[mbed-tls] Mbedtls Client Key Exchange Time

Hello, I'm using mbedTLS on baremetal lwip+stm32f4 system as a Server. TLS working successfully with the TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 but when I receive the Client Hello message than my receive proccess function in ethernetif_input: err = netif->input(p, netif); takes 300ms time. This function normaly takes 1ms. I need to reduce this time. How Can I do that ? This is my config file: https://paste.ofcode.org/Bdt4FapskKY7M5ggm3uViJ

Best Regards.