xref: /linux/drivers/net/ethernet/intel/igb/e1000_mbx.c (revision bab2c80e5a6c855657482eac9e97f5f3eedb509a)
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  *
13  *  returns SUCCESS if it successfully read message from buffer
14  **/
15 s32 igb_read_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id,
16 		 bool unlock)
17 {
18 	struct e1000_mbx_info *mbx = &hw->mbx;
19 	s32 ret_val = -E1000_ERR_MBX;
20 
21 	/* limit read to size of mailbox */
22 	if (size > mbx->size)
23 		size = mbx->size;
24 
25 	if (mbx->ops.read)
26 		ret_val = mbx->ops.read(hw, msg, size, mbx_id, unlock);
27 
28 	return ret_val;
29 }
30 
31 /**
32  *  igb_write_mbx - Write a message to the mailbox
33  *  @hw: pointer to the HW structure
34  *  @msg: The message buffer
35  *  @size: Length of buffer
36  *  @mbx_id: id of mailbox to write
37  *
38  *  returns SUCCESS if it successfully copied message into the buffer
39  **/
40 s32 igb_write_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id)
41 {
42 	struct e1000_mbx_info *mbx = &hw->mbx;
43 	s32 ret_val = 0;
44 
45 	if (size > mbx->size)
46 		ret_val = -E1000_ERR_MBX;
47 
48 	else if (mbx->ops.write)
49 		ret_val = mbx->ops.write(hw, msg, size, mbx_id);
50 
51 	return ret_val;
52 }
53 
54 /**
55  *  igb_check_for_msg - checks to see if someone sent us mail
56  *  @hw: pointer to the HW structure
57  *  @mbx_id: id of mailbox to check
58  *
59  *  returns SUCCESS if the Status bit was found or else ERR_MBX
60  **/
61 s32 igb_check_for_msg(struct e1000_hw *hw, u16 mbx_id)
62 {
63 	struct e1000_mbx_info *mbx = &hw->mbx;
64 	s32 ret_val = -E1000_ERR_MBX;
65 
66 	if (mbx->ops.check_for_msg)
67 		ret_val = mbx->ops.check_for_msg(hw, mbx_id);
68 
69 	return ret_val;
70 }
71 
72 /**
73  *  igb_check_for_ack - checks to see if someone sent us ACK
74  *  @hw: pointer to the HW structure
75  *  @mbx_id: id of mailbox to check
76  *
77  *  returns SUCCESS if the Status bit was found or else ERR_MBX
78  **/
79 s32 igb_check_for_ack(struct e1000_hw *hw, u16 mbx_id)
80 {
81 	struct e1000_mbx_info *mbx = &hw->mbx;
82 	s32 ret_val = -E1000_ERR_MBX;
83 
84 	if (mbx->ops.check_for_ack)
85 		ret_val = mbx->ops.check_for_ack(hw, mbx_id);
86 
87 	return ret_val;
88 }
89 
90 /**
91  *  igb_check_for_rst - checks to see if other side has reset
92  *  @hw: pointer to the HW structure
93  *  @mbx_id: id of mailbox to check
94  *
95  *  returns SUCCESS if the Status bit was found or else ERR_MBX
96  **/
97 s32 igb_check_for_rst(struct e1000_hw *hw, u16 mbx_id)
98 {
99 	struct e1000_mbx_info *mbx = &hw->mbx;
100 	s32 ret_val = -E1000_ERR_MBX;
101 
102 	if (mbx->ops.check_for_rst)
103 		ret_val = mbx->ops.check_for_rst(hw, mbx_id);
104 
105 	return ret_val;
106 }
107 
108 /**
109  *  igb_unlock_mbx - unlock the mailbox
110  *  @hw: pointer to the HW structure
111  *  @mbx_id: id of mailbox to check
112  *
113  *  returns SUCCESS if the mailbox was unlocked or else ERR_MBX
114  **/
115 s32 igb_unlock_mbx(struct e1000_hw *hw, u16 mbx_id)
116 {
117 	struct e1000_mbx_info *mbx = &hw->mbx;
118 	s32 ret_val = -E1000_ERR_MBX;
119 
120 	if (mbx->ops.unlock)
121 		ret_val = mbx->ops.unlock(hw, mbx_id);
122 
123 	return ret_val;
124 }
125 
126 /**
127  *  igb_poll_for_msg - Wait for message notification
128  *  @hw: pointer to the HW structure
129  *  @mbx_id: id of mailbox to write
130  *
131  *  returns SUCCESS if it successfully received a message notification
132  **/
133 static s32 igb_poll_for_msg(struct e1000_hw *hw, u16 mbx_id)
134 {
135 	struct e1000_mbx_info *mbx = &hw->mbx;
136 	int countdown = mbx->timeout;
137 
138 	if (!countdown || !mbx->ops.check_for_msg)
139 		goto out;
140 
141 	while (countdown && mbx->ops.check_for_msg(hw, mbx_id)) {
142 		countdown--;
143 		if (!countdown)
144 			break;
145 		udelay(mbx->usec_delay);
146 	}
147 
148 	/* if we failed, all future posted messages fail until reset */
149 	if (!countdown)
150 		mbx->timeout = 0;
151 out:
152 	return countdown ? 0 : -E1000_ERR_MBX;
153 }
154 
155 /**
156  *  igb_poll_for_ack - Wait for message acknowledgement
157  *  @hw: pointer to the HW structure
158  *  @mbx_id: id of mailbox to write
159  *
160  *  returns SUCCESS if it successfully received a message acknowledgement
161  **/
162 static s32 igb_poll_for_ack(struct e1000_hw *hw, u16 mbx_id)
163 {
164 	struct e1000_mbx_info *mbx = &hw->mbx;
165 	int countdown = mbx->timeout;
166 
167 	if (!countdown || !mbx->ops.check_for_ack)
168 		goto out;
169 
170 	while (countdown && mbx->ops.check_for_ack(hw, mbx_id)) {
171 		countdown--;
172 		if (!countdown)
173 			break;
174 		udelay(mbx->usec_delay);
175 	}
176 
177 	/* if we failed, all future posted messages fail until reset */
178 	if (!countdown)
179 		mbx->timeout = 0;
180 out:
181 	return countdown ? 0 : -E1000_ERR_MBX;
182 }
183 
184 /**
185  *  igb_read_posted_mbx - Wait for message notification and receive message
186  *  @hw: pointer to the HW structure
187  *  @msg: The message buffer
188  *  @size: Length of buffer
189  *  @mbx_id: id of mailbox to write
190  *
191  *  returns SUCCESS if it successfully received a message notification and
192  *  copied it into the receive buffer.
193  **/
194 static s32 igb_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
195 			       u16 mbx_id)
196 {
197 	struct e1000_mbx_info *mbx = &hw->mbx;
198 	s32 ret_val = -E1000_ERR_MBX;
199 
200 	if (!mbx->ops.read)
201 		goto out;
202 
203 	ret_val = igb_poll_for_msg(hw, mbx_id);
204 
205 	if (!ret_val)
206 		ret_val = mbx->ops.read(hw, msg, size, mbx_id, true);
207 out:
208 	return ret_val;
209 }
210 
211 /**
212  *  igb_write_posted_mbx - Write a message to the mailbox, wait for ack
213  *  @hw: pointer to the HW structure
214  *  @msg: The message buffer
215  *  @size: Length of buffer
216  *  @mbx_id: id of mailbox to write
217  *
218  *  returns SUCCESS if it successfully copied message into the buffer and
219  *  received an ack to that message within delay * timeout period
220  **/
221 static s32 igb_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
222 				u16 mbx_id)
223 {
224 	struct e1000_mbx_info *mbx = &hw->mbx;
225 	s32 ret_val = -E1000_ERR_MBX;
226 
227 	/* exit if either we can't write or there isn't a defined timeout */
228 	if (!mbx->ops.write || !mbx->timeout)
229 		goto out;
230 
231 	/* send msg */
232 	ret_val = mbx->ops.write(hw, msg, size, mbx_id);
233 
234 	/* if msg sent wait until we receive an ack */
235 	if (!ret_val)
236 		ret_val = igb_poll_for_ack(hw, mbx_id);
237 out:
238 	return ret_val;
239 }
240 
241 static s32 igb_check_for_bit_pf(struct e1000_hw *hw, u32 mask)
242 {
243 	u32 mbvficr = rd32(E1000_MBVFICR);
244 	s32 ret_val = -E1000_ERR_MBX;
245 
246 	if (mbvficr & mask) {
247 		ret_val = 0;
248 		wr32(E1000_MBVFICR, mask);
249 	}
250 
251 	return ret_val;
252 }
253 
254 /**
255  *  igb_check_for_msg_pf - checks to see if the VF has sent mail
256  *  @hw: pointer to the HW structure
257  *  @vf_number: the VF index
258  *
259  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
260  **/
261 static s32 igb_check_for_msg_pf(struct e1000_hw *hw, u16 vf_number)
262 {
263 	s32 ret_val = -E1000_ERR_MBX;
264 
265 	if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFREQ_VF1 << vf_number)) {
266 		ret_val = 0;
267 		hw->mbx.stats.reqs++;
268 	}
269 
270 	return ret_val;
271 }
272 
273 /**
274  *  igb_check_for_ack_pf - checks to see if the VF has ACKed
275  *  @hw: pointer to the HW structure
276  *  @vf_number: the VF index
277  *
278  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
279  **/
280 static s32 igb_check_for_ack_pf(struct e1000_hw *hw, u16 vf_number)
281 {
282 	s32 ret_val = -E1000_ERR_MBX;
283 
284 	if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFACK_VF1 << vf_number)) {
285 		ret_val = 0;
286 		hw->mbx.stats.acks++;
287 	}
288 
289 	return ret_val;
290 }
291 
292 /**
293  *  igb_check_for_rst_pf - checks to see if the VF has reset
294  *  @hw: pointer to the HW structure
295  *  @vf_number: the VF index
296  *
297  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
298  **/
299 static s32 igb_check_for_rst_pf(struct e1000_hw *hw, u16 vf_number)
300 {
301 	u32 vflre = rd32(E1000_VFLRE);
302 	s32 ret_val = -E1000_ERR_MBX;
303 
304 	if (vflre & BIT(vf_number)) {
305 		ret_val = 0;
306 		wr32(E1000_VFLRE, BIT(vf_number));
307 		hw->mbx.stats.rsts++;
308 	}
309 
310 	return ret_val;
311 }
312 
313 /**
314  *  igb_obtain_mbx_lock_pf - obtain mailbox lock
315  *  @hw: pointer to the HW structure
316  *  @vf_number: the VF index
317  *
318  *  return SUCCESS if we obtained the mailbox lock
319  **/
320 static s32 igb_obtain_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
321 {
322 	s32 ret_val = -E1000_ERR_MBX;
323 	u32 p2v_mailbox;
324 	int count = 10;
325 
326 	do {
327 		/* Take ownership of the buffer */
328 		wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_PFU);
329 
330 		/* reserve mailbox for vf use */
331 		p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
332 		if (p2v_mailbox & E1000_P2VMAILBOX_PFU) {
333 			ret_val = 0;
334 			break;
335 		}
336 		udelay(1000);
337 	} while (count-- > 0);
338 
339 	return ret_val;
340 }
341 
342 /**
343  *  igb_release_mbx_lock_pf - release mailbox lock
344  *  @hw: pointer to the HW structure
345  *  @vf_number: the VF index
346  *
347  *  return SUCCESS if we released the mailbox lock
348  **/
349 static s32 igb_release_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
350 {
351 	u32 p2v_mailbox;
352 
353 	/* drop PF lock of mailbox, if set */
354 	p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
355 	if (p2v_mailbox & E1000_P2VMAILBOX_PFU)
356 		wr32(E1000_P2VMAILBOX(vf_number),
357 		     p2v_mailbox & ~E1000_P2VMAILBOX_PFU);
358 
359 	return 0;
360 }
361 
362 /**
363  *  igb_write_mbx_pf - Places a message in the mailbox
364  *  @hw: pointer to the HW structure
365  *  @msg: The message buffer
366  *  @size: Length of buffer
367  *  @vf_number: the VF index
368  *
369  *  returns SUCCESS if it successfully copied message into the buffer
370  **/
371 static s32 igb_write_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
372 			    u16 vf_number)
373 {
374 	s32 ret_val;
375 	u16 i;
376 
377 	/* lock the mailbox to prevent pf/vf race condition */
378 	ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
379 	if (ret_val)
380 		goto out_no_write;
381 
382 	/* flush msg and acks as we are overwriting the message buffer */
383 	igb_check_for_msg_pf(hw, vf_number);
384 	igb_check_for_ack_pf(hw, vf_number);
385 
386 	/* copy the caller specified message to the mailbox memory buffer */
387 	for (i = 0; i < size; i++)
388 		array_wr32(E1000_VMBMEM(vf_number), i, msg[i]);
389 
390 	/* Interrupt VF to tell it a message has been sent and release buffer*/
391 	wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_STS);
392 
393 	/* update stats */
394 	hw->mbx.stats.msgs_tx++;
395 
396 out_no_write:
397 	return ret_val;
398 
399 }
400 
401 /**
402  *  igb_read_mbx_pf - Read a message from the mailbox
403  *  @hw: pointer to the HW structure
404  *  @msg: The message buffer
405  *  @size: Length of buffer
406  *  @vf_number: the VF index
407  *  @unlock: unlock the mailbox when done?
408  *
409  *  This function copies a message from the mailbox buffer to the caller's
410  *  memory buffer.  The presumption is that the caller knows that there was
411  *  a message due to a VF request so no polling for message is needed.
412  **/
413 static s32 igb_read_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
414 			   u16 vf_number, bool unlock)
415 {
416 	s32 ret_val;
417 	u16 i;
418 
419 	/* lock the mailbox to prevent pf/vf race condition */
420 	ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
421 	if (ret_val)
422 		goto out_no_read;
423 
424 	/* copy the message to the mailbox memory buffer */
425 	for (i = 0; i < size; i++)
426 		msg[i] = array_rd32(E1000_VMBMEM(vf_number), i);
427 
428 	/* Acknowledge the message and release mailbox lock (or not) */
429 	if (unlock)
430 		wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_ACK);
431 	else
432 		wr32(E1000_P2VMAILBOX(vf_number),
433 		     E1000_P2VMAILBOX_ACK | E1000_P2VMAILBOX_PFU);
434 
435 	/* update stats */
436 	hw->mbx.stats.msgs_rx++;
437 
438 out_no_read:
439 	return ret_val;
440 }
441 
442 /**
443  *  e1000_init_mbx_params_pf - set initial values for pf mailbox
444  *  @hw: pointer to the HW structure
445  *
446  *  Initializes the hw->mbx struct to correct values for pf mailbox
447  */
448 s32 igb_init_mbx_params_pf(struct e1000_hw *hw)
449 {
450 	struct e1000_mbx_info *mbx = &hw->mbx;
451 
452 	mbx->timeout = 0;
453 	mbx->usec_delay = 0;
454 
455 	mbx->size = E1000_VFMAILBOX_SIZE;
456 
457 	mbx->ops.read = igb_read_mbx_pf;
458 	mbx->ops.write = igb_write_mbx_pf;
459 	mbx->ops.read_posted = igb_read_posted_mbx;
460 	mbx->ops.write_posted = igb_write_posted_mbx;
461 	mbx->ops.check_for_msg = igb_check_for_msg_pf;
462 	mbx->ops.check_for_ack = igb_check_for_ack_pf;
463 	mbx->ops.check_for_rst = igb_check_for_rst_pf;
464 	mbx->ops.unlock = igb_release_mbx_lock_pf;
465 
466 	mbx->stats.msgs_tx = 0;
467 	mbx->stats.msgs_rx = 0;
468 	mbx->stats.reqs = 0;
469 	mbx->stats.acks = 0;
470 	mbx->stats.rsts = 0;
471 
472 	return 0;
473 }
474 
475