// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2007 - 2018 Intel Corporation. */

#include "e1000_mbx.h"

/**
 *  igb_read_mbx - Reads a message from the mailbox
 *  @hw: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @mbx_id: id of mailbox to read
 *
 *  returns SUCCESS if it successfully read message from buffer
 **/
s32 igb_read_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id,
                 bool unlock)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        /* limit read to size of mailbox */
        if (size > mbx->size)
                size = mbx->size;

        if (mbx->ops.read)
                ret_val = mbx->ops.read(hw, msg, size, mbx_id, unlock);

        return ret_val;
}

/**
 *  igb_write_mbx - Write a message to the mailbox
 *  @hw: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @mbx_id: id of mailbox to write
 *
 *  returns SUCCESS if it successfully copied message into the buffer
 **/
s32 igb_write_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = 0;

        if (size > mbx->size)
                ret_val = -E1000_ERR_MBX;

        else if (mbx->ops.write)
                ret_val = mbx->ops.write(hw, msg, size, mbx_id);

        return ret_val;
}

/**
 *  igb_check_for_msg - checks to see if someone sent us mail
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns SUCCESS if the Status bit was found or else ERR_MBX
 **/
s32 igb_check_for_msg(struct e1000_hw *hw, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        if (mbx->ops.check_for_msg)
                ret_val = mbx->ops.check_for_msg(hw, mbx_id);

        return ret_val;
}

/**
 *  igb_check_for_ack - checks to see if someone sent us ACK
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns SUCCESS if the Status bit was found or else ERR_MBX
 **/
s32 igb_check_for_ack(struct e1000_hw *hw, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        if (mbx->ops.check_for_ack)
                ret_val = mbx->ops.check_for_ack(hw, mbx_id);

        return ret_val;
}

/**
 *  igb_check_for_rst - checks to see if other side has reset
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns SUCCESS if the Status bit was found or else ERR_MBX
 **/
s32 igb_check_for_rst(struct e1000_hw *hw, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        if (mbx->ops.check_for_rst)
                ret_val = mbx->ops.check_for_rst(hw, mbx_id);

        return ret_val;
}

/**
 *  igb_unlock_mbx - unlock the mailbox
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns SUCCESS if the mailbox was unlocked or else ERR_MBX
 **/
s32 igb_unlock_mbx(struct e1000_hw *hw, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        if (mbx->ops.unlock)
                ret_val = mbx->ops.unlock(hw, mbx_id);

        return ret_val;
}

/**
 *  igb_poll_for_msg - Wait for message notification
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to write
 *
 *  returns SUCCESS if it successfully received a message notification
 **/
static s32 igb_poll_for_msg(struct e1000_hw *hw, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        int countdown = mbx->timeout;

        if (!countdown || !mbx->ops.check_for_msg)
                goto out;

        while (countdown && mbx->ops.check_for_msg(hw, mbx_id)) {
                countdown--;
                if (!countdown)
                        break;
                udelay(mbx->usec_delay);
        }

        /* if we failed, all future posted messages fail until reset */
        if (!countdown)
                mbx->timeout = 0;
out:
        return countdown ? 0 : -E1000_ERR_MBX;
}

/**
 *  igb_poll_for_ack - Wait for message acknowledgement
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to write
 *
 *  returns SUCCESS if it successfully received a message acknowledgement
 **/
static s32 igb_poll_for_ack(struct e1000_hw *hw, u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        int countdown = mbx->timeout;

        if (!countdown || !mbx->ops.check_for_ack)
                goto out;

        while (countdown && mbx->ops.check_for_ack(hw, mbx_id)) {
                countdown--;
                if (!countdown)
                        break;
                udelay(mbx->usec_delay);
        }

        /* if we failed, all future posted messages fail until reset */
        if (!countdown)
                mbx->timeout = 0;
out:
        return countdown ? 0 : -E1000_ERR_MBX;
}

/**
 *  igb_read_posted_mbx - Wait for message notification and receive message
 *  @hw: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @mbx_id: id of mailbox to write
 *
 *  returns SUCCESS if it successfully received a message notification and
 *  copied it into the receive buffer.
 **/
static s32 igb_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
                               u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        if (!mbx->ops.read)
                goto out;

        ret_val = igb_poll_for_msg(hw, mbx_id);

        if (!ret_val)
                ret_val = mbx->ops.read(hw, msg, size, mbx_id, true);
out:
        return ret_val;
}

/**
 *  igb_write_posted_mbx - Write a message to the mailbox, wait for ack
 *  @hw: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @mbx_id: id of mailbox to write
 *
 *  returns SUCCESS if it successfully copied message into the buffer and
 *  received an ack to that message within delay * timeout period
 **/
static s32 igb_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
                                u16 mbx_id)
{
        struct e1000_mbx_info *mbx = &hw->mbx;
        s32 ret_val = -E1000_ERR_MBX;

        /* exit if either we can't write or there isn't a defined timeout */
        if (!mbx->ops.write || !mbx->timeout)
                goto out;

        /* send msg */
        ret_val = mbx->ops.write(hw, msg, size, mbx_id);

        /* if msg sent wait until we receive an ack */
        if (!ret_val)
                ret_val = igb_poll_for_ack(hw, mbx_id);
out:
        return ret_val;
}

static s32 igb_check_for_bit_pf(struct e1000_hw *hw, u32 mask)
{
        u32 mbvficr = rd32(E1000_MBVFICR);
        s32 ret_val = -E1000_ERR_MBX;

        if (mbvficr & mask) {
                ret_val = 0;
                wr32(E1000_MBVFICR, mask);
        }

        return ret_val;
}

/**
 *  igb_check_for_msg_pf - checks to see if the VF has sent mail
 *  @hw: pointer to the HW structure
 *  @vf_number: the VF index
 *
 *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
 **/
static s32 igb_check_for_msg_pf(struct e1000_hw *hw, u16 vf_number)
{
        s32 ret_val = -E1000_ERR_MBX;

        if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFREQ_VF1 << vf_number)) {
                ret_val = 0;
                hw->mbx.stats.reqs++;
        }

        return ret_val;
}

/**
 *  igb_check_for_ack_pf - checks to see if the VF has ACKed
 *  @hw: pointer to the HW structure
 *  @vf_number: the VF index
 *
 *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
 **/
static s32 igb_check_for_ack_pf(struct e1000_hw *hw, u16 vf_number)
{
        s32 ret_val = -E1000_ERR_MBX;

        if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFACK_VF1 << vf_number)) {
                ret_val = 0;
                hw->mbx.stats.acks++;
        }

        return ret_val;
}

/**
 *  igb_check_for_rst_pf - checks to see if the VF has reset
 *  @hw: pointer to the HW structure
 *  @vf_number: the VF index
 *
 *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
 **/
static s32 igb_check_for_rst_pf(struct e1000_hw *hw, u16 vf_number)
{
        u32 vflre = rd32(E1000_VFLRE);
        s32 ret_val = -E1000_ERR_MBX;

        if (vflre & BIT(vf_number)) {
                ret_val = 0;
                wr32(E1000_VFLRE, BIT(vf_number));
                hw->mbx.stats.rsts++;
        }

        return ret_val;
}

/**
 *  igb_obtain_mbx_lock_pf - obtain mailbox lock
 *  @hw: pointer to the HW structure
 *  @vf_number: the VF index
 *
 *  return SUCCESS if we obtained the mailbox lock
 **/
static s32 igb_obtain_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
{
        s32 ret_val = -E1000_ERR_MBX;
        u32 p2v_mailbox;
        int count = 10;

        do {
                /* Take ownership of the buffer */
                wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_PFU);

                /* reserve mailbox for vf use */
                p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
                if (p2v_mailbox & E1000_P2VMAILBOX_PFU) {
                        ret_val = 0;
                        break;
                }
                udelay(1000);
        } while (count-- > 0);

        return ret_val;
}

/**
 *  igb_release_mbx_lock_pf - release mailbox lock
 *  @hw: pointer to the HW structure
 *  @vf_number: the VF index
 *
 *  return SUCCESS if we released the mailbox lock
 **/
static s32 igb_release_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
{
        u32 p2v_mailbox;

        /* drop PF lock of mailbox, if set */
        p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
        if (p2v_mailbox & E1000_P2VMAILBOX_PFU)
                wr32(E1000_P2VMAILBOX(vf_number),
                     p2v_mailbox & ~E1000_P2VMAILBOX_PFU);

        return 0;
}

/**
 *  igb_write_mbx_pf - Places a message in the mailbox
 *  @hw: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @vf_number: the VF index
 *
 *  returns SUCCESS if it successfully copied message into the buffer
 **/
static s32 igb_write_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
                            u16 vf_number)
{
        s32 ret_val;
        u16 i;

        /* lock the mailbox to prevent pf/vf race condition */
        ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
        if (ret_val)
                goto out_no_write;

        /* flush msg and acks as we are overwriting the message buffer */
        igb_check_for_msg_pf(hw, vf_number);
        igb_check_for_ack_pf(hw, vf_number);

        /* copy the caller specified message to the mailbox memory buffer */
        for (i = 0; i < size; i++)
                array_wr32(E1000_VMBMEM(vf_number), i, msg[i]);

        /* Interrupt VF to tell it a message has been sent and release buffer*/
        wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_STS);

        /* update stats */
        hw->mbx.stats.msgs_tx++;

out_no_write:
        return ret_val;

}

/**
 *  igb_read_mbx_pf - Read a message from the mailbox
 *  @hw: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @vf_number: the VF index
 *  @unlock: unlock the mailbox when done?
 *
 *  This function copies a message from the mailbox buffer to the caller's
 *  memory buffer.  The presumption is that the caller knows that there was
 *  a message due to a VF request so no polling for message is needed.
 **/
static s32 igb_read_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
                           u16 vf_number, bool unlock)
{
        s32 ret_val;
        u16 i;

        /* lock the mailbox to prevent pf/vf race condition */
        ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
        if (ret_val)
                goto out_no_read;

        /* copy the message to the mailbox memory buffer */
        for (i = 0; i < size; i++)
                msg[i] = array_rd32(E1000_VMBMEM(vf_number), i);

        /* Acknowledge the message and release mailbox lock (or not) */
        if (unlock)
                wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_ACK);
        else
                wr32(E1000_P2VMAILBOX(vf_number),
                     E1000_P2VMAILBOX_ACK | E1000_P2VMAILBOX_PFU);

        /* update stats */
        hw->mbx.stats.msgs_rx++;

out_no_read:
        return ret_val;
}

/**
 *  e1000_init_mbx_params_pf - set initial values for pf mailbox
 *  @hw: pointer to the HW structure
 *
 *  Initializes the hw->mbx struct to correct values for pf mailbox
 */
s32 igb_init_mbx_params_pf(struct e1000_hw *hw)
{
        struct e1000_mbx_info *mbx = &hw->mbx;

        mbx->timeout = 0;
        mbx->usec_delay = 0;

        mbx->size = E1000_VFMAILBOX_SIZE;

        mbx->ops.read = igb_read_mbx_pf;
        mbx->ops.write = igb_write_mbx_pf;
        mbx->ops.read_posted = igb_read_posted_mbx;
        mbx->ops.write_posted = igb_write_posted_mbx;
        mbx->ops.check_for_msg = igb_check_for_msg_pf;
        mbx->ops.check_for_ack = igb_check_for_ack_pf;
        mbx->ops.check_for_rst = igb_check_for_rst_pf;
        mbx->ops.unlock = igb_release_mbx_lock_pf;

        mbx->stats.msgs_tx = 0;
        mbx->stats.msgs_rx = 0;
        mbx->stats.reqs = 0;
        mbx->stats.acks = 0;
        mbx->stats.rsts = 0;

        return 0;
}