virtio_net: Fix skb->csum_start computation

[linux-2.6] / drivers / net / mv643xx_eth.c

/*
 * Driver for Marvell Discovery (MV643XX) and Marvell Orion ethernet ports
 * Copyright (C) 2002 Matthew Dharm <mdharm@momenco.com>
 *
 * Based on the 64360 driver from:
 * Copyright (C) 2002 Rabeeh Khoury <rabeeh@galileo.co.il>
 *                    Rabeeh Khoury <rabeeh@marvell.com>
 *
 * Copyright (C) 2003 PMC-Sierra, Inc.,
 *      written by Manish Lachwani
 *
 * Copyright (C) 2003 Ralf Baechle <ralf@linux-mips.org>
 *
 * Copyright (C) 2004-2006 MontaVista Software, Inc.
 *                         Dale Farnsworth <dale@farnsworth.org>
 *
 * Copyright (C) 2004 Steven J. Hill <sjhill1@rockwellcollins.com>
 *                                   <sjhill@realitydiluted.com>
 *
 * Copyright (C) 2007-2008 Marvell Semiconductor
 *                         Lennert Buytenhek <buytenh@marvell.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/etherdevice.h>

#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/ethtool.h>
#include <linux/platform_device.h>

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/mii.h>

#include <linux/mv643xx_eth.h>

#include <asm/io.h>
#include <asm/types.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/delay.h>
#include <asm/dma-mapping.h>

#define MV643XX_CHECKSUM_OFFLOAD_TX
#define MV643XX_NAPI
#define MV643XX_TX_FAST_REFILL
#undef  MV643XX_COAL

#define MV643XX_TX_COAL 100
#ifdef MV643XX_COAL
#define MV643XX_RX_COAL 100
#endif

#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
#define MAX_DESCS_PER_SKB       (MAX_SKB_FRAGS + 1)
#else
#define MAX_DESCS_PER_SKB       1
#endif

#define ETH_VLAN_HLEN           4
#define ETH_FCS_LEN             4
#define ETH_HW_IP_ALIGN         2               /* hw aligns IP header */
#define ETH_WRAPPER_LEN         (ETH_HW_IP_ALIGN + ETH_HLEN + \
                                        ETH_VLAN_HLEN + ETH_FCS_LEN)
#define ETH_RX_SKB_SIZE         (dev->mtu + ETH_WRAPPER_LEN + \
                                        dma_get_cache_alignment())

/*
 * Registers shared between all ports.
 */
#define PHY_ADDR_REG                            0x0000
#define SMI_REG                                 0x0004
#define WINDOW_BASE(i)                          (0x0200 + ((i) << 3))
#define WINDOW_SIZE(i)                          (0x0204 + ((i) << 3))
#define WINDOW_REMAP_HIGH(i)                    (0x0280 + ((i) << 2))
#define WINDOW_BAR_ENABLE                       0x0290
#define WINDOW_PROTECT(i)                       (0x0294 + ((i) << 4))

/*
 * Per-port registers.
 */
#define PORT_CONFIG_REG(p)                              (0x0400 + ((p) << 10))
#define PORT_CONFIG_EXTEND_REG(p)                       (0x0404 + ((p) << 10))
#define MAC_ADDR_LOW(p)                                 (0x0414 + ((p) << 10))
#define MAC_ADDR_HIGH(p)                                (0x0418 + ((p) << 10))
#define SDMA_CONFIG_REG(p)                              (0x041c + ((p) << 10))
#define PORT_SERIAL_CONTROL_REG(p)                      (0x043c + ((p) << 10))
#define PORT_STATUS_REG(p)                              (0x0444 + ((p) << 10))
#define TRANSMIT_QUEUE_COMMAND_REG(p)                   (0x0448 + ((p) << 10))
#define MAXIMUM_TRANSMIT_UNIT(p)                        (0x0458 + ((p) << 10))
#define INTERRUPT_CAUSE_REG(p)                          (0x0460 + ((p) << 10))
#define INTERRUPT_CAUSE_EXTEND_REG(p)                   (0x0464 + ((p) << 10))
#define INTERRUPT_MASK_REG(p)                           (0x0468 + ((p) << 10))
#define INTERRUPT_EXTEND_MASK_REG(p)                    (0x046c + ((p) << 10))
#define TX_FIFO_URGENT_THRESHOLD_REG(p)                 (0x0474 + ((p) << 10))
#define RX_CURRENT_QUEUE_DESC_PTR_0(p)                  (0x060c + ((p) << 10))
#define RECEIVE_QUEUE_COMMAND_REG(p)                    (0x0680 + ((p) << 10))
#define TX_CURRENT_QUEUE_DESC_PTR_0(p)                  (0x06c0 + ((p) << 10))
#define MIB_COUNTERS_BASE(p)                            (0x1000 + ((p) << 7))
#define DA_FILTER_SPECIAL_MULTICAST_TABLE_BASE(p)       (0x1400 + ((p) << 10))
#define DA_FILTER_OTHER_MULTICAST_TABLE_BASE(p)         (0x1500 + ((p) << 10))
#define DA_FILTER_UNICAST_TABLE_BASE(p)                 (0x1600 + ((p) << 10))

/* These macros describe Ethernet Port configuration reg (Px_cR) bits */
#define UNICAST_NORMAL_MODE             (0 << 0)
#define UNICAST_PROMISCUOUS_MODE        (1 << 0)
#define DEFAULT_RX_QUEUE(queue)         ((queue) << 1)
#define DEFAULT_RX_ARP_QUEUE(queue)     ((queue) << 4)
#define RECEIVE_BC_IF_NOT_IP_OR_ARP     (0 << 7)
#define REJECT_BC_IF_NOT_IP_OR_ARP      (1 << 7)
#define RECEIVE_BC_IF_IP                (0 << 8)
#define REJECT_BC_IF_IP                 (1 << 8)
#define RECEIVE_BC_IF_ARP               (0 << 9)
#define REJECT_BC_IF_ARP                (1 << 9)
#define TX_AM_NO_UPDATE_ERROR_SUMMARY   (1 << 12)
#define CAPTURE_TCP_FRAMES_DIS          (0 << 14)
#define CAPTURE_TCP_FRAMES_EN           (1 << 14)
#define CAPTURE_UDP_FRAMES_DIS          (0 << 15)
#define CAPTURE_UDP_FRAMES_EN           (1 << 15)
#define DEFAULT_RX_TCP_QUEUE(queue)     ((queue) << 16)
#define DEFAULT_RX_UDP_QUEUE(queue)     ((queue) << 19)
#define DEFAULT_RX_BPDU_QUEUE(queue)    ((queue) << 22)

#define PORT_CONFIG_DEFAULT_VALUE                       \
                UNICAST_NORMAL_MODE             |       \
                DEFAULT_RX_QUEUE(0)             |       \
                DEFAULT_RX_ARP_QUEUE(0)         |       \
                RECEIVE_BC_IF_NOT_IP_OR_ARP     |       \
                RECEIVE_BC_IF_IP                |       \
                RECEIVE_BC_IF_ARP               |       \
                CAPTURE_TCP_FRAMES_DIS          |       \
                CAPTURE_UDP_FRAMES_DIS          |       \
                DEFAULT_RX_TCP_QUEUE(0)         |       \
                DEFAULT_RX_UDP_QUEUE(0)         |       \
                DEFAULT_RX_BPDU_QUEUE(0)

/* These macros describe Ethernet Port configuration extend reg (Px_cXR) bits*/
#define CLASSIFY_EN                             (1 << 0)
#define SPAN_BPDU_PACKETS_AS_NORMAL             (0 << 1)
#define SPAN_BPDU_PACKETS_TO_RX_QUEUE_7         (1 << 1)
#define PARTITION_DISABLE                       (0 << 2)
#define PARTITION_ENABLE                        (1 << 2)

#define PORT_CONFIG_EXTEND_DEFAULT_VALUE                \
                SPAN_BPDU_PACKETS_AS_NORMAL     |       \
                PARTITION_DISABLE

/* These macros describe Ethernet Port Sdma configuration reg (SDCR) bits */
#define RIFB                            (1 << 0)
#define RX_BURST_SIZE_1_64BIT           (0 << 1)
#define RX_BURST_SIZE_2_64BIT           (1 << 1)
#define RX_BURST_SIZE_4_64BIT           (2 << 1)
#define RX_BURST_SIZE_8_64BIT           (3 << 1)
#define RX_BURST_SIZE_16_64BIT          (4 << 1)
#define BLM_RX_NO_SWAP                  (1 << 4)
#define BLM_RX_BYTE_SWAP                (0 << 4)
#define BLM_TX_NO_SWAP                  (1 << 5)
#define BLM_TX_BYTE_SWAP                (0 << 5)
#define DESCRIPTORS_BYTE_SWAP           (1 << 6)
#define DESCRIPTORS_NO_SWAP             (0 << 6)
#define IPG_INT_RX(value)               (((value) & 0x3fff) << 8)
#define TX_BURST_SIZE_1_64BIT           (0 << 22)
#define TX_BURST_SIZE_2_64BIT           (1 << 22)
#define TX_BURST_SIZE_4_64BIT           (2 << 22)
#define TX_BURST_SIZE_8_64BIT           (3 << 22)
#define TX_BURST_SIZE_16_64BIT          (4 << 22)

#if defined(__BIG_ENDIAN)
#define PORT_SDMA_CONFIG_DEFAULT_VALUE          \
                RX_BURST_SIZE_4_64BIT   |       \
                IPG_INT_RX(0)           |       \
                TX_BURST_SIZE_4_64BIT
#elif defined(__LITTLE_ENDIAN)
#define PORT_SDMA_CONFIG_DEFAULT_VALUE          \
                RX_BURST_SIZE_4_64BIT   |       \
                BLM_RX_NO_SWAP          |       \
                BLM_TX_NO_SWAP          |       \
                IPG_INT_RX(0)           |       \
                TX_BURST_SIZE_4_64BIT
#else
#error One of __BIG_ENDIAN or __LITTLE_ENDIAN must be defined
#endif

/* These macros describe Ethernet Port serial control reg (PSCR) bits */
#define SERIAL_PORT_DISABLE                     (0 << 0)
#define SERIAL_PORT_ENABLE                      (1 << 0)
#define DO_NOT_FORCE_LINK_PASS                  (0 << 1)
#define FORCE_LINK_PASS                         (1 << 1)
#define ENABLE_AUTO_NEG_FOR_DUPLX               (0 << 2)
#define DISABLE_AUTO_NEG_FOR_DUPLX              (1 << 2)
#define ENABLE_AUTO_NEG_FOR_FLOW_CTRL           (0 << 3)
#define DISABLE_AUTO_NEG_FOR_FLOW_CTRL          (1 << 3)
#define ADV_NO_FLOW_CTRL                        (0 << 4)
#define ADV_SYMMETRIC_FLOW_CTRL                 (1 << 4)
#define FORCE_FC_MODE_NO_PAUSE_DIS_TX           (0 << 5)
#define FORCE_FC_MODE_TX_PAUSE_DIS              (1 << 5)
#define FORCE_BP_MODE_NO_JAM                    (0 << 7)
#define FORCE_BP_MODE_JAM_TX                    (1 << 7)
#define FORCE_BP_MODE_JAM_TX_ON_RX_ERR          (2 << 7)
#define SERIAL_PORT_CONTROL_RESERVED            (1 << 9)
#define FORCE_LINK_FAIL                         (0 << 10)
#define DO_NOT_FORCE_LINK_FAIL                  (1 << 10)
#define RETRANSMIT_16_ATTEMPTS                  (0 << 11)
#define RETRANSMIT_FOREVER                      (1 << 11)
#define ENABLE_AUTO_NEG_SPEED_GMII              (0 << 13)
#define DISABLE_AUTO_NEG_SPEED_GMII             (1 << 13)
#define DTE_ADV_0                               (0 << 14)
#define DTE_ADV_1                               (1 << 14)
#define DISABLE_AUTO_NEG_BYPASS                 (0 << 15)
#define ENABLE_AUTO_NEG_BYPASS                  (1 << 15)
#define AUTO_NEG_NO_CHANGE                      (0 << 16)
#define RESTART_AUTO_NEG                        (1 << 16)
#define MAX_RX_PACKET_1518BYTE                  (0 << 17)
#define MAX_RX_PACKET_1522BYTE                  (1 << 17)
#define MAX_RX_PACKET_1552BYTE                  (2 << 17)
#define MAX_RX_PACKET_9022BYTE                  (3 << 17)
#define MAX_RX_PACKET_9192BYTE                  (4 << 17)
#define MAX_RX_PACKET_9700BYTE                  (5 << 17)
#define MAX_RX_PACKET_MASK                      (7 << 17)
#define CLR_EXT_LOOPBACK                        (0 << 20)
#define SET_EXT_LOOPBACK                        (1 << 20)
#define SET_HALF_DUPLEX_MODE                    (0 << 21)
#define SET_FULL_DUPLEX_MODE                    (1 << 21)
#define DISABLE_FLOW_CTRL_TX_RX_IN_FULL_DUPLEX  (0 << 22)
#define ENABLE_FLOW_CTRL_TX_RX_IN_FULL_DUPLEX   (1 << 22)
#define SET_GMII_SPEED_TO_10_100                (0 << 23)
#define SET_GMII_SPEED_TO_1000                  (1 << 23)
#define SET_MII_SPEED_TO_10                     (0 << 24)
#define SET_MII_SPEED_TO_100                    (1 << 24)

#define PORT_SERIAL_CONTROL_DEFAULT_VALUE               \
                DO_NOT_FORCE_LINK_PASS          |       \
                ENABLE_AUTO_NEG_FOR_DUPLX       |       \
                DISABLE_AUTO_NEG_FOR_FLOW_CTRL  |       \
                ADV_SYMMETRIC_FLOW_CTRL         |       \
                FORCE_FC_MODE_NO_PAUSE_DIS_TX   |       \
                FORCE_BP_MODE_NO_JAM            |       \
                (1 << 9) /* reserved */         |       \
                DO_NOT_FORCE_LINK_FAIL          |       \
                RETRANSMIT_16_ATTEMPTS          |       \
                ENABLE_AUTO_NEG_SPEED_GMII      |       \
                DTE_ADV_0                       |       \
                DISABLE_AUTO_NEG_BYPASS         |       \
                AUTO_NEG_NO_CHANGE              |       \
                MAX_RX_PACKET_9700BYTE          |       \
                CLR_EXT_LOOPBACK                |       \
                SET_FULL_DUPLEX_MODE            |       \
                ENABLE_FLOW_CTRL_TX_RX_IN_FULL_DUPLEX

/* These macros describe Ethernet Serial Status reg (PSR) bits */
#define PORT_STATUS_MODE_10_BIT         (1 << 0)
#define PORT_STATUS_LINK_UP             (1 << 1)
#define PORT_STATUS_FULL_DUPLEX         (1 << 2)
#define PORT_STATUS_FLOW_CONTROL        (1 << 3)
#define PORT_STATUS_GMII_1000           (1 << 4)
#define PORT_STATUS_MII_100             (1 << 5)
/* PSR bit 6 is undocumented */
#define PORT_STATUS_TX_IN_PROGRESS      (1 << 7)
#define PORT_STATUS_AUTONEG_BYPASSED    (1 << 8)
#define PORT_STATUS_PARTITION           (1 << 9)
#define PORT_STATUS_TX_FIFO_EMPTY       (1 << 10)
/* PSR bits 11-31 are reserved */

#define PORT_DEFAULT_TRANSMIT_QUEUE_SIZE        800
#define PORT_DEFAULT_RECEIVE_QUEUE_SIZE         400

#define DESC_SIZE                               64

#define ETH_RX_QUEUES_ENABLED   (1 << 0)        /* use only Q0 for receive */
#define ETH_TX_QUEUES_ENABLED   (1 << 0)        /* use only Q0 for transmit */

#define ETH_INT_CAUSE_RX_DONE   (ETH_RX_QUEUES_ENABLED << 2)
#define ETH_INT_CAUSE_RX_ERROR  (ETH_RX_QUEUES_ENABLED << 9)
#define ETH_INT_CAUSE_RX        (ETH_INT_CAUSE_RX_DONE | ETH_INT_CAUSE_RX_ERROR)
#define ETH_INT_CAUSE_EXT       0x00000002
#define ETH_INT_UNMASK_ALL      (ETH_INT_CAUSE_RX | ETH_INT_CAUSE_EXT)

#define ETH_INT_CAUSE_TX_DONE   (ETH_TX_QUEUES_ENABLED << 0)
#define ETH_INT_CAUSE_TX_ERROR  (ETH_TX_QUEUES_ENABLED << 8)
#define ETH_INT_CAUSE_TX        (ETH_INT_CAUSE_TX_DONE | ETH_INT_CAUSE_TX_ERROR)
#define ETH_INT_CAUSE_PHY       0x00010000
#define ETH_INT_CAUSE_STATE     0x00100000
#define ETH_INT_UNMASK_ALL_EXT  (ETH_INT_CAUSE_TX | ETH_INT_CAUSE_PHY | \
                                        ETH_INT_CAUSE_STATE)

#define ETH_INT_MASK_ALL        0x00000000
#define ETH_INT_MASK_ALL_EXT    0x00000000

#define PHY_WAIT_ITERATIONS     1000    /* 1000 iterations * 10uS = 10mS max */
#define PHY_WAIT_MICRO_SECONDS  10

/* Buffer offset from buffer pointer */
#define RX_BUF_OFFSET                           0x2

/* Gigabit Ethernet Unit Global Registers */

/* MIB Counters register definitions */
#define ETH_MIB_GOOD_OCTETS_RECEIVED_LOW        0x0
#define ETH_MIB_GOOD_OCTETS_RECEIVED_HIGH       0x4
#define ETH_MIB_BAD_OCTETS_RECEIVED             0x8
#define ETH_MIB_INTERNAL_MAC_TRANSMIT_ERR       0xc
#define ETH_MIB_GOOD_FRAMES_RECEIVED            0x10
#define ETH_MIB_BAD_FRAMES_RECEIVED             0x14
#define ETH_MIB_BROADCAST_FRAMES_RECEIVED       0x18
#define ETH_MIB_MULTICAST_FRAMES_RECEIVED       0x1c
#define ETH_MIB_FRAMES_64_OCTETS                0x20
#define ETH_MIB_FRAMES_65_TO_127_OCTETS         0x24
#define ETH_MIB_FRAMES_128_TO_255_OCTETS        0x28
#define ETH_MIB_FRAMES_256_TO_511_OCTETS        0x2c
#define ETH_MIB_FRAMES_512_TO_1023_OCTETS       0x30
#define ETH_MIB_FRAMES_1024_TO_MAX_OCTETS       0x34
#define ETH_MIB_GOOD_OCTETS_SENT_LOW            0x38
#define ETH_MIB_GOOD_OCTETS_SENT_HIGH           0x3c
#define ETH_MIB_GOOD_FRAMES_SENT                0x40
#define ETH_MIB_EXCESSIVE_COLLISION             0x44
#define ETH_MIB_MULTICAST_FRAMES_SENT           0x48
#define ETH_MIB_BROADCAST_FRAMES_SENT           0x4c
#define ETH_MIB_UNREC_MAC_CONTROL_RECEIVED      0x50
#define ETH_MIB_FC_SENT                         0x54
#define ETH_MIB_GOOD_FC_RECEIVED                0x58
#define ETH_MIB_BAD_FC_RECEIVED                 0x5c
#define ETH_MIB_UNDERSIZE_RECEIVED              0x60
#define ETH_MIB_FRAGMENTS_RECEIVED              0x64
#define ETH_MIB_OVERSIZE_RECEIVED               0x68
#define ETH_MIB_JABBER_RECEIVED                 0x6c
#define ETH_MIB_MAC_RECEIVE_ERROR               0x70
#define ETH_MIB_BAD_CRC_EVENT                   0x74
#define ETH_MIB_COLLISION                       0x78
#define ETH_MIB_LATE_COLLISION                  0x7c

/* Port serial status reg (PSR) */
#define ETH_INTERFACE_PCM                       0x00000001
#define ETH_LINK_IS_UP                          0x00000002
#define ETH_PORT_AT_FULL_DUPLEX                 0x00000004
#define ETH_RX_FLOW_CTRL_ENABLED                0x00000008
#define ETH_GMII_SPEED_1000                     0x00000010
#define ETH_MII_SPEED_100                       0x00000020
#define ETH_TX_IN_PROGRESS                      0x00000080
#define ETH_BYPASS_ACTIVE                       0x00000100
#define ETH_PORT_AT_PARTITION_STATE             0x00000200
#define ETH_PORT_TX_FIFO_EMPTY                  0x00000400

/* SMI reg */
#define ETH_SMI_BUSY            0x10000000      /* 0 - Write, 1 - Read  */
#define ETH_SMI_READ_VALID      0x08000000      /* 0 - Write, 1 - Read  */
#define ETH_SMI_OPCODE_WRITE    0               /* Completion of Read   */
#define ETH_SMI_OPCODE_READ     0x04000000      /* Operation is in progress */

/* Interrupt Cause Register Bit Definitions */

/* SDMA command status fields macros */

/* Tx & Rx descriptors status */
#define ETH_ERROR_SUMMARY                       0x00000001

/* Tx & Rx descriptors command */
#define ETH_BUFFER_OWNED_BY_DMA                 0x80000000

/* Tx descriptors status */
#define ETH_LC_ERROR                            0
#define ETH_UR_ERROR                            0x00000002
#define ETH_RL_ERROR                            0x00000004
#define ETH_LLC_SNAP_FORMAT                     0x00000200

/* Rx descriptors status */
#define ETH_OVERRUN_ERROR                       0x00000002
#define ETH_MAX_FRAME_LENGTH_ERROR              0x00000004
#define ETH_RESOURCE_ERROR                      0x00000006
#define ETH_VLAN_TAGGED                         0x00080000
#define ETH_BPDU_FRAME                          0x00100000
#define ETH_UDP_FRAME_OVER_IP_V_4               0x00200000
#define ETH_OTHER_FRAME_TYPE                    0x00400000
#define ETH_LAYER_2_IS_ETH_V_2                  0x00800000
#define ETH_FRAME_TYPE_IP_V_4                   0x01000000
#define ETH_FRAME_HEADER_OK                     0x02000000
#define ETH_RX_LAST_DESC                        0x04000000
#define ETH_RX_FIRST_DESC                       0x08000000
#define ETH_UNKNOWN_DESTINATION_ADDR            0x10000000
#define ETH_RX_ENABLE_INTERRUPT                 0x20000000
#define ETH_LAYER_4_CHECKSUM_OK                 0x40000000

/* Rx descriptors byte count */
#define ETH_FRAME_FRAGMENTED                    0x00000004

/* Tx descriptors command */
#define ETH_LAYER_4_CHECKSUM_FIRST_DESC         0x00000400
#define ETH_FRAME_SET_TO_VLAN                   0x00008000
#define ETH_UDP_FRAME                           0x00010000
#define ETH_GEN_TCP_UDP_CHECKSUM                0x00020000
#define ETH_GEN_IP_V_4_CHECKSUM                 0x00040000
#define ETH_ZERO_PADDING                        0x00080000
#define ETH_TX_LAST_DESC                        0x00100000
#define ETH_TX_FIRST_DESC                       0x00200000
#define ETH_GEN_CRC                             0x00400000
#define ETH_TX_ENABLE_INTERRUPT                 0x00800000
#define ETH_AUTO_MODE                           0x40000000

#define ETH_TX_IHL_SHIFT                        11

/* typedefs */

typedef enum _eth_func_ret_status {
        ETH_OK,                 /* Returned as expected.                */
        ETH_ERROR,              /* Fundamental error.                   */
        ETH_RETRY,              /* Could not process request. Try later.*/
        ETH_END_OF_JOB,         /* Ring has nothing to process.         */
        ETH_QUEUE_FULL,         /* Ring resource error.                 */
        ETH_QUEUE_LAST_RESOURCE /* Ring resources about to exhaust.     */
} ETH_FUNC_RET_STATUS;

/* These are for big-endian machines.  Little endian needs different
 * definitions.
 */
#if defined(__BIG_ENDIAN)
struct eth_rx_desc {
        u16 byte_cnt;           /* Descriptor buffer byte count         */
        u16 buf_size;           /* Buffer size                          */
        u32 cmd_sts;            /* Descriptor command status            */
        u32 next_desc_ptr;      /* Next descriptor pointer              */
        u32 buf_ptr;            /* Descriptor buffer pointer            */
};

struct eth_tx_desc {
        u16 byte_cnt;           /* buffer byte count                    */
        u16 l4i_chk;            /* CPU provided TCP checksum            */
        u32 cmd_sts;            /* Command/status field                 */
        u32 next_desc_ptr;      /* Pointer to next descriptor           */
        u32 buf_ptr;            /* pointer to buffer for this descriptor*/
};
#elif defined(__LITTLE_ENDIAN)
struct eth_rx_desc {
        u32 cmd_sts;            /* Descriptor command status            */
        u16 buf_size;           /* Buffer size                          */
        u16 byte_cnt;           /* Descriptor buffer byte count         */
        u32 buf_ptr;            /* Descriptor buffer pointer            */
        u32 next_desc_ptr;      /* Next descriptor pointer              */
};

struct eth_tx_desc {
        u32 cmd_sts;            /* Command/status field                 */
        u16 l4i_chk;            /* CPU provided TCP checksum            */
        u16 byte_cnt;           /* buffer byte count                    */
        u32 buf_ptr;            /* pointer to buffer for this descriptor*/
        u32 next_desc_ptr;      /* Pointer to next descriptor           */
};
#else
#error One of __BIG_ENDIAN or __LITTLE_ENDIAN must be defined
#endif

/* Unified struct for Rx and Tx operations. The user is not required to */
/* be familier with neither Tx nor Rx descriptors.                      */
struct pkt_info {
        unsigned short byte_cnt;        /* Descriptor buffer byte count */
        unsigned short l4i_chk;         /* Tx CPU provided TCP Checksum */
        unsigned int cmd_sts;           /* Descriptor command status    */
        dma_addr_t buf_ptr;             /* Descriptor buffer pointer    */
        struct sk_buff *return_info;    /* User resource return information */
};

/* Ethernet port specific information */
struct mv643xx_mib_counters {
        u64 good_octets_received;
        u32 bad_octets_received;
        u32 internal_mac_transmit_err;
        u32 good_frames_received;
        u32 bad_frames_received;
        u32 broadcast_frames_received;
        u32 multicast_frames_received;
        u32 frames_64_octets;
        u32 frames_65_to_127_octets;
        u32 frames_128_to_255_octets;
        u32 frames_256_to_511_octets;
        u32 frames_512_to_1023_octets;
        u32 frames_1024_to_max_octets;
        u64 good_octets_sent;
        u32 good_frames_sent;
        u32 excessive_collision;
        u32 multicast_frames_sent;
        u32 broadcast_frames_sent;
        u32 unrec_mac_control_received;
        u32 fc_sent;
        u32 good_fc_received;
        u32 bad_fc_received;
        u32 undersize_received;
        u32 fragments_received;
        u32 oversize_received;
        u32 jabber_received;
        u32 mac_receive_error;
        u32 bad_crc_event;
        u32 collision;
        u32 late_collision;
};

struct mv643xx_shared_private {
        void __iomem *eth_base;

        /* used to protect SMI_REG, which is shared across ports */
        spinlock_t phy_lock;

        u32 win_protect;

        unsigned int t_clk;
};

struct mv643xx_private {
        struct mv643xx_shared_private *shared;
        int port_num;                   /* User Ethernet port number    */

        struct mv643xx_shared_private *shared_smi;

        u32 rx_sram_addr;               /* Base address of rx sram area */
        u32 rx_sram_size;               /* Size of rx sram area         */
        u32 tx_sram_addr;               /* Base address of tx sram area */
        u32 tx_sram_size;               /* Size of tx sram area         */

        int rx_resource_err;            /* Rx ring resource error flag */

        /* Tx/Rx rings managment indexes fields. For driver use */

        /* Next available and first returning Rx resource */
        int rx_curr_desc_q, rx_used_desc_q;

        /* Next available and first returning Tx resource */
        int tx_curr_desc_q, tx_used_desc_q;

#ifdef MV643XX_TX_FAST_REFILL
        u32 tx_clean_threshold;
#endif

        struct eth_rx_desc *p_rx_desc_area;
        dma_addr_t rx_desc_dma;
        int rx_desc_area_size;
        struct sk_buff **rx_skb;

        struct eth_tx_desc *p_tx_desc_area;
        dma_addr_t tx_desc_dma;
        int tx_desc_area_size;
        struct sk_buff **tx_skb;

        struct work_struct tx_timeout_task;

        struct net_device *dev;
        struct napi_struct napi;
        struct net_device_stats stats;
        struct mv643xx_mib_counters mib_counters;
        spinlock_t lock;
        /* Size of Tx Ring per queue */
        int tx_ring_size;
        /* Number of tx descriptors in use */
        int tx_desc_count;
        /* Size of Rx Ring per queue */
        int rx_ring_size;
        /* Number of rx descriptors in use */
        int rx_desc_count;

        /*
         * Used in case RX Ring is empty, which can be caused when
         * system does not have resources (skb's)
         */
        struct timer_list timeout;

        u32 rx_int_coal;
        u32 tx_int_coal;
        struct mii_if_info mii;
};

/* Static function declarations */
static void eth_port_init(struct mv643xx_private *mp);
static void eth_port_reset(struct mv643xx_private *mp);
static void eth_port_start(struct net_device *dev);

static void ethernet_phy_reset(struct mv643xx_private *mp);

static void eth_port_write_smi_reg(struct mv643xx_private *mp,
                                   unsigned int phy_reg, unsigned int value);

static void eth_port_read_smi_reg(struct mv643xx_private *mp,
                                  unsigned int phy_reg, unsigned int *value);

static void eth_clear_mib_counters(struct mv643xx_private *mp);

static ETH_FUNC_RET_STATUS eth_port_receive(struct mv643xx_private *mp,
                                            struct pkt_info *p_pkt_info);
static ETH_FUNC_RET_STATUS eth_rx_return_buff(struct mv643xx_private *mp,
                                              struct pkt_info *p_pkt_info);

static void eth_port_uc_addr_get(struct mv643xx_private *mp,
                                 unsigned char *p_addr);
static void eth_port_uc_addr_set(struct mv643xx_private *mp,
                                 unsigned char *p_addr);
static void eth_port_set_multicast_list(struct net_device *);
static void mv643xx_eth_port_enable_tx(struct mv643xx_private *mp,
                                                unsigned int queues);
static void mv643xx_eth_port_enable_rx(struct mv643xx_private *mp,
                                                unsigned int queues);
static unsigned int mv643xx_eth_port_disable_tx(struct mv643xx_private *mp);
static unsigned int mv643xx_eth_port_disable_rx(struct mv643xx_private *mp);
static int mv643xx_eth_open(struct net_device *);
static int mv643xx_eth_stop(struct net_device *);
static void eth_port_init_mac_tables(struct mv643xx_private *mp);
#ifdef MV643XX_NAPI
static int mv643xx_poll(struct napi_struct *napi, int budget);
#endif
static int ethernet_phy_get(struct mv643xx_private *mp);
static void ethernet_phy_set(struct mv643xx_private *mp, int phy_addr);
static int ethernet_phy_detect(struct mv643xx_private *mp);
static int mv643xx_mdio_read(struct net_device *dev, int phy_id, int location);
static void mv643xx_mdio_write(struct net_device *dev, int phy_id, int location, int val);
static int mv643xx_eth_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
static const struct ethtool_ops mv643xx_ethtool_ops;

static char mv643xx_driver_name[] = "mv643xx_eth";
static char mv643xx_driver_version[] = "1.0";

static inline u32 rdl(struct mv643xx_private *mp, int offset)
{
        return readl(mp->shared->eth_base + offset);
}

static inline void wrl(struct mv643xx_private *mp, int offset, u32 data)
{
        writel(data, mp->shared->eth_base + offset);
}

/*
 * Changes MTU (maximum transfer unit) of the gigabit ethenret port
 *
 * Input :      pointer to ethernet interface network device structure
 *              new mtu size
 * Output :     0 upon success, -EINVAL upon failure
 */
static int mv643xx_eth_change_mtu(struct net_device *dev, int new_mtu)
{
        if ((new_mtu > 9500) || (new_mtu < 64))
                return -EINVAL;

        dev->mtu = new_mtu;
        if (!netif_running(dev))
                return 0;

        /*
         * Stop and then re-open the interface. This will allocate RX
         * skbs of the new MTU.
         * There is a possible danger that the open will not succeed,
         * due to memory being full, which might fail the open function.
         */
        mv643xx_eth_stop(dev);
        if (mv643xx_eth_open(dev)) {
                printk(KERN_ERR "%s: Fatal error on opening device\n",
                        dev->name);
        }

        return 0;
}

/*
 * mv643xx_eth_rx_refill_descs
 *
 * Fills / refills RX queue on a certain gigabit ethernet port
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_rx_refill_descs(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct pkt_info pkt_info;
        struct sk_buff *skb;
        int unaligned;

        while (mp->rx_desc_count < mp->rx_ring_size) {
                skb = dev_alloc_skb(ETH_RX_SKB_SIZE + dma_get_cache_alignment());
                if (!skb)
                        break;
                mp->rx_desc_count++;
                unaligned = (u32)skb->data & (dma_get_cache_alignment() - 1);
                if (unaligned)
                        skb_reserve(skb, dma_get_cache_alignment() - unaligned);
                pkt_info.cmd_sts = ETH_RX_ENABLE_INTERRUPT;
                pkt_info.byte_cnt = ETH_RX_SKB_SIZE;
                pkt_info.buf_ptr = dma_map_single(NULL, skb->data,
                                        ETH_RX_SKB_SIZE, DMA_FROM_DEVICE);
                pkt_info.return_info = skb;
                if (eth_rx_return_buff(mp, &pkt_info) != ETH_OK) {
                        printk(KERN_ERR
                                "%s: Error allocating RX Ring\n", dev->name);
                        break;
                }
                skb_reserve(skb, ETH_HW_IP_ALIGN);
        }
        /*
         * If RX ring is empty of SKB, set a timer to try allocating
         * again at a later time.
         */
        if (mp->rx_desc_count == 0) {
                printk(KERN_INFO "%s: Rx ring is empty\n", dev->name);
                mp->timeout.expires = jiffies + (HZ / 10);      /* 100 mSec */
                add_timer(&mp->timeout);
        }
}

/*
 * mv643xx_eth_rx_refill_descs_timer_wrapper
 *
 * Timer routine to wake up RX queue filling task. This function is
 * used only in case the RX queue is empty, and all alloc_skb has
 * failed (due to out of memory event).
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static inline void mv643xx_eth_rx_refill_descs_timer_wrapper(unsigned long data)
{
        mv643xx_eth_rx_refill_descs((struct net_device *)data);
}

/*
 * mv643xx_eth_update_mac_address
 *
 * Update the MAC address of the port in the address table
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_update_mac_address(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        eth_port_init_mac_tables(mp);
        eth_port_uc_addr_set(mp, dev->dev_addr);
}

/*
 * mv643xx_eth_set_rx_mode
 *
 * Change from promiscuos to regular rx mode
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_set_rx_mode(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        u32 config_reg;

        config_reg = rdl(mp, PORT_CONFIG_REG(mp->port_num));
        if (dev->flags & IFF_PROMISC)
                config_reg |= (u32) UNICAST_PROMISCUOUS_MODE;
        else
                config_reg &= ~(u32) UNICAST_PROMISCUOUS_MODE;
        wrl(mp, PORT_CONFIG_REG(mp->port_num), config_reg);

        eth_port_set_multicast_list(dev);
}

/*
 * mv643xx_eth_set_mac_address
 *
 * Change the interface's mac address.
 * No special hardware thing should be done because interface is always
 * put in promiscuous mode.
 *
 * Input :      pointer to ethernet interface network device structure and
 *              a pointer to the designated entry to be added to the cache.
 * Output :     zero upon success, negative upon failure
 */
static int mv643xx_eth_set_mac_address(struct net_device *dev, void *addr)
{
        int i;

        for (i = 0; i < 6; i++)
                /* +2 is for the offset of the HW addr type */
                dev->dev_addr[i] = ((unsigned char *)addr)[i + 2];
        mv643xx_eth_update_mac_address(dev);
        return 0;
}

/*
 * mv643xx_eth_tx_timeout
 *
 * Called upon a timeout on transmitting a packet
 *
 * Input :      pointer to ethernet interface network device structure.
 * Output :     N/A
 */
static void mv643xx_eth_tx_timeout(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        printk(KERN_INFO "%s: TX timeout  ", dev->name);

        /* Do the reset outside of interrupt context */
        schedule_work(&mp->tx_timeout_task);
}

/*
 * mv643xx_eth_tx_timeout_task
 *
 * Actual routine to reset the adapter when a timeout on Tx has occurred
 */
static void mv643xx_eth_tx_timeout_task(struct work_struct *ugly)
{
        struct mv643xx_private *mp = container_of(ugly, struct mv643xx_private,
                                                  tx_timeout_task);
        struct net_device *dev = mp->dev;

        if (!netif_running(dev))
                return;

        netif_stop_queue(dev);

        eth_port_reset(mp);
        eth_port_start(dev);

        if (mp->tx_ring_size - mp->tx_desc_count >= MAX_DESCS_PER_SKB)
                netif_wake_queue(dev);
}

/**
 * mv643xx_eth_free_tx_descs - Free the tx desc data for completed descriptors
 *
 * If force is non-zero, frees uncompleted descriptors as well
 */
static int mv643xx_eth_free_tx_descs(struct net_device *dev, int force)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct eth_tx_desc *desc;
        u32 cmd_sts;
        struct sk_buff *skb;
        unsigned long flags;
        int tx_index;
        dma_addr_t addr;
        int count;
        int released = 0;

        while (mp->tx_desc_count > 0) {
                spin_lock_irqsave(&mp->lock, flags);

                /* tx_desc_count might have changed before acquiring the lock */
                if (mp->tx_desc_count <= 0) {
                        spin_unlock_irqrestore(&mp->lock, flags);
                        return released;
                }

                tx_index = mp->tx_used_desc_q;
                desc = &mp->p_tx_desc_area[tx_index];
                cmd_sts = desc->cmd_sts;

                if (!force && (cmd_sts & ETH_BUFFER_OWNED_BY_DMA)) {
                        spin_unlock_irqrestore(&mp->lock, flags);
                        return released;
                }

                mp->tx_used_desc_q = (tx_index + 1) % mp->tx_ring_size;
                mp->tx_desc_count--;

                addr = desc->buf_ptr;
                count = desc->byte_cnt;
                skb = mp->tx_skb[tx_index];
                if (skb)
                        mp->tx_skb[tx_index] = NULL;

                if (cmd_sts & ETH_ERROR_SUMMARY) {
                        printk("%s: Error in TX\n", dev->name);
                        dev->stats.tx_errors++;
                }

                spin_unlock_irqrestore(&mp->lock, flags);

                if (cmd_sts & ETH_TX_FIRST_DESC)
                        dma_unmap_single(NULL, addr, count, DMA_TO_DEVICE);
                else
                        dma_unmap_page(NULL, addr, count, DMA_TO_DEVICE);

                if (skb)
                        dev_kfree_skb_irq(skb);

                released = 1;
        }

        return released;
}

static void mv643xx_eth_free_completed_tx_descs(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        if (mv643xx_eth_free_tx_descs(dev, 0) &&
            mp->tx_ring_size - mp->tx_desc_count >= MAX_DESCS_PER_SKB)
                netif_wake_queue(dev);
}

static void mv643xx_eth_free_all_tx_descs(struct net_device *dev)
{
        mv643xx_eth_free_tx_descs(dev, 1);
}

/*
 * mv643xx_eth_receive
 *
 * This function is forward packets that are received from the port's
 * queues toward kernel core or FastRoute them to another interface.
 *
 * Input :      dev - a pointer to the required interface
 *              max - maximum number to receive (0 means unlimted)
 *
 * Output :     number of served packets
 */
static int mv643xx_eth_receive_queue(struct net_device *dev, int budget)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct net_device_stats *stats = &dev->stats;
        unsigned int received_packets = 0;
        struct sk_buff *skb;
        struct pkt_info pkt_info;

        while (budget-- > 0 && eth_port_receive(mp, &pkt_info) == ETH_OK) {
                dma_unmap_single(NULL, pkt_info.buf_ptr, ETH_RX_SKB_SIZE,
                                                        DMA_FROM_DEVICE);
                mp->rx_desc_count--;
                received_packets++;

                /*
                 * Update statistics.
                 * Note byte count includes 4 byte CRC count
                 */
                stats->rx_packets++;
                stats->rx_bytes += pkt_info.byte_cnt;
                skb = pkt_info.return_info;
                /*
                 * In case received a packet without first / last bits on OR
                 * the error summary bit is on, the packets needs to be dropeed.
                 */
                if (((pkt_info.cmd_sts
                                & (ETH_RX_FIRST_DESC | ETH_RX_LAST_DESC)) !=
                                        (ETH_RX_FIRST_DESC | ETH_RX_LAST_DESC))
                                || (pkt_info.cmd_sts & ETH_ERROR_SUMMARY)) {
                        stats->rx_dropped++;
                        if ((pkt_info.cmd_sts & (ETH_RX_FIRST_DESC |
                                                        ETH_RX_LAST_DESC)) !=
                                (ETH_RX_FIRST_DESC | ETH_RX_LAST_DESC)) {
                                if (net_ratelimit())
                                        printk(KERN_ERR
                                                "%s: Received packet spread "
                                                "on multiple descriptors\n",
                                                dev->name);
                        }
                        if (pkt_info.cmd_sts & ETH_ERROR_SUMMARY)
                                stats->rx_errors++;

                        dev_kfree_skb_irq(skb);
                } else {
                        /*
                         * The -4 is for the CRC in the trailer of the
                         * received packet
                         */
                        skb_put(skb, pkt_info.byte_cnt - 4);

                        if (pkt_info.cmd_sts & ETH_LAYER_4_CHECKSUM_OK) {
                                skb->ip_summed = CHECKSUM_UNNECESSARY;
                                skb->csum = htons(
                                        (pkt_info.cmd_sts & 0x0007fff8) >> 3);
                        }
                        skb->protocol = eth_type_trans(skb, dev);
#ifdef MV643XX_NAPI
                        netif_receive_skb(skb);
#else
                        netif_rx(skb);
#endif
                }
                dev->last_rx = jiffies;
        }
        mv643xx_eth_rx_refill_descs(dev);       /* Fill RX ring with skb's */

        return received_packets;
}

/* Set the mv643xx port configuration register for the speed/duplex mode. */
static void mv643xx_eth_update_pscr(struct net_device *dev,
                                    struct ethtool_cmd *ecmd)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        int port_num = mp->port_num;
        u32 o_pscr, n_pscr;
        unsigned int queues;

        o_pscr = rdl(mp, PORT_SERIAL_CONTROL_REG(port_num));
        n_pscr = o_pscr;

        /* clear speed, duplex and rx buffer size fields */
        n_pscr &= ~(SET_MII_SPEED_TO_100  |
                   SET_GMII_SPEED_TO_1000 |
                   SET_FULL_DUPLEX_MODE   |
                   MAX_RX_PACKET_MASK);

        if (ecmd->duplex == DUPLEX_FULL)
                n_pscr |= SET_FULL_DUPLEX_MODE;

        if (ecmd->speed == SPEED_1000)
                n_pscr |= SET_GMII_SPEED_TO_1000 |
                          MAX_RX_PACKET_9700BYTE;
        else {
                if (ecmd->speed == SPEED_100)
                        n_pscr |= SET_MII_SPEED_TO_100;
                n_pscr |= MAX_RX_PACKET_1522BYTE;
        }

        if (n_pscr != o_pscr) {
                if ((o_pscr & SERIAL_PORT_ENABLE) == 0)
                        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), n_pscr);
                else {
                        queues = mv643xx_eth_port_disable_tx(mp);

                        o_pscr &= ~SERIAL_PORT_ENABLE;
                        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), o_pscr);
                        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), n_pscr);
                        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), n_pscr);
                        if (queues)
                                mv643xx_eth_port_enable_tx(mp, queues);
                }
        }
}

/*
 * mv643xx_eth_int_handler
 *
 * Main interrupt handler for the gigbit ethernet ports
 *
 * Input :      irq     - irq number (not used)
 *              dev_id  - a pointer to the required interface's data structure
 *              regs    - not used
 * Output :     N/A
 */

static irqreturn_t mv643xx_eth_int_handler(int irq, void *dev_id)
{
        struct net_device *dev = (struct net_device *)dev_id;
        struct mv643xx_private *mp = netdev_priv(dev);
        u32 eth_int_cause, eth_int_cause_ext = 0;
        unsigned int port_num = mp->port_num;

        /* Read interrupt cause registers */
        eth_int_cause = rdl(mp, INTERRUPT_CAUSE_REG(port_num)) &
                                                ETH_INT_UNMASK_ALL;
        if (eth_int_cause & ETH_INT_CAUSE_EXT) {
                eth_int_cause_ext = rdl(mp,
                        INTERRUPT_CAUSE_EXTEND_REG(port_num)) &
                                                ETH_INT_UNMASK_ALL_EXT;
                wrl(mp, INTERRUPT_CAUSE_EXTEND_REG(port_num),
                                                        ~eth_int_cause_ext);
        }

        /* PHY status changed */
        if (eth_int_cause_ext & (ETH_INT_CAUSE_PHY | ETH_INT_CAUSE_STATE)) {
                struct ethtool_cmd cmd;

                if (mii_link_ok(&mp->mii)) {
                        mii_ethtool_gset(&mp->mii, &cmd);
                        mv643xx_eth_update_pscr(dev, &cmd);
                        mv643xx_eth_port_enable_tx(mp, ETH_TX_QUEUES_ENABLED);
                        if (!netif_carrier_ok(dev)) {
                                netif_carrier_on(dev);
                                if (mp->tx_ring_size - mp->tx_desc_count >=
                                                        MAX_DESCS_PER_SKB)
                                        netif_wake_queue(dev);
                        }
                } else if (netif_carrier_ok(dev)) {
                        netif_stop_queue(dev);
                        netif_carrier_off(dev);
                }
        }

#ifdef MV643XX_NAPI
        if (eth_int_cause & ETH_INT_CAUSE_RX) {
                /* schedule the NAPI poll routine to maintain port */
                wrl(mp, INTERRUPT_MASK_REG(port_num), ETH_INT_MASK_ALL);

                /* wait for previous write to complete */
                rdl(mp, INTERRUPT_MASK_REG(port_num));

                netif_rx_schedule(dev, &mp->napi);
        }
#else
        if (eth_int_cause & ETH_INT_CAUSE_RX)
                mv643xx_eth_receive_queue(dev, INT_MAX);
#endif
        if (eth_int_cause_ext & ETH_INT_CAUSE_TX)
                mv643xx_eth_free_completed_tx_descs(dev);

        /*
         * If no real interrupt occured, exit.
         * This can happen when using gigE interrupt coalescing mechanism.
         */
        if ((eth_int_cause == 0x0) && (eth_int_cause_ext == 0x0))
                return IRQ_NONE;

        return IRQ_HANDLED;
}

#ifdef MV643XX_COAL

/*
 * eth_port_set_rx_coal - Sets coalescing interrupt mechanism on RX path
 *
 * DESCRIPTION:
 *      This routine sets the RX coalescing interrupt mechanism parameter.
 *      This parameter is a timeout counter, that counts in 64 t_clk
 *      chunks ; that when timeout event occurs a maskable interrupt
 *      occurs.
 *      The parameter is calculated using the tClk of the MV-643xx chip
 *      , and the required delay of the interrupt in usec.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet port
 *      unsigned int delay              Delay in usec
 *
 * OUTPUT:
 *      Interrupt coalescing mechanism value is set in MV-643xx chip.
 *
 * RETURN:
 *      The interrupt coalescing value set in the gigE port.
 *
 */
static unsigned int eth_port_set_rx_coal(struct mv643xx_private *mp,
                                        unsigned int delay)
{
        unsigned int port_num = mp->port_num;
        unsigned int coal = ((mp->shared->t_clk / 1000000) * delay) / 64;

        /* Set RX Coalescing mechanism */
        wrl(mp, SDMA_CONFIG_REG(port_num),
                ((coal & 0x3fff) << 8) |
                (rdl(mp, SDMA_CONFIG_REG(port_num))
                        & 0xffc000ff));

        return coal;
}
#endif

/*
 * eth_port_set_tx_coal - Sets coalescing interrupt mechanism on TX path
 *
 * DESCRIPTION:
 *      This routine sets the TX coalescing interrupt mechanism parameter.
 *      This parameter is a timeout counter, that counts in 64 t_clk
 *      chunks ; that when timeout event occurs a maskable interrupt
 *      occurs.
 *      The parameter is calculated using the t_cLK frequency of the
 *      MV-643xx chip and the required delay in the interrupt in uSec
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet port
 *      unsigned int delay              Delay in uSeconds
 *
 * OUTPUT:
 *      Interrupt coalescing mechanism value is set in MV-643xx chip.
 *
 * RETURN:
 *      The interrupt coalescing value set in the gigE port.
 *
 */
static unsigned int eth_port_set_tx_coal(struct mv643xx_private *mp,
                                        unsigned int delay)
{
        unsigned int coal = ((mp->shared->t_clk / 1000000) * delay) / 64;

        /* Set TX Coalescing mechanism */
        wrl(mp, TX_FIFO_URGENT_THRESHOLD_REG(mp->port_num), coal << 4);

        return coal;
}

/*
 * ether_init_rx_desc_ring - Curve a Rx chain desc list and buffer in memory.
 *
 * DESCRIPTION:
 *      This function prepares a Rx chained list of descriptors and packet
 *      buffers in a form of a ring. The routine must be called after port
 *      initialization routine and before port start routine.
 *      The Ethernet SDMA engine uses CPU bus addresses to access the various
 *      devices in the system (i.e. DRAM). This function uses the ethernet
 *      struct 'virtual to physical' routine (set by the user) to set the ring
 *      with physical addresses.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port Control srtuct.
 *
 * OUTPUT:
 *      The routine updates the Ethernet port control struct with information
 *      regarding the Rx descriptors and buffers.
 *
 * RETURN:
 *      None.
 */
static void ether_init_rx_desc_ring(struct mv643xx_private *mp)
{
        volatile struct eth_rx_desc *p_rx_desc;
        int rx_desc_num = mp->rx_ring_size;
        int i;

        /* initialize the next_desc_ptr links in the Rx descriptors ring */
        p_rx_desc = (struct eth_rx_desc *)mp->p_rx_desc_area;
        for (i = 0; i < rx_desc_num; i++) {
                p_rx_desc[i].next_desc_ptr = mp->rx_desc_dma +
                        ((i + 1) % rx_desc_num) * sizeof(struct eth_rx_desc);
        }

        /* Save Rx desc pointer to driver struct. */
        mp->rx_curr_desc_q = 0;
        mp->rx_used_desc_q = 0;

        mp->rx_desc_area_size = rx_desc_num * sizeof(struct eth_rx_desc);
}

/*
 * ether_init_tx_desc_ring - Curve a Tx chain desc list and buffer in memory.
 *
 * DESCRIPTION:
 *      This function prepares a Tx chained list of descriptors and packet
 *      buffers in a form of a ring. The routine must be called after port
 *      initialization routine and before port start routine.
 *      The Ethernet SDMA engine uses CPU bus addresses to access the various
 *      devices in the system (i.e. DRAM). This function uses the ethernet
 *      struct 'virtual to physical' routine (set by the user) to set the ring
 *      with physical addresses.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port Control srtuct.
 *
 * OUTPUT:
 *      The routine updates the Ethernet port control struct with information
 *      regarding the Tx descriptors and buffers.
 *
 * RETURN:
 *      None.
 */
static void ether_init_tx_desc_ring(struct mv643xx_private *mp)
{
        int tx_desc_num = mp->tx_ring_size;
        struct eth_tx_desc *p_tx_desc;
        int i;

        /* Initialize the next_desc_ptr links in the Tx descriptors ring */
        p_tx_desc = (struct eth_tx_desc *)mp->p_tx_desc_area;
        for (i = 0; i < tx_desc_num; i++) {
                p_tx_desc[i].next_desc_ptr = mp->tx_desc_dma +
                        ((i + 1) % tx_desc_num) * sizeof(struct eth_tx_desc);
        }

        mp->tx_curr_desc_q = 0;
        mp->tx_used_desc_q = 0;

        mp->tx_desc_area_size = tx_desc_num * sizeof(struct eth_tx_desc);
}

static int mv643xx_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        int err;

        spin_lock_irq(&mp->lock);
        err = mii_ethtool_sset(&mp->mii, cmd);
        spin_unlock_irq(&mp->lock);

        return err;
}

static int mv643xx_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        int err;

        spin_lock_irq(&mp->lock);
        err = mii_ethtool_gset(&mp->mii, cmd);
        spin_unlock_irq(&mp->lock);

        /* The PHY may support 1000baseT_Half, but the mv643xx does not */
        cmd->supported &= ~SUPPORTED_1000baseT_Half;
        cmd->advertising &= ~ADVERTISED_1000baseT_Half;

        return err;
}

/*
 * mv643xx_eth_open
 *
 * This function is called when openning the network device. The function
 * should initialize all the hardware, initialize cyclic Rx/Tx
 * descriptors chain and buffers and allocate an IRQ to the network
 * device.
 *
 * Input :      a pointer to the network device structure
 *
 * Output :     zero of success , nonzero if fails.
 */

static int mv643xx_eth_open(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;
        unsigned int size;
        int err;

        /* Clear any pending ethernet port interrupts */
        wrl(mp, INTERRUPT_CAUSE_REG(port_num), 0);
        wrl(mp, INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);
        /* wait for previous write to complete */
        rdl(mp, INTERRUPT_CAUSE_EXTEND_REG(port_num));

        err = request_irq(dev->irq, mv643xx_eth_int_handler,
                        IRQF_SHARED | IRQF_SAMPLE_RANDOM, dev->name, dev);
        if (err) {
                printk(KERN_ERR "%s: Can not assign IRQ\n", dev->name);
                return -EAGAIN;
        }

        eth_port_init(mp);

        memset(&mp->timeout, 0, sizeof(struct timer_list));
        mp->timeout.function = mv643xx_eth_rx_refill_descs_timer_wrapper;
        mp->timeout.data = (unsigned long)dev;

        /* Allocate RX and TX skb rings */
        mp->rx_skb = kmalloc(sizeof(*mp->rx_skb) * mp->rx_ring_size,
                                                                GFP_KERNEL);
        if (!mp->rx_skb) {
                printk(KERN_ERR "%s: Cannot allocate Rx skb ring\n", dev->name);
                err = -ENOMEM;
                goto out_free_irq;
        }
        mp->tx_skb = kmalloc(sizeof(*mp->tx_skb) * mp->tx_ring_size,
                                                                GFP_KERNEL);
        if (!mp->tx_skb) {
                printk(KERN_ERR "%s: Cannot allocate Tx skb ring\n", dev->name);
                err = -ENOMEM;
                goto out_free_rx_skb;
        }

        /* Allocate TX ring */
        mp->tx_desc_count = 0;
        size = mp->tx_ring_size * sizeof(struct eth_tx_desc);
        mp->tx_desc_area_size = size;

        if (mp->tx_sram_size) {
                mp->p_tx_desc_area = ioremap(mp->tx_sram_addr,
                                                        mp->tx_sram_size);
                mp->tx_desc_dma = mp->tx_sram_addr;
        } else
                mp->p_tx_desc_area = dma_alloc_coherent(NULL, size,
                                                        &mp->tx_desc_dma,
                                                        GFP_KERNEL);

        if (!mp->p_tx_desc_area) {
                printk(KERN_ERR "%s: Cannot allocate Tx Ring (size %d bytes)\n",
                                                        dev->name, size);
                err = -ENOMEM;
                goto out_free_tx_skb;
        }
        BUG_ON((u32) mp->p_tx_desc_area & 0xf); /* check 16-byte alignment */
        memset((void *)mp->p_tx_desc_area, 0, mp->tx_desc_area_size);

        ether_init_tx_desc_ring(mp);

        /* Allocate RX ring */
        mp->rx_desc_count = 0;
        size = mp->rx_ring_size * sizeof(struct eth_rx_desc);
        mp->rx_desc_area_size = size;

        if (mp->rx_sram_size) {
                mp->p_rx_desc_area = ioremap(mp->rx_sram_addr,
                                                        mp->rx_sram_size);
                mp->rx_desc_dma = mp->rx_sram_addr;
        } else
                mp->p_rx_desc_area = dma_alloc_coherent(NULL, size,
                                                        &mp->rx_desc_dma,
                                                        GFP_KERNEL);

        if (!mp->p_rx_desc_area) {
                printk(KERN_ERR "%s: Cannot allocate Rx ring (size %d bytes)\n",
                                                        dev->name, size);
                printk(KERN_ERR "%s: Freeing previously allocated TX queues...",
                                                        dev->name);
                if (mp->rx_sram_size)
                        iounmap(mp->p_tx_desc_area);
                else
                        dma_free_coherent(NULL, mp->tx_desc_area_size,
                                        mp->p_tx_desc_area, mp->tx_desc_dma);
                err = -ENOMEM;
                goto out_free_tx_skb;
        }
        memset((void *)mp->p_rx_desc_area, 0, size);

        ether_init_rx_desc_ring(mp);

        mv643xx_eth_rx_refill_descs(dev);       /* Fill RX ring with skb's */

#ifdef MV643XX_NAPI
        napi_enable(&mp->napi);
#endif

        eth_port_start(dev);

        /* Interrupt Coalescing */

#ifdef MV643XX_COAL
        mp->rx_int_coal =
                eth_port_set_rx_coal(mp, MV643XX_RX_COAL);
#endif

        mp->tx_int_coal =
                eth_port_set_tx_coal(mp, MV643XX_TX_COAL);

        /* Unmask phy and link status changes interrupts */
        wrl(mp, INTERRUPT_EXTEND_MASK_REG(port_num), ETH_INT_UNMASK_ALL_EXT);

        /* Unmask RX buffer and TX end interrupt */
        wrl(mp, INTERRUPT_MASK_REG(port_num), ETH_INT_UNMASK_ALL);

        return 0;

out_free_tx_skb:
        kfree(mp->tx_skb);
out_free_rx_skb:
        kfree(mp->rx_skb);
out_free_irq:
        free_irq(dev->irq, dev);

        return err;
}

static void mv643xx_eth_free_tx_rings(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        /* Stop Tx Queues */
        mv643xx_eth_port_disable_tx(mp);

        /* Free outstanding skb's on TX ring */
        mv643xx_eth_free_all_tx_descs(dev);

        BUG_ON(mp->tx_used_desc_q != mp->tx_curr_desc_q);

        /* Free TX ring */
        if (mp->tx_sram_size)
                iounmap(mp->p_tx_desc_area);
        else
                dma_free_coherent(NULL, mp->tx_desc_area_size,
                                mp->p_tx_desc_area, mp->tx_desc_dma);
}

static void mv643xx_eth_free_rx_rings(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        int curr;

        /* Stop RX Queues */
        mv643xx_eth_port_disable_rx(mp);

        /* Free preallocated skb's on RX rings */
        for (curr = 0; mp->rx_desc_count && curr < mp->rx_ring_size; curr++) {
                if (mp->rx_skb[curr]) {
                        dev_kfree_skb(mp->rx_skb[curr]);
                        mp->rx_desc_count--;
                }
        }

        if (mp->rx_desc_count)
                printk(KERN_ERR
                        "%s: Error in freeing Rx Ring. %d skb's still"
                        " stuck in RX Ring - ignoring them\n", dev->name,
                        mp->rx_desc_count);
        /* Free RX ring */
        if (mp->rx_sram_size)
                iounmap(mp->p_rx_desc_area);
        else
                dma_free_coherent(NULL, mp->rx_desc_area_size,
                                mp->p_rx_desc_area, mp->rx_desc_dma);
}

/*
 * mv643xx_eth_stop
 *
 * This function is used when closing the network device.
 * It updates the hardware,
 * release all memory that holds buffers and descriptors and release the IRQ.
 * Input :      a pointer to the device structure
 * Output :     zero if success , nonzero if fails
 */

static int mv643xx_eth_stop(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;

        /* Mask all interrupts on ethernet port */
        wrl(mp, INTERRUPT_MASK_REG(port_num), ETH_INT_MASK_ALL);
        /* wait for previous write to complete */
        rdl(mp, INTERRUPT_MASK_REG(port_num));

#ifdef MV643XX_NAPI
        napi_disable(&mp->napi);
#endif
        netif_carrier_off(dev);
        netif_stop_queue(dev);

        eth_port_reset(mp);

        mv643xx_eth_free_tx_rings(dev);
        mv643xx_eth_free_rx_rings(dev);

        free_irq(dev->irq, dev);

        return 0;
}

#ifdef MV643XX_NAPI
/*
 * mv643xx_poll
 *
 * This function is used in case of NAPI
 */
static int mv643xx_poll(struct napi_struct *napi, int budget)
{
        struct mv643xx_private *mp = container_of(napi, struct mv643xx_private, napi);
        struct net_device *dev = mp->dev;
        unsigned int port_num = mp->port_num;
        int work_done;

#ifdef MV643XX_TX_FAST_REFILL
        if (++mp->tx_clean_threshold > 5) {
                mv643xx_eth_free_completed_tx_descs(dev);
                mp->tx_clean_threshold = 0;
        }
#endif

        work_done = 0;
        if ((rdl(mp, RX_CURRENT_QUEUE_DESC_PTR_0(port_num)))
            != (u32) mp->rx_used_desc_q)
                work_done = mv643xx_eth_receive_queue(dev, budget);

        if (work_done < budget) {
                netif_rx_complete(dev, napi);
                wrl(mp, INTERRUPT_CAUSE_REG(port_num), 0);
                wrl(mp, INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);
                wrl(mp, INTERRUPT_MASK_REG(port_num), ETH_INT_UNMASK_ALL);
        }

        return work_done;
}
#endif

/**
 * has_tiny_unaligned_frags - check if skb has any small, unaligned fragments
 *
 * Hardware can't handle unaligned fragments smaller than 9 bytes.
 * This helper function detects that case.
 */

static inline unsigned int has_tiny_unaligned_frags(struct sk_buff *skb)
{
        unsigned int frag;
        skb_frag_t *fragp;

        for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
                fragp = &skb_shinfo(skb)->frags[frag];
                if (fragp->size <= 8 && fragp->page_offset & 0x7)
                        return 1;
        }
        return 0;
}

/**
 * eth_alloc_tx_desc_index - return the index of the next available tx desc
 */
static int eth_alloc_tx_desc_index(struct mv643xx_private *mp)
{
        int tx_desc_curr;

        BUG_ON(mp->tx_desc_count >= mp->tx_ring_size);

        tx_desc_curr = mp->tx_curr_desc_q;
        mp->tx_curr_desc_q = (tx_desc_curr + 1) % mp->tx_ring_size;

        BUG_ON(mp->tx_curr_desc_q == mp->tx_used_desc_q);

        return tx_desc_curr;
}

/**
 * eth_tx_fill_frag_descs - fill tx hw descriptors for an skb's fragments.
 *
 * Ensure the data for each fragment to be transmitted is mapped properly,
 * then fill in descriptors in the tx hw queue.
 */
static void eth_tx_fill_frag_descs(struct mv643xx_private *mp,
                                   struct sk_buff *skb)
{
        int frag;
        int tx_index;
        struct eth_tx_desc *desc;

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

                tx_index = eth_alloc_tx_desc_index(mp);
                desc = &mp->p_tx_desc_area[tx_index];

                desc->cmd_sts = ETH_BUFFER_OWNED_BY_DMA;
                /* Last Frag enables interrupt and frees the skb */
                if (frag == (skb_shinfo(skb)->nr_frags - 1)) {
                        desc->cmd_sts |= ETH_ZERO_PADDING |
                                         ETH_TX_LAST_DESC |
                                         ETH_TX_ENABLE_INTERRUPT;
                        mp->tx_skb[tx_index] = skb;
                } else
                        mp->tx_skb[tx_index] = NULL;

                desc = &mp->p_tx_desc_area[tx_index];
                desc->l4i_chk = 0;
                desc->byte_cnt = this_frag->size;
                desc->buf_ptr = dma_map_page(NULL, this_frag->page,
                                                this_frag->page_offset,
                                                this_frag->size,
                                                DMA_TO_DEVICE);
        }
}

static inline __be16 sum16_as_be(__sum16 sum)
{
        return (__force __be16)sum;
}

/**
 * eth_tx_submit_descs_for_skb - submit data from an skb to the tx hw
 *
 * Ensure the data for an skb to be transmitted is mapped properly,
 * then fill in descriptors in the tx hw queue and start the hardware.
 */
static void eth_tx_submit_descs_for_skb(struct mv643xx_private *mp,
                                        struct sk_buff *skb)
{
        int tx_index;
        struct eth_tx_desc *desc;
        u32 cmd_sts;
        int length;
        int nr_frags = skb_shinfo(skb)->nr_frags;

        cmd_sts = ETH_TX_FIRST_DESC | ETH_GEN_CRC | ETH_BUFFER_OWNED_BY_DMA;

        tx_index = eth_alloc_tx_desc_index(mp);
        desc = &mp->p_tx_desc_area[tx_index];

        if (nr_frags) {
                eth_tx_fill_frag_descs(mp, skb);

                length = skb_headlen(skb);
                mp->tx_skb[tx_index] = NULL;
        } else {
                cmd_sts |= ETH_ZERO_PADDING |
                           ETH_TX_LAST_DESC |
                           ETH_TX_ENABLE_INTERRUPT;
                length = skb->len;
                mp->tx_skb[tx_index] = skb;
        }

        desc->byte_cnt = length;
        desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);

        if (skb->ip_summed == CHECKSUM_PARTIAL) {
                BUG_ON(skb->protocol != htons(ETH_P_IP));

                cmd_sts |= ETH_GEN_TCP_UDP_CHECKSUM |
                           ETH_GEN_IP_V_4_CHECKSUM  |
                           ip_hdr(skb)->ihl << ETH_TX_IHL_SHIFT;

                switch (ip_hdr(skb)->protocol) {
                case IPPROTO_UDP:
                        cmd_sts |= ETH_UDP_FRAME;
                        desc->l4i_chk = ntohs(sum16_as_be(udp_hdr(skb)->check));
                        break;
                case IPPROTO_TCP:
                        desc->l4i_chk = ntohs(sum16_as_be(tcp_hdr(skb)->check));
                        break;
                default:
                        BUG();
                }
        } else {
                /* Errata BTS #50, IHL must be 5 if no HW checksum */
                cmd_sts |= 5 << ETH_TX_IHL_SHIFT;
                desc->l4i_chk = 0;
        }

        /* ensure all other descriptors are written before first cmd_sts */
        wmb();
        desc->cmd_sts = cmd_sts;

        /* ensure all descriptors are written before poking hardware */
        wmb();
        mv643xx_eth_port_enable_tx(mp, ETH_TX_QUEUES_ENABLED);

        mp->tx_desc_count += nr_frags + 1;
}

/**
 * mv643xx_eth_start_xmit - queue an skb to the hardware for transmission
 *
 */
static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct net_device_stats *stats = &dev->stats;
        unsigned long flags;

        BUG_ON(netif_queue_stopped(dev));

        if (has_tiny_unaligned_frags(skb) && __skb_linearize(skb)) {
                stats->tx_dropped++;
                printk(KERN_DEBUG "%s: failed to linearize tiny "
                                "unaligned fragment\n", dev->name);
                return NETDEV_TX_BUSY;
        }

        spin_lock_irqsave(&mp->lock, flags);

        if (mp->tx_ring_size - mp->tx_desc_count < MAX_DESCS_PER_SKB) {
                printk(KERN_ERR "%s: transmit with queue full\n", dev->name);
                netif_stop_queue(dev);
                spin_unlock_irqrestore(&mp->lock, flags);
                return NETDEV_TX_BUSY;
        }

        eth_tx_submit_descs_for_skb(mp, skb);
        stats->tx_bytes += skb->len;
        stats->tx_packets++;
        dev->trans_start = jiffies;

        if (mp->tx_ring_size - mp->tx_desc_count < MAX_DESCS_PER_SKB)
                netif_stop_queue(dev);

        spin_unlock_irqrestore(&mp->lock, flags);

        return NETDEV_TX_OK;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void mv643xx_netpoll(struct net_device *netdev)
{
        struct mv643xx_private *mp = netdev_priv(netdev);
        int port_num = mp->port_num;

        wrl(mp, INTERRUPT_MASK_REG(port_num), ETH_INT_MASK_ALL);
        /* wait for previous write to complete */
        rdl(mp, INTERRUPT_MASK_REG(port_num));

        mv643xx_eth_int_handler(netdev->irq, netdev);

        wrl(mp, INTERRUPT_MASK_REG(port_num), ETH_INT_UNMASK_ALL);
}
#endif

static void mv643xx_init_ethtool_cmd(struct net_device *dev, int phy_address,
                                     int speed, int duplex,
                                     struct ethtool_cmd *cmd)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        memset(cmd, 0, sizeof(*cmd));

        cmd->port = PORT_MII;
        cmd->transceiver = XCVR_INTERNAL;
        cmd->phy_address = phy_address;

        if (speed == 0) {
                cmd->autoneg = AUTONEG_ENABLE;
                /* mii lib checks, but doesn't use speed on AUTONEG_ENABLE */
                cmd->speed = SPEED_100;
                cmd->advertising = ADVERTISED_10baseT_Half  |
                                   ADVERTISED_10baseT_Full  |
                                   ADVERTISED_100baseT_Half |
                                   ADVERTISED_100baseT_Full;
                if (mp->mii.supports_gmii)
                        cmd->advertising |= ADVERTISED_1000baseT_Full;
        } else {
                cmd->autoneg = AUTONEG_DISABLE;
                cmd->speed = speed;
                cmd->duplex = duplex;
        }
}

/*/
 * mv643xx_eth_probe
 *
 * First function called after registering the network device.
 * It's purpose is to initialize the device as an ethernet device,
 * fill the ethernet device structure with pointers * to functions,
 * and set the MAC address of the interface
 *
 * Input :      struct device *
 * Output :     -ENOMEM if failed , 0 if success
 */
static int mv643xx_eth_probe(struct platform_device *pdev)
{
        struct mv643xx_eth_platform_data *pd;
        int port_num;
        struct mv643xx_private *mp;
        struct net_device *dev;
        u8 *p;
        struct resource *res;
        int err;
        struct ethtool_cmd cmd;
        int duplex = DUPLEX_HALF;
        int speed = 0;                  /* default to auto-negotiation */
        DECLARE_MAC_BUF(mac);

        pd = pdev->dev.platform_data;
        if (pd == NULL) {
                printk(KERN_ERR "No mv643xx_eth_platform_data\n");
                return -ENODEV;
        }

        if (pd->shared == NULL) {
                printk(KERN_ERR "No mv643xx_eth_platform_data->shared\n");
                return -ENODEV;
        }

        dev = alloc_etherdev(sizeof(struct mv643xx_private));
        if (!dev)
                return -ENOMEM;

        platform_set_drvdata(pdev, dev);

        mp = netdev_priv(dev);
        mp->dev = dev;
#ifdef MV643XX_NAPI
        netif_napi_add(dev, &mp->napi, mv643xx_poll, 64);
#endif

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        BUG_ON(!res);
        dev->irq = res->start;

        dev->open = mv643xx_eth_open;
        dev->stop = mv643xx_eth_stop;
        dev->hard_start_xmit = mv643xx_eth_start_xmit;
        dev->set_mac_address = mv643xx_eth_set_mac_address;
        dev->set_multicast_list = mv643xx_eth_set_rx_mode;

        /* No need to Tx Timeout */
        dev->tx_timeout = mv643xx_eth_tx_timeout;

#ifdef CONFIG_NET_POLL_CONTROLLER
        dev->poll_controller = mv643xx_netpoll;
#endif

        dev->watchdog_timeo = 2 * HZ;
        dev->base_addr = 0;
        dev->change_mtu = mv643xx_eth_change_mtu;
        dev->do_ioctl = mv643xx_eth_do_ioctl;
        SET_ETHTOOL_OPS(dev, &mv643xx_ethtool_ops);

#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
#ifdef MAX_SKB_FRAGS
        /*
         * Zero copy can only work if we use Discovery II memory. Else, we will
         * have to map the buffers to ISA memory which is only 16 MB
         */
        dev->features = NETIF_F_SG | NETIF_F_IP_CSUM;
#endif
#endif

        /* Configure the timeout task */
        INIT_WORK(&mp->tx_timeout_task, mv643xx_eth_tx_timeout_task);

        spin_lock_init(&mp->lock);

        mp->shared = platform_get_drvdata(pd->shared);
        port_num = mp->port_num = pd->port_number;

        if (mp->shared->win_protect)
                wrl(mp, WINDOW_PROTECT(port_num), mp->shared->win_protect);

        mp->shared_smi = mp->shared;
        if (pd->shared_smi != NULL)
                mp->shared_smi = platform_get_drvdata(pd->shared_smi);

        /* set default config values */
        eth_port_uc_addr_get(mp, dev->dev_addr);
        mp->rx_ring_size = PORT_DEFAULT_RECEIVE_QUEUE_SIZE;
        mp->tx_ring_size = PORT_DEFAULT_TRANSMIT_QUEUE_SIZE;

        if (is_valid_ether_addr(pd->mac_addr))
                memcpy(dev->dev_addr, pd->mac_addr, 6);

        if (pd->phy_addr || pd->force_phy_addr)
                ethernet_phy_set(mp, pd->phy_addr);

        if (pd->rx_queue_size)
                mp->rx_ring_size = pd->rx_queue_size;

        if (pd->tx_queue_size)
                mp->tx_ring_size = pd->tx_queue_size;

        if (pd->tx_sram_size) {
                mp->tx_sram_size = pd->tx_sram_size;
                mp->tx_sram_addr = pd->tx_sram_addr;
        }

        if (pd->rx_sram_size) {
                mp->rx_sram_size = pd->rx_sram_size;
                mp->rx_sram_addr = pd->rx_sram_addr;
        }

        duplex = pd->duplex;
        speed = pd->speed;

        /* Hook up MII support for ethtool */
        mp->mii.dev = dev;
        mp->mii.mdio_read = mv643xx_mdio_read;
        mp->mii.mdio_write = mv643xx_mdio_write;
        mp->mii.phy_id = ethernet_phy_get(mp);
        mp->mii.phy_id_mask = 0x3f;
        mp->mii.reg_num_mask = 0x1f;

        err = ethernet_phy_detect(mp);
        if (err) {
                pr_debug("%s: No PHY detected at addr %d\n",
                                dev->name, ethernet_phy_get(mp));
                goto out;
        }

        ethernet_phy_reset(mp);
        mp->mii.supports_gmii = mii_check_gmii_support(&mp->mii);
        mv643xx_init_ethtool_cmd(dev, mp->mii.phy_id, speed, duplex, &cmd);
        mv643xx_eth_update_pscr(dev, &cmd);
        mv643xx_set_settings(dev, &cmd);

        SET_NETDEV_DEV(dev, &pdev->dev);
        err = register_netdev(dev);
        if (err)
                goto out;

        p = dev->dev_addr;
        printk(KERN_NOTICE
                "%s: port %d with MAC address %s\n",
                dev->name, port_num, print_mac(mac, p));

        if (dev->features & NETIF_F_SG)
                printk(KERN_NOTICE "%s: Scatter Gather Enabled\n", dev->name);

        if (dev->features & NETIF_F_IP_CSUM)
                printk(KERN_NOTICE "%s: TX TCP/IP Checksumming Supported\n",
                                                                dev->name);

#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
        printk(KERN_NOTICE "%s: RX TCP/UDP Checksum Offload ON \n", dev->name);
#endif

#ifdef MV643XX_COAL
        printk(KERN_NOTICE "%s: TX and RX Interrupt Coalescing ON \n",
                                                                dev->name);
#endif

#ifdef MV643XX_NAPI
        printk(KERN_NOTICE "%s: RX NAPI Enabled \n", dev->name);
#endif

        if (mp->tx_sram_size > 0)
                printk(KERN_NOTICE "%s: Using SRAM\n", dev->name);

        return 0;

out:
        free_netdev(dev);

        return err;
}

static int mv643xx_eth_remove(struct platform_device *pdev)
{
        struct net_device *dev = platform_get_drvdata(pdev);

        unregister_netdev(dev);
        flush_scheduled_work();

        free_netdev(dev);
        platform_set_drvdata(pdev, NULL);
        return 0;
}

static void mv643xx_eth_conf_mbus_windows(struct mv643xx_shared_private *msp,
                                          struct mbus_dram_target_info *dram)
{
        void __iomem *base = msp->eth_base;
        u32 win_enable;
        u32 win_protect;
        int i;

        for (i = 0; i < 6; i++) {
                writel(0, base + WINDOW_BASE(i));
                writel(0, base + WINDOW_SIZE(i));
                if (i < 4)
                        writel(0, base + WINDOW_REMAP_HIGH(i));
        }

        win_enable = 0x3f;
        win_protect = 0;

        for (i = 0; i < dram->num_cs; i++) {
                struct mbus_dram_window *cs = dram->cs + i;

                writel((cs->base & 0xffff0000) |
                        (cs->mbus_attr << 8) |
                        dram->mbus_dram_target_id, base + WINDOW_BASE(i));
                writel((cs->size - 1) & 0xffff0000, base + WINDOW_SIZE(i));

                win_enable &= ~(1 << i);
                win_protect |= 3 << (2 * i);
        }

        writel(win_enable, base + WINDOW_BAR_ENABLE);
        msp->win_protect = win_protect;
}

static int mv643xx_eth_shared_probe(struct platform_device *pdev)
{
        static int mv643xx_version_printed = 0;
        struct mv643xx_eth_shared_platform_data *pd = pdev->dev.platform_data;
        struct mv643xx_shared_private *msp;
        struct resource *res;
        int ret;

        if (!mv643xx_version_printed++)
                printk(KERN_NOTICE "MV-643xx 10/100/1000 Ethernet Driver\n");

        ret = -EINVAL;
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL)
                goto out;

        ret = -ENOMEM;
        msp = kmalloc(sizeof(*msp), GFP_KERNEL);
        if (msp == NULL)
                goto out;
        memset(msp, 0, sizeof(*msp));

        msp->eth_base = ioremap(res->start, res->end - res->start + 1);
        if (msp->eth_base == NULL)
                goto out_free;

        spin_lock_init(&msp->phy_lock);
        msp->t_clk = (pd != NULL && pd->t_clk != 0) ? pd->t_clk : 133000000;

        platform_set_drvdata(pdev, msp);

        /*
         * (Re-)program MBUS remapping windows if we are asked to.
         */
        if (pd != NULL && pd->dram != NULL)
                mv643xx_eth_conf_mbus_windows(msp, pd->dram);

        return 0;

out_free:
        kfree(msp);
out:
        return ret;
}

static int mv643xx_eth_shared_remove(struct platform_device *pdev)
{
        struct mv643xx_shared_private *msp = platform_get_drvdata(pdev);

        iounmap(msp->eth_base);
        kfree(msp);

        return 0;
}

static void mv643xx_eth_shutdown(struct platform_device *pdev)
{
        struct net_device *dev = platform_get_drvdata(pdev);
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;

        /* Mask all interrupts on ethernet port */
        wrl(mp, INTERRUPT_MASK_REG(port_num), 0);
        rdl(mp, INTERRUPT_MASK_REG(port_num));

        eth_port_reset(mp);
}

static struct platform_driver mv643xx_eth_driver = {
        .probe = mv643xx_eth_probe,
        .remove = mv643xx_eth_remove,
        .shutdown = mv643xx_eth_shutdown,
        .driver = {
                .name = MV643XX_ETH_NAME,
                .owner  = THIS_MODULE,
        },
};

static struct platform_driver mv643xx_eth_shared_driver = {
        .probe = mv643xx_eth_shared_probe,
        .remove = mv643xx_eth_shared_remove,
        .driver = {
                .name = MV643XX_ETH_SHARED_NAME,
                .owner  = THIS_MODULE,
        },
};

/*
 * mv643xx_init_module
 *
 * Registers the network drivers into the Linux kernel
 *
 * Input :      N/A
 *
 * Output :     N/A
 */
static int __init mv643xx_init_module(void)
{
        int rc;

        rc = platform_driver_register(&mv643xx_eth_shared_driver);
        if (!rc) {
                rc = platform_driver_register(&mv643xx_eth_driver);
                if (rc)
                        platform_driver_unregister(&mv643xx_eth_shared_driver);
        }
        return rc;
}

/*
 * mv643xx_cleanup_module
 *
 * Registers the network drivers into the Linux kernel
 *
 * Input :      N/A
 *
 * Output :     N/A
 */
static void __exit mv643xx_cleanup_module(void)
{
        platform_driver_unregister(&mv643xx_eth_driver);
        platform_driver_unregister(&mv643xx_eth_shared_driver);
}

module_init(mv643xx_init_module);
module_exit(mv643xx_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_AUTHOR(  "Rabeeh Khoury, Assaf Hoffman, Matthew Dharm, Manish Lachwani"
                " and Dale Farnsworth");
MODULE_DESCRIPTION("Ethernet driver for Marvell MV643XX");
MODULE_ALIAS("platform:" MV643XX_ETH_NAME);
MODULE_ALIAS("platform:" MV643XX_ETH_SHARED_NAME);

/*
 * The second part is the low level driver of the gigE ethernet ports.
 */

/*
 * Marvell's Gigabit Ethernet controller low level driver
 *
 * DESCRIPTION:
 *      This file introduce low level API to Marvell's Gigabit Ethernet
 *              controller. This Gigabit Ethernet Controller driver API controls
 *              1) Operations (i.e. port init, start, reset etc').
 *              2) Data flow (i.e. port send, receive etc').
 *              Each Gigabit Ethernet port is controlled via
 *              struct mv643xx_private.
 *              This struct includes user configuration information as well as
 *              driver internal data needed for its operations.
 *
 *              Supported Features:
 *              - This low level driver is OS independent. Allocating memory for
 *                the descriptor rings and buffers are not within the scope of
 *                this driver.
 *              - The user is free from Rx/Tx queue managing.
 *              - This low level driver introduce functionality API that enable
 *                the to operate Marvell's Gigabit Ethernet Controller in a
 *                convenient way.
 *              - Simple Gigabit Ethernet port operation API.
 *              - Simple Gigabit Ethernet port data flow API.
 *              - Data flow and operation API support per queue functionality.
 *              - Support cached descriptors for better performance.
 *              - Enable access to all four DRAM banks and internal SRAM memory
 *                spaces.
 *              - PHY access and control API.
 *              - Port control register configuration API.
 *              - Full control over Unicast and Multicast MAC configurations.
 *
 *              Operation flow:
 *
 *              Initialization phase
 *              This phase complete the initialization of the the
 *              mv643xx_private struct.
 *              User information regarding port configuration has to be set
 *              prior to calling the port initialization routine.
 *
 *              In this phase any port Tx/Rx activity is halted, MIB counters
 *              are cleared, PHY address is set according to user parameter and
 *              access to DRAM and internal SRAM memory spaces.
 *
 *              Driver ring initialization
 *              Allocating memory for the descriptor rings and buffers is not
 *              within the scope of this driver. Thus, the user is required to
 *              allocate memory for the descriptors ring and buffers. Those
 *              memory parameters are used by the Rx and Tx ring initialization
 *              routines in order to curve the descriptor linked list in a form
 *              of a ring.
 *              Note: Pay special attention to alignment issues when using
 *              cached descriptors/buffers. In this phase the driver store
 *              information in the mv643xx_private struct regarding each queue
 *              ring.
 *
 *              Driver start
 *              This phase prepares the Ethernet port for Rx and Tx activity.
 *              It uses the information stored in the mv643xx_private struct to
 *              initialize the various port registers.
 *
 *              Data flow:
 *              All packet references to/from the driver are done using
 *              struct pkt_info.
 *              This struct is a unified struct used with Rx and Tx operations.
 *              This way the user is not required to be familiar with neither
 *              Tx nor Rx descriptors structures.
 *              The driver's descriptors rings are management by indexes.
 *              Those indexes controls the ring resources and used to indicate
 *              a SW resource error:
 *              'current'
 *              This index points to the current available resource for use. For
 *              example in Rx process this index will point to the descriptor
 *              that will be passed to the user upon calling the receive
 *              routine.  In Tx process, this index will point to the descriptor
 *              that will be assigned with the user packet info and transmitted.
 *              'used'
 *              This index points to the descriptor that need to restore its
 *              resources. For example in Rx process, using the Rx buffer return
 *              API will attach the buffer returned in packet info to the
 *              descriptor pointed by 'used'. In Tx process, using the Tx
 *              descriptor return will merely return the user packet info with
 *              the command status of the transmitted buffer pointed by the
 *              'used' index. Nevertheless, it is essential to use this routine
 *              to update the 'used' index.
 *              'first'
 *              This index supports Tx Scatter-Gather. It points to the first
 *              descriptor of a packet assembled of multiple buffers. For
 *              example when in middle of Such packet we have a Tx resource
 *              error the 'curr' index get the value of 'first' to indicate
 *              that the ring returned to its state before trying to transmit
 *              this packet.
 *
 *              Receive operation:
 *              The eth_port_receive API set the packet information struct,
 *              passed by the caller, with received information from the
 *              'current' SDMA descriptor.
 *              It is the user responsibility to return this resource back
 *              to the Rx descriptor ring to enable the reuse of this source.
 *              Return Rx resource is done using the eth_rx_return_buff API.
 *
 *      Prior to calling the initialization routine eth_port_init() the user
 *      must set the following fields under mv643xx_private struct:
 *      port_num                User Ethernet port number.
 *      port_config             User port configuration value.
 *      port_config_extend      User port config extend value.
 *      port_sdma_config        User port SDMA config value.
 *      port_serial_control     User port serial control value.
 *
 *              This driver data flow is done using the struct pkt_info which
 *              is a unified struct for Rx and Tx operations:
 *
 *              byte_cnt        Tx/Rx descriptor buffer byte count.
 *              l4i_chk         CPU provided TCP Checksum. For Tx operation
 *                              only.
 *              cmd_sts         Tx/Rx descriptor command status.
 *              buf_ptr         Tx/Rx descriptor buffer pointer.
 *              return_info     Tx/Rx user resource return information.
 */

/* Ethernet Port routines */
static void eth_port_set_filter_table_entry(struct mv643xx_private *mp,
                                            int table, unsigned char entry);

/*
 * eth_port_init - Initialize the Ethernet port driver
 *
 * DESCRIPTION:
 *      This function prepares the ethernet port to start its activity:
 *      1) Completes the ethernet port driver struct initialization toward port
 *              start routine.
 *      2) Resets the device to a quiescent state in case of warm reboot.
 *      3) Enable SDMA access to all four DRAM banks as well as internal SRAM.
 *      4) Clean MAC tables. The reset status of those tables is unknown.
 *      5) Set PHY address.
 *      Note: Call this routine prior to eth_port_start routine and after
 *      setting user values in the user fields of Ethernet port control
 *      struct.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet port control struct
 *
 * OUTPUT:
 *      See description.
 *
 * RETURN:
 *      None.
 */
static void eth_port_init(struct mv643xx_private *mp)
{
        mp->rx_resource_err = 0;

        eth_port_reset(mp);

        eth_port_init_mac_tables(mp);
}

/*
 * eth_port_start - Start the Ethernet port activity.
 *
 * DESCRIPTION:
 *      This routine prepares the Ethernet port for Rx and Tx activity:
 *       1. Initialize Tx and Rx Current Descriptor Pointer for each queue that
 *          has been initialized a descriptor's ring (using
 *          ether_init_tx_desc_ring for Tx and ether_init_rx_desc_ring for Rx)
 *       2. Initialize and enable the Ethernet configuration port by writing to
 *          the port's configuration and command registers.
 *       3. Initialize and enable the SDMA by writing to the SDMA's
 *          configuration and command registers.  After completing these steps,
 *          the ethernet port SDMA can starts to perform Rx and Tx activities.
 *
 *      Note: Each Rx and Tx queue descriptor's list must be initialized prior
 *      to calling this function (use ether_init_tx_desc_ring for Tx queues
 *      and ether_init_rx_desc_ring for Rx queues).
 *
 * INPUT:
 *      dev - a pointer to the required interface
 *
 * OUTPUT:
 *      Ethernet port is ready to receive and transmit.
 *
 * RETURN:
 *      None.
 */
static void eth_port_start(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;
        int tx_curr_desc, rx_curr_desc;
        u32 pscr;
        struct ethtool_cmd ethtool_cmd;

        /* Assignment of Tx CTRP of given queue */
        tx_curr_desc = mp->tx_curr_desc_q;
        wrl(mp, TX_CURRENT_QUEUE_DESC_PTR_0(port_num),
                (u32)((struct eth_tx_desc *)mp->tx_desc_dma + tx_curr_desc));

        /* Assignment of Rx CRDP of given queue */
        rx_curr_desc = mp->rx_curr_desc_q;
        wrl(mp, RX_CURRENT_QUEUE_DESC_PTR_0(port_num),
                (u32)((struct eth_rx_desc *)mp->rx_desc_dma + rx_curr_desc));

        /* Add the assigned Ethernet address to the port's address table */
        eth_port_uc_addr_set(mp, dev->dev_addr);

        /* Assign port configuration and command. */
        wrl(mp, PORT_CONFIG_REG(port_num),
                          PORT_CONFIG_DEFAULT_VALUE);

        wrl(mp, PORT_CONFIG_EXTEND_REG(port_num),
                          PORT_CONFIG_EXTEND_DEFAULT_VALUE);

        pscr = rdl(mp, PORT_SERIAL_CONTROL_REG(port_num));

        pscr &= ~(SERIAL_PORT_ENABLE | FORCE_LINK_PASS);
        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), pscr);

        pscr |= DISABLE_AUTO_NEG_FOR_FLOW_CTRL |
                DISABLE_AUTO_NEG_SPEED_GMII    |
                DISABLE_AUTO_NEG_FOR_DUPLX     |
                DO_NOT_FORCE_LINK_FAIL     |
                SERIAL_PORT_CONTROL_RESERVED;

        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), pscr);

        pscr |= SERIAL_PORT_ENABLE;
        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), pscr);

        /* Assign port SDMA configuration */
        wrl(mp, SDMA_CONFIG_REG(port_num),
                          PORT_SDMA_CONFIG_DEFAULT_VALUE);

        /* Enable port Rx. */
        mv643xx_eth_port_enable_rx(mp, ETH_RX_QUEUES_ENABLED);

        /* Disable port bandwidth limits by clearing MTU register */
        wrl(mp, MAXIMUM_TRANSMIT_UNIT(port_num), 0);

        /* save phy settings across reset */
        mv643xx_get_settings(dev, &ethtool_cmd);
        ethernet_phy_reset(mp);
        mv643xx_set_settings(dev, &ethtool_cmd);
}

/*
 * eth_port_uc_addr_set - Write a MAC address into the port's hw registers
 */
static void eth_port_uc_addr_set(struct mv643xx_private *mp,
                                 unsigned char *p_addr)
{
        unsigned int port_num = mp->port_num;
        unsigned int mac_h;
        unsigned int mac_l;
        int table;

        mac_l = (p_addr[4] << 8) | (p_addr[5]);
        mac_h = (p_addr[0] << 24) | (p_addr[1] << 16) | (p_addr[2] << 8) |
                                                        (p_addr[3] << 0);

        wrl(mp, MAC_ADDR_LOW(port_num), mac_l);
        wrl(mp, MAC_ADDR_HIGH(port_num), mac_h);

        /* Accept frames with this address */
        table = DA_FILTER_UNICAST_TABLE_BASE(port_num);
        eth_port_set_filter_table_entry(mp, table, p_addr[5] & 0x0f);
}

/*
 * eth_port_uc_addr_get - Read the MAC address from the port's hw registers
 */
static void eth_port_uc_addr_get(struct mv643xx_private *mp,
                                 unsigned char *p_addr)
{
        unsigned int port_num = mp->port_num;
        unsigned int mac_h;
        unsigned int mac_l;

        mac_h = rdl(mp, MAC_ADDR_HIGH(port_num));
        mac_l = rdl(mp, MAC_ADDR_LOW(port_num));

        p_addr[0] = (mac_h >> 24) & 0xff;
        p_addr[1] = (mac_h >> 16) & 0xff;
        p_addr[2] = (mac_h >> 8) & 0xff;
        p_addr[3] = mac_h & 0xff;
        p_addr[4] = (mac_l >> 8) & 0xff;
        p_addr[5] = mac_l & 0xff;
}

/*
 * The entries in each table are indexed by a hash of a packet's MAC
 * address.  One bit in each entry determines whether the packet is
 * accepted.  There are 4 entries (each 8 bits wide) in each register
 * of the table.  The bits in each entry are defined as follows:
 *      0       Accept=1, Drop=0
 *      3-1     Queue                   (ETH_Q0=0)
 *      7-4     Reserved = 0;
 */
static void eth_port_set_filter_table_entry(struct mv643xx_private *mp,
                                            int table, unsigned char entry)
{
        unsigned int table_reg;
        unsigned int tbl_offset;
        unsigned int reg_offset;

        tbl_offset = (entry / 4) * 4;   /* Register offset of DA table entry */
        reg_offset = entry % 4;         /* Entry offset within the register */

        /* Set "accepts frame bit" at specified table entry */
        table_reg = rdl(mp, table + tbl_offset);
        table_reg |= 0x01 << (8 * reg_offset);
        wrl(mp, table + tbl_offset, table_reg);
}

/*
 * eth_port_mc_addr - Multicast address settings.
 *
 * The MV device supports multicast using two tables:
 * 1) Special Multicast Table for MAC addresses of the form
 *    0x01-00-5E-00-00-XX (where XX is between 0x00 and 0x_FF).
 *    The MAC DA[7:0] bits are used as a pointer to the Special Multicast
 *    Table entries in the DA-Filter table.
 * 2) Other Multicast Table for multicast of another type. A CRC-8bit
 *    is used as an index to the Other Multicast Table entries in the
 *    DA-Filter table.  This function calculates the CRC-8bit value.
 * In either case, eth_port_set_filter_table_entry() is then called
 * to set to set the actual table entry.
 */
static void eth_port_mc_addr(struct mv643xx_private *mp, unsigned char *p_addr)
{
        unsigned int port_num = mp->port_num;
        unsigned int mac_h;
        unsigned int mac_l;
        unsigned char crc_result = 0;
        int table;
        int mac_array[48];
        int crc[8];
        int i;

        if ((p_addr[0] == 0x01) && (p_addr[1] == 0x00) &&
            (p_addr[2] == 0x5E) && (p_addr[3] == 0x00) && (p_addr[4] == 0x00)) {
                table = DA_FILTER_SPECIAL_MULTICAST_TABLE_BASE(port_num);
                eth_port_set_filter_table_entry(mp, table, p_addr[5]);
                return;
        }

        /* Calculate CRC-8 out of the given address */
        mac_h = (p_addr[0] << 8) | (p_addr[1]);
        mac_l = (p_addr[2] << 24) | (p_addr[3] << 16) |
                        (p_addr[4] << 8) | (p_addr[5] << 0);

        for (i = 0; i < 32; i++)
                mac_array[i] = (mac_l >> i) & 0x1;
        for (i = 32; i < 48; i++)
                mac_array[i] = (mac_h >> (i - 32)) & 0x1;

        crc[0] = mac_array[45] ^ mac_array[43] ^ mac_array[40] ^ mac_array[39] ^
                 mac_array[35] ^ mac_array[34] ^ mac_array[31] ^ mac_array[30] ^
                 mac_array[28] ^ mac_array[23] ^ mac_array[21] ^ mac_array[19] ^
                 mac_array[18] ^ mac_array[16] ^ mac_array[14] ^ mac_array[12] ^
                 mac_array[8]  ^ mac_array[7]  ^ mac_array[6]  ^ mac_array[0];

        crc[1] = mac_array[46] ^ mac_array[45] ^ mac_array[44] ^ mac_array[43] ^
                 mac_array[41] ^ mac_array[39] ^ mac_array[36] ^ mac_array[34] ^
                 mac_array[32] ^ mac_array[30] ^ mac_array[29] ^ mac_array[28] ^
                 mac_array[24] ^ mac_array[23] ^ mac_array[22] ^ mac_array[21] ^
                 mac_array[20] ^ mac_array[18] ^ mac_array[17] ^ mac_array[16] ^
                 mac_array[15] ^ mac_array[14] ^ mac_array[13] ^ mac_array[12] ^
                 mac_array[9]  ^ mac_array[6]  ^ mac_array[1]  ^ mac_array[0];

        crc[2] = mac_array[47] ^ mac_array[46] ^ mac_array[44] ^ mac_array[43] ^
                 mac_array[42] ^ mac_array[39] ^ mac_array[37] ^ mac_array[34] ^
                 mac_array[33] ^ mac_array[29] ^ mac_array[28] ^ mac_array[25] ^
                 mac_array[24] ^ mac_array[22] ^ mac_array[17] ^ mac_array[15] ^
                 mac_array[13] ^ mac_array[12] ^ mac_array[10] ^ mac_array[8]  ^
                 mac_array[6]  ^ mac_array[2]  ^ mac_array[1]  ^ mac_array[0];

        crc[3] = mac_array[47] ^ mac_array[45] ^ mac_array[44] ^ mac_array[43] ^
                 mac_array[40] ^ mac_array[38] ^ mac_array[35] ^ mac_array[34] ^
                 mac_array[30] ^ mac_array[29] ^ mac_array[26] ^ mac_array[25] ^
                 mac_array[23] ^ mac_array[18] ^ mac_array[16] ^ mac_array[14] ^
                 mac_array[13] ^ mac_array[11] ^ mac_array[9]  ^ mac_array[7]  ^
                 mac_array[3]  ^ mac_array[2]  ^ mac_array[1];

        crc[4] = mac_array[46] ^ mac_array[45] ^ mac_array[44] ^ mac_array[41] ^
                 mac_array[39] ^ mac_array[36] ^ mac_array[35] ^ mac_array[31] ^
                 mac_array[30] ^ mac_array[27] ^ mac_array[26] ^ mac_array[24] ^
                 mac_array[19] ^ mac_array[17] ^ mac_array[15] ^ mac_array[14] ^
                 mac_array[12] ^ mac_array[10] ^ mac_array[8]  ^ mac_array[4]  ^
                 mac_array[3]  ^ mac_array[2];

        crc[5] = mac_array[47] ^ mac_array[46] ^ mac_array[45] ^ mac_array[42] ^
                 mac_array[40] ^ mac_array[37] ^ mac_array[36] ^ mac_array[32] ^
                 mac_array[31] ^ mac_array[28] ^ mac_array[27] ^ mac_array[25] ^
                 mac_array[20] ^ mac_array[18] ^ mac_array[16] ^ mac_array[15] ^
                 mac_array[13] ^ mac_array[11] ^ mac_array[9]  ^ mac_array[5]  ^
                 mac_array[4]  ^ mac_array[3];

        crc[6] = mac_array[47] ^ mac_array[46] ^ mac_array[43] ^ mac_array[41] ^
                 mac_array[38] ^ mac_array[37] ^ mac_array[33] ^ mac_array[32] ^
                 mac_array[29] ^ mac_array[28] ^ mac_array[26] ^ mac_array[21] ^
                 mac_array[19] ^ mac_array[17] ^ mac_array[16] ^ mac_array[14] ^
                 mac_array[12] ^ mac_array[10] ^ mac_array[6]  ^ mac_array[5]  ^
                 mac_array[4];

        crc[7] = mac_array[47] ^ mac_array[44] ^ mac_array[42] ^ mac_array[39] ^
                 mac_array[38] ^ mac_array[34] ^ mac_array[33] ^ mac_array[30] ^
                 mac_array[29] ^ mac_array[27] ^ mac_array[22] ^ mac_array[20] ^
                 mac_array[18] ^ mac_array[17] ^ mac_array[15] ^ mac_array[13] ^
                 mac_array[11] ^ mac_array[7]  ^ mac_array[6]  ^ mac_array[5];

        for (i = 0; i < 8; i++)
                crc_result = crc_result | (crc[i] << i);

        table = DA_FILTER_OTHER_MULTICAST_TABLE_BASE(port_num);
        eth_port_set_filter_table_entry(mp, table, crc_result);
}

/*
 * Set the entire multicast list based on dev->mc_list.
 */
static void eth_port_set_multicast_list(struct net_device *dev)
{

        struct dev_mc_list      *mc_list;
        int                     i;
        int                     table_index;
        struct mv643xx_private  *mp = netdev_priv(dev);
        unsigned int            eth_port_num = mp->port_num;

        /* If the device is in promiscuous mode or in all multicast mode,
         * we will fully populate both multicast tables with accept.
         * This is guaranteed to yield a match on all multicast addresses...
         */
        if ((dev->flags & IFF_PROMISC) || (dev->flags & IFF_ALLMULTI)) {
                for (table_index = 0; table_index <= 0xFC; table_index += 4) {
                        /* Set all entries in DA filter special multicast
                         * table (Ex_dFSMT)
                         * Set for ETH_Q0 for now
                         * Bits
                         * 0      Accept=1, Drop=0
                         * 3-1  Queue    ETH_Q0=0
                         * 7-4  Reserved = 0;
                         */
                        wrl(mp, DA_FILTER_SPECIAL_MULTICAST_TABLE_BASE(eth_port_num) + table_index, 0x01010101);

                        /* Set all entries in DA filter other multicast
                         * table (Ex_dFOMT)
                         * Set for ETH_Q0 for now
                         * Bits
                         * 0      Accept=1, Drop=0
                         * 3-1  Queue    ETH_Q0=0
                         * 7-4  Reserved = 0;
                         */
                        wrl(mp, DA_FILTER_OTHER_MULTICAST_TABLE_BASE(eth_port_num) + table_index, 0x01010101);
                }
                return;
        }

        /* We will clear out multicast tables every time we get the list.
         * Then add the entire new list...
         */
        for (table_index = 0; table_index <= 0xFC; table_index += 4) {
                /* Clear DA filter special multicast table (Ex_dFSMT) */
                wrl(mp, DA_FILTER_SPECIAL_MULTICAST_TABLE_BASE
                                (eth_port_num) + table_index, 0);

                /* Clear DA filter other multicast table (Ex_dFOMT) */
                wrl(mp, DA_FILTER_OTHER_MULTICAST_TABLE_BASE
                                (eth_port_num) + table_index, 0);
        }

        /* Get pointer to net_device multicast list and add each one... */
        for (i = 0, mc_list = dev->mc_list;
                        (i < 256) && (mc_list != NULL) && (i < dev->mc_count);
                        i++, mc_list = mc_list->next)
                if (mc_list->dmi_addrlen == 6)
                        eth_port_mc_addr(mp, mc_list->dmi_addr);
}

/*
 * eth_port_init_mac_tables - Clear all entrance in the UC, SMC and OMC tables
 *
 * DESCRIPTION:
 *      Go through all the DA filter tables (Unicast, Special Multicast &
 *      Other Multicast) and set each entry to 0.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *
 * OUTPUT:
 *      Multicast and Unicast packets are rejected.
 *
 * RETURN:
 *      None.
 */
static void eth_port_init_mac_tables(struct mv643xx_private *mp)
{
        unsigned int port_num = mp->port_num;
        int table_index;

        /* Clear DA filter unicast table (Ex_dFUT) */
        for (table_index = 0; table_index <= 0xC; table_index += 4)
                wrl(mp, DA_FILTER_UNICAST_TABLE_BASE(port_num) +
                                        table_index, 0);

        for (table_index = 0; table_index <= 0xFC; table_index += 4) {
                /* Clear DA filter special multicast table (Ex_dFSMT) */
                wrl(mp, DA_FILTER_SPECIAL_MULTICAST_TABLE_BASE(port_num) +
                                        table_index, 0);
                /* Clear DA filter other multicast table (Ex_dFOMT) */
                wrl(mp, DA_FILTER_OTHER_MULTICAST_TABLE_BASE(port_num) +
                                        table_index, 0);
        }
}

/*
 * eth_clear_mib_counters - Clear all MIB counters
 *
 * DESCRIPTION:
 *      This function clears all MIB counters of a specific ethernet port.
 *      A read from the MIB counter will reset the counter.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *
 * OUTPUT:
 *      After reading all MIB counters, the counters resets.
 *
 * RETURN:
 *      MIB counter value.
 *
 */
static void eth_clear_mib_counters(struct mv643xx_private *mp)
{
        unsigned int port_num = mp->port_num;
        int i;

        /* Perform dummy reads from MIB counters */
        for (i = ETH_MIB_GOOD_OCTETS_RECEIVED_LOW; i < ETH_MIB_LATE_COLLISION;
                                                                        i += 4)
                rdl(mp, MIB_COUNTERS_BASE(port_num) + i);
}

static inline u32 read_mib(struct mv643xx_private *mp, int offset)
{
        return rdl(mp, MIB_COUNTERS_BASE(mp->port_num) + offset);
}

static void eth_update_mib_counters(struct mv643xx_private *mp)
{
        struct mv643xx_mib_counters *p = &mp->mib_counters;
        int offset;

        p->good_octets_received +=
                read_mib(mp, ETH_MIB_GOOD_OCTETS_RECEIVED_LOW);
        p->good_octets_received +=
                (u64)read_mib(mp, ETH_MIB_GOOD_OCTETS_RECEIVED_HIGH) << 32;

        for (offset = ETH_MIB_BAD_OCTETS_RECEIVED;
                        offset <= ETH_MIB_FRAMES_1024_TO_MAX_OCTETS;
                        offset += 4)
                *(u32 *)((char *)p + offset) += read_mib(mp, offset);

        p->good_octets_sent += read_mib(mp, ETH_MIB_GOOD_OCTETS_SENT_LOW);
        p->good_octets_sent +=
                (u64)read_mib(mp, ETH_MIB_GOOD_OCTETS_SENT_HIGH) << 32;

        for (offset = ETH_MIB_GOOD_FRAMES_SENT;
                        offset <= ETH_MIB_LATE_COLLISION;
                        offset += 4)
                *(u32 *)((char *)p + offset) += read_mib(mp, offset);
}

/*
 * ethernet_phy_detect - Detect whether a phy is present
 *
 * DESCRIPTION:
 *      This function tests whether there is a PHY present on
 *      the specified port.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *
 * OUTPUT:
 *      None
 *
 * RETURN:
 *      0 on success
 *      -ENODEV on failure
 *
 */
static int ethernet_phy_detect(struct mv643xx_private *mp)
{
        unsigned int phy_reg_data0;
        int auto_neg;

        eth_port_read_smi_reg(mp, 0, &phy_reg_data0);
        auto_neg = phy_reg_data0 & 0x1000;
        phy_reg_data0 ^= 0x1000;        /* invert auto_neg */
        eth_port_write_smi_reg(mp, 0, phy_reg_data0);

        eth_port_read_smi_reg(mp, 0, &phy_reg_data0);
        if ((phy_reg_data0 & 0x1000) == auto_neg)
                return -ENODEV;                         /* change didn't take */

        phy_reg_data0 ^= 0x1000;
        eth_port_write_smi_reg(mp, 0, phy_reg_data0);
        return 0;
}

/*
 * ethernet_phy_get - Get the ethernet port PHY address.
 *
 * DESCRIPTION:
 *      This routine returns the given ethernet port PHY address.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *
 * OUTPUT:
 *      None.
 *
 * RETURN:
 *      PHY address.
 *
 */
static int ethernet_phy_get(struct mv643xx_private *mp)
{
        unsigned int reg_data;

        reg_data = rdl(mp, PHY_ADDR_REG);

        return ((reg_data >> (5 * mp->port_num)) & 0x1f);
}

/*
 * ethernet_phy_set - Set the ethernet port PHY address.
 *
 * DESCRIPTION:
 *      This routine sets the given ethernet port PHY address.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *      int             phy_addr        PHY address.
 *
 * OUTPUT:
 *      None.
 *
 * RETURN:
 *      None.
 *
 */
static void ethernet_phy_set(struct mv643xx_private *mp, int phy_addr)
{
        u32 reg_data;
        int addr_shift = 5 * mp->port_num;

        reg_data = rdl(mp, PHY_ADDR_REG);
        reg_data &= ~(0x1f << addr_shift);
        reg_data |= (phy_addr & 0x1f) << addr_shift;
        wrl(mp, PHY_ADDR_REG, reg_data);
}

/*
 * ethernet_phy_reset - Reset Ethernet port PHY.
 *
 * DESCRIPTION:
 *      This routine utilizes the SMI interface to reset the ethernet port PHY.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *
 * OUTPUT:
 *      The PHY is reset.
 *
 * RETURN:
 *      None.
 *
 */
static void ethernet_phy_reset(struct mv643xx_private *mp)
{
        unsigned int phy_reg_data;

        /* Reset the PHY */
        eth_port_read_smi_reg(mp, 0, &phy_reg_data);
        phy_reg_data |= 0x8000; /* Set bit 15 to reset the PHY */
        eth_port_write_smi_reg(mp, 0, phy_reg_data);

        /* wait for PHY to come out of reset */
        do {
                udelay(1);
                eth_port_read_smi_reg(mp, 0, &phy_reg_data);
        } while (phy_reg_data & 0x8000);
}

static void mv643xx_eth_port_enable_tx(struct mv643xx_private *mp,
                                        unsigned int queues)
{
        wrl(mp, TRANSMIT_QUEUE_COMMAND_REG(mp->port_num), queues);
}

static void mv643xx_eth_port_enable_rx(struct mv643xx_private *mp,
                                        unsigned int queues)
{
        wrl(mp, RECEIVE_QUEUE_COMMAND_REG(mp->port_num), queues);
}

static unsigned int mv643xx_eth_port_disable_tx(struct mv643xx_private *mp)
{
        unsigned int port_num = mp->port_num;
        u32 queues;

        /* Stop Tx port activity. Check port Tx activity. */
        queues = rdl(mp, TRANSMIT_QUEUE_COMMAND_REG(port_num)) & 0xFF;
        if (queues) {
                /* Issue stop command for active queues only */
                wrl(mp, TRANSMIT_QUEUE_COMMAND_REG(port_num), (queues << 8));

                /* Wait for all Tx activity to terminate. */
                /* Check port cause register that all Tx queues are stopped */
                while (rdl(mp, TRANSMIT_QUEUE_COMMAND_REG(port_num)) & 0xFF)
                        udelay(PHY_WAIT_MICRO_SECONDS);

                /* Wait for Tx FIFO to empty */
                while (rdl(mp, PORT_STATUS_REG(port_num)) &
                                                        ETH_PORT_TX_FIFO_EMPTY)
                        udelay(PHY_WAIT_MICRO_SECONDS);
        }

        return queues;
}

static unsigned int mv643xx_eth_port_disable_rx(struct mv643xx_private *mp)
{
        unsigned int port_num = mp->port_num;
        u32 queues;

        /* Stop Rx port activity. Check port Rx activity. */
        queues = rdl(mp, RECEIVE_QUEUE_COMMAND_REG(port_num)) & 0xFF;
        if (queues) {
                /* Issue stop command for active queues only */
                wrl(mp, RECEIVE_QUEUE_COMMAND_REG(port_num), (queues << 8));

                /* Wait for all Rx activity to terminate. */
                /* Check port cause register that all Rx queues are stopped */
                while (rdl(mp, RECEIVE_QUEUE_COMMAND_REG(port_num)) & 0xFF)
                        udelay(PHY_WAIT_MICRO_SECONDS);
        }

        return queues;
}

/*
 * eth_port_reset - Reset Ethernet port
 *
 * DESCRIPTION:
 *      This routine resets the chip by aborting any SDMA engine activity and
 *      clearing the MIB counters. The Receiver and the Transmit unit are in
 *      idle state after this command is performed and the port is disabled.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *
 * OUTPUT:
 *      Channel activity is halted.
 *
 * RETURN:
 *      None.
 *
 */
static void eth_port_reset(struct mv643xx_private *mp)
{
        unsigned int port_num = mp->port_num;
        unsigned int reg_data;

        mv643xx_eth_port_disable_tx(mp);
        mv643xx_eth_port_disable_rx(mp);

        /* Clear all MIB counters */
        eth_clear_mib_counters(mp);

        /* Reset the Enable bit in the Configuration Register */
        reg_data = rdl(mp, PORT_SERIAL_CONTROL_REG(port_num));
        reg_data &= ~(SERIAL_PORT_ENABLE                |
                        DO_NOT_FORCE_LINK_FAIL  |
                        FORCE_LINK_PASS);
        wrl(mp, PORT_SERIAL_CONTROL_REG(port_num), reg_data);
}


/*
 * eth_port_read_smi_reg - Read PHY registers
 *
 * DESCRIPTION:
 *      This routine utilize the SMI interface to interact with the PHY in
 *      order to perform PHY register read.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *      unsigned int    phy_reg         PHY register address offset.
 *      unsigned int    *value          Register value buffer.
 *
 * OUTPUT:
 *      Write the value of a specified PHY register into given buffer.
 *
 * RETURN:
 *      false if the PHY is busy or read data is not in valid state.
 *      true otherwise.
 *
 */
static void eth_port_read_smi_reg(struct mv643xx_private *mp,
                                unsigned int phy_reg, unsigned int *value)
{
        void __iomem *smi_reg = mp->shared_smi->eth_base + SMI_REG;
        int phy_addr = ethernet_phy_get(mp);
        unsigned long flags;
        int i;

        /* the SMI register is a shared resource */
        spin_lock_irqsave(&mp->shared_smi->phy_lock, flags);

        /* wait for the SMI register to become available */
        for (i = 0; readl(smi_reg) & ETH_SMI_BUSY; i++) {
                if (i == PHY_WAIT_ITERATIONS) {
                        printk("%s: PHY busy timeout\n", mp->dev->name);
                        goto out;
                }
                udelay(PHY_WAIT_MICRO_SECONDS);
        }

        writel((phy_addr << 16) | (phy_reg << 21) | ETH_SMI_OPCODE_READ,
                smi_reg);

        /* now wait for the data to be valid */
        for (i = 0; !(readl(smi_reg) & ETH_SMI_READ_VALID); i++) {
                if (i == PHY_WAIT_ITERATIONS) {
                        printk("%s: PHY read timeout\n", mp->dev->name);
                        goto out;
                }
                udelay(PHY_WAIT_MICRO_SECONDS);
        }

        *value = readl(smi_reg) & 0xffff;
out:
        spin_unlock_irqrestore(&mp->shared_smi->phy_lock, flags);
}

/*
 * eth_port_write_smi_reg - Write to PHY registers
 *
 * DESCRIPTION:
 *      This routine utilize the SMI interface to interact with the PHY in
 *      order to perform writes to PHY registers.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port.
 *      unsigned int    phy_reg         PHY register address offset.
 *      unsigned int    value           Register value.
 *
 * OUTPUT:
 *      Write the given value to the specified PHY register.
 *
 * RETURN:
 *      false if the PHY is busy.
 *      true otherwise.
 *
 */
static void eth_port_write_smi_reg(struct mv643xx_private *mp,
                                   unsigned int phy_reg, unsigned int value)
{
        void __iomem *smi_reg = mp->shared_smi->eth_base + SMI_REG;
        int phy_addr = ethernet_phy_get(mp);
        unsigned long flags;
        int i;

        /* the SMI register is a shared resource */
        spin_lock_irqsave(&mp->shared_smi->phy_lock, flags);

        /* wait for the SMI register to become available */
        for (i = 0; readl(smi_reg) & ETH_SMI_BUSY; i++) {
                if (i == PHY_WAIT_ITERATIONS) {
                        printk("%s: PHY busy timeout\n", mp->dev->name);
                        goto out;
                }
                udelay(PHY_WAIT_MICRO_SECONDS);
        }

        writel((phy_addr << 16) | (phy_reg << 21) |
                ETH_SMI_OPCODE_WRITE | (value & 0xffff), smi_reg);
out:
        spin_unlock_irqrestore(&mp->shared_smi->phy_lock, flags);
}

/*
 * Wrappers for MII support library.
 */
static int mv643xx_mdio_read(struct net_device *dev, int phy_id, int location)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        int val;

        eth_port_read_smi_reg(mp, location, &val);
        return val;
}

static void mv643xx_mdio_write(struct net_device *dev, int phy_id, int location, int val)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        eth_port_write_smi_reg(mp, location, val);
}

/*
 * eth_port_receive - Get received information from Rx ring.
 *
 * DESCRIPTION:
 *      This routine returns the received data to the caller. There is no
 *      data copying during routine operation. All information is returned
 *      using pointer to packet information struct passed from the caller.
 *      If the routine exhausts Rx ring resources then the resource error flag
 *      is set.
 *
 * INPUT:
 *      struct mv643xx_private  *mp             Ethernet Port Control srtuct.
 *      struct pkt_info         *p_pkt_info     User packet buffer.
 *
 * OUTPUT:
 *      Rx ring current and used indexes are updated.
 *
 * RETURN:
 *      ETH_ERROR in case the routine can not access Rx desc ring.
 *      ETH_QUEUE_FULL if Rx ring resources are exhausted.
 *      ETH_END_OF_JOB if there is no received data.
 *      ETH_OK otherwise.
 */
static ETH_FUNC_RET_STATUS eth_port_receive(struct mv643xx_private *mp,
                                                struct pkt_info *p_pkt_info)
{
        int rx_next_curr_desc, rx_curr_desc, rx_used_desc;
        volatile struct eth_rx_desc *p_rx_desc;
        unsigned int command_status;
        unsigned long flags;

        /* Do not process Rx ring in case of Rx ring resource error */
        if (mp->rx_resource_err)
                return ETH_QUEUE_FULL;

        spin_lock_irqsave(&mp->lock, flags);

        /* Get the Rx Desc ring 'curr and 'used' indexes */
        rx_curr_desc = mp->rx_curr_desc_q;
        rx_used_desc = mp->rx_used_desc_q;

        p_rx_desc = &mp->p_rx_desc_area[rx_curr_desc];

        /* The following parameters are used to save readings from memory */
        command_status = p_rx_desc->cmd_sts;
        rmb();

        /* Nothing to receive... */
        if (command_status & (ETH_BUFFER_OWNED_BY_DMA)) {
                spin_unlock_irqrestore(&mp->lock, flags);
                return ETH_END_OF_JOB;
        }

        p_pkt_info->byte_cnt = (p_rx_desc->byte_cnt) - RX_BUF_OFFSET;
        p_pkt_info->cmd_sts = command_status;
        p_pkt_info->buf_ptr = (p_rx_desc->buf_ptr) + RX_BUF_OFFSET;
        p_pkt_info->return_info = mp->rx_skb[rx_curr_desc];
        p_pkt_info->l4i_chk = p_rx_desc->buf_size;

        /*
         * Clean the return info field to indicate that the
         * packet has been moved to the upper layers
         */
        mp->rx_skb[rx_curr_desc] = NULL;

        /* Update current index in data structure */
        rx_next_curr_desc = (rx_curr_desc + 1) % mp->rx_ring_size;
        mp->rx_curr_desc_q = rx_next_curr_desc;

        /* Rx descriptors exhausted. Set the Rx ring resource error flag */
        if (rx_next_curr_desc == rx_used_desc)
                mp->rx_resource_err = 1;

        spin_unlock_irqrestore(&mp->lock, flags);

        return ETH_OK;
}

/*
 * eth_rx_return_buff - Returns a Rx buffer back to the Rx ring.
 *
 * DESCRIPTION:
 *      This routine returns a Rx buffer back to the Rx ring. It retrieves the
 *      next 'used' descriptor and attached the returned buffer to it.
 *      In case the Rx ring was in "resource error" condition, where there are
 *      no available Rx resources, the function resets the resource error flag.
 *
 * INPUT:
 *      struct mv643xx_private  *mp             Ethernet Port Control srtuct.
 *      struct pkt_info         *p_pkt_info     Information on returned buffer.
 *
 * OUTPUT:
 *      New available Rx resource in Rx descriptor ring.
 *
 * RETURN:
 *      ETH_ERROR in case the routine can not access Rx desc ring.
 *      ETH_OK otherwise.
 */
static ETH_FUNC_RET_STATUS eth_rx_return_buff(struct mv643xx_private *mp,
                                                struct pkt_info *p_pkt_info)
{
        int used_rx_desc;       /* Where to return Rx resource */
        volatile struct eth_rx_desc *p_used_rx_desc;
        unsigned long flags;

        spin_lock_irqsave(&mp->lock, flags);

        /* Get 'used' Rx descriptor */
        used_rx_desc = mp->rx_used_desc_q;
        p_used_rx_desc = &mp->p_rx_desc_area[used_rx_desc];

        p_used_rx_desc->buf_ptr = p_pkt_info->buf_ptr;
        p_used_rx_desc->buf_size = p_pkt_info->byte_cnt;
        mp->rx_skb[used_rx_desc] = p_pkt_info->return_info;

        /* Flush the write pipe */

        /* Return the descriptor to DMA ownership */
        wmb();
        p_used_rx_desc->cmd_sts =
                        ETH_BUFFER_OWNED_BY_DMA | ETH_RX_ENABLE_INTERRUPT;
        wmb();

        /* Move the used descriptor pointer to the next descriptor */
        mp->rx_used_desc_q = (used_rx_desc + 1) % mp->rx_ring_size;

        /* Any Rx return cancels the Rx resource error status */
        mp->rx_resource_err = 0;

        spin_unlock_irqrestore(&mp->lock, flags);

        return ETH_OK;
}

/************* Begin ethtool support *************************/

struct mv643xx_stats {
        char stat_string[ETH_GSTRING_LEN];
        int sizeof_stat;
        int stat_offset;
};

#define MV643XX_STAT(m) FIELD_SIZEOF(struct mv643xx_private, m), \
                                        offsetof(struct mv643xx_private, m)

static const struct mv643xx_stats mv643xx_gstrings_stats[] = {
        { "rx_packets", MV643XX_STAT(stats.rx_packets) },
        { "tx_packets", MV643XX_STAT(stats.tx_packets) },
        { "rx_bytes", MV643XX_STAT(stats.rx_bytes) },
        { "tx_bytes", MV643XX_STAT(stats.tx_bytes) },
        { "rx_errors", MV643XX_STAT(stats.rx_errors) },
        { "tx_errors", MV643XX_STAT(stats.tx_errors) },
        { "rx_dropped", MV643XX_STAT(stats.rx_dropped) },
        { "tx_dropped", MV643XX_STAT(stats.tx_dropped) },
        { "good_octets_received", MV643XX_STAT(mib_counters.good_octets_received) },
        { "bad_octets_received", MV643XX_STAT(mib_counters.bad_octets_received) },
        { "internal_mac_transmit_err", MV643XX_STAT(mib_counters.internal_mac_transmit_err) },
        { "good_frames_received", MV643XX_STAT(mib_counters.good_frames_received) },
        { "bad_frames_received", MV643XX_STAT(mib_counters.bad_frames_received) },
        { "broadcast_frames_received", MV643XX_STAT(mib_counters.broadcast_frames_received) },
        { "multicast_frames_received", MV643XX_STAT(mib_counters.multicast_frames_received) },
        { "frames_64_octets", MV643XX_STAT(mib_counters.frames_64_octets) },
        { "frames_65_to_127_octets", MV643XX_STAT(mib_counters.frames_65_to_127_octets) },
        { "frames_128_to_255_octets", MV643XX_STAT(mib_counters.frames_128_to_255_octets) },
        { "frames_256_to_511_octets", MV643XX_STAT(mib_counters.frames_256_to_511_octets) },
        { "frames_512_to_1023_octets", MV643XX_STAT(mib_counters.frames_512_to_1023_octets) },
        { "frames_1024_to_max_octets", MV643XX_STAT(mib_counters.frames_1024_to_max_octets) },
        { "good_octets_sent", MV643XX_STAT(mib_counters.good_octets_sent) },
        { "good_frames_sent", MV643XX_STAT(mib_counters.good_frames_sent) },
        { "excessive_collision", MV643XX_STAT(mib_counters.excessive_collision) },
        { "multicast_frames_sent", MV643XX_STAT(mib_counters.multicast_frames_sent) },
        { "broadcast_frames_sent", MV643XX_STAT(mib_counters.broadcast_frames_sent) },
        { "unrec_mac_control_received", MV643XX_STAT(mib_counters.unrec_mac_control_received) },
        { "fc_sent", MV643XX_STAT(mib_counters.fc_sent) },
        { "good_fc_received", MV643XX_STAT(mib_counters.good_fc_received) },
        { "bad_fc_received", MV643XX_STAT(mib_counters.bad_fc_received) },
        { "undersize_received", MV643XX_STAT(mib_counters.undersize_received) },
        { "fragments_received", MV643XX_STAT(mib_counters.fragments_received) },
        { "oversize_received", MV643XX_STAT(mib_counters.oversize_received) },
        { "jabber_received", MV643XX_STAT(mib_counters.jabber_received) },
        { "mac_receive_error", MV643XX_STAT(mib_counters.mac_receive_error) },
        { "bad_crc_event", MV643XX_STAT(mib_counters.bad_crc_event) },
        { "collision", MV643XX_STAT(mib_counters.collision) },
        { "late_collision", MV643XX_STAT(mib_counters.late_collision) },
};

#define MV643XX_STATS_LEN       ARRAY_SIZE(mv643xx_gstrings_stats)

static void mv643xx_get_drvinfo(struct net_device *netdev,
                                struct ethtool_drvinfo *drvinfo)
{
        strncpy(drvinfo->driver,  mv643xx_driver_name, 32);
        strncpy(drvinfo->version, mv643xx_driver_version, 32);
        strncpy(drvinfo->fw_version, "N/A", 32);
        strncpy(drvinfo->bus_info, "mv643xx", 32);
        drvinfo->n_stats = MV643XX_STATS_LEN;
}

static int mv643xx_get_sset_count(struct net_device *netdev, int sset)
{
        switch (sset) {
        case ETH_SS_STATS:
                return MV643XX_STATS_LEN;
        default:
                return -EOPNOTSUPP;
        }
}

static void mv643xx_get_ethtool_stats(struct net_device *netdev,
                                struct ethtool_stats *stats, uint64_t *data)
{
        struct mv643xx_private *mp = netdev->priv;
        int i;

        eth_update_mib_counters(mp);

        for (i = 0; i < MV643XX_STATS_LEN; i++) {
                char *p = (char *)mp+mv643xx_gstrings_stats[i].stat_offset;
                data[i] = (mv643xx_gstrings_stats[i].sizeof_stat ==
                        sizeof(uint64_t)) ? *(uint64_t *)p : *(uint32_t *)p;
        }
}

static void mv643xx_get_strings(struct net_device *netdev, uint32_t stringset,
                                uint8_t *data)
{
        int i;

        switch(stringset) {
        case ETH_SS_STATS:
                for (i=0; i < MV643XX_STATS_LEN; i++) {
                        memcpy(data + i * ETH_GSTRING_LEN,
                                        mv643xx_gstrings_stats[i].stat_string,
                                        ETH_GSTRING_LEN);
                }
                break;
        }
}

static u32 mv643xx_eth_get_link(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        return mii_link_ok(&mp->mii);
}

static int mv643xx_eth_nway_restart(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        return mii_nway_restart(&mp->mii);
}

static int mv643xx_eth_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        return generic_mii_ioctl(&mp->mii, if_mii(ifr), cmd, NULL);
}

static const struct ethtool_ops mv643xx_ethtool_ops = {
        .get_settings           = mv643xx_get_settings,
        .set_settings           = mv643xx_set_settings,
        .get_drvinfo            = mv643xx_get_drvinfo,
        .get_link               = mv643xx_eth_get_link,
        .set_sg                 = ethtool_op_set_sg,
        .get_sset_count         = mv643xx_get_sset_count,
        .get_ethtool_stats      = mv643xx_get_ethtool_stats,
        .get_strings            = mv643xx_get_strings,
        .nway_reset             = mv643xx_eth_nway_restart,
};

/************* End ethtool support *************************/