FreeBSD/Linux Kernel Cross Reference
sys/dev/e1000/e1000_mbx.c

     /******************************************************************************
       SPDX-License-Identifier: BSD-3-Clause
     
       Copyright (c) 2001-2020, Intel Corporation
       All rights reserved.
     
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      AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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      ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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    ******************************************************************************/
    /*$FreeBSD$*/
    
    #include "e1000_mbx.h"
    
    /**
     *  e1000_null_mbx_check_for_flag - No-op function, return 0
     *  @hw: pointer to the HW structure
     *  @mbx_id: id of mailbox to read
     **/
    static s32 e1000_null_mbx_check_for_flag(struct e1000_hw E1000_UNUSEDARG *hw,
                                             u16 E1000_UNUSEDARG mbx_id)
    {
            DEBUGFUNC("e1000_null_mbx_check_flag");
    
            return E1000_SUCCESS;
    }
    
    /**
     *  e1000_null_mbx_transact - No-op function, return 0
     *  @hw: pointer to the HW structure
     *  @msg: The message buffer
     *  @size: Length of buffer
     *  @mbx_id: id of mailbox to read
     **/
    static s32 e1000_null_mbx_transact(struct e1000_hw E1000_UNUSEDARG *hw,
                                       u32 E1000_UNUSEDARG *msg,
                                       u16 E1000_UNUSEDARG size,
                                       u16 E1000_UNUSEDARG mbx_id)
    {
            DEBUGFUNC("e1000_null_mbx_rw_msg");
    
            return E1000_SUCCESS;
    }
    
    /**
     *  e1000_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 e1000_read_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;
    
            DEBUGFUNC("e1000_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;
    }
    
    /**
     *  e1000_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 e1000_write_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           s32 ret_val = E1000_SUCCESS;
   
           DEBUGFUNC("e1000_write_mbx");
   
           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;
   }
   
   /**
    *  e1000_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 e1000_check_for_msg(struct e1000_hw *hw, u16 mbx_id)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_msg");
   
           if (mbx->ops.check_for_msg)
                   ret_val = mbx->ops.check_for_msg(hw, mbx_id);
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_ack(struct e1000_hw *hw, u16 mbx_id)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_ack");
   
           if (mbx->ops.check_for_ack)
                   ret_val = mbx->ops.check_for_ack(hw, mbx_id);
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_rst(struct e1000_hw *hw, u16 mbx_id)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_rst");
   
           if (mbx->ops.check_for_rst)
                   ret_val = mbx->ops.check_for_rst(hw, mbx_id);
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_poll_for_msg(struct e1000_hw *hw, u16 mbx_id)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           int countdown = mbx->timeout;
   
           DEBUGFUNC("e1000_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 we failed, all future posted messages fail until reset */
           if (!countdown)
                   mbx->timeout = 0;
   out:
           return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
   }
   
   /**
    *  e1000_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 e1000_poll_for_ack(struct e1000_hw *hw, u16 mbx_id)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           int countdown = mbx->timeout;
   
           DEBUGFUNC("e1000_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 we failed, all future posted messages fail until reset */
           if (!countdown)
                   mbx->timeout = 0;
   out:
           return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
   }
   
   /**
    *  e1000_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 e1000_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;
   
           DEBUGFUNC("e1000_read_posted_mbx");
   
           if (!mbx->ops.read)
                   goto out;
   
           ret_val = e1000_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;
   }
   
   /**
    *  e1000_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 e1000_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;
   
           DEBUGFUNC("e1000_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 = e1000_poll_for_ack(hw, mbx_id);
   out:
           return ret_val;
   }
   
   /**
    *  e1000_init_mbx_ops_generic - Initialize mbx function pointers
    *  @hw: pointer to the HW structure
    *
    *  Sets the function pointers to no-op functions
    **/
   void e1000_init_mbx_ops_generic(struct e1000_hw *hw)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
           mbx->ops.init_params = e1000_null_ops_generic;
           mbx->ops.read = e1000_null_mbx_transact;
           mbx->ops.write = e1000_null_mbx_transact;
           mbx->ops.check_for_msg = e1000_null_mbx_check_for_flag;
           mbx->ops.check_for_ack = e1000_null_mbx_check_for_flag;
           mbx->ops.check_for_rst = e1000_null_mbx_check_for_flag;
           mbx->ops.read_posted = e1000_read_posted_mbx;
           mbx->ops.write_posted = e1000_write_posted_mbx;
   }
   
   /**
    *  e1000_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 e1000_read_v2p_mailbox(struct e1000_hw *hw)
   {
           u32 v2p_mailbox = E1000_READ_REG(hw, E1000_V2PMAILBOX(0));
   
           v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
           hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
   
           return v2p_mailbox;
   }
   
   /**
    *  e1000_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 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
   {
           u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
           s32 ret_val = -E1000_ERR_MBX;
   
           if (v2p_mailbox & mask)
                   ret_val = E1000_SUCCESS;
   
           hw->dev_spec.vf.v2p_mailbox &= ~mask;
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_msg_vf(struct e1000_hw *hw,
                                     u16 E1000_UNUSEDARG mbx_id)
   {
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_msg_vf");
   
           if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
                   ret_val = E1000_SUCCESS;
                   hw->mbx.stats.reqs++;
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_ack_vf(struct e1000_hw *hw,
                                     u16 E1000_UNUSEDARG mbx_id)
   {
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_ack_vf");
   
           if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
                   ret_val = E1000_SUCCESS;
                   hw->mbx.stats.acks++;
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_rst_vf(struct e1000_hw *hw,
                                     u16 E1000_UNUSEDARG mbx_id)
   {
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_rst_vf");
   
           if (!e1000_check_for_bit_vf(hw, (E1000_V2PMAILBOX_RSTD |
                                            E1000_V2PMAILBOX_RSTI))) {
                   ret_val = E1000_SUCCESS;
                   hw->mbx.stats.rsts++;
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_obtain_mbx_lock_vf - obtain mailbox lock
    *  @hw: pointer to the HW structure
    *
    *  return SUCCESS if we obtained the mailbox lock
    **/
   static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
   {
           s32 ret_val = -E1000_ERR_MBX;
           int count = 10;
   
           DEBUGFUNC("e1000_obtain_mbx_lock_vf");
   
           do {
                   /* Take ownership of the buffer */
                   E1000_WRITE_REG(hw, E1000_V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
   
                   /* reserve mailbox for vf use */
                   if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU) {
                           ret_val = E1000_SUCCESS;
                           break;
                   }
                   usec_delay(1000);
           } while (count-- > 0);
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size,
                                 u16 E1000_UNUSEDARG mbx_id)
   {
           s32 ret_val;
           u16 i;
   
   
           DEBUGFUNC("e1000_write_mbx_vf");
   
           /* lock the mailbox to prevent pf/vf race condition */
           ret_val = e1000_obtain_mbx_lock_vf(hw);
           if (ret_val)
                   goto out_no_write;
   
           /* flush msg and acks as we are overwriting the message buffer */
           e1000_check_for_msg_vf(hw, 0);
           e1000_check_for_ack_vf(hw, 0);
   
           /* copy the caller specified message to the mailbox memory buffer */
           for (i = 0; i < size; i++)
                   E1000_WRITE_REG_ARRAY(hw, E1000_VMBMEM(0), i, msg[i]);
   
           /* update stats */
           hw->mbx.stats.msgs_tx++;
   
           /* Drop VFU and interrupt the PF to tell it a message has been sent */
           E1000_WRITE_REG(hw, E1000_V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
   
   out_no_write:
           return ret_val;
   }
   
   /**
    *  e1000_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 successfully read message from buffer
    **/
   static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size,
                                u16 E1000_UNUSEDARG mbx_id)
   {
           s32 ret_val = E1000_SUCCESS;
           u16 i;
   
           DEBUGFUNC("e1000_read_mbx_vf");
   
           /* lock the mailbox to prevent pf/vf race condition */
           ret_val = e1000_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] = E1000_READ_REG_ARRAY(hw, E1000_VMBMEM(0), i);
   
           /* Acknowledge receipt and release mailbox, then we're done */
           E1000_WRITE_REG(hw, E1000_V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
   
           /* update stats */
           hw->mbx.stats.msgs_rx++;
   
   out_no_read:
           return ret_val;
   }
   
   /**
    *  e1000_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
    */
   s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
   {
           struct e1000_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 = E1000_VF_MBX_INIT_DELAY;
   
           mbx->size = E1000_VFMAILBOX_SIZE;
   
           mbx->ops.read = e1000_read_mbx_vf;
           mbx->ops.write = e1000_write_mbx_vf;
           mbx->ops.read_posted = e1000_read_posted_mbx;
           mbx->ops.write_posted = e1000_write_posted_mbx;
           mbx->ops.check_for_msg = e1000_check_for_msg_vf;
           mbx->ops.check_for_ack = e1000_check_for_ack_vf;
           mbx->ops.check_for_rst = e1000_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;
   
           return E1000_SUCCESS;
   }
   
   static s32 e1000_check_for_bit_pf(struct e1000_hw *hw, u32 mask)
   {
           u32 mbvficr = E1000_READ_REG(hw, E1000_MBVFICR);
           s32 ret_val = -E1000_ERR_MBX;
   
           if (mbvficr & mask) {
                   ret_val = E1000_SUCCESS;
                   E1000_WRITE_REG(hw, E1000_MBVFICR, mask);
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_msg_pf(struct e1000_hw *hw, u16 vf_number)
   {
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_msg_pf");
   
           if (!e1000_check_for_bit_pf(hw, E1000_MBVFICR_VFREQ_VF1 << vf_number)) {
                   ret_val = E1000_SUCCESS;
                   hw->mbx.stats.reqs++;
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_ack_pf(struct e1000_hw *hw, u16 vf_number)
   {
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_ack_pf");
   
           if (!e1000_check_for_bit_pf(hw, E1000_MBVFICR_VFACK_VF1 << vf_number)) {
                   ret_val = E1000_SUCCESS;
                   hw->mbx.stats.acks++;
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_check_for_rst_pf(struct e1000_hw *hw, u16 vf_number)
   {
           u32 vflre = E1000_READ_REG(hw, E1000_VFLRE);
           s32 ret_val = -E1000_ERR_MBX;
   
           DEBUGFUNC("e1000_check_for_rst_pf");
   
           if (vflre & (1 << vf_number)) {
                   ret_val = E1000_SUCCESS;
                   E1000_WRITE_REG(hw, E1000_VFLRE, (1 << vf_number));
                   hw->mbx.stats.rsts++;
           }
   
           return ret_val;
   }
   
   /**
    *  e1000_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 e1000_obtain_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
   {
           s32 ret_val = -E1000_ERR_MBX;
           u32 p2v_mailbox;
           int count = 10;
   
           DEBUGFUNC("e1000_obtain_mbx_lock_pf");
   
           do {
                   /* Take ownership of the buffer */
                   E1000_WRITE_REG(hw, E1000_P2VMAILBOX(vf_number),
                                   E1000_P2VMAILBOX_PFU);
   
                   /* reserve mailbox for pf use */
                   p2v_mailbox = E1000_READ_REG(hw, E1000_P2VMAILBOX(vf_number));
                   if (p2v_mailbox & E1000_P2VMAILBOX_PFU) {
                           ret_val = E1000_SUCCESS;
                           break;
                   }
                   usec_delay(1000);
           } while (count-- > 0);
   
           return ret_val;
   
   }
   
   /**
    *  e1000_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 e1000_write_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
                                 u16 vf_number)
   {
           s32 ret_val;
           u16 i;
   
           DEBUGFUNC("e1000_write_mbx_pf");
   
           /* lock the mailbox to prevent pf/vf race condition */
           ret_val = e1000_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 */
           e1000_check_for_msg_pf(hw, vf_number);
           e1000_check_for_ack_pf(hw, vf_number);
   
           /* copy the caller specified message to the mailbox memory buffer */
           for (i = 0; i < size; i++)
                   E1000_WRITE_REG_ARRAY(hw, E1000_VMBMEM(vf_number), i, msg[i]);
   
           /* Interrupt VF to tell it a message has been sent and release buffer*/
           E1000_WRITE_REG(hw, E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_STS);
   
           /* update stats */
           hw->mbx.stats.msgs_tx++;
   
   out_no_write:
           return ret_val;
   
   }
   
   /**
    *  e1000_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 e1000_read_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
                                u16 vf_number)
   {
           s32 ret_val;
           u16 i;
   
           DEBUGFUNC("e1000_read_mbx_pf");
   
           /* lock the mailbox to prevent pf/vf race condition */
           ret_val = e1000_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] = E1000_READ_REG_ARRAY(hw, E1000_VMBMEM(vf_number), i);
   
           /* Acknowledge the message and release buffer */
           E1000_WRITE_REG(hw, E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_ACK);
   
           /* 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 e1000_init_mbx_params_pf(struct e1000_hw *hw)
   {
           struct e1000_mbx_info *mbx = &hw->mbx;
   
           switch (hw->mac.type) {
           case e1000_82576:
           case e1000_i350:
           case e1000_i354:
                   mbx->timeout = 0;
                   mbx->usec_delay = 0;
   
                   mbx->size = E1000_VFMAILBOX_SIZE;
   
                   mbx->ops.read = e1000_read_mbx_pf;
                   mbx->ops.write = e1000_write_mbx_pf;
                   mbx->ops.read_posted = e1000_read_posted_mbx;
                   mbx->ops.write_posted = e1000_write_posted_mbx;
                   mbx->ops.check_for_msg = e1000_check_for_msg_pf;
                   mbx->ops.check_for_ack = e1000_check_for_ack_pf;
                   mbx->ops.check_for_rst = e1000_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;
                   /* FALLTHROUGH */
           default:
                   return E1000_SUCCESS;
           }
   }
   

Cache object: 7bdf11c57ec4cf650f51a43608aa4d62