/*
 * Copyright 2015 Amazon.com, Inc. or its affiliates.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#ifdef CONFIG_RFS_ACCEL
#include <linux/cpu_rmap.h>
#endif /* CONFIG_RFS_ACCEL */
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/numa.h>
#include <linux/pci.h>
#include <linux/utsname.h>
#include <linux/version.h>
#include <linux/vmalloc.h>
#include <net/ip.h>

#include "ena_netdev.h"
#include "ena_pci_id_tbl.h"

static char version[] = DEVICE_NAME " v" DRV_MODULE_VERSION "\n";

MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
MODULE_DESCRIPTION(DEVICE_NAME);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);

/* Time in jiffies before concluding the transmitter is hung. */
#define TX_TIMEOUT  (5 * HZ)

#define ENA_NAPI_BUDGET 64

#define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_IFUP | \
                NETIF_MSG_TX_DONE | NETIF_MSG_TX_ERR | NETIF_MSG_RX_ERR)
static int debug = -1;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");

static struct ena_aenq_handlers aenq_handlers;

static struct workqueue_struct *ena_wq;

MODULE_DEVICE_TABLE(pci, ena_pci_tbl);

static int ena_rss_init_default(struct ena_adapter *adapter);
static void check_for_admin_com_state(struct ena_adapter *adapter);
static void ena_destroy_device(struct ena_adapter *adapter, bool graceful);
static int ena_restore_device(struct ena_adapter *adapter);

static void ena_tx_timeout(struct net_device *dev)
{
        struct ena_adapter *adapter = netdev_priv(dev);

        /* Change the state of the device to trigger reset
         * Check that we are not in the middle or a trigger already
         */

        if (test_and_set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags))
                return;

        adapter->reset_reason = ENA_REGS_RESET_OS_NETDEV_WD;
        u64_stats_update_begin(&adapter->syncp);
        adapter->dev_stats.tx_timeout++;
        u64_stats_update_end(&adapter->syncp);

        netif_err(adapter, tx_err, dev, "Transmit time out\n");
}

static void update_rx_ring_mtu(struct ena_adapter *adapter, int mtu)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                adapter->rx_ring[i].mtu = mtu;
}

static int ena_change_mtu(struct net_device *dev, int new_mtu)
{
        struct ena_adapter *adapter = netdev_priv(dev);
        int ret;

        ret = ena_com_set_dev_mtu(adapter->ena_dev, new_mtu);
        if (!ret) {
                netif_dbg(adapter, drv, dev, "set MTU to %d\n", new_mtu);
                update_rx_ring_mtu(adapter, new_mtu);
                dev->mtu = new_mtu;
        } else {
                netif_err(adapter, drv, dev, "Failed to set MTU to %d\n",
                          new_mtu);
        }

        return ret;
}

static int ena_init_rx_cpu_rmap(struct ena_adapter *adapter)
{
#ifdef CONFIG_RFS_ACCEL
        u32 i;
        int rc;

        adapter->netdev->rx_cpu_rmap = alloc_irq_cpu_rmap(adapter->num_queues);
        if (!adapter->netdev->rx_cpu_rmap)
                return -ENOMEM;
        for (i = 0; i < adapter->num_queues; i++) {
                int irq_idx = ENA_IO_IRQ_IDX(i);

                rc = irq_cpu_rmap_add(adapter->netdev->rx_cpu_rmap,
                                      pci_irq_vector(adapter->pdev, irq_idx));
                if (rc) {
                        free_irq_cpu_rmap(adapter->netdev->rx_cpu_rmap);
                        adapter->netdev->rx_cpu_rmap = NULL;
                        return rc;
                }
        }
#endif /* CONFIG_RFS_ACCEL */
        return 0;
}

static void ena_init_io_rings_common(struct ena_adapter *adapter,
                                     struct ena_ring *ring, u16 qid)
{
        ring->qid = qid;
        ring->pdev = adapter->pdev;
        ring->dev = &adapter->pdev->dev;
        ring->netdev = adapter->netdev;
        ring->napi = &adapter->ena_napi[qid].napi;
        ring->adapter = adapter;
        ring->ena_dev = adapter->ena_dev;
        ring->per_napi_packets = 0;
        ring->per_napi_bytes = 0;
        ring->cpu = 0;
        ring->first_interrupt = false;
        ring->no_interrupt_event_cnt = 0;
        u64_stats_init(&ring->syncp);
}

static void ena_init_io_rings(struct ena_adapter *adapter)
{
        struct ena_com_dev *ena_dev;
        struct ena_ring *txr, *rxr;
        int i;

        ena_dev = adapter->ena_dev;

        for (i = 0; i < adapter->num_queues; i++) {
                txr = &adapter->tx_ring[i];
                rxr = &adapter->rx_ring[i];

                /* TX/RX common ring state */
                ena_init_io_rings_common(adapter, txr, i);
                ena_init_io_rings_common(adapter, rxr, i);

                /* TX specific ring state */
                txr->ring_size = adapter->requested_tx_ring_size;
                txr->tx_max_header_size = ena_dev->tx_max_header_size;
                txr->tx_mem_queue_type = ena_dev->tx_mem_queue_type;
                txr->sgl_size = adapter->max_tx_sgl_size;
                txr->smoothed_interval =
                        ena_com_get_nonadaptive_moderation_interval_tx(ena_dev);

                /* RX specific ring state */
                rxr->ring_size = adapter->requested_rx_ring_size;
                rxr->rx_copybreak = adapter->rx_copybreak;
                rxr->sgl_size = adapter->max_rx_sgl_size;
                rxr->smoothed_interval =
                        ena_com_get_nonadaptive_moderation_interval_rx(ena_dev);
                rxr->empty_rx_queue = 0;
        }
}

/* ena_setup_tx_resources - allocate I/O Tx resources (Descriptors)
 * @adapter: network interface device structure
 * @qid: queue index
 *
 * Return 0 on success, negative on failure
 */
static int ena_setup_tx_resources(struct ena_adapter *adapter, int qid)
{
        struct ena_ring *tx_ring = &adapter->tx_ring[qid];
        struct ena_irq *ena_irq = &adapter->irq_tbl[ENA_IO_IRQ_IDX(qid)];
        int size, i, node;

        if (tx_ring->tx_buffer_info) {
                netif_err(adapter, ifup,
                          adapter->netdev, "tx_buffer_info info is not NULL");
                return -EEXIST;
        }

        size = sizeof(struct ena_tx_buffer) * tx_ring->ring_size;
        node = cpu_to_node(ena_irq->cpu);

        tx_ring->tx_buffer_info = vzalloc_node(size, node);
        if (!tx_ring->tx_buffer_info) {
                tx_ring->tx_buffer_info = vzalloc(size);
                if (!tx_ring->tx_buffer_info)
                        goto err_tx_buffer_info;
        }

        size = sizeof(u16) * tx_ring->ring_size;
        tx_ring->free_ids = vzalloc_node(size, node);
        if (!tx_ring->free_ids) {
                tx_ring->free_ids = vzalloc(size);
                if (!tx_ring->free_ids)
                        goto err_tx_free_ids;
        }

        size = tx_ring->tx_max_header_size;
        tx_ring->push_buf_intermediate_buf = vzalloc_node(size, node);
        if (!tx_ring->push_buf_intermediate_buf) {
                tx_ring->push_buf_intermediate_buf = vzalloc(size);
                if (!tx_ring->push_buf_intermediate_buf)
                        goto err_push_buf_intermediate_buf;
        }

        /* Req id ring for TX out of order completions */
        for (i = 0; i < tx_ring->ring_size; i++)
                tx_ring->free_ids[i] = i;

        /* Reset tx statistics */
        memset(&tx_ring->tx_stats, 0x0, sizeof(tx_ring->tx_stats));

        tx_ring->next_to_use = 0;
        tx_ring->next_to_clean = 0;
        tx_ring->cpu = ena_irq->cpu;
        return 0;

err_push_buf_intermediate_buf:
        vfree(tx_ring->free_ids);
        tx_ring->free_ids = NULL;
err_tx_free_ids:
        vfree(tx_ring->tx_buffer_info);
        tx_ring->tx_buffer_info = NULL;
err_tx_buffer_info:
        return -ENOMEM;
}

/* ena_free_tx_resources - Free I/O Tx Resources per Queue
 * @adapter: network interface device structure
 * @qid: queue index
 *
 * Free all transmit software resources
 */
static void ena_free_tx_resources(struct ena_adapter *adapter, int qid)
{
        struct ena_ring *tx_ring = &adapter->tx_ring[qid];

        vfree(tx_ring->tx_buffer_info);
        tx_ring->tx_buffer_info = NULL;

        vfree(tx_ring->free_ids);
        tx_ring->free_ids = NULL;

        vfree(tx_ring->push_buf_intermediate_buf);
        tx_ring->push_buf_intermediate_buf = NULL;
}

/* ena_setup_all_tx_resources - allocate I/O Tx queues resources for All queues
 * @adapter: private structure
 *
 * Return 0 on success, negative on failure
 */
static int ena_setup_all_tx_resources(struct ena_adapter *adapter)
{
        int i, rc = 0;

        for (i = 0; i < adapter->num_queues; i++) {
                rc = ena_setup_tx_resources(adapter, i);
                if (rc)
                        goto err_setup_tx;
        }

        return 0;

err_setup_tx:

        netif_err(adapter, ifup, adapter->netdev,
                  "Tx queue %d: allocation failed\n", i);

        /* rewind the index freeing the rings as we go */
        while (i--)
                ena_free_tx_resources(adapter, i);
        return rc;
}

/* ena_free_all_io_tx_resources - Free I/O Tx Resources for All Queues
 * @adapter: board private structure
 *
 * Free all transmit software resources
 */
static void ena_free_all_io_tx_resources(struct ena_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                ena_free_tx_resources(adapter, i);
}

static int validate_rx_req_id(struct ena_ring *rx_ring, u16 req_id)
{
        if (likely(req_id < rx_ring->ring_size))
                return 0;

        netif_err(rx_ring->adapter, rx_err, rx_ring->netdev,
                  "Invalid rx req_id: %hu\n", req_id);

        u64_stats_update_begin(&rx_ring->syncp);
        rx_ring->rx_stats.bad_req_id++;
        u64_stats_update_end(&rx_ring->syncp);

        /* Trigger device reset */
        rx_ring->adapter->reset_reason = ENA_REGS_RESET_INV_RX_REQ_ID;
        set_bit(ENA_FLAG_TRIGGER_RESET, &rx_ring->adapter->flags);
        return -EFAULT;
}

/* ena_setup_rx_resources - allocate I/O Rx resources (Descriptors)
 * @adapter: network interface device structure
 * @qid: queue index
 *
 * Returns 0 on success, negative on failure
 */
static int ena_setup_rx_resources(struct ena_adapter *adapter,
                                  u32 qid)
{
        struct ena_ring *rx_ring = &adapter->rx_ring[qid];
        struct ena_irq *ena_irq = &adapter->irq_tbl[ENA_IO_IRQ_IDX(qid)];
        int size, node, i;

        if (rx_ring->rx_buffer_info) {
                netif_err(adapter, ifup, adapter->netdev,
                          "rx_buffer_info is not NULL");
                return -EEXIST;
        }

        /* alloc extra element so in rx path
         * we can always prefetch rx_info + 1
         */
        size = sizeof(struct ena_rx_buffer) * (rx_ring->ring_size + 1);
        node = cpu_to_node(ena_irq->cpu);

        rx_ring->rx_buffer_info = vzalloc_node(size, node);
        if (!rx_ring->rx_buffer_info) {
                rx_ring->rx_buffer_info = vzalloc(size);
                if (!rx_ring->rx_buffer_info)
                        return -ENOMEM;
        }

        size = sizeof(u16) * rx_ring->ring_size;
        rx_ring->free_ids = vzalloc_node(size, node);
        if (!rx_ring->free_ids) {
                rx_ring->free_ids = vzalloc(size);
                if (!rx_ring->free_ids) {
                        vfree(rx_ring->rx_buffer_info);
                        rx_ring->rx_buffer_info = NULL;
                        return -ENOMEM;
                }
        }

        /* Req id ring for receiving RX pkts out of order */
        for (i = 0; i < rx_ring->ring_size; i++)
                rx_ring->free_ids[i] = i;

        /* Reset rx statistics */
        memset(&rx_ring->rx_stats, 0x0, sizeof(rx_ring->rx_stats));

        rx_ring->next_to_clean = 0;
        rx_ring->next_to_use = 0;
        rx_ring->cpu = ena_irq->cpu;

        return 0;
}

/* ena_free_rx_resources - Free I/O Rx Resources
 * @adapter: network interface device structure
 * @qid: queue index
 *
 * Free all receive software resources
 */
static void ena_free_rx_resources(struct ena_adapter *adapter,
                                  u32 qid)
{
        struct ena_ring *rx_ring = &adapter->rx_ring[qid];

        vfree(rx_ring->rx_buffer_info);
        rx_ring->rx_buffer_info = NULL;

        vfree(rx_ring->free_ids);
        rx_ring->free_ids = NULL;
}

/* ena_setup_all_rx_resources - allocate I/O Rx queues resources for all queues
 * @adapter: board private structure
 *
 * Return 0 on success, negative on failure
 */
static int ena_setup_all_rx_resources(struct ena_adapter *adapter)
{
        int i, rc = 0;

        for (i = 0; i < adapter->num_queues; i++) {
                rc = ena_setup_rx_resources(adapter, i);
                if (rc)
                        goto err_setup_rx;
        }

        return 0;

err_setup_rx:

        netif_err(adapter, ifup, adapter->netdev,
                  "Rx queue %d: allocation failed\n", i);

        /* rewind the index freeing the rings as we go */
        while (i--)
                ena_free_rx_resources(adapter, i);
        return rc;
}

/* ena_free_all_io_rx_resources - Free I/O Rx Resources for All Queues
 * @adapter: board private structure
 *
 * Free all receive software resources
 */
static void ena_free_all_io_rx_resources(struct ena_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                ena_free_rx_resources(adapter, i);
}

static int ena_alloc_rx_page(struct ena_ring *rx_ring,
                                    struct ena_rx_buffer *rx_info, gfp_t gfp)
{
        struct ena_com_buf *ena_buf;
        struct page *page;
        dma_addr_t dma;

        /* if previous allocated page is not used */
        if (unlikely(rx_info->page))
                return 0;

        page = alloc_page(gfp);
        if (unlikely(!page)) {
                u64_stats_update_begin(&rx_ring->syncp);
                rx_ring->rx_stats.page_alloc_fail++;
                u64_stats_update_end(&rx_ring->syncp);
                return -ENOMEM;
        }

        dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE,
                           DMA_FROM_DEVICE);
        if (unlikely(dma_mapping_error(rx_ring->dev, dma))) {
                u64_stats_update_begin(&rx_ring->syncp);
                rx_ring->rx_stats.dma_mapping_err++;
                u64_stats_update_end(&rx_ring->syncp);

                __free_page(page);
                return -EIO;
        }
        netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
                  "alloc page %p, rx_info %p\n", page, rx_info);

        rx_info->page = page;
        rx_info->page_offset = 0;
        ena_buf = &rx_info->ena_buf;
        ena_buf->paddr = dma;
        ena_buf->len = ENA_PAGE_SIZE;

        return 0;
}

static void ena_free_rx_page(struct ena_ring *rx_ring,
                             struct ena_rx_buffer *rx_info)
{
        struct page *page = rx_info->page;
        struct ena_com_buf *ena_buf = &rx_info->ena_buf;

        if (unlikely(!page)) {
                netif_warn(rx_ring->adapter, rx_err, rx_ring->netdev,
                           "Trying to free unallocated buffer\n");
                return;
        }

        dma_unmap_page(rx_ring->dev, ena_buf->paddr, ENA_PAGE_SIZE,
                       DMA_FROM_DEVICE);

        __free_page(page);
        rx_info->page = NULL;
}

static int ena_refill_rx_bufs(struct ena_ring *rx_ring, u32 num)
{
        u16 next_to_use, req_id;
        u32 i;
        int rc;

        next_to_use = rx_ring->next_to_use;

        for (i = 0; i < num; i++) {
                struct ena_rx_buffer *rx_info;

                req_id = rx_ring->free_ids[next_to_use];
                rc = validate_rx_req_id(rx_ring, req_id);
                if (unlikely(rc < 0))
                        break;

                rx_info = &rx_ring->rx_buffer_info[req_id];


                rc = ena_alloc_rx_page(rx_ring, rx_info,
                                       GFP_ATOMIC | __GFP_COMP);
                if (unlikely(rc < 0)) {
                        netif_warn(rx_ring->adapter, rx_err, rx_ring->netdev,
                                   "failed to alloc buffer for rx queue %d\n",
                                   rx_ring->qid);
                        break;
                }
                rc = ena_com_add_single_rx_desc(rx_ring->ena_com_io_sq,
                                                &rx_info->ena_buf,
                                                req_id);
                if (unlikely(rc)) {
                        netif_warn(rx_ring->adapter, rx_status, rx_ring->netdev,
                                   "failed to add buffer for rx queue %d\n",
                                   rx_ring->qid);
                        break;
                }
                next_to_use = ENA_RX_RING_IDX_NEXT(next_to_use,
                                                   rx_ring->ring_size);
        }

        if (unlikely(i < num)) {
                u64_stats_update_begin(&rx_ring->syncp);
                rx_ring->rx_stats.refil_partial++;
                u64_stats_update_end(&rx_ring->syncp);
                netdev_warn(rx_ring->netdev,
                            "refilled rx qid %d with only %d buffers (from %d)\n",
                            rx_ring->qid, i, num);
        }

        /* ena_com_write_sq_doorbell issues a wmb() */
        if (likely(i))
                ena_com_write_sq_doorbell(rx_ring->ena_com_io_sq);

        rx_ring->next_to_use = next_to_use;

        return i;
}

static void ena_free_rx_bufs(struct ena_adapter *adapter,
                             u32 qid)
{
        struct ena_ring *rx_ring = &adapter->rx_ring[qid];
        u32 i;

        for (i = 0; i < rx_ring->ring_size; i++) {
                struct ena_rx_buffer *rx_info = &rx_ring->rx_buffer_info[i];

                if (rx_info->page)
                        ena_free_rx_page(rx_ring, rx_info);
        }
}

/* ena_refill_all_rx_bufs - allocate all queues Rx buffers
 * @adapter: board private structure
 */
static void ena_refill_all_rx_bufs(struct ena_adapter *adapter)
{
        struct ena_ring *rx_ring;
        int i, rc, bufs_num;

        for (i = 0; i < adapter->num_queues; i++) {
                rx_ring = &adapter->rx_ring[i];
                bufs_num = rx_ring->ring_size - 1;
                rc = ena_refill_rx_bufs(rx_ring, bufs_num);

                if (unlikely(rc != bufs_num))
                        netif_warn(rx_ring->adapter, rx_status, rx_ring->netdev,
                                   "refilling Queue %d failed. allocated %d buffers from: %d\n",
                                   i, rc, bufs_num);
        }
}

static void ena_free_all_rx_bufs(struct ena_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                ena_free_rx_bufs(adapter, i);
}

static void ena_unmap_tx_skb(struct ena_ring *tx_ring,
                                    struct ena_tx_buffer *tx_info)
{
        struct ena_com_buf *ena_buf;
        u32 cnt;
        int i;

        ena_buf = tx_info->bufs;
        cnt = tx_info->num_of_bufs;

        if (unlikely(!cnt))
                return;

        if (tx_info->map_linear_data) {
                dma_unmap_single(tx_ring->dev,
                                 dma_unmap_addr(ena_buf, paddr),
                                 dma_unmap_len(ena_buf, len),
                                 DMA_TO_DEVICE);
                ena_buf++;
                cnt--;
        }

        /* unmap remaining mapped pages */
        for (i = 0; i < cnt; i++) {
                dma_unmap_page(tx_ring->dev, dma_unmap_addr(ena_buf, paddr),
                               dma_unmap_len(ena_buf, len), DMA_TO_DEVICE);
                ena_buf++;
        }
}

/* ena_free_tx_bufs - Free Tx Buffers per Queue
 * @tx_ring: TX ring for which buffers be freed
 */
static void ena_free_tx_bufs(struct ena_ring *tx_ring)
{
        bool print_once = true;
        u32 i;

        for (i = 0; i < tx_ring->ring_size; i++) {
                struct ena_tx_buffer *tx_info = &tx_ring->tx_buffer_info[i];

                if (!tx_info->skb)
                        continue;

                if (print_once) {
                        netdev_notice(tx_ring->netdev,
                                      "free uncompleted tx skb qid %d idx 0x%x\n",
                                      tx_ring->qid, i);
                        print_once = false;
                } else {
                        netdev_dbg(tx_ring->netdev,
                                   "free uncompleted tx skb qid %d idx 0x%x\n",
                                   tx_ring->qid, i);
                }

                ena_unmap_tx_skb(tx_ring, tx_info);

                dev_kfree_skb_any(tx_info->skb);
        }
        netdev_tx_reset_queue(netdev_get_tx_queue(tx_ring->netdev,
                                                  tx_ring->qid));
}

static void ena_free_all_tx_bufs(struct ena_adapter *adapter)
{
        struct ena_ring *tx_ring;
        int i;

        for (i = 0; i < adapter->num_queues; i++) {
                tx_ring = &adapter->tx_ring[i];
                ena_free_tx_bufs(tx_ring);
        }
}

static void ena_destroy_all_tx_queues(struct ena_adapter *adapter)
{
        u16 ena_qid;
        int i;

        for (i = 0; i < adapter->num_queues; i++) {
                ena_qid = ENA_IO_TXQ_IDX(i);
                ena_com_destroy_io_queue(adapter->ena_dev, ena_qid);
        }
}

static void ena_destroy_all_rx_queues(struct ena_adapter *adapter)
{
        u16 ena_qid;
        int i;

        for (i = 0; i < adapter->num_queues; i++) {
                ena_qid = ENA_IO_RXQ_IDX(i);
                ena_com_destroy_io_queue(adapter->ena_dev, ena_qid);
        }
}

static void ena_destroy_all_io_queues(struct ena_adapter *adapter)
{
        ena_destroy_all_tx_queues(adapter);
        ena_destroy_all_rx_queues(adapter);
}

static int validate_tx_req_id(struct ena_ring *tx_ring, u16 req_id)
{
        struct ena_tx_buffer *tx_info = NULL;

        if (likely(req_id < tx_ring->ring_size)) {
                tx_info = &tx_ring->tx_buffer_info[req_id];
                if (likely(tx_info->skb))
                        return 0;
        }

        if (tx_info)
                netif_err(tx_ring->adapter, tx_done, tx_ring->netdev,
                          "tx_info doesn't have valid skb\n");
        else
                netif_err(tx_ring->adapter, tx_done, tx_ring->netdev,
                          "Invalid req_id: %hu\n", req_id);

        u64_stats_update_begin(&tx_ring->syncp);
        tx_ring->tx_stats.bad_req_id++;
        u64_stats_update_end(&tx_ring->syncp);

        /* Trigger device reset */
        tx_ring->adapter->reset_reason = ENA_REGS_RESET_INV_TX_REQ_ID;
        set_bit(ENA_FLAG_TRIGGER_RESET, &tx_ring->adapter->flags);
        return -EFAULT;
}

static int ena_clean_tx_irq(struct ena_ring *tx_ring, u32 budget)
{
        struct netdev_queue *txq;
        bool above_thresh;
        u32 tx_bytes = 0;
        u32 total_done = 0;
        u16 next_to_clean;
        u16 req_id;
        int tx_pkts = 0;
        int rc;

        next_to_clean = tx_ring->next_to_clean;
        txq = netdev_get_tx_queue(tx_ring->netdev, tx_ring->qid);

        while (tx_pkts < budget) {
                struct ena_tx_buffer *tx_info;
                struct sk_buff *skb;

                rc = ena_com_tx_comp_req_id_get(tx_ring->ena_com_io_cq,
                                                &req_id);
                if (rc)
                        break;

                rc = validate_tx_req_id(tx_ring, req_id);
                if (rc)
                        break;

                tx_info = &tx_ring->tx_buffer_info[req_id];
                skb = tx_info->skb;

                /* prefetch skb_end_pointer() to speedup skb_shinfo(skb) */
                prefetch(&skb->end);

                tx_info->skb = NULL;
                tx_info->last_jiffies = 0;

                ena_unmap_tx_skb(tx_ring, tx_info);

                netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
                          "tx_poll: q %d skb %p completed\n", tx_ring->qid,
                          skb);

                tx_bytes += skb->len;
                dev_kfree_skb(skb);
                tx_pkts++;
                total_done += tx_info->tx_descs;

                tx_ring->free_ids[next_to_clean] = req_id;
                next_to_clean = ENA_TX_RING_IDX_NEXT(next_to_clean,
                                                     tx_ring->ring_size);
        }

        tx_ring->next_to_clean = next_to_clean;
        ena_com_comp_ack(tx_ring->ena_com_io_sq, total_done);
        ena_com_update_dev_comp_head(tx_ring->ena_com_io_cq);

        netdev_tx_completed_queue(txq, tx_pkts, tx_bytes);

        netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
                  "tx_poll: q %d done. total pkts: %d\n",
                  tx_ring->qid, tx_pkts);

        /* need to make the rings circular update visible to
         * ena_start_xmit() before checking for netif_queue_stopped().
         */
        smp_mb();

        above_thresh = ena_com_sq_have_enough_space(tx_ring->ena_com_io_sq,
                                                    ENA_TX_WAKEUP_THRESH);
        if (unlikely(netif_tx_queue_stopped(txq) && above_thresh)) {
                __netif_tx_lock(txq, smp_processor_id());
                above_thresh =
                        ena_com_sq_have_enough_space(tx_ring->ena_com_io_sq,
                                                     ENA_TX_WAKEUP_THRESH);
                if (netif_tx_queue_stopped(txq) && above_thresh) {
                        netif_tx_wake_queue(txq);
                        u64_stats_update_begin(&tx_ring->syncp);
                        tx_ring->tx_stats.queue_wakeup++;
                        u64_stats_update_end(&tx_ring->syncp);
                }
                __netif_tx_unlock(txq);
        }

        tx_ring->per_napi_bytes += tx_bytes;
        tx_ring->per_napi_packets += tx_pkts;

        return tx_pkts;
}

static struct sk_buff *ena_alloc_skb(struct ena_ring *rx_ring, bool frags)
{
        struct sk_buff *skb;

        if (frags)
                skb = napi_get_frags(rx_ring->napi);
        else
                skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
                                                rx_ring->rx_copybreak);

        if (unlikely(!skb)) {
                u64_stats_update_begin(&rx_ring->syncp);
                rx_ring->rx_stats.skb_alloc_fail++;
                u64_stats_update_end(&rx_ring->syncp);
                netif_dbg(rx_ring->adapter, rx_err, rx_ring->netdev,
                          "Failed to allocate skb. frags: %d\n", frags);
                return NULL;
        }

        return skb;
}

static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
                                  struct ena_com_rx_buf_info *ena_bufs,
                                  u32 descs,
                                  u16 *next_to_clean)
{
        struct sk_buff *skb;
        struct ena_rx_buffer *rx_info;
        u16 len, req_id, buf = 0;
        void *va;

        len = ena_bufs[buf].len;
        req_id = ena_bufs[buf].req_id;
        rx_info = &rx_ring->rx_buffer_info[req_id];

        if (unlikely(!rx_info->page)) {
                netif_err(rx_ring->adapter, rx_err, rx_ring->netdev,
                          "Page is NULL\n");
                return NULL;
        }

        netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
                  "rx_info %p page %p\n",
                  rx_info, rx_info->page);

        /* save virt address of first buffer */
        va = page_address(rx_info->page) + rx_info->page_offset;
        prefetch(va + NET_IP_ALIGN);

        if (len <= rx_ring->rx_copybreak) {
                skb = ena_alloc_skb(rx_ring, false);
                if (unlikely(!skb))
                        return NULL;

                netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
                          "rx allocated small packet. len %d. data_len %d\n",
                          skb->len, skb->data_len);

                /* sync this buffer for CPU use */
                dma_sync_single_for_cpu(rx_ring->dev,
                                        dma_unmap_addr(&rx_info->ena_buf, paddr),
                                        len,
                                        DMA_FROM_DEVICE);
                skb_copy_to_linear_data(skb, va, len);
                dma_sync_single_for_device(rx_ring->dev,
                                           dma_unmap_addr(&rx_info->ena_buf, paddr),
                                           len,
                                           DMA_FROM_DEVICE);

                skb_put(skb, len);
                skb->protocol = eth_type_trans(skb, rx_ring->netdev);
                rx_ring->free_ids[*next_to_clean] = req_id;
                *next_to_clean = ENA_RX_RING_IDX_ADD(*next_to_clean, descs,
                                                     rx_ring->ring_size);
                return skb;
        }

        skb = ena_alloc_skb(rx_ring, true);
        if (unlikely(!skb))
                return NULL;

        do {
                dma_unmap_page(rx_ring->dev,
                               dma_unmap_addr(&rx_info->ena_buf, paddr),
                               ENA_PAGE_SIZE, DMA_FROM_DEVICE);

                skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page,
                                rx_info->page_offset, len, ENA_PAGE_SIZE);

                netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
                          "rx skb updated. len %d. data_len %d\n",
                          skb->len, skb->data_len);

                rx_info->page = NULL;

                rx_ring->free_ids[*next_to_clean] = req_id;
                *next_to_clean =
                        ENA_RX_RING_IDX_NEXT(*next_to_clean,
                                             rx_ring->ring_size);
                if (likely(--descs == 0))
                        break;

                buf++;
                len = ena_bufs[buf].len;
                req_id = ena_bufs[buf].req_id;
                rx_info = &rx_ring->rx_buffer_info[req_id];
        } while (1);

        return skb;
}

/* ena_rx_checksum - indicate in skb if hw indicated a good cksum
 * @adapter: structure containing adapter specific data
 * @ena_rx_ctx: received packet context/metadata
 * @skb: skb currently being received and modified
 */
static void ena_rx_checksum(struct ena_ring *rx_ring,
                                   struct ena_com_rx_ctx *ena_rx_ctx,
                                   struct sk_buff *skb)
{
        /* Rx csum disabled */
        if (unlikely(!(rx_ring->netdev->features & NETIF_F_RXCSUM))) {
                skb->ip_summed = CHECKSUM_NONE;
                return;
        }

        /* For fragmented packets the checksum isn't valid */
        if (ena_rx_ctx->frag) {
                skb->ip_summed = CHECKSUM_NONE;
                return;
        }

        /* if IP and error */
        if (unlikely((ena_rx_ctx->l3_proto == ENA_ETH_IO_L3_PROTO_IPV4) &&
                     (ena_rx_ctx->l3_csum_err))) {
                /* ipv4 checksum error */
                skb->ip_summed = CHECKSUM_NONE;
                u64_stats_update_begin(&rx_ring->syncp);
                rx_ring->rx_stats.bad_csum++;
                u64_stats_update_end(&rx_ring->syncp);
                netif_dbg(rx_ring->adapter, rx_err, rx_ring->netdev,
                          "RX IPv4 header checksum error\n");
                return;
        }

        /* if TCP/UDP */
        if (likely((ena_rx_ctx->l4_proto == ENA_ETH_IO_L4_PROTO_TCP) ||
                   (ena_rx_ctx->l4_proto == ENA_ETH_IO_L4_PROTO_UDP))) {
                if (unlikely(ena_rx_ctx->l4_csum_err)) {
                        /* TCP/UDP checksum error */
                        u64_stats_update_begin(&rx_ring->syncp);
                        rx_ring->rx_stats.bad_csum++;
                        u64_stats_update_end(&rx_ring->syncp);
                        netif_dbg(rx_ring->adapter, rx_err, rx_ring->netdev,
                                  "RX L4 checksum error\n");
                        skb->ip_summed = CHECKSUM_NONE;
                        return;
                }

                if (likely(ena_rx_ctx->l4_csum_checked)) {
                        skb->ip_summed = CHECKSUM_UNNECESSARY;
                        u64_stats_update_begin(&rx_ring->syncp);
                        rx_ring->rx_stats.csum_good++;
                        u64_stats_update_end(&rx_ring->syncp);
                } else {
                        u64_stats_update_begin(&rx_ring->syncp);
                        rx_ring->rx_stats.csum_unchecked++;
                        u64_stats_update_end(&rx_ring->syncp);
                        skb->ip_summed = CHECKSUM_NONE;
                }
        } else {
                skb->ip_summed = CHECKSUM_NONE;
                return;
        }

}

static void ena_set_rx_hash(struct ena_ring *rx_ring,
                            struct ena_com_rx_ctx *ena_rx_ctx,
                            struct sk_buff *skb)
{
        enum pkt_hash_types hash_type;

        if (likely(rx_ring->netdev->features & NETIF_F_RXHASH)) {
                if (likely((ena_rx_ctx->l4_proto == ENA_ETH_IO_L4_PROTO_TCP) ||
                           (ena_rx_ctx->l4_proto == ENA_ETH_IO_L4_PROTO_UDP)))

                        hash_type = PKT_HASH_TYPE_L4;
                else
                        hash_type = PKT_HASH_TYPE_NONE;

                /* Override hash type if the packet is fragmented */
                if (ena_rx_ctx->frag)
                        hash_type = PKT_HASH_TYPE_NONE;

                skb_set_hash(skb, ena_rx_ctx->hash, hash_type);
        }
}

/* ena_clean_rx_irq - Cleanup RX irq
 * @rx_ring: RX ring to clean
 * @napi: napi handler
 * @budget: how many packets driver is allowed to clean
 *
 * Returns the number of cleaned buffers.
 */
static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi,
                            u32 budget)
{
        u16 next_to_clean = rx_ring->next_to_clean;
        u32 res_budget, work_done;

        struct ena_com_rx_ctx ena_rx_ctx;
        struct ena_adapter *adapter;
        struct sk_buff *skb;
        int refill_required;
        int refill_threshold;
        int rc = 0;
        int total_len = 0;
        int rx_copybreak_pkt = 0;
        int i;

        netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
                  "%s qid %d\n", __func__, rx_ring->qid);
        res_budget = budget;

        do {
                ena_rx_ctx.ena_bufs = rx_ring->ena_bufs;
                ena_rx_ctx.max_bufs = rx_ring->sgl_size;
                ena_rx_ctx.descs = 0;
                rc = ena_com_rx_pkt(rx_ring->ena_com_io_cq,
                                    rx_ring->ena_com_io_sq,
                                    &ena_rx_ctx);
                if (unlikely(rc))
                        goto error;

                if (unlikely(ena_rx_ctx.descs == 0))
                        break;

                netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
                          "rx_poll: q %d got packet from ena. descs #: %d l3 proto %d l4 proto %d hash: %x\n",
                          rx_ring->qid, ena_rx_ctx.descs, ena_rx_ctx.l3_proto,
                          ena_rx_ctx.l4_proto, ena_rx_ctx.hash);

                /* allocate skb and fill it */
                skb = ena_rx_skb(rx_ring, rx_ring->ena_bufs, ena_rx_ctx.descs,
                                 &next_to_clean);

                /* exit if we failed to retrieve a buffer */
                if (unlikely(!skb)) {
                        for (i = 0; i < ena_rx_ctx.descs; i++) {
                                rx_ring->free_ids[next_to_clean] =
                                        rx_ring->ena_bufs[i].req_id;
                                next_to_clean =
                                        ENA_RX_RING_IDX_NEXT(next_to_clean,
                                                             rx_ring->ring_size);
                        }
                        break;
                }

                ena_rx_checksum(rx_ring, &ena_rx_ctx, skb);

                ena_set_rx_hash(rx_ring, &ena_rx_ctx, skb);

                skb_record_rx_queue(skb, rx_ring->qid);

                if (rx_ring->ena_bufs[0].len <= rx_ring->rx_copybreak) {
                        total_len += rx_ring->ena_bufs[0].len;
                        rx_copybreak_pkt++;
                        napi_gro_receive(napi, skb);
                } else {
                        total_len += skb->len;
                        napi_gro_frags(napi);
                }

                res_budget--;
        } while (likely(res_budget));

        work_done = budget - res_budget;
        rx_ring->per_napi_bytes += total_len;
        rx_ring->per_napi_packets += work_done;
        u64_stats_update_begin(&rx_ring->syncp);
        rx_ring->rx_stats.bytes += total_len;
        rx_ring->rx_stats.cnt += work_done;
        rx_ring->rx_stats.rx_copybreak_pkt += rx_copybreak_pkt;
        u64_stats_update_end(&rx_ring->syncp);

        rx_ring->next_to_clean = next_to_clean;

        refill_required = ena_com_free_desc(rx_ring->ena_com_io_sq);
        refill_threshold =
                min_t(int, rx_ring->ring_size / ENA_RX_REFILL_THRESH_DIVIDER,
                      ENA_RX_REFILL_THRESH_PACKET);

        /* Optimization, try to batch new rx buffers */
        if (refill_required > refill_threshold) {
                ena_com_update_dev_comp_head(rx_ring->ena_com_io_cq);
                ena_refill_rx_bufs(rx_ring, refill_required);
        }

        return work_done;

error:
        adapter = netdev_priv(rx_ring->netdev);

        u64_stats_update_begin(&rx_ring->syncp);
        rx_ring->rx_stats.bad_desc_num++;
        u64_stats_update_end(&rx_ring->syncp);

        /* Too many desc from the device. Trigger reset */
        adapter->reset_reason = ENA_REGS_RESET_TOO_MANY_RX_DESCS;
        set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);

        return 0;
}

void ena_adjust_intr_moderation(struct ena_ring *rx_ring,
                                       struct ena_ring *tx_ring)
{
        /* We apply adaptive moderation on Rx path only.
         * Tx uses static interrupt moderation.
         */
        ena_com_calculate_interrupt_delay(rx_ring->ena_dev,
                                          rx_ring->per_napi_packets,
                                          rx_ring->per_napi_bytes,
                                          &rx_ring->smoothed_interval,
                                          &rx_ring->moder_tbl_idx);

        /* Reset per napi packets/bytes */
        tx_ring->per_napi_packets = 0;
        tx_ring->per_napi_bytes = 0;
        rx_ring->per_napi_packets = 0;
        rx_ring->per_napi_bytes = 0;
}

static void ena_unmask_interrupt(struct ena_ring *tx_ring,
                                        struct ena_ring *rx_ring)
{
        struct ena_eth_io_intr_reg intr_reg;

        /* Update intr register: rx intr delay,
         * tx intr delay and interrupt unmask
         */
        ena_com_update_intr_reg(&intr_reg,
                                rx_ring->smoothed_interval,
                                tx_ring->smoothed_interval,
                                true);

        /* It is a shared MSI-X.
         * Tx and Rx CQ have pointer to it.
         * So we use one of them to reach the intr reg
         */
        ena_com_unmask_intr(rx_ring->ena_com_io_cq, &intr_reg);
}

static void ena_update_ring_numa_node(struct ena_ring *tx_ring,
                                             struct ena_ring *rx_ring)
{
        int cpu = get_cpu();
        int numa_node;

        /* Check only one ring since the 2 rings are running on the same cpu */
        if (likely(tx_ring->cpu == cpu))
                goto out;

        numa_node = cpu_to_node(cpu);
        put_cpu();

        if (numa_node != NUMA_NO_NODE) {
                ena_com_update_numa_node(tx_ring->ena_com_io_cq, numa_node);
                ena_com_update_numa_node(rx_ring->ena_com_io_cq, numa_node);
        }

        tx_ring->cpu = cpu;
        rx_ring->cpu = cpu;

        return;
out:
        put_cpu();
}

static int ena_io_poll(struct napi_struct *napi, int budget)
{
        struct ena_napi *ena_napi = container_of(napi, struct ena_napi, napi);
        struct ena_ring *tx_ring, *rx_ring;

        u32 tx_work_done;
        u32 rx_work_done;
        int tx_budget;
        int napi_comp_call = 0;
        int ret;

        tx_ring = ena_napi->tx_ring;
        rx_ring = ena_napi->rx_ring;

        tx_budget = tx_ring->ring_size / ENA_TX_POLL_BUDGET_DIVIDER;

        if (!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags) ||
            test_bit(ENA_FLAG_TRIGGER_RESET, &tx_ring->adapter->flags)) {
                napi_complete_done(napi, 0);
                return 0;
        }

        tx_work_done = ena_clean_tx_irq(tx_ring, tx_budget);
        rx_work_done = ena_clean_rx_irq(rx_ring, napi, budget);

        /* If the device is about to reset or down, avoid unmask
         * the interrupt and return 0 so NAPI won't reschedule
         */
        if (unlikely(!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags) ||
                     test_bit(ENA_FLAG_TRIGGER_RESET, &tx_ring->adapter->flags))) {
                napi_complete_done(napi, 0);
                ret = 0;

        } else if ((budget > rx_work_done) && (tx_budget > tx_work_done)) {
                napi_comp_call = 1;

                /* Update numa and unmask the interrupt only when schedule
                 * from the interrupt context (vs from sk_busy_loop)
                 */
                if (napi_complete_done(napi, rx_work_done)) {
                        /* Tx and Rx share the same interrupt vector */
                        if (ena_com_get_adaptive_moderation_enabled(rx_ring->ena_dev))
                                ena_adjust_intr_moderation(rx_ring, tx_ring);

                        ena_unmask_interrupt(tx_ring, rx_ring);
                }

                ena_update_ring_numa_node(tx_ring, rx_ring);

                ret = rx_work_done;
        } else {
                ret = budget;
        }

        u64_stats_update_begin(&tx_ring->syncp);
        tx_ring->tx_stats.napi_comp += napi_comp_call;
        tx_ring->tx_stats.tx_poll++;
        u64_stats_update_end(&tx_ring->syncp);

        return ret;
}

static irqreturn_t ena_intr_msix_mgmnt(int irq, void *data)
{
        struct ena_adapter *adapter = (struct ena_adapter *)data;

        ena_com_admin_q_comp_intr_handler(adapter->ena_dev);

        /* Don't call the aenq handler before probe is done */
        if (likely(test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags)))
                ena_com_aenq_intr_handler(adapter->ena_dev, data);

        return IRQ_HANDLED;
}

/* ena_intr_msix_io - MSI-X Interrupt Handler for Tx/Rx
 * @irq: interrupt number
 * @data: pointer to a network interface private napi device structure
 */
static irqreturn_t ena_intr_msix_io(int irq, void *data)
{
        struct ena_napi *ena_napi = data;

        ena_napi->tx_ring->first_interrupt = true;
        ena_napi->rx_ring->first_interrupt = true;

        napi_schedule_irqoff(&ena_napi->napi);

        return IRQ_HANDLED;
}

/* Reserve a single MSI-X vector for management (admin + aenq).
 * plus reserve one vector for each potential io queue.
 * the number of potential io queues is the minimum of what the device
 * supports and the number of vCPUs.
 */
static int ena_enable_msix(struct ena_adapter *adapter, int num_queues)
{
        int msix_vecs, irq_cnt;

        if (test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
                netif_err(adapter, probe, adapter->netdev,
                          "Error, MSI-X is already enabled\n");
                return -EPERM;
        }

        /* Reserved the max msix vectors we might need */
        msix_vecs = ENA_MAX_MSIX_VEC(num_queues);
        netif_dbg(adapter, probe, adapter->netdev,
                  "trying to enable MSI-X, vectors %d\n", msix_vecs);

        irq_cnt = pci_alloc_irq_vectors(adapter->pdev, ENA_MIN_MSIX_VEC,
                                        msix_vecs, PCI_IRQ_MSIX);

        if (irq_cnt < 0) {
                netif_err(adapter, probe, adapter->netdev,
                          "Failed to enable MSI-X. irq_cnt %d\n", irq_cnt);
                return -ENOSPC;
        }

        if (irq_cnt != msix_vecs) {
                netif_notice(adapter, probe, adapter->netdev,
                             "enable only %d MSI-X (out of %d), reduce the number of queues\n",
                             irq_cnt, msix_vecs);
                adapter->num_queues = irq_cnt - ENA_ADMIN_MSIX_VEC;
        }

        if (ena_init_rx_cpu_rmap(adapter))
                netif_warn(adapter, probe, adapter->netdev,
                           "Failed to map IRQs to CPUs\n");

        adapter->msix_vecs = irq_cnt;
        set_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags);

        return 0;
}

static void ena_setup_mgmnt_intr(struct ena_adapter *adapter)
{
        u32 cpu;

        snprintf(adapter->irq_tbl[ENA_MGMNT_IRQ_IDX].name,
                 ENA_IRQNAME_SIZE, "ena-mgmnt@pci:%s",
                 pci_name(adapter->pdev));
        adapter->irq_tbl[ENA_MGMNT_IRQ_IDX].handler =
                ena_intr_msix_mgmnt;
        adapter->irq_tbl[ENA_MGMNT_IRQ_IDX].data = adapter;
        adapter->irq_tbl[ENA_MGMNT_IRQ_IDX].vector =
                pci_irq_vector(adapter->pdev, ENA_MGMNT_IRQ_IDX);
        cpu = cpumask_first(cpu_online_mask);
        adapter->irq_tbl[ENA_MGMNT_IRQ_IDX].cpu = cpu;
        cpumask_set_cpu(cpu,
                        &adapter->irq_tbl[ENA_MGMNT_IRQ_IDX].affinity_hint_mask);
}

static void ena_setup_io_intr(struct ena_adapter *adapter)
{
        struct net_device *netdev;
        int irq_idx, i, cpu;

        netdev = adapter->netdev;

        for (i = 0; i < adapter->num_queues; i++) {
                irq_idx = ENA_IO_IRQ_IDX(i);
                cpu = i % num_online_cpus();

                snprintf(adapter->irq_tbl[irq_idx].name, ENA_IRQNAME_SIZE,
                         "%s-Tx-Rx-%d", netdev->name, i);
                adapter->irq_tbl[irq_idx].handler = ena_intr_msix_io;
                adapter->irq_tbl[irq_idx].data = &adapter->ena_napi[i];
                adapter->irq_tbl[irq_idx].vector =
                        pci_irq_vector(adapter->pdev, irq_idx);
                adapter->irq_tbl[irq_idx].cpu = cpu;

                cpumask_set_cpu(cpu,
                                &adapter->irq_tbl[irq_idx].affinity_hint_mask);
        }
}

static int ena_request_mgmnt_irq(struct ena_adapter *adapter)
{
        unsigned long flags = 0;
        struct ena_irq *irq;
        int rc;

        irq = &adapter->irq_tbl[ENA_MGMNT_IRQ_IDX];
        rc = request_irq(irq->vector, irq->handler, flags, irq->name,
                         irq->data);
        if (rc) {
                netif_err(adapter, probe, adapter->netdev,
                          "failed to request admin irq\n");
                return rc;
        }

        netif_dbg(adapter, probe, adapter->netdev,
                  "set affinity hint of mgmnt irq.to 0x%lx (irq vector: %d)\n",
                  irq->affinity_hint_mask.bits[0], irq->vector);

        irq_set_affinity_hint(irq->vector, &irq->affinity_hint_mask);

        return rc;
}

static int ena_request_io_irq(struct ena_adapter *adapter)
{
        unsigned long flags = 0;
        struct ena_irq *irq;
        int rc = 0, i, k;

        if (!test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
                netif_err(adapter, ifup, adapter->netdev,
                          "Failed to request I/O IRQ: MSI-X is not enabled\n");
                return -EINVAL;
        }

        for (i = ENA_IO_IRQ_FIRST_IDX; i < adapter->msix_vecs; i++) {
                irq = &adapter->irq_tbl[i];
                rc = request_irq(irq->vector, irq->handler, flags, irq->name,
                                 irq->data);
                if (rc) {
                        netif_err(adapter, ifup, adapter->netdev,
                                  "Failed to request I/O IRQ. index %d rc %d\n",
                                   i, rc);
                        goto err;
                }

                netif_dbg(adapter, ifup, adapter->netdev,
                          "set affinity hint of irq. index %d to 0x%lx (irq vector: %d)\n",
                          i, irq->affinity_hint_mask.bits[0], irq->vector);

                irq_set_affinity_hint(irq->vector, &irq->affinity_hint_mask);
        }

        return rc;

err:
        for (k = ENA_IO_IRQ_FIRST_IDX; k < i; k++) {
                irq = &adapter->irq_tbl[k];
                free_irq(irq->vector, irq->data);
        }

        return rc;
}

static void ena_free_mgmnt_irq(struct ena_adapter *adapter)
{
        struct ena_irq *irq;

        irq = &adapter->irq_tbl[ENA_MGMNT_IRQ_IDX];
        synchronize_irq(irq->vector);
        irq_set_affinity_hint(irq->vector, NULL);
        free_irq(irq->vector, irq->data);
}

static void ena_free_io_irq(struct ena_adapter *adapter)
{
        struct ena_irq *irq;
        int i;

#ifdef CONFIG_RFS_ACCEL
        if (adapter->msix_vecs >= 1) {
                free_irq_cpu_rmap(adapter->netdev->rx_cpu_rmap);
                adapter->netdev->rx_cpu_rmap = NULL;
        }
#endif /* CONFIG_RFS_ACCEL */

        for (i = ENA_IO_IRQ_FIRST_IDX; i < adapter->msix_vecs; i++) {
                irq = &adapter->irq_tbl[i];
                irq_set_affinity_hint(irq->vector, NULL);
                free_irq(irq->vector, irq->data);
        }
}

static void ena_disable_msix(struct ena_adapter *adapter)
{
        if (test_and_clear_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags))
                pci_free_irq_vectors(adapter->pdev);
}

static void ena_disable_io_intr_sync(struct ena_adapter *adapter)
{
        int i;

        if (!netif_running(adapter->netdev))
                return;

        for (i = ENA_IO_IRQ_FIRST_IDX; i < adapter->msix_vecs; i++)
                synchronize_irq(adapter->irq_tbl[i].vector);
}

static void ena_del_napi(struct ena_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                netif_napi_del(&adapter->ena_napi[i].napi);
}

static void ena_init_napi(struct ena_adapter *adapter)
{
        struct ena_napi *napi;
        int i;

        for (i = 0; i < adapter->num_queues; i++) {
                napi = &adapter->ena_napi[i];

                netif_napi_add(adapter->netdev,
                               &adapter->ena_napi[i].napi,
                               ena_io_poll,
                               ENA_NAPI_BUDGET);
                napi->rx_ring = &adapter->rx_ring[i];
                napi->tx_ring = &adapter->tx_ring[i];
                napi->qid = i;
        }
}

static void ena_napi_disable_all(struct ena_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                napi_disable(&adapter->ena_napi[i].napi);
}

static void ena_napi_enable_all(struct ena_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++)
                napi_enable(&adapter->ena_napi[i].napi);
}

static void ena_restore_ethtool_params(struct ena_adapter *adapter)
{
        adapter->tx_usecs = 0;
        adapter->rx_usecs = 0;
        adapter->tx_frames = 1;
        adapter->rx_frames = 1;
}

/* Configure the Rx forwarding */
static int ena_rss_configure(struct ena_adapter *adapter)
{
        struct ena_com_dev *ena_dev = adapter->ena_dev;
        int rc;

        /* In case the RSS table wasn't initialized by probe */
        if (!ena_dev->rss.tbl_log_size) {
                rc = ena_rss_init_default(adapter);
                if (rc && (rc != -EOPNOTSUPP)) {
                        netif_err(adapter, ifup, adapter->netdev,
                                  "Failed to init RSS rc: %d\n", rc);
                        return rc;
                }
        }

        /* Set indirect table */
        rc = ena_com_indirect_table_set(ena_dev);
        if (unlikely(rc && rc != -EOPNOTSUPP))
                return rc;

        /* Configure hash function (if supported) */
        rc = ena_com_set_hash_function(ena_dev);
        if (unlikely(rc && (rc != -EOPNOTSUPP)))
                return rc;

        /* Configure hash inputs (if supported) */
        rc = ena_com_set_hash_ctrl(ena_dev);
        if (unlikely(rc && (rc != -EOPNOTSUPP)))
                return rc;

        return 0;
}

static int ena_up_complete(struct ena_adapter *adapter)
{
        int rc;

        rc = ena_rss_configure(adapter);
        if (rc)
                return rc;

        ena_change_mtu(adapter->netdev, adapter->netdev->mtu);

        ena_refill_all_rx_bufs(adapter);

        /* enable transmits */
        netif_tx_start_all_queues(adapter->netdev);

        ena_restore_ethtool_params(adapter);

        ena_napi_enable_all(adapter);

        return 0;
}

static int ena_create_io_tx_queue(struct ena_adapter *adapter, int qid)
{
        struct ena_com_create_io_ctx ctx;
        struct ena_com_dev *ena_dev;
        struct ena_ring *tx_ring;
        u32 msix_vector;
        u16 ena_qid;
        int rc;

        ena_dev = adapter->ena_dev;

        tx_ring = &adapter->tx_ring[qid];
        msix_vector = ENA_IO_IRQ_IDX(qid);
        ena_qid = ENA_IO_TXQ_IDX(qid);

        memset(&ctx, 0x0, sizeof(ctx));

        ctx.direction = ENA_COM_IO_QUEUE_DIRECTION_TX;
        ctx.qid = ena_qid;
        ctx.mem_queue_type = ena_dev->tx_mem_queue_type;
        ctx.msix_vector = msix_vector;
        ctx.queue_size = tx_ring->ring_size;
        ctx.numa_node = cpu_to_node(tx_ring->cpu);

        rc = ena_com_create_io_queue(ena_dev, &ctx);
        if (rc) {
                netif_err(adapter, ifup, adapter->netdev,
                          "Failed to create I/O TX queue num %d rc: %d\n",
                          qid, rc);
                return rc;
        }

        rc = ena_com_get_io_handlers(ena_dev, ena_qid,
                                     &tx_ring->ena_com_io_sq,
                                     &tx_ring->ena_com_io_cq);
        if (rc) {
                netif_err(adapter, ifup, adapter->netdev,
                          "Failed to get TX queue handlers. TX queue num %d rc: %d\n",
                          qid, rc);
                ena_com_destroy_io_queue(ena_dev, ena_qid);
                return rc;
        }

        ena_com_update_numa_node(tx_ring->ena_com_io_cq, ctx.numa_node);
        return rc;
}

static int ena_create_all_io_tx_queues(struct ena_adapter *adapter)
{
        struct ena_com_dev *ena_dev = adapter->ena_dev;
        int rc, i;

        for (i = 0; i < adapter->num_queues; i++) {
                rc = ena_create_io_tx_queue(adapter, i);
                if (rc)
                        goto create_err;
        }

        return 0;

create_err:
        while (i--)
                ena_com_destroy_io_queue(ena_dev, ENA_IO_TXQ_IDX(i));

        return rc;
}

static int ena_create_io_rx_queue(struct ena_adapter *adapter, int qid)
{
        struct ena_com_dev *ena_dev;
        struct ena_com_create_io_ctx ctx;
        struct ena_ring *rx_ring;
        u32 msix_vector;
        u16 ena_qid;
        int rc;

        ena_dev = adapter->ena_dev;

        rx_ring = &adapter->rx_ring[qid];
        msix_vector = ENA_IO_IRQ_IDX(qid);
        ena_qid = ENA_IO_RXQ_IDX(qid);

        memset(&ctx, 0x0, sizeof(ctx));

        ctx.qid = ena_qid;
        ctx.direction = ENA_COM_IO_QUEUE_DIRECTION_RX;
        ctx.mem_queue_type = ENA_ADMIN_PLACEMENT_POLICY_HOST;
        ctx.msix_vector = msix_vector;
        ctx.queue_size = rx_ring->ring_size;
        ctx.numa_node = cpu_to_node(rx_ring->cpu);

        rc = ena_com_create_io_queue(ena_dev, &ctx);
        if (rc) {
                netif_err(adapter, ifup, adapter->netdev,
                          "Failed to create I/O RX queue num %d rc: %d\n",
                          qid, rc);
                return rc;
        }

        rc = ena_com_get_io_handlers(ena_dev, ena_qid,
                                     &rx_ring->ena_com_io_sq,
                                     &rx_ring->ena_com_io_cq);
        if (rc) {
                netif_err(adapter, ifup, adapter->netdev,
                          "Failed to get RX queue handlers. RX queue num %d rc: %d\n",
                          qid, rc);
                ena_com_destroy_io_queue(ena_dev, ena_qid);
                return rc;
        }

        ena_com_update_numa_node(rx_ring->ena_com_io_cq, ctx.numa_node);

        return rc;
}

static int ena_create_all_io_rx_queues(struct ena_adapter *adapter)
{
        struct ena_com_dev *ena_dev = adapter->ena_dev;
        int rc, i;

        for (i = 0; i < adapter->num_queues; i++) {
                rc = ena_create_io_rx_queue(adapter, i);
                if (rc)
                        goto create_err;
        }

        return 0;

create_err:
        while (i--)
                ena_com_destroy_io_queue(ena_dev, ENA_IO_RXQ_IDX(i));

        return rc;
}

static void set_io_rings_size(struct ena_adapter *adapter,
                                     int new_tx_size, int new_rx_size)
{
        int i;

        for (i = 0; i < adapter->num_queues; i++) {
                adapter->tx_ring[i].ring_size = new_tx_size;
                adapter->rx_ring[i].ring_size = new_rx_size;
        }
}

/* This function allows queue allocation to backoff when the system is
 * low on memory. If there is not enough memory to allocate io queues
 * the driver will try to allocate smaller queues.
 *
 * The backoff algorithm is as follows:
 *  1. Try to allocate TX and RX and if successful.
 *  1.1. return success
 *
 *  2. Divide by 2 the size of the larger of RX and TX queues (or both if their size is the same).
 *
 *  3. If TX or RX is smaller than 256
 *  3.1. return failure.
 *  4. else
 *  4.1. go back to 1.
 */
static int create_queues_with_size_backoff(struct ena_adapter *adapter)
{
        int rc, cur_rx_ring_size, cur_tx_ring_size;
        int new_rx_ring_size, new_tx_ring_size;

        /* current queue sizes might be set to smaller than the requested
         * ones due to past queue allocation failures.
         */
        set_io_rings_size(adapter, adapter->requested_tx_ring_size,
                          adapter->requested_rx_ring_size);

        while (1) {
                rc = ena_setup_all_tx_resources(adapter);
                if (rc)
                        goto err_setup_tx;

                rc = ena_create_all_io_tx_queues(adapter);
                if (rc)
                        goto err_create_tx_queues;

                rc = ena_setup_all_rx_resources(adapter);
                if (rc)
                        goto err_setup_rx;

                rc = ena_create_all_io_rx_queues(adapter);
                if (rc)
                        goto err_create_rx_queues;

                return 0;

err_create_rx_queues:
                ena_free_all_io_rx_resources(adapter);
err_setup_rx:
                ena_destroy_all_tx_queues(adapter);
err_create_tx_queues:
                ena_free_all_io_tx_resources(adapter);
err_setup_tx:
                if (rc != -ENOMEM) {
                        netif_err(adapter, ifup, adapter->netdev,
                                  "Queue creation failed with error code %d\n",
                                  rc);
                        return rc;
                }

                cur_tx_ring_size = adapter->tx_ring[0].ring_size;
                cur_rx_ring_size = adapter->rx_ring[0].ring_size;

                netif_err(adapter, ifup, adapter->netdev,
                          "Not enough memory to create queues with sizes TX=%d, RX=%d\n",
                          cur_tx_ring_size, cur_rx_ring_size);

                new_tx_ring_size = cur_tx_ring_size;
                new_rx_ring_size = cur_rx_ring_size;

                /* Decrease the size of the larger queue, or
                 * decrease both if they are the same size.
                 */
                if (cur_rx_ring_size <= cur_tx_ring_size)
                        new_tx_ring_size = cur_tx_ring_size / 2;
                if (cur_rx_ring_size >= cur_tx_ring_size)
                        new_rx_ring_size = cur_rx_ring_size / 2;

                if (new_tx_ring_size < ENA_MIN_RING_SIZE ||
                    new_rx_ring_size < ENA_MIN_RING_SIZE) {
                        netif_err(adapter, ifup, adapter->netdev,
                                  "Queue creation failed with the smallest possible queue size of %d for both queues. Not retrying with smaller queues\n",
                                  ENA_MIN_RING_SIZE);
                        return rc;
                }

                netif_err(adapter, ifup, adapter->netdev,
                          "Retrying queue creation with sizes TX=%d, RX=%d\n",
                          new_tx_ring_size,
                          new_rx_ring_size);

                set_io_rings_size(adapter, new_tx_ring_size,
                                  new_rx_ring_size);
        }
}

static int ena_up(struct ena_adapter *adapter)
{
        int rc, i;

        netdev_dbg(adapter->netdev, "%s\n", __func__);

        ena_setup_io_intr(adapter);

        /* napi poll functions should be initialized before running
         * request_irq(), to handle a rare condition where there is a pending
         * interrupt, causing the ISR to fire immediately while the poll
         * function wasn't set yet, causing a null dereference
         */
        ena_init_napi(adapter);

        rc = ena_request_io_irq(adapter);
        if (rc)
                goto err_req_irq;

        rc = create_queues_with_size_backoff(adapter);
        if (rc)
                goto err_create_queues_with_backoff;

        rc = ena_up_complete(adapter);
        if (rc)
                goto err_up;

        if (test_bit(ENA_FLAG_LINK_UP, &adapter->flags))
                netif_carrier_on(adapter->netdev);

        u64_stats_update_begin(&adapter->syncp);
        adapter->dev_stats.interface_up++;
        u64_stats_update_end(&adapter->syncp);

        set_bit(ENA_FLAG_DEV_UP, &adapter->flags);

        /* Enable completion queues interrupt */
        for (i = 0; i < adapter->num_queues; i++)
                ena_unmask_interrupt(&adapter->tx_ring[i],
                                     &adapter->rx_ring[i]);

        /* schedule napi in case we had pending packets
         * from the last time we disable napi
         */
        for (i = 0; i < adapter->num_queues; i++)
                napi_schedule(&adapter->ena_napi[i].napi);

        return rc;

err_up:
        ena_destroy_all_tx_queues(adapter);
        ena_free_all_io_tx_resources(adapter);
        ena_destroy_all_rx_queues(adapter);
        ena_free_all_io_rx_resources(adapter);
err_create_queues_with_backoff:
        ena_free_io_irq(adapter);
err_req_irq:
        ena_del_napi(adapter);

        return rc;
}

static void ena_down(struct ena_adapter *adapter)
{
        netif_info(adapter, ifdown, adapter->netdev, "%s\n", __func__);

        clear_bit(ENA_FLAG_DEV_UP, &adapter->flags);

        u64_stats_update_begin(&adapter->syncp);
        adapter->dev_stats.interface_down++;
        u64_stats_update_end(&adapter->syncp);

        netif_carrier_off(adapter->netdev);
        netif_tx_disable(adapter->netdev);

        /* After this point the napi handler won't enable the tx queue */
        ena_napi_disable_all(adapter);

        /* After destroy the queue there won't be any new interrupts */

        if (test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags)) {
                int rc;

                rc = ena_com_dev_reset(adapter->ena_dev, adapter->reset_reason);
                if (rc)
                        dev_err(&adapter->pdev->dev, "Device reset failed\n");
                /* stop submitting admin commands on a device that was reset */
                ena_com_set_admin_running_state(adapter->ena_dev, false);
        }

        ena_destroy_all_io_queues(adapter);

        ena_disable_io_intr_sync(adapter);
        ena_free_io_irq(adapter);
        ena_del_napi(adapter);

        ena_free_all_tx_bufs(adapter);
        ena_free_all_rx_bufs(adapter);
        ena_free_all_io_tx_resources(adapter);
        ena_free_all_io_rx_resources(adapter);
}

/* ena_open - Called when a network interface is made active
 * @netdev: network interface device structure
 *
 * Returns 0 on success, negative value on failure
 *
 * The open entry point is called when a network interface is made
 * active by the system (IFF_UP).  At this point all resources needed
 * for transmit and receive operations are allocated, the interrupt
 * handler is registered with the OS, the watchdog timer is started,
 * and the stack is notified that the interface is ready.
 */
static int ena_open(struct net_device *netdev)
{
        struct ena_adapter *adapter = netdev_priv(netdev);
        int rc;

        /* Notify the stack of the actual queue counts. */
        rc = netif_set_real_num_tx_queues(netdev, adapter->num_queues);
        if (rc) {
                netif_err(adapter, ifup, netdev, "Can't set num tx queues\n");
                return rc;
        }

        rc = netif_set_real_num_rx_queues(netdev, adapter->num_queues);
        if (rc) {
                netif_err(adapter, ifup, netdev, "Can't set num rx queues\n");
                return rc;
        }

        rc = ena_up(adapter);
        if (rc)
                return rc;

        return rc;
}

/* ena_close - Disables a network interface
 * @netdev: network interface device structure
 *

 * Returns 0, this is not allowed to fail
 *
 * The close entry point is called when an interface is de-activated
 * by the OS.  The hardware is still under the drivers control, but
 * needs to be disabled.  A global MAC reset is issued to stop the
 * hardware, and all transmit and receive resources are freed.
 */
static int ena_close(struct net_device *netdev)
{
        struct ena_adapter *adapter = netdev_priv(netdev);

        netif_dbg(adapter, ifdown, netdev, "%s\n", __func__);

        if (!test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
                return 0;

        if (test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
                ena_down(adapter);

        /* Check for device status and issue reset if needed*/
        check_for_admin_com_state(adapter);
        if (unlikely(test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags))) {
                netif_err(adapter, ifdown, adapter->netdev,
                          "Destroy failure, restarting device\n");
                ena_dump_stats_to_dmesg(adapter);
                /* rtnl lock already obtained in dev_ioctl() layer */
                ena_destroy_device(adapter, false);
                ena_restore_device(adapter);
        }

        return 0;
}

int ena_update_queue_sizes(struct ena_adapter *adapter,
                           u32 new_tx_size,
                           u32 new_rx_size)
{
        bool dev_up;

        dev_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
        ena_close(adapter->netdev);
        adapter->requested_tx_ring_size = new_tx_size;
        adapter->requested_rx_ring_size = new_rx_size;
        ena_init_io_rings(adapter);
        return dev_up ? ena_up(adapter) : 0;
}

static void ena_tx_csum(struct ena_com_tx_ctx *ena_tx_ctx, struct sk_buff *skb)
{
        u32 mss = skb_shinfo(skb)->gso_size;
        struct ena_com_tx_meta *ena_meta = &ena_tx_ctx->ena_meta;
        u8 l4_protocol = 0;

        if ((skb->ip_summed == CHECKSUM_PARTIAL) || mss) {
                ena_tx_ctx->l4_csum_enable = 1;
                if (mss) {
                        ena_tx_ctx->tso_enable = 1;
                        ena_meta->l4_hdr_len = tcp_hdr(skb)->doff;
                        ena_tx_ctx->l4_csum_partial = 0;
                } else {
                        ena_tx_ctx->tso_enable = 0;
                        ena_meta->l4_hdr_len = 0;
                        ena_tx_ctx->l4_csum_partial = 1;
                }

                switch (ip_hdr(skb)->version) {
                case IPVERSION:
                        ena_tx_ctx->l3_proto = ENA_ETH_IO_L3_PROTO_IPV4;
                        if (ip_hdr(skb)->frag_off & htons(IP_DF))
                                ena_tx_ctx->df = 1;
                        if (mss)
                                ena_tx_ctx->l3_csum_enable = 1;
                        l4_protocol = ip_hdr(skb)->protocol;
                        break;
                case 6:
                        ena_tx_ctx->l3_proto = ENA_ETH_IO_L3_PROTO_IPV6;
                        l4_protocol = ipv6_hdr(skb)->nexthdr;
                        break;
                default:
                        break;
                }

                if (l4_protocol == IPPROTO_TCP)
                        ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_TCP;
                else
                        ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_UDP;

                ena_meta->mss = mss;
                ena_meta->l3_hdr_len = skb_network_header_len(skb);
                ena_meta->l3_hdr_offset = skb_network_offset(skb);
                ena_tx_ctx->meta_valid = 1;

        } else {
                ena_tx_ctx->meta_valid = 0;
        }
}

static int ena_check_and_linearize_skb(struct ena_ring *tx_ring,
                                       struct sk_buff *skb)
{
        int num_frags, header_len, rc;

        num_frags = skb_shinfo(skb)->nr_frags;
        header_len = skb_headlen(skb);

        if (num_frags < tx_ring->sgl_size)
                return 0;

        if ((num_frags == tx_ring->sgl_size) &&
            (header_len < tx_ring->tx_max_header_size))
                return 0;

        u64_stats_update_begin(&tx_ring->syncp);
        tx_ring->tx_stats.linearize++;
        u64_stats_update_end(&tx_ring->syncp);

        rc = skb_linearize(skb);
        if (unlikely(rc)) {
                u64_stats_update_begin(&tx_ring->syncp);
                tx_ring->tx_stats.linearize_failed++;
                u64_stats_update_end(&tx_ring->syncp);
        }

        return rc;
}

static int ena_tx_map_skb(struct ena_ring *tx_ring,
                          struct ena_tx_buffer *tx_info,
                          struct sk_buff *skb,
                          void **push_hdr,
                          u16 *header_len)
{
        struct ena_adapter *adapter = tx_ring->adapter;
        struct ena_com_buf *ena_buf;
        dma_addr_t dma;
        u32 skb_head_len, frag_len, last_frag;
        u16 push_len = 0;
        u16 delta = 0;
        int i = 0;

        skb_head_len = skb_headlen(skb);
        tx_info->skb = skb;
        ena_buf = tx_info->bufs;

        if (tx_ring->tx_mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) {
                /* When the device is LLQ mode, the driver will copy
                 * the header into the device memory space.
                 * the ena_com layer assume the header is in a linear
                 * memory space.
                 * This assumption might be wrong since part of the header
                 * can be in the fragmented buffers.
                 * Use skb_header_pointer to make sure the header is in a
                 * linear memory space.
                 */

                push_len = min_t(u32, skb->len, tx_ring->tx_max_header_size);
                *push_hdr = skb_header_pointer(skb, 0, push_len,
                                               tx_ring->push_buf_intermediate_buf);
                *header_len = push_len;
                if (unlikely(skb->data != *push_hdr)) {
                        u64_stats_update_begin(&tx_ring->syncp);
                        tx_ring->tx_stats.llq_buffer_copy++;
                        u64_stats_update_end(&tx_ring->syncp);

                        delta = push_len - skb_head_len;
                }
        } else {
                *push_hdr = NULL;
                *header_len = min_t(u32, skb_head_len,
                                    tx_ring->tx_max_header_size);
        }

        netif_dbg(adapter, tx_queued, adapter->netdev,
                  "skb: %p header_buf->vaddr: %p push_len: %d\n", skb,
                  *push_hdr, push_len);

        if (skb_head_len > push_len) {
                dma = dma_map_single(tx_ring->dev, skb->data + push_len,
                                     skb_head_len - push_len, DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(tx_ring->dev, dma)))
                        goto error_report_dma_error;

                ena_buf->paddr = dma;
                ena_buf->len = skb_head_len - push_len;

                ena_buf++;
                tx_info->num_of_bufs++;
                tx_info->map_linear_data = 1;
        } else {
                tx_info->map_linear_data = 0;
        }

        last_frag = skb_shinfo(skb)->nr_frags;

        for (i = 0; i < last_frag; i++) {
                const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

                frag_len = skb_frag_size(frag);

                if (unlikely(delta >= frag_len)) {
                        delta -= frag_len;
                        continue;
                }

                dma = skb_frag_dma_map(tx_ring->dev, frag, delta,
                                       frag_len - delta, DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(tx_ring->dev, dma)))
                        goto error_report_dma_error;

                ena_buf->paddr = dma;
                ena_buf->len = frag_len - delta;
                ena_buf++;
                tx_info->num_of_bufs++;
                delta = 0;
        }

        return 0;

error_report_dma_error:
        u64_stats_update_begin(&tx_ring->syncp);
        tx_ring->tx_stats.dma_mapping_err++;
        u64_stats_update_end(&tx_ring->syncp);
        netdev_warn(adapter->netdev, "failed to map skb\n");

        tx_info->skb = NULL;

        tx_info->num_of_bufs += i;
        ena_unmap_tx_skb(tx_ring, tx_info);

        return -EINVAL;
}

/* Called with netif_tx_lock. */
static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct ena_adapter *adapter = netdev_priv(dev);
        struct ena_tx_buffer *tx_info;
        struct ena_com_tx_ctx ena_tx_ctx;
        struct ena_ring *tx_ring;
        struct netdev_queue *txq;
        void *push_hdr;
        u16 next_to_use, req_id, header_len;
        int qid, rc, nb_hw_desc;

        netif_dbg(adapter, tx_queued, dev, "%s skb %p\n", __func__, skb);
        /*  Determine which tx ring we will be placed on */
        qid = skb_get_queue_mapping(skb);
        tx_ring = &adapter->tx_ring[qid];
        txq = netdev_get_tx_queue(dev, qid);

        rc = ena_check_and_linearize_skb(tx_ring, skb);
        if (unlikely(rc))
                goto error_drop_packet;

        skb_tx_timestamp(skb);

        next_to_use = tx_ring->next_to_use;
        req_id = tx_ring->free_ids[next_to_use];
        tx_info = &tx_ring->tx_buffer_info[req_id];
        tx_info->num_of_bufs = 0;

        WARN(tx_info->skb, "SKB isn't NULL req_id %d\n", req_id);

        rc = ena_tx_map_skb(tx_ring, tx_info, skb, &push_hdr, &header_len);
        if (unlikely(rc))
                goto error_drop_packet;

        memset(&ena_tx_ctx, 0x0, sizeof(struct ena_com_tx_ctx));
        ena_tx_ctx.ena_bufs = tx_info->bufs;
        ena_tx_ctx.push_header = push_hdr;
        ena_tx_ctx.num_bufs = tx_info->num_of_bufs;
        ena_tx_ctx.req_id = req_id;
        ena_tx_ctx.header_len = header_len;

        /* set flags and meta data */
        ena_tx_csum(&ena_tx_ctx, skb);

        if (unlikely(ena_com_is_doorbell_needed(tx_ring->ena_com_io_sq, &ena_tx_ctx))) {
                netif_dbg(adapter, tx_queued, dev,
                          "llq tx max burst size of queue %d achieved, writing doorbell to send burst\n",
                          qid);
                ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
        }

        /* prepare the packet's descriptors to dma engine */
        rc = ena_com_prepare_tx(tx_ring->ena_com_io_sq, &ena_tx_ctx,
                                &nb_hw_desc);

        /* ena_com_prepare_tx() can't fail due to overflow of tx queue,
         * since the number of free descriptors in the queue is checked
         * after sending the previous packet. In case there isn't enough
         * space in the queue for the next packet, it is stopped
         * until there is again enough available space in the queue.
         * All other failure reasons of ena_com_prepare_tx() are fatal
         * and therefore require a device reset.
         */
        if (unlikely(rc)) {
                netif_err(adapter, tx_queued, dev,
                          "failed to prepare tx bufs\n");
                u64_stats_update_begin(&tx_ring->syncp);
                tx_ring->tx_stats.prepare_ctx_err++;
                u64_stats_update_end(&tx_ring->syncp);
                adapter->reset_reason = ENA_REGS_RESET_DRIVER_INVALID_STATE;
                set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
                goto error_unmap_dma;
        }

        netdev_tx_sent_queue(txq, skb->len);

        u64_stats_update_begin(&tx_ring->syncp);
        tx_ring->tx_stats.cnt++;
        tx_ring->tx_stats.bytes += skb->len;
        u64_stats_update_end(&tx_ring->syncp);

        tx_info->tx_descs = nb_hw_desc;
        tx_info->last_jiffies = jiffies;
        tx_info->print_once = 0;

        tx_ring->next_to_use = ENA_TX_RING_IDX_NEXT(next_to_use,
                tx_ring->ring_size);

        /* stop the queue when no more space available, the packet can have up
         * to sgl_size + 2. one for the meta descriptor and one for header
         * (if the header is larger than tx_max_header_size).
         */
        if (unlikely(!ena_com_sq_have_enough_space(tx_ring->ena_com_io_sq,
                                                   tx_ring->sgl_size + 2))) {
                netif_dbg(adapter, tx_queued, dev, "%s stop queue %d\n",
                          __func__, qid);

                netif_tx_stop_queue(txq);
                u64_stats_update_begin(&tx_ring->syncp);
                tx_ring->tx_stats.queue_stop++;
                u64_stats_update_end(&tx_ring->syncp);

                /* There is a rare condition where this function decide to
                 * stop the queue but meanwhile clean_tx_irq updates
                 * next_to_completion and terminates.
                 * The queue will remain stopped forever.
                 * To solve this issue add a mb() to make sure that
                 * netif_tx_stop_queue() write is vissible before checking if
                 * there is additional space in the queue.
                 */
                smp_mb();

                if (ena_com_sq_have_enough_space(tx_ring->ena_com_io_sq,
                                                 ENA_TX_WAKEUP_THRESH)) {
                        netif_tx_wake_queue(txq);
                        u64_stats_update_begin(&tx_ring->syncp);
                        tx_ring->tx_stats.queue_wakeup++;
                        u64_stats_update_end(&tx_ring->syncp);
                }
        }

        if (netif_xmit_stopped(txq) || !netdev_xmit_more()) {
                /* trigger the dma engine. ena_com_write_sq_doorbell()
                 * has a mb
                 */
                ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
                u64_stats_update_begin(&tx_ring->syncp);
                tx_ring->tx_stats.doorbells++;
                u64_stats_update_end(&tx_ring->syncp);
        }

        return NETDEV_TX_OK;

error_unmap_dma:
        ena_unmap_tx_skb(tx_ring, tx_info);
        tx_info->skb = NULL;

error_drop_packet:
        dev_kfree_skb(skb);
        return NETDEV_TX_OK;
}

static u16 ena_select_queue(struct net_device *dev, struct sk_buff *skb,
                            struct net_device *sb_dev)
{
        u16 qid;
        /* we suspect that this is good for in--kernel network services that
         * want to loop incoming skb rx to tx in normal user generated traffic,
         * most probably we will not get to this
         */
        if (skb_rx_queue_recorded(skb))
                qid = skb_get_rx_queue(skb);
        else
                qid = netdev_pick_tx(dev, skb, NULL);

        return qid;
}

static void ena_config_host_info(struct ena_com_dev *ena_dev,
                                 struct pci_dev *pdev)
{
        struct ena_admin_host_info *host_info;
        int rc;

        /* Allocate only the host info */
        rc = ena_com_allocate_host_info(ena_dev);
        if (rc) {
                pr_err("Cannot allocate host info\n");
                return;
        }

        host_info = ena_dev->host_attr.host_info;

        host_info->bdf = (pdev->bus->number << 8) | pdev->devfn;
        host_info->os_type = ENA_ADMIN_OS_LINUX;
        host_info->kernel_ver = LINUX_VERSION_CODE;
        strlcpy(host_info->kernel_ver_str, utsname()->version,
                sizeof(host_info->kernel_ver_str) - 1);
        host_info->os_dist = 0;
        strncpy(host_info->os_dist_str, utsname()->release,
                sizeof(host_info->os_dist_str) - 1);
        host_info->driver_version =
                (DRV_MODULE_VER_MAJOR) |
                (DRV_MODULE_VER_MINOR << ENA_ADMIN_HOST_INFO_MINOR_SHIFT) |
                (DRV_MODULE_VER_SUBMINOR << ENA_ADMIN_HOST_INFO_SUB_MINOR_SHIFT) |
                ("K"[0] << ENA_ADMIN_HOST_INFO_MODULE_TYPE_SHIFT);
        host_info->num_cpus = num_online_cpus();

        rc = ena_com_set_host_attributes(ena_dev);
        if (rc) {
                if (rc == -EOPNOTSUPP)
                        pr_warn("Cannot set host attributes\n");
                else
                        pr_err("Cannot set host attributes\n");

                goto err;
        }

        return;

err:
        ena_com_delete_host_info(ena_dev);
}

static void ena_config_debug_area(struct ena_adapter *adapter)
{
        u32 debug_area_size;
        int rc, ss_count;

        ss_count = ena_get_sset_count(adapter->netdev, ETH_SS_STATS);
        if (ss_count <= 0) {
                netif_err(adapter, drv, adapter->netdev,
                          "SS count is negative\n");
                return;
        }

        /* allocate 32 bytes for each string and 64bit for the value */
        debug_area_size = ss_count * ETH_GSTRING_LEN + sizeof(u64) * ss_count;

        rc = ena_com_allocate_debug_area(adapter->ena_dev, debug_area_size);
        if (rc) {
                pr_err("Cannot allocate debug area\n");
                return;
        }

        rc = ena_com_set_host_attributes(adapter->ena_dev);
        if (rc) {
                if (rc == -EOPNOTSUPP)
                        netif_warn(adapter, drv, adapter->netdev,
                                   "Cannot set host attributes\n");
                else
                        netif_err(adapter, drv, adapter->netdev,
                                  "Cannot set host attributes\n");
                goto err;
        }

        return;
err:
        ena_com_delete_debug_area(adapter->ena_dev);
}

static void ena_get_stats64(struct net_device *netdev,
                            struct rtnl_link_stats64 *stats)
{
        struct ena_adapter *adapter = netdev_priv(netdev);
        struct ena_ring *rx_ring, *tx_ring;
        unsigned int start;
        u64 rx_drops;
        int i;

        if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
                return;

        for (i = 0; i < adapter->num_queues; i++) {
                u64 bytes, packets;

                tx_ring = &adapter->tx_ring[i];

                do {
                        start = u64_stats_fetch_begin_irq(&tx_ring->syncp);
                        packets = tx_ring->tx_stats.cnt;
                        bytes = tx_ring->tx_stats.bytes;
                } while (u64_stats_fetch_retry_irq(&tx_ring->syncp, start));

                stats->tx_packets += packets;
                stats->tx_bytes += bytes;

                rx_ring = &adapter->rx_ring[i];

                do {
                        start = u64_stats_fetch_begin_irq(&rx_ring->syncp);
                        packets = rx_ring->rx_stats.cnt;
                        bytes = rx_ring->rx_stats.bytes;
                } while (u64_stats_fetch_retry_irq(&rx_ring->syncp, start));

                stats->rx_packets += packets;
                stats->rx_bytes += bytes;
        }

        do {
                start = u64_stats_fetch_begin_irq(&adapter->syncp);
                rx_drops = adapter->dev_stats.rx_drops;
        } while (u64_stats_fetch_retry_irq(&adapter->syncp, start));

        stats->rx_dropped = rx_drops;

        stats->multicast = 0;
        stats->collisions = 0;

        stats->rx_length_errors = 0;
        stats->rx_crc_errors = 0;
        stats->rx_frame_errors = 0;
        stats->rx_fifo_errors = 0;
        stats->rx_missed_errors = 0;
        stats->tx_window_errors = 0;

        stats->rx_errors = 0;
        stats->tx_errors = 0;
}

static const struct net_device_ops ena_netdev_ops = {
        .ndo_open               = ena_open,
        .ndo_stop               = ena_close,
        .ndo_start_xmit         = ena_start_xmit,
        .ndo_select_queue       = ena_select_queue,
        .ndo_get_stats64        = ena_get_stats64,
        .ndo_tx_timeout         = ena_tx_timeout,
        .ndo_change_mtu         = ena_change_mtu,
        .ndo_set_mac_address    = NULL,
        .ndo_validate_addr      = eth_validate_addr,
};

static int ena_device_validate_params(struct ena_adapter *adapter,
                                      struct ena_com_dev_get_features_ctx *get_feat_ctx)
{
        struct net_device *netdev = adapter->netdev;
        int rc;

        rc = ether_addr_equal(get_feat_ctx->dev_attr.mac_addr,
                              adapter->mac_addr);
        if (!rc) {
                netif_err(adapter, drv, netdev,
                          "Error, mac address are different\n");
                return -EINVAL;
        }

        if (get_feat_ctx->dev_attr.max_mtu < netdev->mtu) {
                netif_err(adapter, drv, netdev,
                          "Error, device max mtu is smaller than netdev MTU\n");
                return -EINVAL;
        }

        return 0;
}

static int ena_device_init(struct ena_com_dev *ena_dev, struct pci_dev *pdev,
                           struct ena_com_dev_get_features_ctx *get_feat_ctx,
                           bool *wd_state)
{
        struct device *dev = &pdev->dev;
        bool readless_supported;
        u32 aenq_groups;
        int dma_width;
        int rc;

        rc = ena_com_mmio_reg_read_request_init(ena_dev);
        if (rc) {
                dev_err(dev, "failed to init mmio read less\n");
                return rc;
        }

        /* The PCIe configuration space revision id indicate if mmio reg
         * read is disabled
         */
        readless_supported = !(pdev->revision & ENA_MMIO_DISABLE_REG_READ);
        ena_com_set_mmio_read_mode(ena_dev, readless_supported);

        rc = ena_com_dev_reset(ena_dev, ENA_REGS_RESET_NORMAL);
        if (rc) {
                dev_err(dev, "Can not reset device\n");
                goto err_mmio_read_less;
        }

        rc = ena_com_validate_version(ena_dev);
        if (rc) {
                dev_err(dev, "device version is too low\n");
                goto err_mmio_read_less;
        }

        dma_width = ena_com_get_dma_width(ena_dev);
        if (dma_width < 0) {
                dev_err(dev, "Invalid dma width value %d", dma_width);
                rc = dma_width;
                goto err_mmio_read_less;
        }

        rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(dma_width));
        if (rc) {
                dev_err(dev, "pci_set_dma_mask failed 0x%x\n", rc);
                goto err_mmio_read_less;
        }

        rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(dma_width));
        if (rc) {
                dev_err(dev, "err_pci_set_consistent_dma_mask failed 0x%x\n",
                        rc);
                goto err_mmio_read_less;
        }

        /* ENA admin level init */
        rc = ena_com_admin_init(ena_dev, &aenq_handlers);
        if (rc) {
                dev_err(dev,
                        "Can not initialize ena admin queue with device\n");
                goto err_mmio_read_less;
        }

        /* To enable the msix interrupts the driver needs to know the number
         * of queues. So the driver uses polling mode to retrieve this
         * information
         */
        ena_com_set_admin_polling_mode(ena_dev, true);

        ena_config_host_info(ena_dev, pdev);

        /* Get Device Attributes*/
        rc = ena_com_get_dev_attr_feat(ena_dev, get_feat_ctx);
        if (rc) {
                dev_err(dev, "Cannot get attribute for ena device rc=%d\n", rc);
                goto err_admin_init;
        }

        /* Try to turn all the available aenq groups */
        aenq_groups = BIT(ENA_ADMIN_LINK_CHANGE) |
                BIT(ENA_ADMIN_FATAL_ERROR) |
                BIT(ENA_ADMIN_WARNING) |
                BIT(ENA_ADMIN_NOTIFICATION) |
                BIT(ENA_ADMIN_KEEP_ALIVE);

        aenq_groups &= get_feat_ctx->aenq.supported_groups;

        rc = ena_com_set_aenq_config(ena_dev, aenq_groups);
        if (rc) {
                dev_err(dev, "Cannot configure aenq groups rc= %d\n", rc);
                goto err_admin_init;
        }

        *wd_state = !!(aenq_groups & BIT(ENA_ADMIN_KEEP_ALIVE));

        return 0;

err_admin_init:
        ena_com_delete_host_info(ena_dev);
        ena_com_admin_destroy(ena_dev);
err_mmio_read_less:
        ena_com_mmio_reg_read_request_destroy(ena_dev);

        return rc;
}

static int ena_enable_msix_and_set_admin_interrupts(struct ena_adapter *adapter,
                                                    int io_vectors)
{
        struct ena_com_dev *ena_dev = adapter->ena_dev;
        struct device *dev = &adapter->pdev->dev;
        int rc;

        rc = ena_enable_msix(adapter, io_vectors);
        if (rc) {
                dev_err(dev, "Can not reserve msix vectors\n");
                return rc;
        }

        ena_setup_mgmnt_intr(adapter);

        rc = ena_request_mgmnt_irq(adapter);
        if (rc) {
                dev_err(dev, "Can not setup management interrupts\n");
                goto err_disable_msix;
        }

        ena_com_set_admin_polling_mode(ena_dev, false);

        ena_com_admin_aenq_enable(ena_dev);

        return 0;

err_disable_msix:
        ena_disable_msix(adapter);

        return rc;
}

static void ena_destroy_device(struct ena_adapter *adapter, bool graceful)
{
        struct net_device *netdev = adapter->netdev;
        struct ena_com_dev *ena_dev = adapter->ena_dev;
        bool dev_up;

        if (!test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
                return;

        netif_carrier_off(netdev);

        del_timer_sync(&adapter->timer_service);

        dev_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
        adapter->dev_up_before_reset = dev_up;
        if (!graceful)
                ena_com_set_admin_running_state(ena_dev, false);

        if (test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
                ena_down(adapter);

        /* Stop the device from sending AENQ events (in case reset flag is set
         *  and device is up, ena_down() already reset the device.
         */
        if (!(test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags) && dev_up))
                ena_com_dev_reset(adapter->ena_dev, adapter->reset_reason);

        ena_free_mgmnt_irq(adapter);

        ena_disable_msix(adapter);

        ena_com_abort_admin_commands(ena_dev);

        ena_com_wait_for_abort_completion(ena_dev);

        ena_com_admin_destroy(ena_dev);

        ena_com_mmio_reg_read_request_destroy(ena_dev);

        adapter->reset_reason = ENA_REGS_RESET_NORMAL;

        clear_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
        clear_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
}

static int ena_restore_device(struct ena_adapter *adapter)
{
        struct ena_com_dev_get_features_ctx get_feat_ctx;
        struct ena_com_dev *ena_dev = adapter->ena_dev;
        struct pci_dev *pdev = adapter->pdev;
        bool wd_state;
        int rc;

        set_bit(ENA_FLAG_ONGOING_RESET, &adapter->flags);
        rc = ena_device_init(ena_dev, adapter->pdev, &get_feat_ctx, &wd_state);
        if (rc) {
                dev_err(&pdev->dev, "Can not initialize device\n");
                goto err;
        }
        adapter->wd_state = wd_state;

        rc = ena_device_validate_params(adapter, &get_feat_ctx);
        if (rc) {
                dev_err(&pdev->dev, "Validation of device parameters failed\n");
                goto err_device_destroy;
        }

        rc = ena_enable_msix_and_set_admin_interrupts(adapter,
                                                      adapter->num_queues);
        if (rc) {
                dev_err(&pdev->dev, "Enable MSI-X failed\n");
                goto err_device_destroy;
        }
        /* If the interface was up before the reset bring it up */
        if (adapter->dev_up_before_reset) {
                rc = ena_up(adapter);
                if (rc) {
                        dev_err(&pdev->dev, "Failed to create I/O queues\n");
                        goto err_disable_msix;
                }
        }

        set_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);

        clear_bit(ENA_FLAG_ONGOING_RESET, &adapter->flags);
        if (test_bit(ENA_FLAG_LINK_UP, &adapter->flags))
                netif_carrier_on(adapter->netdev);

        mod_timer(&adapter->timer_service, round_jiffies(jiffies + HZ));
        dev_err(&pdev->dev,
                "Device reset completed successfully, Driver info: %s\n",
                version);

        return rc;
err_disable_msix:
        ena_free_mgmnt_irq(adapter);
        ena_disable_msix(adapter);
err_device_destroy:
        ena_com_abort_admin_commands(ena_dev);
        ena_com_wait_for_abort_completion(ena_dev);
        ena_com_admin_destroy(ena_dev);
        ena_com_dev_reset(ena_dev, ENA_REGS_RESET_DRIVER_INVALID_STATE);
        ena_com_mmio_reg_read_request_destroy(ena_dev);
err:
        clear_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
        clear_bit(ENA_FLAG_ONGOING_RESET, &adapter->flags);
        dev_err(&pdev->dev,
                "Reset attempt failed. Can not reset the device\n");

        return rc;
}

static void ena_fw_reset_device(struct work_struct *work)
{
        struct ena_adapter *adapter =
                container_of(work, struct ena_adapter, reset_task);
        struct pci_dev *pdev = adapter->pdev;

        if (unlikely(!test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags))) {
                dev_err(&pdev->dev,
                        "device reset schedule while reset bit is off\n");
                return;
        }
        rtnl_lock();
        ena_destroy_device(adapter, false);
        ena_restore_device(adapter);
        rtnl_unlock();
}

static int check_for_rx_interrupt_queue(struct ena_adapter *adapter,
                                        struct ena_ring *rx_ring)
{
        if (likely(rx_ring->first_interrupt))
                return 0;

        if (ena_com_cq_empty(rx_ring->ena_com_io_cq))
                return 0;

        rx_ring->no_interrupt_event_cnt++;

        if (rx_ring->no_interrupt_event_cnt == ENA_MAX_NO_INTERRUPT_ITERATIONS) {
                netif_err(adapter, rx_err, adapter->netdev,
                          "Potential MSIX issue on Rx side Queue = %d. Reset the device\n",
                          rx_ring->qid);
                adapter->reset_reason = ENA_REGS_RESET_MISS_INTERRUPT;
                smp_mb__before_atomic();
                set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
                return -EIO;
        }

        return 0;
}

static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter,
                                          struct ena_ring *tx_ring)
{
        struct ena_tx_buffer *tx_buf;
        unsigned long last_jiffies;
        u32 missed_tx = 0;
        int i, rc = 0;

        for (i = 0; i < tx_ring->ring_size; i++) {
                tx_buf = &tx_ring->tx_buffer_info[i];
                last_jiffies = tx_buf->last_jiffies;

                if (last_jiffies == 0)
                        /* no pending Tx at this location */
                        continue;

                if (unlikely(!tx_ring->first_interrupt && time_is_before_jiffies(last_jiffies +
                             2 * adapter->missing_tx_completion_to))) {
                        /* If after graceful period interrupt is still not
                         * received, we schedule a reset
                         */
                        netif_err(adapter, tx_err, adapter->netdev,
                                  "Potential MSIX issue on Tx side Queue = %d. Reset the device\n",
                                  tx_ring->qid);
                        adapter->reset_reason = ENA_REGS_RESET_MISS_INTERRUPT;
                        smp_mb__before_atomic();
                        set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
                        return -EIO;
                }

                if (unlikely(time_is_before_jiffies(last_jiffies +
                                adapter->missing_tx_completion_to))) {
                        if (!tx_buf->print_once)
                                netif_notice(adapter, tx_err, adapter->netdev,
                                             "Found a Tx that wasn't completed on time, qid %d, index %d.\n",
                                             tx_ring->qid, i);

                        tx_buf->print_once = 1;
                        missed_tx++;
                }
        }

        if (unlikely(missed_tx > adapter->missing_tx_completion_threshold)) {
                netif_err(adapter, tx_err, adapter->netdev,
                          "The number of lost tx completions is above the threshold (%d > %d). Reset the device\n",
                          missed_tx,
                          adapter->missing_tx_completion_threshold);
                adapter->reset_reason =
                        ENA_REGS_RESET_MISS_TX_CMPL;
                set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
                rc = -EIO;
        }

        u64_stats_update_begin(&tx_ring->syncp);
        tx_ring->tx_stats.missed_tx = missed_tx;
        u64_stats_update_end(&tx_ring->syncp);

        return rc;
}

static void check_for_missing_completions(struct ena_adapter *adapter)
{
        struct ena_ring *tx_ring;
        struct ena_ring *rx_ring;
        int i, budget, rc;

        /* Make sure the driver doesn't turn the device in other process */
        smp_rmb();

        if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
                return;

        if (test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags))
                return;

        if (adapter->missing_tx_completion_to == ENA_HW_HINTS_NO_TIMEOUT)
                return;

        budget = ENA_MONITORED_TX_QUEUES;

        for (i = adapter->last_monitored_tx_qid; i < adapter->num_queues; i++) {
                tx_ring = &adapter->tx_ring[i];
                rx_ring = &adapter->rx_ring[i];

                rc = check_missing_comp_in_tx_queue(adapter, tx_ring);
                if (unlikely(rc))
                        return;

                rc = check_for_rx_interrupt_queue(adapter, rx_ring);
                if (unlikely(rc))
                        return;

                budget--;
                if (!budget)
                        break;
        }

        adapter->last_monitored_tx_qid = i % adapter->num_queues;
}

/* trigger napi schedule after 2 consecutive detections */
#define EMPTY_RX_REFILL 2
/* For the rare case where the device runs out of Rx descriptors and the
 * napi handler failed to refill new Rx descriptors (due to a lack of memory
 * for example).
 * This case will lead to a deadlock:
 * The device won't send interrupts since all the new Rx packets will be dropped
 * The napi handler won't allocate new Rx descriptors so the device will be
 * able to send new packets.
 *
 * This scenario can happen when the kernel's vm.min_free_kbytes is too small.
 * It is recommended to have at least 512MB, with a minimum of 128MB for
 * constrained environment).
 *
 * When such a situation is detected - Reschedule napi
 */
static void check_for_empty_rx_ring(struct ena_adapter *adapter)
{
        struct ena_ring *rx_ring;
        int i, refill_required;

        if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
                return;

        if (test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags))
                return;

        for (i = 0; i < adapter->num_queues; i++) {
                rx_ring = &adapter->rx_ring[i];

                refill_required =
                        ena_com_free_desc(rx_ring->ena_com_io_sq);
                if (unlikely(refill_required == (rx_ring->ring_size - 1))) {
                        rx_ring->empty_rx_queue++;

                        if (rx_ring->empty_rx_queue >= EMPTY_RX_REFILL) {
                                u64_stats_update_begin(&rx_ring->syncp);
                                rx_ring->rx_stats.empty_rx_ring++;
                                u64_stats_update_end(&rx_ring->syncp);

                                netif_err(adapter, drv, adapter->netdev,