/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2009-2012 Cavium, Inc
 */

#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/etherdevice.h>
#include <linux/capability.h>
#include <linux/net_tstamp.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/if_vlan.h>
#include <linux/of_mdio.h>
#include <linux/module.h>
#include <linux/of_net.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/phy.h>
#include <linux/io.h>

#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-mixx-defs.h>
#include <asm/octeon/cvmx-agl-defs.h>

#define DRV_NAME "octeon_mgmt"
#define DRV_VERSION "2.0"
#define DRV_DESCRIPTION \
        "Cavium Networks Octeon MII (management) port Network Driver"

#define OCTEON_MGMT_NAPI_WEIGHT 16

/* Ring sizes that are powers of two allow for more efficient modulo
 * opertions.
 */
#define OCTEON_MGMT_RX_RING_SIZE 512
#define OCTEON_MGMT_TX_RING_SIZE 128

/* Allow 8 bytes for vlan and FCS. */
#define OCTEON_MGMT_RX_HEADROOM (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN)

union mgmt_port_ring_entry {
        u64 d64;
        struct {
#define RING_ENTRY_CODE_DONE 0xf
#define RING_ENTRY_CODE_MORE 0x10
#ifdef __BIG_ENDIAN_BITFIELD
                u64 reserved_62_63:2;
                /* Length of the buffer/packet in bytes */
                u64 len:14;
                /* For TX, signals that the packet should be timestamped */
                u64 tstamp:1;
                /* The RX error code */
                u64 code:7;
                /* Physical address of the buffer */
                u64 addr:40;
#else
                u64 addr:40;
                u64 code:7;
                u64 tstamp:1;
                u64 len:14;
                u64 reserved_62_63:2;
#endif
        } s;
};

#define MIX_ORING1      0x0
#define MIX_ORING2      0x8
#define MIX_IRING1      0x10
#define MIX_IRING2      0x18
#define MIX_CTL         0x20
#define MIX_IRHWM       0x28
#define MIX_IRCNT       0x30
#define MIX_ORHWM       0x38
#define MIX_ORCNT       0x40
#define MIX_ISR         0x48
#define MIX_INTENA      0x50
#define MIX_REMCNT      0x58
#define MIX_BIST        0x78

#define AGL_GMX_PRT_CFG                 0x10
#define AGL_GMX_RX_FRM_CTL              0x18
#define AGL_GMX_RX_FRM_MAX              0x30
#define AGL_GMX_RX_JABBER               0x38
#define AGL_GMX_RX_STATS_CTL            0x50

#define AGL_GMX_RX_STATS_PKTS_DRP       0xb0
#define AGL_GMX_RX_STATS_OCTS_DRP       0xb8
#define AGL_GMX_RX_STATS_PKTS_BAD       0xc0

#define AGL_GMX_RX_ADR_CTL              0x100
#define AGL_GMX_RX_ADR_CAM_EN           0x108
#define AGL_GMX_RX_ADR_CAM0             0x180
#define AGL_GMX_RX_ADR_CAM1             0x188
#define AGL_GMX_RX_ADR_CAM2             0x190
#define AGL_GMX_RX_ADR_CAM3             0x198
#define AGL_GMX_RX_ADR_CAM4             0x1a0
#define AGL_GMX_RX_ADR_CAM5             0x1a8

#define AGL_GMX_TX_CLK                  0x208
#define AGL_GMX_TX_STATS_CTL            0x268
#define AGL_GMX_TX_CTL                  0x270
#define AGL_GMX_TX_STAT0                0x280
#define AGL_GMX_TX_STAT1                0x288
#define AGL_GMX_TX_STAT2                0x290
#define AGL_GMX_TX_STAT3                0x298
#define AGL_GMX_TX_STAT4                0x2a0
#define AGL_GMX_TX_STAT5                0x2a8
#define AGL_GMX_TX_STAT6                0x2b0
#define AGL_GMX_TX_STAT7                0x2b8
#define AGL_GMX_TX_STAT8                0x2c0
#define AGL_GMX_TX_STAT9                0x2c8

struct octeon_mgmt {
        struct net_device *netdev;
        u64 mix;
        u64 agl;
        u64 agl_prt_ctl;
        int port;
        int irq;
        bool has_rx_tstamp;
        u64 *tx_ring;
        dma_addr_t tx_ring_handle;
        unsigned int tx_next;
        unsigned int tx_next_clean;
        unsigned int tx_current_fill;
        /* The tx_list lock also protects the ring related variables */
        struct sk_buff_head tx_list;

        /* RX variables only touched in napi_poll.  No locking necessary. */
        u64 *rx_ring;
        dma_addr_t rx_ring_handle;
        unsigned int rx_next;
        unsigned int rx_next_fill;
        unsigned int rx_current_fill;
        struct sk_buff_head rx_list;

        spinlock_t lock;
        unsigned int last_duplex;
        unsigned int last_link;
        unsigned int last_speed;
        struct device *dev;
        struct napi_struct napi;
        struct tasklet_struct tx_clean_tasklet;
        struct device_node *phy_np;
        resource_size_t mix_phys;
        resource_size_t mix_size;
        resource_size_t agl_phys;
        resource_size_t agl_size;
        resource_size_t agl_prt_ctl_phys;
        resource_size_t agl_prt_ctl_size;
};

static void octeon_mgmt_set_rx_irq(struct octeon_mgmt *p, int enable)
{
        union cvmx_mixx_intena mix_intena;
        unsigned long flags;

        spin_lock_irqsave(&p->lock, flags);
        mix_intena.u64 = cvmx_read_csr(p->mix + MIX_INTENA);
        mix_intena.s.ithena = enable ? 1 : 0;
        cvmx_write_csr(p->mix + MIX_INTENA, mix_intena.u64);
        spin_unlock_irqrestore(&p->lock, flags);
}

static void octeon_mgmt_set_tx_irq(struct octeon_mgmt *p, int enable)
{
        union cvmx_mixx_intena mix_intena;
        unsigned long flags;

        spin_lock_irqsave(&p->lock, flags);
        mix_intena.u64 = cvmx_read_csr(p->mix + MIX_INTENA);
        mix_intena.s.othena = enable ? 1 : 0;
        cvmx_write_csr(p->mix + MIX_INTENA, mix_intena.u64);
        spin_unlock_irqrestore(&p->lock, flags);
}

static void octeon_mgmt_enable_rx_irq(struct octeon_mgmt *p)
{
        octeon_mgmt_set_rx_irq(p, 1);
}

static void octeon_mgmt_disable_rx_irq(struct octeon_mgmt *p)
{
        octeon_mgmt_set_rx_irq(p, 0);
}

static void octeon_mgmt_enable_tx_irq(struct octeon_mgmt *p)
{
        octeon_mgmt_set_tx_irq(p, 1);
}

static void octeon_mgmt_disable_tx_irq(struct octeon_mgmt *p)
{
        octeon_mgmt_set_tx_irq(p, 0);
}

static unsigned int ring_max_fill(unsigned int ring_size)
{
        return ring_size - 8;
}

static unsigned int ring_size_to_bytes(unsigned int ring_size)
{
        return ring_size * sizeof(union mgmt_port_ring_entry);
}

static void octeon_mgmt_rx_fill_ring(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);

        while (p->rx_current_fill < ring_max_fill(OCTEON_MGMT_RX_RING_SIZE)) {
                unsigned int size;
                union mgmt_port_ring_entry re;
                struct sk_buff *skb;

                /* CN56XX pass 1 needs 8 bytes of padding.  */
                size = netdev->mtu + OCTEON_MGMT_RX_HEADROOM + 8 + NET_IP_ALIGN;

                skb = netdev_alloc_skb(netdev, size);
                if (!skb)
                        break;
                skb_reserve(skb, NET_IP_ALIGN);
                __skb_queue_tail(&p->rx_list, skb);

                re.d64 = 0;
                re.s.len = size;
                re.s.addr = dma_map_single(p->dev, skb->data,
                                           size,
                                           DMA_FROM_DEVICE);

                /* Put it in the ring.  */
                p->rx_ring[p->rx_next_fill] = re.d64;
                dma_sync_single_for_device(p->dev, p->rx_ring_handle,
                                           ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE),
                                           DMA_BIDIRECTIONAL);
                p->rx_next_fill =
                        (p->rx_next_fill + 1) % OCTEON_MGMT_RX_RING_SIZE;
                p->rx_current_fill++;
                /* Ring the bell.  */
                cvmx_write_csr(p->mix + MIX_IRING2, 1);
        }
}

static void octeon_mgmt_clean_tx_buffers(struct octeon_mgmt *p)
{
        union cvmx_mixx_orcnt mix_orcnt;
        union mgmt_port_ring_entry re;
        struct sk_buff *skb;
        int cleaned = 0;
        unsigned long flags;

        mix_orcnt.u64 = cvmx_read_csr(p->mix + MIX_ORCNT);
        while (mix_orcnt.s.orcnt) {
                spin_lock_irqsave(&p->tx_list.lock, flags);

                mix_orcnt.u64 = cvmx_read_csr(p->mix + MIX_ORCNT);

                if (mix_orcnt.s.orcnt == 0) {
                        spin_unlock_irqrestore(&p->tx_list.lock, flags);
                        break;
                }

                dma_sync_single_for_cpu(p->dev, p->tx_ring_handle,
                                        ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
                                        DMA_BIDIRECTIONAL);

                re.d64 = p->tx_ring[p->tx_next_clean];
                p->tx_next_clean =
                        (p->tx_next_clean + 1) % OCTEON_MGMT_TX_RING_SIZE;
                skb = __skb_dequeue(&p->tx_list);

                mix_orcnt.u64 = 0;
                mix_orcnt.s.orcnt = 1;

                /* Acknowledge to hardware that we have the buffer.  */
                cvmx_write_csr(p->mix + MIX_ORCNT, mix_orcnt.u64);
                p->tx_current_fill--;

                spin_unlock_irqrestore(&p->tx_list.lock, flags);

                dma_unmap_single(p->dev, re.s.addr, re.s.len,
                                 DMA_TO_DEVICE);

                /* Read the hardware TX timestamp if one was recorded */
                if (unlikely(re.s.tstamp)) {
                        struct skb_shared_hwtstamps ts;
                        u64 ns;

                        memset(&ts, 0, sizeof(ts));
                        /* Read the timestamp */
                        ns = cvmx_read_csr(CVMX_MIXX_TSTAMP(p->port));
                        /* Remove the timestamp from the FIFO */
                        cvmx_write_csr(CVMX_MIXX_TSCTL(p->port), 0);
                        /* Tell the kernel about the timestamp */
                        ts.hwtstamp = ns_to_ktime(ns);
                        skb_tstamp_tx(skb, &ts);
                }

                dev_kfree_skb_any(skb);
                cleaned++;

                mix_orcnt.u64 = cvmx_read_csr(p->mix + MIX_ORCNT);
        }

        if (cleaned && netif_queue_stopped(p->netdev))
                netif_wake_queue(p->netdev);
}

static void octeon_mgmt_clean_tx_tasklet(unsigned long arg)
{
        struct octeon_mgmt *p = (struct octeon_mgmt *)arg;
        octeon_mgmt_clean_tx_buffers(p);
        octeon_mgmt_enable_tx_irq(p);
}

static void octeon_mgmt_update_rx_stats(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        unsigned long flags;
        u64 drop, bad;

        /* These reads also clear the count registers.  */
        drop = cvmx_read_csr(p->agl + AGL_GMX_RX_STATS_PKTS_DRP);
        bad = cvmx_read_csr(p->agl + AGL_GMX_RX_STATS_PKTS_BAD);

        if (drop || bad) {
                /* Do an atomic update. */
                spin_lock_irqsave(&p->lock, flags);
                netdev->stats.rx_errors += bad;
                netdev->stats.rx_dropped += drop;
                spin_unlock_irqrestore(&p->lock, flags);
        }
}

static void octeon_mgmt_update_tx_stats(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        unsigned long flags;

        union cvmx_agl_gmx_txx_stat0 s0;
        union cvmx_agl_gmx_txx_stat1 s1;

        /* These reads also clear the count registers.  */
        s0.u64 = cvmx_read_csr(p->agl + AGL_GMX_TX_STAT0);
        s1.u64 = cvmx_read_csr(p->agl + AGL_GMX_TX_STAT1);

        if (s0.s.xsdef || s0.s.xscol || s1.s.scol || s1.s.mcol) {
                /* Do an atomic update. */
                spin_lock_irqsave(&p->lock, flags);
                netdev->stats.tx_errors += s0.s.xsdef + s0.s.xscol;
                netdev->stats.collisions += s1.s.scol + s1.s.mcol;
                spin_unlock_irqrestore(&p->lock, flags);
        }
}

/*
 * Dequeue a receive skb and its corresponding ring entry.  The ring
 * entry is returned, *pskb is updated to point to the skb.
 */
static u64 octeon_mgmt_dequeue_rx_buffer(struct octeon_mgmt *p,
                                         struct sk_buff **pskb)
{
        union mgmt_port_ring_entry re;

        dma_sync_single_for_cpu(p->dev, p->rx_ring_handle,
                                ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE),
                                DMA_BIDIRECTIONAL);

        re.d64 = p->rx_ring[p->rx_next];
        p->rx_next = (p->rx_next + 1) % OCTEON_MGMT_RX_RING_SIZE;
        p->rx_current_fill--;
        *pskb = __skb_dequeue(&p->rx_list);

        dma_unmap_single(p->dev, re.s.addr,
                         ETH_FRAME_LEN + OCTEON_MGMT_RX_HEADROOM,
                         DMA_FROM_DEVICE);

        return re.d64;
}


static int octeon_mgmt_receive_one(struct octeon_mgmt *p)
{
        struct net_device *netdev = p->netdev;
        union cvmx_mixx_ircnt mix_ircnt;
        union mgmt_port_ring_entry re;
        struct sk_buff *skb;
        struct sk_buff *skb2;
        struct sk_buff *skb_new;
        union mgmt_port_ring_entry re2;
        int rc = 1;


        re.d64 = octeon_mgmt_dequeue_rx_buffer(p, &skb);
        if (likely(re.s.code == RING_ENTRY_CODE_DONE)) {
                /* A good packet, send it up. */
                skb_put(skb, re.s.len);
good:
                /* Process the RX timestamp if it was recorded */
                if (p->has_rx_tstamp) {
                        /* The first 8 bytes are the timestamp */
                        u64 ns = *(u64 *)skb->data;
                        struct skb_shared_hwtstamps *ts;
                        ts = skb_hwtstamps(skb);
                        ts->hwtstamp = ns_to_ktime(ns);
                        __skb_pull(skb, 8);
                }
                skb->protocol = eth_type_trans(skb, netdev);
                netdev->stats.rx_packets++;
                netdev->stats.rx_bytes += skb->len;
                netif_receive_skb(skb);
                rc = 0;
        } else if (re.s.code == RING_ENTRY_CODE_MORE) {
                /* Packet split across skbs.  This can happen if we
                 * increase the MTU.  Buffers that are already in the
                 * rx ring can then end up being too small.  As the rx
                 * ring is refilled, buffers sized for the new MTU
                 * will be used and we should go back to the normal
                 * non-split case.
                 */
                skb_put(skb, re.s.len);
                do {
                        re2.d64 = octeon_mgmt_dequeue_rx_buffer(p, &skb2);
                        if (re2.s.code != RING_ENTRY_CODE_MORE
                                && re2.s.code != RING_ENTRY_CODE_DONE)
                                goto split_error;
                        skb_put(skb2,  re2.s.len);
                        skb_new = skb_copy_expand(skb, 0, skb2->len,
                                                  GFP_ATOMIC);
                        if (!skb_new)
                                goto split_error;
                        if (skb_copy_bits(skb2, 0, skb_tail_pointer(skb_new),
                                          skb2->len))
                                goto split_error;
                        skb_put(skb_new, skb2->len);
                        dev_kfree_skb_any(skb);
                        dev_kfree_skb_any(skb2);
                        skb = skb_new;
                } while (re2.s.code == RING_ENTRY_CODE_MORE);
                goto good;
        } else {
                /* Some other error, discard it. */
                dev_kfree_skb_any(skb);
                /* Error statistics are accumulated in
                 * octeon_mgmt_update_rx_stats.
                 */
        }
        goto done;
split_error:
        /* Discard the whole mess. */
        dev_kfree_skb_any(skb);
        dev_kfree_skb_any(skb2);
        while (re2.s.code == RING_ENTRY_CODE_MORE) {
                re2.d64 = octeon_mgmt_dequeue_rx_buffer(p, &skb2);
                dev_kfree_skb_any(skb2);
        }
        netdev->stats.rx_errors++;

done:
        /* Tell the hardware we processed a packet.  */
        mix_ircnt.u64 = 0;
        mix_ircnt.s.ircnt = 1;
        cvmx_write_csr(p->mix + MIX_IRCNT, mix_ircnt.u64);
        return rc;
}

static int octeon_mgmt_receive_packets(struct octeon_mgmt *p, int budget)
{
        unsigned int work_done = 0;
        union cvmx_mixx_ircnt mix_ircnt;
        int rc;

        mix_ircnt.u64 = cvmx_read_csr(p->mix + MIX_IRCNT);
        while (work_done < budget && mix_ircnt.s.ircnt) {

                rc = octeon_mgmt_receive_one(p);
                if (!rc)
                        work_done++;

                /* Check for more packets. */
                mix_ircnt.u64 = cvmx_read_csr(p->mix + MIX_IRCNT);
        }

        octeon_mgmt_rx_fill_ring(p->netdev);

        return work_done;
}

static int octeon_mgmt_napi_poll(struct napi_struct *napi, int budget)
{
        struct octeon_mgmt *p = container_of(napi, struct octeon_mgmt, napi);
        struct net_device *netdev = p->netdev;
        unsigned int work_done = 0;

        work_done = octeon_mgmt_receive_packets(p, budget);

        if (work_done < budget) {
                /* We stopped because no more packets were available. */
                napi_complete(napi);
                octeon_mgmt_enable_rx_irq(p);
        }
        octeon_mgmt_update_rx_stats(netdev);

        return work_done;
}

/* Reset the hardware to clean state.  */
static void octeon_mgmt_reset_hw(struct octeon_mgmt *p)
{
        union cvmx_mixx_ctl mix_ctl;
        union cvmx_mixx_bist mix_bist;
        union cvmx_agl_gmx_bist agl_gmx_bist;

        mix_ctl.u64 = 0;
        cvmx_write_csr(p->mix + MIX_CTL, mix_ctl.u64);
        do {
                mix_ctl.u64 = cvmx_read_csr(p->mix + MIX_CTL);
        } while (mix_ctl.s.busy);
        mix_ctl.s.reset = 1;
        cvmx_write_csr(p->mix + MIX_CTL, mix_ctl.u64);
        cvmx_read_csr(p->mix + MIX_CTL);
        octeon_io_clk_delay(64);

        mix_bist.u64 = cvmx_read_csr(p->mix + MIX_BIST);
        if (mix_bist.u64)
                dev_warn(p->dev, "MIX failed BIST (0x%016llx)\n",
                        (unsigned long long)mix_bist.u64);

        agl_gmx_bist.u64 = cvmx_read_csr(CVMX_AGL_GMX_BIST);
        if (agl_gmx_bist.u64)
                dev_warn(p->dev, "AGL failed BIST (0x%016llx)\n",
                         (unsigned long long)agl_gmx_bist.u64);
}

struct octeon_mgmt_cam_state {
        u64 cam[6];
        u64 cam_mask;
        int cam_index;
};

static void octeon_mgmt_cam_state_add(struct octeon_mgmt_cam_state *cs,
                                      unsigned char *addr)
{
        int i;

        for (i = 0; i < 6; i++)
                cs->cam[i] |= (u64)addr[i] << (8 * (cs->cam_index));
        cs->cam_mask |= (1ULL << cs->cam_index);
        cs->cam_index++;
}

static void octeon_mgmt_set_rx_filtering(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        union cvmx_agl_gmx_rxx_adr_ctl adr_ctl;
        union cvmx_agl_gmx_prtx_cfg agl_gmx_prtx;
        unsigned long flags;
        unsigned int prev_packet_enable;
        unsigned int cam_mode = 1; /* 1 - Accept on CAM match */
        unsigned int multicast_mode = 1; /* 1 - Reject all multicast.  */
        struct octeon_mgmt_cam_state cam_state;
        struct netdev_hw_addr *ha;
        int available_cam_entries;

        memset(&cam_state, 0, sizeof(cam_state));

        if ((netdev->flags & IFF_PROMISC) || netdev->uc.count > 7) {
                cam_mode = 0;
                available_cam_entries = 8;
        } else {
                /* One CAM entry for the primary address, leaves seven
                 * for the secondary addresses.
                 */
                available_cam_entries = 7 - netdev->uc.count;
        }

        if (netdev->flags & IFF_MULTICAST) {
                if (cam_mode == 0 || (netdev->flags & IFF_ALLMULTI) ||
                    netdev_mc_count(netdev) > available_cam_entries)
                        multicast_mode = 2; /* 2 - Accept all multicast.  */
                else
                        multicast_mode = 0; /* 0 - Use CAM.  */
        }

        if (cam_mode == 1) {
                /* Add primary address. */
                octeon_mgmt_cam_state_add(&cam_state, netdev->dev_addr);
                netdev_for_each_uc_addr(ha, netdev)
                        octeon_mgmt_cam_state_add(&cam_state, ha->addr);
        }
        if (multicast_mode == 0) {
                netdev_for_each_mc_addr(ha, netdev)
                        octeon_mgmt_cam_state_add(&cam_state, ha->addr);
        }

        spin_lock_irqsave(&p->lock, flags);

        /* Disable packet I/O. */
        agl_gmx_prtx.u64 = cvmx_read_csr(p->agl + AGL_GMX_PRT_CFG);
        prev_packet_enable = agl_gmx_prtx.s.en;
        agl_gmx_prtx.s.en = 0;
        cvmx_write_csr(p->agl + AGL_GMX_PRT_CFG, agl_gmx_prtx.u64);

        adr_ctl.u64 = 0;
        adr_ctl.s.cam_mode = cam_mode;
        adr_ctl.s.mcst = multicast_mode;
        adr_ctl.s.bcst = 1;     /* Allow broadcast */

        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CTL, adr_ctl.u64);

        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM0, cam_state.cam[0]);
        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM1, cam_state.cam[1]);
        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM2, cam_state.cam[2]);
        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM3, cam_state.cam[3]);
        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM4, cam_state.cam[4]);
        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM5, cam_state.cam[5]);
        cvmx_write_csr(p->agl + AGL_GMX_RX_ADR_CAM_EN, cam_state.cam_mask);

        /* Restore packet I/O. */
        agl_gmx_prtx.s.en = prev_packet_enable;
        cvmx_write_csr(p->agl + AGL_GMX_PRT_CFG, agl_gmx_prtx.u64);

        spin_unlock_irqrestore(&p->lock, flags);
}

static int octeon_mgmt_set_mac_address(struct net_device *netdev, void *addr)
{
        int r = eth_mac_addr(netdev, addr);

        if (r)
                return r;

        octeon_mgmt_set_rx_filtering(netdev);

        return 0;
}

static int octeon_mgmt_change_mtu(struct net_device *netdev, int new_mtu)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        int size_without_fcs = new_mtu + OCTEON_MGMT_RX_HEADROOM;

        /* Limit the MTU to make sure the ethernet packets are between
         * 64 bytes and 16383 bytes.
         */
        if (size_without_fcs < 64 || size_without_fcs > 16383) {
                dev_warn(p->dev, "MTU must be between %d and %d.\n",
                         64 - OCTEON_MGMT_RX_HEADROOM,
                         16383 - OCTEON_MGMT_RX_HEADROOM);
                return -EINVAL;
        }

        netdev->mtu = new_mtu;

        cvmx_write_csr(p->agl + AGL_GMX_RX_FRM_MAX, size_without_fcs);
        cvmx_write_csr(p->agl + AGL_GMX_RX_JABBER,
                       (size_without_fcs + 7) & 0xfff8);

        return 0;
}

static irqreturn_t octeon_mgmt_interrupt(int cpl, void *dev_id)
{
        struct net_device *netdev = dev_id;
        struct octeon_mgmt *p = netdev_priv(netdev);
        union cvmx_mixx_isr mixx_isr;

        mixx_isr.u64 = cvmx_read_csr(p->mix + MIX_ISR);

        /* Clear any pending interrupts */
        cvmx_write_csr(p->mix + MIX_ISR, mixx_isr.u64);
        cvmx_read_csr(p->mix + MIX_ISR);

        if (mixx_isr.s.irthresh) {
                octeon_mgmt_disable_rx_irq(p);
                napi_schedule(&p->napi);
        }
        if (mixx_isr.s.orthresh) {
                octeon_mgmt_disable_tx_irq(p);
                tasklet_schedule(&p->tx_clean_tasklet);
        }

        return IRQ_HANDLED;
}

static int octeon_mgmt_ioctl_hwtstamp(struct net_device *netdev,
                                      struct ifreq *rq, int cmd)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        struct hwtstamp_config config;
        union cvmx_mio_ptp_clock_cfg ptp;
        union cvmx_agl_gmx_rxx_frm_ctl rxx_frm_ctl;
        bool have_hw_timestamps = false;

        if (copy_from_user(&config, rq->ifr_data, sizeof(config)))
                return -EFAULT;

        if (config.flags) /* reserved for future extensions */
                return -EINVAL;

        /* Check the status of hardware for tiemstamps */
        if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                /* Get the current state of the PTP clock */
                ptp.u64 = cvmx_read_csr(CVMX_MIO_PTP_CLOCK_CFG);
                if (!ptp.s.ext_clk_en) {
                        /* The clock has not been configured to use an
                         * external source.  Program it to use the main clock
                         * reference.
                         */
                        u64 clock_comp = (NSEC_PER_SEC << 32) / octeon_get_io_clock_rate();
                        if (!ptp.s.ptp_en)
                                cvmx_write_csr(CVMX_MIO_PTP_CLOCK_COMP, clock_comp);
                        pr_info("PTP Clock: Using sclk reference at %lld Hz\n",
                                (NSEC_PER_SEC << 32) / clock_comp);
                } else {
                        /* The clock is already programmed to use a GPIO */
                        u64 clock_comp = cvmx_read_csr(CVMX_MIO_PTP_CLOCK_COMP);
                        pr_info("PTP Clock: Using GPIO %d at %lld Hz\n",
                                ptp.s.ext_clk_in,
                                (NSEC_PER_SEC << 32) / clock_comp);
                }

                /* Enable the clock if it wasn't done already */
                if (!ptp.s.ptp_en) {
                        ptp.s.ptp_en = 1;
                        cvmx_write_csr(CVMX_MIO_PTP_CLOCK_CFG, ptp.u64);
                }
                have_hw_timestamps = true;
        }

        if (!have_hw_timestamps)
                return -EINVAL;

        switch (config.tx_type) {
        case HWTSTAMP_TX_OFF:
        case HWTSTAMP_TX_ON:
                break;
        default:
                return -ERANGE;
        }

        switch (config.rx_filter) {
        case HWTSTAMP_FILTER_NONE:
                p->has_rx_tstamp = false;
                rxx_frm_ctl.u64 = cvmx_read_csr(p->agl + AGL_GMX_RX_FRM_CTL);
                rxx_frm_ctl.s.ptp_mode = 0;
                cvmx_write_csr(p->agl + AGL_GMX_RX_FRM_CTL, rxx_frm_ctl.u64);
                break;
        case HWTSTAMP_FILTER_ALL:
        case HWTSTAMP_FILTER_SOME:
        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
                p->has_rx_tstamp = have_hw_timestamps;
                config.rx_filter = HWTSTAMP_FILTER_ALL;
                if (p->has_rx_tstamp) {
                        rxx_frm_ctl.u64 = cvmx_read_csr(p->agl + AGL_GMX_RX_FRM_CTL);
                        rxx_frm_ctl.s.ptp_mode = 1;
                        cvmx_write_csr(p->agl + AGL_GMX_RX_FRM_CTL, rxx_frm_ctl.u64);
                }
                break;
        default:
                return -ERANGE;
        }

        if (copy_to_user(rq->ifr_data, &config, sizeof(config)))
                return -EFAULT;

        return 0;
}

static int octeon_mgmt_ioctl(struct net_device *netdev,
                             struct ifreq *rq, int cmd)
{
        switch (cmd) {
        case SIOCSHWTSTAMP:
                return octeon_mgmt_ioctl_hwtstamp(netdev, rq, cmd);
        default:
                if (netdev->phydev)
                        return phy_mii_ioctl(netdev->phydev, rq, cmd);
                return -EINVAL;
        }
}

static void octeon_mgmt_disable_link(struct octeon_mgmt *p)
{
        union cvmx_agl_gmx_prtx_cfg prtx_cfg;

        /* Disable GMX before we make any changes. */
        prtx_cfg.u64 = cvmx_read_csr(p->agl + AGL_GMX_PRT_CFG);
        prtx_cfg.s.en = 0;
        prtx_cfg.s.tx_en = 0;
        prtx_cfg.s.rx_en = 0;
        cvmx_write_csr(p->agl + AGL_GMX_PRT_CFG, prtx_cfg.u64);

        if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                int i;
                for (i = 0; i < 10; i++) {
                        prtx_cfg.u64 = cvmx_read_csr(p->agl + AGL_GMX_PRT_CFG);
                        if (prtx_cfg.s.tx_idle == 1 || prtx_cfg.s.rx_idle == 1)
                                break;
                        mdelay(1);
                        i++;
                }
        }
}

static void octeon_mgmt_enable_link(struct octeon_mgmt *p)
{
        union cvmx_agl_gmx_prtx_cfg prtx_cfg;

        /* Restore the GMX enable state only if link is set */
        prtx_cfg.u64 = cvmx_read_csr(p->agl + AGL_GMX_PRT_CFG);
        prtx_cfg.s.tx_en = 1;
        prtx_cfg.s.rx_en = 1;
        prtx_cfg.s.en = 1;
        cvmx_write_csr(p->agl + AGL_GMX_PRT_CFG, prtx_cfg.u64);
}

static void octeon_mgmt_update_link(struct octeon_mgmt *p)
{
        struct net_device *ndev = p->netdev;
        struct phy_device *phydev = ndev->phydev;
        union cvmx_agl_gmx_prtx_cfg prtx_cfg;

        prtx_cfg.u64 = cvmx_read_csr(p->agl + AGL_GMX_PRT_CFG);

        if (!phydev->link)
                prtx_cfg.s.duplex = 1;
        else
                prtx_cfg.s.duplex = phydev->duplex;

        switch (phydev->speed) {
        case 10:
                prtx_cfg.s.speed = 0;
                prtx_cfg.s.slottime = 0;

                if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                        prtx_cfg.s.burst = 1;
                        prtx_cfg.s.speed_msb = 1;
                }
                break;
        case 100:
                prtx_cfg.s.speed = 0;
                prtx_cfg.s.slottime = 0;

                if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                        prtx_cfg.s.burst = 1;
                        prtx_cfg.s.speed_msb = 0;
                }
                break;
        case 1000:
                /* 1000 MBits is only supported on 6XXX chips */
                if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                        prtx_cfg.s.speed = 1;
                        prtx_cfg.s.speed_msb = 0;
                        /* Only matters for half-duplex */
                        prtx_cfg.s.slottime = 1;
                        prtx_cfg.s.burst = phydev->duplex;
                }
                break;
        case 0:  /* No link */
        default:
                break;
        }

        /* Write the new GMX setting with the port still disabled. */
        cvmx_write_csr(p->agl + AGL_GMX_PRT_CFG, prtx_cfg.u64);

        /* Read GMX CFG again to make sure the config is completed. */
        prtx_cfg.u64 = cvmx_read_csr(p->agl + AGL_GMX_PRT_CFG);

        if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                union cvmx_agl_gmx_txx_clk agl_clk;
                union cvmx_agl_prtx_ctl prtx_ctl;

                prtx_ctl.u64 = cvmx_read_csr(p->agl_prt_ctl);
                agl_clk.u64 = cvmx_read_csr(p->agl + AGL_GMX_TX_CLK);
                /* MII (both speeds) and RGMII 1000 speed. */
                agl_clk.s.clk_cnt = 1;
                if (prtx_ctl.s.mode == 0) { /* RGMII mode */
                        if (phydev->speed == 10)
                                agl_clk.s.clk_cnt = 50;
                        else if (phydev->speed == 100)
                                agl_clk.s.clk_cnt = 5;
                }
                cvmx_write_csr(p->agl + AGL_GMX_TX_CLK, agl_clk.u64);
        }
}

static void octeon_mgmt_adjust_link(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        struct phy_device *phydev = netdev->phydev;
        unsigned long flags;
        int link_changed = 0;

        if (!phydev)
                return;

        spin_lock_irqsave(&p->lock, flags);


        if (!phydev->link && p->last_link)
                link_changed = -1;

        if (phydev->link &&
            (p->last_duplex != phydev->duplex ||
             p->last_link != phydev->link ||
             p->last_speed != phydev->speed)) {
                octeon_mgmt_disable_link(p);
                link_changed = 1;
                octeon_mgmt_update_link(p);
                octeon_mgmt_enable_link(p);
        }

        p->last_link = phydev->link;
        p->last_speed = phydev->speed;
        p->last_duplex = phydev->duplex;

        spin_unlock_irqrestore(&p->lock, flags);

        if (link_changed != 0) {
                if (link_changed > 0) {
                        pr_info("%s: Link is up - %d/%s\n", netdev->name,
                                phydev->speed,
                                phydev->duplex == DUPLEX_FULL ?
                                "Full" : "Half");
                } else {
                        pr_info("%s: Link is down\n", netdev->name);
                }
        }
}

static int octeon_mgmt_init_phy(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        struct phy_device *phydev = NULL;

        if (octeon_is_simulation() || p->phy_np == NULL) {
                /* No PHYs in the simulator. */
                netif_carrier_on(netdev);
                return 0;
        }

        phydev = of_phy_connect(netdev, p->phy_np,
                                octeon_mgmt_adjust_link, 0,
                                PHY_INTERFACE_MODE_MII);

        if (!phydev)
                return -ENODEV;

        return 0;
}

static int octeon_mgmt_open(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        union cvmx_mixx_ctl mix_ctl;
        union cvmx_agl_gmx_inf_mode agl_gmx_inf_mode;
        union cvmx_mixx_oring1 oring1;
        union cvmx_mixx_iring1 iring1;
        union cvmx_agl_gmx_rxx_frm_ctl rxx_frm_ctl;
        union cvmx_mixx_irhwm mix_irhwm;
        union cvmx_mixx_orhwm mix_orhwm;
        union cvmx_mixx_intena mix_intena;
        struct sockaddr sa;

        /* Allocate ring buffers.  */
        p->tx_ring = kzalloc(ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
                             GFP_KERNEL);
        if (!p->tx_ring)
                return -ENOMEM;
        p->tx_ring_handle =
                dma_map_single(p->dev, p->tx_ring,
                               ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
                               DMA_BIDIRECTIONAL);
        p->tx_next = 0;
        p->tx_next_clean = 0;
        p->tx_current_fill = 0;


        p->rx_ring = kzalloc(ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE),
                             GFP_KERNEL);
        if (!p->rx_ring)
                goto err_nomem;

        p->rx_ring_handle =
                dma_map_single(p->dev, p->rx_ring,
                               ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE),
                               DMA_BIDIRECTIONAL);

        p->rx_next = 0;
        p->rx_next_fill = 0;
        p->rx_current_fill = 0;

        octeon_mgmt_reset_hw(p);

        mix_ctl.u64 = cvmx_read_csr(p->mix + MIX_CTL);

        /* Bring it out of reset if needed. */
        if (mix_ctl.s.reset) {
                mix_ctl.s.reset = 0;
                cvmx_write_csr(p->mix + MIX_CTL, mix_ctl.u64);
                do {
                        mix_ctl.u64 = cvmx_read_csr(p->mix + MIX_CTL);
                } while (mix_ctl.s.reset);
        }

        if (OCTEON_IS_MODEL(OCTEON_CN5XXX)) {
                agl_gmx_inf_mode.u64 = 0;
                agl_gmx_inf_mode.s.en = 1;
                cvmx_write_csr(CVMX_AGL_GMX_INF_MODE, agl_gmx_inf_mode.u64);
        }
        if (OCTEON_IS_MODEL(OCTEON_CN56XX_PASS1_X)
                || OCTEON_IS_MODEL(OCTEON_CN52XX_PASS1_X)) {
                /* Force compensation values, as they are not
                 * determined properly by HW
                 */
                union cvmx_agl_gmx_drv_ctl drv_ctl;

                drv_ctl.u64 = cvmx_read_csr(CVMX_AGL_GMX_DRV_CTL);
                if (p->port) {
                        drv_ctl.s.byp_en1 = 1;
                        drv_ctl.s.nctl1 = 6;
                        drv_ctl.s.pctl1 = 6;
                } else {
                        drv_ctl.s.byp_en = 1;
                        drv_ctl.s.nctl = 6;
                        drv_ctl.s.pctl = 6;
                }
                cvmx_write_csr(CVMX_AGL_GMX_DRV_CTL, drv_ctl.u64);
        }

        oring1.u64 = 0;
        oring1.s.obase = p->tx_ring_handle >> 3;
        oring1.s.osize = OCTEON_MGMT_TX_RING_SIZE;
        cvmx_write_csr(p->mix + MIX_ORING1, oring1.u64);

        iring1.u64 = 0;
        iring1.s.ibase = p->rx_ring_handle >> 3;
        iring1.s.isize = OCTEON_MGMT_RX_RING_SIZE;
        cvmx_write_csr(p->mix + MIX_IRING1, iring1.u64);

        memcpy(sa.sa_data, netdev->dev_addr, ETH_ALEN);
        octeon_mgmt_set_mac_address(netdev, &sa);

        octeon_mgmt_change_mtu(netdev, netdev->mtu);

        /* Enable the port HW. Packets are not allowed until
         * cvmx_mgmt_port_enable() is called.
         */
        mix_ctl.u64 = 0;
        mix_ctl.s.crc_strip = 1;    /* Strip the ending CRC */
        mix_ctl.s.en = 1;           /* Enable the port */
        mix_ctl.s.nbtarb = 0;       /* Arbitration mode */
        /* MII CB-request FIFO programmable high watermark */
        mix_ctl.s.mrq_hwm = 1;
#ifdef __LITTLE_ENDIAN
        mix_ctl.s.lendian = 1;
#endif
        cvmx_write_csr(p->mix + MIX_CTL, mix_ctl.u64);

        /* Read the PHY to find the mode of the interface. */
        if (octeon_mgmt_init_phy(netdev)) {
                dev_err(p->dev, "Cannot initialize PHY on MIX%d.\n", p->port);
                goto err_noirq;
        }

        /* Set the mode of the interface, RGMII/MII. */
        if (OCTEON_IS_MODEL(OCTEON_CN6XXX) && netdev->phydev) {
                union cvmx_agl_prtx_ctl agl_prtx_ctl;
                int rgmii_mode = (netdev->phydev->supported &
                                  (SUPPORTED_1000baseT_Half | SUPPORTED_1000baseT_Full)) != 0;

                agl_prtx_ctl.u64 = cvmx_read_csr(p->agl_prt_ctl);
                agl_prtx_ctl.s.mode = rgmii_mode ? 0 : 1;
                cvmx_write_csr(p->agl_prt_ctl,  agl_prtx_ctl.u64);

                /* MII clocks counts are based on the 125Mhz
                 * reference, which has an 8nS period. So our delays
                 * need to be multiplied by this factor.
                 */
#define NS_PER_PHY_CLK 8

                /* Take the DLL and clock tree out of reset */
                agl_prtx_ctl.u64 = cvmx_read_csr(p->agl_prt_ctl);
                agl_prtx_ctl.s.clkrst = 0;
                if (rgmii_mode) {
                        agl_prtx_ctl.s.dllrst = 0;
                        agl_prtx_ctl.s.clktx_byp = 0;
                }
                cvmx_write_csr(p->agl_prt_ctl,  agl_prtx_ctl.u64);
                cvmx_read_csr(p->agl_prt_ctl); /* Force write out before wait */

                /* Wait for the DLL to lock. External 125 MHz
                 * reference clock must be stable at this point.
                 */
                ndelay(256 * NS_PER_PHY_CLK);

                /* Enable the interface */
                agl_prtx_ctl.u64 = cvmx_read_csr(p->agl_prt_ctl);
                agl_prtx_ctl.s.enable = 1;
                cvmx_write_csr(p->agl_prt_ctl, agl_prtx_ctl.u64);

                /* Read the value back to force the previous write */
                agl_prtx_ctl.u64 = cvmx_read_csr(p->agl_prt_ctl);

                /* Enable the compensation controller */
                agl_prtx_ctl.s.comp = 1;
                agl_prtx_ctl.s.drv_byp = 0;
                cvmx_write_csr(p->agl_prt_ctl,  agl_prtx_ctl.u64);
                /* Force write out before wait. */
                cvmx_read_csr(p->agl_prt_ctl);

                /* For compensation state to lock. */
                ndelay(1040 * NS_PER_PHY_CLK);

                /* Default Interframe Gaps are too small.  Recommended
                 * workaround is.
                 *
                 * AGL_GMX_TX_IFG[IFG1]=14
                 * AGL_GMX_TX_IFG[IFG2]=10
                 */
                cvmx_write_csr(CVMX_AGL_GMX_TX_IFG, 0xae);
        }

        octeon_mgmt_rx_fill_ring(netdev);

        /* Clear statistics. */
        /* Clear on read. */
        cvmx_write_csr(p->agl + AGL_GMX_RX_STATS_CTL, 1);
        cvmx_write_csr(p->agl + AGL_GMX_RX_STATS_PKTS_DRP, 0);
        cvmx_write_csr(p->agl + AGL_GMX_RX_STATS_PKTS_BAD, 0);

        cvmx_write_csr(p->agl + AGL_GMX_TX_STATS_CTL, 1);
        cvmx_write_csr(p->agl + AGL_GMX_TX_STAT0, 0);
        cvmx_write_csr(p->agl + AGL_GMX_TX_STAT1, 0);

        /* Clear any pending interrupts */
        cvmx_write_csr(p->mix + MIX_ISR, cvmx_read_csr(p->mix + MIX_ISR));

        if (request_irq(p->irq, octeon_mgmt_interrupt, 0, netdev->name,
                        netdev)) {
                dev_err(p->dev, "request_irq(%d) failed.\n", p->irq);
                goto err_noirq;
        }

        /* Interrupt every single RX packet */
        mix_irhwm.u64 = 0;
        mix_irhwm.s.irhwm = 0;
        cvmx_write_csr(p->mix + MIX_IRHWM, mix_irhwm.u64);

        /* Interrupt when we have 1 or more packets to clean.  */
        mix_orhwm.u64 = 0;
        mix_orhwm.s.orhwm = 0;
        cvmx_write_csr(p->mix + MIX_ORHWM, mix_orhwm.u64);

        /* Enable receive and transmit interrupts */
        mix_intena.u64 = 0;
        mix_intena.s.ithena = 1;
        mix_intena.s.othena = 1;
        cvmx_write_csr(p->mix + MIX_INTENA, mix_intena.u64);

        /* Enable packet I/O. */

        rxx_frm_ctl.u64 = 0;
        rxx_frm_ctl.s.ptp_mode = p->has_rx_tstamp ? 1 : 0;
        rxx_frm_ctl.s.pre_align = 1;
        /* When set, disables the length check for non-min sized pkts
         * with padding in the client data.
         */
        rxx_frm_ctl.s.pad_len = 1;
        /* When set, disables the length check for VLAN pkts */
        rxx_frm_ctl.s.vlan_len = 1;
        /* When set, PREAMBLE checking is  less strict */
        rxx_frm_ctl.s.pre_free = 1;
        /* Control Pause Frames can match station SMAC */
        rxx_frm_ctl.s.ctl_smac = 0;
        /* Control Pause Frames can match globally assign Multicast address */
        rxx_frm_ctl.s.ctl_mcst = 1;
        /* Forward pause information to TX block */
        rxx_frm_ctl.s.ctl_bck = 1;
        /* Drop Control Pause Frames */
        rxx_frm_ctl.s.ctl_drp = 1;
        /* Strip off the preamble */
        rxx_frm_ctl.s.pre_strp = 1;
        /* This port is configured to send PREAMBLE+SFD to begin every
         * frame.  GMX checks that the PREAMBLE is sent correctly.
         */
        rxx_frm_ctl.s.pre_chk = 1;
        cvmx_write_csr(p->agl + AGL_GMX_RX_FRM_CTL, rxx_frm_ctl.u64);

        /* Configure the port duplex, speed and enables */
        octeon_mgmt_disable_link(p);
        if (netdev->phydev)
                octeon_mgmt_update_link(p);
        octeon_mgmt_enable_link(p);

        p->last_link = 0;
        p->last_speed = 0;
        /* PHY is not present in simulator. The carrier is enabled
         * while initializing the phy for simulator, leave it enabled.
         */
        if (netdev->phydev) {
                netif_carrier_off(netdev);
                phy_start_aneg(netdev->phydev);
        }

        netif_wake_queue(netdev);
        napi_enable(&p->napi);

        return 0;
err_noirq:
        octeon_mgmt_reset_hw(p);
        dma_unmap_single(p->dev, p->rx_ring_handle,
                         ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE),
                         DMA_BIDIRECTIONAL);
        kfree(p->rx_ring);
err_nomem:
        dma_unmap_single(p->dev, p->tx_ring_handle,
                         ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
                         DMA_BIDIRECTIONAL);
        kfree(p->tx_ring);
        return -ENOMEM;
}

static int octeon_mgmt_stop(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);

        napi_disable(&p->napi);
        netif_stop_queue(netdev);

        if (netdev->phydev)
                phy_disconnect(netdev->phydev);

        netif_carrier_off(netdev);

        octeon_mgmt_reset_hw(p);

        free_irq(p->irq, netdev);

        /* dma_unmap is a nop on Octeon, so just free everything.  */
        skb_queue_purge(&p->tx_list);
        skb_queue_purge(&p->rx_list);

        dma_unmap_single(p->dev, p->rx_ring_handle,
                         ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE),
                         DMA_BIDIRECTIONAL);
        kfree(p->rx_ring);

        dma_unmap_single(p->dev, p->tx_ring_handle,
                         ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
                         DMA_BIDIRECTIONAL);
        kfree(p->tx_ring);

        return 0;
}

static int octeon_mgmt_xmit(struct sk_buff *skb, struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);
        union mgmt_port_ring_entry re;
        unsigned long flags;
        int rv = NETDEV_TX_BUSY;

        re.d64 = 0;
        re.s.tstamp = ((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) != 0);
        re.s.len = skb->len;
        re.s.addr = dma_map_single(p->dev, skb->data,
                                   skb->len,
                                   DMA_TO_DEVICE);

        spin_lock_irqsave(&p->tx_list.lock, flags);

        if (unlikely(p->tx_current_fill >= ring_max_fill(OCTEON_MGMT_TX_RING_SIZE) - 1)) {
                spin_unlock_irqrestore(&p->tx_list.lock, flags);
                netif_stop_queue(netdev);
                spin_lock_irqsave(&p->tx_list.lock, flags);
        }

        if (unlikely(p->tx_current_fill >=
                     ring_max_fill(OCTEON_MGMT_TX_RING_SIZE))) {
                spin_unlock_irqrestore(&p->tx_list.lock, flags);
                dma_unmap_single(p->dev, re.s.addr, re.s.len,
                                 DMA_TO_DEVICE);
                goto out;
        }

        __skb_queue_tail(&p->tx_list, skb);

        /* Put it in the ring.  */
        p->tx_ring[p->tx_next] = re.d64;
        p->tx_next = (p->tx_next + 1) % OCTEON_MGMT_TX_RING_SIZE;
        p->tx_current_fill++;

        spin_unlock_irqrestore(&p->tx_list.lock, flags);

        dma_sync_single_for_device(p->dev, p->tx_ring_handle,
                                   ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
                                   DMA_BIDIRECTIONAL);

        netdev->stats.tx_packets++;
        netdev->stats.tx_bytes += skb->len;

        /* Ring the bell.  */
        cvmx_write_csr(p->mix + MIX_ORING2, 1);

        netif_trans_update(netdev);
        rv = NETDEV_TX_OK;
out:
        octeon_mgmt_update_tx_stats(netdev);
        return rv;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void octeon_mgmt_poll_controller(struct net_device *netdev)
{
        struct octeon_mgmt *p = netdev_priv(netdev);

        octeon_mgmt_receive_packets(p, 16);
        octeon_mgmt_update_rx_stats(netdev);
}
#endif

static void octeon_mgmt_get_drvinfo(struct net_device *netdev,
                                    struct ethtool_drvinfo *info)
{
        strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
        strlcpy(info->version, DRV_VERSION, sizeof(info->version));
        strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
        strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
}

static int octeon_mgmt_nway_reset(struct net_device *dev)
{
        if (!capable(CAP_NET_ADMIN))
                return -EPERM;

        if (dev->phydev)
                return phy_start_aneg(dev->phydev);

        return -EOPNOTSUPP;
}

static const struct ethtool_ops octeon_mgmt_ethtool_ops = {
        .get_drvinfo = octeon_mgmt_get_drvinfo,
        .nway_reset = octeon_mgmt_nway_reset,
        .get_link = ethtool_op_get_link,
        .get_link_ksettings = phy_ethtool_get_link_ksettings,
        .set_link_ksettings = phy_ethtool_set_link_ksettings,
};

static const struct net_device_ops octeon_mgmt_ops = {
        .ndo_open =                     octeon_mgmt_open,
        .ndo_stop =                     octeon_mgmt_stop,
        .ndo_start_xmit =               octeon_mgmt_xmit,
        .ndo_set_rx_mode =              octeon_mgmt_set_rx_filtering,
        .ndo_set_mac_address =          octeon_mgmt_set_mac_address,
        .ndo_do_ioctl =                 octeon_mgmt_ioctl,
        .ndo_change_mtu =               octeon_mgmt_change_mtu,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller =          octeon_mgmt_poll_controller,
#endif
};

static int octeon_mgmt_probe(struct platform_device *pdev)
{
        struct net_device *netdev;
        struct octeon_mgmt *p;
        const __be32 *data;
        const u8 *mac;
        struct resource *res_mix;
        struct resource *res_agl;
        struct resource *res_agl_prt_ctl;
        int len;
        int result;

        netdev = alloc_etherdev(sizeof(struct octeon_mgmt));
        if (netdev == NULL)
                return -ENOMEM;

        SET_NETDEV_DEV(netdev, &pdev->dev);

        platform_set_drvdata(pdev, netdev);
        p = netdev_priv(netdev);
        netif_napi_add(netdev, &p->napi, octeon_mgmt_napi_poll,
                       OCTEON_MGMT_NAPI_WEIGHT);

        p->netdev = netdev;
        p->dev = &pdev->dev;
        p->has_rx_tstamp = false;

        data = of_get_property(pdev->dev.of_node, "cell-index", &len);
        if (data && len == sizeof(*data)) {
                p->port = be32_to_cpup(data);
        } else {
                dev_err(&pdev->dev, "no 'cell-index' property\n");
                result = -ENXIO;
                goto err;
        }

        snprintf(netdev->name, IFNAMSIZ, "mgmt%d", p->port);

        result = platform_get_irq(pdev, 0);
        if (result < 0)
                goto err;

        p->irq = result;

        res_mix = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res_mix == NULL) {
                dev_err(&pdev->dev, "no 'reg' resource\n");
                result = -ENXIO;
                goto err;
        }

        res_agl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        if (res_agl == NULL) {
                dev_err(&pdev->dev, "no 'reg' resource\n");
                result = -ENXIO;
                goto err;
        }

        res_agl_prt_ctl = platform_get_resource(pdev, IORESOURCE_MEM, 3);
        if (res_agl_prt_ctl == NULL) {
                dev_err(&pdev->dev, "no 'reg' resource\n");
                result = -ENXIO;
                goto err;
        }

        p->mix_phys = res_mix->start;
        p->mix_size = resource_size(res_mix);
        p->agl_phys = res_agl->start;
        p->agl_size = resource_size(res_agl);
        p->agl_prt_ctl_phys = res_agl_prt_ctl->start;
        p->agl_prt_ctl_size = resource_size(res_agl_prt_ctl);


        if (!devm_request_mem_region(&pdev->dev, p->mix_phys, p->mix_size,
                                     res_mix->name)) {
                dev_err(&pdev->dev, "request_mem_region (%s) failed\n",
                        res_mix->name);
                result = -ENXIO;
                goto err;
        }

        if (!devm_request_mem_region(&pdev->dev, p->agl_phys, p->agl_size,
                                     res_agl->name)) {
                result = -ENXIO;
                dev_err(&pdev->dev, "request_mem_region (%s) failed\n",
                        res_agl->name);
                goto err;
        }

        if (!devm_request_mem_region(&pdev->dev, p->agl_prt_ctl_phys,
                                     p->agl_prt_ctl_size, res_agl_prt_ctl->name)) {
                result = -ENXIO;
                dev_err(&pdev->dev, "request_mem_region (%s) failed\n",
                        res_agl_prt_ctl->name);
                goto err;
        }

        p->mix = (u64)devm_ioremap(&pdev->dev, p->mix_phys, p->mix_size);
        p->agl = (u64)devm_ioremap(&pdev->dev, p->agl_phys, p->agl_size);
        p->agl_prt_ctl = (u64)devm_ioremap(&pdev->dev, p->agl_prt_ctl_phys,
                                           p->agl_prt_ctl_size);
        spin_lock_init(&p->lock);

        skb_queue_head_init(&p->tx_list);
        skb_queue_head_init(&p->rx_list);
        tasklet_init(&p->tx_clean_tasklet,
                     octeon_mgmt_clean_tx_tasklet, (unsigned long)p);

        netdev->priv_flags |= IFF_UNICAST_FLT;

        netdev->netdev_ops = &octeon_mgmt_ops;
        netdev->ethtool_ops = &octeon_mgmt_ethtool_ops;

        mac = of_get_mac_address(pdev->dev.of_node);

        if (mac)
                memcpy(netdev->dev_addr, mac, ETH_ALEN);
        else
                eth_hw_addr_random(netdev);

        p->phy_np = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);

        result = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
        if (result)
                goto err;

        netif_carrier_off(netdev);
        result = register_netdev(netdev);
        if (result)
                goto err;

        dev_info(&pdev->dev, "Version " DRV_VERSION "\n");
        return 0;

err:
        of_node_put(p->phy_np);
        free_netdev(netdev);
        return result;
}

static int octeon_mgmt_remove(struct platform_device *pdev)
{
        struct net_device *netdev = platform_get_drvdata(pdev);
        struct octeon_mgmt *p = netdev_priv(netdev);

        unregister_netdev(netdev);
        of_node_put(p->phy_np);
        free_netdev(netdev);
        return 0;
}

static const struct of_device_id octeon_mgmt_match[] = {
        {
                .compatible = "cavium,octeon-5750-mix",
        },
        {},
};
MODULE_DEVICE_TABLE(of, octeon_mgmt_match);

static struct platform_driver octeon_mgmt_driver = {
        .driver = {
                .name           = "octeon_mgmt",
                .of_match_table = octeon_mgmt_match,
        },
        .probe          = octeon_mgmt_probe,
        .remove         = octeon_mgmt_remove,
};

extern void octeon_mdiobus_force_mod_depencency(void);

static int __init octeon_mgmt_mod_init(void)
{
        /* Force our mdiobus driver module to be loaded first. */
        octeon_mdiobus_force_mod_depencency();
        return platform_driver_register(&octeon_mgmt_driver);
}

static void __exit octeon_mgmt_mod_exit(void)
{
        platform_driver_unregister(&octeon_mgmt_driver);
}

module_init(octeon_mgmt_mod_init);
module_exit(octeon_mgmt_mod_exit);

MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);