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 **/
12static 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;
28out:
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 **/
38static 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;
54out:
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 **/
67static 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);
80out:
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 **/
93static 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);
108out:
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 **/
119static 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 **/
137static 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 **/
156static 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 **/
174static 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 **/
192static 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, mask: (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 **/
211static 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 **/
239static 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
265out_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 **/
277static 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
299out_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 */
309s32 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

source code of linux/drivers/net/ethernet/intel/igbvf/mbx.c