IB/core: don't search the GID table twice

Previously, we've searched the GID table twice: first when we searched
the table for a GID matching the proposed new one, and second when we
didn't find a match, we searched again for an empty GID slot in the
table.  Instead, search the table once noting the first empty slot as
we search for our target GID.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
index 83aee7c..bfd0a65 100644 (file)
--- a/drivers/infiniband/core/cache.c
+++ b/drivers/infiniband/core/cache.c
@@ -208,19 +208,33 @@ static int del_gid(struct ib_device *ib_dev, u8 port,
 /* rwlock should be read locked */
 static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
                    const struct ib_gid_attr *val, bool default_gid,
-                   unsigned long mask)
+                   unsigned long mask, int *pempty)
 {
-       int i;
+       int i = 0;
+       int found = -1;
+       int empty = pempty ? -1 : 0;
 
-       for (i = 0; i < table->sz; i++) {
-               struct ib_gid_attr *attr = &table->data_vec[i].attr;
+       while (i < table->sz && (found < 0 || empty < 0)) {
+               struct ib_gid_table_entry *data = &table->data_vec[i];
+               struct ib_gid_attr *attr = &data->attr;
+               int curr_index = i;
 
+               i++;
 
-               if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID)
+               if (data->props & GID_TABLE_ENTRY_INVALID)
+                       continue;
+
+               if (empty < 0)
+                       if (!memcmp(&data->gid, &zgid, sizeof(*gid)) &&
+                           !memcmp(attr, &zattr, sizeof(*attr)) &&
+                           !data->props)
+                               empty = curr_index;
+
+               if (found >= 0)
                        continue;
 
                if (mask & GID_ATTR_FIND_MASK_GID &&
-                   memcmp(gid, &table->data_vec[i].gid, sizeof(*gid)))
+                   memcmp(gid, &data->gid, sizeof(*gid)))
                        continue;
 
                if (mask & GID_ATTR_FIND_MASK_NETDEV &&
@@ -228,14 +242,17 @@ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
                        continue;
 
                if (mask & GID_ATTR_FIND_MASK_DEFAULT &&
-                   !!(table->data_vec[i].props & GID_TABLE_ENTRY_DEFAULT) !=
+                   !!(data->props & GID_TABLE_ENTRY_DEFAULT) !=
                    default_gid)
                        continue;
 
-               break;
+               found = curr_index;
        }
 
-       return i == table->sz ? -1 : i;
+       if (pempty)
+               *pempty = empty;
+
+       return found;
 }
 
 static void make_default_gid(struct  net_device *dev, union ib_gid *gid)
@@ -252,6 +269,7 @@ int ib_cache_gid_add(struct ib_device *ib_dev, u8 port,
        int ix;
        int ret = 0;
        struct net_device *idev;
+       int empty;
 
        table = ports_table[port - rdma_start_port(ib_dev)];
 
@@ -278,18 +296,16 @@ int ib_cache_gid_add(struct ib_device *ib_dev, u8 port,
        write_lock_irq(&table->rwlock);
 
        ix = find_gid(table, gid, attr, false, GID_ATTR_FIND_MASK_GID |
-                     GID_ATTR_FIND_MASK_NETDEV);
+                     GID_ATTR_FIND_MASK_NETDEV, &empty);
        if (ix >= 0)
                goto out_unlock;
 
-       ix = find_gid(table, &zgid, NULL, false, GID_ATTR_FIND_MASK_GID |
-                     GID_ATTR_FIND_MASK_DEFAULT);
-       if (ix < 0) {
+       if (empty < 0) {
                ret = -ENOSPC;
                goto out_unlock;
        }
 
-       ret = add_gid(ib_dev, port, table, ix, gid, attr, false);
+       ret = add_gid(ib_dev, port, table, empty, gid, attr, false);
        if (!ret)
                dispatch_gid_change_event(ib_dev, port);
 
@@ -314,7 +330,8 @@ int ib_cache_gid_del(struct ib_device *ib_dev, u8 port,
        ix = find_gid(table, gid, attr, false,
                      GID_ATTR_FIND_MASK_GID      |
                      GID_ATTR_FIND_MASK_NETDEV   |
-                     GID_ATTR_FIND_MASK_DEFAULT);
+                     GID_ATTR_FIND_MASK_DEFAULT,
+                     NULL);
        if (ix < 0)
                goto out_unlock;
 
@@ -393,7 +410,7 @@ static int _ib_cache_gid_table_find(struct ib_device *ib_dev,
        for (p = 0; p < ib_dev->phys_port_cnt; p++) {
                table = ports_table[p];
                read_lock_irqsave(&table->rwlock, flags);
-               local_index = find_gid(table, gid, val, false, mask);
+               local_index = find_gid(table, gid, val, false, mask, NULL);
                if (local_index >= 0) {
                        if (index)
                                *index = local_index;
@@ -445,7 +462,7 @@ int ib_find_cached_gid_by_port(struct ib_device *ib_dev,
                mask |= GID_ATTR_FIND_MASK_NETDEV;
 
        read_lock_irqsave(&table->rwlock, flags);
-       local_index = find_gid(table, gid, &val, false, mask);
+       local_index = find_gid(table, gid, &val, false, mask, NULL);
        if (local_index >= 0) {
                if (index)
                        *index = local_index;
@@ -608,7 +625,7 @@ void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port,
 
        mutex_lock(&table->lock);
        write_lock_irq(&table->rwlock);
-       ix = find_gid(table, NULL, NULL, true, GID_ATTR_FIND_MASK_DEFAULT);
+       ix = find_gid(table, NULL, NULL, true, GID_ATTR_FIND_MASK_DEFAULT, NULL);
 
        /* Coudn't find default GID location */
        WARN_ON(ix < 0);