libethdrivers/src/plat/zynq7000/zynq7000.c - 3p/sel4/util_libs - Git at Google

 /*
  * Copyright 2017, DornerWorks, Ltd.
  * Copyright 2017, Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: GPL-2.0-only
  */

 #include "unimplemented.h"
 #include "io.h"
 #include <platsupport/driver_module.h>
 #include <platsupport/fdt.h>
 #include <ethdrivers/gen_config.h>
 #include <ethdrivers/zynq7000.h>
 #include <ethdrivers/raw.h>
 #include <ethdrivers/helpers.h>
 #include <string.h>
 #include <utils/util.h>
 #include "zynq_gem.h"
 #include "uboot/net.h"
 #include "uboot/miiphy.h"
 #include "uboot/phy.h"
 #include <stdio.h>

 #define BUF_SIZE MAX_PKT_SIZE

 struct zynq7000_eth_data {
     struct eth_device *eth_dev;
     uintptr_t tx_ring_phys;
     uintptr_t rx_ring_phys;
     volatile struct emac_bd *tx_ring;
     volatile struct emac_bd *rx_ring;
     unsigned int rx_size;
     unsigned int tx_size;
     void **rx_cookies;
     unsigned int rx_remain;
     unsigned int tx_remain;
     void **tx_cookies;
     unsigned int *tx_lengths;
     /* track where the head and tail of the queues are for
      * enqueueing buffers / checking for completions */
     unsigned int rdt, rdh, tdt, tdh;
 };

 static void free_desc_ring(struct zynq7000_eth_data *dev, ps_dma_man_t *dma_man)
 {

     if (dev->rx_ring != NULL) {
         dma_unpin_free(dma_man, (void *)dev->rx_ring, sizeof(struct emac_bd) * dev->rx_size);
         dev->rx_ring = NULL;
     }

     if (dev->tx_ring != NULL) {
         dma_unpin_free(dma_man, (void *)dev->tx_ring, sizeof(struct emac_bd) * dev->tx_size);
         dev->tx_ring = NULL;
     }

     if (dev->rx_cookies != NULL) {
         free(dev->rx_cookies);
         dev->rx_cookies = NULL;
     }

     if (dev->tx_cookies != NULL) {
         free(dev->tx_cookies);
         dev->tx_cookies = NULL;
     }

     if (dev->tx_lengths != NULL) {
         free(dev->tx_lengths);
         dev->tx_lengths = NULL;
     }
 }

 static int initialize_desc_ring(struct zynq7000_eth_data *dev, ps_dma_man_t *dma_man)
 {
     dma_addr_t rx_ring = dma_alloc_pin(dma_man, sizeof(struct emac_bd) * dev->rx_size, 0, ARCH_DMA_MINALIGN);
     if (!rx_ring.phys) {
         LOG_ERROR("Failed to allocate rx_ring");
         return -1;
     }

     dev->rx_ring = rx_ring.virt;
     dev->rx_ring_phys = rx_ring.phys;
     dma_addr_t tx_ring = dma_alloc_pin(dma_man, sizeof(struct emac_bd) * dev->tx_size, 0, ARCH_DMA_MINALIGN);
     if (!tx_ring.phys) {
         LOG_ERROR("Failed to allocate tx_ring");
         free_desc_ring(dev, dma_man);
         return -1;
     }

     ps_dma_cache_clean_invalidate(dma_man, rx_ring.virt, sizeof(struct emac_bd) * dev->rx_size);
     ps_dma_cache_clean_invalidate(dma_man, tx_ring.virt, sizeof(struct emac_bd) * dev->tx_size);

     dev->rx_cookies = malloc(sizeof(void *) * dev->rx_size);
     dev->tx_cookies = malloc(sizeof(void *) * dev->tx_size);
     dev->tx_lengths = malloc(sizeof(unsigned int) * dev->tx_size);

     if (dev->rx_cookies == NULL || dev->tx_cookies == NULL || dev->tx_lengths == NULL) {

         if (dev->rx_cookies != NULL) {
             free(dev->rx_cookies);
         }

         if (dev->tx_cookies != NULL) {
             free(dev->tx_cookies);
         }

         if (dev->tx_lengths != NULL) {
             free(dev->tx_lengths);
         }

         LOG_ERROR("Failed to malloc");
         free_desc_ring(dev, dma_man);
         return -1;
     }

     dev->tx_ring = tx_ring.virt;
     dev->tx_ring_phys = tx_ring.phys;

     /* Remaining needs to be 2 less than size as we cannot actually enqueue size many descriptors,
      * since then the head and tail pointers would be equal, indicating empty. */
     dev->rx_remain = dev->rx_size - 2;
     dev->tx_remain = dev->tx_size - 2;

     dev->rdt = dev->rdh = dev->tdt = dev->tdh = 0;

     /* initialise both rings */
     for (unsigned int i = 0; i < dev->tx_size; i++) {
         dev->tx_ring[i] = (struct emac_bd) {
             .addr = 0,
             .status = ZYNQ_GEM_TXBUF_USED_MASK
         };
     }

     dev->tx_ring[dev->tx_size - 1].status |= ZYNQ_GEM_TXBUF_WRAP_MASK;

     for (unsigned int i = 0; i < dev->rx_size; i++) {
         dev->rx_ring[i] = (struct emac_bd) {
             .addr = ZYNQ_GEM_RXBUF_NEW_MASK,
             .status = 0
         };
     }

     dev->rx_ring[dev->rx_size - 1].addr |= ZYNQ_GEM_RXBUF_WRAP_MASK;

     __sync_synchronize();

     return 0;
 }

 static void fill_rx_bufs(struct eth_driver *driver)
 {

     struct zynq7000_eth_data *dev = (struct zynq7000_eth_data *)driver->eth_data;
     __sync_synchronize();

     while (dev->rx_remain > 0) {

         /* request a buffer */
         void *cookie = NULL;
         int next_rdt = (dev->rdt + 1) % dev->rx_size;

         uintptr_t phys = driver->i_cb.allocate_rx_buf ? driver->i_cb.allocate_rx_buf(driver->cb_cookie, BUF_SIZE, &cookie) : 0;
         if (!phys) {
             break;
         }

         dev->rx_cookies[dev->rdt] = cookie;

         dev->rx_ring[dev->rdt].status = 0;

         /* Remove the used bit so the controller knows this descriptor is
          * available to be written to */
         dev->rx_ring[dev->rdt].addr &= ~(ZYNQ_GEM_RXBUF_NEW_MASK | ZYNQ_GEM_RXBUF_ADD_MASK);

         dev->rx_ring[dev->rdt].addr |= (phys & ZYNQ_GEM_RXBUF_ADD_MASK);

         __sync_synchronize();

         dev->rdt = next_rdt;
         dev->rx_remain--;
     }

     __sync_synchronize();

     if (dev->rdt != dev->rdh && !zynq_gem_recv_enabled(dev->eth_dev)) {
         zynq_gem_recv_enable(dev->eth_dev);
     }
 }

 static void complete_rx(struct eth_driver *eth_driver)
 {

     struct zynq7000_eth_data *dev = (struct zynq7000_eth_data *)eth_driver->eth_data;
     unsigned int rdt = dev->rdt;

     while (dev->rdh != rdt) {
         unsigned int status = dev->rx_ring[dev->rdh].status;
         unsigned int addr = dev->rx_ring[dev->rdh].addr;

         /* Ensure no memory references get ordered before we checked the descriptor was written back */
         __sync_synchronize();
         if (!(addr & ZYNQ_GEM_RXBUF_NEW_MASK)) {
             /* not complete yet */
             break;
         }

         // TBD: Need to handle multiple buffers for single frame?
         void *cookie = dev->rx_cookies[dev->rdh];
         unsigned int len = status & ZYNQ_GEM_RXBUF_LEN_MASK;

         /* update rdh */
         dev->rdh = (dev->rdh + 1) % dev->rx_size;
         dev->rx_remain++;

         /* Give the buffers back */
         eth_driver->i_cb.rx_complete(eth_driver->cb_cookie, 1, &cookie, &len);
     }

     if (dev->rdt != dev->rdh && !zynq_gem_recv_enabled(dev->eth_dev)) {
         zynq_gem_recv_enabled(dev->eth_dev);
     }
 }

 static void complete_tx(struct eth_driver *driver)
 {

     struct zynq7000_eth_data *dev = (struct zynq7000_eth_data *)driver->eth_data;

     while (dev->tdh != dev->tdt) {
         unsigned int i;

         for (i = 0; i < dev->tx_lengths[dev->tdh]; i++) {
             int ring_pos = (i + dev->tdh) % dev->tx_size;

             if (i == 0 && !(dev->tx_ring[ring_pos].status & ZYNQ_GEM_TXBUF_USED_MASK)) {
                 /* not all parts complete */
                 return;
             }

             dev->tx_ring[ring_pos].status &= (ZYNQ_GEM_TXBUF_USED_MASK | ZYNQ_GEM_TXBUF_WRAP_MASK);
             dev->tx_ring[ring_pos].status |= ZYNQ_GEM_TXBUF_USED_MASK;
         }

         /* do not let memory loads happen before our checking of the descriptor write back */
         __sync_synchronize();

         /* increase TX Descriptor head */
         void *cookie = dev->tx_cookies[dev->tdh];
         dev->tx_remain += dev->tx_lengths[dev->tdh];
         dev->tdh = (dev->tdh + dev->tx_lengths[dev->tdh]) % dev->tx_size;

         /* give the buffer back */
         driver->i_cb.tx_complete(driver->cb_cookie, cookie);
     }

     if (dev->tdh != dev->tdt) {
         zynq_gem_start_send(dev->eth_dev);
     }
 }

 static void handle_irq(struct eth_driver *driver, int irq)
 {
     struct zynq7000_eth_data *eth_data = (struct zynq7000_eth_data *)driver->eth_data;
     struct zynq_gem_regs *regs = (struct zynq_gem_regs *)eth_data->eth_dev->iobase;

     // Clear Interrupts
     u32 isr = readl(&regs->isr);
     writel(isr, &regs->isr);

     if (isr & ZYNQ_GEM_IXR_TXCOMPLETE) {
         /* Clear TX Status register */
         u32 val = readl(&regs->txsr);
         writel(val, &regs->txsr);

         complete_tx(driver);
     }

     if (isr & ZYNQ_GEM_IXR_FRAMERX) {
         /* Clear RX Status register */
         u32 val = readl(&regs->rxsr);
         writel(val, &regs->rxsr);

         complete_rx(driver);
         fill_rx_bufs(driver);
     }
 }

 /* This is a platsuport IRQ interface IRQ handler wrapper for handle_irq() */
 static void eth_irq_handle(void *data, ps_irq_acknowledge_fn_t acknowledge_fn, void *ack_data)
 {
     ZF_LOGF_IF(data == NULL, "Passed in NULL for the data");
     struct eth_driver *driver = data;

     /* handle_irq doesn't really expect an IRQ number */
     handle_irq(driver, 0);

     int error = acknowledge_fn(ack_data);
     if (error) {
         LOG_ERROR("Failed to acknowledge the Ethernet device's IRQ");
     }
 }

 static void print_state(struct eth_driver *eth_driver)
 {
     printf("Zynq7000: print_state not implemented\n");
 }

 static void low_level_init(struct eth_driver *driver, uint8_t *mac, int *mtu)
 {
     printf("Zynq7000: low_level_init not implemented\n");
 }

 static int raw_tx(struct eth_driver *driver, unsigned int num, uintptr_t *phys, unsigned int *len, void *cookie)
 {

     struct zynq7000_eth_data *dev = (struct zynq7000_eth_data *)driver->eth_data;

     /* Ensure we have room */
     if (dev->tx_remain < num) {
         /* try and complete some */
         complete_tx(driver);

         if (dev->tx_remain < num) {
             return ETHIF_TX_FAILED;
         }
     }

     unsigned int i;
     __sync_synchronize();

     for (i = 0; i < num; i++) {
         unsigned int ring = (dev->tdt + i) % dev->tx_size;
         dev->tx_ring[ring].addr = phys[i];
         dev->tx_ring[ring].status &= ~(ZYNQ_GEM_TXBUF_USED_MASK | ZYNQ_GEM_TXBUF_FRMLEN_MASK | ZYNQ_GEM_TXBUF_LAST_MASK);
         dev->tx_ring[ring].status |= (len[i] & ZYNQ_GEM_TXBUF_FRMLEN_MASK);
         if (i == (num - 1)) {
             dev->tx_ring[ring].status |= ZYNQ_GEM_TXBUF_LAST_MASK;
         }
     }

     dev->tx_cookies[dev->tdt] = cookie;
     dev->tx_lengths[dev->tdt] = num;
     dev->tdt = (dev->tdt + num) % dev->tx_size;
     dev->tx_remain -= num;

     __sync_synchronize();

     zynq_gem_start_send(dev->eth_dev);

     return ETHIF_TX_ENQUEUED;
 }

 static void raw_poll(struct eth_driver *driver)
 {
     complete_rx(driver);
     complete_tx(driver);
     fill_rx_bufs(driver);
 }

 static void get_mac(struct eth_driver *driver, uint8_t *mac)
 {
     struct eth_device *eth_dev = ((struct zynq7000_eth_data *)driver->eth_data)->eth_dev;
     memcpy(mac, eth_dev->enetaddr, 6);
 }


 static struct raw_iface_funcs iface_fns = {
     .raw_handleIRQ = handle_irq,
     .print_state = print_state,
     .low_level_init = low_level_init,
     .raw_tx = raw_tx,
     .raw_poll = raw_poll,
     .get_mac = get_mac
 };

 int ethif_zynq7000_init(struct eth_driver *eth_driver, ps_io_ops_t io_ops, void *config)
 {
     int err;
     struct arm_eth_plat_config *plat_config = (struct arm_eth_plat_config *)config;
     struct zynq7000_eth_data *eth_data = NULL;
     struct eth_device *eth_dev;

     printf("ethif_zynq7000_init: Start\n");

     eth_data = (struct zynq7000_eth_data *)malloc(sizeof(struct zynq7000_eth_data));
     if (eth_data == NULL) {
         LOG_ERROR("Failed to allocate eth data struct");
         goto error;
     }

     if (config == NULL) {
         LOG_ERROR("Cannot get platform info; Passed in Config Pointer NULL");
         goto error;
     }
     uint32_t base_addr = (uint32_t)plat_config->buffer_addr;

     eth_data->tx_size = CONFIG_LIB_ETHDRIVER_TX_DESC_COUNT;
     eth_data->rx_size = CONFIG_LIB_ETHDRIVER_RX_DESC_COUNT;
     eth_driver->eth_data = eth_data;
     eth_driver->dma_alignment = ARCH_DMA_MINALIGN;
     eth_driver->i_fn = iface_fns;

     /* Initialize Descriptors */
     err = initialize_desc_ring(eth_data, &io_ops.dma_manager);
     if (err) {
         LOG_ERROR("Failed to allocate descriptor rings");
         goto error;
     }

 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII) || defined(CONFIG_PHYLIB)
     miiphy_init();
 #endif

 #ifdef CONFIG_PHYLIB
     phy_init();
 #endif

     zynq_set_gem_ioops(&io_ops);

     eth_dev = (struct eth_device *)zynq_gem_initialize(base_addr,
                                                        CONFIG_ZYNQ_GEM_PHY_ADDR0,
                                                        CONFIG_ZYNQ_GEM_EMIO0);
     if (NULL == eth_dev) {
         LOG_ERROR("Failed to initialize Zynq Ethernet Device");
         goto error;
     }
     eth_data->eth_dev = eth_dev;

     struct zynq_gem_regs *regs = (struct zynq_gem_regs *)eth_dev->iobase;

     /* Initialize the buffer descriptor registers */
     writel((uint32_t)eth_data->tx_ring_phys, &regs->txqbase);
     writel((uint32_t)eth_data->rx_ring_phys, &regs->rxqbase);

     zynq_gem_init(eth_dev);

     if (plat_config->prom_mode) {
         zynq_gem_prom_enable(eth_dev);
     } else {
         zynq_gem_prom_disable(eth_dev);
     }

     fill_rx_bufs(eth_driver);

     /* done */
     return 0;
 error:
     if (eth_data != NULL) {
         free(eth_data);
     }
     free_desc_ring(eth_data, &io_ops.dma_manager);
     return -1;
 }

 typedef struct {
     void *addr;
     ps_io_ops_t *io_ops;
     struct eth_driver *eth_driver;
     int irq_id;
 } callback_args_t;

 static int allocate_register_callback(pmem_region_t pmem, unsigned curr_num, size_t num_regs, void *token)
 {
     if (token == NULL) {
         ZF_LOGE("Expected a token!");
         return -EINVAL;
     }

     callback_args_t *args = token;
     if (curr_num == 0) {
         args->addr = ps_pmem_map(args->io_ops, pmem, false, PS_MEM_NORMAL);
         if (!args->addr) {
             ZF_LOGE("Failed to map the Ethernet device");
             return -EIO;
         }
     }

     return 0;
 }

 static int allocate_irq_callback(ps_irq_t irq, unsigned curr_num, size_t num_irqs, void *token)
 {
     if (token == NULL) {
         ZF_LOGE("Expected a token!");
         return -EINVAL;
     }

     callback_args_t *args = token;
     if (curr_num == 0) {
         args->irq_id = ps_irq_register(&args->io_ops->irq_ops, irq, eth_irq_handle, args->eth_driver);
         if (args->irq_id < 0) {
             ZF_LOGE("Failed to register the Ethernet device's IRQ");
             return -EIO;
         }
     }

     return 0;
 }

 int ethif_zynq7000_init_module(ps_io_ops_t *io_ops, const char *dev_path)
 {
     struct arm_eth_plat_config plat_config;
     struct eth_driver *eth_driver;

     int error = ps_calloc(&io_ops->malloc_ops, 1, sizeof(*eth_driver), (void **) &eth_driver);
     if (error) {
         ZF_LOGE("Failed to allocate memory for the Ethernet driver");
         return -ENOMEM;
     }

     ps_fdt_cookie_t *cookie = NULL;
     callback_args_t args = { .io_ops = io_ops, .eth_driver = eth_driver };
     error = ps_fdt_read_path(&io_ops->io_fdt, &io_ops->malloc_ops, (char *) dev_path, &cookie);
     if (error) {
         ZF_LOGE("Failed to read the path of the Ethernet device");
         return -ENODEV;
     }

     error = ps_fdt_walk_registers(&io_ops->io_fdt, cookie, allocate_register_callback, &args);
     if (error) {
         ZF_LOGE("Failed to walk the Ethernet device's registers and allocate them");
         return -ENODEV;
     }

     error = ps_fdt_walk_irqs(&io_ops->io_fdt, cookie, allocate_irq_callback, &args);
     if (error) {
         ZF_LOGE("Failed to walk the Ethernet device's IRQs and allocate them");
         return -ENODEV;
     }

     error = ps_fdt_cleanup_cookie(&io_ops->malloc_ops, cookie);
     if (error) {
         ZF_LOGE("Failed to free the cookie used to allocate resources");
         return -ENODEV;
     }

     /* Setup the config and hand initialisation off to the proper
      * initialisation method */
     plat_config.buffer_addr = args.addr;
     plat_config.prom_mode = 1;

     error = ethif_zynq7000_init(eth_driver, *io_ops, &plat_config);
     if (error) {
         ZF_LOGE("Failed to initialise the Ethernet driver");
         return -ENODEV;
     }

     return ps_interface_register(&io_ops->interface_registration_ops, PS_ETHERNET_INTERFACE, eth_driver, NULL);
 }

 static const char *compatible_strings[] = {
     "cdns,zynq-gem",
     "cdns,gem",
     NULL
 };
 PS_DRIVER_MODULE_DEFINE(zynq7000_gem, compatible_strings, ethif_zynq7000_init_module);
	/*
	* Copyright 2017, DornerWorks, Ltd.
	* Copyright 2017, Data61, CSIRO (ABN 41 687 119 230)
	*
	* SPDX-License-Identifier: GPL-2.0-only
	*/

	#include "unimplemented.h"
	#include "io.h"
	#include <platsupport/driver_module.h>
	#include <platsupport/fdt.h>
	#include <ethdrivers/gen_config.h>
	#include <ethdrivers/zynq7000.h>
	#include <ethdrivers/raw.h>
	#include <ethdrivers/helpers.h>
	#include <string.h>
	#include <utils/util.h>
	#include "zynq_gem.h"
	#include "uboot/net.h"
	#include "uboot/miiphy.h"
	#include "uboot/phy.h"
	#include <stdio.h>

	#define BUF_SIZE MAX_PKT_SIZE

	struct zynq7000_eth_data {
	struct eth_device *eth_dev;
	uintptr_t tx_ring_phys;
	uintptr_t rx_ring_phys;
	volatile struct emac_bd *tx_ring;
	volatile struct emac_bd *rx_ring;
	unsigned int rx_size;
	unsigned int tx_size;
	void **rx_cookies;
	unsigned int rx_remain;
	unsigned int tx_remain;
	void **tx_cookies;
	unsigned int *tx_lengths;
	/* track where the head and tail of the queues are for
	* enqueueing buffers / checking for completions */
	unsigned int rdt, rdh, tdt, tdh;
	};

	static void free_desc_ring(struct zynq7000_eth_data dev, ps_dma_man_t dma_man)
	{

	if (dev->rx_ring != NULL) {
	dma_unpin_free(dma_man, (void )dev->rx_ring, sizeof(struct emac_bd) dev->rx_size);
	dev->rx_ring = NULL;
	}

	if (dev->tx_ring != NULL) {
	dma_unpin_free(dma_man, (void )dev->tx_ring, sizeof(struct emac_bd) dev->tx_size);
	dev->tx_ring = NULL;
	}

	if (dev->rx_cookies != NULL) {
	free(dev->rx_cookies);
	dev->rx_cookies = NULL;
	}

	if (dev->tx_cookies != NULL) {
	free(dev->tx_cookies);
	dev->tx_cookies = NULL;
	}

	if (dev->tx_lengths != NULL) {
	free(dev->tx_lengths);
	dev->tx_lengths = NULL;
	}
	}

	static int initialize_desc_ring(struct zynq7000_eth_data dev, ps_dma_man_t dma_man)
	{
	dma_addr_t rx_ring = dma_alloc_pin(dma_man, sizeof(struct emac_bd) * dev->rx_size, 0, ARCH_DMA_MINALIGN);
	if (!rx_ring.phys) {
	LOG_ERROR("Failed to allocate rx_ring");
	return -1;
	}

	dev->rx_ring = rx_ring.virt;
	dev->rx_ring_phys = rx_ring.phys;
	dma_addr_t tx_ring = dma_alloc_pin(dma_man, sizeof(struct emac_bd) * dev->tx_size, 0, ARCH_DMA_MINALIGN);
	if (!tx_ring.phys) {
	LOG_ERROR("Failed to allocate tx_ring");
	free_desc_ring(dev, dma_man);
	return -1;
	}

	ps_dma_cache_clean_invalidate(dma_man, rx_ring.virt, sizeof(struct emac_bd) * dev->rx_size);
	ps_dma_cache_clean_invalidate(dma_man, tx_ring.virt, sizeof(struct emac_bd) * dev->tx_size);

	dev->rx_cookies = malloc(sizeof(void ) dev->rx_size);
	dev->tx_cookies = malloc(sizeof(void ) dev->tx_size);
	dev->tx_lengths = malloc(sizeof(unsigned int) * dev->tx_size);

	if (dev->rx_cookies == NULL \|\| dev->tx_cookies == NULL \|\| dev->tx_lengths == NULL) {

	if (dev->rx_cookies != NULL) {
	free(dev->rx_cookies);
	}

	if (dev->tx_cookies != NULL) {
	free(dev->tx_cookies);
	}

	if (dev->tx_lengths != NULL) {
	free(dev->tx_lengths);
	}

	LOG_ERROR("Failed to malloc");
	free_desc_ring(dev, dma_man);
	return -1;
	}

	dev->tx_ring = tx_ring.virt;
	dev->tx_ring_phys = tx_ring.phys;

	/* Remaining needs to be 2 less than size as we cannot actually enqueue size many descriptors,
	* since then the head and tail pointers would be equal, indicating empty. */
	dev->rx_remain = dev->rx_size - 2;
	dev->tx_remain = dev->tx_size - 2;

	dev->rdt = dev->rdh = dev->tdt = dev->tdh = 0;

	/* initialise both rings */
	for (unsigned int i = 0; i < dev->tx_size; i++) {
	dev->tx_ring[i] = (struct emac_bd) {
	.addr = 0,
	.status = ZYNQ_GEM_TXBUF_USED_MASK
	};
	}

	dev->tx_ring[dev->tx_size - 1].status \|= ZYNQ_GEM_TXBUF_WRAP_MASK;

	for (unsigned int i = 0; i < dev->rx_size; i++) {
	dev->rx_ring[i] = (struct emac_bd) {
	.addr = ZYNQ_GEM_RXBUF_NEW_MASK,
	.status = 0
	};
	}

	dev->rx_ring[dev->rx_size - 1].addr \|= ZYNQ_GEM_RXBUF_WRAP_MASK;

	__sync_synchronize();

	return 0;
	}

	static void fill_rx_bufs(struct eth_driver *driver)
	{

	struct zynq7000_eth_data dev = (struct zynq7000_eth_data )driver->eth_data;
	__sync_synchronize();

	while (dev->rx_remain > 0) {

	/* request a buffer */
	void *cookie = NULL;
	int next_rdt = (dev->rdt + 1) % dev->rx_size;

	uintptr_t phys = driver->i_cb.allocate_rx_buf ? driver->i_cb.allocate_rx_buf(driver->cb_cookie, BUF_SIZE, &cookie) : 0;
	if (!phys) {
	break;
	}

	dev->rx_cookies[dev->rdt] = cookie;

	dev->rx_ring[dev->rdt].status = 0;

	/* Remove the used bit so the controller knows this descriptor is
	* available to be written to */
	dev->rx_ring[dev->rdt].addr &= ~(ZYNQ_GEM_RXBUF_NEW_MASK \| ZYNQ_GEM_RXBUF_ADD_MASK);

	dev->rx_ring[dev->rdt].addr \|= (phys & ZYNQ_GEM_RXBUF_ADD_MASK);

	__sync_synchronize();

	dev->rdt = next_rdt;
	dev->rx_remain--;
	}

	__sync_synchronize();

	if (dev->rdt != dev->rdh && !zynq_gem_recv_enabled(dev->eth_dev)) {
	zynq_gem_recv_enable(dev->eth_dev);
	}
	}

	static void complete_rx(struct eth_driver *eth_driver)
	{

	struct zynq7000_eth_data dev = (struct zynq7000_eth_data )eth_driver->eth_data;
	unsigned int rdt = dev->rdt;

	while (dev->rdh != rdt) {
	unsigned int status = dev->rx_ring[dev->rdh].status;
	unsigned int addr = dev->rx_ring[dev->rdh].addr;

	/* Ensure no memory references get ordered before we checked the descriptor was written back */
	__sync_synchronize();
	if (!(addr & ZYNQ_GEM_RXBUF_NEW_MASK)) {
	/* not complete yet */
	break;
	}

	// TBD: Need to handle multiple buffers for single frame?
	void *cookie = dev->rx_cookies[dev->rdh];
	unsigned int len = status & ZYNQ_GEM_RXBUF_LEN_MASK;

	/* update rdh */
	dev->rdh = (dev->rdh + 1) % dev->rx_size;
	dev->rx_remain++;

	/* Give the buffers back */
	eth_driver->i_cb.rx_complete(eth_driver->cb_cookie, 1, &cookie, &len);
	}

	if (dev->rdt != dev->rdh && !zynq_gem_recv_enabled(dev->eth_dev)) {
	zynq_gem_recv_enabled(dev->eth_dev);
	}
	}

	static void complete_tx(struct eth_driver *driver)
	{

	struct zynq7000_eth_data dev = (struct zynq7000_eth_data )driver->eth_data;

	while (dev->tdh != dev->tdt) {
	unsigned int i;

	for (i = 0; i < dev->tx_lengths[dev->tdh]; i++) {
	int ring_pos = (i + dev->tdh) % dev->tx_size;

	if (i == 0 && !(dev->tx_ring[ring_pos].status & ZYNQ_GEM_TXBUF_USED_MASK)) {
	/* not all parts complete */
	return;
	}

	dev->tx_ring[ring_pos].status &= (ZYNQ_GEM_TXBUF_USED_MASK \| ZYNQ_GEM_TXBUF_WRAP_MASK);
	dev->tx_ring[ring_pos].status \|= ZYNQ_GEM_TXBUF_USED_MASK;
	}

	/* do not let memory loads happen before our checking of the descriptor write back */
	__sync_synchronize();

	/* increase TX Descriptor head */
	void *cookie = dev->tx_cookies[dev->tdh];
	dev->tx_remain += dev->tx_lengths[dev->tdh];
	dev->tdh = (dev->tdh + dev->tx_lengths[dev->tdh]) % dev->tx_size;

	/* give the buffer back */
	driver->i_cb.tx_complete(driver->cb_cookie, cookie);
	}

	if (dev->tdh != dev->tdt) {
	zynq_gem_start_send(dev->eth_dev);
	}
	}

	static void handle_irq(struct eth_driver *driver, int irq)
	{
	struct zynq7000_eth_data eth_data = (struct zynq7000_eth_data )driver->eth_data;
	struct zynq_gem_regs regs = (struct zynq_gem_regs )eth_data->eth_dev->iobase;

	// Clear Interrupts
	u32 isr = readl(&regs->isr);
	writel(isr, &regs->isr);

	if (isr & ZYNQ_GEM_IXR_TXCOMPLETE) {
	/* Clear TX Status register */
	u32 val = readl(&regs->txsr);
	writel(val, &regs->txsr);

	complete_tx(driver);
	}

	if (isr & ZYNQ_GEM_IXR_FRAMERX) {
	/* Clear RX Status register */
	u32 val = readl(&regs->rxsr);
	writel(val, &regs->rxsr);

	complete_rx(driver);
	fill_rx_bufs(driver);
	}
	}

	/* This is a platsuport IRQ interface IRQ handler wrapper for handle_irq() */
	static void eth_irq_handle(void data, ps_irq_acknowledge_fn_t acknowledge_fn, void ack_data)
	{
	ZF_LOGF_IF(data == NULL, "Passed in NULL for the data");
	struct eth_driver *driver = data;

	/* handle_irq doesn't really expect an IRQ number */
	handle_irq(driver, 0);

	int error = acknowledge_fn(ack_data);
	if (error) {
	LOG_ERROR("Failed to acknowledge the Ethernet device's IRQ");
	}
	}

	static void print_state(struct eth_driver *eth_driver)
	{
	printf("Zynq7000: print_state not implemented\n");
	}

	static void low_level_init(struct eth_driver driver, uint8_t mac, int *mtu)
	{
	printf("Zynq7000: low_level_init not implemented\n");
	}

	static int raw_tx(struct eth_driver driver, unsigned int num, uintptr_t phys, unsigned int len, void cookie)
	{

	struct zynq7000_eth_data dev = (struct zynq7000_eth_data )driver->eth_data;

	/* Ensure we have room */
	if (dev->tx_remain < num) {
	/* try and complete some */
	complete_tx(driver);

	if (dev->tx_remain < num) {
	return ETHIF_TX_FAILED;
	}
	}

	unsigned int i;
	__sync_synchronize();

	for (i = 0; i < num; i++) {
	unsigned int ring = (dev->tdt + i) % dev->tx_size;
	dev->tx_ring[ring].addr = phys[i];
	dev->tx_ring[ring].status &= ~(ZYNQ_GEM_TXBUF_USED_MASK \| ZYNQ_GEM_TXBUF_FRMLEN_MASK \| ZYNQ_GEM_TXBUF_LAST_MASK);
	dev->tx_ring[ring].status \|= (len[i] & ZYNQ_GEM_TXBUF_FRMLEN_MASK);
	if (i == (num - 1)) {
	dev->tx_ring[ring].status \|= ZYNQ_GEM_TXBUF_LAST_MASK;
	}
	}

	dev->tx_cookies[dev->tdt] = cookie;
	dev->tx_lengths[dev->tdt] = num;
	dev->tdt = (dev->tdt + num) % dev->tx_size;
	dev->tx_remain -= num;

	__sync_synchronize();

	zynq_gem_start_send(dev->eth_dev);

	return ETHIF_TX_ENQUEUED;
	}

	static void raw_poll(struct eth_driver *driver)
	{
	complete_rx(driver);
	complete_tx(driver);
	fill_rx_bufs(driver);
	}

	static void get_mac(struct eth_driver driver, uint8_t mac)
	{
	struct eth_device eth_dev = ((struct zynq7000_eth_data )driver->eth_data)->eth_dev;
	memcpy(mac, eth_dev->enetaddr, 6);
	}


	static struct raw_iface_funcs iface_fns = {
	.raw_handleIRQ = handle_irq,
	.print_state = print_state,
	.low_level_init = low_level_init,
	.raw_tx = raw_tx,
	.raw_poll = raw_poll,
	.get_mac = get_mac
	};

	int ethif_zynq7000_init(struct eth_driver eth_driver, ps_io_ops_t io_ops, void config)
	{
	int err;
	struct arm_eth_plat_config plat_config = (struct arm_eth_plat_config )config;
	struct zynq7000_eth_data *eth_data = NULL;
	struct eth_device *eth_dev;

	printf("ethif_zynq7000_init: Start\n");

	eth_data = (struct zynq7000_eth_data *)malloc(sizeof(struct zynq7000_eth_data));
	if (eth_data == NULL) {
	LOG_ERROR("Failed to allocate eth data struct");
	goto error;
	}

	if (config == NULL) {
	LOG_ERROR("Cannot get platform info; Passed in Config Pointer NULL");
	goto error;
	}
	uint32_t base_addr = (uint32_t)plat_config->buffer_addr;

	eth_data->tx_size = CONFIG_LIB_ETHDRIVER_TX_DESC_COUNT;
	eth_data->rx_size = CONFIG_LIB_ETHDRIVER_RX_DESC_COUNT;
	eth_driver->eth_data = eth_data;
	eth_driver->dma_alignment = ARCH_DMA_MINALIGN;
	eth_driver->i_fn = iface_fns;

	/* Initialize Descriptors */
	err = initialize_desc_ring(eth_data, &io_ops.dma_manager);
	if (err) {
	LOG_ERROR("Failed to allocate descriptor rings");
	goto error;
	}

	#if defined(CONFIG_MII) \|\| defined(CONFIG_CMD_MII) \|\| defined(CONFIG_PHYLIB)
	miiphy_init();
	#endif

	#ifdef CONFIG_PHYLIB
	phy_init();
	#endif

	zynq_set_gem_ioops(&io_ops);

	eth_dev = (struct eth_device *)zynq_gem_initialize(base_addr,
	CONFIG_ZYNQ_GEM_PHY_ADDR0,
	CONFIG_ZYNQ_GEM_EMIO0);
	if (NULL == eth_dev) {
	LOG_ERROR("Failed to initialize Zynq Ethernet Device");
	goto error;
	}
	eth_data->eth_dev = eth_dev;

	struct zynq_gem_regs regs = (struct zynq_gem_regs )eth_dev->iobase;

	/* Initialize the buffer descriptor registers */
	writel((uint32_t)eth_data->tx_ring_phys, &regs->txqbase);
	writel((uint32_t)eth_data->rx_ring_phys, &regs->rxqbase);

	zynq_gem_init(eth_dev);

	if (plat_config->prom_mode) {
	zynq_gem_prom_enable(eth_dev);
	} else {
	zynq_gem_prom_disable(eth_dev);
	}

	fill_rx_bufs(eth_driver);

	/* done */
	return 0;
	error:
	if (eth_data != NULL) {
	free(eth_data);
	}
	free_desc_ring(eth_data, &io_ops.dma_manager);
	return -1;
	}

	typedef struct {
	void *addr;
	ps_io_ops_t *io_ops;
	struct eth_driver *eth_driver;
	int irq_id;
	} callback_args_t;

	static int allocate_register_callback(pmem_region_t pmem, unsigned curr_num, size_t num_regs, void *token)
	{
	if (token == NULL) {
	ZF_LOGE("Expected a token!");
	return -EINVAL;
	}

	callback_args_t *args = token;
	if (curr_num == 0) {
	args->addr = ps_pmem_map(args->io_ops, pmem, false, PS_MEM_NORMAL);
	if (!args->addr) {
	ZF_LOGE("Failed to map the Ethernet device");
	return -EIO;
	}
	}

	return 0;
	}

	static int allocate_irq_callback(ps_irq_t irq, unsigned curr_num, size_t num_irqs, void *token)
	{
	if (token == NULL) {
	ZF_LOGE("Expected a token!");
	return -EINVAL;
	}

	callback_args_t *args = token;
	if (curr_num == 0) {
	args->irq_id = ps_irq_register(&args->io_ops->irq_ops, irq, eth_irq_handle, args->eth_driver);
	if (args->irq_id < 0) {
	ZF_LOGE("Failed to register the Ethernet device's IRQ");
	return -EIO;
	}
	}

	return 0;
	}

	int ethif_zynq7000_init_module(ps_io_ops_t io_ops, const char dev_path)
	{
	struct arm_eth_plat_config plat_config;
	struct eth_driver *eth_driver;

	int error = ps_calloc(&io_ops->malloc_ops, 1, sizeof(eth_driver), (void *) &eth_driver);
	if (error) {
	ZF_LOGE("Failed to allocate memory for the Ethernet driver");
	return -ENOMEM;
	}

	ps_fdt_cookie_t *cookie = NULL;
	callback_args_t args = { .io_ops = io_ops, .eth_driver = eth_driver };
	error = ps_fdt_read_path(&io_ops->io_fdt, &io_ops->malloc_ops, (char *) dev_path, &cookie);
	if (error) {
	ZF_LOGE("Failed to read the path of the Ethernet device");
	return -ENODEV;
	}

	error = ps_fdt_walk_registers(&io_ops->io_fdt, cookie, allocate_register_callback, &args);
	if (error) {
	ZF_LOGE("Failed to walk the Ethernet device's registers and allocate them");
	return -ENODEV;
	}

	error = ps_fdt_walk_irqs(&io_ops->io_fdt, cookie, allocate_irq_callback, &args);
	if (error) {
	ZF_LOGE("Failed to walk the Ethernet device's IRQs and allocate them");
	return -ENODEV;
	}

	error = ps_fdt_cleanup_cookie(&io_ops->malloc_ops, cookie);
	if (error) {
	ZF_LOGE("Failed to free the cookie used to allocate resources");
	return -ENODEV;
	}

	/* Setup the config and hand initialisation off to the proper
	* initialisation method */
	plat_config.buffer_addr = args.addr;
	plat_config.prom_mode = 1;

	error = ethif_zynq7000_init(eth_driver, *io_ops, &plat_config);
	if (error) {
	ZF_LOGE("Failed to initialise the Ethernet driver");
	return -ENODEV;
	}

	return ps_interface_register(&io_ops->interface_registration_ops, PS_ETHERNET_INTERFACE, eth_driver, NULL);
	}

	static const char *compatible_strings[] = {
	"cdns,zynq-gem",
	"cdns,gem",
	NULL
	};
	PS_DRIVER_MODULE_DEFINE(zynq7000_gem, compatible_strings, ethif_zynq7000_init_module);