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, (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}