1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2009 - 2018 Intel Corporation. */
3 
4 #include "mbx.h"
5 
6 /**
7  *  e1000_poll_for_msg - Wait for message notification
8  *  @hw: pointer to the HW structure
9  *
10  *  returns SUCCESS if it successfully received a message notification
11  **/
12 static s32 e1000_poll_for_msg(struct e1000_hw *hw)
13 {
14 	struct e1000_mbx_info *mbx = &hw->mbx;
15 	int countdown = mbx->timeout;
16 
17 	if (!mbx->ops.check_for_msg)
18 		goto out;
19 
20 	while (countdown && mbx->ops.check_for_msg(hw)) {
21 		countdown--;
22 		udelay(mbx->usec_delay);
23 	}
24 
25 	/* if we failed, all future posted messages fail until reset */
26 	if (!countdown)
27 		mbx->timeout = 0;
28 out:
29 	return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
30 }
31 
32 /**
33  *  e1000_poll_for_ack - Wait for message acknowledgment
34  *  @hw: pointer to the HW structure
35  *
36  *  returns SUCCESS if it successfully received a message acknowledgment
37  **/
38 static s32 e1000_poll_for_ack(struct e1000_hw *hw)
39 {
40 	struct e1000_mbx_info *mbx = &hw->mbx;
41 	int countdown = mbx->timeout;
42 
43 	if (!mbx->ops.check_for_ack)
44 		goto out;
45 
46 	while (countdown && mbx->ops.check_for_ack(hw)) {
47 		countdown--;
48 		udelay(mbx->usec_delay);
49 	}
50 
51 	/* if we failed, all future posted messages fail until reset */
52 	if (!countdown)
53 		mbx->timeout = 0;
54 out:
55 	return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
56 }
57 
58 /**
59  *  e1000_read_posted_mbx - Wait for message notification and receive message
60  *  @hw: pointer to the HW structure
61  *  @msg: The message buffer
62  *  @size: Length of buffer
63  *
64  *  returns SUCCESS if it successfully received a message notification and
65  *  copied it into the receive buffer.
66  **/
67 static s32 e1000_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
68 {
69 	struct e1000_mbx_info *mbx = &hw->mbx;
70 	s32 ret_val = -E1000_ERR_MBX;
71 
72 	if (!mbx->ops.read)
73 		goto out;
74 
75 	ret_val = e1000_poll_for_msg(hw);
76 
77 	/* if ack received read message, otherwise we timed out */
78 	if (!ret_val)
79 		ret_val = mbx->ops.read(hw, msg, size);
80 out:
81 	return ret_val;
82 }
83 
84 /**
85  *  e1000_write_posted_mbx - Write a message to the mailbox, wait for ack
86  *  @hw: pointer to the HW structure
87  *  @msg: The message buffer
88  *  @size: Length of buffer
89  *
90  *  returns SUCCESS if it successfully copied message into the buffer and
91  *  received an ack to that message within delay * timeout period
92  **/
93 static s32 e1000_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
94 {
95 	struct e1000_mbx_info *mbx = &hw->mbx;
96 	s32 ret_val = -E1000_ERR_MBX;
97 
98 	/* exit if we either can't write or there isn't a defined timeout */
99 	if (!mbx->ops.write || !mbx->timeout)
100 		goto out;
101 
102 	/* send msg*/
103 	ret_val = mbx->ops.write(hw, msg, size);
104 
105 	/* if msg sent wait until we receive an ack */
106 	if (!ret_val)
107 		ret_val = e1000_poll_for_ack(hw);
108 out:
109 	return ret_val;
110 }
111 
112 /**
113  *  e1000_read_v2p_mailbox - read v2p mailbox
114  *  @hw: pointer to the HW structure
115  *
116  *  This function is used to read the v2p mailbox without losing the read to
117  *  clear status bits.
118  **/
119 static u32 e1000_read_v2p_mailbox(struct e1000_hw *hw)
120 {
121 	u32 v2p_mailbox = er32(V2PMAILBOX(0));
122 
123 	v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
124 	hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
125 
126 	return v2p_mailbox;
127 }
128 
129 /**
130  *  e1000_check_for_bit_vf - Determine if a status bit was set
131  *  @hw: pointer to the HW structure
132  *  @mask: bitmask for bits to be tested and cleared
133  *
134  *  This function is used to check for the read to clear bits within
135  *  the V2P mailbox.
136  **/
137 static s32 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
138 {
139 	u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
140 	s32 ret_val = -E1000_ERR_MBX;
141 
142 	if (v2p_mailbox & mask)
143 		ret_val = E1000_SUCCESS;
144 
145 	hw->dev_spec.vf.v2p_mailbox &= ~mask;
146 
147 	return ret_val;
148 }
149 
150 /**
151  *  e1000_check_for_msg_vf - checks to see if the PF has sent mail
152  *  @hw: pointer to the HW structure
153  *
154  *  returns SUCCESS if the PF has set the Status bit or else ERR_MBX
155  **/
156 static s32 e1000_check_for_msg_vf(struct e1000_hw *hw)
157 {
158 	s32 ret_val = -E1000_ERR_MBX;
159 
160 	if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
161 		ret_val = E1000_SUCCESS;
162 		hw->mbx.stats.reqs++;
163 	}
164 
165 	return ret_val;
166 }
167 
168 /**
169  *  e1000_check_for_ack_vf - checks to see if the PF has ACK'd
170  *  @hw: pointer to the HW structure
171  *
172  *  returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
173  **/
174 static s32 e1000_check_for_ack_vf(struct e1000_hw *hw)
175 {
176 	s32 ret_val = -E1000_ERR_MBX;
177 
178 	if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
179 		ret_val = E1000_SUCCESS;
180 		hw->mbx.stats.acks++;
181 	}
182 
183 	return ret_val;
184 }
185 
186 /**
187  *  e1000_check_for_rst_vf - checks to see if the PF has reset
188  *  @hw: pointer to the HW structure
189  *
190  *  returns true if the PF has set the reset done bit or else false
191  **/
192 static s32 e1000_check_for_rst_vf(struct e1000_hw *hw)
193 {
194 	s32 ret_val = -E1000_ERR_MBX;
195 
196 	if (!e1000_check_for_bit_vf(hw, (E1000_V2PMAILBOX_RSTD |
197 					 E1000_V2PMAILBOX_RSTI))) {
198 		ret_val = E1000_SUCCESS;
199 		hw->mbx.stats.rsts++;
200 	}
201 
202 	return ret_val;
203 }
204 
205 /**
206  *  e1000_obtain_mbx_lock_vf - obtain mailbox lock
207  *  @hw: pointer to the HW structure
208  *
209  *  return SUCCESS if we obtained the mailbox lock
210  **/
211 static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
212 {
213 	s32 ret_val = -E1000_ERR_MBX;
214 	int count = 10;
215 
216 	do {
217 		/* Take ownership of the buffer */
218 		ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
219 
220 		/* reserve mailbox for VF use */
221 		if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU) {
222 			ret_val = 0;
223 			break;
224 		}
225 		udelay(1000);
226 	} while (count-- > 0);
227 
228 	return ret_val;
229 }
230 
231 /**
232  *  e1000_write_mbx_vf - Write a message to the mailbox
233  *  @hw: pointer to the HW structure
234  *  @msg: The message buffer
235  *  @size: Length of buffer
236  *
237  *  returns SUCCESS if it successfully copied message into the buffer
238  **/
239 static s32 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
240 {
241 	s32 err;
242 	u16 i;
243 
244 	lockdep_assert_held(&hw->mbx_lock);
245 
246 	/* lock the mailbox to prevent pf/vf race condition */
247 	err = e1000_obtain_mbx_lock_vf(hw);
248 	if (err)
249 		goto out_no_write;
250 
251 	/* flush any ack or msg as we are going to overwrite mailbox */
252 	e1000_check_for_ack_vf(hw);
253 	e1000_check_for_msg_vf(hw);
254 
255 	/* copy the caller specified message to the mailbox memory buffer */
256 	for (i = 0; i < size; i++)
257 		array_ew32(VMBMEM(0), i, msg[i]);
258 
259 	/* update stats */
260 	hw->mbx.stats.msgs_tx++;
261 
262 	/* Drop VFU and interrupt the PF to tell it a message has been sent */
263 	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
264 
265 out_no_write:
266 	return err;
267 }
268 
269 /**
270  *  e1000_read_mbx_vf - Reads a message from the inbox intended for VF
271  *  @hw: pointer to the HW structure
272  *  @msg: The message buffer
273  *  @size: Length of buffer
274  *
275  *  returns SUCCESS if it successfully read message from buffer
276  **/
277 static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
278 {
279 	s32 err;
280 	u16 i;
281 
282 	lockdep_assert_held(&hw->mbx_lock);
283 
284 	/* lock the mailbox to prevent pf/vf race condition */
285 	err = e1000_obtain_mbx_lock_vf(hw);
286 	if (err)
287 		goto out_no_read;
288 
289 	/* copy the message from the mailbox memory buffer */
290 	for (i = 0; i < size; i++)
291 		msg[i] = array_er32(VMBMEM(0), i);
292 
293 	/* Acknowledge receipt and release mailbox, then we're done */
294 	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
295 
296 	/* update stats */
297 	hw->mbx.stats.msgs_rx++;
298 
299 out_no_read:
300 	return err;
301 }
302 
303 /**
304  *  e1000_init_mbx_params_vf - set initial values for VF mailbox
305  *  @hw: pointer to the HW structure
306  *
307  *  Initializes the hw->mbx struct to correct values for VF mailbox
308  */
309 s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
310 {
311 	struct e1000_mbx_info *mbx = &hw->mbx;
312 
313 	/* start mailbox as timed out and let the reset_hw call set the timeout
314 	 * value to being communications
315 	 */
316 	mbx->timeout = 0;
317 	mbx->usec_delay = E1000_VF_MBX_INIT_DELAY;
318 
319 	mbx->size = E1000_VFMAILBOX_SIZE;
320 
321 	mbx->ops.read = e1000_read_mbx_vf;
322 	mbx->ops.write = e1000_write_mbx_vf;
323 	mbx->ops.read_posted = e1000_read_posted_mbx;
324 	mbx->ops.write_posted = e1000_write_posted_mbx;
325 	mbx->ops.check_for_msg = e1000_check_for_msg_vf;
326 	mbx->ops.check_for_ack = e1000_check_for_ack_vf;
327 	mbx->ops.check_for_rst = e1000_check_for_rst_vf;
328 
329 	mbx->stats.msgs_tx = 0;
330 	mbx->stats.msgs_rx = 0;
331 	mbx->stats.reqs = 0;
332 	mbx->stats.acks = 0;
333 	mbx->stats.rsts = 0;
334 
335 	return E1000_SUCCESS;
336 }
337