Bluetooth: L2CAP: Move fixed channels to its own section in ROM

This changes the declaration of fixed channels to be statically defined
with use of BT_L2CAP_CHANNEL_DEFINE since fixed channels are never
unregistered.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/linker/common-rom.ld

@@ -77,6 +77,22 @@
 	} GROUP_LINK_IN(ROMABLE_REGION)
 #endif
 
+	SECTION_DATA_PROLOGUE(_bt_channels_area,,SUBALIGN(4))
+	{
+		_bt_channels_start = .;
+		KEEP(*(SORT_BY_NAME("._bt_channels.static.*")))
+		_bt_channels_end = .;
+	} GROUP_LINK_IN(ROMABLE_REGION)
+
+#if defined(CONFIG_BT_BREDR)
+	SECTION_DATA_PROLOGUE(_bt_br_channels_area,,SUBALIGN(4))
+	{
+		_bt_br_channels_start = .;
+		KEEP(*(SORT_BY_NAME("._bt_br_channels.static.*")))
+		_bt_br_channels_end = .;
+	} GROUP_LINK_IN(ROMABLE_REGION)
+#endif
+
 	SECTION_DATA_PROLOGUE(_bt_services_area,,SUBALIGN(4))
 	{
 		_bt_services_start = .;

scripts/sanitycheck

@@ -909,8 +909,8 @@ class SizeCalculator:
     # These get copied into RAM only on non-XIP
     ro_sections = ["text", "ctors", "init_array", "reset", "object_access",
                    "rodata", "devconfig", "net_l2", "vector", "sw_isr_table",
-                   "_bt_settings_area", "_bt_services_area", "vectors",
+                   "_bt_settings_area", "_bt_channels_area","_bt_services_area",
-                   "net_socket_register"]
+                   "vectors", "net_socket_register"]
 
     def __init__(self, filename, extra_sections):
         """Constructor

subsys/bluetooth/host/att.c

@@ -2174,15 +2174,10 @@ static int bt_att_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
 	return -ENOMEM;
 }
 
+BT_L2CAP_CHANNEL_DEFINE(att_fixed_chan, BT_L2CAP_CID_ATT, bt_att_accept);
+
 void bt_att_init(void)
 {
-	static struct bt_l2cap_fixed_chan chan = {
-		.cid		= BT_L2CAP_CID_ATT,
-		.accept		= bt_att_accept,
-	};
-
-	bt_l2cap_le_fixed_chan_register(&chan);
-
 	bt_gatt_init();
 }
 

subsys/bluetooth/host/l2cap.c

@@ -49,7 +49,9 @@
 #define L2CAP_CONN_TIMEOUT	K_SECONDS(40)
 #define L2CAP_DISC_TIMEOUT	K_SECONDS(2)
 
-static sys_slist_t le_channels;
+/* Linker-defined symbols bound to the bt_l2cap_fixed_chan structs */
+extern const struct bt_l2cap_fixed_chan _bt_channels_start[];
+extern const struct bt_l2cap_fixed_chan _bt_channels_end[];
 
 #if defined(CONFIG_BT_L2CAP_DYNAMIC_CHANNEL)
 /* Size of MTU is based on the maximum amount of data the buffer can hold
@@ -87,13 +89,6 @@ static u8_t get_ident(void)
 	return ident;
 }
 
-void bt_l2cap_le_fixed_chan_register(struct bt_l2cap_fixed_chan *chan)
-{
-	BT_DBG("CID 0x%04x", chan->cid);
-
-	sys_slist_append(&le_channels, &chan->node);
-}
-
 #if defined(CONFIG_BT_L2CAP_DYNAMIC_CHANNEL)
 static struct bt_l2cap_le_chan *l2cap_chan_alloc_cid(struct bt_conn *conn,
 						     struct bt_l2cap_chan *chan)
@@ -304,7 +299,7 @@ static bool l2cap_chan_add(struct bt_conn *conn, struct bt_l2cap_chan *chan,
 
 void bt_l2cap_connected(struct bt_conn *conn)
 {
-	struct bt_l2cap_fixed_chan *fchan;
+	const struct bt_l2cap_fixed_chan *fchan;
 	struct bt_l2cap_chan *chan;
 
 	if (IS_ENABLED(CONFIG_BT_BREDR) &&
@@ -313,7 +308,7 @@ void bt_l2cap_connected(struct bt_conn *conn)
 		return;
 	}
 
-	SYS_SLIST_FOR_EACH_CONTAINER(&le_channels, fchan, node) {
+	for (fchan = _bt_channels_start; fchan < _bt_channels_end; fchan++) {
 		struct bt_l2cap_le_chan *ch;
 
 		if (fchan->accept(conn, &chan) < 0) {
@@ -732,6 +727,12 @@ static u16_t le_err_to_result(int err)
 		return BT_L2CAP_LE_ERR_AUTHORIZATION;
 	case -EPERM:
 		return BT_L2CAP_LE_ERR_KEY_SIZE;
+	case -ENOTSUP:
+		/* This handle the cases where a fixed channel is registered but
+		 * for some reason (e.g. controller not suporting a feature)
+		 * cannot be used.
+		 */
+		return BT_L2CAP_LE_ERR_PSM_NOT_SUPP;
 	default:
 		return BT_L2CAP_LE_ERR_UNACCEPT_PARAMS;
 	}
@@ -1668,15 +1669,10 @@ static int l2cap_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
 	return -ENOMEM;
 }
 
+BT_L2CAP_CHANNEL_DEFINE(le_fixed_chan, BT_L2CAP_CID_LE_SIG, l2cap_accept);
+
 void bt_l2cap_init(void)
 {
-	static struct bt_l2cap_fixed_chan chan = {
-		.cid	= BT_L2CAP_CID_LE_SIG,
-		.accept	= l2cap_accept,
-	};
-
-	bt_l2cap_le_fixed_chan_register(&chan);
-
 	if (IS_ENABLED(CONFIG_BT_BREDR)) {
 		bt_l2cap_br_init();
 	}

subsys/bluetooth/host/l2cap_br.c

@@ -78,7 +78,10 @@ enum {
 };
 
 static sys_slist_t br_servers;
-static sys_slist_t br_fixed_channels;
+
+/* Linker-defined symbols bound to the bt_l2cap_fixed_chan structs */
+extern const struct bt_l2cap_fixed_chan _bt_br_channels_start[];
+extern const struct bt_l2cap_fixed_chan _bt_br_channels_end[];
 
 /* Pool for outgoing BR/EDR signaling packets, min MTU is 48 */
 NET_BUF_POOL_DEFINE(br_sig_pool, CONFIG_BT_MAX_CONN,
@@ -383,11 +386,12 @@ done:
 
 static u8_t get_fixed_channels_mask(void)
 {
-	struct bt_l2cap_fixed_chan *fchan;
+	const struct bt_l2cap_fixed_chan *fchan;
 	u8_t mask = 0U;
 
 	/* this needs to be enhanced if AMP Test Manager support is added */
-	SYS_SLIST_FOR_EACH_CONTAINER(&br_fixed_channels, fchan, node) {
+	for (fchan = _bt_br_channels_start; fchan < _bt_br_channels_end;
+	     fchan++) {
 		mask |= BIT(fchan->cid);
 	}
 
@@ -450,10 +454,11 @@ static int l2cap_br_info_req(struct bt_l2cap_br *l2cap, u8_t ident,
 
 void bt_l2cap_br_connected(struct bt_conn *conn)
 {
-	struct bt_l2cap_fixed_chan *fchan;
+	const struct bt_l2cap_fixed_chan *fchan;
 	struct bt_l2cap_chan *chan;
 
-	SYS_SLIST_FOR_EACH_CONTAINER(&br_fixed_channels, fchan, node) {
+	for (fchan = _bt_br_channels_start; fchan < _bt_br_channels_end;
+	     fchan++) {
 		struct bt_l2cap_br_chan *ch;
 
 		if (!fchan->accept) {
@@ -1545,24 +1550,12 @@ static int l2cap_br_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
 	return -ENOMEM;
 }
 
-void bt_l2cap_br_fixed_chan_register(struct bt_l2cap_fixed_chan *chan)
+BT_L2CAP_CHANNEL_DEFINE(br_fixed_chan, BT_L2CAP_CID_BR_SIG, l2cap_br_accept);
-{
-	BT_DBG("CID 0x%04x", chan->cid);
-
-	sys_slist_append(&br_fixed_channels, &chan->node);
-}
 
 void bt_l2cap_br_init(void)
 {
-	static struct bt_l2cap_fixed_chan chan_br = {
-			.cid	= BT_L2CAP_CID_BR_SIG,
-			.accept = l2cap_br_accept,
-			};
-
 	sys_slist_init(&br_servers);
 
-	bt_l2cap_br_fixed_chan_register(&chan_br);
-
 	if (IS_ENABLED(CONFIG_BT_RFCOMM)) {
 		bt_rfcomm_init();
 	}

subsys/bluetooth/host/l2cap_internal.h

@@ -202,11 +202,14 @@ struct bt_l2cap_le_credits {
 struct bt_l2cap_fixed_chan {
 	u16_t		cid;
 	int (*accept)(struct bt_conn *conn, struct bt_l2cap_chan **chan);
-	sys_snode_t	node;
 };
 
-/* Register a fixed L2CAP channel for L2CAP */
+#define BT_L2CAP_CHANNEL_DEFINE(_name, _cid, _accept)		\
-void bt_l2cap_le_fixed_chan_register(struct bt_l2cap_fixed_chan *chan);
+	const struct bt_l2cap_fixed_chan _name __aligned(4)	\
+			__in_section(_bt_channels, static, _name) = { \
+				.cid = _cid,			\
+				.accept = _accept,		\
+			}
 
 /* Notify L2CAP channels of a new connection */
 void bt_l2cap_connected(struct bt_conn *conn);

subsys/bluetooth/host/smp.c

@@ -1365,6 +1365,16 @@ static int bt_smp_br_recv(struct bt_l2cap_chan *chan, struct net_buf *buf)
 	return 0;
 }
 
+static bool br_sc_supported(void)
+{
+	if (IS_ENABLED(CONFIG_BT_SMP_FORCE_BREDR)) {
+		BT_WARN("Enabling BR/EDR SMP without BR/EDR SC support");
+		return true;
+	}
+
+	return BT_FEAT_SC(bt_dev.features);
+}
+
 static int bt_smp_br_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
 {
 	static struct bt_l2cap_chan_ops ops = {
@@ -1374,6 +1384,11 @@ static int bt_smp_br_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
 	};
 	int i;
 
+	/* Check BR/EDR SC is supported */
+	if (!br_sc_supported()) {
+		return -ENOTSUP;
+	}
+
 	BT_DBG("conn %p handle %u", conn, conn->handle);
 
 	for (i = 0; i < ARRAY_SIZE(bt_smp_pool); i++) {
@@ -1484,16 +1499,6 @@ int bt_smp_br_send_pairing_req(struct bt_conn *conn)
 
 	return 0;
 }
-
-static bool br_sc_supported(void)
-{
-	if (IS_ENABLED(CONFIG_BT_SMP_FORCE_BREDR)) {
-		BT_WARN("Enabling BR/EDR SMP without BR/EDR SC support");
-		return true;
-	}
-
-	return BT_FEAT_SC(bt_dev.features);
-}
 #endif /* CONFIG_BT_BREDR */
 
 static void smp_reset(struct bt_smp *smp)
@@ -4823,12 +4828,14 @@ static bool le_sc_supported(void)
 	       BT_CMD_TEST(bt_dev.supported_commands, 34, 2);
 }
 
+BT_L2CAP_CHANNEL_DEFINE(smp_fixed_chan, BT_L2CAP_CID_SMP, bt_smp_accept);
+#if defined(CONFIG_BT_BREDR)
+BT_L2CAP_CHANNEL_DEFINE(smp_br_fixed_chan, BT_L2CAP_CID_BR_SMP,
+			bt_smp_br_accept);
+#endif /* CONFIG_BT_BREDR */
+
 int bt_smp_init(void)
 {
-	static struct bt_l2cap_fixed_chan chan = {
-		.cid		= BT_L2CAP_CID_SMP,
-		.accept		= bt_smp_accept,
-	};
 	static struct bt_pub_key_cb pub_key_cb = {
 		.func           = bt_smp_pkey_ready,
 	};
@@ -4839,19 +4846,6 @@ int bt_smp_init(void)
 		return -ENOENT;
 	}
 
-	bt_l2cap_le_fixed_chan_register(&chan);
-#if defined(CONFIG_BT_BREDR)
-	/* Register BR/EDR channel only if BR/EDR SC is supported */
-	if (br_sc_supported()) {
-		static struct bt_l2cap_fixed_chan br_chan = {
-			.cid		= BT_L2CAP_CID_BR_SMP,
-			.accept		= bt_smp_br_accept,
-		};
-
-		bt_l2cap_br_fixed_chan_register(&br_chan);
-	}
-#endif
-
 	BT_DBG("LE SC %s", sc_supported ? "enabled" : "disabled");
 
 	bt_pub_key_gen(&pub_key_cb);

subsys/bluetooth/host/smp_null.c

@@ -93,14 +93,9 @@ static int bt_smp_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
 	return -ENOMEM;
 }
 
+BT_L2CAP_CHANNEL_DEFINE(smp_fixed_chan, BT_L2CAP_CID_SMP, bt_smp_accept);
+
 int bt_smp_init(void)
 {
-	static struct bt_l2cap_fixed_chan chan = {
-		.cid	= BT_L2CAP_CID_SMP,
-		.accept	= bt_smp_accept,
-	};
-
-	bt_l2cap_le_fixed_chan_register(&chan);
-
 	return 0;
 }