IB/mad: Add support for dual-sided RMPP transfers.
The implementation assumes that any RMPP request that requires a
response uses DS RMPP. Based on the RMPP start-up scenarios defined
by the spec, this should be a valid assumption. That is, there is no
start-up scenario defined where an RMPP request is followed by a
non-RMPP response. By having this assumption we avoid any API
changes.
In order for a node that supports DS RMPP to communicate with one that
does not, RMPP responses assume a new window size of 1 if a DS ACK has
not been received. (By DS ACK, I'm referring to the turn-around ACK
after the final ACK of the request.) This is a slight spec deviation,
but is necessary to allow communication with nodes that do not
generate the DS ACK. It also handles the case when a response is sent
after the request state has been discarded.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/core/mad_rmpp.c b/drivers/infiniband/core/mad_rmpp.c
index ebcd5b1..74fe1af 100644
--- a/drivers/infiniband/core/mad_rmpp.c
+++ b/drivers/infiniband/core/mad_rmpp.c
@@ -60,6 +60,7 @@
int last_ack;
int seg_num;
int newwin;
+ int repwin;
__be64 tid;
u32 src_qp;
@@ -170,6 +171,32 @@
return msg;
}
+static void ack_ds_ack(struct ib_mad_agent_private *agent,
+ struct ib_mad_recv_wc *recv_wc)
+{
+ struct ib_mad_send_buf *msg;
+ struct ib_rmpp_mad *rmpp_mad;
+ int ret;
+
+ msg = alloc_response_msg(&agent->agent, recv_wc);
+ if (IS_ERR(msg))
+ return;
+
+ rmpp_mad = msg->mad;
+ memcpy(rmpp_mad, recv_wc->recv_buf.mad, msg->hdr_len);
+
+ rmpp_mad->mad_hdr.method ^= IB_MGMT_METHOD_RESP;
+ ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);
+ rmpp_mad->rmpp_hdr.seg_num = 0;
+ rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(1);
+
+ ret = ib_post_send_mad(msg, NULL);
+ if (ret) {
+ ib_destroy_ah(msg->ah);
+ ib_free_send_mad(msg);
+ }
+}
+
void ib_rmpp_send_handler(struct ib_mad_send_wc *mad_send_wc)
{
struct ib_rmpp_mad *rmpp_mad = mad_send_wc->send_buf->mad;
@@ -271,6 +298,7 @@
rmpp_recv->newwin = 1;
rmpp_recv->seg_num = 1;
rmpp_recv->last_ack = 0;
+ rmpp_recv->repwin = 1;
mad_hdr = &mad_recv_wc->recv_buf.mad->mad_hdr;
rmpp_recv->tid = mad_hdr->tid;
@@ -591,6 +619,16 @@
break;
}
+static void process_ds_ack(struct ib_mad_agent_private *agent,
+ struct ib_mad_recv_wc *mad_recv_wc, int newwin)
+{
+ struct mad_rmpp_recv *rmpp_recv;
+
+ rmpp_recv = find_rmpp_recv(agent, mad_recv_wc);
+ if (rmpp_recv && rmpp_recv->state == RMPP_STATE_COMPLETE)
+ rmpp_recv->repwin = newwin;
+}
+
static void process_rmpp_ack(struct ib_mad_agent_private *agent,
struct ib_mad_recv_wc *mad_recv_wc)
{
@@ -616,8 +654,18 @@
spin_lock_irqsave(&agent->lock, flags);
mad_send_wr = ib_find_send_mad(agent, mad_recv_wc);
- if (!mad_send_wr)
- goto out; /* Unmatched ACK */
+ if (!mad_send_wr) {
+ if (!seg_num)
+ process_ds_ack(agent, mad_recv_wc, newwin);
+ goto out; /* Unmatched or DS RMPP ACK */
+ }
+
+ if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) &&
+ (mad_send_wr->timeout)) {
+ spin_unlock_irqrestore(&agent->lock, flags);
+ ack_ds_ack(agent, mad_recv_wc);
+ return; /* Repeated ACK for DS RMPP transaction */
+ }
if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) ||
(!mad_send_wr->timeout) || (mad_send_wr->status != IB_WC_SUCCESS))
@@ -656,6 +704,9 @@
if (mad_send_wr->refcount == 1)
ib_reset_mad_timeout(mad_send_wr,
mad_send_wr->send_buf.timeout_ms);
+ spin_unlock_irqrestore(&agent->lock, flags);
+ ack_ds_ack(agent, mad_recv_wc);
+ return;
} else if (mad_send_wr->refcount == 1 &&
mad_send_wr->seg_num < mad_send_wr->newwin &&
mad_send_wr->seg_num < mad_send_wr->send_buf.seg_count) {
@@ -772,6 +823,39 @@
return NULL;
}
+static int init_newwin(struct ib_mad_send_wr_private *mad_send_wr)
+{
+ struct ib_mad_agent_private *agent = mad_send_wr->mad_agent_priv;
+ struct ib_mad_hdr *mad_hdr = mad_send_wr->send_buf.mad;
+ struct mad_rmpp_recv *rmpp_recv;
+ struct ib_ah_attr ah_attr;
+ unsigned long flags;
+ int newwin = 1;
+
+ if (!(mad_hdr->method & IB_MGMT_METHOD_RESP))
+ goto out;
+
+ spin_lock_irqsave(&agent->lock, flags);
+ list_for_each_entry(rmpp_recv, &agent->rmpp_list, list) {
+ if (rmpp_recv->tid != mad_hdr->tid ||
+ rmpp_recv->mgmt_class != mad_hdr->mgmt_class ||
+ rmpp_recv->class_version != mad_hdr->class_version ||
+ (rmpp_recv->method & IB_MGMT_METHOD_RESP))
+ continue;
+
+ if (ib_query_ah(mad_send_wr->send_buf.ah, &ah_attr))
+ continue;
+
+ if (rmpp_recv->slid == ah_attr.dlid) {
+ newwin = rmpp_recv->repwin;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&agent->lock, flags);
+out:
+ return newwin;
+}
+
int ib_send_rmpp_mad(struct ib_mad_send_wr_private *mad_send_wr)
{
struct ib_rmpp_mad *rmpp_mad;
@@ -787,7 +871,7 @@
return IB_RMPP_RESULT_INTERNAL;
}
- mad_send_wr->newwin = 1;
+ mad_send_wr->newwin = init_newwin(mad_send_wr);
/* We need to wait for the final ACK even if there isn't a response */
mad_send_wr->refcount += (mad_send_wr->timeout == 0);
