Bluetooth: nRF Connect SDK v2.6.4 NCSIDB-1718 cherry-picks

doc/releases/migration-guide-3.6.rst

@@ -122,6 +122,10 @@ Bluetooth
   Any pointer to a UUID must be prefixed with `const`, otherwise there will be a compilation warning.
   For example change ``struct bt_uuid *uuid = BT_UUID_DECLARE_16(xx)`` to
   ``const struct bt_uuid *uuid = BT_UUID_DECLARE_16(xx)``. (:github:`66136`)
+* The :c:func:`bt_l2cap_chan_send` API no longer allocates buffers from the same pool as its `buf`
+  parameter when segmenting SDUs into PDUs. In order to reproduce the previous behavior, the
+  application should register the `alloc_seg` channel callback and allocate from the same pool as
+  `buf`.
 
 * Mesh
 

include/zephyr/bluetooth/buf.h

@@ -88,14 +88,47 @@ struct bt_buf_data {
 #define BT_BUF_ISO_RX_COUNT 0
 #endif /* CONFIG_BT_ISO */
 
+/* see Core Spec v6.0 vol.4 part E 7.4.5 */
+#define BT_BUF_ACL_RX_COUNT_MAX 65535
+
+#if defined(CONFIG_BT_CONN) && defined(CONFIG_BT_HCI_HOST)
+ /* The host needs more ACL buffers than maximum ACL links. This is because of
+  * the way we re-assemble ACL packets into L2CAP PDUs.
+  *
+  * We keep around the first buffer (that comes from the driver) to do
+  * re-assembly into, and if all links are re-assembling, there will be no buffer
+  * available for the HCI driver to allocate from.
+  *
+  * TODO: When CONFIG_BT_BUF_ACL_RX_COUNT is removed,
+  *       remove the MAX and only keep the 1.
+  */
+#define BT_BUF_ACL_RX_COUNT_EXTRA CONFIG_BT_BUF_ACL_RX_COUNT_EXTRA
+#define BT_BUF_ACL_RX_COUNT       (MAX(CONFIG_BT_BUF_ACL_RX_COUNT, 1) + BT_BUF_ACL_RX_COUNT_EXTRA)
+#else
+#define BT_BUF_ACL_RX_COUNT_EXTRA 0
+#define BT_BUF_ACL_RX_COUNT       0
+#endif /* CONFIG_BT_CONN && CONFIG_BT_HCI_HOST */
+
+#if defined(CONFIG_BT_BUF_ACL_RX_COUNT) && CONFIG_BT_BUF_ACL_RX_COUNT > 0
+#warning "CONFIG_BT_BUF_ACL_RX_COUNT is deprecated, see Zephyr 4.1 migration guide"
+#endif /* CONFIG_BT_BUF_ACL_RX_COUNT && CONFIG_BT_BUF_ACL_RX_COUNT > 0 */
+
+BUILD_ASSERT(BT_BUF_ACL_RX_COUNT <= BT_BUF_ACL_RX_COUNT_MAX,
+	     "Maximum number of ACL RX buffer is 65535, reduce CONFIG_BT_BUF_ACL_RX_COUNT_EXTRA");
+
 /** Data size needed for HCI ACL, HCI ISO or Event RX buffers */
 #define BT_BUF_RX_SIZE (MAX(MAX(BT_BUF_ACL_RX_SIZE, BT_BUF_EVT_RX_SIZE), \
 			    BT_BUF_ISO_RX_SIZE))
 
-/** Buffer count needed for HCI ACL, HCI ISO or Event RX buffers */
-#define BT_BUF_RX_COUNT (MAX(MAX(CONFIG_BT_BUF_EVT_RX_COUNT, \
-				 CONFIG_BT_BUF_ACL_RX_COUNT), \
-			     BT_BUF_ISO_RX_COUNT))
+/* Controller can generate up to CONFIG_BT_BUF_ACL_TX_COUNT number of unique HCI Number of Completed
+ * Packets events.
+ */
+BUILD_ASSERT(CONFIG_BT_BUF_EVT_RX_COUNT > CONFIG_BT_BUF_ACL_TX_COUNT,
+	     "Increase Event RX buffer count to be greater than ACL TX buffer count");
+
+/** Buffer count needed for HCI ACL or HCI ISO plus Event RX buffers */
+#define BT_BUF_RX_COUNT (CONFIG_BT_BUF_EVT_RX_COUNT + \
+			 MAX(BT_BUF_ACL_RX_COUNT, BT_BUF_ISO_RX_COUNT))
 
 /** Data size needed for HCI Command buffers. */
 #define BT_BUF_CMD_TX_SIZE BT_BUF_CMD_SIZE(CONFIG_BT_BUF_CMD_TX_SIZE)
@@ -113,6 +146,27 @@ struct bt_buf_data {
  */
 struct net_buf *bt_buf_get_rx(enum bt_buf_type type, k_timeout_t timeout);
 
+/** A callback to notify about freed buffer in the incoming data pool.
+ *
+ * This callback is called when a buffer of a given type is freed and can be requested through the
+ * @ref bt_buf_get_rx function. However, this callback is called from the context of the buffer
+ * freeing operation and must not attempt to allocate a new buffer from the same pool.
+ *
+ * @warning When this callback is called, the scheduler is locked and the callee must not perform
+ * any action that makes the current thread unready. This callback must only be used for very
+ * short non-blocking operation (e.g. submitting a work item).
+ *
+ * @param type_mask A bit mask of buffer types that have been freed.
+ */
+typedef void (*bt_buf_rx_freed_cb_t)(enum bt_buf_type type_mask);
+
+/** Set the callback to notify about freed buffer in the incoming data pool.
+ *
+ * @param cb Callback to notify about freed buffer in the incoming data pool. If NULL, the callback
+ *           is disabled.
+ */
+void bt_buf_rx_freed_cb_set(bt_buf_rx_freed_cb_t cb);
+
 /** Allocate a buffer for outgoing data
  *
  *  This will set the buffer type so bt_buf_set_type() does not need to
@@ -129,17 +183,6 @@ struct net_buf *bt_buf_get_rx(enum bt_buf_type type, k_timeout_t timeout);
 struct net_buf *bt_buf_get_tx(enum bt_buf_type type, k_timeout_t timeout,
 			      const void *data, size_t size);
 
-/** Allocate a buffer for an HCI Command Complete/Status Event
- *
- *  This will set the buffer type so bt_buf_set_type() does not need to
- *  be explicitly called before bt_recv_prio().
- *
- *  @param timeout Non-negative waiting period to obtain a buffer or one of the
- *                 special values K_NO_WAIT and K_FOREVER.
- *  @return A new buffer.
- */
-struct net_buf *bt_buf_get_cmd_complete(k_timeout_t timeout);
-
 /** Allocate a buffer for an HCI Event
  *
  *  This will set the buffer type so bt_buf_set_type() does not need to

include/zephyr/bluetooth/l2cap.h

@@ -585,9 +585,10 @@ int bt_l2cap_chan_disconnect(struct bt_l2cap_chan *chan);
  *  If the application is reserving the bytes it should use the
  *  BT_L2CAP_BUF_SIZE() helper to correctly size the buffers for the for the
  *  outgoing buffer pool.
- *  When segmenting an L2CAP SDU into L2CAP PDUs the stack will first attempt
- *  to allocate buffers from the original buffer pool of the L2CAP SDU before
- *  using the stacks own buffer pool.
+ *  When segmenting an L2CAP SDU into L2CAP PDUs the stack will first attempt to
+ *  allocate buffers from the channel's `alloc_seg` callback and will fallback
+ *  on the stack's global buffer pool (sized
+ *  @kconfig{CONFIG_BT_L2CAP_TX_BUF_COUNT}).
  *
  *  @note Buffer ownership is transferred to the stack in case of success, in
  *  case of an error the caller retains the ownership of the buffer.