buf.h

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/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_
#define ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_

 
#include <stddef.h>
#include <stdint.h>
 
#include <zephyr/autoconf.h>
#include <zephyr/bluetooth/hci.h>
#include <zephyr/bluetooth/hci_types.h>
#include <zephyr/net_buf.h>
#include <zephyr/sys/util.h>
#include <zephyr/sys/util_macro.h>
#include <zephyr/sys/clock.h>
#include <zephyr/toolchain.h>
 
#ifdef __cplusplus
extern "C" {
#endif

enum bt_buf_type {
        BT_BUF_TYPE_NONE = 0,
        BT_BUF_CMD = BIT(0),
        BT_BUF_EVT = BIT(1),
        BT_BUF_ACL_OUT = BIT(2),
        BT_BUF_ACL_IN = BIT(3),
        BT_BUF_ISO_OUT = BIT(4),
        BT_BUF_ISO_IN = BIT(5),
};

enum bt_buf_dir {
        BT_BUF_IN,
        BT_BUF_OUT,
};

static inline uint8_t bt_buf_type_to_h4(enum bt_buf_type type)
{
        switch (type) {
        case BT_BUF_CMD:
                return BT_HCI_H4_CMD;
        case BT_BUF_ACL_IN:
        case BT_BUF_ACL_OUT:
                return BT_HCI_H4_ACL;
        case BT_BUF_ISO_IN:
        case BT_BUF_ISO_OUT:
                return BT_HCI_H4_ISO;
        case BT_BUF_EVT:
                return BT_HCI_H4_EVT;
        default:
                __ASSERT_NO_MSG(false);
                return 0;
        }
}

static inline enum bt_buf_type bt_buf_type_from_h4(uint8_t h4_type, enum bt_buf_dir dir)
{
        switch (h4_type) {
        case BT_HCI_H4_CMD:
                return BT_BUF_CMD;
        case BT_HCI_H4_ACL:
                return dir == BT_BUF_OUT ? BT_BUF_ACL_OUT : BT_BUF_ACL_IN;
        case BT_HCI_H4_EVT:
                return BT_BUF_EVT;
        case BT_HCI_H4_ISO:
                return dir == BT_BUF_OUT ? BT_BUF_ISO_OUT : BT_BUF_ISO_IN;
        default:
                return BT_BUF_TYPE_NONE;
        }
}
 
/* Headroom reserved in buffers, primarily for HCI transport encoding purposes */
#define BT_BUF_RESERVE 1

#define BT_BUF_SIZE(size) (BT_BUF_RESERVE + (size))

#define BT_BUF_ACL_SIZE(size) BT_BUF_SIZE(BT_HCI_ACL_HDR_SIZE + (size))

#define BT_BUF_EVT_SIZE(size) BT_BUF_SIZE(BT_HCI_EVT_HDR_SIZE + (size))

#define BT_BUF_CMD_SIZE(size) BT_BUF_SIZE(BT_HCI_CMD_HDR_SIZE + (size))

#define BT_BUF_ISO_SIZE(size) BT_BUF_SIZE(BT_HCI_ISO_HDR_SIZE + \
                                          BT_HCI_ISO_SDU_TS_HDR_SIZE + \
                                          (size))

#define BT_BUF_ACL_RX_SIZE BT_BUF_ACL_SIZE(CONFIG_BT_BUF_ACL_RX_SIZE)

#define BT_BUF_EVT_RX_SIZE BT_BUF_EVT_SIZE(CONFIG_BT_BUF_EVT_RX_SIZE)
 
#if defined(CONFIG_BT_ISO)
#define BT_BUF_ISO_RX_SIZE BT_BUF_ISO_SIZE(CONFIG_BT_ISO_RX_MTU)
#define BT_BUF_ISO_RX_COUNT CONFIG_BT_ISO_RX_BUF_COUNT
#else
#define BT_BUF_ISO_RX_SIZE 0
#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.
 */
#define BT_BUF_ACL_RX_COUNT_EXTRA CONFIG_BT_BUF_ACL_RX_COUNT_EXTRA
#define 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 */
 
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");

#define BT_BUF_RX_SIZE (MAX(MAX(BT_BUF_ACL_RX_SIZE, BT_BUF_EVT_RX_SIZE), \
                            BT_BUF_ISO_RX_SIZE))
 
/* 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");

#define BT_BUF_RX_COUNT (CONFIG_BT_BUF_EVT_RX_COUNT + \
                         MAX(BT_BUF_ACL_RX_COUNT, BT_BUF_ISO_RX_COUNT))

#define BT_BUF_CMD_TX_SIZE BT_BUF_CMD_SIZE(CONFIG_BT_BUF_CMD_TX_SIZE)

struct net_buf *bt_buf_get_rx(enum bt_buf_type type, k_timeout_t timeout);

typedef void (*bt_buf_rx_freed_cb_t)(enum bt_buf_type type_mask);

void bt_buf_rx_freed_cb_set(bt_buf_rx_freed_cb_t cb);

struct net_buf *bt_buf_get_tx(enum bt_buf_type type, k_timeout_t timeout,
                              const void *data, size_t size);

struct net_buf *bt_buf_get_evt(uint8_t evt, bool discardable, k_timeout_t timeout);

 
#ifdef __cplusplus
}
#endif
 
#endif /* ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_ */