1// SPDX-License-Identifier: GPL-2.0
2/* Copyright(c) 2009 - 2018 Intel Corporation. */
3
4#include <linux/bitfield.h>
5#include "mbx.h"
6
7/**
8 * e1000_poll_for_msg - Wait for message notification
9 * @hw: pointer to the HW structure
10 *
11 * returns SUCCESS if it successfully received a message notification
12 **/
13static s32 e1000_poll_for_msg(struct e1000_hw *hw)
14{
15 struct e1000_mbx_info *mbx = &hw->mbx;
16 int countdown = mbx->timeout;
17
18 if (!mbx->ops.check_for_msg)
19 goto out;
20
21 while (countdown && mbx->ops.check_for_msg(hw)) {
22 countdown--;
23 udelay(mbx->usec_delay);
24 }
25
26 /* if we failed, all future posted messages fail until reset */
27 if (!countdown)
28 mbx->timeout = 0;
29out:
30 return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
31}
32
33/**
34 * e1000_poll_for_ack - Wait for message acknowledgment
35 * @hw: pointer to the HW structure
36 *
37 * returns SUCCESS if it successfully received a message acknowledgment
38 **/
39static s32 e1000_poll_for_ack(struct e1000_hw *hw)
40{
41 struct e1000_mbx_info *mbx = &hw->mbx;
42 int countdown = mbx->timeout;
43
44 if (!mbx->ops.check_for_ack)
45 goto out;
46
47 while (countdown && mbx->ops.check_for_ack(hw)) {
48 countdown--;
49 udelay(mbx->usec_delay);
50 }
51
52 /* if we failed, all future posted messages fail until reset */
53 if (!countdown)
54 mbx->timeout = 0;
55out:
56 return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
57}
58
59/**
60 * e1000_read_posted_mbx - Wait for message notification and receive message
61 * @hw: pointer to the HW structure
62 * @msg: The message buffer
63 * @size: Length of buffer
64 *
65 * returns SUCCESS if it successfully received a message notification and
66 * copied it into the receive buffer.
67 **/
68static s32 e1000_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
69{
70 struct e1000_mbx_info *mbx = &hw->mbx;
71 s32 ret_val = -E1000_ERR_MBX;
72
73 if (!mbx->ops.read)
74 goto out;
75
76 ret_val = e1000_poll_for_msg(hw);
77
78 /* if ack received read message, otherwise we timed out */
79 if (!ret_val)
80 ret_val = mbx->ops.read(hw, msg, size);
81out:
82 return ret_val;
83}
84
85/**
86 * e1000_write_posted_mbx - Write a message to the mailbox, wait for ack
87 * @hw: pointer to the HW structure
88 * @msg: The message buffer
89 * @size: Length of buffer
90 *
91 * returns SUCCESS if it successfully copied message into the buffer and
92 * received an ack to that message within delay * timeout period
93 **/
94static s32 e1000_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
95{
96 struct e1000_mbx_info *mbx = &hw->mbx;
97 s32 ret_val = -E1000_ERR_MBX;
98
99 /* exit if we either can't write or there isn't a defined timeout */
100 if (!mbx->ops.write || !mbx->timeout)
101 goto out;
102
103 /* send msg*/
104 ret_val = mbx->ops.write(hw, msg, size);
105
106 /* if msg sent wait until we receive an ack */
107 if (!ret_val)
108 ret_val = e1000_poll_for_ack(hw);
109out:
110 return ret_val;
111}
112
113/**
114 * e1000_read_v2p_mailbox - read v2p mailbox
115 * @hw: pointer to the HW structure
116 *
117 * This function is used to read the v2p mailbox without losing the read to
118 * clear status bits.
119 **/
120static u32 e1000_read_v2p_mailbox(struct e1000_hw *hw)
121{
122 u32 v2p_mailbox = er32(V2PMAILBOX(0));
123
124 v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
125 hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
126
127 return v2p_mailbox;
128}
129
130/**
131 * e1000_check_for_bit_vf - Determine if a status bit was set
132 * @hw: pointer to the HW structure
133 * @mask: bitmask for bits to be tested and cleared
134 *
135 * This function is used to check for the read to clear bits within
136 * the V2P mailbox.
137 **/
138static s32 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
139{
140 u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
141 s32 ret_val = -E1000_ERR_MBX;
142
143 if (v2p_mailbox & mask)
144 ret_val = E1000_SUCCESS;
145
146 hw->dev_spec.vf.v2p_mailbox &= ~mask;
147
148 return ret_val;
149}
150
151/**
152 * e1000_check_for_msg_vf - checks to see if the PF has sent mail
153 * @hw: pointer to the HW structure
154 *
155 * returns SUCCESS if the PF has set the Status bit or else ERR_MBX
156 **/
157static s32 e1000_check_for_msg_vf(struct e1000_hw *hw)
158{
159 s32 ret_val = -E1000_ERR_MBX;
160
161 if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
162 ret_val = E1000_SUCCESS;
163 hw->mbx.stats.reqs++;
164 }
165
166 return ret_val;
167}
168
169/**
170 * e1000_check_for_ack_vf - checks to see if the PF has ACK'd
171 * @hw: pointer to the HW structure
172 *
173 * returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
174 **/
175static s32 e1000_check_for_ack_vf(struct e1000_hw *hw)
176{
177 s32 ret_val = -E1000_ERR_MBX;
178
179 if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
180 ret_val = E1000_SUCCESS;
181 hw->mbx.stats.acks++;
182 }
183
184 return ret_val;
185}
186
187/**
188 * e1000_check_for_rst_vf - checks to see if the PF has reset
189 * @hw: pointer to the HW structure
190 *
191 * returns true if the PF has set the reset done bit or else false
192 **/
193static s32 e1000_check_for_rst_vf(struct e1000_hw *hw)
194{
195 s32 ret_val = -E1000_ERR_MBX;
196
197 if (!e1000_check_for_bit_vf(hw, mask: (E1000_V2PMAILBOX_RSTD |
198 E1000_V2PMAILBOX_RSTI))) {
199 ret_val = E1000_SUCCESS;
200 hw->mbx.stats.rsts++;
201 }
202
203 return ret_val;
204}
205
206/**
207 * e1000_obtain_mbx_lock_vf - obtain mailbox lock
208 * @hw: pointer to the HW structure
209 *
210 * return SUCCESS if we obtained the mailbox lock
211 **/
212static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
213{
214 s32 ret_val = -E1000_ERR_MBX;
215 int count = 10;
216
217 do {
218 /* Take ownership of the buffer */
219 ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
220
221 /* reserve mailbox for VF use */
222 if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU) {
223 ret_val = 0;
224 break;
225 }
226 udelay(1000);
227 } while (count-- > 0);
228
229 return ret_val;
230}
231
232/**
233 * e1000_write_mbx_vf - Write a message to the mailbox
234 * @hw: pointer to the HW structure
235 * @msg: The message buffer
236 * @size: Length of buffer
237 *
238 * returns SUCCESS if it successfully copied message into the buffer
239 **/
240static s32 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
241{
242 s32 err;
243 u16 i;
244
245 lockdep_assert_held(&hw->mbx_lock);
246
247 /* lock the mailbox to prevent pf/vf race condition */
248 err = e1000_obtain_mbx_lock_vf(hw);
249 if (err)
250 goto out_no_write;
251
252 /* flush any ack or msg as we are going to overwrite mailbox */
253 e1000_check_for_ack_vf(hw);
254 e1000_check_for_msg_vf(hw);
255
256 /* copy the caller specified message to the mailbox memory buffer */
257 for (i = 0; i < size; i++)
258 array_ew32(VMBMEM(0), i, msg[i]);
259
260 /* update stats */
261 hw->mbx.stats.msgs_tx++;
262
263 /* Drop VFU and interrupt the PF to tell it a message has been sent */
264 ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
265
266out_no_write:
267 return err;
268}
269
270/**
271 * e1000_read_mbx_vf - Reads a message from the inbox intended for VF
272 * @hw: pointer to the HW structure
273 * @msg: The message buffer
274 * @size: Length of buffer
275 *
276 * returns SUCCESS if it successfully read message from buffer
277 **/
278static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
279{
280 s32 err;
281 u16 i;
282
283 lockdep_assert_held(&hw->mbx_lock);
284
285 /* lock the mailbox to prevent pf/vf race condition */
286 err = e1000_obtain_mbx_lock_vf(hw);
287 if (err)
288 goto out_no_read;
289
290 /* copy the message from the mailbox memory buffer */
291 for (i = 0; i < size; i++)
292 msg[i] = array_er32(VMBMEM(0), i);
293
294 /* Acknowledge receipt and release mailbox, then we're done */
295 ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
296
297 /* update stats */
298 hw->mbx.stats.msgs_rx++;
299
300out_no_read:
301 return err;
302}
303
304/**
305 * e1000_init_mbx_params_vf - set initial values for VF mailbox
306 * @hw: pointer to the HW structure
307 *
308 * Initializes the hw->mbx struct to correct values for VF mailbox
309 */
310s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
311{
312 struct e1000_mbx_info *mbx = &hw->mbx;
313
314 /* start mailbox as timed out and let the reset_hw call set the timeout
315 * value to being communications
316 */
317 mbx->timeout = 0;
318 mbx->usec_delay = E1000_VF_MBX_INIT_DELAY;
319
320 mbx->size = E1000_VFMAILBOX_SIZE;
321
322 mbx->ops.read = e1000_read_mbx_vf;
323 mbx->ops.write = e1000_write_mbx_vf;
324 mbx->ops.read_posted = e1000_read_posted_mbx;
325 mbx->ops.write_posted = e1000_write_posted_mbx;
326 mbx->ops.check_for_msg = e1000_check_for_msg_vf;
327 mbx->ops.check_for_ack = e1000_check_for_ack_vf;
328 mbx->ops.check_for_rst = e1000_check_for_rst_vf;
329
330 mbx->stats.msgs_tx = 0;
331 mbx->stats.msgs_rx = 0;
332 mbx->stats.reqs = 0;
333 mbx->stats.acks = 0;
334 mbx->stats.rsts = 0;
335
336 return E1000_SUCCESS;
337}
338

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