/* Intel PRO/1000 Linux driver
 * Copyright(c) 1999 - 2015 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * The full GNU General Public License is included in this distribution in
 * the file called "COPYING".
 *
 * Contact Information:
 * Linux NICS <linux.nics@intel.com>
 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 */

#include "e1000.h"

/**
 *  e1000_calculate_checksum - Calculate checksum for buffer
 *  @buffer: pointer to EEPROM
 *  @length: size of EEPROM to calculate a checksum for
 *
 *  Calculates the checksum for some buffer on a specified length.  The
 *  checksum calculated is returned.
 **/
static u8 e1000_calculate_checksum(u8 *buffer, u32 length)
{
        u32 i;
        u8 sum = 0;

        if (!buffer)
                return 0;

        for (i = 0; i < length; i++)
                sum += buffer[i];

        return (u8)(0 - sum);
}

/**
 *  e1000_mng_enable_host_if - Checks host interface is enabled
 *  @hw: pointer to the HW structure
 *
 *  Returns 0 upon success, else -E1000_ERR_HOST_INTERFACE_COMMAND
 *
 *  This function checks whether the HOST IF is enabled for command operation
 *  and also checks whether the previous command is completed.  It busy waits
 *  in case of previous command is not completed.
 **/
static s32 e1000_mng_enable_host_if(struct e1000_hw *hw)
{
        u32 hicr;
        u8 i;

        if (!hw->mac.arc_subsystem_valid) {
                e_dbg("ARC subsystem not valid.\n");
                return -E1000_ERR_HOST_INTERFACE_COMMAND;
        }

        /* Check that the host interface is enabled. */
        hicr = er32(HICR);
        if (!(hicr & E1000_HICR_EN)) {
                e_dbg("E1000_HOST_EN bit disabled.\n");
                return -E1000_ERR_HOST_INTERFACE_COMMAND;
        }
        /* check the previous command is completed */
        for (i = 0; i < E1000_MNG_DHCP_COMMAND_TIMEOUT; i++) {
                hicr = er32(HICR);
                if (!(hicr & E1000_HICR_C))
                        break;
                mdelay(1);
        }

        if (i == E1000_MNG_DHCP_COMMAND_TIMEOUT) {
                e_dbg("Previous command timeout failed.\n");
                return -E1000_ERR_HOST_INTERFACE_COMMAND;
        }

        return 0;
}

/**
 *  e1000e_check_mng_mode_generic - Generic check management mode
 *  @hw: pointer to the HW structure
 *
 *  Reads the firmware semaphore register and returns true (>0) if
 *  manageability is enabled, else false (0).
 **/
bool e1000e_check_mng_mode_generic(struct e1000_hw *hw)
{
        u32 fwsm = er32(FWSM);

        return (fwsm & E1000_FWSM_MODE_MASK) ==
            (E1000_MNG_IAMT_MODE << E1000_FWSM_MODE_SHIFT);
}

/**
 *  e1000e_enable_tx_pkt_filtering - Enable packet filtering on Tx
 *  @hw: pointer to the HW structure
 *
 *  Enables packet filtering on transmit packets if manageability is enabled
 *  and host interface is enabled.
 **/
bool e1000e_enable_tx_pkt_filtering(struct e1000_hw *hw)
{
        struct e1000_host_mng_dhcp_cookie *hdr = &hw->mng_cookie;
        u32 *buffer = (u32 *)&hw->mng_cookie;
        u32 offset;
        s32 ret_val, hdr_csum, csum;
        u8 i, len;

        hw->mac.tx_pkt_filtering = true;

        /* No manageability, no filtering */
        if (!hw->mac.ops.check_mng_mode(hw)) {
                hw->mac.tx_pkt_filtering = false;
                return hw->mac.tx_pkt_filtering;
        }

        /* If we can't read from the host interface for whatever
         * reason, disable filtering.
         */
        ret_val = e1000_mng_enable_host_if(hw);
        if (ret_val) {
                hw->mac.tx_pkt_filtering = false;
                return hw->mac.tx_pkt_filtering;
        }

        /* Read in the header.  Length and offset are in dwords. */
        len = E1000_MNG_DHCP_COOKIE_LENGTH >> 2;
        offset = E1000_MNG_DHCP_COOKIE_OFFSET >> 2;
        for (i = 0; i < len; i++)
                *(buffer + i) = E1000_READ_REG_ARRAY(hw, E1000_HOST_IF,
                                                     offset + i);
        hdr_csum = hdr->checksum;
        hdr->checksum = 0;
        csum = e1000_calculate_checksum((u8 *)hdr,
                                        E1000_MNG_DHCP_COOKIE_LENGTH);
        /* If either the checksums or signature don't match, then
         * the cookie area isn't considered valid, in which case we
         * take the safe route of assuming Tx filtering is enabled.
         */
        if ((hdr_csum != csum) || (hdr->signature != E1000_IAMT_SIGNATURE)) {
                hw->mac.tx_pkt_filtering = true;
                return hw->mac.tx_pkt_filtering;
        }

        /* Cookie area is valid, make the final check for filtering. */
        if (!(hdr->status & E1000_MNG_DHCP_COOKIE_STATUS_PARSING))
                hw->mac.tx_pkt_filtering = false;

        return hw->mac.tx_pkt_filtering;
}

/**
 *  e1000_mng_write_cmd_header - Writes manageability command header
 *  @hw: pointer to the HW structure
 *  @hdr: pointer to the host interface command header
 *
 *  Writes the command header after does the checksum calculation.
 **/
static s32 e1000_mng_write_cmd_header(struct e1000_hw *hw,
                                      struct e1000_host_mng_command_header *hdr)
{
        u16 i, length = sizeof(struct e1000_host_mng_command_header);

        /* Write the whole command header structure with new checksum. */

        hdr->checksum = e1000_calculate_checksum((u8 *)hdr, length);

        length >>= 2;
        /* Write the relevant command block into the ram area. */
        for (i = 0; i < length; i++) {
                E1000_WRITE_REG_ARRAY(hw, E1000_HOST_IF, i, *((u32 *)hdr + i));
                e1e_flush();
        }

        return 0;
}

/**
 *  e1000_mng_host_if_write - Write to the manageability host interface
 *  @hw: pointer to the HW structure
 *  @buffer: pointer to the host interface buffer
 *  @length: size of the buffer
 *  @offset: location in the buffer to write to
 *  @sum: sum of the data (not checksum)
 *
 *  This function writes the buffer content at the offset given on the host if.
 *  It also does alignment considerations to do the writes in most efficient
 *  way.  Also fills up the sum of the buffer in *buffer parameter.
 **/
static s32 e1000_mng_host_if_write(struct e1000_hw *hw, u8 *buffer,
                                   u16 length, u16 offset, u8 *sum)
{
        u8 *tmp;
        u8 *bufptr = buffer;
        u32 data = 0;
        u16 remaining, i, j, prev_bytes;

        /* sum = only sum of the data and it is not checksum */

        if (length == 0 || offset + length > E1000_HI_MAX_MNG_DATA_LENGTH)
                return -E1000_ERR_PARAM;

        tmp = (u8 *)&data;
        prev_bytes = offset & 0x3;
        offset >>= 2;

        if (prev_bytes) {
                data = E1000_READ_REG_ARRAY(hw, E1000_HOST_IF, offset);
                for (j = prev_bytes; j < sizeof(u32); j++) {
                        *(tmp + j) = *bufptr++;
                        *sum += *(tmp + j);
                }
                E1000_WRITE_REG_ARRAY(hw, E1000_HOST_IF, offset, data);
                length -= j - prev_bytes;
                offset++;
        }

        remaining = length & 0x3;
        length -= remaining;

        /* Calculate length in DWORDs */
        length >>= 2;

        /* The device driver writes the relevant command block into the
         * ram area.
         */
        for (i = 0; i < length; i++) {
                for (j = 0; j < sizeof(u32); j++) {
                        *(tmp + j) = *bufptr++;
                        *sum += *(tmp + j);
                }

                E1000_WRITE_REG_ARRAY(hw, E1000_HOST_IF, offset + i, data);
        }
        if (remaining) {
                for (j = 0; j < sizeof(u32); j++) {
                        if (j < remaining)
                                *(tmp + j) = *bufptr++;
                        else
                                *(tmp + j) = 0;

                        *sum += *(tmp + j);
                }
                E1000_WRITE_REG_ARRAY(hw, E1000_HOST_IF, offset + i, data);
        }

        return 0;
}

/**
 *  e1000e_mng_write_dhcp_info - Writes DHCP info to host interface
 *  @hw: pointer to the HW structure
 *  @buffer: pointer to the host interface
 *  @length: size of the buffer
 *
 *  Writes the DHCP information to the host interface.
 **/
s32 e1000e_mng_write_dhcp_info(struct e1000_hw *hw, u8 *buffer, u16 length)
{
        struct e1000_host_mng_command_header hdr;
        s32 ret_val;
        u32 hicr;

        hdr.command_id = E1000_MNG_DHCP_TX_PAYLOAD_CMD;
        hdr.command_length = length;
        hdr.reserved1 = 0;
        hdr.reserved2 = 0;
        hdr.checksum = 0;

        /* Enable the host interface */
        ret_val = e1000_mng_enable_host_if(hw);
        if (ret_val)
                return ret_val;

        /* Populate the host interface with the contents of "buffer". */
        ret_val = e1000_mng_host_if_write(hw, buffer, length,
                                          sizeof(hdr), &(hdr.checksum));
        if (ret_val)
                return ret_val;

        /* Write the manageability command header */
        ret_val = e1000_mng_write_cmd_header(hw, &hdr);
        if (ret_val)
                return ret_val;

        /* Tell the ARC a new command is pending. */
        hicr = er32(HICR);
        ew32(HICR, hicr | E1000_HICR_C);

        return 0;
}

/**
 *  e1000e_enable_mng_pass_thru - Check if management passthrough is needed
 *  @hw: pointer to the HW structure
 *
 *  Verifies the hardware needs to leave interface enabled so that frames can
 *  be directed to and from the management interface.
 **/
bool e1000e_enable_mng_pass_thru(struct e1000_hw *hw)
{
        u32 manc;
        u32 fwsm, factps;

        manc = er32(MANC);

        if (!(manc & E1000_MANC_RCV_TCO_EN))
                return false;

        if (hw->mac.has_fwsm) {
                fwsm = er32(FWSM);
                factps = er32(FACTPS);

                if (!(factps & E1000_FACTPS_MNGCG) &&
                    ((fwsm & E1000_FWSM_MODE_MASK) ==
                     (e1000_mng_mode_pt << E1000_FWSM_MODE_SHIFT)))
                        return true;
        } else if ((hw->mac.type == e1000_82574) ||
                   (hw->mac.type == e1000_82583)) {
                u16 data;
                s32 ret_val;

                factps = er32(FACTPS);
                ret_val = e1000_read_nvm(hw, NVM_INIT_CONTROL2_REG, 1, &data);
                if (ret_val)
                        return false;

                if (!(factps & E1000_FACTPS_MNGCG) &&
                    ((data & E1000_NVM_INIT_CTRL2_MNGM) ==
                     (e1000_mng_mode_pt << 13)))
                        return true;
        } else if ((manc & E1000_MANC_SMBUS_EN) &&
                   !(manc & E1000_MANC_ASF_EN)) {
                return true;
        }

        return false;
}