Bluetooth: Kconfig: Introduce BLUETOOTH_COMBINED_RX_BUF option

If the controller doesn't need ACL host flow control it may want to
optimize and use a single pool for incoming data.

Change-Id: Iec2a69bd2d7a127c7329d0423ab5ce6b73cb9904
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/bluetooth/buf.h

@@ -47,6 +47,12 @@ enum bt_buf_type {
 /** Minimum amount of user data size for buffers passed to the stack. */
 #define BT_BUF_USER_DATA_MIN 4
 
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+/** Data size neeed for HCI RX buffers */
+#define BT_BUF_RX_SIZE (CONFIG_BLUETOOTH_HCI_RECV_RESERVE + \
+			sizeof(struct bt_hci_acl_hdr) + \
+			CONFIG_BLUETOOTH_RX_BUF_LEN)
+#else
 /** Data size neeed for HCI event buffers */
 #define BT_BUF_EVT_SIZE (CONFIG_BLUETOOTH_HCI_RECV_RESERVE + \
 			 sizeof(struct bt_hci_evt_hdr) + \
@@ -57,6 +63,7 @@ enum bt_buf_type {
 			    sizeof(struct bt_hci_acl_hdr) + \
 			    4 /* L2CAP header size */ + \
 			    CONFIG_BLUETOOTH_L2CAP_IN_MTU)
+#endif
 
 /** Allocate a buffer for an HCI event
  *

subsys/bluetooth/host/Kconfig

@@ -44,6 +44,11 @@ config BLUETOOTH_HCI_HOST
 	select TINYCRYPT_SHA256_HMAC
 	select TINYCRYPT_SHA256_HMAC_PRNG
 
+config BLUETOOTH_COMBINED_RX_BUF
+	# Virtual option usually set by the controller to request a
+	# combined pool for incoming buffers.
+	bool
+
 config BLUETOOTH_HCI_CMD_COUNT
 	int "Number of HCI command buffers"
 	default 2
@@ -60,6 +65,13 @@ config BLUETOOTH_MAX_CMD_LEN
 	help
 	  Maximum length of each HCI command.
 
+if !BLUETOOTH_COMBINED_RX_BUF
+config BLUETOOTH_HOST_FLOW_CONTROL
+	# Virtual option usually set by the HCI driver to state that ACL
+	# host flow control is needed.
+	bool
+	depends on BLUETOOTH_CONN
+
 config BLUETOOTH_HCI_EVT_COUNT
 	int "Number of HCI event buffers"
 	default 4
@@ -81,6 +93,25 @@ config BLUETOOTH_MAX_EVT_LEN
 	  for LE is the Command Complete for Read Local Supported
 	  Commands. It is a 3 byte Command Complete header + 65 byte
 	  return parameters = 68 bytes in total.
+endif # !BLUETOOTH_COMBINED_RX_BUF
+
+if BLUETOOTH_COMBINED_RX_BUF
+config BLUETOOTH_RX_BUF_COUNT
+	int "Number of HCI RX buffers"
+	default 1
+	range 1 255
+	help
+	  Number of buffers available for incoming ACL packets or HCI events
+	  from the controller.
+
+config BLUETOOTH_RX_BUF_LEN
+	int "Maximum supported HCI RX buffer length"
+	default 70
+	default 253 if BLUETOOTH_BREDR
+	range 70 2000
+	help
+	  Maximum data size for each HCI RX buffer.
+endif # BLUETOOTH_COMBINED_RX_BUF
 
 config BLUETOOTH_UART_TO_HOST_DEV_NAME
 	string "Device Name of UART Device to an external Bluetooth Host"
@@ -91,7 +122,7 @@ config BLUETOOTH_UART_TO_HOST_DEV_NAME
 	  to connect to an external Bluetooth Host when Zephyr is
 	  acting as a Bluetooth Controller.
 
-if BLUETOOTH_CONN || BLUETOOTH_HCI_RAW
+if !BLUETOOTH_COMBINED_RX_BUF && (BLUETOOTH_CONN || BLUETOOTH_HCI_RAW)
 config BLUETOOTH_ACL_IN_COUNT
 	int "Number of incoming ACL data buffers"
 	default 6
@@ -109,7 +140,7 @@ config BLUETOOTH_L2CAP_IN_MTU
 	range 65 1300 if BLUETOOTH_SMP
 	help
 	  Maximum size of each incoming L2CAP PDU.
-endif # BLUETOOTH_CONN || BLUETOOTH_HCI_RAW
+endif # !BLUETOOTH_COMBINED_RX_BUF && (BLUETOOTH_CONN || BLUETOOTH_HCI_RAW)
 
 if BLUETOOTH_HCI_HOST
 config BLUETOOTH_INTERNAL_STORAGE
@@ -154,7 +185,8 @@ config BLUETOOTH_ATT_MTU
 	default 23
 	default 50 if BLUETOOTH_SMP # BLUETOOTH_L2CAP_IN_MTU is big enough
 				    # for two complete ACL packets
-	range 23 BLUETOOTH_L2CAP_IN_MTU
+	range 23 BLUETOOTH_L2CAP_IN_MTU if !BLUETOOTH_COMBINED_RX_BUF
+	range 23 BLUETOOTH_RX_BUF_LEN if BLUETOOTH_COMBINED_RX_BUF
 	help
 	  The MTU for the ATT channel. The minimum and default is 23,
 	  whereas the maximum is limited by CONFIG_BLUETOOTH_L2CAP_IN_MTU.
@@ -458,9 +490,11 @@ config BLUETOOTH_RFCOMM
 
 config BLUETOOTH_RFCOMM_L2CAP_MTU
 	int "L2CAP MTU for RFCOMM frames"
-	default BLUETOOTH_L2CAP_IN_MTU
+	default BLUETOOTH_L2CAP_IN_MTU if !BLUETOOTH_COMBINED_RX_BUF
+	default BLUETOOTH_RX_BUF_LEN if BLUETOOTH_COMBINED_RX_BUF
 	depends on BLUETOOTH_RFCOMM
-	range BLUETOOTH_L2CAP_IN_MTU 32767
+	range BLUETOOTH_L2CAP_IN_MTU 32767 if !BLUETOOTH_COMBINED_RX_BUF
+	range BLUETOOTH_RX_BUF_LEN 32767 if BLUETOOTH_COMBINED_RX_BUF
 	help
 	  Maximum size of L2CAP PDU for RFCOMM frames.
 

subsys/bluetooth/host/hci_core.c

@@ -122,9 +122,15 @@ struct acl_data {
 NET_BUF_POOL_DEFINE(hci_cmd_pool, CONFIG_BLUETOOTH_HCI_CMD_COUNT,
 		    CMD_BUF_SIZE, sizeof(struct cmd_data), NULL);
 
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+NET_BUF_POOL_DEFINE(hci_rx_pool, CONFIG_BLUETOOTH_RX_BUF_COUNT,
+		    BT_BUF_RX_SIZE, BT_BUF_USER_DATA_MIN, NULL);
+#else
 /* HCI event buffers */
 NET_BUF_POOL_DEFINE(hci_evt_pool, CONFIG_BLUETOOTH_HCI_EVT_COUNT,
 		    BT_BUF_EVT_SIZE, BT_BUF_USER_DATA_MIN, NULL);
+#endif
+
 /*
  * This priority pool is to handle HCI events that must not be dropped
  * (currently this is Command Status, Command Complete and Number of
@@ -133,17 +139,23 @@ NET_BUF_POOL_DEFINE(hci_evt_pool, CONFIG_BLUETOOTH_HCI_EVT_COUNT,
  * the HCI ECC emulation is able to also allocate command status events
  * we need to reserve one extra buffer for it.
  */
+
+/* The worst case event length, Read Local Supported Commands Complete:
+ * 2 (HCI evt hdr) + 3 (cmd complete hdr) + 65 (parameters) = 70.
+ */
+#define PRIO_EVT_SIZE (CONFIG_BLUETOOTH_HCI_RECV_RESERVE + 70)
+
 #if defined(CONFIG_BLUETOOTH_TINYCRYPT_ECC)
-NET_BUF_POOL_DEFINE(hci_evt_prio_pool, 2, BT_BUF_EVT_SIZE,
+NET_BUF_POOL_DEFINE(hci_evt_prio_pool, 2, PRIO_EVT_SIZE,
 		    BT_BUF_USER_DATA_MIN, NULL);
 #else
-NET_BUF_POOL_DEFINE(hci_evt_prio_pool, 1, BT_BUF_EVT_SIZE,
+NET_BUF_POOL_DEFINE(hci_evt_prio_pool, 1, PRIO_EVT_SIZE,
 		    BT_BUF_USER_DATA_MIN, NULL);
 #endif
 
 static struct tc_hmac_prng_struct prng;
 
-#if defined(CONFIG_BLUETOOTH_CONN)
+#if defined(CONFIG_BLUETOOTH_HOST_FLOW_CONTROL)
 static void report_completed_packet(struct net_buf *buf)
 {
 
@@ -180,7 +192,12 @@ static void report_completed_packet(struct net_buf *buf)
 NET_BUF_POOL_DEFINE(acl_in_pool, CONFIG_BLUETOOTH_ACL_IN_COUNT,
 		    BT_BUF_ACL_IN_SIZE, sizeof(struct acl_data),
 		    report_completed_packet);
-#endif /* CONFIG_BLUETOOTH_CONN */
+#elif !defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF) && \
+	defined(CONFIG_BLUETOOTH_CONN)
+NET_BUF_POOL_DEFINE(acl_in_pool, CONFIG_BLUETOOTH_ACL_IN_COUNT,
+		    BT_BUF_ACL_IN_SIZE, sizeof(struct acl_data),
+		    NULL);
+#endif
 
 #if defined(CONFIG_BLUETOOTH_DEBUG)
 const char *bt_addr_str(const bt_addr_t *addr)
@@ -1009,7 +1026,9 @@ failed:
 	bt_conn_unref(conn);
 	bt_le_scan_update(false);
 }
+#endif /* CONFIG_BLUETOOTH_CONN */
 
+#if defined(CONFIG_BLUETOOTH_HOST_FLOW_CONTROL)
 static int set_flow_control(void)
 {
 	struct bt_hci_cp_host_buffer_size *hbs;
@@ -1047,7 +1066,7 @@ static int set_flow_control(void)
 	net_buf_add_u8(buf, BT_HCI_CTL_TO_HOST_FLOW_ENABLE);
 	return bt_hci_cmd_send_sync(BT_HCI_OP_SET_CTL_TO_HOST_FLOW, buf, NULL);
 }
-#endif /* CONFIG_BLUETOOTH_CONN */
+#endif /* CONFIG_BLUETOOTH_HOST_FLOW_CONTROL */
 
 #if defined(CONFIG_BLUETOOTH_BREDR)
 static void reset_pairing(struct bt_conn *conn)
@@ -2991,7 +3010,7 @@ static int common_init(void)
 	read_supported_commands_complete(rsp);
 	net_buf_unref(rsp);
 
-#if defined(CONFIG_BLUETOOTH_CONN)
+#if defined(CONFIG_BLUETOOTH_HOST_FLOW_CONTROL)
 	err = set_flow_control();
 	if (err) {
 		return err;
@@ -4029,7 +4048,11 @@ struct net_buf *bt_buf_get_evt(uint8_t opcode, int32_t timeout)
 		buf = net_buf_alloc(&hci_evt_prio_pool, timeout);
 		break;
 	default:
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+		buf = net_buf_alloc(&hci_rx_pool, K_NO_WAIT);
+#else
 		buf = net_buf_alloc(&hci_evt_pool, K_NO_WAIT);
+#endif
 		if (!buf && opcode == 0x00) {
 			buf = net_buf_alloc(&hci_evt_prio_pool, timeout);
 		}
@@ -4049,7 +4072,11 @@ struct net_buf *bt_buf_get_acl(int32_t timeout)
 #if defined(CONFIG_BLUETOOTH_CONN)
 	struct net_buf *buf;
 
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+	buf = net_buf_alloc(&hci_rx_pool, timeout);
+#else
 	buf = net_buf_alloc(&acl_in_pool, timeout);
+#endif
 	if (buf) {
 		net_buf_reserve(buf, CONFIG_BLUETOOTH_HCI_RECV_RESERVE);
 		bt_buf_set_type(buf, BT_BUF_ACL_IN);

subsys/bluetooth/host/hci_raw.c

@@ -29,6 +29,10 @@
 
 static struct k_fifo *raw_rx;
 
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+NET_BUF_POOL_DEFINE(hci_rx_pool, CONFIG_BLUETOOTH_RX_BUF_COUNT,
+		    BT_BUF_RX_SIZE, BT_BUF_USER_DATA_MIN, NULL);
+#else
 /* ACL incoming buffers */
 NET_BUF_POOL_DEFINE(acl_in_pool, CONFIG_BLUETOOTH_ACL_IN_COUNT,
 		    BT_BUF_ACL_IN_SIZE, sizeof(uint8_t), NULL);
@@ -36,6 +40,7 @@ NET_BUF_POOL_DEFINE(acl_in_pool, CONFIG_BLUETOOTH_ACL_IN_COUNT,
 /* HCI event buffers */
 NET_BUF_POOL_DEFINE(hci_evt_pool, CONFIG_BLUETOOTH_HCI_EVT_COUNT,
 		    BT_BUF_EVT_SIZE, sizeof(uint8_t), NULL);
+#endif
 
 struct bt_dev_raw bt_dev;
 
@@ -68,7 +73,11 @@ struct net_buf *bt_buf_get_evt(uint8_t opcode, int timeout)
 {
 	struct net_buf *buf;
 
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+	buf = net_buf_alloc(&hci_rx_pool, timeout);
+#else
 	buf = net_buf_alloc(&hci_evt_pool, timeout);
+#endif
 	if (buf) {
 		bt_buf_set_type(buf, BT_BUF_EVT);
 	}
@@ -80,7 +89,11 @@ struct net_buf *bt_buf_get_acl(int32_t timeout)
 {
 	struct net_buf *buf;
 
+#if defined(CONFIG_BLUETOOTH_COMBINED_RX_BUF)
+	buf = net_buf_alloc(&hci_rx_pool, timeout);
+#else
 	buf = net_buf_alloc(&acl_in_pool, timeout);
+#endif
 	if (buf) {
 		bt_buf_set_type(buf, BT_BUF_ACL_IN);
 	}