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>

1 files changed, 53 insertions, 38 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_qp.c b/drivers/infiniband/hw/ipath/ipath_qp.c
index f671fd073253..16db9ac0b402 100644
--- 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");