From: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
Workqueue might be used for A2MP tasks which cannot be run from
L2CAP of HCI code due to unsafe locking scenarios. For example in
l2cap_security_cfm and l2cap_conn_start we need to discover and
create amp manager from the code surrounded with &conn->chan_lock
and &chan->lock.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
---
include/net/bluetooth/a2mp.h | 2 ++
net/bluetooth/a2mp.c | 38 ++++++++++++++++++++++++++++++++++++++
net/bluetooth/l2cap_core.c | 6 ++++++
3 files changed, 46 insertions(+)
diff --git a/include/net/bluetooth/a2mp.h b/include/net/bluetooth/a2mp.h
index 8ba236c..345fbc6 100644
--- a/include/net/bluetooth/a2mp.h
+++ b/include/net/bluetooth/a2mp.h
@@ -129,5 +129,7 @@ int amp_mgr_put(struct amp_mgr *mgr);
struct l2cap_chan *a2mp_channel_create(struct l2cap_conn *conn,
struct sk_buff *skb);
void a2mp_send(struct amp_mgr *mgr, u8 code, u8 ident, u16 len, void *data);
+int a2mp_init(void);
+void a2mp_exit(void);
#endif /* __A2MP_H */
diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index 6f719d3..26a225b 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -19,6 +19,8 @@
#include <net/bluetooth/amp.h>
#include <net/bluetooth/pal.h>
+static struct workqueue_struct *amp_workqueue;
+
/* A2MP build & send command helper functions */
static struct a2mp_cmd *__a2mp_build(u8 code, u8 ident, u16 len, void *data)
{
@@ -767,3 +769,39 @@ struct l2cap_chan *a2mp_channel_create(struct l2cap_conn *conn,
return mgr->a2mp_chan;
}
+
+void l2cap_discover_amp(struct l2cap_chan *chan)
+{
+ struct a2mp_discov_req req;
+ struct l2cap_conn *conn = chan->conn;
+ struct amp_mgr *mgr = conn->hcon->amp_mgr;
+
+ BT_DBG("%p", conn);
+
+ if (!mgr) {
+ mgr = amp_mgr_create(conn);
+ if (!mgr)
+ return;
+ }
+
+ mgr->bredr_chan = chan;
+
+ req.mtu = cpu_to_le16(L2CAP_A2MP_DEFAULT_MTU);
+ req.ext_feat = 0;
+ a2mp_send(mgr, A2MP_DISCOVER_REQ, 1, sizeof(req), &req);
+}
+
+int a2mp_init(void)
+{
+ amp_workqueue = create_singlethread_workqueue("a2mp");
+ if (!amp_workqueue)
+ return -EPERM;
+
+ return 0;
+}
+
+void a2mp_exit(void)
+{
+ flush_workqueue(amp_workqueue);
+ destroy_workqueue(amp_workqueue);
+}
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 4dbbb79..d4e99d6 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -5730,11 +5730,17 @@ int __init l2cap_init(void)
BT_ERR("Failed to create L2CAP debug file");
}
+ if (enable_hs)
+ return a2mp_init();
+
return 0;
}
void l2cap_exit(void)
{
+ if (enable_hs)
+ a2mp_exit();
+
debugfs_remove(l2cap_debugfs);
l2cap_cleanup_sockets();
}
--
1.7.9.5
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