeof (struct ib_user_mad) +
+                                    mad_recv_wc->mad_len;
         packet->mad.hdr.qpn       = cpu_to_be32(mad_recv_wc->wc->src_qp);
         packet->mad.hdr.lid       = cpu_to_be16(mad_recv_wc->wc->slid);
         packet->mad.hdr.sl        = mad_recv_wc->wc->sl;
@@ -240,12 +240,79 @@ static void recv_handler(struct ib_mad_agent *agent,
         }
 
         if (queue_packet(file, agent, packet))
-                kfree(packet);
+                goto err2;
+        return;
 
-out:
+err2:
+        kfree(packet);
+err1:
         ib_free_recv_mad(mad_recv_wc);
 }
 
+static ssize_t copy_recv_mad(char __user *buf, struct ib_umad_packet *packet,
+                             size_t count)
+{
+        struct ib_mad_recv_buf *recv_buf;
+        int left, seg_payload, offset, max_seg_payload;
+
+        /* We need enough room to copy the first (or only) MAD segment. */
+        recv_buf = &packet->recv_wc->recv_buf;
+        if ((packet->length <= sizeof (*recv_buf->mad) &&
+             count < sizeof (packet->mad) + packet->length) ||
+            (packet->length > sizeof (*recv_buf->mad) &&
+             count < sizeof (packet->mad) + sizeof (*recv_buf->mad)))
+                return -EINVAL;
+
+        if (copy_to_user(buf, &packet->mad, sizeof (packet->mad)))
+                return -EFAULT;
+
+        buf += sizeof (packet->mad);
+        seg_payload = min_t(int, packet->length, sizeof (*recv_buf->mad));
+        if (copy_to_user(buf, recv_buf->mad, seg_payload))
+                return -EFAULT;
+
+        if (seg_payload < packet->length) {
+                /*
+                 * Multipacket RMPP MAD message. Copy remainder of message.
+                 * Note that last segment may have a shorter payload.
+                 */
+                if (count < sizeof (packet->mad) + packet->length) {
+                        /*
+                         * The buffer is too small, return the first RMPP segment,
+                         * which includes the RMPP message length.
+                         */
+                        return -ENOSPC;
+                }
+                offset = data_offset(recv_buf->mad->mad_hdr.mgmt_class);
+                max_seg_payload = sizeof (struct ib_mad) - offset;
+
+                for (left = packet->length - seg_payload, buf += seg_payload;
+                     left; left -= seg_payload, buf += seg_payload) {
+                        recv_buf = container_of(recv_buf->list.next,
+                                                struct ib_mad_recv_buf, list);
+                        seg_payload = min(left, max_seg_payload);
+                        if (copy_to_user(buf, ((void *) recv_buf->mad) + offset,
+                                         seg_payload))
+                                return -EFAULT;
+                }
+        }
+        return sizeof (packet->mad) + packet->length;
+}
+
+static ssize_t copy_send_mad(char __user *buf, struct ib_umad_packet *packet,
+                             size_t count)
+{
+        ssize_t size = sizeof (packet->mad) + packet->length;
+
+        if (count < size)
+                return -EINVAL;
+
+        if (copy_to_user(buf, &packet->mad, size))
+                return -EFAULT;
+
+        return size;
+}
+
 static ssize_t ib_umad_read(struct file *filp, char __user *buf,
                             size_t count, loff_t *pos)
 {
@@ -253,7 +320,7 @@ static ssize_t ib_umad_read(struct file *filp, char __user *buf,
         struct ib_umad_packet *packet;
         ssize_t ret;
 
-        if (count < sizeof (struct ib_user_mad) + sizeof (struct ib_mad))
+        if (count < sizeof (struct ib_user_mad))
                 return -EINVAL;
 
         spin_lock_irq(&file->recv_lock);
@@ -276,28 +343,44 @@ static ssize_t ib_umad_read(struct file *filp, char __user *buf,
 
         spin_unlock_irq(&file->recv_lock);
 
-        if (count < packet->length + sizeof (struct ib_user_mad)) {
-                /* Return length needed (and first RMPP segment) if too small */
-                if (copy_to_user(buf, &packet->mad,
-                                 sizeof (struct ib_user_mad) + sizeof (struct ib_mad)))
-                        ret = -EFAULT;
-                else
-                        ret = -ENOSPC;
-        } else if (copy_to_user(buf, &packet->mad,
-                                packet->length + sizeof (struct ib_user_mad)))
-                ret = -EFAULT;
+        if (packet->recv_wc)
+                ret = copy_recv_mad(buf, packet, count);
         else
-                ret = packet->length + sizeof (struct ib_user_mad);
+                ret = copy_send_mad(buf, packet, count);
+
         if (ret < 0) {
                 /* Requeue packet */
                 spin_lock_irq(&file->recv_lock);
                 list_add(&packet->list, &file->recv_list);
                 spin_unlock_irq(&file->recv_lock);
-        } else
+        } else {
+                if (packet->recv_wc)
+                        ib_free_recv_mad(packet->recv_wc);
                 kfree(packet);
+        }
         return ret;
 }
 
+static int copy_rmpp_mad(struct ib_mad_send_buf *msg, const char __user *buf)
+{
+        int left, seg;
+
+        /* Copy class specific header */
+        if ((msg->hdr_len > IB_MGMT_RMPP_HDR) &&
+            copy_from_user(msg->mad + IB_MGMT_RMPP_HDR, buf + IB_MGMT_RMPP_HDR,
+                           msg->hdr_len - IB_MGMT_RMPP_HDR))
+                return -EFAULT;
+
+        /* All headers are in place.  Copy data segments. */
+        for (seg = 1, left = msg->data_len, buf += msg->hdr_len; left > 0;
+             seg++, left -= msg->seg_size, buf += msg->seg_size) {
+                if (copy_from_user(ib_get_rmpp_segment(msg, seg), buf,
+                                   min(left, msg->seg_size)))
+                        return -EFAULT;
+        }
+        return 0;
+}
+
 static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
                              size_t count, loff_t *pos)
 {
@@ -309,14 +392,12 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
         struct ib_rmpp_mad *rmpp_mad;
         u8 method;
         __be64 *tid;
-        int ret, length, hdr_len, copy_offset;
-        int rmpp_active, has_rmpp_header;
+        int ret, data_len, hdr_len, copy_offset, rmpp_active;
 
         if (count < sizeof (struct ib_user_mad) + IB_MGMT_RMPP_HDR)
                 return -EINVAL;
 
-        length = count - sizeof (struct ib_user_mad);
-        packet = kmalloc(sizeof *packet + IB_MGMT_RMPP_HDR, GFP_KERNEL);
+        packet = kzalloc(sizeof *packet + IB_MGMT_RMPP_HDR, GFP_KERNEL);
         if (!packet)
                 return -ENOMEM;
 
@@ -363,35 +444,25 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
         if (rmpp_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_ADM) {
                 hdr_len = IB_MGMT_SA_HDR;
                 copy_offset = IB_MGMT_RMPP_HDR;
-                has_rmpp_header = 1;
+                rmpp_active = ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
+                              IB_MGMT_RMPP_FLAG_ACTIVE;
         } else if (rmpp_mad->mad_hdr.mgmt_class >= IB_MGMT_CLASS_VENDOR_RANGE2_START &&
                    rmpp_mad->mad_hdr.mgmt_class <= IB_MGMT_CLASS_VENDOR_RANGE2_END) {
-                        hdr_len = IB_MGMT_VENDOR_HDR;
-                        copy_offset = IB_MGMT_RMPP_HDR;
-                        has_rmpp_header = 1;
+                hdr_len = IB_MGMT_VENDOR_HDR;
+                copy_offset = IB_MGMT_RMPP_HDR;
+                rmpp_active = ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
+                              IB_MGMT_RMPP_FLAG_ACTIVE;
         } else {
                 hdr_len = IB_MGMT_MAD_HDR;
                 copy_offset = IB_MGMT_MAD_HDR;
-                has_rmpp_header = 0;
-        }
-
-        if (has_rmpp_header)
-                rmpp_active = ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
-                              IB_MGMT_RMPP_FLAG_ACTIVE;
-        else
                 rmpp_active = 0;
-
-        /* Validate that the management class can support RMPP */
-        if (rmpp_active && !agent->rmpp_version) {
-                ret = -EINVAL;
-                goto err_ah;
         }
 
+        data_len = count - sizeof (struct ib_user_mad) - hdr_len;
         packet->msg = ib_create_send_mad(agent,
                                          be32_to_cpu(packet->mad.hdr.qpn),
-                                         0, rmpp_active,
-                                         hdr_len, length - hdr_len,
-                                         GFP_KERNEL);
+                                         0, rmpp_active, hdr_len,
+                                         data_len, GFP_KERNEL);
         if (IS_ERR(packet->msg)) {
                 ret = PTR_ERR(packet->msg);
                 goto err_ah;
@@ -402,14 +473,21 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
         packet->msg->retries    = packet->mad.hdr.retries;
         packet->msg->context[0] = packet;
 
-        /* Copy MAD headers (RMPP header in place) */
+        /* Copy MAD header.  Any RMPP header is already in place. */
         memcpy(packet->msg->mad, packet->mad.data, IB_MGMT_MAD_HDR);
-        /* Now, copy rest of message from user into send buffer */
-        if (copy_from_user(packet->msg->mad + copy_offset,
-                           buf + sizeof (struct ib_user_mad) + copy_offset,
-                           length - copy_offset)) {
-                ret = -EFAULT;
-                goto err_msg;
+        buf += sizeof (struct ib_user_mad);
+
+        if (!rmpp_active) {
+                if (copy_from_user(packet->msg->mad + copy_offset,
+                                   buf + copy_offset,
+                                   hdr_len + data_len - copy_offset)) {
+                        ret = -EFAULT;
+                        goto err_msg;
+                }
+        } else {
+                ret = copy_rmpp_mad(packet->msg, buf);
+                if (ret)
+                        goto err_msg;
         }
 
         /*
@@ -433,18 +511,14 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
                 goto err_msg;
 
         up_read(&file->port->mutex);
-
         return count;
 
 err_msg:
         ib_free_send_mad(packet->msg);
-
 err_ah:
         ib_destroy_ah(ah);
-
 err_up:
         up_read(&file->port->mutex);
-
 err:
         kfree(packet);
         return ret;
@@ -627,8 +701,11 @@ static int ib_umad_close(struct inode *inode, struct file *filp)
         already_dead = file->agents_dead;
         file->agents_dead = 1;
 
-        list_for_each_entry_safe(packet, tmp, &file->recv_list, list)
+        list_for_each_entry_safe(packet, tmp, &file->recv_list, list) {
+                if (packet->recv_wc)
+                        ib_free_recv_mad(packet->recv_wc);
                 kfree(packet);
+        }
 
         list_del(&file->port_list);
 
diff --git a/include/rdma/ib_mad.h b/include/rdma/ib_mad.h
index 2c133506742b..51ab8eddb295 100644
--- a/include/rdma/ib_mad.h
+++ b/include/rdma/ib_mad.h
@@ -33,7 +33,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
- * $Id: ib_mad.h 2775 2005-07-02 13:42:12Z halr $
+ * $Id: ib_mad.h 5596 2006-03-03 01:00:07Z sean.hefty $
  */
 
 #if !defined( IB_MAD_H )
@@ -208,15 +208,23 @@ struct ib_class_port_info
 /**
  * ib_mad_send_buf - MAD data buffer and work request for sends.
  * @next: A pointer used to chain together MADs for posting.
- * @mad: References an allocated MAD data buffer.
+ * @mad: References an allocated MAD data buffer for MADs that do not have
+ *   RMPP active.  For MADs using RMPP, references the common and management
+ *   class specific headers.
  * @mad_agent: MAD agent that allocated the buffer.
  * @ah: The address handle to use when sending the MAD.
  * @context: User-controlled context fields.
+ * @hdr_len: Indicates the size of the data header of the MAD.  This length
+ *   includes the common MAD, RMPP, and class specific headers.
+ * @data_len: Indicates the total size of user-transferred data.
+ * @seg_count: The number of RMPP segments allocated for this send.
+ * @seg_size: Size of each RMPP segment.
  * @timeout_ms: Time to wait for a response.
  * @retries: Number of times to retry a request for a response.
  *
  * Users are responsible for initializing the MAD buffer itself, with the
- * exception of specifying the payload length field in any RMPP MAD.
+ * exception of any RMPP header.  Additional segment buffer space allocated
+ * beyond data_len is padding.
  */
 struct ib_mad_send_buf {
         struct ib_mad_send_buf  *next;
@@ -224,6 +232,10 @@ struct ib_mad_send_buf {
         struct ib_mad_agent     *mad_agent;
         struct ib_ah            *ah;
         void                    *context[2];
+        int                     hdr_len;
+        int                     data_len;
+        int                     seg_count;
+        int                     seg_size;
         int                     timeout_ms;
         int                     retries;
 };
@@ -299,7 +311,7 @@ typedef void (*ib_mad_snoop_handler)(struct ib_mad_agent *mad_agent,
  * @mad_recv_wc: Received work completion information on the received MAD.
  *
  * MADs received in response to a send request operation will be handed to
- * the user after the send operation completes.  All data buffers given
+ * the user before the send operation completes.  All data buffers given
  * to registered agents through this routine are owned by the receiving
  * client, except for snooping agents.  Clients snooping MADs should not
  * modify the data referenced by @mad_recv_wc.
@@ -485,17 +497,6 @@ int ib_unregister_mad_agent(struct ib_mad_agent *mad_agent);
 int ib_post_send_mad(struct ib_mad_send_buf *send_buf,
                      struct ib_mad_send_buf **bad_send_buf);
 
-/**
- * ib_coalesce_recv_mad - Coalesces received MAD data into a single buffer.
- * @mad_recv_wc: Work completion information for a received MAD.
- * @buf: User-provided data buffer to receive the coalesced buffers.  The
- *   referenced buffer should be at least the size of the mad_len specified
- *   by @mad_recv_wc.
- *
- * This call copies a chain of received MAD segments into a single data buffer,
- * removing duplicated headers.
- */
-void ib_coalesce_recv_mad(struct ib_mad_recv_wc *mad_recv_wc, void *buf);
 
 /**
  * ib_free_recv_mad - Returns data buffers used to receive a MAD.
@@ -590,9 +591,10 @@ int ib_process_mad_wc(struct ib_mad_agent *mad_agent,
  * with an initialized work request structure.  Users may modify the returned
  * MAD data buffer before posting the send.
  *
- * The returned data buffer will be cleared.  Users are responsible for
- * initializing the common MAD and any class specific headers.  If @rmpp_active
- * is set, the RMPP header will be initialized for sending.
+ * The returned MAD header, class specific headers, and any padding will be
+ * cleared.  Users are responsible for initializing the common MAD header,
+ * any class specific header, and MAD data area.
+ * If @rmpp_active is set, the RMPP header will be initialized for sending.
  */
 struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
                                             u32 remote_qpn, u16 pkey_index,
@@ -601,6 +603,16 @@ struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
                                             gfp_t gfp_mask);
 
 /**
+ * ib_get_rmpp_segment - returns the data buffer for a given RMPP segment.
+ * @send_buf: Previously allocated send data buffer.
+ * @seg_num: number of segment to return
+ *
+ * This routine returns a pointer to the data buffer of an RMPP MAD.
+ * Users must provide synchronization to @send_buf around this call.
+ */
+void *ib_get_rmpp_segment(struct ib_mad_send_buf *send_buf, int seg_num);
+
+/**
  * ib_free_send_mad - Returns data buffers used to send a MAD.
  * @send_buf: Previously allocated send data buffer.
  */