1/*******************************************************************************
2
3  Intel(R) 82576 Virtual Function Linux driver
4  Copyright(c) 2009 - 2012 Intel Corporation.
5
6  This program is free software; you can redistribute it and/or modify it
7  under the terms and conditions of the GNU General Public License,
8  version 2, as published by the Free Software Foundation.
9
10  This program is distributed in the hope it will be useful, but WITHOUT
11  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  more details.
14
15  You should have received a copy of the GNU General Public License along with
16  this program; if not, write to the Free Software Foundation, Inc.,
17  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18
19  The full GNU General Public License is included in this distribution in
20  the file called "COPYING".
21
22  Contact Information:
23  e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
24  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
25
26*******************************************************************************/
27
28#include "mbx.h"
29
30/**
31 *  e1000_poll_for_msg - Wait for message notification
32 *  @hw: pointer to the HW structure
33 *
34 *  returns SUCCESS if it successfully received a message notification
35 **/
36static s32 e1000_poll_for_msg(struct e1000_hw *hw)
37{
38	struct e1000_mbx_info *mbx = &hw->mbx;
39	int countdown = mbx->timeout;
40
41	if (!mbx->ops.check_for_msg)
42		goto out;
43
44	while (countdown && mbx->ops.check_for_msg(hw)) {
45		countdown--;
46		udelay(mbx->usec_delay);
47	}
48
49	/* if we failed, all future posted messages fail until reset */
50	if (!countdown)
51		mbx->timeout = 0;
52out:
53	return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
54}
55
56/**
57 *  e1000_poll_for_ack - Wait for message acknowledgement
58 *  @hw: pointer to the HW structure
59 *
60 *  returns SUCCESS if it successfully received a message acknowledgement
61 **/
62static s32 e1000_poll_for_ack(struct e1000_hw *hw)
63{
64	struct e1000_mbx_info *mbx = &hw->mbx;
65	int countdown = mbx->timeout;
66
67	if (!mbx->ops.check_for_ack)
68		goto out;
69
70	while (countdown && mbx->ops.check_for_ack(hw)) {
71		countdown--;
72		udelay(mbx->usec_delay);
73	}
74
75	/* if we failed, all future posted messages fail until reset */
76	if (!countdown)
77		mbx->timeout = 0;
78out:
79	return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
80}
81
82/**
83 *  e1000_read_posted_mbx - Wait for message notification and receive message
84 *  @hw: pointer to the HW structure
85 *  @msg: The message buffer
86 *  @size: Length of buffer
87 *
88 *  returns SUCCESS if it successfully received a message notification and
89 *  copied it into the receive buffer.
90 **/
91static s32 e1000_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
92{
93	struct e1000_mbx_info *mbx = &hw->mbx;
94	s32 ret_val = -E1000_ERR_MBX;
95
96	if (!mbx->ops.read)
97		goto out;
98
99	ret_val = e1000_poll_for_msg(hw);
100
101	/* if ack received read message, otherwise we timed out */
102	if (!ret_val)
103		ret_val = mbx->ops.read(hw, msg, size);
104out:
105	return ret_val;
106}
107
108/**
109 *  e1000_write_posted_mbx - Write a message to the mailbox, wait for ack
110 *  @hw: pointer to the HW structure
111 *  @msg: The message buffer
112 *  @size: Length of buffer
113 *
114 *  returns SUCCESS if it successfully copied message into the buffer and
115 *  received an ack to that message within delay * timeout period
116 **/
117static s32 e1000_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
118{
119	struct e1000_mbx_info *mbx = &hw->mbx;
120	s32 ret_val = -E1000_ERR_MBX;
121
122	/* exit if we either can't write or there isn't a defined timeout */
123	if (!mbx->ops.write || !mbx->timeout)
124		goto out;
125
126	/* send msg*/
127	ret_val = mbx->ops.write(hw, msg, size);
128
129	/* if msg sent wait until we receive an ack */
130	if (!ret_val)
131		ret_val = e1000_poll_for_ack(hw);
132out:
133	return ret_val;
134}
135
136/**
137 *  e1000_read_v2p_mailbox - read v2p mailbox
138 *  @hw: pointer to the HW structure
139 *
140 *  This function is used to read the v2p mailbox without losing the read to
141 *  clear status bits.
142 **/
143static u32 e1000_read_v2p_mailbox(struct e1000_hw *hw)
144{
145	u32 v2p_mailbox = er32(V2PMAILBOX(0));
146
147	v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
148	hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
149
150	return v2p_mailbox;
151}
152
153/**
154 *  e1000_check_for_bit_vf - Determine if a status bit was set
155 *  @hw: pointer to the HW structure
156 *  @mask: bitmask for bits to be tested and cleared
157 *
158 *  This function is used to check for the read to clear bits within
159 *  the V2P mailbox.
160 **/
161static s32 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
162{
163	u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
164	s32 ret_val = -E1000_ERR_MBX;
165
166	if (v2p_mailbox & mask)
167		ret_val = E1000_SUCCESS;
168
169	hw->dev_spec.vf.v2p_mailbox &= ~mask;
170
171	return ret_val;
172}
173
174/**
175 *  e1000_check_for_msg_vf - checks to see if the PF has sent mail
176 *  @hw: pointer to the HW structure
177 *
178 *  returns SUCCESS if the PF has set the Status bit or else ERR_MBX
179 **/
180static s32 e1000_check_for_msg_vf(struct e1000_hw *hw)
181{
182	s32 ret_val = -E1000_ERR_MBX;
183
184	if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
185		ret_val = E1000_SUCCESS;
186		hw->mbx.stats.reqs++;
187	}
188
189	return ret_val;
190}
191
192/**
193 *  e1000_check_for_ack_vf - checks to see if the PF has ACK'd
194 *  @hw: pointer to the HW structure
195 *
196 *  returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
197 **/
198static s32 e1000_check_for_ack_vf(struct e1000_hw *hw)
199{
200	s32 ret_val = -E1000_ERR_MBX;
201
202	if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
203		ret_val = E1000_SUCCESS;
204		hw->mbx.stats.acks++;
205	}
206
207	return ret_val;
208}
209
210/**
211 *  e1000_check_for_rst_vf - checks to see if the PF has reset
212 *  @hw: pointer to the HW structure
213 *
214 *  returns true if the PF has set the reset done bit or else false
215 **/
216static s32 e1000_check_for_rst_vf(struct e1000_hw *hw)
217{
218	s32 ret_val = -E1000_ERR_MBX;
219
220	if (!e1000_check_for_bit_vf(hw, (E1000_V2PMAILBOX_RSTD |
221	                                 E1000_V2PMAILBOX_RSTI))) {
222		ret_val = E1000_SUCCESS;
223		hw->mbx.stats.rsts++;
224	}
225
226	return ret_val;
227}
228
229/**
230 *  e1000_obtain_mbx_lock_vf - obtain mailbox lock
231 *  @hw: pointer to the HW structure
232 *
233 *  return SUCCESS if we obtained the mailbox lock
234 **/
235static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
236{
237	s32 ret_val = -E1000_ERR_MBX;
238
239	/* Take ownership of the buffer */
240	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
241
242	/* reserve mailbox for vf use */
243	if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU)
244		ret_val = E1000_SUCCESS;
245
246	return ret_val;
247}
248
249/**
250 *  e1000_write_mbx_vf - Write a message to the mailbox
251 *  @hw: pointer to the HW structure
252 *  @msg: The message buffer
253 *  @size: Length of buffer
254 *
255 *  returns SUCCESS if it successfully copied message into the buffer
256 **/
257static s32 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
258{
259	s32 err;
260	u16 i;
261
262	/* lock the mailbox to prevent pf/vf race condition */
263	err = e1000_obtain_mbx_lock_vf(hw);
264	if (err)
265		goto out_no_write;
266
267	/* flush any ack or msg as we are going to overwrite mailbox */
268	e1000_check_for_ack_vf(hw);
269	e1000_check_for_msg_vf(hw);
270
271	/* copy the caller specified message to the mailbox memory buffer */
272	for (i = 0; i < size; i++)
273		array_ew32(VMBMEM(0), i, msg[i]);
274
275	/* update stats */
276	hw->mbx.stats.msgs_tx++;
277
278	/* Drop VFU and interrupt the PF to tell it a message has been sent */
279	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
280
281out_no_write:
282	return err;
283}
284
285/**
286 *  e1000_read_mbx_vf - Reads a message from the inbox intended for vf
287 *  @hw: pointer to the HW structure
288 *  @msg: The message buffer
289 *  @size: Length of buffer
290 *
291 *  returns SUCCESS if it successfully read message from buffer
292 **/
293static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
294{
295	s32 err;
296	u16 i;
297
298	/* lock the mailbox to prevent pf/vf race condition */
299	err = e1000_obtain_mbx_lock_vf(hw);
300	if (err)
301		goto out_no_read;
302
303	/* copy the message from the mailbox memory buffer */
304	for (i = 0; i < size; i++)
305		msg[i] = array_er32(VMBMEM(0), i);
306
307	/* Acknowledge receipt and release mailbox, then we're done */
308	ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
309
310	/* update stats */
311	hw->mbx.stats.msgs_rx++;
312
313out_no_read:
314	return err;
315}
316
317/**
318 *  e1000_init_mbx_params_vf - set initial values for vf mailbox
319 *  @hw: pointer to the HW structure
320 *
321 *  Initializes the hw->mbx struct to correct values for vf mailbox
322 */
323s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
324{
325	struct e1000_mbx_info *mbx = &hw->mbx;
326
327	/* start mailbox as timed out and let the reset_hw call set the timeout
328	 * value to being communications */
329	mbx->timeout = 0;
330	mbx->usec_delay = E1000_VF_MBX_INIT_DELAY;
331
332	mbx->size = E1000_VFMAILBOX_SIZE;
333
334	mbx->ops.read = e1000_read_mbx_vf;
335	mbx->ops.write = e1000_write_mbx_vf;
336	mbx->ops.read_posted = e1000_read_posted_mbx;
337	mbx->ops.write_posted = e1000_write_posted_mbx;
338	mbx->ops.check_for_msg = e1000_check_for_msg_vf;
339	mbx->ops.check_for_ack = e1000_check_for_ack_vf;
340	mbx->ops.check_for_rst = e1000_check_for_rst_vf;
341
342	mbx->stats.msgs_tx = 0;
343	mbx->stats.msgs_rx = 0;
344	mbx->stats.reqs = 0;
345	mbx->stats.acks = 0;
346	mbx->stats.rsts = 0;
347
348	return E1000_SUCCESS;
349}
350
351