[PATCH] IB/ipath: rC receive interrupt performance changes

This patch separates QP state used for sending and receiving RC packets so the
processing in the receive interrupt handler can be done mostly without locks
being held.  ACK packets are now sent without requiring synchronization with
the send tasklet.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Cc: "Michael S. Tsirkin" <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/infiniband/hw/ipath/ipath_keys.c

@@ -121,6 +121,7 @@ int ipath_lkey_ok(struct ipath_lkey_table *rkt, struct ipath_sge *isge,
 		  struct ib_sge *sge, int acc)
 {
 	struct ipath_mregion *mr;
+	unsigned n, m;
 	size_t off;
 	int ret;
 
@@ -152,20 +153,22 @@ int ipath_lkey_ok(struct ipath_lkey_table *rkt, struct ipath_sge *isge,
 	}
 
 	off += mr->offset;
-	isge->mr = mr;
-	isge->m = 0;
-	isge->n = 0;
-	while (off >= mr->map[isge->m]->segs[isge->n].length) {
-		off -= mr->map[isge->m]->segs[isge->n].length;
-		isge->n++;
-		if (isge->n >= IPATH_SEGSZ) {
-			isge->m++;
-			isge->n = 0;
+	m = 0;
+	n = 0;
+	while (off >= mr->map[m]->segs[n].length) {
+		off -= mr->map[m]->segs[n].length;
+		n++;
+		if (n >= IPATH_SEGSZ) {
+			m++;
+			n = 0;
 		}
 	}
-	isge->vaddr = mr->map[isge->m]->segs[isge->n].vaddr + off;
-	isge->length = mr->map[isge->m]->segs[isge->n].length - off;
+	isge->mr = mr;
+	isge->vaddr = mr->map[m]->segs[n].vaddr + off;
+	isge->length = mr->map[m]->segs[n].length - off;
 	isge->sge_length = sge->length;
+	isge->m = m;
+	isge->n = n;
 
 	ret = 1;
 
@@ -190,6 +193,7 @@ int ipath_rkey_ok(struct ipath_ibdev *dev, struct ipath_sge_state *ss,
 	struct ipath_lkey_table *rkt = &dev->lk_table;
 	struct ipath_sge *sge = &ss->sge;
 	struct ipath_mregion *mr;
+	unsigned n, m;
 	size_t off;
 	int ret;
 
@@ -207,20 +211,22 @@ int ipath_rkey_ok(struct ipath_ibdev *dev, struct ipath_sge_state *ss,
 	}
 
 	off += mr->offset;
-	sge->mr = mr;
-	sge->m = 0;
-	sge->n = 0;
-	while (off >= mr->map[sge->m]->segs[sge->n].length) {
-		off -= mr->map[sge->m]->segs[sge->n].length;
-		sge->n++;
-		if (sge->n >= IPATH_SEGSZ) {
-			sge->m++;
-			sge->n = 0;
+	m = 0;
+	n = 0;
+	while (off >= mr->map[m]->segs[n].length) {
+		off -= mr->map[m]->segs[n].length;
+		n++;
+		if (n >= IPATH_SEGSZ) {
+			m++;
+			n = 0;
 		}
 	}
-	sge->vaddr = mr->map[sge->m]->segs[sge->n].vaddr + off;
-	sge->length = mr->map[sge->m]->segs[sge->n].length - off;
+	sge->mr = mr;
+	sge->vaddr = mr->map[m]->segs[n].vaddr + off;
+	sge->length = mr->map[m]->segs[n].length - off;
 	sge->sge_length = len;
+	sge->m = m;
+	sge->n = n;
 	ss->sg_list = NULL;
 	ss->num_sge = 1;