ixgbe_mbx.c

/*******************************************************************************

  Intel(R) 10GbE PCI Express Linux Network Driver
  Copyright(c) 1999 - 2017 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 "ixgbe_type.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 successfuly 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;
	s32 ret_val = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_read_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);

	return ret_val;
}

/**
 *  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;
	s32 ret_val = IXGBE_SUCCESS;

	DEBUGFUNC("ixgbe_write_mbx");

	if (size > mbx->size) {
		ret_val = IXGBE_ERR_MBX;
		ERROR_REPORT2(IXGBE_ERROR_ARGUMENT,
			     "Invalid mailbox message size %d", size);
	} else if (mbx->ops.write)
		ret_val = mbx->ops.write(hw, msg, size, mbx_id);

	return ret_val;
}

/**
 *  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;
	s32 ret_val = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_check_for_msg");

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

	return ret_val;
}

/**
 *  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;
	s32 ret_val = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_check_for_ack");

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

	return ret_val;
}

/**
 *  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;
	s32 ret_val = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_check_for_rst");

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

	return ret_val;
}

/**
 *  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;

	DEBUGFUNC("ixgbe_poll_for_msg");

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

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

	if (countdown == 0)
		ERROR_REPORT2(IXGBE_ERROR_POLLING,
			   "Polling for VF%d mailbox message timedout", mbx_id);

out:
	return countdown ? IXGBE_SUCCESS : IXGBE_ERR_MBX;
}

/**
 *  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;

	DEBUGFUNC("ixgbe_poll_for_ack");

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

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

	if (countdown == 0)
		ERROR_REPORT2(IXGBE_ERROR_POLLING,
			     "Polling for VF%d mailbox ack timedout", mbx_id);

out:
	return countdown ? IXGBE_SUCCESS : IXGBE_ERR_MBX;
}

/**
 *  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.
 **/
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 = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_read_posted_mbx");

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

	ret_val = ixgbe_poll_for_msg(hw, mbx_id);

	/* if ack received read message, otherwise we timed out */
	if (!ret_val)
		ret_val = mbx->ops.read(hw, msg, size, mbx_id);
out:
	return ret_val;
}

/**
 *  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
 **/
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 = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_write_posted_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 = ixgbe_poll_for_ack(hw, mbx_id);
out:
	return ret_val;
}

/**
 *  ixgbe_init_mbx_ops_generic - Initialize MB function pointers
 *  @hw: pointer to the HW structure
 *
 *  Setups up the mailbox read and write message function pointers
 **/
void ixgbe_init_mbx_ops_generic(struct ixgbe_hw *hw)
{
	struct ixgbe_mbx_info *mbx = &hw->mbx;

	mbx->ops.read_posted = ixgbe_read_posted_mbx;
	mbx->ops.write_posted = ixgbe_write_posted_mbx;
}

/**
 *  ixgbe_read_v2p_mailbox - read v2p mailbox
 *  @hw: pointer to the HW structure
 *
 *  This function is used to read the v2p mailbox without losing the read to
 *  clear status bits.
 **/
STATIC u32 ixgbe_read_v2p_mailbox(struct ixgbe_hw *hw)
{
	u32 v2p_mailbox = IXGBE_READ_REG(hw, IXGBE_VFMAILBOX);

	v2p_mailbox |= hw->mbx.v2p_mailbox;
	hw->mbx.v2p_mailbox |= v2p_mailbox & IXGBE_VFMAILBOX_R2C_BITS;

	return v2p_mailbox;
}

/**
 *  ixgbe_check_for_bit_vf - Determine if a status bit was set
 *  @hw: pointer to the HW structure
 *  @mask: bitmask for bits to be tested and cleared
 *
 *  This function is used to check for the read to clear bits within
 *  the V2P mailbox.
 **/
STATIC s32 ixgbe_check_for_bit_vf(struct ixgbe_hw *hw, u32 mask)
{
	u32 v2p_mailbox = ixgbe_read_v2p_mailbox(hw);
	s32 ret_val = IXGBE_ERR_MBX;

	if (v2p_mailbox & mask)
		ret_val = IXGBE_SUCCESS;

	hw->mbx.v2p_mailbox &= ~mask;

	return ret_val;
}

/**
 *  ixgbe_check_for_msg_vf - checks to see if the PF has sent mail
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns SUCCESS if the PF has set the Status bit or else ERR_MBX
 **/
STATIC s32 ixgbe_check_for_msg_vf(struct ixgbe_hw *hw, u16 mbx_id)
{
	s32 ret_val = IXGBE_ERR_MBX;

	UNREFERENCED_1PARAMETER(mbx_id);
	DEBUGFUNC("ixgbe_check_for_msg_vf");

	if (!ixgbe_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFSTS)) {
		ret_val = IXGBE_SUCCESS;
		hw->mbx.stats.reqs++;
	}

	return ret_val;
}

/**
 *  ixgbe_check_for_ack_vf - checks to see if the PF has ACK'd
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
 **/
STATIC s32 ixgbe_check_for_ack_vf(struct ixgbe_hw *hw, u16 mbx_id)
{
	s32 ret_val = IXGBE_ERR_MBX;

	UNREFERENCED_1PARAMETER(mbx_id);
	DEBUGFUNC("ixgbe_check_for_ack_vf");

	if (!ixgbe_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFACK)) {
		ret_val = IXGBE_SUCCESS;
		hw->mbx.stats.acks++;
	}

	return ret_val;
}

/**
 *  ixgbe_check_for_rst_vf - checks to see if the PF has reset
 *  @hw: pointer to the HW structure
 *  @mbx_id: id of mailbox to check
 *
 *  returns true if the PF has set the reset done bit or else false
 **/
STATIC s32 ixgbe_check_for_rst_vf(struct ixgbe_hw *hw, u16 mbx_id)
{
	s32 ret_val = IXGBE_ERR_MBX;

	UNREFERENCED_1PARAMETER(mbx_id);
	DEBUGFUNC("ixgbe_check_for_rst_vf");

	if (!ixgbe_check_for_bit_vf(hw, (IXGBE_VFMAILBOX_RSTD |
	    IXGBE_VFMAILBOX_RSTI))) {
		ret_val = IXGBE_SUCCESS;
		hw->mbx.stats.rsts++;
	}

	return ret_val;
}

/**
 *  ixgbe_obtain_mbx_lock_vf - obtain mailbox lock
 *  @hw: pointer to the HW structure
 *
 *  return SUCCESS if we obtained the mailbox lock
 **/
STATIC s32 ixgbe_obtain_mbx_lock_vf(struct ixgbe_hw *hw)
{
	s32 ret_val = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_obtain_mbx_lock_vf");

	/* Take ownership of the buffer */
	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_VFU);

	/* reserve mailbox for vf use */
	if (ixgbe_read_v2p_mailbox(hw) & IXGBE_VFMAILBOX_VFU)
		ret_val = IXGBE_SUCCESS;

	return ret_val;
}

/**
 *  ixgbe_write_mbx_vf - 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
 **/
STATIC s32 ixgbe_write_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size,
			      u16 mbx_id)
{
	s32 ret_val;
	u16 i;

	UNREFERENCED_1PARAMETER(mbx_id);

	DEBUGFUNC("ixgbe_write_mbx_vf");

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

	/* flush msg and acks as we are overwriting the message buffer */
	ixgbe_check_for_msg_vf(hw, 0);
	ixgbe_check_for_ack_vf(hw, 0);

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

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

	/* Drop VFU and interrupt the PF to tell it a message has been sent */
	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_REQ);

out_no_write:
	return ret_val;
}

/**
 *  ixgbe_read_mbx_vf - Reads a message from the inbox intended for vf
 *  @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 successfuly read message from buffer
 **/
STATIC s32 ixgbe_read_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size,
			     u16 mbx_id)
{
	s32 ret_val = IXGBE_SUCCESS;
	u16 i;

	DEBUGFUNC("ixgbe_read_mbx_vf");
	UNREFERENCED_1PARAMETER(mbx_id);

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

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

	/* Acknowledge receipt and release mailbox, then we're done */
	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_ACK);

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

out_no_read:
	return ret_val;
}

/**
 *  ixgbe_init_mbx_params_vf - set initial values for vf mailbox
 *  @hw: pointer to the HW structure
 *
 *  Initializes the hw->mbx struct to correct values for vf mailbox
 */
void ixgbe_init_mbx_params_vf(struct ixgbe_hw *hw)
{
	struct ixgbe_mbx_info *mbx = &hw->mbx;

	/* start mailbox as timed out and let the reset_hw call set the timeout
	 * value to begin communications */
	mbx->timeout = 0;
	mbx->usec_delay = IXGBE_VF_MBX_INIT_DELAY;

	mbx->size = IXGBE_VFMAILBOX_SIZE;

	mbx->ops.read = ixgbe_read_mbx_vf;
	mbx->ops.write = ixgbe_write_mbx_vf;
	mbx->ops.read_posted = ixgbe_read_posted_mbx;
	mbx->ops.write_posted = ixgbe_write_posted_mbx;
	mbx->ops.check_for_msg = ixgbe_check_for_msg_vf;
	mbx->ops.check_for_ack = ixgbe_check_for_ack_vf;
	mbx->ops.check_for_rst = ixgbe_check_for_rst_vf;

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

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

	if (mbvficr & mask) {
		ret_val = IXGBE_SUCCESS;
		IXGBE_WRITE_REG(hw, IXGBE_MBVFICR(index), mask);
	}

	return ret_val;
}

/**
 *  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 ret_val = IXGBE_ERR_MBX;
	s32 index = IXGBE_MBVFICR_INDEX(vf_number);
	u32 vf_bit = vf_number % 16;

	DEBUGFUNC("ixgbe_check_for_msg_pf");

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

	return ret_val;
}

/**
 *  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 ret_val = IXGBE_ERR_MBX;
	s32 index = IXGBE_MBVFICR_INDEX(vf_number);
	u32 vf_bit = vf_number % 16;

	DEBUGFUNC("ixgbe_check_for_ack_pf");

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

	return ret_val;
}

/**
 *  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;
	s32 ret_val = IXGBE_ERR_MBX;

	DEBUGFUNC("ixgbe_check_for_rst_pf");

	switch (hw->mac.type) {
	case ixgbe_mac_82599EB:
		vflre = IXGBE_READ_REG(hw, IXGBE_VFLRE(reg_offset));
		break;
	case ixgbe_mac_X550:
	case ixgbe_mac_X550EM_x:
	case ixgbe_mac_X550EM_a:
	case ixgbe_mac_X540:
		vflre = IXGBE_READ_REG(hw, IXGBE_VFLREC(reg_offset));
		break;
	default:
		break;
	}

	if (vflre & (1 << vf_shift)) {
		ret_val = IXGBE_SUCCESS;
		IXGBE_WRITE_REG(hw, IXGBE_VFLREC(reg_offset), (1 << vf_shift));
		hw->mbx.stats.rsts++;
	}

	return ret_val;
}

/**
 *  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)
{
	s32 ret_val = IXGBE_ERR_MBX;
	u32 p2v_mailbox;

	DEBUGFUNC("ixgbe_obtain_mbx_lock_pf");

	/* 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)
		ret_val = IXGBE_SUCCESS;
	else
		ERROR_REPORT2(IXGBE_ERROR_POLLING,
			   "Failed to obtain mailbox lock for VF%d", vf_number);


	return ret_val;
}

/**
 *  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;

	DEBUGFUNC("ixgbe_write_mbx_pf");

	/* lock the mailbox to prevent pf/vf race condition */
	ret_val = ixgbe_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 */
	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++;

out_no_write:
	return ret_val;

}

/**
 *  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;

	DEBUGFUNC("ixgbe_read_mbx_pf");

	/* lock the mailbox to prevent pf/vf race condition */
	ret_val = ixgbe_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] = 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++;

out_no_read:
	return ret_val;
}

/**
 *  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->size = IXGBE_VFMAILBOX_SIZE;

	mbx->ops.read = ixgbe_read_mbx_pf;
	mbx->ops.write = ixgbe_write_mbx_pf;
	mbx->ops.read_posted = ixgbe_read_posted_mbx;
	mbx->ops.write_posted = ixgbe_write_posted_mbx;
	mbx->ops.check_for_msg = ixgbe_check_for_msg_pf;
	mbx->ops.check_for_ack = ixgbe_check_for_ack_pf;
	mbx->ops.check_for_rst = ixgbe_check_for_rst_pf;

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