From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
This gives each client a unique ID and will let us move client_data to use
xarray, and revise the locking scheme.
clients have to be add/removed in strict FIFO/LIFO order as they
interdepend. To support this the client_ids are assigned to increase in
FIFO order. The existing linked list is kept to support reverse iteration
until xarray can get a reverse iteration API.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
---
drivers/infiniband/core/device.c | 50 ++++++++++++++++++++++++++++----
include/rdma/ib_verbs.h | 3 +-
2 files changed, 47 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 300a36beaa300c..f485e77223d429 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -65,15 +65,17 @@ struct workqueue_struct *ib_comp_unbound_wq;
struct workqueue_struct *ib_wq;
EXPORT_SYMBOL_GPL(ib_wq);
-/* The device_list and client_list contain devices and clients after their
+/* The device_list and clients contain devices and clients after their
* registration has completed, and the devices and clients are removed
* during unregistration. */
static LIST_HEAD(device_list);
static LIST_HEAD(client_list);
+#define CLIENT_REGISTERED XA_MARK_1
+static DEFINE_XARRAY_FLAGS(clients, XA_FLAGS_ALLOC);
/*
* device_mutex and lists_rwsem protect access to both device_list and
- * client_list. device_mutex protects writer access by device and client
+ * clients. device_mutex protects writer access by device and client
* registration / de-registration. lists_rwsem protects reader access to
* these lists. Iterators of these lists must lock it for read, while updates
* to the lists must be done with a write lock. A special case is when the
@@ -563,6 +565,7 @@ int ib_register_device(struct ib_device *device, const char *name)
{
int ret;
struct ib_client *client;
+ unsigned long index;
setup_dma_device(device);
@@ -607,7 +610,7 @@ int ib_register_device(struct ib_device *device, const char *name)
refcount_set(&device->refcount, 1);
- list_for_each_entry(client, &client_list, list)
+ xa_for_each_marked (&clients, index, client, CLIENT_REGISTERED)
if (!add_client_context(device, client) && client->add)
client->add(device);
@@ -679,6 +682,32 @@ void ib_unregister_device(struct ib_device *device)
}
EXPORT_SYMBOL(ib_unregister_device);
+static int assign_client_id(struct ib_client *client)
+{
+ int ret;
+
+ /*
+ * The add/remove callbacks must be called in FIFO/LIFO order. To
+ * achieve this we assign client_ids so they are sorted in
+ * registration order, and retain a linked list we can reverse iterate
+ * to get the LIFO order. The extra linked list can go away if xarray
+ * learns to reverse iterate.
+ */
+ if (list_empty(&client_list))
+ client->client_id = 0;
+ else
+ client->client_id =
+ list_last_entry(&client_list, struct ib_client, list)
+ ->client_id;
+ ret = xa_alloc(&clients, &client->client_id, INT_MAX, client,
+ GFP_KERNEL);
+ if (ret)
+ goto out;
+
+out:
+ return ret;
+}
+
/**
* ib_register_client - Register an IB client
* @client:Client to register
@@ -695,15 +724,21 @@ EXPORT_SYMBOL(ib_unregister_device);
int ib_register_client(struct ib_client *client)
{
struct ib_device *device;
+ int ret;
mutex_lock(&device_mutex);
+ ret = assign_client_id(client);
+ if (ret) {
+ mutex_unlock(&device_mutex);
+ return ret;
+ }
list_for_each_entry(device, &device_list, core_list)
if (!add_client_context(device, client) && client->add)
client->add(device);
down_write(&lists_rwsem);
- list_add_tail(&client->list, &client_list);
+ xa_set_mark(&clients, client->client_id, CLIENT_REGISTERED);
up_write(&lists_rwsem);
mutex_unlock(&device_mutex);
@@ -728,7 +763,7 @@ void ib_unregister_client(struct ib_client *client)
mutex_lock(&device_mutex);
down_write(&lists_rwsem);
- list_del(&client->list);
+ xa_clear_mark(&clients, client->client_id, CLIENT_REGISTERED);
up_write(&lists_rwsem);
list_for_each_entry(device, &device_list, core_list) {
@@ -764,6 +799,10 @@ void ib_unregister_client(struct ib_client *client)
kfree(found_context);
}
+ down_write(&lists_rwsem);
+ list_del(&client->list);
+ xa_erase(&clients, client->client_id);
+ up_write(&lists_rwsem);
mutex_unlock(&device_mutex);
}
EXPORT_SYMBOL(ib_unregister_client);
@@ -1417,6 +1456,7 @@ static void __exit ib_core_cleanup(void)
destroy_workqueue(ib_comp_wq);
/* Make sure that any pending umem accounting work is done. */
destroy_workqueue(ib_wq);
+ WARN_ON(!xa_empty(&clients));
}
MODULE_ALIAS_RDMA_NETLINK(RDMA_NL_LS, 4);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 76138ef4f839ea..84d7523984ee77 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2596,7 +2596,7 @@ struct ib_device {
};
struct ib_client {
- char *name;
+ const char *name;
void (*add) (struct ib_device *);
void (*remove)(struct ib_device *, void *client_data);
@@ -2623,6 +2623,7 @@ struct ib_client {
const struct sockaddr *addr,
void *client_data);
struct list_head list;
+ u32 client_id;
/* kverbs are not required by the client */
u8 no_kverbs_req:1;
--
2.20.1
