From bf399c2cadfa66d399d01d5a92a7bb0a112f1568 Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Tue, 5 Jun 2018 08:40:17 +0300 Subject: [PATCH] IB/core: Introduce GID attribute get, put and hold APIs This patch introduces three APIs, rdma_get_gid_attr(), rdma_put_gid_attr(), and rdma_hold_gid_attr() which expose the reference counting for GID table entries to the entire stack. The kref counting is based on the struct ib_gid_attr pointer Later patches will convert more cache query function to return struct ib_gid_attrs. Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/cache.c | 86 +++++++++++++++++++++++++++++++++++++++++ include/rdma/ib_cache.h | 4 ++ 2 files changed, 90 insertions(+) diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c index e569956c4e7a..d92525fb47c7 100644 --- a/drivers/infiniband/core/cache.c +++ b/drivers/infiniband/core/cache.c @@ -286,6 +286,11 @@ static void store_gid_entry(struct ib_gid_table *table, write_unlock_irq(&table->rwlock); } +static void get_gid_entry(struct ib_gid_table_entry *entry) +{ + kref_get(&entry->kref); +} + static void put_gid_entry(struct ib_gid_table_entry *entry) { kref_put(&entry->kref, schedule_free_gid); @@ -1208,6 +1213,87 @@ int ib_get_cached_port_state(struct ib_device *device, } EXPORT_SYMBOL(ib_get_cached_port_state); +/** + * rdma_get_gid_attr - Returns GID attributes for a port of a device + * at a requested gid_index, if a valid GID entry exists. + * @device: The device to query. + * @port_num: The port number on the device where the GID value + * is to be queried. + * @index: Index of the GID table entry whose attributes are to + * be queried. + * + * rdma_get_gid_attr() acquires reference count of gid attributes from the + * cached GID table. Caller must invoke rdma_put_gid_attr() to release + * reference to gid attribute regardless of link layer. + * + * Returns pointer to valid gid attribute or ERR_PTR for the appropriate error + * code. + */ +const struct ib_gid_attr * +rdma_get_gid_attr(struct ib_device *device, u8 port_num, int index) +{ + const struct ib_gid_attr *attr = ERR_PTR(-EINVAL); + struct ib_gid_table *table; + unsigned long flags; + + if (!rdma_is_port_valid(device, port_num)) + return ERR_PTR(-EINVAL); + + table = rdma_gid_table(device, port_num); + if (index < 0 || index >= table->sz) + return ERR_PTR(-EINVAL); + + read_lock_irqsave(&table->rwlock, flags); + if (!is_gid_entry_valid(table->data_vec[index])) + goto done; + + get_gid_entry(table->data_vec[index]); + attr = &table->data_vec[index]->attr; +done: + read_unlock_irqrestore(&table->rwlock, flags); + return attr; +} +EXPORT_SYMBOL(rdma_get_gid_attr); + +/** + * rdma_put_gid_attr - Release reference to the GID attribute + * @attr: Pointer to the GID attribute whose reference + * needs to be released. + * + * rdma_put_gid_attr() must be used to release reference whose + * reference is acquired using rdma_get_gid_attr() or any APIs + * which returns a pointer to the ib_gid_attr regardless of link layer + * of IB or RoCE. + * + */ +void rdma_put_gid_attr(const struct ib_gid_attr *attr) +{ + struct ib_gid_table_entry *entry = + container_of(attr, struct ib_gid_table_entry, attr); + + put_gid_entry(entry); +} +EXPORT_SYMBOL(rdma_put_gid_attr); + +/** + * rdma_hold_gid_attr - Get reference to existing GID attribute + * + * @attr: Pointer to the GID attribute whose reference + * needs to be taken. + * + * Increase the reference count to a GID attribute to keep it from being + * freed. Callers are required to already be holding a reference to attribute. + * + */ +void rdma_hold_gid_attr(const struct ib_gid_attr *attr) +{ + struct ib_gid_table_entry *entry = + container_of(attr, struct ib_gid_table_entry, attr); + + get_gid_entry(entry); +} +EXPORT_SYMBOL(rdma_hold_gid_attr); + static int config_non_roce_gid_cache(struct ib_device *device, u8 port, int gid_tbl_len) { diff --git a/include/rdma/ib_cache.h b/include/rdma/ib_cache.h index a5f249828115..00ccd00d0596 100644 --- a/include/rdma/ib_cache.h +++ b/include/rdma/ib_cache.h @@ -150,4 +150,8 @@ int ib_get_cached_port_state(struct ib_device *device, enum ib_port_state *port_active); bool rdma_is_zero_gid(const union ib_gid *gid); +const struct ib_gid_attr *rdma_get_gid_attr(struct ib_device *device, + u8 port_num, int index); +void rdma_put_gid_attr(const struct ib_gid_attr *attr); +void rdma_hold_gid_attr(const struct ib_gid_attr *attr); #endif /* _IB_CACHE_H */ -- 2.11.0