source: ReferenceDesigns/w3_802.11/c/wlan_w3_high/w3_eth.c

#include "wlan_mac_high_sw_config.h"

#include "wlan_platform_high.h"
#include "include/w3_high.h"
#include "include/w3_eth.h"
#include "xparameters.h"
#include "xintc.h"
#include "wlan_exp_node.h"
#include "wlan_platform_common.h"
#include "wlan_platform_high.h"
#include "wlan_mac_common.h"
#include "wlan_mac_dl_list.h"
#include "wlan_mac_high.h"
#include "wlan_mac_eth_util.h"
#include "wlan_mac_schedule.h"
#include "wlan_mac_queue.h"
#include "wlan_mac_802_11_defs.h"
#include "wlan_axi_ethernet_intr.h"

#include "xaxidma.h"

#if WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE
static XAxiDma portal_eth_dma_instance;
peripheral_args_t portal_peripheral_args;
#endif

#if WLAN_SW_CONFIG_ENABLE_WLAN_EXP
static XAxiDma wlan_exp_eth_dma_instance;
peripheral_args_t wlan_exp_peripheral_args;
#endif



// Local Function Declarations -- these are not intended to be called by functions outside of this file
#if (WLAN_SW_CONFIG_ENABLE_WLAN_EXP || WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE)
void _eth_send_done( eth_tx_queue_buffer_t* eth_tx_queue_buffer );
#endif

/*****************************************************************************/
/**
 * @brief Transmits a packet over Ethernet (Portal)
 *
 * This function transmits a single packet via Ethernet using the axi_dma. The
 * packet passed via pkt_ptr must be a valid Ethernet packet, complete with
 * 14-byte Ethernet header. This function does not check for a valid header
 * (i.e. the calling function must ensure this).
 *
 * The packet must be stored in a memory location accessible by the axi_dma core.
 * The MicroBlaze DLMB is *not* accessible to the DMA. Thus packets cannot be
 * stored in malloc'd areas (the heap is in the DLMB).  In the reference implementation
 * all Ethernet transmissions start as wireless receptions. Thus, the Ethernet payloads
 * are stored in the wireless Rx packet buffer, which is accessible by the DMA.
 *
 * Custom code which needs to send Ethernet packets can use a spare wireless Tx/Rx
 * packet buffer, a spare Tx queue entry in DRAM or the user scratch space in DRAM
 * to create custom Ethernet payloads.
 *
 * This function blocks until the Ethernet transmission completes.
 *
 * @param eth_tx_queue_buffer_t* eth_tx_queue_buffer - Queue buffer describing to-be-sent packet
 *
 * @return 0 for successful Ethernet transmission, -1 otherwise
 */
#if WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE
int wlan_platform_portal_eth_send( eth_tx_queue_buffer_t* eth_tx_queue_buffer ) {
    int status;

    // IMPORTANT:  If the data cache is enabled the cache must be flushed before
    // attempting to send a packet via the ETH DMA. The DMA will read packet
    // contents directly from RAM, bypassing any cache checking normally done by
    // the MicroBlaze.  The data cache is disabled by default in the reference
    // implementation.
    //
    // Xil_DCacheFlushRange((u32)TxPacket, MAX_PKT_LEN);


    status = wlan_axi_eth_intr_send( &portal_peripheral_args, eth_tx_queue_buffer );

    if(status & WLAN_AXI_ETH_INTR_SEND_ERR_NO_FREE_BD){
        return WLAN_FAILURE;
    } else {
        return WLAN_SUCCESS;
    }
}

int wlan_platform_portal_eth_get_mtu(){
    return wlan_axi_eth_intr_get_mtu();
}
#endif //WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE

#if WLAN_SW_CONFIG_ENABLE_WLAN_EXP
int wlan_platform_wlan_exp_eth_send( eth_tx_queue_buffer_t* eth_tx_queue_buffer ) {
    int status;
    status = wlan_axi_eth_intr_send( &wlan_exp_peripheral_args, eth_tx_queue_buffer );

    if(status & WLAN_AXI_ETH_INTR_SEND_ERR_NO_FREE_BD){
        return WLAN_FAILURE;
    } else {
        return WLAN_SUCCESS;
    }
}
int wlan_platform_wlan_exp_eth_get_mtu(){
    return wlan_axi_eth_intr_get_mtu();
}
#endif

int w3_wlan_platform_ethernet_init() {

#if WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE || WLAN_SW_CONFIG_ENABLE_WLAN_EXP
    intr_conn_params_t intr_conn_params;
    int status;
#endif

#if WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE || (WLAN_SW_CONFIG_ENABLE_WLAN_EXP && (ETH_WLAN_EXP == 0))
    // FIXME: I'm not currently working on the single-Ethernet design, but when I do,
    //        I need to trace through the implications of WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE = 0
    //        and (WLAN_SW_CONFIG_ENABLE_WLAN_EXP = 1, ETH_WLAN_EXP = 0)

    portal_peripheral_args.driver_instance = (void*)&portal_eth_dma_instance;
    portal_peripheral_args.callback0 = (void*)wlan_enqueue_eth_rx;
    portal_peripheral_args.callback1 = (void*)_eth_send_done;

    // Set up ETH A
    intr_conn_params = wlan_axi_eth_intr_init(&portal_peripheral_args,
                                              PORTAL_ETH_DEV_ID,
                                              PORTAL_ETH_LINK_SPEED,
                                              PORTAL_ETH_MDIO_PHYADDR,
                                              PORTAL_ETH_BD_MEM_BASEADDR,
                                              PORTAL_ETH_BD_MEM_SIZE,
                                              2,
                                              1,
                                              0);

    if(intr_conn_params.intr_handler0 == NULL){
        return WLAN_FAILURE;
    }

    // Connect the peripheral to the interrupt controller
    status = wlan_platform_interrupt_connect(PORTAL_ETH_RX_INTR_ID, (wlan_intr_handler_t)intr_conn_params.intr_handler0, intr_conn_params.intr_handler_arg0);

    if (status != WLAN_SUCCESS) {
        xil_printf("ERROR: Failed to connect axi_dma interrupt: (%d)\n", status);
        return WLAN_FAILURE;
    }

    if(intr_conn_params.intr_handler0 == NULL){
        return WLAN_FAILURE;
    }

    // Connect the peripheral to the interrupt controller
    status = wlan_platform_interrupt_connect(PORTAL_ETH_TX_INTR_ID, (wlan_intr_handler_t)intr_conn_params.intr_handler1, intr_conn_params.intr_handler_arg1);

    if (status != WLAN_SUCCESS) {
        xil_printf("ERROR: Failed to connect axi_dma interrupt: (%d)\n", status);
        return WLAN_FAILURE;
    }

    wlan_platform_interrupt_enable(PORTAL_ETH_RX_INTR_ID);
    wlan_platform_interrupt_enable(PORTAL_ETH_TX_INTR_ID);
#endif

#if WLAN_SW_CONFIG_ENABLE_WLAN_EXP && (ETH_WLAN_EXP == 1)
    // Set up ETH B
    wlan_exp_peripheral_args.driver_instance = (void*)&wlan_exp_eth_dma_instance;
    wlan_exp_peripheral_args.callback0 = (void*)wlan_exp_process_eth_rx;
    wlan_exp_peripheral_args.callback1 = (void*)_eth_send_done;

    // Some notes about the heuristics embedded in the following parameters:
    // - 12 Tx BDs -- this will support a maximum of 6 packets during log retrieval (which uses 2 BDs per packet)
    // - 3 Tx Coalescing -- in a backlogged scenario, we'll wait for 3 transmissions to be complete. In log retrieval, we'll
    //   split out ring of 6 packets into 2 chunks and process Tx done interrupts one chunk at a time
    // - 154 timer delay -- in this hardware platform, C_DLYTMR_RESOLUTION is 125 and m_axi_sg_aclk is 160 Mhz.
    //   The unit of this parameter is therefore an integer number of 125/160 usec (or 781 ns). Conservatively, assume that C
    //   can sustain 100Mbps of Tx throughput with standard MTUs. This is equivalent to a 1500 byte packet every 120 usec.
    //   If more than 120 usec elapses after the last Tx done completion, we know we aren't currently attempting to backlog
    //   transmissions so we should just fire off an interrupt and not wait for coalescing. 120 usec is 154 delay units.
    intr_conn_params = wlan_axi_eth_intr_init(&wlan_exp_peripheral_args,
                                              WLAN_EXP_ETH_DEV_ID,
                                              WLAN_EXP_ETH_LINK_SPEED,
                                              WLAN_EXP_ETH_MDIO_PHYADDR,
                                              WLAN_EXP_ETH_BD_MEM_BASEADDR,
                                              WLAN_EXP_ETH_BD_MEM_SIZE,
                                              12,
                                              3,
                                              154);

    if(intr_conn_params.intr_handler0 == NULL){
        return WLAN_FAILURE;
    }

    // Connect the peripheral to the interrupt controller
    status = wlan_platform_interrupt_connect(WLAN_EXP_ETH_RX_INTR_ID, (wlan_intr_handler_t)intr_conn_params.intr_handler0, intr_conn_params.intr_handler_arg0);

    if (status != XST_SUCCESS) {
        xil_printf("ERROR: Failed to connect axi_dma interrupt: (%d)\n", status);
        return XST_FAILURE;
    }

    if(intr_conn_params.intr_handler1 == NULL){
        return WLAN_FAILURE;
    }
    // Connect the peripheral to the interrupt controller
    status = wlan_platform_interrupt_connect(WLAN_EXP_ETH_TX_INTR_ID, (wlan_intr_handler_t)intr_conn_params.intr_handler1, intr_conn_params.intr_handler_arg1);

    if (status != XST_SUCCESS) {
        xil_printf("ERROR: Failed to connect axi_dma interrupt: (%d)\n", status);
        return XST_FAILURE;
    }

    wlan_platform_interrupt_enable(WLAN_EXP_ETH_RX_INTR_ID);
    wlan_platform_interrupt_enable(WLAN_EXP_ETH_TX_INTR_ID);
#endif //WLAN_SW_CONFIG_ENABLE_WLAN_EXP

    return WLAN_SUCCESS;
}

void w3_wlan_platform_ethernet_free_queue_entry_notify(){
    // We need to disable interrupts here if this function was called from a non-ISR context. Otherwise,
    // we may get called again and interrupt ourselves from an ISR context while manipulating BDs.
    interrupt_state_t prev_interrupt_state = wlan_platform_intc_stop();
#if WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE
    wlan_axi_eth_intr_attach_free_rx_bd(&portal_peripheral_args);
#endif

#if WLAN_SW_CONFIG_ENABLE_WLAN_EXP
    wlan_axi_eth_intr_attach_free_rx_bd(&wlan_exp_peripheral_args);
#endif //WLAN_SW_CONFIG_ENABLE_WLAN_EXP
    wlan_platform_intc_set_state(prev_interrupt_state);

}

#if WLAN_SW_CONFIG_ENABLE_ETH_BRIDGE || WLAN_SW_CONFIG_ENABLE_WLAN_EXP
void _eth_send_done( eth_tx_queue_buffer_t* eth_tx_queue_buffer ){
    wlan_mac_high_cdma_finish_transfer();

    // Free the just-sent Tx queue buffer
    if(eth_tx_queue_buffer != NULL) queue_checkin(eth_tx_queue_buffer->pyld_queue_hdr.dle);
}
#endif