Function dma_alloc

components/drivers/dma/dma_pool.c:315–385

}

static void *dma_alloc(struct rt_device *dev, rt_size_t size,
        rt_ubase_t *dma_handle, rt_ubase_t flags)
{
    void *dma_buffer = RT_NULL;
    struct rt_dma_pool *pool;

    region_pool_lock();

    rt_list_for_each_entry(pool, &dma_pool_nodes, list)
    {
        if (pool->flags & RT_DMA_F_DEVICE)
        {
            if (!(flags & RT_DMA_F_DEVICE) || pool->dev != dev)
            {
                continue;
            }
        }
        else if ((flags & RT_DMA_F_DEVICE))
        {
            continue;
        }

        if ((flags & RT_DMA_F_NOMAP) && !((pool->flags & RT_DMA_F_NOMAP)))
        {
            continue;
        }

        if ((flags & RT_DMA_F_32BITS) && !((pool->flags & RT_DMA_F_32BITS)))
        {
            continue;
        }

        if ((flags & RT_DMA_F_LINEAR) && !((pool->flags & RT_DMA_F_LINEAR)))
        {
            continue;
        }

        *dma_handle = dma_pool_alloc(pool, size);

        if (*dma_handle && !(flags & RT_DMA_F_NOMAP))
        {
            if (flags & RT_DMA_F_NOCACHE)
            {
                dma_buffer = rt_ioremap_nocache((void *)*dma_handle, size);
            }
            else
            {
                dma_buffer = rt_ioremap_cached((void *)*dma_handle, size);
            }

            if (!dma_buffer)
            {
                dma_pool_free(pool, *dma_handle, size);

                continue;
            }

            break;