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-rw-r--r--drivers/infiniband/core/core_priv.h1
-rw-r--r--drivers/infiniband/core/device.c13
-rw-r--r--include/rdma/ib_verbs.h24
3 files changed, 32 insertions, 6 deletions
diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 3cd830d52967..616734313f0c 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -267,7 +267,6 @@ static inline int ib_mad_enforce_security(struct ib_mad_agent_private *map,
#endif
struct ib_device *ib_device_get_by_index(u32 ifindex);
-void ib_device_put(struct ib_device *device);
/* RDMA device netlink */
void nldev_init(void);
void nldev_exit(void);
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 8872453e26c0..238ec42778ef 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -156,19 +156,26 @@ struct ib_device *ib_device_get_by_index(u32 index)
down_read(&lists_rwsem);
device = __ib_device_get_by_index(index);
if (device) {
- /* Do not return a device if unregistration has started. */
- if (!refcount_inc_not_zero(&device->refcount))
+ if (!ib_device_try_get(device))
device = NULL;
}
up_read(&lists_rwsem);
return device;
}
+/**
+ * ib_device_put - Release IB device reference
+ * @device: device whose reference to be released
+ *
+ * ib_device_put() releases reference to the IB device to allow it to be
+ * unregistered and eventually free.
+ */
void ib_device_put(struct ib_device *device)
{
if (refcount_dec_and_test(&device->refcount))
complete(&device->unreg_completion);
}
+EXPORT_SYMBOL(ib_device_put);
static struct ib_device *__ib_device_get_by_name(const char *name)
{
@@ -303,7 +310,6 @@ struct ib_device *ib_alloc_device(size_t size)
rwlock_init(&device->client_data_lock);
INIT_LIST_HEAD(&device->client_data_list);
INIT_LIST_HEAD(&device->port_list);
- refcount_set(&device->refcount, 1);
init_completion(&device->unreg_completion);
return device;
@@ -620,6 +626,7 @@ int ib_register_device(struct ib_device *device, const char *name,
goto cg_cleanup;
}
+ refcount_set(&device->refcount, 1);
device->reg_state = IB_DEV_REGISTERED;
list_for_each_entry(client, &client_list, list)
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index a3ceed3a040a..80debf5982ac 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2579,9 +2579,10 @@ struct ib_device {
const struct uapi_definition *driver_def;
enum rdma_driver_id driver_id;
+
/*
- * Provides synchronization between device unregistration and netlink
- * commands on a device. To be used only by core.
+ * Positive refcount indicates that the device is currently
+ * registered and cannot be unregistered.
*/
refcount_t refcount;
struct completion unreg_completion;
@@ -3926,6 +3927,25 @@ static inline bool ib_access_writable(int access_flags)
int ib_check_mr_status(struct ib_mr *mr, u32 check_mask,
struct ib_mr_status *mr_status);
+/**
+ * ib_device_try_get: Hold a registration lock
+ * device: The device to lock
+ *
+ * A device under an active registration lock cannot become unregistered. It
+ * is only possible to obtain a registration lock on a device that is fully
+ * registered, otherwise this function returns false.
+ *
+ * The registration lock is only necessary for actions which require the
+ * device to still be registered. Uses that only require the device pointer to
+ * be valid should use get_device(&ibdev->dev) to hold the memory.
+ *
+ */
+static inline bool ib_device_try_get(struct ib_device *dev)
+{
+ return refcount_inc_not_zero(&dev->refcount);
+}
+
+void ib_device_put(struct ib_device *device);
struct net_device *ib_get_net_dev_by_params(struct ib_device *dev, u8 port,
u16 pkey, const union ib_gid *gid,
const struct sockaddr *addr);