xref: /nrf52832-nimble/rt-thread/components/net/lwip-2.1.0/doc/ZeroCopyRx.c (revision 104654410c56c573564690304ae786df310c91fc)
1*10465441SEvalZero typedef struct my_custom_pbuf
2*10465441SEvalZero {
3*10465441SEvalZero    struct pbuf_custom p;
4*10465441SEvalZero    void* dma_descriptor;
5*10465441SEvalZero } my_custom_pbuf_t;
6*10465441SEvalZero 
7*10465441SEvalZero LWIP_MEMPOOL_DECLARE(RX_POOL, 10, sizeof(my_custom_pbuf_t), "Zero-copy RX PBUF pool");
8*10465441SEvalZero 
my_pbuf_free_custom(void * p)9*10465441SEvalZero void my_pbuf_free_custom(void* p)
10*10465441SEvalZero {
11*10465441SEvalZero   SYS_ARCH_DECL_PROTECT(old_level);
12*10465441SEvalZero 
13*10465441SEvalZero   my_custom_pbuf_t* my_puf = (my_custom_pbuf_t*)p;
14*10465441SEvalZero 
15*10465441SEvalZero   // invalidate data cache here - lwIP and/or application may have written into buffer!
16*10465441SEvalZero   // (invalidate is faster than flushing, and noone needs the correct data in the buffer)
17*10465441SEvalZero   invalidate_cpu_cache(p->payload, p->tot_len);
18*10465441SEvalZero 
19*10465441SEvalZero   SYS_ARCH_PROTECT(old_level);
20*10465441SEvalZero   free_rx_dma_descriptor(my_pbuf->dma_descriptor);
21*10465441SEvalZero   LWIP_MEMPOOL_FREE(RX_POOL, my_pbuf);
22*10465441SEvalZero   SYS_ARCH_UNPROTECT(old_level);
23*10465441SEvalZero }
24*10465441SEvalZero 
eth_rx_irq()25*10465441SEvalZero void eth_rx_irq()
26*10465441SEvalZero {
27*10465441SEvalZero   dma_descriptor*   dma_desc = get_RX_DMA_descriptor_from_ethernet();
28*10465441SEvalZero   my_custom_pbuf_t* my_pbuf  = (my_custom_pbuf_t*)LWIP_MEMPOOL_ALLOC(RX_POOL);
29*10465441SEvalZero 
30*10465441SEvalZero   my_pbuf->p.custom_free_function = my_pbuf_free_custom;
31*10465441SEvalZero   my_pbuf->dma_descriptor         = dma_desc;
32*10465441SEvalZero 
33*10465441SEvalZero   invalidate_cpu_cache(dma_desc->rx_data, dma_desc->rx_length);
34*10465441SEvalZero 
35*10465441SEvalZero   struct pbuf* p = pbuf_alloced_custom(PBUF_RAW,
36*10465441SEvalZero      dma_desc->rx_length,
37*10465441SEvalZero      PBUF_REF,
38*10465441SEvalZero      &my_pbuf->p,
39*10465441SEvalZero      dma_desc->rx_data,
40*10465441SEvalZero      dma_desc->max_buffer_size);
41*10465441SEvalZero 
42*10465441SEvalZero   if(netif->input(p, netif) != ERR_OK) {
43*10465441SEvalZero     pbuf_free(p);
44*10465441SEvalZero   }
45*10465441SEvalZero }
46