IB/cache: Add ib_find_gid_by_filter cache API

GID cache API users might want to search for GIDs with specific
attributes rather than just specifying GID, net device and port.
This is used in a later patch, where we find the sgid index by
L2 Ethernet attributes.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-By: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

2 files changed, 101 insertions, 0 deletions

diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
index 639a7266bfaf..89bebeada38b 100644
--- a/drivers/infiniband/core/cache.c
+++ b/drivers/infiniband/core/cache.c
@@ -440,6 +440,81 @@ int ib_find_cached_gid_by_port(struct ib_device *ib_dev,
 }
 EXPORT_SYMBOL(ib_find_cached_gid_by_port);
 
+/**
+ * ib_find_gid_by_filter - Returns the GID table index where a specified
+ * GID value occurs
+ * @device: The device to query.
+ * @gid: The GID value to search for.
+ * @port_num: The port number of the device where the GID value could be
+ *   searched.
+ * @filter: The filter function is executed on any matching GID in the table.
+ *   If the filter function returns true, the corresponding index is returned,
+ *   otherwise, we continue searching the GID table. It's guaranteed that
+ *   while filter is executed, ndev field is valid and the structure won't
+ *   change. filter is executed in an atomic context. filter must not be NULL.
+ * @index: The index into the cached GID table where the GID was found.  This
+ *   parameter may be NULL.
+ *
+ * ib_cache_gid_find_by_filter() searches for the specified GID value
+ * of which the filter function returns true in the port's GID table.
+ * This function is only supported on RoCE ports.
+ *
+ */
+static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev,
+                                       const union ib_gid *gid,
+                                       u8 port,
+                                       bool (*filter)(const union ib_gid *,
+                                                      const struct ib_gid_attr *,
+                                                      void *),
+                                       void *context,
+                                       u16 *index)
+{
+        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
+        struct ib_gid_table *table;
+        unsigned int i;
+        bool found = false;
+
+        if (!ports_table)
+                return -EOPNOTSUPP;
+
+        if (port < rdma_start_port(ib_dev) ||
+            port > rdma_end_port(ib_dev) ||
+            !rdma_protocol_roce(ib_dev, port))
+                return -EPROTONOSUPPORT;
+
+        table = ports_table[port - rdma_start_port(ib_dev)];
+
+        for (i = 0; i < table->sz; i++) {
+                struct ib_gid_attr attr;
+                unsigned long flags;
+
+                read_lock_irqsave(&table->data_vec[i].lock, flags);
+                if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID)
+                        goto next;
+
+                if (memcmp(gid, &table->data_vec[i].gid, sizeof(*gid)))
+                        goto next;
+
+                memcpy(&attr, &table->data_vec[i].attr, sizeof(attr));
+
+                if (filter(gid, &attr, context))
+                        found = true;
+
+next:
+                read_unlock_irqrestore(&table->data_vec[i].lock, flags);
+
+                if (found)
+                        break;
+        }
+
+        if (!found)
+                return -ENOENT;
+
+        if (index)
+                *index = i;
+        return 0;
+}
+
 static struct ib_gid_table *alloc_gid_table(int sz)
 {
         unsigned int i;
@@ -670,6 +745,24 @@ int ib_find_cached_gid(struct ib_device *device,
 }
 EXPORT_SYMBOL(ib_find_cached_gid);
 
+int ib_find_gid_by_filter(struct ib_device *device,
+                          const union ib_gid *gid,
+                          u8 port_num,
+                          bool (*filter)(const union ib_gid *gid,
+                                         const struct ib_gid_attr *,
+                                         void *),
+                          void *context, u16 *index)
+{
+        /* Only RoCE GID table supports filter function */
+        if (!rdma_cap_roce_gid_table(device, port_num) && filter)
+                return -EPROTONOSUPPORT;
+
+        return ib_cache_gid_find_by_filter(device, gid,
+                                           port_num, filter,
+                                           context, index);
+}
+EXPORT_SYMBOL(ib_find_gid_by_filter);
+
 int ib_get_cached_pkey(struct ib_device *device,
                        u8                port_num,
                        int               index,
diff --git a/include/rdma/ib_cache.h b/include/rdma/ib_cache.h
index 679d7ca6a3ee..269a27cf0a46 100644
--- a/include/rdma/ib_cache.h
+++ b/include/rdma/ib_cache.h
@@ -93,6 +93,14 @@ int ib_find_cached_gid_by_port(struct ib_device *device,
                                u8               port_num,
                                struct net_device *ndev,
                                u16              *index);
+
+int ib_find_gid_by_filter(struct ib_device *device,
+                          const union ib_gid *gid,
+                          u8 port_num,
+                          bool (*filter)(const union ib_gid *gid,
+                                         const struct ib_gid_attr *,
+                                         void *),
+                          void *context, u16 *index);
 /**
  * ib_get_cached_pkey - Returns a cached PKey table entry
  * @device: The device to query.