1// SPDX-License-Identifier: GPL-2.0
2/* Copyright(c) 1999 - 2018 Intel Corporation. */
3
4#include "mbx.h"
5#include "ixgbevf.h"
6
7/**
8 *  ixgbevf_poll_for_msg - Wait for message notification
9 *  @hw: pointer to the HW structure
10 *
11 *  returns 0 if it successfully received a message notification
12 **/
13static s32 ixgbevf_poll_for_msg(struct ixgbe_hw *hw)
14{
15	struct ixgbe_mbx_info *mbx = &hw->mbx;
16	int countdown = mbx->timeout;
17
18	if (!countdown || !mbx->ops.check_for_msg)
19		return IXGBE_ERR_CONFIG;
20
21	while (countdown && mbx->ops.check_for_msg(hw)) {
22		countdown--;
23		udelay(mbx->udelay);
24	}
25
26	return countdown ? 0 : IXGBE_ERR_TIMEOUT;
27}
28
29/**
30 *  ixgbevf_poll_for_ack - Wait for message acknowledgment
31 *  @hw: pointer to the HW structure
32 *
33 *  returns 0 if it successfully received a message acknowledgment
34 **/
35static s32 ixgbevf_poll_for_ack(struct ixgbe_hw *hw)
36{
37	struct ixgbe_mbx_info *mbx = &hw->mbx;
38	int countdown = mbx->timeout;
39
40	if (!countdown || !mbx->ops.check_for_ack)
41		return IXGBE_ERR_CONFIG;
42
43	while (countdown && mbx->ops.check_for_ack(hw)) {
44		countdown--;
45		udelay(mbx->udelay);
46	}
47
48	return countdown ? 0 : IXGBE_ERR_TIMEOUT;
49}
50
51/**
52 * ixgbevf_read_mailbox_vf - read VF's mailbox register
53 * @hw: pointer to the HW structure
54 *
55 * This function is used to read the mailbox register dedicated for VF without
56 * losing the read to clear status bits.
57 **/
58static u32 ixgbevf_read_mailbox_vf(struct ixgbe_hw *hw)
59{
60	u32 vf_mailbox = IXGBE_READ_REG(hw, IXGBE_VFMAILBOX);
61
62	vf_mailbox |= hw->mbx.vf_mailbox;
63	hw->mbx.vf_mailbox |= vf_mailbox & IXGBE_VFMAILBOX_R2C_BITS;
64
65	return vf_mailbox;
66}
67
68/**
69 * ixgbevf_clear_msg_vf - clear PF status bit
70 * @hw: pointer to the HW structure
71 *
72 * This function is used to clear PFSTS bit in the VFMAILBOX register
73 **/
74static void ixgbevf_clear_msg_vf(struct ixgbe_hw *hw)
75{
76	u32 vf_mailbox = ixgbevf_read_mailbox_vf(hw);
77
78	if (vf_mailbox & IXGBE_VFMAILBOX_PFSTS) {
79		hw->mbx.stats.reqs++;
80		hw->mbx.vf_mailbox &= ~IXGBE_VFMAILBOX_PFSTS;
81	}
82}
83
84/**
85 * ixgbevf_clear_ack_vf - clear PF ACK bit
86 * @hw: pointer to the HW structure
87 *
88 * This function is used to clear PFACK bit in the VFMAILBOX register
89 **/
90static void ixgbevf_clear_ack_vf(struct ixgbe_hw *hw)
91{
92	u32 vf_mailbox = ixgbevf_read_mailbox_vf(hw);
93
94	if (vf_mailbox & IXGBE_VFMAILBOX_PFACK) {
95		hw->mbx.stats.acks++;
96		hw->mbx.vf_mailbox &= ~IXGBE_VFMAILBOX_PFACK;
97	}
98}
99
100/**
101 * ixgbevf_clear_rst_vf - clear PF reset bit
102 * @hw: pointer to the HW structure
103 *
104 * This function is used to clear reset indication and reset done bit in
105 * VFMAILBOX register after reset the shared resources and the reset sequence.
106 **/
107static void ixgbevf_clear_rst_vf(struct ixgbe_hw *hw)
108{
109	u32 vf_mailbox = ixgbevf_read_mailbox_vf(hw);
110
111	if (vf_mailbox & (IXGBE_VFMAILBOX_RSTI | IXGBE_VFMAILBOX_RSTD)) {
112		hw->mbx.stats.rsts++;
113		hw->mbx.vf_mailbox &= ~(IXGBE_VFMAILBOX_RSTI |
114					IXGBE_VFMAILBOX_RSTD);
115	}
116}
117
118/**
119 *  ixgbevf_check_for_bit_vf - Determine if a status bit was set
120 *  @hw: pointer to the HW structure
121 *  @mask: bitmask for bits to be tested and cleared
122 *
123 *  This function is used to check for the read to clear bits within
124 *  the V2P mailbox.
125 **/
126static s32 ixgbevf_check_for_bit_vf(struct ixgbe_hw *hw, u32 mask)
127{
128	u32 vf_mailbox = ixgbevf_read_mailbox_vf(hw);
129	s32 ret_val = IXGBE_ERR_MBX;
130
131	if (vf_mailbox & mask)
132		ret_val = 0;
133
134	return ret_val;
135}
136
137/**
138 *  ixgbevf_check_for_msg_vf - checks to see if the PF has sent mail
139 *  @hw: pointer to the HW structure
140 *
141 *  returns 0 if the PF has set the Status bit or else ERR_MBX
142 **/
143static s32 ixgbevf_check_for_msg_vf(struct ixgbe_hw *hw)
144{
145	s32 ret_val = IXGBE_ERR_MBX;
146
147	if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFSTS)) {
148		ret_val = 0;
149		hw->mbx.stats.reqs++;
150	}
151
152	return ret_val;
153}
154
155/**
156 *  ixgbevf_check_for_ack_vf - checks to see if the PF has ACK'd
157 *  @hw: pointer to the HW structure
158 *
159 *  returns 0 if the PF has set the ACK bit or else ERR_MBX
160 **/
161static s32 ixgbevf_check_for_ack_vf(struct ixgbe_hw *hw)
162{
163	s32 ret_val = IXGBE_ERR_MBX;
164
165	if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFACK)) {
166		ret_val = 0;
167		ixgbevf_clear_ack_vf(hw);
168		hw->mbx.stats.acks++;
169	}
170
171	return ret_val;
172}
173
174/**
175 *  ixgbevf_check_for_rst_vf - checks to see if the PF has reset
176 *  @hw: pointer to the HW structure
177 *
178 *  returns true if the PF has set the reset done bit or else false
179 **/
180static s32 ixgbevf_check_for_rst_vf(struct ixgbe_hw *hw)
181{
182	s32 ret_val = IXGBE_ERR_MBX;
183
184	if (!ixgbevf_check_for_bit_vf(hw, (IXGBE_VFMAILBOX_RSTD |
185					   IXGBE_VFMAILBOX_RSTI))) {
186		ret_val = 0;
187		ixgbevf_clear_rst_vf(hw);
188		hw->mbx.stats.rsts++;
189	}
190
191	return ret_val;
192}
193
194/**
195 *  ixgbevf_obtain_mbx_lock_vf - obtain mailbox lock
196 *  @hw: pointer to the HW structure
197 *
198 *  return 0 if we obtained the mailbox lock
199 **/
200static s32 ixgbevf_obtain_mbx_lock_vf(struct ixgbe_hw *hw)
201{
202	struct ixgbe_mbx_info *mbx = &hw->mbx;
203	s32 ret_val = IXGBE_ERR_CONFIG;
204	int countdown = mbx->timeout;
205	u32 vf_mailbox;
206
207	if (!mbx->timeout)
208		return ret_val;
209
210	while (countdown--) {
211		/* Reserve mailbox for VF use */
212		vf_mailbox = ixgbevf_read_mailbox_vf(hw);
213		vf_mailbox |= IXGBE_VFMAILBOX_VFU;
214		IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, vf_mailbox);
215
216		/* Verify that VF is the owner of the lock */
217		if (ixgbevf_read_mailbox_vf(hw) & IXGBE_VFMAILBOX_VFU) {
218			ret_val = 0;
219			break;
220		}
221
222		/* Wait a bit before trying again */
223		udelay(mbx->udelay);
224	}
225
226	if (ret_val)
227		ret_val = IXGBE_ERR_TIMEOUT;
228
229	return ret_val;
230}
231
232/**
233 * ixgbevf_release_mbx_lock_vf - release mailbox lock
234 * @hw: pointer to the HW structure
235 **/
236static void ixgbevf_release_mbx_lock_vf(struct ixgbe_hw *hw)
237{
238	u32 vf_mailbox;
239
240	/* Return ownership of the buffer */
241	vf_mailbox = ixgbevf_read_mailbox_vf(hw);
242	vf_mailbox &= ~IXGBE_VFMAILBOX_VFU;
243	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, vf_mailbox);
244}
245
246/**
247 * ixgbevf_release_mbx_lock_vf_legacy - release mailbox lock
248 * @hw: pointer to the HW structure
249 **/
250static void ixgbevf_release_mbx_lock_vf_legacy(struct ixgbe_hw *__always_unused hw)
251{
252}
253
254/**
255 *  ixgbevf_write_mbx_vf - Write a message to the mailbox
256 *  @hw: pointer to the HW structure
257 *  @msg: The message buffer
258 *  @size: Length of buffer
259 *
260 *  returns 0 if it successfully copied message into the buffer
261 **/
262static s32 ixgbevf_write_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
263{
264	u32 vf_mailbox;
265	s32 ret_val;
266	u16 i;
267
268	/* lock the mailbox to prevent PF/VF race condition */
269	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
270	if (ret_val)
271		goto out_no_write;
272
273	/* flush msg and acks as we are overwriting the message buffer */
274	ixgbevf_clear_msg_vf(hw);
275	ixgbevf_clear_ack_vf(hw);
276
277	/* copy the caller specified message to the mailbox memory buffer */
278	for (i = 0; i < size; i++)
279		IXGBE_WRITE_REG_ARRAY(hw, IXGBE_VFMBMEM, i, msg[i]);
280
281	/* update stats */
282	hw->mbx.stats.msgs_tx++;
283
284	/* interrupt the PF to tell it a message has been sent */
285	vf_mailbox = ixgbevf_read_mailbox_vf(hw);
286	vf_mailbox |= IXGBE_VFMAILBOX_REQ;
287	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, vf_mailbox);
288
289	/* if msg sent wait until we receive an ack */
290	ret_val = ixgbevf_poll_for_ack(hw);
291
292out_no_write:
293	hw->mbx.ops.release(hw);
294
295	return ret_val;
296}
297
298/**
299 *  ixgbevf_write_mbx_vf_legacy - Write a message to the mailbox
300 *  @hw: pointer to the HW structure
301 *  @msg: The message buffer
302 *  @size: Length of buffer
303 *
304 *  returns 0 if it successfully copied message into the buffer
305 **/
306static s32 ixgbevf_write_mbx_vf_legacy(struct ixgbe_hw *hw, u32 *msg, u16 size)
307{
308	s32 ret_val;
309	u16 i;
310
311	/* lock the mailbox to prevent PF/VF race condition */
312	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
313	if (ret_val)
314		goto out_no_write;
315
316	/* flush msg and acks as we are overwriting the message buffer */
317	ixgbevf_check_for_msg_vf(hw);
318	ixgbevf_clear_msg_vf(hw);
319	ixgbevf_check_for_ack_vf(hw);
320	ixgbevf_clear_ack_vf(hw);
321
322	/* copy the caller specified message to the mailbox memory buffer */
323	for (i = 0; i < size; i++)
324		IXGBE_WRITE_REG_ARRAY(hw, IXGBE_VFMBMEM, i, msg[i]);
325
326	/* update stats */
327	hw->mbx.stats.msgs_tx++;
328
329	/* Drop VFU and interrupt the PF to tell it a message has been sent */
330	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_REQ);
331
332out_no_write:
333	return ret_val;
334}
335
336/**
337 *  ixgbevf_read_mbx_vf - Reads a message from the inbox intended for VF
338 *  @hw: pointer to the HW structure
339 *  @msg: The message buffer
340 *  @size: Length of buffer
341 *
342 *  returns 0 if it successfully read message from buffer
343 **/
344static s32 ixgbevf_read_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
345{
346	u32 vf_mailbox;
347	s32 ret_val;
348	u16 i;
349
350	/* check if there is a message from PF */
351	ret_val = ixgbevf_check_for_msg_vf(hw);
352	if (ret_val)
353		return ret_val;
354
355	ixgbevf_clear_msg_vf(hw);
356
357	/* copy the message from the mailbox memory buffer */
358	for (i = 0; i < size; i++)
359		msg[i] = IXGBE_READ_REG_ARRAY(hw, IXGBE_VFMBMEM, i);
360
361	/* Acknowledge receipt */
362	vf_mailbox = ixgbevf_read_mailbox_vf(hw);
363	vf_mailbox |= IXGBE_VFMAILBOX_ACK;
364	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, vf_mailbox);
365
366	/* update stats */
367	hw->mbx.stats.msgs_rx++;
368
369	return ret_val;
370}
371
372/**
373 *  ixgbevf_read_mbx_vf_legacy - Reads a message from the inbox intended for VF
374 *  @hw: pointer to the HW structure
375 *  @msg: The message buffer
376 *  @size: Length of buffer
377 *
378 *  returns 0 if it successfully read message from buffer
379 **/
380static s32 ixgbevf_read_mbx_vf_legacy(struct ixgbe_hw *hw, u32 *msg, u16 size)
381{
382	s32 ret_val = 0;
383	u16 i;
384
385	/* lock the mailbox to prevent PF/VF race condition */
386	ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
387	if (ret_val)
388		goto out_no_read;
389
390	/* copy the message from the mailbox memory buffer */
391	for (i = 0; i < size; i++)
392		msg[i] = IXGBE_READ_REG_ARRAY(hw, IXGBE_VFMBMEM, i);
393
394	/* Acknowledge receipt and release mailbox, then we're done */
395	IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_ACK);
396
397	/* update stats */
398	hw->mbx.stats.msgs_rx++;
399
400out_no_read:
401	return ret_val;
402}
403
404/**
405 *  ixgbevf_init_mbx_params_vf - set initial values for VF mailbox
406 *  @hw: pointer to the HW structure
407 *
408 *  Initializes the hw->mbx struct to correct values for VF mailbox
409 */
410static s32 ixgbevf_init_mbx_params_vf(struct ixgbe_hw *hw)
411{
412	struct ixgbe_mbx_info *mbx = &hw->mbx;
413
414	/* start mailbox as timed out and let the reset_hw call set the timeout
415	 * value to begin communications
416	 */
417	mbx->timeout = IXGBE_VF_MBX_INIT_TIMEOUT;
418	mbx->udelay = IXGBE_VF_MBX_INIT_DELAY;
419
420	mbx->size = IXGBE_VFMAILBOX_SIZE;
421
422	mbx->stats.msgs_tx = 0;
423	mbx->stats.msgs_rx = 0;
424	mbx->stats.reqs = 0;
425	mbx->stats.acks = 0;
426	mbx->stats.rsts = 0;
427
428	return 0;
429}
430
431/**
432 * ixgbevf_poll_mbx - Wait for message and read it from the mailbox
433 * @hw: pointer to the HW structure
434 * @msg: The message buffer
435 * @size: Length of buffer
436 *
437 * returns 0 if it successfully read message from buffer
438 **/
439s32 ixgbevf_poll_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
440{
441	struct ixgbe_mbx_info *mbx = &hw->mbx;
442	s32 ret_val = IXGBE_ERR_CONFIG;
443
444	if (!mbx->ops.read || !mbx->ops.check_for_msg || !mbx->timeout)
445		return ret_val;
446
447	/* limit read to size of mailbox */
448	if (size > mbx->size)
449		size = mbx->size;
450
451	ret_val = ixgbevf_poll_for_msg(hw);
452	/* if ack received read message, otherwise we timed out */
453	if (!ret_val)
454		ret_val = mbx->ops.read(hw, msg, size);
455
456	return ret_val;
457}
458
459/**
460 * ixgbevf_write_mbx - Write a message to the mailbox and wait for ACK
461 * @hw: pointer to the HW structure
462 * @msg: The message buffer
463 * @size: Length of buffer
464 *
465 * returns 0 if it successfully copied message into the buffer and
466 * received an ACK to that message within specified period
467 **/
468s32 ixgbevf_write_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
469{
470	struct ixgbe_mbx_info *mbx = &hw->mbx;
471	s32 ret_val = IXGBE_ERR_CONFIG;
472
473	/**
474	 * exit if either we can't write, release
475	 * or there is no timeout defined
476	 */
477	if (!mbx->ops.write || !mbx->ops.check_for_ack || !mbx->ops.release ||
478	    !mbx->timeout)
479		return ret_val;
480
481	if (size > mbx->size)
482		ret_val = IXGBE_ERR_PARAM;
483	else
484		ret_val = mbx->ops.write(hw, msg, size);
485
486	return ret_val;
487}
488
489const struct ixgbe_mbx_operations ixgbevf_mbx_ops = {
490	.init_params	= ixgbevf_init_mbx_params_vf,
491	.release	= ixgbevf_release_mbx_lock_vf,
492	.read		= ixgbevf_read_mbx_vf,
493	.write		= ixgbevf_write_mbx_vf,
494	.check_for_msg	= ixgbevf_check_for_msg_vf,
495	.check_for_ack	= ixgbevf_check_for_ack_vf,
496	.check_for_rst	= ixgbevf_check_for_rst_vf,
497};
498
499const struct ixgbe_mbx_operations ixgbevf_mbx_ops_legacy = {
500	.init_params	= ixgbevf_init_mbx_params_vf,
501	.release	= ixgbevf_release_mbx_lock_vf_legacy,
502	.read		= ixgbevf_read_mbx_vf_legacy,
503	.write		= ixgbevf_write_mbx_vf_legacy,
504	.check_for_msg	= ixgbevf_check_for_msg_vf,
505	.check_for_ack	= ixgbevf_check_for_ack_vf,
506	.check_for_rst	= ixgbevf_check_for_rst_vf,
507};
508
509/* Mailbox operations when running on Hyper-V.
510 * On Hyper-V, PF/VF communication is not through the
511 * hardware mailbox; this communication is through
512 * a software mediated path.
513 * Most mail box operations are noop while running on
514 * Hyper-V.
515 */
516const struct ixgbe_mbx_operations ixgbevf_hv_mbx_ops = {
517	.init_params	= ixgbevf_init_mbx_params_vf,
518	.check_for_rst	= ixgbevf_check_for_rst_vf,
519};
520