text: /*
   * IBM Power Virtual Ethernet Device Driver
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, see <http://www.gnu.org/licenses/>.
   *
   * Copyright (C) IBM Corporation, 2003, 2010
   *
   * Authors: Dave Larson <larson1@us.ibm.com>
   *	    Santiago Leon <santil@linux.vnet.ibm.com>
   *	    Brian King <brking@linux.vnet.ibm.com>
   *	    Robert Jennings <rcj@linux.vnet.ibm.com>
   *	    Anton Blanchard <anton@au.ibm.com>
   */
  
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/dma-mapping.h>
  #include <linux/kernel.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/skbuff.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/mm.h>
  #include <linux/pm.h>
  #include <linux/ethtool.h>
  #include <linux/in.h>
  #include <linux/ip.h>
  #include <linux/ipv6.h>
  #include <linux/slab.h>
  #include <asm/hvcall.h>
  #include <linux/atomic.h>
  #include <asm/vio.h>
  #include <asm/iommu.h>
  #include <asm/firmware.h>
  #include <net/tcp.h>
  #include <net/ip6_checksum.h>
  
  #include "ibmveth.h"
  
  static irqreturn_t ibmveth_interrupt(int irq, void *dev_instance);
  static void ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter);
  static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev);
  
  static struct kobj_type ktype_veth_pool;
  
  
  static const char ibmveth_driver_name[] = "ibmveth";
  static const char ibmveth_driver_string[] = "IBM Power Virtual Ethernet Driver";
  #define ibmveth_driver_version "1.06"
  
  MODULE_AUTHOR("Santiago Leon <santil@linux.vnet.ibm.com>");
  MODULE_DESCRIPTION("IBM Power Virtual Ethernet Driver");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(ibmveth_driver_version);
  
  static unsigned int tx_copybreak __read_mostly = 128;
  module_param(tx_copybreak, uint, 0644);
  MODULE_PARM_DESC(tx_copybreak,
  	"Maximum size of packet that is copied to a new buffer on transmit");
  
  static unsigned int rx_copybreak __read_mostly = 128;
  module_param(rx_copybreak, uint, 0644);
  MODULE_PARM_DESC(rx_copybreak,
  	"Maximum size of packet that is copied to a new buffer on receive");
  
  static unsigned int rx_flush __read_mostly = 0;
  module_param(rx_flush, uint, 0644);
  MODULE_PARM_DESC(rx_flush, "Flush receive buffers before use");
  
  static bool old_large_send __read_mostly;
  module_param(old_large_send, bool, S_IRUGO);
  MODULE_PARM_DESC(old_large_send,
  	"Use old large send method on firmware that supports the new method");
  
  struct ibmveth_stat {
  	char name[ETH_GSTRING_LEN];
  	int offset;
  };
  
  #define IBMVETH_STAT_OFF(stat) offsetof(struct ibmveth_adapter, stat)
  #define IBMVETH_GET_STAT(a, off) *((u64 *)(((unsigned long)(a)) + off))
  
  struct ibmveth_stat ibmveth_stats[] = {
  	{ "replenish_task_cycles", IBMVETH_STAT_OFF(replenish_task_cycles) },
  	{ "replenish_no_mem", IBMVETH_STAT_OFF(replenish_no_mem) },
  	{ "replenish_add_buff_failure",
  			IBMVETH_STAT_OFF(replenish_add_buff_failure) },
  	{ "replenish_add_buff_success",
  			IBMVETH_STAT_OFF(replenish_add_buff_success) },
  	{ "rx_invalid_buffer", IBMVETH_STAT_OFF(rx_invalid_buffer) },
  	{ "rx_no_buffer", IBMVETH_STAT_OFF(rx_no_buffer) },
  	{ "tx_map_failed", IBMVETH_STAT_OFF(tx_map_failed) },
  	{ "tx_send_failed", IBMVETH_STAT_OFF(tx_send_failed) },
  	{ "fw_enabled_ipv4_csum", IBMVETH_STAT_OFF(fw_ipv4_csum_support) },
  	{ "fw_enabled_ipv6_csum", IBMVETH_STAT_OFF(fw_ipv6_csum_support) },
  	{ "tx_large_packets", IBMVETH_STAT_OFF(tx_large_packets) },
  	{ "rx_large_packets", IBMVETH_STAT_OFF(rx_large_packets) },
  	{ "fw_enabled_large_send", IBMVETH_STAT_OFF(fw_large_send_support) }
  };
  
  /* simple methods of getting data from the current rxq entry */
  static inline u32 ibmveth_rxq_flags(struct ibmveth_adapter *adapter)
  {
  	return be32_to_cpu(adapter->rx_queue.queue_addr[adapter->rx_queue.index].flags_off);
  }
  
  static inline int ibmveth_rxq_toggle(struct ibmveth_adapter *adapter)
  {
  	return (ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_TOGGLE) >>
  			IBMVETH_RXQ_TOGGLE_SHIFT;
  }
  
  static inline int ibmveth_rxq_pending_buffer(struct ibmveth_adapter *adapter)
  {
  	return ibmveth_rxq_toggle(adapter) == adapter->rx_queue.toggle;
  }
  
  static inline int ibmveth_rxq_buffer_valid(struct ibmveth_adapter *adapter)
  {
  	return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_VALID;
  }
  
  static inline int ibmveth_rxq_frame_offset(struct ibmveth_adapter *adapter)
  {
  	return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_OFF_MASK;
  }
  
  static inline int ibmveth_rxq_large_packet(struct ibmveth_adapter *adapter)
  {
  	return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_LRG_PKT;
  }
  
  static inline int ibmveth_rxq_frame_length(struct ibmveth_adapter *adapter)
  {
  	return be32_to_cpu(adapter->rx_queue.queue_addr[adapter->rx_queue.index].length);
  }
  
  static inline int ibmveth_rxq_csum_good(struct ibmveth_adapter *adapter)
  {
  	return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_CSUM_GOOD;
  }
  
  /* setup the initial settings for a buffer pool */
  static void ibmveth_init_buffer_pool(struct ibmveth_buff_pool *pool,
  				     u32 pool_index, u32 pool_size,
  				     u32 buff_size, u32 pool_active)
  {
  	pool->size = pool_size;
  	pool->index = pool_index;
  	pool->buff_size = buff_size;
  	pool->threshold = pool_size * 7 / 8;
  	pool->active = pool_active;
  }
  
  /* allocate and setup an buffer pool - called during open */
  static int ibmveth_alloc_buffer_pool(struct ibmveth_buff_pool *pool)
  {
  	int i;
  
  	pool->free_map = kmalloc(sizeof(u16) * pool->size, GFP_KERNEL);
  
  	if (!pool->free_map)
  		return -1;
  
  	pool->dma_addr = kcalloc(pool->size, sizeof(dma_addr_t), GFP_KERNEL);
  	if (!pool->dma_addr) {
  		kfree(pool->free_map);
  		pool->free_map = NULL;
  		return -1;
  	}
  
  	pool->skbuff = kcalloc(pool->size, sizeof(void *), GFP_KERNEL);
  
  	if (!pool->skbuff) {
  		kfree(pool->dma_addr);
  		pool->dma_addr = NULL;
  
  		kfree(pool->free_map);
  		pool->free_map = NULL;
  		return -1;
  	}
  
  	for (i = 0; i < pool->size; ++i)
  		pool->free_map[i] = i;
  
  	atomic_set(&pool->available, 0);
  	pool->producer_index = 0;
  	pool->consumer_index = 0;
  
  	return 0;
  }
  
  static inline void ibmveth_flush_buffer(void *addr, unsigned long length)
  {
  	unsigned long offset;
  
  	for (offset = 0; offset < length; offset += SMP_CACHE_BYTES)
  		asm("dcbfl %0,%1" :: "b" (addr), "r" (offset));
  }
  
  /* replenish the buffers for a pool.  note that we don't need to
   * skb_reserve these since they are used for incoming...
   */
  static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter,
  					  struct ibmveth_buff_pool *pool)
  {
  	u32 i;
  	u32 count = pool->size - atomic_read(&pool->available);
  	u32 buffers_added = 0;
  	struct sk_buff *skb;
  	unsigned int free_index, index;
  	u64 correlator;
  	unsigned long lpar_rc;
  	dma_addr_t dma_addr;
  
  	mb();
  
  	for (i = 0; i < count; ++i) {
  		union ibmveth_buf_desc desc;
  
  		skb = netdev_alloc_skb(adapter->netdev, pool->buff_size);
  
  		if (!skb) {
  			netdev_dbg(adapter->netdev,
  				   "replenish: unable to allocate skb\n");
  			adapter->replenish_no_mem++;
  			break;
  		}
  
  		free_index = pool->consumer_index;
  		pool->consumer_index++;
  		if (pool->consumer_index >= pool->size)
  			pool->consumer_index = 0;
  		index = pool->free_map[free_index];
  
  		BUG_ON(index == IBM_VETH_INVALID_MAP);
  		BUG_ON(pool->skbuff[index] != NULL);
  
  		dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
  				pool->buff_size, DMA_FROM_DEVICE);
  
  		if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
  			goto failure;
  
  		pool->free_map[free_index] = IBM_VETH_INVALID_MAP;
  		pool->dma_addr[index] = dma_addr;
  		pool->skbuff[index] = skb;
  
  		correlator = ((u64)pool->index << 32) | index;
  		*(u64 *)skb->data = correlator;
  
  		desc.fields.flags_len = IBMVETH_BUF_VALID | pool->buff_size;
  		desc.fields.address = dma_addr;
  
  		if (rx_flush) {
  			unsigned int len = min(pool->buff_size,
  						adapter->netdev->mtu +
  						IBMVETH_BUFF_OH);
  			ibmveth_flush_buffer(skb->data, len);
  		}
  		lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address,
  						   desc.desc);
  
  		if (lpar_rc != H_SUCCESS) {
  			goto failure;
  		} else {
  			buffers_added++;
  			adapter->replenish_add_buff_success++;
  		}
  	}
  
  	mb();
  	atomic_add(buffers_added, &(pool->available));
  	return;
  
  failure:
  	pool->free_map[free_index] = index;
  	pool->skbuff[index] = NULL;
  	if (pool->consumer_index == 0)
  		pool->consumer_index = pool->size - 1;
  	else
  		pool->consumer_index--;
  	if (!dma_mapping_error(&adapter->vdev->dev, dma_addr))
  		dma_unmap_single(&adapter->vdev->dev,
  		                 pool->dma_addr[index], pool->buff_size,
  		                 DMA_FROM_DEVICE);
  	dev_kfree_skb_any(skb);
  	adapter->replenish_add_buff_failure++;
  
  	mb();
  	atomic_add(buffers_added, &(pool->available));
  }
  
  /*
   * The final 8 bytes of the buffer list is a counter of frames dropped
   * because there was not a buffer in the buffer list capable of holding
   * the frame.
   */
  static void ibmveth_update_rx_no_buffer(struct ibmveth_adapter *adapter)
  {
  	__be64 *p = adapter->buffer_list_addr + 4096 - 8;
  
  	adapter->rx_no_buffer = be64_to_cpup(p);
  }
  
  /* replenish routine */
  static void ibmveth_replenish_task(struct ibmveth_adapter *adapter)
  {
  	int i;
  
  	adapter->replenish_task_cycles++;
  
  	for (i = (IBMVETH_NUM_BUFF_POOLS - 1); i >= 0; i--) {
  		struct ibmveth_buff_pool *pool = &adapter->rx_buff_pool[i];
  
  		if (pool->active &&
  		    (atomic_read(&pool->available) < pool->threshold))
  			ibmveth_replenish_buffer_pool(adapter, pool);
  	}
  
  	ibmveth_update_rx_no_buffer(adapter);
  }
  
  /* empty and free ana buffer pool - also used to do cleanup in error paths */
  static void ibmveth_free_buffer_pool(struct ibmveth_adapter *adapter,
  				     struct ibmveth_buff_pool *pool)
  {
  	int i;
  
  	kfree(pool->free_map);
  	pool->free_map = NULL;
  
  	if (pool->skbuff && pool->dma_addr) {
  		for (i = 0; i < pool->size; ++i) {
  			struct sk_buff *skb = pool->skbuff[i];
  			if (skb) {
  				dma_unmap_single(&adapter->vdev->dev,
  						 pool->dma_addr[i],
  						 pool->buff_size,
  						 DMA_FROM_DEVICE);
  				dev_kfree_skb_any(skb);
  				pool->skbuff[i] = NULL;
  			}
  		}
  	}
  
  	if (pool->dma_addr) {
  		kfree(pool->dma_addr);
  		pool->dma_addr = NULL;
  	}
  
  	if (pool->skbuff) {
  		kfree(pool->skbuff);
  		pool->skbuff = NULL;
  	}
  }
  
  /* remove a buffer from a pool */
  static void ibmveth_remove_buffer_from_pool(struct ibmveth_adapter *adapter,
  					    u64 correlator)
  {
  	unsigned int pool  = correlator >> 32;
  	unsigned int index = correlator & 0xffffffffUL;
  	unsigned int free_index;
  	struct sk_buff *skb;
  
  	BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
  	BUG_ON(index >= adapter->rx_buff_pool[pool].size);
  
  	skb = adapter->rx_buff_pool[pool].skbuff[index];
  
  	BUG_ON(skb == NULL);
  
  	adapter->rx_buff_pool[pool].skbuff[index] = NULL;
  
  	dma_unmap_single(&adapter->vdev->dev,
  			 adapter->rx_buff_pool[pool].dma_addr[index],
  			 adapter->rx_buff_pool[pool].buff_size,
  			 DMA_FROM_DEVICE);
  
  	free_index = adapter->rx_buff_pool[pool].producer_index;
  	adapter->rx_buff_pool[pool].producer_index++;
  	if (adapter->rx_buff_pool[pool].producer_index >=
  	    adapter->rx_buff_pool[pool].size)
  		adapter->rx_buff_pool[pool].producer_index = 0;
  	adapter->rx_buff_pool[pool].free_map[free_index] = index;
  
  	mb();
  
  	atomic_dec(&(adapter->rx_buff_pool[pool].available));
  }
  
  /* get the current buffer on the rx queue */
  static inline struct sk_buff *ibmveth_rxq_get_buffer(struct ibmveth_adapter *adapter)
  {
  	u64 correlator = adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator;
  	unsigned int pool = correlator >> 32;
  	unsigned int index = correlator & 0xffffffffUL;
  
  	BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
  	BUG_ON(index >= adapter->rx_buff_pool[pool].size);
  
  	return adapter->rx_buff_pool[pool].skbuff[index];
  }
  
  /* recycle the current buffer on the rx queue */
  static int ibmveth_rxq_recycle_buffer(struct ibmveth_adapter *adapter)
  {
  	u32 q_index = adapter->rx_queue.index;
  	u64 correlator = adapter->rx_queue.queue_addr[q_index].correlator;
  	unsigned int pool = correlator >> 32;
  	unsigned int index = correlator & 0xffffffffUL;
  	union ibmveth_buf_desc desc;
  	unsigned long lpar_rc;
  	int ret = 1;
  
  	BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
  	BUG_ON(index >= adapter->rx_buff_pool[pool].size);
  
  	if (!adapter->rx_buff_pool[pool].active) {
  		ibmveth_rxq_harvest_buffer(adapter);
  		ibmveth_free_buffer_pool(adapter, &adapter->rx_buff_pool[pool]);
  		goto out;
  	}
  
  	desc.fields.flags_len = IBMVETH_BUF_VALID |
  		adapter->rx_buff_pool[pool].buff_size;
  	desc.fields.address = adapter->rx_buff_pool[pool].dma_addr[index];
  
  	lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address, desc.desc);
  
  	if (lpar_rc != H_SUCCESS) {
  		netdev_dbg(adapter->netdev, "h_add_logical_lan_buffer failed "
  			   "during recycle rc=%ld", lpar_rc);
  		ibmveth_remove_buffer_from_pool(adapter, adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator);
  		ret = 0;
  	}
  
  	if (++adapter->rx_queue.index == adapter->rx_queue.num_slots) {
  		adapter->rx_queue.index = 0;
  		adapter->rx_queue.toggle = !adapter->rx_queue.toggle;
  	}
  
  out:
  	return ret;
  }
  
  static void ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter)
  {
  	ibmveth_remove_buffer_from_pool(adapter, adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator);
  
  	if (++adapter->rx_queue.index == adapter->rx_queue.num_slots) {
  		adapter->rx_queue.index = 0;
  		adapter->rx_queue.toggle = !adapter->rx_queue.toggle;
  	}
  }
  
  static int ibmveth_register_logical_lan(struct ibmveth_adapter *adapter,
          union ibmveth_buf_desc rxq_desc, u64 mac_address)
  {
  	int rc, try_again = 1;
  
  	/*
  	 * After a kexec the adapter will still be open, so our attempt to
  	 * open it will fail. So if we get a failure we free the adapter and
  	 * try again, but only once.
  	 */
  retry:
  	rc = h_register_logical_lan(adapter->vdev->unit_address,
  				    adapter->buffer_list_dma, rxq_desc.desc,
  				    adapter->filter_list_dma, mac_address);
  
  	if (rc != H_SUCCESS && try_again) {
  		do {
  			rc = h_free_logical_lan(adapter->vdev->unit_address);
  		} while (H_IS_LONG_BUSY(rc) || (rc == H_BUSY));
  
  		try_again = 0;
  		goto retry;
  	}
  
  	return rc;
  }
  
  static u64 ibmveth_encode_mac_addr(u8 *mac)
  {
  	int i;
  	u64 encoded = 0;
  
  	for (i = 0; i < ETH_ALEN; i++)
  		encoded = (encoded << 8) | mac[i];
  
  	return encoded;
  }
  
  static int ibmveth_open(struct net_device *netdev)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	u64 mac_address;
  	int rxq_entries = 1;
  	unsigned long lpar_rc;
  	int rc;
  	union ibmveth_buf_desc rxq_desc;
  	int i;
  	struct device *dev;
  
  	netdev_dbg(netdev, "open starting\n");
  
  	napi_enable(&adapter->napi);
  
  	for(i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
  		rxq_entries += adapter->rx_buff_pool[i].size;
  
  	rc = -ENOMEM;
  	adapter->buffer_list_addr = (void*) get_zeroed_page(GFP_KERNEL);
  	if (!adapter->buffer_list_addr) {
  		netdev_err(netdev, "unable to allocate list pages\n");
  		goto out;
  	}
  
  	adapter->filter_list_addr = (void*) get_zeroed_page(GFP_KERNEL);
  	if (!adapter->filter_list_addr) {
  		netdev_err(netdev, "unable to allocate filter pages\n");
  		goto out_free_buffer_list;
  	}
  
  	dev = &adapter->vdev->dev;
  
  	adapter->rx_queue.queue_len = sizeof(struct ibmveth_rx_q_entry) *
  						rxq_entries;
  	adapter->rx_queue.queue_addr =
  		dma_alloc_coherent(dev, adapter->rx_queue.queue_len,
  				   &adapter->rx_queue.queue_dma, GFP_KERNEL);
  	if (!adapter->rx_queue.queue_addr)
  		goto out_free_filter_list;
  
  	adapter->buffer_list_dma = dma_map_single(dev,
  			adapter->buffer_list_addr, 4096, DMA_BIDIRECTIONAL);
  	if (dma_mapping_error(dev, adapter->buffer_list_dma)) {
  		netdev_err(netdev, "unable to map buffer list pages\n");
  		goto out_free_queue_mem;
  	}
  
  	adapter->filter_list_dma = dma_map_single(dev,
  			adapter->filter_list_addr, 4096, DMA_BIDIRECTIONAL);
  	if (dma_mapping_error(dev, adapter->filter_list_dma)) {
  		netdev_err(netdev, "unable to map filter list pages\n");
  		goto out_unmap_buffer_list;
  	}
  
  	adapter->rx_queue.index = 0;
  	adapter->rx_queue.num_slots = rxq_entries;
  	adapter->rx_queue.toggle = 1;
  
  	mac_address = ibmveth_encode_mac_addr(netdev->dev_addr);
  
  	rxq_desc.fields.flags_len = IBMVETH_BUF_VALID |
  					adapter->rx_queue.queue_len;
  	rxq_desc.fields.address = adapter->rx_queue.queue_dma;
  
  	netdev_dbg(netdev, "buffer list @ 0x%p\n", adapter->buffer_list_addr);
  	netdev_dbg(netdev, "filter list @ 0x%p\n", adapter->filter_list_addr);
  	netdev_dbg(netdev, "receive q   @ 0x%p\n", adapter->rx_queue.queue_addr);
  
  	h_vio_signal(adapter->vdev->unit_address, VIO_IRQ_DISABLE);
  
  	lpar_rc = ibmveth_register_logical_lan(adapter, rxq_desc, mac_address);
  
  	if (lpar_rc != H_SUCCESS) {
  		netdev_err(netdev, "h_register_logical_lan failed with %ld\n",
  			   lpar_rc);
  		netdev_err(netdev, "buffer TCE:0x%llx filter TCE:0x%llx rxq "
  			   "desc:0x%llx MAC:0x%llx\n",
  				     adapter->buffer_list_dma,
  				     adapter->filter_list_dma,
  				     rxq_desc.desc,
  				     mac_address);
  		rc = -ENONET;
  		goto out_unmap_filter_list;
  	}
  
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
  		if (!adapter->rx_buff_pool[i].active)
  			continue;
  		if (ibmveth_alloc_buffer_pool(&adapter->rx_buff_pool[i])) {
  			netdev_err(netdev, "unable to alloc pool\n");
  			adapter->rx_buff_pool[i].active = 0;
  			rc = -ENOMEM;
  			goto out_free_buffer_pools;
  		}
  	}
  
  	netdev_dbg(netdev, "registering irq 0x%x\n", netdev->irq);
  	rc = request_irq(netdev->irq, ibmveth_interrupt, 0, netdev->name,
  			 netdev);
  	if (rc != 0) {
  		netdev_err(netdev, "unable to request irq 0x%x, rc %d\n",
  			   netdev->irq, rc);
  		do {
  			lpar_rc = h_free_logical_lan(adapter->vdev->unit_address);
  		} while (H_IS_LONG_BUSY(lpar_rc) || (lpar_rc == H_BUSY));
  
  		goto out_free_buffer_pools;
  	}
  
  	rc = -ENOMEM;
  	adapter->bounce_buffer =
  	    kmalloc(netdev->mtu + IBMVETH_BUFF_OH, GFP_KERNEL);
  	if (!adapter->bounce_buffer)
  		goto out_free_irq;
  
  	adapter->bounce_buffer_dma =
  	    dma_map_single(&adapter->vdev->dev, adapter->bounce_buffer,
  			   netdev->mtu + IBMVETH_BUFF_OH, DMA_BIDIRECTIONAL);
  	if (dma_mapping_error(dev, adapter->bounce_buffer_dma)) {
  		netdev_err(netdev, "unable to map bounce buffer\n");
  		goto out_free_bounce_buffer;
  	}
  
  	netdev_dbg(netdev, "initial replenish cycle\n");
  	ibmveth_interrupt(netdev->irq, netdev);
  
  	netif_start_queue(netdev);
  
  	netdev_dbg(netdev, "open complete\n");
  
  	return 0;
  
  out_free_bounce_buffer:
  	kfree(adapter->bounce_buffer);
  out_free_irq:
  	free_irq(netdev->irq, netdev);
  out_free_buffer_pools:
  	while (--i >= 0) {
  		if (adapter->rx_buff_pool[i].active)
  			ibmveth_free_buffer_pool(adapter,
  						 &adapter->rx_buff_pool[i]);
  	}
  out_unmap_filter_list:
  	dma_unmap_single(dev, adapter->filter_list_dma, 4096,
  			 DMA_BIDIRECTIONAL);
  out_unmap_buffer_list:
  	dma_unmap_single(dev, adapter->buffer_list_dma, 4096,
  			 DMA_BIDIRECTIONAL);
  out_free_queue_mem:
  	dma_free_coherent(dev, adapter->rx_queue.queue_len,
  			  adapter->rx_queue.queue_addr,
  			  adapter->rx_queue.queue_dma);
  out_free_filter_list:
  	free_page((unsigned long)adapter->filter_list_addr);
  out_free_buffer_list:
  	free_page((unsigned long)adapter->buffer_list_addr);
  out:
  	napi_disable(&adapter->napi);
  	return rc;
  }
  
  static int ibmveth_close(struct net_device *netdev)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	struct device *dev = &adapter->vdev->dev;
  	long lpar_rc;
  	int i;
  
  	netdev_dbg(netdev, "close starting\n");
  
  	napi_disable(&adapter->napi);
  
  	if (!adapter->pool_config)
  		netif_stop_queue(netdev);
  
  	h_vio_signal(adapter->vdev->unit_address, VIO_IRQ_DISABLE);
  
  	do {
  		lpar_rc = h_free_logical_lan(adapter->vdev->unit_address);
  	} while (H_IS_LONG_BUSY(lpar_rc) || (lpar_rc == H_BUSY));
  
  	if (lpar_rc != H_SUCCESS) {
  		netdev_err(netdev, "h_free_logical_lan failed with %lx, "
  			   "continuing with close\n", lpar_rc);
  	}
  
  	free_irq(netdev->irq, netdev);
  
  	ibmveth_update_rx_no_buffer(adapter);
  
  	dma_unmap_single(dev, adapter->buffer_list_dma, 4096,
  			 DMA_BIDIRECTIONAL);
  	free_page((unsigned long)adapter->buffer_list_addr);
  
  	dma_unmap_single(dev, adapter->filter_list_dma, 4096,
  			 DMA_BIDIRECTIONAL);
  	free_page((unsigned long)adapter->filter_list_addr);
  
  	dma_free_coherent(dev, adapter->rx_queue.queue_len,
  			  adapter->rx_queue.queue_addr,
  			  adapter->rx_queue.queue_dma);
  
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
  		if (adapter->rx_buff_pool[i].active)
  			ibmveth_free_buffer_pool(adapter,
  						 &adapter->rx_buff_pool[i]);
  
  	dma_unmap_single(&adapter->vdev->dev, adapter->bounce_buffer_dma,
  			 adapter->netdev->mtu + IBMVETH_BUFF_OH,
  			 DMA_BIDIRECTIONAL);
  	kfree(adapter->bounce_buffer);
  
  	netdev_dbg(netdev, "close complete\n");
  
  	return 0;
  }
  
  static int netdev_get_link_ksettings(struct net_device *dev,
  				     struct ethtool_link_ksettings *cmd)
  {
  	u32 supported, advertising;
  
  	supported = (SUPPORTED_1000baseT_Full | SUPPORTED_Autoneg |
  				SUPPORTED_FIBRE);
  	advertising = (ADVERTISED_1000baseT_Full | ADVERTISED_Autoneg |
  				ADVERTISED_FIBRE);
  	cmd->base.speed = SPEED_1000;
  	cmd->base.duplex = DUPLEX_FULL;
  	cmd->base.port = PORT_FIBRE;
  	cmd->base.phy_address = 0;
  	cmd->base.autoneg = AUTONEG_ENABLE;
  
  	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
  						supported);
  	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
  						advertising);
  
  	return 0;
  }
  
  static void netdev_get_drvinfo(struct net_device *dev,
  			       struct ethtool_drvinfo *info)
  {
  	strlcpy(info->driver, ibmveth_driver_name, sizeof(info->driver));
  	strlcpy(info->version, ibmveth_driver_version, sizeof(info->version));
  }
  
  static netdev_features_t ibmveth_fix_features(struct net_device *dev,
  	netdev_features_t features)
  {
  	/*
  	 * Since the ibmveth firmware interface does not have the
  	 * concept of separate tx/rx checksum offload enable, if rx
  	 * checksum is disabled we also have to disable tx checksum
  	 * offload. Once we disable rx checksum offload, we are no
  	 * longer allowed to send tx buffers that are not properly
  	 * checksummed.
  	 */
  
  	if (!(features & NETIF_F_RXCSUM))
  		features &= ~NETIF_F_CSUM_MASK;
  
  	return features;
  }
  
  static int ibmveth_set_csum_offload(struct net_device *dev, u32 data)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(dev);
  	unsigned long set_attr, clr_attr, ret_attr;
  	unsigned long set_attr6, clr_attr6;
  	long ret, ret4, ret6;
  	int rc1 = 0, rc2 = 0;
  	int restart = 0;
  
  	if (netif_running(dev)) {
  		restart = 1;
  		adapter->pool_config = 1;
  		ibmveth_close(dev);
  		adapter->pool_config = 0;
  	}
  
  	set_attr = 0;
  	clr_attr = 0;
  	set_attr6 = 0;
  	clr_attr6 = 0;
  
  	if (data) {
  		set_attr = IBMVETH_ILLAN_IPV4_TCP_CSUM;
  		set_attr6 = IBMVETH_ILLAN_IPV6_TCP_CSUM;
  	} else {
  		clr_attr = IBMVETH_ILLAN_IPV4_TCP_CSUM;
  		clr_attr6 = IBMVETH_ILLAN_IPV6_TCP_CSUM;
  	}
  
  	ret = h_illan_attributes(adapter->vdev->unit_address, 0, 0, &ret_attr);
  
  	if (ret == H_SUCCESS &&
  	    (ret_attr & IBMVETH_ILLAN_PADDED_PKT_CSUM)) {
  		ret4 = h_illan_attributes(adapter->vdev->unit_address, clr_attr,
  					 set_attr, &ret_attr);
  
  		if (ret4 != H_SUCCESS) {
  			netdev_err(dev, "unable to change IPv4 checksum "
  					"offload settings. %d rc=%ld\n",
  					data, ret4);
  
  			h_illan_attributes(adapter->vdev->unit_address,
  					   set_attr, clr_attr, &ret_attr);
  
  			if (data == 1)
  				dev->features &= ~NETIF_F_IP_CSUM;
  
  		} else {
  			adapter->fw_ipv4_csum_support = data;
  		}
  
  		ret6 = h_illan_attributes(adapter->vdev->unit_address,
  					 clr_attr6, set_attr6, &ret_attr);
  
  		if (ret6 != H_SUCCESS) {
  			netdev_err(dev, "unable to change IPv6 checksum "
  					"offload settings. %d rc=%ld\n",
  					data, ret6);
  
  			h_illan_attributes(adapter->vdev->unit_address,
  					   set_attr6, clr_attr6, &ret_attr);
  
  			if (data == 1)
  				dev->features &= ~NETIF_F_IPV6_CSUM;
  
  		} else
  			adapter->fw_ipv6_csum_support = data;
  
  		if (ret4 == H_SUCCESS || ret6 == H_SUCCESS)
  			adapter->rx_csum = data;
  		else
  			rc1 = -EIO;
  	} else {
  		rc1 = -EIO;
  		netdev_err(dev, "unable to change checksum offload settings."
  				     " %d rc=%ld ret_attr=%lx\n", data, ret,
  				     ret_attr);
  	}
  
  	if (restart)
  		rc2 = ibmveth_open(dev);
  
  	return rc1 ? rc1 : rc2;
  }
  
  static int ibmveth_set_tso(struct net_device *dev, u32 data)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(dev);
  	unsigned long set_attr, clr_attr, ret_attr;
  	long ret1, ret2;
  	int rc1 = 0, rc2 = 0;
  	int restart = 0;
  
  	if (netif_running(dev)) {
  		restart = 1;
  		adapter->pool_config = 1;
  		ibmveth_close(dev);
  		adapter->pool_config = 0;
  	}
  
  	set_attr = 0;
  	clr_attr = 0;
  
  	if (data)
  		set_attr = IBMVETH_ILLAN_LRG_SR_ENABLED;
  	else
  		clr_attr = IBMVETH_ILLAN_LRG_SR_ENABLED;
  
  	ret1 = h_illan_attributes(adapter->vdev->unit_address, 0, 0, &ret_attr);
  
  	if (ret1 == H_SUCCESS && (ret_attr & IBMVETH_ILLAN_LRG_SND_SUPPORT) &&
  	    !old_large_send) {
  		ret2 = h_illan_attributes(adapter->vdev->unit_address, clr_attr,
  					  set_attr, &ret_attr);
  
  		if (ret2 != H_SUCCESS) {
  			netdev_err(dev, "unable to change tso settings. %d rc=%ld\n",
  				   data, ret2);
  
  			h_illan_attributes(adapter->vdev->unit_address,
  					   set_attr, clr_attr, &ret_attr);
  
  			if (data == 1)
  				dev->features &= ~(NETIF_F_TSO | NETIF_F_TSO6);
  			rc1 = -EIO;
  
  		} else {
  			adapter->fw_large_send_support = data;
  			adapter->large_send = data;
  		}
  	} else {
  		/* Older firmware version of large send offload does not
  		 * support tcp6/ipv6
  		 */
  		if (data == 1) {
  			dev->features &= ~NETIF_F_TSO6;
  			netdev_info(dev, "TSO feature requires all partitions to have updated driver");
  		}
  		adapter->large_send = data;
  	}
  
  	if (restart)
  		rc2 = ibmveth_open(dev);
  
  	return rc1 ? rc1 : rc2;
  }
  
  static int ibmveth_set_features(struct net_device *dev,
  	netdev_features_t features)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(dev);
  	int rx_csum = !!(features & NETIF_F_RXCSUM);
  	int large_send = !!(features & (NETIF_F_TSO | NETIF_F_TSO6));
  	int rc1 = 0, rc2 = 0;
  
  	if (rx_csum != adapter->rx_csum) {
  		rc1 = ibmveth_set_csum_offload(dev, rx_csum);
  		if (rc1 && !adapter->rx_csum)
  			dev->features =
  				features & ~(NETIF_F_CSUM_MASK |
  					     NETIF_F_RXCSUM);
  	}
  
  	if (large_send != adapter->large_send) {
  		rc2 = ibmveth_set_tso(dev, large_send);
  		if (rc2 && !adapter->large_send)
  			dev->features =
  				features & ~(NETIF_F_TSO | NETIF_F_TSO6);
  	}
  
  	return rc1 ? rc1 : rc2;
  }
  
  static void ibmveth_get_strings(struct net_device *dev, u32 stringset, u8 *data)
  {
  	int i;
  
  	if (stringset != ETH_SS_STATS)
  		return;
  
  	for (i = 0; i < ARRAY_SIZE(ibmveth_stats); i++, data += ETH_GSTRING_LEN)
  		memcpy(data, ibmveth_stats[i].name, ETH_GSTRING_LEN);
  }
  
  static int ibmveth_get_sset_count(struct net_device *dev, int sset)
  {
  	switch (sset) {
  	case ETH_SS_STATS:
  		return ARRAY_SIZE(ibmveth_stats);
  	default:
  		return -EOPNOTSUPP;
  	}
  }
  
  static void ibmveth_get_ethtool_stats(struct net_device *dev,
  				      struct ethtool_stats *stats, u64 *data)
  {
  	int i;
  	struct ibmveth_adapter *adapter = netdev_priv(dev);
  
  	for (i = 0; i < ARRAY_SIZE(ibmveth_stats); i++)
  		data[i] = IBMVETH_GET_STAT(adapter, ibmveth_stats[i].offset);
  }
  
  static const struct ethtool_ops netdev_ethtool_ops = {
  	.get_drvinfo		= netdev_get_drvinfo,
  	.get_link		= ethtool_op_get_link,
  	.get_strings		= ibmveth_get_strings,
  	.get_sset_count		= ibmveth_get_sset_count,
  	.get_ethtool_stats	= ibmveth_get_ethtool_stats,
  	.get_link_ksettings	= netdev_get_link_ksettings,
  };
  
  static int ibmveth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
  {
  	return -EOPNOTSUPP;
  }
  
  #define page_offset(v) ((unsigned long)(v) & ((1 << 12) - 1))
  
  static int ibmveth_send(struct ibmveth_adapter *adapter,
  			union ibmveth_buf_desc *descs, unsigned long mss)
  {
  	unsigned long correlator;
  	unsigned int retry_count;
  	unsigned long ret;
  
  	/*
  	 * The retry count sets a maximum for the number of broadcast and
  	 * multicast destinations within the system.
  	 */
  	retry_count = 1024;
  	correlator = 0;
  	do {
  		ret = h_send_logical_lan(adapter->vdev->unit_address,
  					     descs[0].desc, descs[1].desc,
  					     descs[2].desc, descs[3].desc,
  					     descs[4].desc, descs[5].desc,
  					     correlator, &correlator, mss,
  					     adapter->fw_large_send_support);
  	} while ((ret == H_BUSY) && (retry_count--));
  
  	if (ret != H_SUCCESS && ret != H_DROPPED) {
  		netdev_err(adapter->netdev, "tx: h_send_logical_lan failed "
  			   "with rc=%ld\n", ret);
  		return 1;
  	}
  
  	return 0;
  }
  
  static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
  				      struct net_device *netdev)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	unsigned int desc_flags;
  	union ibmveth_buf_desc descs[6];
  	int last, i;
  	int force_bounce = 0;
  	dma_addr_t dma_addr;
  	unsigned long mss = 0;
  
  	/* veth doesn't handle frag_list, so linearize the skb.
  	 * When GRO is enabled SKB's can have frag_list.
  	 */
  	if (adapter->is_active_trunk &&
  	    skb_has_frag_list(skb) && __skb_linearize(skb)) {
  		netdev->stats.tx_dropped++;
  		goto out;
  	}
  
  	/*
  	 * veth handles a maximum of 6 segments including the header, so
  	 * we have to linearize the skb if there are more than this.
  	 */
  	if (skb_shinfo(skb)->nr_frags > 5 && __skb_linearize(skb)) {
  		netdev->stats.tx_dropped++;
  		goto out;
  	}
  
  	/* veth can't checksum offload UDP */
  	if (skb->ip_summed == CHECKSUM_PARTIAL &&
  	    ((skb->protocol == htons(ETH_P_IP) &&
  	      ip_hdr(skb)->protocol != IPPROTO_TCP) ||
  	     (skb->protocol == htons(ETH_P_IPV6) &&
  	      ipv6_hdr(skb)->nexthdr != IPPROTO_TCP)) &&
  	    skb_checksum_help(skb)) {
  
  		netdev_err(netdev, "tx: failed to checksum packet\n");
  		netdev->stats.tx_dropped++;
  		goto out;
  	}
  
  	desc_flags = IBMVETH_BUF_VALID;
  
  	if (skb->ip_summed == CHECKSUM_PARTIAL) {
  		unsigned char *buf = skb_transport_header(skb) +
  						skb->csum_offset;
  
  		desc_flags |= (IBMVETH_BUF_NO_CSUM | IBMVETH_BUF_CSUM_GOOD);
  
  		/* Need to zero out the checksum */
  		buf[0] = 0;
  		buf[1] = 0;
  
  		if (skb_is_gso(skb) && adapter->fw_large_send_support)
  			desc_flags |= IBMVETH_BUF_LRG_SND;
  	}
  
  retry_bounce:
  	memset(descs, 0, sizeof(descs));
  
  	/*
  	 * If a linear packet is below the rx threshold then
  	 * copy it into the static bounce buffer. This avoids the
  	 * cost of a TCE insert and remove.
  	 */
  	if (force_bounce || (!skb_is_nonlinear(skb) &&
  				(skb->len < tx_copybreak))) {
  		skb_copy_from_linear_data(skb, adapter->bounce_buffer,
  					  skb->len);
  
  		descs[0].fields.flags_len = desc_flags | skb->len;
  		descs[0].fields.address = adapter->bounce_buffer_dma;
  
  		if (ibmveth_send(adapter, descs, 0)) {
  			adapter->tx_send_failed++;
  			netdev->stats.tx_dropped++;
  		} else {
  			netdev->stats.tx_packets++;
  			netdev->stats.tx_bytes += skb->len;
  		}
  
  		goto out;
  	}
  
  	/* Map the header */
  	dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
  				  skb_headlen(skb), DMA_TO_DEVICE);
  	if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
  		goto map_failed;
  
  	descs[0].fields.flags_len = desc_flags | skb_headlen(skb);
  	descs[0].fields.address = dma_addr;
  
  	/* Map the frags */
  	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
  		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
  
  		dma_addr = skb_frag_dma_map(&adapter->vdev->dev, frag, 0,
  					    skb_frag_size(frag), DMA_TO_DEVICE);
  
  		if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
  			goto map_failed_frags;
  
  		descs[i+1].fields.flags_len = desc_flags | skb_frag_size(frag);
  		descs[i+1].fields.address = dma_addr;
  	}
  
  	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_is_gso(skb)) {
  		if (adapter->fw_large_send_support) {
  			mss = (unsigned long)skb_shinfo(skb)->gso_size;
  			adapter->tx_large_packets++;
  		} else if (!skb_is_gso_v6(skb)) {
  			/* Put -1 in the IP checksum to tell phyp it
  			 * is a largesend packet. Put the mss in
  			 * the TCP checksum.
  			 */
  			ip_hdr(skb)->check = 0xffff;
  			tcp_hdr(skb)->check =
  				cpu_to_be16(skb_shinfo(skb)->gso_size);
  			adapter->tx_large_packets++;
  		}
  	}
  
  	if (ibmveth_send(adapter, descs, mss)) {
  		adapter->tx_send_failed++;
  		netdev->stats.tx_dropped++;
  	} else {
  		netdev->stats.tx_packets++;
  		netdev->stats.tx_bytes += skb->len;
  	}
  
  	dma_unmap_single(&adapter->vdev->dev,
  			 descs[0].fields.address,
  			 descs[0].fields.flags_len & IBMVETH_BUF_LEN_MASK,
  			 DMA_TO_DEVICE);
  
  	for (i = 1; i < skb_shinfo(skb)->nr_frags + 1; i++)
  		dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address,
  			       descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK,
  			       DMA_TO_DEVICE);
  
  out:
  	dev_consume_skb_any(skb);
  	return NETDEV_TX_OK;
  
  map_failed_frags:
  	last = i+1;
  	for (i = 0; i < last; i++)
  		dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address,
  			       descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK,
  			       DMA_TO_DEVICE);
  
  map_failed:
  	if (!firmware_has_feature(FW_FEATURE_CMO))
  		netdev_err(netdev, "tx: unable to map xmit buffer\n");
  	adapter->tx_map_failed++;
  	if (skb_linearize(skb)) {
  		netdev->stats.tx_dropped++;
  		goto out;
  	}
  	force_bounce = 1;
  	goto retry_bounce;
  }
  
  static void ibmveth_rx_mss_helper(struct sk_buff *skb, u16 mss, int lrg_pkt)
  {
  	struct tcphdr *tcph;
  	int offset = 0;
  	int hdr_len;
  
  	/* only TCP packets will be aggregated */
  	if (skb->protocol == htons(ETH_P_IP)) {
  		struct iphdr *iph = (struct iphdr *)skb->data;
  
  		if (iph->protocol == IPPROTO_TCP) {
  			offset = iph->ihl * 4;
  			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
  		} else {
  			return;
  		}
  	} else if (skb->protocol == htons(ETH_P_IPV6)) {
  		struct ipv6hdr *iph6 = (struct ipv6hdr *)skb->data;
  
  		if (iph6->nexthdr == IPPROTO_TCP) {
  			offset = sizeof(struct ipv6hdr);
  			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
  		} else {
  			return;
  		}
  	} else {
  		return;
  	}
  	/* if mss is not set through Large Packet bit/mss in rx buffer,
  	 * expect that the mss will be written to the tcp header checksum.
  	 */
  	tcph = (struct tcphdr *)(skb->data + offset);
  	if (lrg_pkt) {
  		skb_shinfo(skb)->gso_size = mss;
  	} else if (offset) {
  		skb_shinfo(skb)->gso_size = ntohs(tcph->check);
  		tcph->check = 0;
  	}
  
  	if (skb_shinfo(skb)->gso_size) {
  		hdr_len = offset + tcph->doff * 4;
  		skb_shinfo(skb)->gso_segs =
  				DIV_ROUND_UP(skb->len - hdr_len,
  					     skb_shinfo(skb)->gso_size);
  	}
  }
  
  static void ibmveth_rx_csum_helper(struct sk_buff *skb,
  				   struct ibmveth_adapter *adapter)
  {
  	struct iphdr *iph = NULL;
  	struct ipv6hdr *iph6 = NULL;
  	__be16 skb_proto = 0;
  	u16 iphlen = 0;
  	u16 iph_proto = 0;
  	u16 tcphdrlen = 0;
  
  	skb_proto = be16_to_cpu(skb->protocol);
  
  	if (skb_proto == ETH_P_IP) {
  		iph = (struct iphdr *)skb->data;
  
  		/* If the IP checksum is not offloaded and if the packet
  		 *  is large send, the checksum must be rebuilt.
  		 */
  		if (iph->check == 0xffff) {
  			iph->check = 0;
  			iph->check = ip_fast_csum((unsigned char *)iph,
  						  iph->ihl);
  		}
  
  		iphlen = iph->ihl * 4;
  		iph_proto = iph->protocol;
  	} else if (skb_proto == ETH_P_IPV6) {
  		iph6 = (struct ipv6hdr *)skb->data;
  		iphlen = sizeof(struct ipv6hdr);
  		iph_proto = iph6->nexthdr;
  	}
  
  	/* In OVS environment, when a flow is not cached, specifically for a
  	 * new TCP connection, the first packet information is passed up
  	 * the user space for finding a flow. During this process, OVS computes
  	 * checksum on the first packet when CHECKSUM_PARTIAL flag is set.
  	 *
  	 * Given that we zeroed out TCP checksum field in transmit path
  	 * (refer ibmveth_start_xmit routine) as we set "no checksum bit",
  	 * OVS computed checksum will be incorrect w/o TCP pseudo checksum
  	 * in the packet. This leads to OVS dropping the packet and hence
  	 * TCP retransmissions are seen.
  	 *
  	 * So, re-compute TCP pseudo header checksum.
  	 */
  	if (iph_proto == IPPROTO_TCP && adapter->is_active_trunk) {
  		struct tcphdr *tcph = (struct tcphdr *)(skb->data + iphlen);
  
  		tcphdrlen = skb->len - iphlen;
  
  		/* Recompute TCP pseudo header checksum */
  		if (skb_proto == ETH_P_IP)
  			tcph->check = ~csum_tcpudp_magic(iph->saddr,
  					iph->daddr, tcphdrlen, iph_proto, 0);
  		else if (skb_proto == ETH_P_IPV6)
  			tcph->check = ~csum_ipv6_magic(&iph6->saddr,
  					&iph6->daddr, tcphdrlen, iph_proto, 0);
  
  		/* Setup SKB fields for checksum offload */
  		skb_partial_csum_set(skb, iphlen,
  				     offsetof(struct tcphdr, check));
  		skb_reset_network_header(skb);
  	}
  }
  
  static int ibmveth_poll(struct napi_struct *napi, int budget)
  {
  	struct ibmveth_adapter *adapter =
  			container_of(napi, struct ibmveth_adapter, napi);
  	struct net_device *netdev = adapter->netdev;
  	int frames_processed = 0;
  	unsigned long lpar_rc;
  	u16 mss = 0;
  
  restart_poll:
  	while (frames_processed < budget) {
  		if (!ibmveth_rxq_pending_buffer(adapter))
  			break;
  
  		smp_rmb();
  		if (!ibmveth_rxq_buffer_valid(adapter)) {
  			wmb(); /* suggested by larson1 */
  			adapter->rx_invalid_buffer++;
  			netdev_dbg(netdev, "recycling invalid buffer\n");
  			ibmveth_rxq_recycle_buffer(adapter);
  		} else {
  			struct sk_buff *skb, *new_skb;
  			int length = ibmveth_rxq_frame_length(adapter);
  			int offset = ibmveth_rxq_frame_offset(adapter);
  			int csum_good = ibmveth_rxq_csum_good(adapter);
  			int lrg_pkt = ibmveth_rxq_large_packet(adapter);
  
  			skb = ibmveth_rxq_get_buffer(adapter);
  
  			/* if the large packet bit is set in the rx queue
  			 * descriptor, the mss will be written by PHYP eight
  			 * bytes from the start of the rx buffer, which is
  			 * skb->data at this stage
  			 */
  			if (lrg_pkt) {
  				__be64 *rxmss = (__be64 *)(skb->data + 8);
  
  				mss = (u16)be64_to_cpu(*rxmss);
  			}
  
  			new_skb = NULL;
  			if (length < rx_copybreak)
  				new_skb = netdev_alloc_skb(netdev, length);
  
  			if (new_skb) {
  				skb_copy_to_linear_data(new_skb,
  							skb->data + offset,
  							length);
  				if (rx_flush)
  					ibmveth_flush_buffer(skb->data,
  						length + offset);
  				if (!ibmveth_rxq_recycle_buffer(adapter))
  					kfree_skb(skb);
  				skb = new_skb;
  			} else {
  				ibmveth_rxq_harvest_buffer(adapter);
  				skb_reserve(skb, offset);
  			}
  
  			skb_put(skb, length);
  			skb->protocol = eth_type_trans(skb, netdev);
  
  			if (csum_good) {
  				skb->ip_summed = CHECKSUM_UNNECESSARY;
  				ibmveth_rx_csum_helper(skb, adapter);
  			}
  
  			if (length > netdev->mtu + ETH_HLEN) {
  				ibmveth_rx_mss_helper(skb, mss, lrg_pkt);
  				adapter->rx_large_packets++;
  			}
  
  			napi_gro_receive(napi, skb);	/* send it up */
  
  			netdev->stats.rx_packets++;
  			netdev->stats.rx_bytes += length;
  			frames_processed++;
  		}
  	}
  
  	ibmveth_replenish_task(adapter);
  
  	if (frames_processed < budget) {
  		napi_complete_done(napi, frames_processed);
  
  		/* We think we are done - reenable interrupts,
  		 * then check once more to make sure we are done.
  		 */
  		lpar_rc = h_vio_signal(adapter->vdev->unit_address,
  				       VIO_IRQ_ENABLE);
  
  		BUG_ON(lpar_rc != H_SUCCESS);
  
  		if (ibmveth_rxq_pending_buffer(adapter) &&
  		    napi_reschedule(napi)) {
  			lpar_rc = h_vio_signal(adapter->vdev->unit_address,
  					       VIO_IRQ_DISABLE);
  			goto restart_poll;
  		}
  	}
  
  	return frames_processed;
  }
  
  static irqreturn_t ibmveth_interrupt(int irq, void *dev_instance)
  {
  	struct net_device *netdev = dev_instance;
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	unsigned long lpar_rc;
  
  	if (napi_schedule_prep(&adapter->napi)) {
  		lpar_rc = h_vio_signal(adapter->vdev->unit_address,
  				       VIO_IRQ_DISABLE);
  		BUG_ON(lpar_rc != H_SUCCESS);
  		__napi_schedule(&adapter->napi);
  	}
  	return IRQ_HANDLED;
  }
  
  static void ibmveth_set_multicast_list(struct net_device *netdev)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	unsigned long lpar_rc;
  
  	if ((netdev->flags & IFF_PROMISC) ||
  	    (netdev_mc_count(netdev) > adapter->mcastFilterSize)) {
  		lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
  					   IbmVethMcastEnableRecv |
  					   IbmVethMcastDisableFiltering,
  					   0);
  		if (lpar_rc != H_SUCCESS) {
  			netdev_err(netdev, "h_multicast_ctrl rc=%ld when "
  				   "entering promisc mode\n", lpar_rc);
  		}
  	} else {
  		struct netdev_hw_addr *ha;
  		/* clear the filter table & disable filtering */
  		lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
  					   IbmVethMcastEnableRecv |
  					   IbmVethMcastDisableFiltering |
  					   IbmVethMcastClearFilterTable,
  					   0);
  		if (lpar_rc != H_SUCCESS) {
  			netdev_err(netdev, "h_multicast_ctrl rc=%ld when "
  				   "attempting to clear filter table\n",
  				   lpar_rc);
  		}
  		/* add the addresses to the filter table */
  		netdev_for_each_mc_addr(ha, netdev) {
  			/* add the multicast address to the filter table */
  			u64 mcast_addr;
  			mcast_addr = ibmveth_encode_mac_addr(ha->addr);
  			lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
  						   IbmVethMcastAddFilter,
  						   mcast_addr);
  			if (lpar_rc != H_SUCCESS) {
  				netdev_err(netdev, "h_multicast_ctrl rc=%ld "
  					   "when adding an entry to the filter "
  					   "table\n", lpar_rc);
  			}
  		}
  
  		/* re-enable filtering */
  		lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
  					   IbmVethMcastEnableFiltering,
  					   0);
  		if (lpar_rc != H_SUCCESS) {
  			netdev_err(netdev, "h_multicast_ctrl rc=%ld when "
  				   "enabling filtering\n", lpar_rc);
  		}
  	}
  }
  
  static int ibmveth_change_mtu(struct net_device *dev, int new_mtu)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(dev);
  	struct vio_dev *viodev = adapter->vdev;
  	int new_mtu_oh = new_mtu + IBMVETH_BUFF_OH;
  	int i, rc;
  	int need_restart = 0;
  
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
  		if (new_mtu_oh <= adapter->rx_buff_pool[i].buff_size)
  			break;
  
  	if (i == IBMVETH_NUM_BUFF_POOLS)
  		return -EINVAL;
  
  	/* Deactivate all the buffer pools so that the next loop can activate
  	   only the buffer pools necessary to hold the new MTU */
  	if (netif_running(adapter->netdev)) {
  		need_restart = 1;
  		adapter->pool_config = 1;
  		ibmveth_close(adapter->netdev);
  		adapter->pool_config = 0;
  	}
  
  	/* Look for an active buffer pool that can hold the new MTU */
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
  		adapter->rx_buff_pool[i].active = 1;
  
  		if (new_mtu_oh <= adapter->rx_buff_pool[i].buff_size) {
  			dev->mtu = new_mtu;
  			vio_cmo_set_dev_desired(viodev,
  						ibmveth_get_desired_dma
  						(viodev));
  			if (need_restart) {
  				return ibmveth_open(adapter->netdev);
  			}
  			return 0;
  		}
  	}
  
  	if (need_restart && (rc = ibmveth_open(adapter->netdev)))
  		return rc;
  
  	return -EINVAL;
  }
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
  static void ibmveth_poll_controller(struct net_device *dev)
  {
  	ibmveth_replenish_task(netdev_priv(dev));
  	ibmveth_interrupt(dev->irq, dev);
  }
  #endif
  
  /**
   * ibmveth_get_desired_dma - Calculate IO memory desired by the driver
   *
   * @vdev: struct vio_dev for the device whose desired IO mem is to be returned
   *
   * Return value:
   *	Number of bytes of IO data the driver will need to perform well.
   */
  static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev)
  {
  	struct net_device *netdev = dev_get_drvdata(&vdev->dev);
  	struct ibmveth_adapter *adapter;
  	struct iommu_table *tbl;
  	unsigned long ret;
  	int i;
  	int rxqentries = 1;
  
  	tbl = get_iommu_table_base(&vdev->dev);
  
  	/* netdev inits at probe time along with the structures we need below*/
  	if (netdev == NULL)
  		return IOMMU_PAGE_ALIGN(IBMVETH_IO_ENTITLEMENT_DEFAULT, tbl);
  
  	adapter = netdev_priv(netdev);
  
  	ret = IBMVETH_BUFF_LIST_SIZE + IBMVETH_FILT_LIST_SIZE;
  	ret += IOMMU_PAGE_ALIGN(netdev->mtu, tbl);
  
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
  		/* add the size of the active receive buffers */
  		if (adapter->rx_buff_pool[i].active)
  			ret +=
  			    adapter->rx_buff_pool[i].size *
  			    IOMMU_PAGE_ALIGN(adapter->rx_buff_pool[i].
  					     buff_size, tbl);
  		rxqentries += adapter->rx_buff_pool[i].size;
  	}
  	/* add the size of the receive queue entries */
  	ret += IOMMU_PAGE_ALIGN(
  		rxqentries * sizeof(struct ibmveth_rx_q_entry), tbl);
  
  	return ret;
  }
  
  static int ibmveth_set_mac_addr(struct net_device *dev, void *p)
  {
  	struct ibmveth_adapter *adapter = netdev_priv(dev);
  	struct sockaddr *addr = p;
  	u64 mac_address;
  	int rc;
  
  	if (!is_valid_ether_addr(addr->sa_data))
  		return -EADDRNOTAVAIL;
  
  	mac_address = ibmveth_encode_mac_addr(addr->sa_data);
  	rc = h_change_logical_lan_mac(adapter->vdev->unit_address, mac_address);
  	if (rc) {
  		netdev_err(adapter->netdev, "h_change_logical_lan_mac failed with rc=%d\n", rc);
  		return rc;
  	}
  
  	ether_addr_copy(dev->dev_addr, addr->sa_data);
  
  	return 0;
  }
  
  static const struct net_device_ops ibmveth_netdev_ops = {
  	.ndo_open		= ibmveth_open,
  	.ndo_stop		= ibmveth_close,
  	.ndo_start_xmit		= ibmveth_start_xmit,
  	.ndo_set_rx_mode	= ibmveth_set_multicast_list,
  	.ndo_do_ioctl		= ibmveth_ioctl,
  	.ndo_change_mtu		= ibmveth_change_mtu,
  	.ndo_fix_features	= ibmveth_fix_features,
  	.ndo_set_features	= ibmveth_set_features,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_set_mac_address    = ibmveth_set_mac_addr,
  #ifdef CONFIG_NET_POLL_CONTROLLER
  	.ndo_poll_controller	= ibmveth_poll_controller,
  #endif
  };
  
  static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
  {
  	int rc, i, mac_len;
  	struct net_device *netdev;
  	struct ibmveth_adapter *adapter;
  	unsigned char *mac_addr_p;
  	unsigned int *mcastFilterSize_p;
  	long ret;
  	unsigned long ret_attr;
  
  	dev_dbg(&dev->dev, "entering ibmveth_probe for UA 0x%x\n",
  		dev->unit_address);
  
  	mac_addr_p = (unsigned char *)vio_get_attribute(dev, VETH_MAC_ADDR,
  							&mac_len);
  	if (!mac_addr_p) {
  		dev_err(&dev->dev, "Can't find VETH_MAC_ADDR attribute\n");
  		return -EINVAL;
  	}
  	/* Workaround for old/broken pHyp */
  	if (mac_len == 8)
  		mac_addr_p += 2;
  	else if (mac_len != 6) {
  		dev_err(&dev->dev, "VETH_MAC_ADDR attribute wrong len %d\n",
  			mac_len);
  		return -EINVAL;
  	}
  
  	mcastFilterSize_p = (unsigned int *)vio_get_attribute(dev,
  						VETH_MCAST_FILTER_SIZE, NULL);
  	if (!mcastFilterSize_p) {
  		dev_err(&dev->dev, "Can't find VETH_MCAST_FILTER_SIZE "
  			"attribute\n");
  		return -EINVAL;
  	}
  
  	netdev = alloc_etherdev(sizeof(struct ibmveth_adapter));
  
  	if (!netdev)
  		return -ENOMEM;
  
  	adapter = netdev_priv(netdev);
  	dev_set_drvdata(&dev->dev, netdev);
  
  	adapter->vdev = dev;
  	adapter->netdev = netdev;
  	adapter->mcastFilterSize = *mcastFilterSize_p;
  	adapter->pool_config = 0;
  
  	netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);
  
  	netdev->irq = dev->irq;
  	netdev->netdev_ops = &ibmveth_netdev_ops;
  	netdev->ethtool_ops = &netdev_ethtool_ops;
  	SET_NETDEV_DEV(netdev, &dev->dev);
  	netdev->hw_features = NETIF_F_SG;
  	if (vio_get_attribute(dev, "ibm,illan-options", NULL) != NULL) {
  		netdev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
  				       NETIF_F_RXCSUM;
  	}
  
  	netdev->features |= netdev->hw_features;
  
  	ret = h_illan_attributes(adapter->vdev->unit_address, 0, 0, &ret_attr);
  
  	/* If running older firmware, TSO should not be enabled by default */
  	if (ret == H_SUCCESS && (ret_attr & IBMVETH_ILLAN_LRG_SND_SUPPORT) &&
  	    !old_large_send) {
  		netdev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;
  		netdev->features |= netdev->hw_features;
  	} else {
  		netdev->hw_features |= NETIF_F_TSO;
  	}
  
  	adapter->is_active_trunk = false;
  	if (ret == H_SUCCESS && (ret_attr & IBMVETH_ILLAN_ACTIVE_TRUNK)) {
  		adapter->is_active_trunk = true;
  		netdev->hw_features |= NETIF_F_FRAGLIST;
  		netdev->features |= NETIF_F_FRAGLIST;
  	}
  
  	netdev->min_mtu = IBMVETH_MIN_MTU;
  	netdev->max_mtu = ETH_MAX_MTU;
  
  	memcpy(netdev->dev_addr, mac_addr_p, ETH_ALEN);
  
  	if (firmware_has_feature(FW_FEATURE_CMO))
  		memcpy(pool_count, pool_count_cmo, sizeof(pool_count));
  
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
  		struct kobject *kobj = &adapter->rx_buff_pool[i].kobj;
  		int error;
  
  		ibmveth_init_buffer_pool(&adapter->rx_buff_pool[i], i,
  					 pool_count[i], pool_size[i],
  					 pool_active[i]);
  		error = kobject_init_and_add(kobj, &ktype_veth_pool,
  					     &dev->dev.kobj, "pool%d", i);
  		if (!error)
  			kobject_uevent(kobj, KOBJ_ADD);
  	}
  
  	netdev_dbg(netdev, "adapter @ 0x%p\n", adapter);
  	netdev_dbg(netdev, "registering netdev...\n");
  
  	ibmveth_set_features(netdev, netdev->features);
  
  	rc = register_netdev(netdev);
  
  	if (rc) {
  		netdev_dbg(netdev, "failed to register netdev rc=%d\n", rc);
  		free_netdev(netdev);
  		return rc;
  	}
  
  	netdev_dbg(netdev, "registered\n");
  
  	return 0;
  }
  
  static int ibmveth_remove(struct vio_dev *dev)
  {
  	struct net_device *netdev = dev_get_drvdata(&dev->dev);
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	int i;
  
  	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
  		kobject_put(&adapter->rx_buff_pool[i].kobj);
  
  	unregister_netdev(netdev);
  
  	free_netdev(netdev);
  	dev_set_drvdata(&dev->dev, NULL);
  
  	return 0;
  }
  
  static struct attribute veth_active_attr;
  static struct attribute veth_num_attr;
  static struct attribute veth_size_attr;
  
  static ssize_t veth_pool_show(struct kobject *kobj,
  			      struct attribute *attr, char *buf)
  {
  	struct ibmveth_buff_pool *pool = container_of(kobj,
  						      struct ibmveth_buff_pool,
  						      kobj);
  
  	if (attr == &veth_active_attr)
  		return sprintf(buf, "%d\n", pool->active);
  	else if (attr == &veth_num_attr)
  		return sprintf(buf, "%d\n", pool->size);
  	else if (attr == &veth_size_attr)
  		return sprintf(buf, "%d\n", pool->buff_size);
  	return 0;
  }
  
  static ssize_t veth_pool_store(struct kobject *kobj, struct attribute *attr,
  			       const char *buf, size_t count)
  {
  	struct ibmveth_buff_pool *pool = container_of(kobj,
  						      struct ibmveth_buff_pool,
  						      kobj);
  	struct net_device *netdev = dev_get_drvdata(
  	    container_of(kobj->parent, struct device, kobj));
  	struct ibmveth_adapter *adapter = netdev_priv(netdev);
  	long value = simple_strtol(buf, NULL, 10);
  	long rc;
  
  	if (attr == &veth_active_attr) {
  		if (value && !pool->active) {
  			if (netif_running(netdev)) {
  				if (ibmveth_alloc_buffer_pool(pool)) {
  					netdev_err(netdev,
  						   "unable to alloc pool\n");
  					return -ENOMEM;
  				}
  				pool->active = 1;
  				adapter->pool_config = 1;
  				ibmveth_close(netdev);
  				adapter->pool_config = 0;
  				if ((rc = ibmveth_open(netdev)))
  					return rc;
  			} else {
  				pool->active = 1;
  			}
  		} else if (!value && pool->active) {
  			int mtu = netdev->mtu + IBMVETH_BUFF_OH;
  			int i;
  			/* Make sure there is a buffer pool with buffers that
  			   can hold a packet of the size of the MTU */
  			for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
  				if (pool == &adapter->rx_buff_pool[i])
  					continue;
  				if (!adapter->rx_buff_pool[i].active)
  					continue;
  				if (mtu <= adapter->rx_buff_pool[i].buff_size)
  					break;
  			}
  
  			if (i == IBMVETH_NUM_BUFF_POOLS) {
  				netdev_err(netdev, "no active pool >= MTU\n");
  				return -EPERM;
  			}
  
  			if (netif_running(netdev)) {
  				adapter->pool_config = 1;
  				ibmveth_close(netdev);
  				pool->active = 0;
  				adapter->pool_config = 0;
  				if ((rc = ibmveth_open(netdev)))
  					return rc;
  			}
  			pool->active = 0;
  		}
  	} else if (attr == &veth_num_attr) {
  		if (value <= 0 || value > IBMVETH_MAX_POOL_COUNT) {
  			return -EINVAL;
  		} else {
  			if (netif_running(netdev)) {
  				adapter->pool_config = 1;
  				ibmveth_close(netdev);
  				adapter->pool_config = 0;
  				pool->size = value;
  				if ((rc = ibmveth_open(netdev)))
  					return rc;
  			} else {
  				pool->size = value;
  			}
  		}
  	} else if (attr == &veth_size_attr) {
  		if (value <= IBMVETH_BUFF_OH || value > IBMVETH_MAX_BUF_SIZE) {
  			return -EINVAL;
  		} else {
  			if (netif_running(netdev)) {
  				adapter->pool_config = 1;
  				ibmveth_close(netdev);
  				adapter->pool_config = 0;
  				pool->buff_size = value;
  				if ((rc = ibmveth_open(netdev)))
  					return rc;
  			} else {
  				pool->buff_size = value;
  			}
  		}
  	}
  
  	/* kick the interrupt handler to allocate/deallocate pools */
  	ibmveth_interrupt(netdev->irq, netdev);
  	return count;
  }
  
  
  #define ATTR(_name, _mode)				\
  	struct attribute veth_##_name##_attr = {	\
  	.name = __stringify(_name), .mode = _mode,	\
  	};
  
  static ATTR(active, 0644);
  static ATTR(num, 0644);
  static ATTR(size, 0644);
  
  static struct attribute *veth_pool_attrs[] = {
  	&veth_active_attr,
  	&veth_num_attr,
  	&veth_size_attr,
  	NULL,
  };
  
  static const struct sysfs_ops veth_pool_ops = {
  	.show   = veth_pool_show,
  	.store  = veth_pool_store,
  };
  
  static struct kobj_type ktype_veth_pool = {
  	.release        = NULL,
  	.sysfs_ops      = &veth_pool_ops,
  	.default_attrs  = veth_pool_attrs,
  };
  
  static int ibmveth_resume(struct device *dev)
  {
  	struct net_device *netdev = dev_get_drvdata(dev);
  	ibmveth_interrupt(netdev->irq, netdev);
  	return 0;
  }
  
  static struct vio_device_id ibmveth_device_table[] = {
  	{ "network", "IBM,l-lan"},
  	{ "", "" }
  };
  MODULE_DEVICE_TABLE(vio, ibmveth_device_table);
  
  static const struct dev_pm_ops ibmveth_pm_ops = {
  	.resume = ibmveth_resume
  };
  
  static struct vio_driver ibmveth_driver = {
  	.id_table	= ibmveth_device_table,
  	.probe		= ibmveth_probe,
  	.remove		= ibmveth_remove,
  	.get_desired_dma = ibmveth_get_desired_dma,
  	.name		= ibmveth_driver_name,
  	.pm		= &ibmveth_pm_ops,
  };
  
  static int __init ibmveth_module_init(void)
  {
  	printk(KERN_DEBUG "%s: %s %s\n", ibmveth_driver_name,
  	       ibmveth_driver_string, ibmveth_driver_version);
  
  	return vio_register_driver(&ibmveth_driver);
  }
  
  static void __exit ibmveth_module_exit(void)
  {
  	vio_unregister_driver(&ibmveth_driver);
  }
  
  module_init(ibmveth_module_init);
  module_exit(ibmveth_module_exit);
  