ixgbe: Mailbox header and code module

The 82599 virtual function device and the master 82599 physical function
device implement a mailbox utility for communication between the devices
using some SRAM scratch memory and a doorbell/answering mechanism enabled
via interrupt and/or polling.  This C module and accompanying header
file implement the base functions for use of this feature.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 479 insertions, 0 deletions

diff --git a/drivers/net/ixgbe/ixgbe_mbx.c b/drivers/net/ixgbe/ixgbe_mbx.c
new file mode 100644
index 0000000..d75f914
--- /dev/null
+++ b/drivers/net/ixgbe/ixgbe_mbx.c
@@ -0,0 +1,479 @@
+/*******************************************************************************
+
+  Intel 10 Gigabit PCI Express Linux driver
+  Copyright(c) 1999 - 2009 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.
+
+  You should have received a copy of the GNU General Public License along with
+  this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+
+  The full GNU General Public License is included in this distribution in
+  the file called "COPYING".
+
+  Contact Information:
+  e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
+  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+
+*******************************************************************************/
+
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include "ixgbe_type.h"
+#include "ixgbe_common.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;
+
+	/* 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 = 0;
+
+	if (size > mbx->size)
+		ret_val = IXGBE_ERR_MBX;
+
+	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;
+
+	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;
+
+	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;
+
+	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;
+
+	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 : 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;
+
+	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 : 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;
+
+	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;
+
+	/* 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
+ *
+ *  Setup 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;
+}
+
+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 = 0;
+		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;
+
+	if (!ixgbe_check_for_bit_pf(hw, IXGBE_MBVFICR_VFREQ_VF1 << vf_bit,
+	                            index)) {
+		ret_val = 0;
+		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;
+
+	if (!ixgbe_check_for_bit_pf(hw, IXGBE_MBVFICR_VFACK_VF1 << vf_bit,
+	                            index)) {
+		ret_val = 0;
+		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;
+
+	if (hw->mac.type == ixgbe_mac_82599EB)
+		vflre = IXGBE_READ_REG(hw, IXGBE_VFLRE(reg_offset));
+
+	if (vflre & (1 << vf_shift)) {
+		ret_val = 0;
+		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;
+
+	/* 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 = 0;
+
+	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;
+
+	/* 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;
+
+	/* 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)
+		return;
+
+	mbx->timeout = 0;
+	mbx->usec_delay = 0;
+
+	mbx->size = IXGBE_VFMAILBOX_SIZE;
+
+	mbx->stats.msgs_tx = 0;
+	mbx->stats.msgs_rx = 0;
+	mbx->stats.reqs = 0;
+	mbx->stats.acks = 0;
+	mbx->stats.rsts = 0;
+}
+
+struct ixgbe_mbx_operations mbx_ops_82599 = {
+	.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,
+};
+