[rdma-next v2 14/33] RDMA/core: Add and expose static device index

Leon Romanovsky
2017-08-10T11:08:08Z

This patch adds static device index in similar fashion to
already available in netdev world (struct net->ifindex).

In downstream patches, the RDMA nelink will use this idx-to-ib_device
conversion, so as part of this commit, we are exposing the translation
function to be visible for IB/core users.

Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/core/core_priv.h | 5 +++++
drivers/infiniband/core/device.c | 37 ++++++++++++++++++++++++++++++++++++-
include/rdma/ib_verbs.h | 2 ++
3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 0c175590cf92..cbdcc81e1df8 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -309,4 +309,9 @@ static inline int ib_mad_enforce_security(struct ib_mad_agent_private *map,
return 0;
}
#endif
+
+struct ib_device *__ib_device_get_by_index(u32 ifindex);
+/* RDMA device netlink */
+void nldev_init(void);
+void nldev_exit(void);
#endif /* _CORE_PRIV_H */
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 8828f26250a8..deae8b940994 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -134,6 +134,17 @@ static int ib_device_check_mandatory(struct ib_device *device)
return 0;
}

+struct ib_device *__ib_device_get_by_index(u32 index)
+{
+ struct ib_device *device;
+
+ list_for_each_entry(device, &device_list, core_list)
+ if (device->index == index)
+ return device;
+
+ return NULL;
+}
+
static struct ib_device *__ib_device_get_by_name(const char *name)
{
struct ib_device *device;
@@ -145,7 +156,6 @@ static struct ib_device *__ib_device_get_by_name(const char *name)
return NULL;
}

-
static int alloc_name(char *name)
{
unsigned long *inuse;
@@ -394,6 +404,30 @@ static int ib_security_change(struct notifier_block *nb, unsigned long event,
return NOTIFY_OK;
}

+/**
+ * __dev_new_index - allocate an device index
+ *
+ * Returns a suitable unique value for a new device interface
+ * number. It assumes that there are less than 2^32-1 ib devices
+ * will be present in the system.
+ */
+static u32 __dev_new_index(void)
+{
+ /*
+ * The device index to allow stable naming.
+ * Similar to struct net -> ifindex.
+ */
+ static u32 index;
+
+ for (;;) {
+ if (!(++index))
+ index = 1;
+
+ if (!__ib_device_get_by_index(index))
+ return index;
+ }
+}
+
/**
* ib_register_device - Register an IB device with IB core
* @device:Device to register
@@ -492,6 +526,7 @@ int ib_register_device(struct ib_device *device,
if (client->add && !add_client_context(device, client))
client->add(device);

+ device->index = __dev_new_index();
down_write(&lists_rwsem);
list_add_tail(&device->core_list, &device_list);
up_write(&lists_rwsem);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 1082b4c81b2c..3391df5fdc9c 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2298,6 +2298,8 @@ struct ib_device {
struct rdmacg_device cg_device;
#endif

+ u32 index;
+
/**
* The following mandatory functions are used only at device
* registration. Keep functions such as these at the end of this