1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2007 - 2018 Intel Corporation. */
3 
4 #include "e1000_mbx.h"
5 
6 /**
7  *  igb_read_mbx - Reads a message from the mailbox
8  *  @hw: pointer to the HW structure
9  *  @msg: The message buffer
10  *  @size: Length of buffer
11  *  @mbx_id: id of mailbox to read
12  *  @unlock: skip locking or not
13  *
14  *  returns SUCCESS if it successfully read message from buffer
15  **/
16 s32 igb_read_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id,
17 		 bool unlock)
18 {
19 	struct e1000_mbx_info *mbx = &hw->mbx;
20 	s32 ret_val = -E1000_ERR_MBX;
21 
22 	/* limit read to size of mailbox */
23 	if (size > mbx->size)
24 		size = mbx->size;
25 
26 	if (mbx->ops.read)
27 		ret_val = mbx->ops.read(hw, msg, size, mbx_id, unlock);
28 
29 	return ret_val;
30 }
31 
32 /**
33  *  igb_write_mbx - Write a message to the mailbox
34  *  @hw: pointer to the HW structure
35  *  @msg: The message buffer
36  *  @size: Length of buffer
37  *  @mbx_id: id of mailbox to write
38  *
39  *  returns SUCCESS if it successfully copied message into the buffer
40  **/
41 s32 igb_write_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id)
42 {
43 	struct e1000_mbx_info *mbx = &hw->mbx;
44 	s32 ret_val = 0;
45 
46 	if (size > mbx->size)
47 		ret_val = -E1000_ERR_MBX;
48 
49 	else if (mbx->ops.write)
50 		ret_val = mbx->ops.write(hw, msg, size, mbx_id);
51 
52 	return ret_val;
53 }
54 
55 /**
56  *  igb_check_for_msg - checks to see if someone sent us mail
57  *  @hw: pointer to the HW structure
58  *  @mbx_id: id of mailbox to check
59  *
60  *  returns SUCCESS if the Status bit was found or else ERR_MBX
61  **/
62 s32 igb_check_for_msg(struct e1000_hw *hw, u16 mbx_id)
63 {
64 	struct e1000_mbx_info *mbx = &hw->mbx;
65 	s32 ret_val = -E1000_ERR_MBX;
66 
67 	if (mbx->ops.check_for_msg)
68 		ret_val = mbx->ops.check_for_msg(hw, mbx_id);
69 
70 	return ret_val;
71 }
72 
73 /**
74  *  igb_check_for_ack - checks to see if someone sent us ACK
75  *  @hw: pointer to the HW structure
76  *  @mbx_id: id of mailbox to check
77  *
78  *  returns SUCCESS if the Status bit was found or else ERR_MBX
79  **/
80 s32 igb_check_for_ack(struct e1000_hw *hw, u16 mbx_id)
81 {
82 	struct e1000_mbx_info *mbx = &hw->mbx;
83 	s32 ret_val = -E1000_ERR_MBX;
84 
85 	if (mbx->ops.check_for_ack)
86 		ret_val = mbx->ops.check_for_ack(hw, mbx_id);
87 
88 	return ret_val;
89 }
90 
91 /**
92  *  igb_check_for_rst - checks to see if other side has reset
93  *  @hw: pointer to the HW structure
94  *  @mbx_id: id of mailbox to check
95  *
96  *  returns SUCCESS if the Status bit was found or else ERR_MBX
97  **/
98 s32 igb_check_for_rst(struct e1000_hw *hw, u16 mbx_id)
99 {
100 	struct e1000_mbx_info *mbx = &hw->mbx;
101 	s32 ret_val = -E1000_ERR_MBX;
102 
103 	if (mbx->ops.check_for_rst)
104 		ret_val = mbx->ops.check_for_rst(hw, mbx_id);
105 
106 	return ret_val;
107 }
108 
109 /**
110  *  igb_unlock_mbx - unlock the mailbox
111  *  @hw: pointer to the HW structure
112  *  @mbx_id: id of mailbox to check
113  *
114  *  returns SUCCESS if the mailbox was unlocked or else ERR_MBX
115  **/
116 s32 igb_unlock_mbx(struct e1000_hw *hw, u16 mbx_id)
117 {
118 	struct e1000_mbx_info *mbx = &hw->mbx;
119 	s32 ret_val = -E1000_ERR_MBX;
120 
121 	if (mbx->ops.unlock)
122 		ret_val = mbx->ops.unlock(hw, mbx_id);
123 
124 	return ret_val;
125 }
126 
127 /**
128  *  igb_poll_for_msg - Wait for message notification
129  *  @hw: pointer to the HW structure
130  *  @mbx_id: id of mailbox to write
131  *
132  *  returns SUCCESS if it successfully received a message notification
133  **/
134 static s32 igb_poll_for_msg(struct e1000_hw *hw, u16 mbx_id)
135 {
136 	struct e1000_mbx_info *mbx = &hw->mbx;
137 	int countdown = mbx->timeout;
138 
139 	if (!countdown || !mbx->ops.check_for_msg)
140 		goto out;
141 
142 	while (countdown && mbx->ops.check_for_msg(hw, mbx_id)) {
143 		countdown--;
144 		if (!countdown)
145 			break;
146 		udelay(mbx->usec_delay);
147 	}
148 
149 	/* if we failed, all future posted messages fail until reset */
150 	if (!countdown)
151 		mbx->timeout = 0;
152 out:
153 	return countdown ? 0 : -E1000_ERR_MBX;
154 }
155 
156 /**
157  *  igb_poll_for_ack - Wait for message acknowledgement
158  *  @hw: pointer to the HW structure
159  *  @mbx_id: id of mailbox to write
160  *
161  *  returns SUCCESS if it successfully received a message acknowledgement
162  **/
163 static s32 igb_poll_for_ack(struct e1000_hw *hw, u16 mbx_id)
164 {
165 	struct e1000_mbx_info *mbx = &hw->mbx;
166 	int countdown = mbx->timeout;
167 
168 	if (!countdown || !mbx->ops.check_for_ack)
169 		goto out;
170 
171 	while (countdown && mbx->ops.check_for_ack(hw, mbx_id)) {
172 		countdown--;
173 		if (!countdown)
174 			break;
175 		udelay(mbx->usec_delay);
176 	}
177 
178 	/* if we failed, all future posted messages fail until reset */
179 	if (!countdown)
180 		mbx->timeout = 0;
181 out:
182 	return countdown ? 0 : -E1000_ERR_MBX;
183 }
184 
185 /**
186  *  igb_read_posted_mbx - Wait for message notification and receive message
187  *  @hw: pointer to the HW structure
188  *  @msg: The message buffer
189  *  @size: Length of buffer
190  *  @mbx_id: id of mailbox to write
191  *
192  *  returns SUCCESS if it successfully received a message notification and
193  *  copied it into the receive buffer.
194  **/
195 static s32 igb_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
196 			       u16 mbx_id)
197 {
198 	struct e1000_mbx_info *mbx = &hw->mbx;
199 	s32 ret_val = -E1000_ERR_MBX;
200 
201 	if (!mbx->ops.read)
202 		goto out;
203 
204 	ret_val = igb_poll_for_msg(hw, mbx_id);
205 
206 	if (!ret_val)
207 		ret_val = mbx->ops.read(hw, msg, size, mbx_id, true);
208 out:
209 	return ret_val;
210 }
211 
212 /**
213  *  igb_write_posted_mbx - Write a message to the mailbox, wait for ack
214  *  @hw: pointer to the HW structure
215  *  @msg: The message buffer
216  *  @size: Length of buffer
217  *  @mbx_id: id of mailbox to write
218  *
219  *  returns SUCCESS if it successfully copied message into the buffer and
220  *  received an ack to that message within delay * timeout period
221  **/
222 static s32 igb_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
223 				u16 mbx_id)
224 {
225 	struct e1000_mbx_info *mbx = &hw->mbx;
226 	s32 ret_val = -E1000_ERR_MBX;
227 
228 	/* exit if either we can't write or there isn't a defined timeout */
229 	if (!mbx->ops.write || !mbx->timeout)
230 		goto out;
231 
232 	/* send msg */
233 	ret_val = mbx->ops.write(hw, msg, size, mbx_id);
234 
235 	/* if msg sent wait until we receive an ack */
236 	if (!ret_val)
237 		ret_val = igb_poll_for_ack(hw, mbx_id);
238 out:
239 	return ret_val;
240 }
241 
242 static s32 igb_check_for_bit_pf(struct e1000_hw *hw, u32 mask)
243 {
244 	u32 mbvficr = rd32(E1000_MBVFICR);
245 	s32 ret_val = -E1000_ERR_MBX;
246 
247 	if (mbvficr & mask) {
248 		ret_val = 0;
249 		wr32(E1000_MBVFICR, mask);
250 	}
251 
252 	return ret_val;
253 }
254 
255 /**
256  *  igb_check_for_msg_pf - checks to see if the VF has sent mail
257  *  @hw: pointer to the HW structure
258  *  @vf_number: the VF index
259  *
260  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
261  **/
262 static s32 igb_check_for_msg_pf(struct e1000_hw *hw, u16 vf_number)
263 {
264 	s32 ret_val = -E1000_ERR_MBX;
265 
266 	if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFREQ_VF1 << vf_number)) {
267 		ret_val = 0;
268 		hw->mbx.stats.reqs++;
269 	}
270 
271 	return ret_val;
272 }
273 
274 /**
275  *  igb_check_for_ack_pf - checks to see if the VF has ACKed
276  *  @hw: pointer to the HW structure
277  *  @vf_number: the VF index
278  *
279  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
280  **/
281 static s32 igb_check_for_ack_pf(struct e1000_hw *hw, u16 vf_number)
282 {
283 	s32 ret_val = -E1000_ERR_MBX;
284 
285 	if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFACK_VF1 << vf_number)) {
286 		ret_val = 0;
287 		hw->mbx.stats.acks++;
288 	}
289 
290 	return ret_val;
291 }
292 
293 /**
294  *  igb_check_for_rst_pf - checks to see if the VF has reset
295  *  @hw: pointer to the HW structure
296  *  @vf_number: the VF index
297  *
298  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
299  **/
300 static s32 igb_check_for_rst_pf(struct e1000_hw *hw, u16 vf_number)
301 {
302 	u32 vflre = rd32(E1000_VFLRE);
303 	s32 ret_val = -E1000_ERR_MBX;
304 
305 	if (vflre & BIT(vf_number)) {
306 		ret_val = 0;
307 		wr32(E1000_VFLRE, BIT(vf_number));
308 		hw->mbx.stats.rsts++;
309 	}
310 
311 	return ret_val;
312 }
313 
314 /**
315  *  igb_obtain_mbx_lock_pf - obtain mailbox lock
316  *  @hw: pointer to the HW structure
317  *  @vf_number: the VF index
318  *
319  *  return SUCCESS if we obtained the mailbox lock
320  **/
321 static s32 igb_obtain_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
322 {
323 	s32 ret_val = -E1000_ERR_MBX;
324 	u32 p2v_mailbox;
325 	int count = 10;
326 
327 	do {
328 		/* Take ownership of the buffer */
329 		wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_PFU);
330 
331 		/* reserve mailbox for vf use */
332 		p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
333 		if (p2v_mailbox & E1000_P2VMAILBOX_PFU) {
334 			ret_val = 0;
335 			break;
336 		}
337 		udelay(1000);
338 	} while (count-- > 0);
339 
340 	return ret_val;
341 }
342 
343 /**
344  *  igb_release_mbx_lock_pf - release mailbox lock
345  *  @hw: pointer to the HW structure
346  *  @vf_number: the VF index
347  *
348  *  return SUCCESS if we released the mailbox lock
349  **/
350 static s32 igb_release_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
351 {
352 	u32 p2v_mailbox;
353 
354 	/* drop PF lock of mailbox, if set */
355 	p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
356 	if (p2v_mailbox & E1000_P2VMAILBOX_PFU)
357 		wr32(E1000_P2VMAILBOX(vf_number),
358 		     p2v_mailbox & ~E1000_P2VMAILBOX_PFU);
359 
360 	return 0;
361 }
362 
363 /**
364  *  igb_write_mbx_pf - Places a message in the mailbox
365  *  @hw: pointer to the HW structure
366  *  @msg: The message buffer
367  *  @size: Length of buffer
368  *  @vf_number: the VF index
369  *
370  *  returns SUCCESS if it successfully copied message into the buffer
371  **/
372 static s32 igb_write_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
373 			    u16 vf_number)
374 {
375 	s32 ret_val;
376 	u16 i;
377 
378 	/* lock the mailbox to prevent pf/vf race condition */
379 	ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
380 	if (ret_val)
381 		goto out_no_write;
382 
383 	/* flush msg and acks as we are overwriting the message buffer */
384 	igb_check_for_msg_pf(hw, vf_number);
385 	igb_check_for_ack_pf(hw, vf_number);
386 
387 	/* copy the caller specified message to the mailbox memory buffer */
388 	for (i = 0; i < size; i++)
389 		array_wr32(E1000_VMBMEM(vf_number), i, msg[i]);
390 
391 	/* Interrupt VF to tell it a message has been sent and release buffer*/
392 	wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_STS);
393 
394 	/* update stats */
395 	hw->mbx.stats.msgs_tx++;
396 
397 out_no_write:
398 	return ret_val;
399 
400 }
401 
402 /**
403  *  igb_read_mbx_pf - Read a message from the mailbox
404  *  @hw: pointer to the HW structure
405  *  @msg: The message buffer
406  *  @size: Length of buffer
407  *  @vf_number: the VF index
408  *  @unlock: unlock the mailbox when done?
409  *
410  *  This function copies a message from the mailbox buffer to the caller's
411  *  memory buffer.  The presumption is that the caller knows that there was
412  *  a message due to a VF request so no polling for message is needed.
413  **/
414 static s32 igb_read_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
415 			   u16 vf_number, bool unlock)
416 {
417 	s32 ret_val;
418 	u16 i;
419 
420 	/* lock the mailbox to prevent pf/vf race condition */
421 	ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
422 	if (ret_val)
423 		goto out_no_read;
424 
425 	/* copy the message to the mailbox memory buffer */
426 	for (i = 0; i < size; i++)
427 		msg[i] = array_rd32(E1000_VMBMEM(vf_number), i);
428 
429 	/* Acknowledge the message and release mailbox lock (or not) */
430 	if (unlock)
431 		wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_ACK);
432 	else
433 		wr32(E1000_P2VMAILBOX(vf_number),
434 		     E1000_P2VMAILBOX_ACK | E1000_P2VMAILBOX_PFU);
435 
436 	/* update stats */
437 	hw->mbx.stats.msgs_rx++;
438 
439 out_no_read:
440 	return ret_val;
441 }
442 
443 /**
444  *  e1000_init_mbx_params_pf - set initial values for pf mailbox
445  *  @hw: pointer to the HW structure
446  *
447  *  Initializes the hw->mbx struct to correct values for pf mailbox
448  */
449 s32 igb_init_mbx_params_pf(struct e1000_hw *hw)
450 {
451 	struct e1000_mbx_info *mbx = &hw->mbx;
452 
453 	mbx->timeout = 0;
454 	mbx->usec_delay = 0;
455 
456 	mbx->size = E1000_VFMAILBOX_SIZE;
457 
458 	mbx->ops.read = igb_read_mbx_pf;
459 	mbx->ops.write = igb_write_mbx_pf;
460 	mbx->ops.read_posted = igb_read_posted_mbx;
461 	mbx->ops.write_posted = igb_write_posted_mbx;
462 	mbx->ops.check_for_msg = igb_check_for_msg_pf;
463 	mbx->ops.check_for_ack = igb_check_for_ack_pf;
464 	mbx->ops.check_for_rst = igb_check_for_rst_pf;
465 	mbx->ops.unlock = igb_release_mbx_lock_pf;
466 
467 	mbx->stats.msgs_tx = 0;
468 	mbx->stats.msgs_rx = 0;
469 	mbx->stats.reqs = 0;
470 	mbx->stats.acks = 0;
471 	mbx->stats.rsts = 0;
472 
473 	return 0;
474 }
475 
476