IB/ipath: Don't allow QPs 0 and 1 to be opened multiple times

Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/hw/ipath/ipath_qp.c b/drivers/infiniband/hw/ipath/ipath_qp.c
index f671fd0..16db9ac 100644 (file)
--- a/drivers/infiniband/hw/ipath/ipath_qp.c
+++ b/drivers/infiniband/hw/ipath/ipath_qp.c
@@ -81,11 +81,51 @@ static u32 credit_table[31] = {
        32768                   /* 1E */
 };
 
-static u32 alloc_qpn(struct ipath_qp_table *qpt)
+
+static void get_map_page(struct ipath_qp_table *qpt, struct qpn_map *map)
+{
+       unsigned long page = get_zeroed_page(GFP_KERNEL);
+       unsigned long flags;
+
+       /*
+        * Free the page if someone raced with us installing it.
+        */
+
+       spin_lock_irqsave(&qpt->lock, flags);
+       if (map->page)
+               free_page(page);
+       else
+               map->page = (void *)page;
+       spin_unlock_irqrestore(&qpt->lock, flags);
+}
+
+
+static int alloc_qpn(struct ipath_qp_table *qpt, enum ib_qp_type type)
 {
        u32 i, offset, max_scan, qpn;
        struct qpn_map *map;
-       u32 ret;
+       u32 ret = -1;
+
+       if (type == IB_QPT_SMI)
+               ret = 0;
+       else if (type == IB_QPT_GSI)
+               ret = 1;
+
+       if (ret != -1) {
+               map = &qpt->map[0];
+               if (unlikely(!map->page)) {
+                       get_map_page(qpt, map);
+                       if (unlikely(!map->page)) {
+                               ret = -ENOMEM;
+                               goto bail;
+                       }
+               }
+               if (!test_and_set_bit(ret, map->page))
+                       atomic_dec(&map->n_free);
+               else
+                       ret = -EBUSY;
+               goto bail;
+       }
 
        qpn = qpt->last + 1;
        if (qpn >= QPN_MAX)
@@ -95,19 +135,7 @@ static u32 alloc_qpn(struct ipath_qp_table *qpt)
        max_scan = qpt->nmaps - !offset;
        for (i = 0;;) {
                if (unlikely(!map->page)) {
-                       unsigned long page = get_zeroed_page(GFP_KERNEL);
-                       unsigned long flags;
-
-                       /*
-                        * Free the page if someone raced with us
-                        * installing it:
-                        */
-                       spin_lock_irqsave(&qpt->lock, flags);
-                       if (map->page)
-                               free_page(page);
-                       else
-                               map->page = (void *)page;
-                       spin_unlock_irqrestore(&qpt->lock, flags);
+                       get_map_page(qpt, map);
                        if (unlikely(!map->page))
                                break;
                }
@@ -151,7 +179,7 @@ static u32 alloc_qpn(struct ipath_qp_table *qpt)
                qpn = mk_qpn(qpt, map, offset);
        }
 
-       ret = 0;
+       ret = -ENOMEM;
 
 bail:
        return ret;
@@ -180,29 +208,19 @@ static int ipath_alloc_qpn(struct ipath_qp_table *qpt, struct ipath_qp *qp,
                           enum ib_qp_type type)
 {
        unsigned long flags;
-       u32 qpn;
        int ret;
 
-       if (type == IB_QPT_SMI)
-               qpn = 0;
-       else if (type == IB_QPT_GSI)
-               qpn = 1;
-       else {
-               /* Allocate the next available QPN */
-               qpn = alloc_qpn(qpt);
-               if (qpn == 0) {
-                       ret = -ENOMEM;
-                       goto bail;
-               }
-       }
-       qp->ibqp.qp_num = qpn;
+       ret = alloc_qpn(qpt, type);
+       if (ret < 0)
+               goto bail;
+       qp->ibqp.qp_num = ret;
 
        /* Add the QP to the hash table. */
        spin_lock_irqsave(&qpt->lock, flags);
 
-       qpn %= qpt->max;
-       qp->next = qpt->table[qpn];
-       qpt->table[qpn] = qp;
+       ret %= qpt->max;
+       qp->next = qpt->table[ret];
+       qpt->table[ret] = qp;
        atomic_inc(&qp->refcount);
 
        spin_unlock_irqrestore(&qpt->lock, flags);
@@ -245,9 +263,7 @@ static void ipath_free_qp(struct ipath_qp_table *qpt, struct ipath_qp *qp)
        if (!fnd)
                return;
 
-       /* If QPN is not reserved, mark QPN free in the bitmap. */
-       if (qp->ibqp.qp_num > 1)
-               free_qpn(qpt, qp->ibqp.qp_num);
+       free_qpn(qpt, qp->ibqp.qp_num);
 
        wait_event(qp->wait, !atomic_read(&qp->refcount));
 }
@@ -270,8 +286,7 @@ void ipath_free_all_qps(struct ipath_qp_table *qpt)
 
                while (qp) {
                        nqp = qp->next;
-                       if (qp->ibqp.qp_num > 1)
-                               free_qpn(qpt, qp->ibqp.qp_num);
+                       free_qpn(qpt, qp->ibqp.qp_num);
                        if (!atomic_dec_and_test(&qp->refcount) ||
                            !ipath_destroy_qp(&qp->ibqp))
                                ipath_dbg("QP memory leak!\n");