// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2015 - 2025 Beijing WangXun Technology Co., Ltd. */

#include <linux/pci.h>
#include "wx_type.h"
#include "wx_mbx.h"

/**
 *  wx_obtain_mbx_lock_pf - obtain mailbox lock
 *  @wx: pointer to the HW structure
 *  @vf: the VF index
 *
 *  Return: return 0 on success and -EBUSY on failure
 **/
static int wx_obtain_mbx_lock_pf(struct wx *wx, u16 vf)
{
        int count = 5;
        u32 mailbox;

        while (count--) {
                /* Take ownership of the buffer */
                wr32(wx, WX_PXMAILBOX(vf), WX_PXMAILBOX_PFU);

                /* reserve mailbox for vf use */
                mailbox = rd32(wx, WX_PXMAILBOX(vf));
                if (mailbox & WX_PXMAILBOX_PFU)
                        return 0;
                else if (count)
                        udelay(10);
        }
        wx_err(wx, "Failed to obtain mailbox lock for PF%d", vf);

        return -EBUSY;
}

static int wx_check_for_bit_pf(struct wx *wx, u32 mask, int index)
{
        u32 mbvficr = rd32(wx, WX_MBVFICR(index));

        if (!(mbvficr & mask))
                return -EBUSY;
        wr32(wx, WX_MBVFICR(index), mask);

        return 0;
}

/**
 *  wx_check_for_ack_pf - checks to see if the VF has acked
 *  @wx: pointer to the HW structure
 *  @vf: the VF index
 *
 *  Return: return 0 if the VF has set the status bit or else -EBUSY
 **/
int wx_check_for_ack_pf(struct wx *wx, u16 vf)
{
        u32 index = vf / 16, vf_bit = vf % 16;

        return wx_check_for_bit_pf(wx,
                                   FIELD_PREP(WX_MBVFICR_VFACK_MASK,
                                              BIT(vf_bit)),
                                   index);
}

/**
 *  wx_check_for_msg_pf - checks to see if the VF has sent mail
 *  @wx: pointer to the HW structure
 *  @vf: the VF index
 *
 *  Return: return 0 if the VF has got req bit or else -EBUSY
 **/
int wx_check_for_msg_pf(struct wx *wx, u16 vf)
{
        u32 index = vf / 16, vf_bit = vf % 16;

        return wx_check_for_bit_pf(wx,
                                   FIELD_PREP(WX_MBVFICR_VFREQ_MASK,
                                              BIT(vf_bit)),
                                   index);
}

/**
 *  wx_write_mbx_pf - Places a message in the mailbox
 *  @wx: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @vf: the VF index
 *
 *  Return: return 0 on success and -EINVAL/-EBUSY on failure
 **/
int wx_write_mbx_pf(struct wx *wx, u32 *msg, u16 size, u16 vf)
{
        struct wx_mbx_info *mbx = &wx->mbx;
        int ret, i;

        /* mbx->size is up to 15 */
        if (size > mbx->size) {
                wx_err(wx, "Invalid mailbox message size %d", size);
                return -EINVAL;
        }

        /* lock the mailbox to prevent pf/vf race condition */
        ret = wx_obtain_mbx_lock_pf(wx, vf);
        if (ret)
                return ret;

        /* flush msg and acks as we are overwriting the message buffer */
        wx_check_for_msg_pf(wx, vf);
        wx_check_for_ack_pf(wx, vf);

        /* copy the caller specified message to the mailbox memory buffer */
        for (i = 0; i < size; i++)
                wr32a(wx, WX_PXMBMEM(vf), i, msg[i]);

        /* Interrupt VF to tell it a message has been sent and release buffer */
        /* set mirrored mailbox flags */
        wr32a(wx, WX_PXMBMEM(vf), WX_VXMAILBOX_SIZE, WX_PXMAILBOX_STS);
        wr32(wx, WX_PXMAILBOX(vf), WX_PXMAILBOX_STS);

        return 0;
}

/**
 *  wx_read_mbx_pf - Read a message from the mailbox
 *  @wx: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *  @vf: the VF index
 *
 *  Return: return 0 on success and -EBUSY on failure
 **/
int wx_read_mbx_pf(struct wx *wx, u32 *msg, u16 size, u16 vf)
{
        struct wx_mbx_info *mbx = &wx->mbx;
        int ret;
        u16 i;

        /* limit read to size of mailbox and mbx->size is up to 15 */
        if (size > mbx->size)
                size = mbx->size;

        /* lock the mailbox to prevent pf/vf race condition */
        ret = wx_obtain_mbx_lock_pf(wx, vf);
        if (ret)
                return ret;

        for (i = 0; i < size; i++)
                msg[i] = rd32a(wx, WX_PXMBMEM(vf), i);

        /* Acknowledge the message and release buffer */
        /* set mirrored mailbox flags */
        wr32a(wx, WX_PXMBMEM(vf), WX_VXMAILBOX_SIZE, WX_PXMAILBOX_ACK);
        wr32(wx, WX_PXMAILBOX(vf), WX_PXMAILBOX_ACK);

        return 0;
}

/**
 *  wx_check_for_rst_pf - checks to see if the VF has reset
 *  @wx: pointer to the HW structure
 *  @vf: the VF index
 *
 *  Return: return 0 on success and -EBUSY on failure
 **/
int wx_check_for_rst_pf(struct wx *wx, u16 vf)
{
        u32 reg_offset = WX_VF_REG_OFFSET(vf);
        u32 vf_shift = WX_VF_IND_SHIFT(vf);
        u32 vflre = 0;

        vflre = rd32(wx, WX_VFLRE(reg_offset));
        if (!(vflre & BIT(vf_shift)))
                return -EBUSY;
        wr32(wx, WX_VFLREC(reg_offset), BIT(vf_shift));

        return 0;
}

static u32 wx_read_v2p_mailbox(struct wx *wx)
{
        u32 mailbox = rd32(wx, WX_VXMAILBOX);

        mailbox |= wx->mbx.mailbox;
        wx->mbx.mailbox |= mailbox & WX_VXMAILBOX_R2C_BITS;

        return mailbox;
}

static u32 wx_mailbox_get_lock_vf(struct wx *wx)
{
        wr32(wx, WX_VXMAILBOX, WX_VXMAILBOX_VFU);
        return wx_read_v2p_mailbox(wx);
}

/**
 *  wx_obtain_mbx_lock_vf - obtain mailbox lock
 *  @wx: pointer to the HW structure
 *
 *  Return: return 0 on success and -EBUSY on failure
 **/
static int wx_obtain_mbx_lock_vf(struct wx *wx)
{
        int count = 5, ret;
        u32 mailbox;

        ret = readx_poll_timeout_atomic(wx_mailbox_get_lock_vf, wx, mailbox,
                                        (mailbox & WX_VXMAILBOX_VFU),
                                        1, count);
        if (ret)
                wx_err(wx, "Failed to obtain mailbox lock for VF.\n");

        return ret;
}

static int wx_check_for_bit_vf(struct wx *wx, u32 mask)
{
        u32 mailbox = wx_read_v2p_mailbox(wx);

        wx->mbx.mailbox &= ~mask;

        return (mailbox & mask ? 0 : -EBUSY);
}

/**
 *  wx_check_for_ack_vf - checks to see if the PF has ACK'd
 *  @wx: pointer to the HW structure
 *
 *  Return: return 0 if the PF has set the status bit or else -EBUSY
 **/
static int wx_check_for_ack_vf(struct wx *wx)
{
        /* read clear the pf ack bit */
        return wx_check_for_bit_vf(wx, WX_VXMAILBOX_PFACK);
}

/**
 *  wx_check_for_msg_vf - checks to see if the PF has sent mail
 *  @wx: pointer to the HW structure
 *
 *  Return: return 0 if the PF has got req bit or else -EBUSY
 **/
int wx_check_for_msg_vf(struct wx *wx)
{
        /* read clear the pf sts bit */
        return wx_check_for_bit_vf(wx, WX_VXMAILBOX_PFSTS);
}

/**
 *  wx_check_for_rst_vf - checks to see if the PF has reset
 *  @wx: pointer to the HW structure
 *
 *  Return: return 0 if the PF has set the reset done and -EBUSY on failure
 **/
int wx_check_for_rst_vf(struct wx *wx)
{
        /* read clear the pf reset done bit */
        return wx_check_for_bit_vf(wx,
                                   WX_VXMAILBOX_RSTD |
                                   WX_VXMAILBOX_RSTI);
}

/**
 *  wx_poll_for_msg - Wait for message notification
 *  @wx: pointer to the HW structure
 *
 *  Return: return 0 if the VF has successfully received a message notification
 **/
static int wx_poll_for_msg(struct wx *wx)
{
        struct wx_mbx_info *mbx = &wx->mbx;
        u32 val;

        return readx_poll_timeout_atomic(wx_check_for_msg_vf, wx, val,
                                         (val == 0), mbx->udelay, mbx->timeout);
}

/**
 *  wx_poll_for_ack - Wait for message acknowledgment
 *  @wx: pointer to the HW structure
 *
 *  Return: return 0 if the VF has successfully received a message ack
 **/
static int wx_poll_for_ack(struct wx *wx)
{
        struct wx_mbx_info *mbx = &wx->mbx;
        u32 val;

        return readx_poll_timeout_atomic(wx_check_for_ack_vf, wx, val,
                                         (val == 0), mbx->udelay, mbx->timeout);
}

/**
 *  wx_read_posted_mbx - Wait for message notification and receive message
 *  @wx: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *
 *  Return: returns 0 if it successfully received a message notification and
 *  copied it into the receive buffer.
 **/
int wx_read_posted_mbx(struct wx *wx, u32 *msg, u16 size)
{
        int ret;

        ret = wx_poll_for_msg(wx);
        /* if ack received read message, otherwise we timed out */
        if (ret)
                return ret;

        return wx_read_mbx_vf(wx, msg, size);
}

/**
 *  wx_write_posted_mbx - Write a message to the mailbox, wait for ack
 *  @wx: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *
 *  Return: returns 0 if it successfully copied message into the buffer and
 *  received an ack to that message within delay * timeout period
 **/
int wx_write_posted_mbx(struct wx *wx, u32 *msg, u16 size)
{
        int ret;

        /* send msg */
        ret = wx_write_mbx_vf(wx, msg, size);
        /* if msg sent wait until we receive an ack */
        if (ret)
                return ret;

        return wx_poll_for_ack(wx);
}

/**
 *  wx_write_mbx_vf - Write a message to the mailbox
 *  @wx: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *
 *  Return: returns 0 if it successfully copied message into the buffer
 **/
int wx_write_mbx_vf(struct wx *wx, u32 *msg, u16 size)
{
        struct wx_mbx_info *mbx = &wx->mbx;
        int ret, i;

        /* mbx->size is up to 15 */
        if (size > mbx->size) {
                wx_err(wx, "Invalid mailbox message size %d", size);
                return -EINVAL;
        }

        /* lock the mailbox to prevent pf/vf race condition */
        ret = wx_obtain_mbx_lock_vf(wx);
        if (ret)
                return ret;

        /* flush msg and acks as we are overwriting the message buffer */
        wx_check_for_msg_vf(wx);
        wx_check_for_ack_vf(wx);

        /* copy the caller specified message to the mailbox memory buffer */
        for (i = 0; i < size; i++)
                wr32a(wx, WX_VXMBMEM, i, msg[i]);

        /* Drop VFU and interrupt the PF to tell it a message has been sent */
        wr32(wx, WX_VXMAILBOX, WX_VXMAILBOX_REQ);

        return 0;
}

/**
 *  wx_read_mbx_vf - Reads a message from the inbox intended for vf
 *  @wx: pointer to the HW structure
 *  @msg: The message buffer
 *  @size: Length of buffer
 *
 *  Return: returns 0 if it successfully copied message into the buffer
 **/
int wx_read_mbx_vf(struct wx *wx, u32 *msg, u16 size)
{
        struct wx_mbx_info *mbx = &wx->mbx;
        int ret, i;

        /* limit read to size of mailbox and mbx->size is up to 15 */
        if (size > mbx->size)
                size = mbx->size;

        /* lock the mailbox to prevent pf/vf race condition */
        ret = wx_obtain_mbx_lock_vf(wx);
        if (ret)
                return ret;

        /* copy the message from the mailbox memory buffer */
        for (i = 0; i < size; i++)
                msg[i] = rd32a(wx, WX_VXMBMEM, i);

        /* Acknowledge receipt and release mailbox, then we're done */
        wr32(wx, WX_VXMAILBOX, WX_VXMAILBOX_ACK);

        return 0;
}

int wx_init_mbx_params_vf(struct wx *wx)
{
        wx->vfinfo = kzalloc_obj(struct vf_data_storage);
        if (!wx->vfinfo)
                return -ENOMEM;

        /* Initialize mailbox parameters */
        wx->mbx.size = WX_VXMAILBOX_SIZE;
        wx->mbx.mailbox = WX_VXMAILBOX;
        wx->mbx.udelay = 10;
        wx->mbx.timeout = 1000;

        return 0;
}
EXPORT_SYMBOL(wx_init_mbx_params_vf);