1/*******************************************************************************
  2
  3  Intel 82599 Virtual Function driver
  4  Copyright(c) 1999 - 2012 Intel Corporation.
  5
  6  This program is free software; you can redistribute it and/or modify it
  7  under the terms and conditions of the GNU General Public License,
  8  version 2, as published by the Free Software Foundation.
  9
 10  This program is distributed in the hope it will be useful, but WITHOUT
 11  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 13  more details.
 14
 15  You should have received a copy of the GNU General Public License along with
 16  this program; if not, write to the Free Software Foundation, Inc.,
 17  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 18
 19  The full GNU General Public License is included in this distribution in
 20  the file called "COPYING".
 21
 22  Contact Information:
 23  e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 24  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 25
 26*******************************************************************************/
 27
 28#include "mbx.h"
 29#include "ixgbevf.h"
 30
 31/**
 32 *  ixgbevf_poll_for_msg - Wait for message notification
 33 *  @hw: pointer to the HW structure
 34 *
 35 *  returns 0 if it successfully received a message notification
 36 **/
 37static s32 ixgbevf_poll_for_msg(struct ixgbe_hw *hw)
 38{
 39	struct ixgbe_mbx_info *mbx = &hw->mbx;
 40	int countdown = mbx->timeout;
 41
 42	while (countdown && mbx->ops.check_for_msg(hw)) {
 43		countdown--;
 44		udelay(mbx->udelay);
 45	}
 46
 47	/* if we failed, all future posted messages fail until reset */
 48	if (!countdown)
 49		mbx->timeout = 0;
 50
 51	return countdown ? 0 : IXGBE_ERR_MBX;
 52}
 53
 54/**
 55 *  ixgbevf_poll_for_ack - Wait for message acknowledgement
 56 *  @hw: pointer to the HW structure
 57 *
 58 *  returns 0 if it successfully received a message acknowledgement
 59 **/
 60static s32 ixgbevf_poll_for_ack(struct ixgbe_hw *hw)
 61{
 62	struct ixgbe_mbx_info *mbx = &hw->mbx;
 63	int countdown = mbx->timeout;
 64
 65	while (countdown && mbx->ops.check_for_ack(hw)) {
 66		countdown--;
 67		udelay(mbx->udelay);
 68	}
 69
 70	/* if we failed, all future posted messages fail until reset */
 71	if (!countdown)
 72		mbx->timeout = 0;
 73
 74	return countdown ? 0 : IXGBE_ERR_MBX;
 75}
 76
 77/**
 78 *  ixgbevf_read_posted_mbx - Wait for message notification and receive message
 79 *  @hw: pointer to the HW structure
 80 *  @msg: The message buffer
 81 *  @size: Length of buffer
 82 *
 83 *  returns 0 if it successfully received a message notification and
 84 *  copied it into the receive buffer.
 85 **/
 86static s32 ixgbevf_read_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
 87{
 88	struct ixgbe_mbx_info *mbx = &hw->mbx;
 89	s32 ret_val = -IXGBE_ERR_MBX;
 90
 91	if (!mbx->ops.read)
 92		goto out;
 93
 94	ret_val = ixgbevf_poll_for_msg(hw);
 95
 96	/* if ack received read message, otherwise we timed out */
 97	if (!ret_val)
 98		ret_val = mbx->ops.read(hw, msg, size);
 99out:
100	return ret_val;
101}
102
103/**
104 *  ixgbevf_write_posted_mbx - Write a message to the mailbox, wait for ack
105 *  @hw: pointer to the HW structure
106 *  @msg: The message buffer
107 *  @size: Length of buffer
108 *
109 *  returns 0 if it successfully copied message into the buffer and
110 *  received an ack to that message within delay * timeout period
111 **/
112static s32 ixgbevf_write_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
113{
114	struct ixgbe_mbx_info *mbx = &hw->mbx;
115	s32 ret_val = -IXGBE_ERR_MBX;
116
117	/* exit if either we can't write or there isn't a defined timeout */
118	if (!mbx->ops.write || !mbx->timeout)
119		goto out;
120
121	/* send msg */
122	ret_val = mbx->ops.write(hw, msg, size);
123
124	/* if msg sent wait until we receive an ack */
125	if (!ret_val)
126		ret_val = ixgbevf_poll_for_ack(hw);
127out:
128	return ret_val;
129}
130
131/**
132 *  ixgbevf_read_v2p_mailbox - read v2p mailbox
133 *  @hw: pointer to the HW structure
134 *
135 *  This function is used to read the v2p mailbox without losing the read to
136 *  clear status bits.
137 **/
138static u32 ixgbevf_read_v2p_mailbox(struct ixgbe_hw *hw)
139{
140	u32 v2p_mailbox = IXGBE_READ_REG(hw, IXGBE_VFMAILBOX);
141
142	v2p_mailbox |= hw->mbx.v2p_mailbox;
143	hw->mbx.v2p_mailbox |= v2p_mailbox & IXGBE_VFMAILBOX_R2C_BITS;
144
145	return v2p_mailbox;
146}
147
148/**
149 *  ixgbevf_check_for_bit_vf - Determine if a status bit was set
150 *  @hw: pointer to the HW structure
151 *  @mask: bitmask for bits to be tested and cleared
152 *
153 *  This function is used to check for the read to clear bits within
154 *  the V2P mailbox.
155 **/
156static s32 ixgbevf_check_for_bit_vf(struct ixgbe_hw *hw, u32 mask)
157{
158	u32 v2p_mailbox = ixgbevf_read_v2p_mailbox(hw);
159	s32 ret_val = IXGBE_ERR_MBX;
160
161	if (v2p_mailbox & mask)
162		ret_val = 0;
163
164	hw->mbx.v2p_mailbox &= ~mask;
165
166	return ret_val;
167}
168
169/**
170 *  ixgbevf_check_for_msg_vf - checks to see if the PF has sent mail
171 *  @hw: pointer to the HW structure
172 *
173 *  returns 0 if the PF has set the Status bit or else ERR_MBX
174 **/
175static s32 ixgbevf_check_for_msg_vf(struct ixgbe_hw *hw)
176{
177	s32 ret_val = IXGBE_ERR_MBX;
178
179	if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFSTS)) {
180		ret_val = 0;
181		hw->mbx.stats.reqs++;
182	}
183
184	return ret_val;
185}
186
187/**
188 *  ixgbevf_check_for_ack_vf - checks to see if the PF has ACK'd
189 *  @hw: pointer to the HW structure
190 *
191 *  returns 0 if the PF has set the ACK bit or else ERR_MBX
192 **/
193static s32 ixgbevf_check_for_ack_vf(struct ixgbe_hw *hw)
194{
195	s32 ret_val = IXGBE_ERR_MBX;
196
197	if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFACK)) {
198		ret_val = 0;
199		hw->mbx.stats.acks++;
200	}
201
202	return ret_val;
203}
204
205/**
206 *  ixgbevf_check_for_rst_vf - checks to see if the PF has reset
207 *  @hw: pointer to the HW structure
208 *
209 *  returns true if the PF has set the reset done bit or else false
210 **/
211static s32 ixgbevf_check_for_rst_vf(struct ixgbe_hw *hw)
212{
213	s32 ret_val = IXGBE_ERR_MBX;
214
215	if (!ixgbevf_check_for_bit_vf(hw, (IXGBE_VFMAILBOX_RSTD |
216					 IXGBE_VFMAILBOX_RSTI))) {
217		ret_val = 0;
218		hw->mbx.stats.rsts++;
219	}
220
221	return ret_val;
222}
223
224/**
225 *  ixgbevf_obtain_mbx_lock_vf - obtain mailbox lock
226 *  @hw: pointer to the HW structure
227 *
228 *  return 0 if we obtained the mailbox lock
229 **/
230static s32 ixgbevf_obtain_mbx_lock_vf(struct ixgbe_hw *hw)
231{
232	s32 ret_val = IXGBE_ERR_MBX;
233
234	/* Take ownership of the buffer */
235	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_VFU);
236
237	/* reserve mailbox for vf use */
238	if (ixgbevf_read_v2p_mailbox(hw) & IXGBE_VFMAILBOX_VFU)
239		ret_val = 0;
240
241	return ret_val;
242}
243
244/**
245 *  ixgbevf_write_mbx_vf - Write a message to the mailbox
246 *  @hw: pointer to the HW structure
247 *  @msg: The message buffer
248 *  @size: Length of buffer
249 *
250 *  returns 0 if it successfully copied message into the buffer
251 **/
252static s32 ixgbevf_write_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
253{
254	s32 ret_val;
255	u16 i;
256
257
258	/* lock the mailbox to prevent pf/vf race condition */
259	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
260	if (ret_val)
261		goto out_no_write;
262
263	/* flush msg and acks as we are overwriting the message buffer */
264	ixgbevf_check_for_msg_vf(hw);
265	ixgbevf_check_for_ack_vf(hw);
266
267	/* copy the caller specified message to the mailbox memory buffer */
268	for (i = 0; i < size; i++)
269		IXGBE_WRITE_REG_ARRAY(hw, IXGBE_VFMBMEM, i, msg[i]);
270
271	/* update stats */
272	hw->mbx.stats.msgs_tx++;
273
274	/* Drop VFU and interrupt the PF to tell it a message has been sent */
275	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_REQ);
276
277out_no_write:
278	return ret_val;
279}
280
281/**
282 *  ixgbevf_read_mbx_vf - Reads a message from the inbox intended for vf
283 *  @hw: pointer to the HW structure
284 *  @msg: The message buffer
285 *  @size: Length of buffer
286 *
287 *  returns 0 if it successfully read message from buffer
288 **/
289static s32 ixgbevf_read_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
290{
291	s32 ret_val = 0;
292	u16 i;
293
294	/* lock the mailbox to prevent pf/vf race condition */
295	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
296	if (ret_val)
297		goto out_no_read;
298
299	/* copy the message from the mailbox memory buffer */
300	for (i = 0; i < size; i++)
301		msg[i] = IXGBE_READ_REG_ARRAY(hw, IXGBE_VFMBMEM, i);
302
303	/* Acknowledge receipt and release mailbox, then we're done */
304	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_ACK);
305
306	/* update stats */
307	hw->mbx.stats.msgs_rx++;
308
309out_no_read:
310	return ret_val;
311}
312
313/**
314 *  ixgbevf_init_mbx_params_vf - set initial values for vf mailbox
315 *  @hw: pointer to the HW structure
316 *
317 *  Initializes the hw->mbx struct to correct values for vf mailbox
318 */
319static s32 ixgbevf_init_mbx_params_vf(struct ixgbe_hw *hw)
320{
321	struct ixgbe_mbx_info *mbx = &hw->mbx;
322
323	/* start mailbox as timed out and let the reset_hw call set the timeout
324	 * value to begin communications */
325	mbx->timeout = 0;
326	mbx->udelay = IXGBE_VF_MBX_INIT_DELAY;
327
328	mbx->size = IXGBE_VFMAILBOX_SIZE;
329
330	mbx->stats.msgs_tx = 0;
331	mbx->stats.msgs_rx = 0;
332	mbx->stats.reqs = 0;
333	mbx->stats.acks = 0;
334	mbx->stats.rsts = 0;
335
336	return 0;
337}
338
339const struct ixgbe_mbx_operations ixgbevf_mbx_ops = {
340	.init_params   = ixgbevf_init_mbx_params_vf,
341	.read          = ixgbevf_read_mbx_vf,
342	.write         = ixgbevf_write_mbx_vf,
343	.read_posted   = ixgbevf_read_posted_mbx,
344	.write_posted  = ixgbevf_write_posted_mbx,
345	.check_for_msg = ixgbevf_check_for_msg_vf,
346	.check_for_ack = ixgbevf_check_for_ack_vf,
347	.check_for_rst = ixgbevf_check_for_rst_vf,
348};
349