Commit 2d9b56d7 authored by Jonathan Rico's avatar Jonathan Rico Committed by Henrik Brix Andersen
Browse files

Bluetooth: L2CAP: remove metadata allocation 



The only thing we put in there is the CID and that fits comfortably into
the (at least) 4-byte void pointer `user_data`.

This removes the dependency between `CONFIG_BT_ATT_TX_COUNT` and
`CONFIG_BT_L2CAP_TX_BUF_COUNT` since previously there was still a need
for an L2CAP context for every TX'd buffer.

Signed-off-by: default avatarJonathan Rico <jonathan.rico@nordicsemi.no>
parent 3a4fd5e2

subsys/bluetooth/host/l2cap.c

+7 −79
Original line number Diff line number Diff line
@@ -70,41 +70,10 @@ NET_BUF_POOL_FIXED_DEFINE(disc_pool, 1, 
#define l2cap_lookup_ident(conn, ident) __l2cap_lookup_ident(conn, ident, false)

#define l2cap_remove_ident(conn, ident) __l2cap_lookup_ident(conn, ident, true)



struct l2cap_tx_meta_data {

	uint16_t cid;

	/* FIXME: remove this.

	 * `servers` gets messed up somehow if not present

	 */

	uint16_t pad;

};



struct l2cap_tx_meta {

	struct l2cap_tx_meta_data *data;

};



static struct l2cap_tx_meta_data l2cap_tx_meta_data_storage[CONFIG_BT_CONN_TX_MAX];

K_FIFO_DEFINE(free_l2cap_tx_meta_data);



static struct l2cap_tx_meta_data *alloc_tx_meta_data(void)

{

	return k_fifo_get(&free_l2cap_tx_meta_data, K_NO_WAIT);

}



static void free_tx_meta_data(struct l2cap_tx_meta_data *data)

{

	(void)memset(data, 0, sizeof(*data));

	k_fifo_put(&free_l2cap_tx_meta_data, data);

}



#define l2cap_tx_meta_data(buf) (((struct l2cap_tx_meta *)net_buf_user_data(buf))->data)



static sys_slist_t servers = SYS_SLIST_STATIC_INIT(&servers);



static void l2cap_tx_buf_destroy(struct bt_conn *conn, struct net_buf *buf, int err)

{

	struct l2cap_tx_meta_data *data = l2cap_tx_meta_data(buf);



	free_tx_meta_data(data);

	net_buf_unref(buf);

}

#endif /* CONFIG_BT_L2CAP_DYNAMIC_CHANNEL */
@@ -1848,14 +1817,11 @@ static void l2cap_chan_tx_resume(struct bt_l2cap_le_chan *ch) 


static void l2cap_chan_sdu_sent(struct bt_conn *conn, void *user_data, int err)

{

	struct l2cap_tx_meta_data *data = user_data;

	struct bt_l2cap_chan *chan;

	uint16_t cid = data->cid;

	uint16_t cid = POINTER_TO_UINT(user_data);



	LOG_DBG("conn %p CID 0x%04x err %d", conn, cid, err);



	free_tx_meta_data(data);



	if (err) {

		LOG_DBG("error %d when sending SDU", err);
@@ -1879,16 +1845,16 @@ static void l2cap_chan_sdu_sent(struct bt_conn *conn, void *user_data, int err) 


static void l2cap_chan_seg_sent(struct bt_conn *conn, void *user_data, int err)

{

	struct l2cap_tx_meta_data *data = user_data;

	struct bt_l2cap_chan *chan;

	uint16_t cid = POINTER_TO_UINT(user_data);



	LOG_DBG("conn %p CID 0x%04x err %d", conn, data->cid, err);

	LOG_DBG("conn %p CID 0x%04x err %d", conn, cid, err);



	if (err) {

		return;

	}



	chan = bt_l2cap_le_lookup_tx_cid(conn, data->cid);

	chan = bt_l2cap_le_lookup_tx_cid(conn, cid);

	if (!chan) {

		/* Received segment sent callback for disconnected channel */

		return;
@@ -1987,7 +1953,8 @@ static int l2cap_chan_le_send(struct bt_l2cap_le_chan *ch, 
	 * considered lost, as the lower layers are free to re-use it as they

	 * see fit. Reading from it later is obviously a no-no.

	 */

	err = bt_l2cap_send_cb(ch->chan.conn, ch->tx.cid, seg, cb, l2cap_tx_meta_data(buf));

	err = bt_l2cap_send_cb(ch->chan.conn, ch->tx.cid, seg,

			       cb, UINT_TO_POINTER(ch->tx.cid));



	if (err) {

		LOG_DBG("Unable to send seg %d", err);
@@ -2024,33 +1991,12 @@ static int l2cap_chan_le_send(struct bt_l2cap_le_chan *ch, 
}



/* return next netbuf fragment if present, also assign metadata */

static struct net_buf *prepare_next_frag(struct net_buf *parent,

					 struct l2cap_tx_meta_data *meta)

{

	/* this does an unref on `parent` */

	struct net_buf *next = net_buf_frag_del(NULL, parent);



	if (next) {

		LOG_DBG("process next frag: %p -> %p", parent, next);



		/* Copy the l2cap metadata ref to the next buffer in the chain.

		 * We need it to figure out which channel the PDU has been sent

		 * on, in order to either send the rest of the SDU or call the

		 * application callback.

		 */

		l2cap_tx_meta_data(next) = meta;

	}



	return next;

}



static int l2cap_chan_le_send_sdu(struct bt_l2cap_le_chan *ch,

				  struct net_buf **buf)

{

	int ret;

	size_t sent, rem_len, frag_len;

	struct net_buf *frag;

	struct l2cap_tx_meta_data *meta = l2cap_tx_meta_data(*buf);



	frag = *buf;

	if (!frag->len && frag->frags) {
@@ -2079,7 +2025,7 @@ static int l2cap_chan_le_send_sdu(struct bt_l2cap_le_chan *ch, 
		 * proceed to the next fragment of the netbuf chain.

		 */

		if (ret == frag_len) {

			frag = prepare_next_frag(frag, meta);

			frag = net_buf_frag_del(NULL, frag);

		}

	}
@@ -2821,15 +2767,6 @@ void bt_l2cap_init(void) 
	if (IS_ENABLED(CONFIG_BT_BREDR)) {

		bt_l2cap_br_init();

	}



#if defined(CONFIG_BT_L2CAP_DYNAMIC_CHANNEL)

	k_fifo_init(&free_l2cap_tx_meta_data);

	for (size_t i = 0; i < ARRAY_SIZE(l2cap_tx_meta_data_storage); i++) {

		(void)memset(&l2cap_tx_meta_data_storage[i], 0,

					sizeof(l2cap_tx_meta_data_storage[i]));

		k_fifo_put(&free_l2cap_tx_meta_data, &l2cap_tx_meta_data_storage[i]);

	}

#endif /* CONFIG_BT_L2CAP_DYNAMIC_CHANNEL */

}



#if defined(CONFIG_BT_L2CAP_DYNAMIC_CHANNEL)
@@ -3109,7 +3046,6 @@ int bt_l2cap_chan_disconnect(struct bt_l2cap_chan *chan) 


static int bt_l2cap_dyn_chan_send(struct bt_l2cap_le_chan *le_chan, struct net_buf *buf)

{

	struct l2cap_tx_meta_data *data;

	uint16_t sdu_len = net_buf_frags_len(buf);



	LOG_DBG("chan %p buf %p", le_chan, buf);
@@ -3128,12 +3064,6 @@ static int bt_l2cap_dyn_chan_send(struct bt_l2cap_le_chan *le_chan, struct net_b 
		return -EINVAL;

	}



	data = alloc_tx_meta_data();

	if (!data) {

		LOG_WRN("Unable to allocate TX context");

		return -ENOBUFS;

	}



	/* Prepend SDU "header".

	 *

	 * L2CAP LE CoC SDUs are segmented into PDUs and sent over so-called
@@ -3157,8 +3087,6 @@ static int bt_l2cap_dyn_chan_send(struct bt_l2cap_le_chan *le_chan, struct net_b 
	net_buf_push_le16(buf, sdu_len);



	/* Put buffer on TX queue */

	data->cid = le_chan->tx.cid;

	l2cap_tx_meta_data(buf) = data;

	net_buf_put(&le_chan->tx_queue, buf);



	/* Always process the queue in the same context */

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