Altera TSE driver and example program for lwIP (1.3.2)

Well basically I need to move received data to DMA or vice-versa.

I've made such set up: Packet formation in logic (incl. IP checksum) -> SGDMA -> InterNiche.

However, when I set up all the packet data in SGDMA interrupt, e.g. packet allocation in memory, reading from the dma memory, etc, the interrupt lasts so long, that 3.5mbps packet data is too fast. My data must go between 10-80mbps. The solution would be to write exactly to InterNiche packet buffer using DMA, but then I need to know where InterNiche place the buffer (which I suppose is just malloc/free stuff). Another problem is that I need to do packet allocation on every interrupt and I don't know why InterNiche does packet freeing or other internal stuff.

The packet is sent using ip_write().

I would like to test LwIP for its performance in this case, or maybe someone has pointers for my InterNiche setup?