xref: /linux/drivers/net/ethernet/intel/ixgbevf/mbx.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*******************************************************************************
2 
3   Intel 82599 Virtual Function driver
4   Copyright(c) 1999 - 2010 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 
30 /**
31  *  ixgbevf_poll_for_msg - Wait for message notification
32  *  @hw: pointer to the HW structure
33  *
34  *  returns 0 if it successfully received a message notification
35  **/
36 static s32 ixgbevf_poll_for_msg(struct ixgbe_hw *hw)
37 {
38 	struct ixgbe_mbx_info *mbx = &hw->mbx;
39 	int countdown = mbx->timeout;
40 
41 	while (countdown && mbx->ops.check_for_msg(hw)) {
42 		countdown--;
43 		udelay(mbx->udelay);
44 	}
45 
46 	/* if we failed, all future posted messages fail until reset */
47 	if (!countdown)
48 		mbx->timeout = 0;
49 
50 	return countdown ? 0 : IXGBE_ERR_MBX;
51 }
52 
53 /**
54  *  ixgbevf_poll_for_ack - Wait for message acknowledgement
55  *  @hw: pointer to the HW structure
56  *
57  *  returns 0 if it successfully received a message acknowledgement
58  **/
59 static s32 ixgbevf_poll_for_ack(struct ixgbe_hw *hw)
60 {
61 	struct ixgbe_mbx_info *mbx = &hw->mbx;
62 	int countdown = mbx->timeout;
63 
64 	while (countdown && mbx->ops.check_for_ack(hw)) {
65 		countdown--;
66 		udelay(mbx->udelay);
67 	}
68 
69 	/* if we failed, all future posted messages fail until reset */
70 	if (!countdown)
71 		mbx->timeout = 0;
72 
73 	return countdown ? 0 : IXGBE_ERR_MBX;
74 }
75 
76 /**
77  *  ixgbevf_read_posted_mbx - Wait for message notification and receive message
78  *  @hw: pointer to the HW structure
79  *  @msg: The message buffer
80  *  @size: Length of buffer
81  *
82  *  returns 0 if it successfully received a message notification and
83  *  copied it into the receive buffer.
84  **/
85 static s32 ixgbevf_read_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
86 {
87 	struct ixgbe_mbx_info *mbx = &hw->mbx;
88 	s32 ret_val = IXGBE_ERR_MBX;
89 
90 	ret_val = ixgbevf_poll_for_msg(hw);
91 
92 	/* if ack received read message, otherwise we timed out */
93 	if (!ret_val)
94 		ret_val = mbx->ops.read(hw, msg, size);
95 
96 	return ret_val;
97 }
98 
99 /**
100  *  ixgbevf_write_posted_mbx - Write a message to the mailbox, wait for ack
101  *  @hw: pointer to the HW structure
102  *  @msg: The message buffer
103  *  @size: Length of buffer
104  *
105  *  returns 0 if it successfully copied message into the buffer and
106  *  received an ack to that message within delay * timeout period
107  **/
108 static s32 ixgbevf_write_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
109 {
110 	struct ixgbe_mbx_info *mbx = &hw->mbx;
111 	s32 ret_val;
112 
113 	/* send msg */
114 	ret_val = mbx->ops.write(hw, msg, size);
115 
116 	/* if msg sent wait until we receive an ack */
117 	if (!ret_val)
118 		ret_val = ixgbevf_poll_for_ack(hw);
119 
120 	return ret_val;
121 }
122 
123 /**
124  *  ixgbevf_read_v2p_mailbox - read v2p mailbox
125  *  @hw: pointer to the HW structure
126  *
127  *  This function is used to read the v2p mailbox without losing the read to
128  *  clear status bits.
129  **/
130 static u32 ixgbevf_read_v2p_mailbox(struct ixgbe_hw *hw)
131 {
132 	u32 v2p_mailbox = IXGBE_READ_REG(hw, IXGBE_VFMAILBOX);
133 
134 	v2p_mailbox |= hw->mbx.v2p_mailbox;
135 	hw->mbx.v2p_mailbox |= v2p_mailbox & IXGBE_VFMAILBOX_R2C_BITS;
136 
137 	return v2p_mailbox;
138 }
139 
140 /**
141  *  ixgbevf_check_for_bit_vf - Determine if a status bit was set
142  *  @hw: pointer to the HW structure
143  *  @mask: bitmask for bits to be tested and cleared
144  *
145  *  This function is used to check for the read to clear bits within
146  *  the V2P mailbox.
147  **/
148 static s32 ixgbevf_check_for_bit_vf(struct ixgbe_hw *hw, u32 mask)
149 {
150 	u32 v2p_mailbox = ixgbevf_read_v2p_mailbox(hw);
151 	s32 ret_val = IXGBE_ERR_MBX;
152 
153 	if (v2p_mailbox & mask)
154 		ret_val = 0;
155 
156 	hw->mbx.v2p_mailbox &= ~mask;
157 
158 	return ret_val;
159 }
160 
161 /**
162  *  ixgbevf_check_for_msg_vf - checks to see if the PF has sent mail
163  *  @hw: pointer to the HW structure
164  *
165  *  returns 0 if the PF has set the Status bit or else ERR_MBX
166  **/
167 static s32 ixgbevf_check_for_msg_vf(struct ixgbe_hw *hw)
168 {
169 	s32 ret_val = IXGBE_ERR_MBX;
170 
171 	if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFSTS)) {
172 		ret_val = 0;
173 		hw->mbx.stats.reqs++;
174 	}
175 
176 	return ret_val;
177 }
178 
179 /**
180  *  ixgbevf_check_for_ack_vf - checks to see if the PF has ACK'd
181  *  @hw: pointer to the HW structure
182  *
183  *  returns 0 if the PF has set the ACK bit or else ERR_MBX
184  **/
185 static s32 ixgbevf_check_for_ack_vf(struct ixgbe_hw *hw)
186 {
187 	s32 ret_val = IXGBE_ERR_MBX;
188 
189 	if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFACK)) {
190 		ret_val = 0;
191 		hw->mbx.stats.acks++;
192 	}
193 
194 	return ret_val;
195 }
196 
197 /**
198  *  ixgbevf_check_for_rst_vf - checks to see if the PF has reset
199  *  @hw: pointer to the HW structure
200  *
201  *  returns true if the PF has set the reset done bit or else false
202  **/
203 static s32 ixgbevf_check_for_rst_vf(struct ixgbe_hw *hw)
204 {
205 	s32 ret_val = IXGBE_ERR_MBX;
206 
207 	if (!ixgbevf_check_for_bit_vf(hw, (IXGBE_VFMAILBOX_RSTD |
208 					 IXGBE_VFMAILBOX_RSTI))) {
209 		ret_val = 0;
210 		hw->mbx.stats.rsts++;
211 	}
212 
213 	return ret_val;
214 }
215 
216 /**
217  *  ixgbevf_obtain_mbx_lock_vf - obtain mailbox lock
218  *  @hw: pointer to the HW structure
219  *
220  *  return 0 if we obtained the mailbox lock
221  **/
222 static s32 ixgbevf_obtain_mbx_lock_vf(struct ixgbe_hw *hw)
223 {
224 	s32 ret_val = IXGBE_ERR_MBX;
225 
226 	/* Take ownership of the buffer */
227 	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_VFU);
228 
229 	/* reserve mailbox for vf use */
230 	if (ixgbevf_read_v2p_mailbox(hw) & IXGBE_VFMAILBOX_VFU)
231 		ret_val = 0;
232 
233 	return ret_val;
234 }
235 
236 /**
237  *  ixgbevf_write_mbx_vf - Write a message to the mailbox
238  *  @hw: pointer to the HW structure
239  *  @msg: The message buffer
240  *  @size: Length of buffer
241  *
242  *  returns 0 if it successfully copied message into the buffer
243  **/
244 static s32 ixgbevf_write_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
245 {
246 	s32 ret_val;
247 	u16 i;
248 
249 
250 	/* lock the mailbox to prevent pf/vf race condition */
251 	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
252 	if (ret_val)
253 		goto out_no_write;
254 
255 	/* flush msg and acks as we are overwriting the message buffer */
256 	ixgbevf_check_for_msg_vf(hw);
257 	ixgbevf_check_for_ack_vf(hw);
258 
259 	/* copy the caller specified message to the mailbox memory buffer */
260 	for (i = 0; i < size; i++)
261 		IXGBE_WRITE_REG_ARRAY(hw, IXGBE_VFMBMEM, i, msg[i]);
262 
263 	/* update stats */
264 	hw->mbx.stats.msgs_tx++;
265 
266 	/* Drop VFU and interrupt the PF to tell it a message has been sent */
267 	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_REQ);
268 
269 out_no_write:
270 	return ret_val;
271 }
272 
273 /**
274  *  ixgbevf_read_mbx_vf - Reads a message from the inbox intended for vf
275  *  @hw: pointer to the HW structure
276  *  @msg: The message buffer
277  *  @size: Length of buffer
278  *
279  *  returns 0 if it successfully read message from buffer
280  **/
281 static s32 ixgbevf_read_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
282 {
283 	s32 ret_val = 0;
284 	u16 i;
285 
286 	/* lock the mailbox to prevent pf/vf race condition */
287 	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
288 	if (ret_val)
289 		goto out_no_read;
290 
291 	/* copy the message from the mailbox memory buffer */
292 	for (i = 0; i < size; i++)
293 		msg[i] = IXGBE_READ_REG_ARRAY(hw, IXGBE_VFMBMEM, i);
294 
295 	/* Acknowledge receipt and release mailbox, then we're done */
296 	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_ACK);
297 
298 	/* update stats */
299 	hw->mbx.stats.msgs_rx++;
300 
301 out_no_read:
302 	return ret_val;
303 }
304 
305 /**
306  *  ixgbevf_init_mbx_params_vf - set initial values for vf mailbox
307  *  @hw: pointer to the HW structure
308  *
309  *  Initializes the hw->mbx struct to correct values for vf mailbox
310  */
311 static s32 ixgbevf_init_mbx_params_vf(struct ixgbe_hw *hw)
312 {
313 	struct ixgbe_mbx_info *mbx = &hw->mbx;
314 
315 	/* start mailbox as timed out and let the reset_hw call set the timeout
316 	 * value to begin communications */
317 	mbx->timeout = 0;
318 	mbx->udelay = IXGBE_VF_MBX_INIT_DELAY;
319 
320 	mbx->size = IXGBE_VFMAILBOX_SIZE;
321 
322 	mbx->stats.msgs_tx = 0;
323 	mbx->stats.msgs_rx = 0;
324 	mbx->stats.reqs = 0;
325 	mbx->stats.acks = 0;
326 	mbx->stats.rsts = 0;
327 
328 	return 0;
329 }
330 
331 struct ixgbe_mbx_operations ixgbevf_mbx_ops = {
332 	.init_params   = ixgbevf_init_mbx_params_vf,
333 	.read          = ixgbevf_read_mbx_vf,
334 	.write         = ixgbevf_write_mbx_vf,
335 	.read_posted   = ixgbevf_read_posted_mbx,
336 	.write_posted  = ixgbevf_write_posted_mbx,
337 	.check_for_msg = ixgbevf_check_for_msg_vf,
338 	.check_for_ack = ixgbevf_check_for_ack_vf,
339 	.check_for_rst = ixgbevf_check_for_rst_vf,
340 };
341 
342