1 /*******************************************************************************
2 
3   Intel(R) 82576 Virtual Function Linux driver
4   Copyright(c) 2009 - 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, see <http://www.gnu.org/licenses/>.
17 
18   The full GNU General Public License is included in this distribution in
19   the file called "COPYING".
20 
21   Contact Information:
22   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
23   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24 
25 *******************************************************************************/
26 
27 #include "mbx.h"
28 
29 /**
30  *  e1000_poll_for_msg - Wait for message notification
31  *  @hw: pointer to the HW structure
32  *
33  *  returns SUCCESS if it successfully received a message notification
34  **/
35 static s32 e1000_poll_for_msg(struct e1000_hw *hw)
36 {
37 	struct e1000_mbx_info *mbx = &hw->mbx;
38 	int countdown = mbx->timeout;
39 
40 	if (!mbx->ops.check_for_msg)
41 		goto out;
42 
43 	while (countdown && mbx->ops.check_for_msg(hw)) {
44 		countdown--;
45 		udelay(mbx->usec_delay);
46 	}
47 
48 	/* if we failed, all future posted messages fail until reset */
49 	if (!countdown)
50 		mbx->timeout = 0;
51 out:
52 	return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
53 }
54 
55 /**
56  *  e1000_poll_for_ack - Wait for message acknowledgment
57  *  @hw: pointer to the HW structure
58  *
59  *  returns SUCCESS if it successfully received a message acknowledgment
60  **/
61 static s32 e1000_poll_for_ack(struct e1000_hw *hw)
62 {
63 	struct e1000_mbx_info *mbx = &hw->mbx;
64 	int countdown = mbx->timeout;
65 
66 	if (!mbx->ops.check_for_ack)
67 		goto out;
68 
69 	while (countdown && mbx->ops.check_for_ack(hw)) {
70 		countdown--;
71 		udelay(mbx->usec_delay);
72 	}
73 
74 	/* if we failed, all future posted messages fail until reset */
75 	if (!countdown)
76 		mbx->timeout = 0;
77 out:
78 	return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
79 }
80 
81 /**
82  *  e1000_read_posted_mbx - Wait for message notification and receive message
83  *  @hw: pointer to the HW structure
84  *  @msg: The message buffer
85  *  @size: Length of buffer
86  *
87  *  returns SUCCESS if it successfully received a message notification and
88  *  copied it into the receive buffer.
89  **/
90 static s32 e1000_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
91 {
92 	struct e1000_mbx_info *mbx = &hw->mbx;
93 	s32 ret_val = -E1000_ERR_MBX;
94 
95 	if (!mbx->ops.read)
96 		goto out;
97 
98 	ret_val = e1000_poll_for_msg(hw);
99 
100 	/* if ack received read message, otherwise we timed out */
101 	if (!ret_val)
102 		ret_val = mbx->ops.read(hw, msg, size);
103 out:
104 	return ret_val;
105 }
106 
107 /**
108  *  e1000_write_posted_mbx - Write a message to the mailbox, wait for ack
109  *  @hw: pointer to the HW structure
110  *  @msg: The message buffer
111  *  @size: Length of buffer
112  *
113  *  returns SUCCESS if it successfully copied message into the buffer and
114  *  received an ack to that message within delay * timeout period
115  **/
116 static s32 e1000_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
117 {
118 	struct e1000_mbx_info *mbx = &hw->mbx;
119 	s32 ret_val = -E1000_ERR_MBX;
120 
121 	/* exit if we either can't write or there isn't a defined timeout */
122 	if (!mbx->ops.write || !mbx->timeout)
123 		goto out;
124 
125 	/* send msg*/
126 	ret_val = mbx->ops.write(hw, msg, size);
127 
128 	/* if msg sent wait until we receive an ack */
129 	if (!ret_val)
130 		ret_val = e1000_poll_for_ack(hw);
131 out:
132 	return ret_val;
133 }
134 
135 /**
136  *  e1000_read_v2p_mailbox - read v2p mailbox
137  *  @hw: pointer to the HW structure
138  *
139  *  This function is used to read the v2p mailbox without losing the read to
140  *  clear status bits.
141  **/
142 static u32 e1000_read_v2p_mailbox(struct e1000_hw *hw)
143 {
144 	u32 v2p_mailbox = er32(V2PMAILBOX(0));
145 
146 	v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
147 	hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
148 
149 	return v2p_mailbox;
150 }
151 
152 /**
153  *  e1000_check_for_bit_vf - Determine if a status bit was set
154  *  @hw: pointer to the HW structure
155  *  @mask: bitmask for bits to be tested and cleared
156  *
157  *  This function is used to check for the read to clear bits within
158  *  the V2P mailbox.
159  **/
160 static s32 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
161 {
162 	u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
163 	s32 ret_val = -E1000_ERR_MBX;
164 
165 	if (v2p_mailbox & mask)
166 		ret_val = E1000_SUCCESS;
167 
168 	hw->dev_spec.vf.v2p_mailbox &= ~mask;
169 
170 	return ret_val;
171 }
172 
173 /**
174  *  e1000_check_for_msg_vf - checks to see if the PF has sent mail
175  *  @hw: pointer to the HW structure
176  *
177  *  returns SUCCESS if the PF has set the Status bit or else ERR_MBX
178  **/
179 static s32 e1000_check_for_msg_vf(struct e1000_hw *hw)
180 {
181 	s32 ret_val = -E1000_ERR_MBX;
182 
183 	if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
184 		ret_val = E1000_SUCCESS;
185 		hw->mbx.stats.reqs++;
186 	}
187 
188 	return ret_val;
189 }
190 
191 /**
192  *  e1000_check_for_ack_vf - checks to see if the PF has ACK'd
193  *  @hw: pointer to the HW structure
194  *
195  *  returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
196  **/
197 static s32 e1000_check_for_ack_vf(struct e1000_hw *hw)
198 {
199 	s32 ret_val = -E1000_ERR_MBX;
200 
201 	if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
202 		ret_val = E1000_SUCCESS;
203 		hw->mbx.stats.acks++;
204 	}
205 
206 	return ret_val;
207 }
208 
209 /**
210  *  e1000_check_for_rst_vf - checks to see if the PF has reset
211  *  @hw: pointer to the HW structure
212  *
213  *  returns true if the PF has set the reset done bit or else false
214  **/
215 static s32 e1000_check_for_rst_vf(struct e1000_hw *hw)
216 {
217 	s32 ret_val = -E1000_ERR_MBX;
218 
219 	if (!e1000_check_for_bit_vf(hw, (E1000_V2PMAILBOX_RSTD |
220 					 E1000_V2PMAILBOX_RSTI))) {
221 		ret_val = E1000_SUCCESS;
222 		hw->mbx.stats.rsts++;
223 	}
224 
225 	return ret_val;
226 }
227 
228 /**
229  *  e1000_obtain_mbx_lock_vf - obtain mailbox lock
230  *  @hw: pointer to the HW structure
231  *
232  *  return SUCCESS if we obtained the mailbox lock
233  **/
234 static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
235 {
236 	s32 ret_val = -E1000_ERR_MBX;
237 
238 	/* Take ownership of the buffer */
239 	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
240 
241 	/* reserve mailbox for VF use */
242 	if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU)
243 		ret_val = E1000_SUCCESS;
244 
245 	return ret_val;
246 }
247 
248 /**
249  *  e1000_write_mbx_vf - Write a message to the mailbox
250  *  @hw: pointer to the HW structure
251  *  @msg: The message buffer
252  *  @size: Length of buffer
253  *
254  *  returns SUCCESS if it successfully copied message into the buffer
255  **/
256 static s32 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
257 {
258 	s32 err;
259 	u16 i;
260 
261 	/* lock the mailbox to prevent pf/vf race condition */
262 	err = e1000_obtain_mbx_lock_vf(hw);
263 	if (err)
264 		goto out_no_write;
265 
266 	/* flush any ack or msg as we are going to overwrite mailbox */
267 	e1000_check_for_ack_vf(hw);
268 	e1000_check_for_msg_vf(hw);
269 
270 	/* copy the caller specified message to the mailbox memory buffer */
271 	for (i = 0; i < size; i++)
272 		array_ew32(VMBMEM(0), i, msg[i]);
273 
274 	/* update stats */
275 	hw->mbx.stats.msgs_tx++;
276 
277 	/* Drop VFU and interrupt the PF to tell it a message has been sent */
278 	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
279 
280 out_no_write:
281 	return err;
282 }
283 
284 /**
285  *  e1000_read_mbx_vf - Reads a message from the inbox intended for VF
286  *  @hw: pointer to the HW structure
287  *  @msg: The message buffer
288  *  @size: Length of buffer
289  *
290  *  returns SUCCESS if it successfully read message from buffer
291  **/
292 static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
293 {
294 	s32 err;
295 	u16 i;
296 
297 	/* lock the mailbox to prevent pf/vf race condition */
298 	err = e1000_obtain_mbx_lock_vf(hw);
299 	if (err)
300 		goto out_no_read;
301 
302 	/* copy the message from the mailbox memory buffer */
303 	for (i = 0; i < size; i++)
304 		msg[i] = array_er32(VMBMEM(0), i);
305 
306 	/* Acknowledge receipt and release mailbox, then we're done */
307 	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
308 
309 	/* update stats */
310 	hw->mbx.stats.msgs_rx++;
311 
312 out_no_read:
313 	return err;
314 }
315 
316 /**
317  *  e1000_init_mbx_params_vf - set initial values for VF mailbox
318  *  @hw: pointer to the HW structure
319  *
320  *  Initializes the hw->mbx struct to correct values for VF mailbox
321  */
322 s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
323 {
324 	struct e1000_mbx_info *mbx = &hw->mbx;
325 
326 	/* start mailbox as timed out and let the reset_hw call set the timeout
327 	 * value to being communications
328 	 */
329 	mbx->timeout = 0;
330 	mbx->usec_delay = E1000_VF_MBX_INIT_DELAY;
331 
332 	mbx->size = E1000_VFMAILBOX_SIZE;
333 
334 	mbx->ops.read = e1000_read_mbx_vf;
335 	mbx->ops.write = e1000_write_mbx_vf;
336 	mbx->ops.read_posted = e1000_read_posted_mbx;
337 	mbx->ops.write_posted = e1000_write_posted_mbx;
338 	mbx->ops.check_for_msg = e1000_check_for_msg_vf;
339 	mbx->ops.check_for_ack = e1000_check_for_ack_vf;
340 	mbx->ops.check_for_rst = e1000_check_for_rst_vf;
341 
342 	mbx->stats.msgs_tx = 0;
343 	mbx->stats.msgs_rx = 0;
344 	mbx->stats.reqs = 0;
345 	mbx->stats.acks = 0;
346 	mbx->stats.rsts = 0;
347 
348 	return E1000_SUCCESS;
349 }
350