udc_buf.h

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/*
 * Copyright (c) 2024 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_UDC_BUF_H
#define ZEPHYR_INCLUDE_UDC_BUF_H
 
#include <zephyr/kernel.h>
#include <zephyr/net_buf.h>
 
#if defined(CONFIG_DCACHE) && !defined(CONFIG_UDC_BUF_FORCE_NOCACHE)
/*
 * Here we try to get DMA-safe buffers, but we lack a consistent source of
 * information about data cache properties, such as line cache size, and a
 * consistent source of information about what part of memory is DMA'able.
 * For now, we simply assume that all available memory is DMA'able and use
 * Kconfig option DCACHE_LINE_SIZE for alignment and granularity.
 */
#define Z_UDC_BUF_ALIGN         CONFIG_DCACHE_LINE_SIZE
#define Z_UDC_BUF_GRANULARITY   CONFIG_DCACHE_LINE_SIZE
#else
/*
 * Default alignment and granularity to pointer size if the platform does not
 * have a data cache or buffers are placed in nocache memory region.
 */
#define Z_UDC_BUF_ALIGN         sizeof(void *)
#define Z_UDC_BUF_GRANULARITY   sizeof(void *)
#endif
 
 
#if defined(CONFIG_UDC_BUF_FORCE_NOCACHE)
/*
 * The usb transfer buffer needs to be in __nocache section
 */
#define Z_UDC_BUF_SECTION       __nocache
#else
#define Z_UDC_BUF_SECTION
#endif
 
#define UDC_BUF_ALIGN           Z_UDC_BUF_ALIGN
 
#define UDC_BUF_GRANULARITY     Z_UDC_BUF_GRANULARITY
 
#define UDC_STATIC_BUF_DEFINE(name, size)                                       \
        static uint8_t Z_UDC_BUF_SECTION __aligned(UDC_BUF_ALIGN)               \
        name[ROUND_UP(size, UDC_BUF_GRANULARITY)];
 
#define IS_UDC_ALIGNED(buf) IS_ALIGNED(buf, UDC_BUF_ALIGN)
 
#define UDC_HEAP_DEFINE(name, bytes, in_section)                                \
        uint8_t in_section __aligned(UDC_BUF_ALIGN)                             \
                kheap_##name[MAX(bytes, Z_HEAP_MIN_SIZE)];                      \
        STRUCT_SECTION_ITERABLE(k_heap, name) = {                               \
                .heap = {                                                       \
                        .init_mem = kheap_##name,                               \
                        .init_bytes = MAX(bytes, Z_HEAP_MIN_SIZE),              \
                 },                                                             \
        }
 
#define UDC_K_HEAP_DEFINE(name, size)                                           \
        COND_CODE_1(CONFIG_UDC_BUF_FORCE_NOCACHE,                               \
                    (UDC_HEAP_DEFINE(name, size, __nocache)),                   \
                    (UDC_HEAP_DEFINE(name, size, __noinit)))
 
extern const struct net_buf_data_cb net_buf_dma_cb;
#define UDC_BUF_POOL_VAR_DEFINE(pname, count, size, ud_size, fdestroy)          \
        _NET_BUF_ARRAY_DEFINE(pname, count, ud_size);                           \
        UDC_K_HEAP_DEFINE(net_buf_mem_pool_##pname, size);                      \
        static const struct net_buf_data_alloc net_buf_data_alloc_##pname = {   \
                .cb = &net_buf_dma_cb,                                          \
                .alloc_data = &net_buf_mem_pool_##pname,                        \
                .max_alloc_size = 0,                                            \
        };                                                                      \
        static STRUCT_SECTION_ITERABLE(net_buf_pool, pname) =                   \
                NET_BUF_POOL_INITIALIZER(pname, &net_buf_data_alloc_##pname,    \
                                         _net_buf_##pname, count, ud_size,      \
                                         fdestroy)
 
#define UDC_BUF_POOL_DEFINE(pname, count, size, ud_size, fdestroy)              \
        _NET_BUF_ARRAY_DEFINE(pname, count, ud_size);                           \
        BUILD_ASSERT((UDC_BUF_GRANULARITY) % (UDC_BUF_ALIGN) == 0,              \
                     "Code assumes granurality is multiple of alignment");      \
        static uint8_t Z_UDC_BUF_SECTION __aligned(UDC_BUF_ALIGN)               \
                net_buf_data_##pname[count][ROUND_UP(size, UDC_BUF_GRANULARITY)];\
        static const struct net_buf_pool_fixed net_buf_fixed_##pname = {        \
                .data_pool = (uint8_t *)net_buf_data_##pname,                   \
        };                                                                      \
        static const struct net_buf_data_alloc net_buf_fixed_alloc_##pname = {  \
                .cb = &net_buf_fixed_cb,                                        \
                .alloc_data = (void *)&net_buf_fixed_##pname,                   \
                .max_alloc_size = ROUND_UP(size, UDC_BUF_GRANULARITY),          \
        };                                                                      \
        static STRUCT_SECTION_ITERABLE(net_buf_pool, pname) =                   \
                NET_BUF_POOL_INITIALIZER(pname, &net_buf_fixed_alloc_##pname,   \
                                         _net_buf_##pname, count, ud_size,      \
                                         fdestroy)
 
#endif /* ZEPHYR_INCLUDE_UDC_BUF_H */