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 **/
 15s32 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 **/
 40s32 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 **/
 61s32 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 **/
 79s32 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 **/
 97s32 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 **/
115s32 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 **/
133static 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;
151out:
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 **/
162static 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;
180out:
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 **/
194static 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);
207out:
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 **/
221static 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);
237out:
238	return ret_val;
239}
240
241static 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 **/
261static 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 **/
280static 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 **/
299static 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 **/
320static 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 **/
349static 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 **/
371static 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
396out_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 **/
413static 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
438out_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 */
448s32 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