[PATCH 08/30] IB/core: Support find sgid index using a filter function

Somnath Kotur
2015-02-19T22:02:23Z

From: Matan Barak <matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

Sometimes a sgid index need to be found based on variable parameters.
For example, when the CM gets a packet from network, it needs to
match a sgid_index that matches the appropriate L2 attributes
of a packet. Extending the cache's API to include Ethernet L2
attribute is problematic, since they may be vastly extended
in the future. As a result, we add a find function that
gets a user filter function and searches the GID table
until a match is found.

Signed-off-by: Matan Barak <matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Somnath Kotur <somnath.kotur-laKkSmNT4hbQT0dZR+AlfA@public.gmane.org>
---
drivers/infiniband/core/cache.c | 24 +++++++++++
drivers/infiniband/core/core_priv.h | 9 ++++
drivers/infiniband/core/roce_gid_cache.c | 66 ++++++++++++++++++++++++++++++
include/rdma/ib_cache.h | 27 ++++++++++++
4 files changed, 126 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
index 882d491..ae86fe8 100644
--- a/drivers/infiniband/core/cache.c
+++ b/drivers/infiniband/core/cache.c
@@ -273,6 +273,30 @@ int ib_find_cached_gid_by_port(struct ib_device *device,
}
EXPORT_SYMBOL(ib_find_cached_gid_by_port);

+int ib_find_gid_by_filter(struct ib_device *device,
+ union ib_gid *gid,
+ u8 port_num,
+ bool (*filter)(const union ib_gid *gid,
+ const struct ib_gid_attr *,
+ void *),
+ void *context, u16 *index)
+{
+ /* Look for a RoCE device with the specified GID. */
+ if (!ib_cache_use_roce_gid_cache(device, port_num))
+ return roce_gid_cache_find_gid_by_filter(device, gid,
+ port_num, filter,
+ context, index);
+
+ /* Only RoCE GID cache supports filter function */
+ if (filter)
+ return -ENOSYS;
+
+ /* If no RoCE devices with the specified GID, look for IB device. */
+ return __ib_find_cached_gid_by_port(device, port_num,
+ gid, 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/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 411672f..d6e73f8 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -84,6 +84,15 @@ int roce_gid_cache_find_gid_by_port(struct ib_device *ib_dev, union ib_gid *gid,
enum ib_gid_type gid_type, u8 port,
struct net *net, int if_index, u16 *index);

+int roce_gid_cache_find_gid_by_filter(struct ib_device *ib_dev,
+ union ib_gid *gid,
+ u8 port,
+ bool (*filter)(const union ib_gid *gid,
+ const struct ib_gid_attr *,
+ void *),
+ void *context,
+ u16 *index);
+
int roce_gid_cache_is_active(struct ib_device *ib_dev, u8 port);

enum roce_gid_cache_default_mode {
diff --git a/drivers/infiniband/core/roce_gid_cache.c b/drivers/infiniband/core/roce_gid_cache.c
index 895b9c1..6017ba0 100644
--- a/drivers/infiniband/core/roce_gid_cache.c
+++ b/drivers/infiniband/core/roce_gid_cache.c
@@ -436,6 +436,72 @@ int roce_gid_cache_find_gid_by_port(struct ib_device *ib_dev, union ib_gid *gid,
return -ENOENT;
}

+int roce_gid_cache_find_gid_by_filter(struct ib_device *ib_dev,
+ union ib_gid *gid,
+ u8 port,
+ bool (*filter)(const union ib_gid *,
+ const struct ib_gid_attr *,
+ void *),
+ void *context,
+ u16 *index)
+{
+ struct ib_roce_gid_cache *cache;
+ unsigned int i;
+ bool found = false;
+
+ if (!ib_dev->cache.roce_gid_cache)
+ return -ENOSYS;
+
+ if (port < start_port(ib_dev) ||
+ port > start_port(ib_dev) + ib_dev->phys_port_cnt ||
+ rdma_port_get_link_layer(ib_dev, port) !=
+ IB_LINK_LAYER_ETHERNET)
+ return -ENOSYS;
+
+ cache = ib_dev->cache.roce_gid_cache[port - start_port(ib_dev)];
+
+ if (!cache->active)
+ return -ENOENT;
+
+ for (i = 0; i < cache->sz; i++) {
+ unsigned int orig_seq;
+ struct ib_gid_attr attr;
+
+ orig_seq = cache->data_vec[i].seq;
+ if (orig_seq == -1)
+ continue;
+ /* Make sure the sequence number we remeber was read
+ * before the gid cache entry content is read.
+ */
+ smp_rmb();
+
+ if (memcmp(gid, &cache->data_vec[i].gid, sizeof(*gid)))
+ continue;
+
+ memcpy(&attr, &cache->data_vec[i].attr, sizeof(attr));
+
+ rcu_read_lock();
+
+ /* Make sure we finished reading the attribute */
+ smp_rmb();
+ if (orig_seq == ACCESS_ONCE(cache->data_vec[i].seq))
+ if (!filter || filter(gid, &attr, context))
+ found = true;
+
+ rcu_read_unlock();
+
+ if (found)
+ break;
+ }
+
+ if (!found)
+ return -ENOENT;
+
+ if (index)
+ *index = i;
+ return 0;
+}
+
static struct ib_roce_gid_cache *alloc_roce_gid_cache(int sz)
{
struct ib_roce_gid_cache *cache =
diff --git a/include/rdma/ib_cache.h b/include/rdma/ib_cache.h
index 36b72bf..c6c1a51 100644
--- a/include/rdma/ib_cache.h
+++ b/include/rdma/ib_cache.h
@@ -111,6 +111,33 @@ int ib_find_cached_gid_by_port(struct ib_device *device,
struct net *net,
int if_index,
u16 *index);
+
+/**
+ * ib_find_cached_gid_by_port - 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 be NULL
+ * when RoCE GID cache isn't supported on the respective device's port.
+ * @index: The index into the cached GID table where the GID was found. This
+ * parameter may be NULL.
+ *
+ * ib_find_cached_gid_by_port() searches for the specified GID value in
+ * the local software cache.
+ */
+int ib_find_gid_by_filter(struct ib_device *device,
+ 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.