// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 1999 - 2018 Intel Corporation. */

#include <linux/pci.h>
#include <linux/delay.h>
#include "ixgbe.h"
#include "ixgbe_mbx.h"

/**
 *  ixgbe_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 ixgbe_read_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;

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

        if (!mbx->ops)
                return IXGBE_ERR_MBX;

        return mbx->ops->read(hw, msg, size, mbx_id);
}

/**
 *  ixgbe_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 ixgbe_write_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;

        if (size > mbx->size)
                return IXGBE_ERR_MBX;

        if (!mbx->ops)
                return IXGBE_ERR_MBX;

        return mbx->ops->write(hw, msg, size, mbx_id);
}

/**
 *  ixgbe_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 ixgbe_check_for_msg(struct ixgbe_hw *hw, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;

        if (!mbx->ops)
                return IXGBE_ERR_MBX;

        return mbx->ops->check_for_msg(hw, mbx_id);
}

/**
 *  ixgbe_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 ixgbe_check_for_ack(struct ixgbe_hw *hw, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;

        if (!mbx->ops)
                return IXGBE_ERR_MBX;

        return mbx->ops->check_for_ack(hw, mbx_id);
}

/**
 *  ixgbe_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 ixgbe_check_for_rst(struct ixgbe_hw *hw, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;

        if (!mbx->ops)
                return IXGBE_ERR_MBX;

        return mbx->ops->check_for_rst(hw, mbx_id);
}

/**
 *  ixgbe_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 ixgbe_poll_for_msg(struct ixgbe_hw *hw, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;
        int countdown = mbx->timeout;

        if (!countdown || !mbx->ops)
                return IXGBE_ERR_MBX;

        while (mbx->ops->check_for_msg(hw, mbx_id)) {
                countdown--;
                if (!countdown)
                        return IXGBE_ERR_MBX;
                udelay(mbx->usec_delay);
        }

        return 0;
}

/**
 *  ixgbe_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 ixgbe_poll_for_ack(struct ixgbe_hw *hw, u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;
        int countdown = mbx->timeout;

        if (!countdown || !mbx->ops)
                return IXGBE_ERR_MBX;

        while (mbx->ops->check_for_ack(hw, mbx_id)) {
                countdown--;
                if (!countdown)
                        return IXGBE_ERR_MBX;
                udelay(mbx->usec_delay);
        }

        return 0;
}

/**
 *  ixgbe_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 ixgbe_read_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size,
                                 u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;
        s32 ret_val;

        if (!mbx->ops)
                return IXGBE_ERR_MBX;

        ret_val = ixgbe_poll_for_msg(hw, mbx_id);
        if (ret_val)
                return ret_val;

        /* if ack received read message */
        return mbx->ops->read(hw, msg, size, mbx_id);
}

/**
 *  ixgbe_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 ixgbe_write_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size,
                           u16 mbx_id)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;
        s32 ret_val;

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

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

        /* if msg sent wait until we receive an ack */
        return ixgbe_poll_for_ack(hw, mbx_id);
}

static s32 ixgbe_check_for_bit_pf(struct ixgbe_hw *hw, u32 mask, s32 index)
{
        u32 mbvficr = IXGBE_READ_REG(hw, IXGBE_MBVFICR(index));

        if (mbvficr & mask) {
                IXGBE_WRITE_REG(hw, IXGBE_MBVFICR(index), mask);
                return 0;
        }

        return IXGBE_ERR_MBX;
}

/**
 *  ixgbe_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 ixgbe_check_for_msg_pf(struct ixgbe_hw *hw, u16 vf_number)
{
        s32 index = IXGBE_MBVFICR_INDEX(vf_number);
        u32 vf_bit = vf_number % 16;

        if (!ixgbe_check_for_bit_pf(hw, IXGBE_MBVFICR_VFREQ_VF1 << vf_bit,
                                    index)) {
                hw->mbx.stats.reqs++;
                return 0;
        }

        return IXGBE_ERR_MBX;
}

/**
 *  ixgbe_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 ixgbe_check_for_ack_pf(struct ixgbe_hw *hw, u16 vf_number)
{
        s32 index = IXGBE_MBVFICR_INDEX(vf_number);
        u32 vf_bit = vf_number % 16;

        if (!ixgbe_check_for_bit_pf(hw, IXGBE_MBVFICR_VFACK_VF1 << vf_bit,
                                    index)) {
                hw->mbx.stats.acks++;
                return 0;
        }

        return IXGBE_ERR_MBX;
}

/**
 *  ixgbe_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 ixgbe_check_for_rst_pf(struct ixgbe_hw *hw, u16 vf_number)
{
        u32 reg_offset = (vf_number < 32) ? 0 : 1;
        u32 vf_shift = vf_number % 32;
        u32 vflre = 0;

        switch (hw->mac.type) {
        case ixgbe_mac_82599EB:
                vflre = IXGBE_READ_REG(hw, IXGBE_VFLRE(reg_offset));
                break;
        case ixgbe_mac_X540:
        case ixgbe_mac_X550:
        case ixgbe_mac_X550EM_x:
        case ixgbe_mac_x550em_a:
                vflre = IXGBE_READ_REG(hw, IXGBE_VFLREC(reg_offset));
                break;
        default:
                break;
        }

        if (vflre & BIT(vf_shift)) {
                IXGBE_WRITE_REG(hw, IXGBE_VFLREC(reg_offset), BIT(vf_shift));
                hw->mbx.stats.rsts++;
                return 0;
        }

        return IXGBE_ERR_MBX;
}

/**
 *  ixgbe_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 ixgbe_obtain_mbx_lock_pf(struct ixgbe_hw *hw, u16 vf_number)
{
        u32 p2v_mailbox;

        /* Take ownership of the buffer */
        IXGBE_WRITE_REG(hw, IXGBE_PFMAILBOX(vf_number), IXGBE_PFMAILBOX_PFU);

        /* reserve mailbox for vf use */
        p2v_mailbox = IXGBE_READ_REG(hw, IXGBE_PFMAILBOX(vf_number));
        if (p2v_mailbox & IXGBE_PFMAILBOX_PFU)
                return 0;

        return IXGBE_ERR_MBX;
}

/**
 *  ixgbe_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 ixgbe_write_mbx_pf(struct ixgbe_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 = ixgbe_obtain_mbx_lock_pf(hw, vf_number);
        if (ret_val)
                return ret_val;

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

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

        /* Interrupt VF to tell it a message has been sent and release buffer*/
        IXGBE_WRITE_REG(hw, IXGBE_PFMAILBOX(vf_number), IXGBE_PFMAILBOX_STS);

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

        return 0;
}

/**
 *  ixgbe_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
 *
 *  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 ixgbe_read_mbx_pf(struct ixgbe_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 = ixgbe_obtain_mbx_lock_pf(hw, vf_number);
        if (ret_val)
                return ret_val;

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

        /* Acknowledge the message and release buffer */
        IXGBE_WRITE_REG(hw, IXGBE_PFMAILBOX(vf_number), IXGBE_PFMAILBOX_ACK);

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

        return 0;
}

#ifdef CONFIG_PCI_IOV
/**
 *  ixgbe_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
 */
void ixgbe_init_mbx_params_pf(struct ixgbe_hw *hw)
{
        struct ixgbe_mbx_info *mbx = &hw->mbx;

        if (hw->mac.type != ixgbe_mac_82599EB &&
            hw->mac.type != ixgbe_mac_X550 &&
            hw->mac.type != ixgbe_mac_X550EM_x &&
            hw->mac.type != ixgbe_mac_x550em_a &&
            hw->mac.type != ixgbe_mac_X540)
                return;

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

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

        mbx->size = IXGBE_VFMAILBOX_SIZE;
}
#endif /* CONFIG_PCI_IOV */

const struct ixgbe_mbx_operations mbx_ops_generic = {
        .read                   = ixgbe_read_mbx_pf,
        .write                  = ixgbe_write_mbx_pf,
        .read_posted            = ixgbe_read_posted_mbx,
        .write_posted           = ixgbe_write_posted_mbx,
        .check_for_msg          = ixgbe_check_for_msg_pf,
        .check_for_ack          = ixgbe_check_for_ack_pf,
        .check_for_rst          = ixgbe_check_for_rst_pf,
};