1 /*
2  * ISHTP bus layer messages handling
3  *
4  * Copyright (c) 2003-2016, 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  */
16 
17 #include <linux/export.h>
18 #include <linux/slab.h>
19 #include <linux/sched.h>
20 #include <linux/wait.h>
21 #include <linux/spinlock.h>
22 #include "ishtp-dev.h"
23 #include "hbm.h"
24 #include "client.h"
25 
26 /**
27  * ishtp_hbm_fw_cl_allocate() - Allocate FW clients
28  * @dev: ISHTP device instance
29  *
30  * Allocates storage for fw clients
31  */
32 static void ishtp_hbm_fw_cl_allocate(struct ishtp_device *dev)
33 {
34 	struct ishtp_fw_client *clients;
35 	int b;
36 
37 	/* count how many ISH clients we have */
38 	for_each_set_bit(b, dev->fw_clients_map, ISHTP_CLIENTS_MAX)
39 		dev->fw_clients_num++;
40 
41 	if (dev->fw_clients_num <= 0)
42 		return;
43 
44 	/* allocate storage for fw clients representation */
45 	clients = kcalloc(dev->fw_clients_num, sizeof(struct ishtp_fw_client),
46 			  GFP_KERNEL);
47 	if (!clients) {
48 		dev->dev_state = ISHTP_DEV_RESETTING;
49 		ish_hw_reset(dev);
50 		return;
51 	}
52 	dev->fw_clients = clients;
53 }
54 
55 /**
56  * ishtp_hbm_cl_hdr() - construct client hbm header
57  * @cl: client
58  * @hbm_cmd: host bus message command
59  * @buf: buffer for cl header
60  * @len: buffer length
61  *
62  * Initialize HBM buffer
63  */
64 static inline void ishtp_hbm_cl_hdr(struct ishtp_cl *cl, uint8_t hbm_cmd,
65 	void *buf, size_t len)
66 {
67 	struct ishtp_hbm_cl_cmd *cmd = buf;
68 
69 	memset(cmd, 0, len);
70 
71 	cmd->hbm_cmd = hbm_cmd;
72 	cmd->host_addr = cl->host_client_id;
73 	cmd->fw_addr = cl->fw_client_id;
74 }
75 
76 /**
77  * ishtp_hbm_cl_addr_equal() - Compare client address
78  * @cl: client
79  * @buf: Client command buffer
80  *
81  * Compare client address with the address in command buffer
82  *
83  * Return: True if they have the same address
84  */
85 static inline bool ishtp_hbm_cl_addr_equal(struct ishtp_cl *cl, void *buf)
86 {
87 	struct ishtp_hbm_cl_cmd *cmd = buf;
88 
89 	return cl->host_client_id == cmd->host_addr &&
90 		cl->fw_client_id == cmd->fw_addr;
91 }
92 
93 /**
94  * ishtp_hbm_start_wait() - Wait for HBM start message
95  * @dev: ISHTP device instance
96  *
97  * Wait for HBM start message from firmware
98  *
99  * Return: 0 if HBM start is/was received else timeout error
100  */
101 int ishtp_hbm_start_wait(struct ishtp_device *dev)
102 {
103 	int ret;
104 
105 	if (dev->hbm_state > ISHTP_HBM_START)
106 		return 0;
107 
108 	dev_dbg(dev->devc, "Going to wait for ishtp start. hbm_state=%08X\n",
109 		dev->hbm_state);
110 	ret = wait_event_interruptible_timeout(dev->wait_hbm_recvd_msg,
111 					dev->hbm_state >= ISHTP_HBM_STARTED,
112 					(ISHTP_INTEROP_TIMEOUT * HZ));
113 
114 	dev_dbg(dev->devc,
115 		"Woke up from waiting for ishtp start. hbm_state=%08X\n",
116 		dev->hbm_state);
117 
118 	if (ret <= 0 && (dev->hbm_state <= ISHTP_HBM_START)) {
119 		dev->hbm_state = ISHTP_HBM_IDLE;
120 		dev_err(dev->devc,
121 		"waiting for ishtp start failed. ret=%d hbm_state=%08X\n",
122 			ret, dev->hbm_state);
123 		return -ETIMEDOUT;
124 	}
125 	return 0;
126 }
127 
128 /**
129  * ishtp_hbm_start_req() - Send HBM start message
130  * @dev: ISHTP device instance
131  *
132  * Send HBM start message to firmware
133  *
134  * Return: 0 if success else error code
135  */
136 int ishtp_hbm_start_req(struct ishtp_device *dev)
137 {
138 	struct ishtp_msg_hdr hdr;
139 	unsigned char data[128];
140 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
141 	struct hbm_host_version_request *start_req;
142 	const size_t len = sizeof(struct hbm_host_version_request);
143 
144 	ishtp_hbm_hdr(ishtp_hdr, len);
145 
146 	/* host start message */
147 	start_req = (struct hbm_host_version_request *)data;
148 	memset(start_req, 0, len);
149 	start_req->hbm_cmd = HOST_START_REQ_CMD;
150 	start_req->host_version.major_version = HBM_MAJOR_VERSION;
151 	start_req->host_version.minor_version = HBM_MINOR_VERSION;
152 
153 	/*
154 	 * (!) Response to HBM start may be so quick that this thread would get
155 	 * preempted BEFORE managing to set hbm_state = ISHTP_HBM_START.
156 	 * So set it at first, change back to ISHTP_HBM_IDLE upon failure
157 	 */
158 	dev->hbm_state = ISHTP_HBM_START;
159 	if (ishtp_write_message(dev, ishtp_hdr, data)) {
160 		dev_err(dev->devc, "version message send failed\n");
161 		dev->dev_state = ISHTP_DEV_RESETTING;
162 		dev->hbm_state = ISHTP_HBM_IDLE;
163 		ish_hw_reset(dev);
164 		return -ENODEV;
165 	}
166 
167 	return 0;
168 }
169 
170 /**
171  * ishtp_hbm_enum_clients_req() - Send client enum req
172  * @dev: ISHTP device instance
173  *
174  * Send enumeration client request message
175  *
176  * Return: 0 if success else error code
177  */
178 void ishtp_hbm_enum_clients_req(struct ishtp_device *dev)
179 {
180 	struct ishtp_msg_hdr hdr;
181 	unsigned char data[128];
182 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
183 	struct hbm_host_enum_request *enum_req;
184 	const size_t len = sizeof(struct hbm_host_enum_request);
185 
186 	/* enumerate clients */
187 	ishtp_hbm_hdr(ishtp_hdr, len);
188 
189 	enum_req = (struct hbm_host_enum_request *)data;
190 	memset(enum_req, 0, len);
191 	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
192 
193 	if (ishtp_write_message(dev, ishtp_hdr, data)) {
194 		dev->dev_state = ISHTP_DEV_RESETTING;
195 		dev_err(dev->devc, "enumeration request send failed\n");
196 		ish_hw_reset(dev);
197 	}
198 	dev->hbm_state = ISHTP_HBM_ENUM_CLIENTS;
199 }
200 
201 /**
202  * ishtp_hbm_prop_req() - Request property
203  * @dev: ISHTP device instance
204  *
205  * Request property for a single client
206  *
207  * Return: 0 if success else error code
208  */
209 static int ishtp_hbm_prop_req(struct ishtp_device *dev)
210 {
211 
212 	struct ishtp_msg_hdr hdr;
213 	unsigned char data[128];
214 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
215 	struct hbm_props_request *prop_req;
216 	const size_t len = sizeof(struct hbm_props_request);
217 	unsigned long next_client_index;
218 	uint8_t client_num;
219 
220 	client_num = dev->fw_client_presentation_num;
221 
222 	next_client_index = find_next_bit(dev->fw_clients_map,
223 		ISHTP_CLIENTS_MAX, dev->fw_client_index);
224 
225 	/* We got all client properties */
226 	if (next_client_index == ISHTP_CLIENTS_MAX) {
227 		dev->hbm_state = ISHTP_HBM_WORKING;
228 		dev->dev_state = ISHTP_DEV_ENABLED;
229 
230 		for (dev->fw_client_presentation_num = 1;
231 			dev->fw_client_presentation_num < client_num + 1;
232 				++dev->fw_client_presentation_num)
233 			/* Add new client device */
234 			ishtp_bus_new_client(dev);
235 		return 0;
236 	}
237 
238 	dev->fw_clients[client_num].client_id = next_client_index;
239 
240 	ishtp_hbm_hdr(ishtp_hdr, len);
241 	prop_req = (struct hbm_props_request *)data;
242 
243 	memset(prop_req, 0, sizeof(struct hbm_props_request));
244 
245 	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
246 	prop_req->address = next_client_index;
247 
248 	if (ishtp_write_message(dev, ishtp_hdr, data)) {
249 		dev->dev_state = ISHTP_DEV_RESETTING;
250 		dev_err(dev->devc, "properties request send failed\n");
251 		ish_hw_reset(dev);
252 		return -EIO;
253 	}
254 
255 	dev->fw_client_index = next_client_index;
256 
257 	return 0;
258 }
259 
260 /**
261  * ishtp_hbm_stop_req() - Send HBM stop
262  * @dev: ISHTP device instance
263  *
264  * Send stop request message
265  */
266 static void ishtp_hbm_stop_req(struct ishtp_device *dev)
267 {
268 	struct ishtp_msg_hdr hdr;
269 	unsigned char data[128];
270 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
271 	struct hbm_host_stop_request *req;
272 	const size_t len = sizeof(struct hbm_host_stop_request);
273 
274 	ishtp_hbm_hdr(ishtp_hdr, len);
275 	req = (struct hbm_host_stop_request *)data;
276 
277 	memset(req, 0, sizeof(struct hbm_host_stop_request));
278 	req->hbm_cmd = HOST_STOP_REQ_CMD;
279 	req->reason = DRIVER_STOP_REQUEST;
280 
281 	ishtp_write_message(dev, ishtp_hdr, data);
282 }
283 
284 /**
285  * ishtp_hbm_cl_flow_control_req() - Send flow control request
286  * @dev: ISHTP device instance
287  * @cl: ISHTP client instance
288  *
289  * Send flow control request
290  *
291  * Return: 0 if success else error code
292  */
293 int ishtp_hbm_cl_flow_control_req(struct ishtp_device *dev,
294 				  struct ishtp_cl *cl)
295 {
296 	struct ishtp_msg_hdr hdr;
297 	unsigned char data[128];
298 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
299 	const size_t len = sizeof(struct hbm_flow_control);
300 	int	rv;
301 	unsigned int	num_frags;
302 	unsigned long	flags;
303 
304 	spin_lock_irqsave(&cl->fc_spinlock, flags);
305 	ishtp_hbm_hdr(ishtp_hdr, len);
306 	ishtp_hbm_cl_hdr(cl, ISHTP_FLOW_CONTROL_CMD, data, len);
307 
308 	/*
309 	 * Sync possible race when RB recycle and packet receive paths
310 	 * both try to send an out FC
311 	 */
312 	if (cl->out_flow_ctrl_creds) {
313 		spin_unlock_irqrestore(&cl->fc_spinlock, flags);
314 		return	0;
315 	}
316 
317 	num_frags = cl->recv_msg_num_frags;
318 	cl->recv_msg_num_frags = 0;
319 
320 	rv = ishtp_write_message(dev, ishtp_hdr, data);
321 	if (!rv) {
322 		++cl->out_flow_ctrl_creds;
323 		++cl->out_flow_ctrl_cnt;
324 		cl->ts_out_fc = ktime_get();
325 		if (cl->ts_rx) {
326 			ktime_t ts_diff = ktime_sub(cl->ts_out_fc, cl->ts_rx);
327 			if (ktime_after(ts_diff, cl->ts_max_fc_delay))
328 				cl->ts_max_fc_delay = ts_diff;
329 		}
330 	} else {
331 		++cl->err_send_fc;
332 	}
333 
334 	spin_unlock_irqrestore(&cl->fc_spinlock, flags);
335 	return	rv;
336 }
337 
338 /**
339  * ishtp_hbm_cl_disconnect_req() - Send disconnect request
340  * @dev: ISHTP device instance
341  * @cl: ISHTP client instance
342  *
343  * Send disconnect message to fw
344  *
345  * Return: 0 if success else error code
346  */
347 int ishtp_hbm_cl_disconnect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
348 {
349 	struct ishtp_msg_hdr hdr;
350 	unsigned char data[128];
351 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
352 	const size_t len = sizeof(struct hbm_client_connect_request);
353 
354 	ishtp_hbm_hdr(ishtp_hdr, len);
355 	ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_REQ_CMD, data, len);
356 
357 	return ishtp_write_message(dev, ishtp_hdr, data);
358 }
359 
360 /**
361  * ishtp_hbm_cl_disconnect_res() - Get disconnect response
362  * @dev: ISHTP device instance
363  * @rs: Response message
364  *
365  * Received disconnect response from fw
366  */
367 static void ishtp_hbm_cl_disconnect_res(struct ishtp_device *dev,
368 	struct hbm_client_connect_response *rs)
369 {
370 	struct ishtp_cl *cl = NULL;
371 	unsigned long	flags;
372 
373 	spin_lock_irqsave(&dev->cl_list_lock, flags);
374 	list_for_each_entry(cl, &dev->cl_list, link) {
375 		if (!rs->status && ishtp_hbm_cl_addr_equal(cl, rs)) {
376 			cl->state = ISHTP_CL_DISCONNECTED;
377 			wake_up_interruptible(&cl->wait_ctrl_res);
378 			break;
379 		}
380 	}
381 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
382 }
383 
384 /**
385  * ishtp_hbm_cl_connect_req() - Send connect request
386  * @dev: ISHTP device instance
387  * @cl: client device instance
388  *
389  * Send connection request to specific fw client
390  *
391  * Return: 0 if success else error code
392  */
393 int ishtp_hbm_cl_connect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
394 {
395 	struct ishtp_msg_hdr hdr;
396 	unsigned char data[128];
397 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
398 	const size_t len = sizeof(struct hbm_client_connect_request);
399 
400 	ishtp_hbm_hdr(ishtp_hdr, len);
401 	ishtp_hbm_cl_hdr(cl, CLIENT_CONNECT_REQ_CMD, data, len);
402 
403 	return ishtp_write_message(dev, ishtp_hdr, data);
404 }
405 
406 /**
407  * ishtp_hbm_cl_connect_res() - Get connect response
408  * @dev: ISHTP device instance
409  * @rs: Response message
410  *
411  * Received connect response from fw
412  */
413 static void ishtp_hbm_cl_connect_res(struct ishtp_device *dev,
414 	struct hbm_client_connect_response *rs)
415 {
416 	struct ishtp_cl *cl = NULL;
417 	unsigned long	flags;
418 
419 	spin_lock_irqsave(&dev->cl_list_lock, flags);
420 	list_for_each_entry(cl, &dev->cl_list, link) {
421 		if (ishtp_hbm_cl_addr_equal(cl, rs)) {
422 			if (!rs->status) {
423 				cl->state = ISHTP_CL_CONNECTED;
424 				cl->status = 0;
425 			} else {
426 				cl->state = ISHTP_CL_DISCONNECTED;
427 				cl->status = -ENODEV;
428 			}
429 			wake_up_interruptible(&cl->wait_ctrl_res);
430 			break;
431 		}
432 	}
433 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
434 }
435 
436 /**
437  * ishtp_client_disconnect_request() - Receive disconnect request
438  * @dev: ISHTP device instance
439  * @disconnect_req: disconnect request structure
440  *
441  * Disconnect request bus message from the fw. Send diconnect response.
442  */
443 static void ishtp_hbm_fw_disconnect_req(struct ishtp_device *dev,
444 	struct hbm_client_connect_request *disconnect_req)
445 {
446 	struct ishtp_cl *cl;
447 	const size_t len = sizeof(struct hbm_client_connect_response);
448 	unsigned long	flags;
449 	struct ishtp_msg_hdr hdr;
450 	unsigned char data[4];	/* All HBM messages are 4 bytes */
451 
452 	spin_lock_irqsave(&dev->cl_list_lock, flags);
453 	list_for_each_entry(cl, &dev->cl_list, link) {
454 		if (ishtp_hbm_cl_addr_equal(cl, disconnect_req)) {
455 			cl->state = ISHTP_CL_DISCONNECTED;
456 
457 			/* send disconnect response */
458 			ishtp_hbm_hdr(&hdr, len);
459 			ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD, data,
460 				len);
461 			ishtp_write_message(dev, &hdr, data);
462 			break;
463 		}
464 	}
465 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
466 }
467 
468 /**
469  * ishtp_hbm_dma_xfer_ack(() - Receive transfer ACK
470  * @dev: ISHTP device instance
471  * @dma_xfer: HBM transfer message
472  *
473  * Receive ack for ISHTP-over-DMA client message
474  */
475 static void ishtp_hbm_dma_xfer_ack(struct ishtp_device *dev,
476 				   struct dma_xfer_hbm *dma_xfer)
477 {
478 	void	*msg;
479 	uint64_t	offs;
480 	struct ishtp_msg_hdr	*ishtp_hdr =
481 		(struct ishtp_msg_hdr *)&dev->ishtp_msg_hdr;
482 	unsigned int	msg_offs;
483 	struct ishtp_cl *cl;
484 
485 	for (msg_offs = 0; msg_offs < ishtp_hdr->length;
486 		msg_offs += sizeof(struct dma_xfer_hbm)) {
487 		offs = dma_xfer->msg_addr - dev->ishtp_host_dma_tx_buf_phys;
488 		if (offs > dev->ishtp_host_dma_tx_buf_size) {
489 			dev_err(dev->devc, "Bad DMA Tx ack message address\n");
490 			return;
491 		}
492 		if (dma_xfer->msg_length >
493 				dev->ishtp_host_dma_tx_buf_size - offs) {
494 			dev_err(dev->devc, "Bad DMA Tx ack message size\n");
495 			return;
496 		}
497 
498 		/* logical address of the acked mem */
499 		msg = (unsigned char *)dev->ishtp_host_dma_tx_buf + offs;
500 		ishtp_cl_release_dma_acked_mem(dev, msg, dma_xfer->msg_length);
501 
502 		list_for_each_entry(cl, &dev->cl_list, link) {
503 			if (cl->fw_client_id == dma_xfer->fw_client_id &&
504 			    cl->host_client_id == dma_xfer->host_client_id)
505 				/*
506 				 * in case that a single ack may be sent
507 				 * over several dma transfers, and the last msg
508 				 * addr was inside the acked memory, but not in
509 				 * its start
510 				 */
511 				if (cl->last_dma_addr >=
512 							(unsigned char *)msg &&
513 						cl->last_dma_addr <
514 						(unsigned char *)msg +
515 						dma_xfer->msg_length) {
516 					cl->last_dma_acked = 1;
517 
518 					if (!list_empty(&cl->tx_list.list) &&
519 						cl->ishtp_flow_ctrl_creds) {
520 						/*
521 						 * start sending the first msg
522 						 */
523 						ishtp_cl_send_msg(dev, cl);
524 					}
525 				}
526 		}
527 		++dma_xfer;
528 	}
529 }
530 
531 /**
532  * ishtp_hbm_dma_xfer() - Receive DMA transfer message
533  * @dev: ISHTP device instance
534  * @dma_xfer: HBM transfer message
535  *
536  * Receive ISHTP-over-DMA client message
537  */
538 static void ishtp_hbm_dma_xfer(struct ishtp_device *dev,
539 			       struct dma_xfer_hbm *dma_xfer)
540 {
541 	void	*msg;
542 	uint64_t	offs;
543 	struct ishtp_msg_hdr	hdr;
544 	struct ishtp_msg_hdr	*ishtp_hdr =
545 		(struct ishtp_msg_hdr *) &dev->ishtp_msg_hdr;
546 	struct dma_xfer_hbm	*prm = dma_xfer;
547 	unsigned int	msg_offs;
548 
549 	for (msg_offs = 0; msg_offs < ishtp_hdr->length;
550 		msg_offs += sizeof(struct dma_xfer_hbm)) {
551 
552 		offs = dma_xfer->msg_addr - dev->ishtp_host_dma_rx_buf_phys;
553 		if (offs > dev->ishtp_host_dma_rx_buf_size) {
554 			dev_err(dev->devc, "Bad DMA Rx message address\n");
555 			return;
556 		}
557 		if (dma_xfer->msg_length >
558 				dev->ishtp_host_dma_rx_buf_size - offs) {
559 			dev_err(dev->devc, "Bad DMA Rx message size\n");
560 			return;
561 		}
562 		msg = dev->ishtp_host_dma_rx_buf + offs;
563 		recv_ishtp_cl_msg_dma(dev, msg, dma_xfer);
564 		dma_xfer->hbm = DMA_XFER_ACK;	/* Prepare for response */
565 		++dma_xfer;
566 	}
567 
568 	/* Send DMA_XFER_ACK [...] */
569 	ishtp_hbm_hdr(&hdr, ishtp_hdr->length);
570 	ishtp_write_message(dev, &hdr, (unsigned char *)prm);
571 }
572 
573 /**
574  * ishtp_hbm_dispatch() - HBM dispatch function
575  * @dev: ISHTP device instance
576  * @hdr: bus message
577  *
578  * Bottom half read routine after ISR to handle the read bus message cmd
579  * processing
580  */
581 void ishtp_hbm_dispatch(struct ishtp_device *dev,
582 			struct ishtp_bus_message *hdr)
583 {
584 	struct ishtp_bus_message *ishtp_msg;
585 	struct ishtp_fw_client *fw_client;
586 	struct hbm_host_version_response *version_res;
587 	struct hbm_client_connect_response *connect_res;
588 	struct hbm_client_connect_response *disconnect_res;
589 	struct hbm_client_connect_request *disconnect_req;
590 	struct hbm_props_response *props_res;
591 	struct hbm_host_enum_response *enum_res;
592 	struct ishtp_msg_hdr ishtp_hdr;
593 	struct dma_alloc_notify	dma_alloc_notify;
594 	struct dma_xfer_hbm	*dma_xfer;
595 
596 	ishtp_msg = hdr;
597 
598 	switch (ishtp_msg->hbm_cmd) {
599 	case HOST_START_RES_CMD:
600 		version_res = (struct hbm_host_version_response *)ishtp_msg;
601 		if (!version_res->host_version_supported) {
602 			dev->version = version_res->fw_max_version;
603 
604 			dev->hbm_state = ISHTP_HBM_STOPPED;
605 			ishtp_hbm_stop_req(dev);
606 			return;
607 		}
608 
609 		dev->version.major_version = HBM_MAJOR_VERSION;
610 		dev->version.minor_version = HBM_MINOR_VERSION;
611 		if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
612 				dev->hbm_state == ISHTP_HBM_START) {
613 			dev->hbm_state = ISHTP_HBM_STARTED;
614 			ishtp_hbm_enum_clients_req(dev);
615 		} else {
616 			dev_err(dev->devc,
617 				"reset: wrong host start response\n");
618 			/* BUG: why do we arrive here? */
619 			ish_hw_reset(dev);
620 			return;
621 		}
622 
623 		wake_up_interruptible(&dev->wait_hbm_recvd_msg);
624 		break;
625 
626 	case CLIENT_CONNECT_RES_CMD:
627 		connect_res = (struct hbm_client_connect_response *)ishtp_msg;
628 		ishtp_hbm_cl_connect_res(dev, connect_res);
629 		break;
630 
631 	case CLIENT_DISCONNECT_RES_CMD:
632 		disconnect_res =
633 			(struct hbm_client_connect_response *)ishtp_msg;
634 		ishtp_hbm_cl_disconnect_res(dev, disconnect_res);
635 		break;
636 
637 	case HOST_CLIENT_PROPERTIES_RES_CMD:
638 		props_res = (struct hbm_props_response *)ishtp_msg;
639 		fw_client = &dev->fw_clients[dev->fw_client_presentation_num];
640 
641 		if (props_res->status || !dev->fw_clients) {
642 			dev_err(dev->devc,
643 			"reset: properties response hbm wrong status\n");
644 			ish_hw_reset(dev);
645 			return;
646 		}
647 
648 		if (fw_client->client_id != props_res->address) {
649 			dev_err(dev->devc,
650 				"reset: host properties response address mismatch [%02X %02X]\n",
651 				fw_client->client_id, props_res->address);
652 			ish_hw_reset(dev);
653 			return;
654 		}
655 
656 		if (dev->dev_state != ISHTP_DEV_INIT_CLIENTS ||
657 			dev->hbm_state != ISHTP_HBM_CLIENT_PROPERTIES) {
658 			dev_err(dev->devc,
659 				"reset: unexpected properties response\n");
660 			ish_hw_reset(dev);
661 			return;
662 		}
663 
664 		fw_client->props = props_res->client_properties;
665 		dev->fw_client_index++;
666 		dev->fw_client_presentation_num++;
667 
668 		/* request property for the next client */
669 		ishtp_hbm_prop_req(dev);
670 
671 		if (dev->dev_state != ISHTP_DEV_ENABLED)
672 			break;
673 
674 		if (!ishtp_use_dma_transfer())
675 			break;
676 
677 		dev_dbg(dev->devc, "Requesting to use DMA\n");
678 		ishtp_cl_alloc_dma_buf(dev);
679 		if (dev->ishtp_host_dma_rx_buf) {
680 			const size_t len = sizeof(dma_alloc_notify);
681 
682 			memset(&dma_alloc_notify, 0, sizeof(dma_alloc_notify));
683 			dma_alloc_notify.hbm = DMA_BUFFER_ALLOC_NOTIFY;
684 			dma_alloc_notify.buf_size =
685 					dev->ishtp_host_dma_rx_buf_size;
686 			dma_alloc_notify.buf_address =
687 					dev->ishtp_host_dma_rx_buf_phys;
688 			ishtp_hbm_hdr(&ishtp_hdr, len);
689 			ishtp_write_message(dev, &ishtp_hdr,
690 				(unsigned char *)&dma_alloc_notify);
691 		}
692 
693 		break;
694 
695 	case HOST_ENUM_RES_CMD:
696 		enum_res = (struct hbm_host_enum_response *) ishtp_msg;
697 		memcpy(dev->fw_clients_map, enum_res->valid_addresses, 32);
698 		if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
699 			dev->hbm_state == ISHTP_HBM_ENUM_CLIENTS) {
700 			dev->fw_client_presentation_num = 0;
701 			dev->fw_client_index = 0;
702 
703 			ishtp_hbm_fw_cl_allocate(dev);
704 			dev->hbm_state = ISHTP_HBM_CLIENT_PROPERTIES;
705 
706 			/* first property request */
707 			ishtp_hbm_prop_req(dev);
708 		} else {
709 			dev_err(dev->devc,
710 			      "reset: unexpected enumeration response hbm\n");
711 			ish_hw_reset(dev);
712 			return;
713 		}
714 		break;
715 
716 	case HOST_STOP_RES_CMD:
717 		if (dev->hbm_state != ISHTP_HBM_STOPPED)
718 			dev_err(dev->devc, "unexpected stop response\n");
719 
720 		dev->dev_state = ISHTP_DEV_DISABLED;
721 		dev_info(dev->devc, "reset: FW stop response\n");
722 		ish_hw_reset(dev);
723 		break;
724 
725 	case CLIENT_DISCONNECT_REQ_CMD:
726 		/* search for client */
727 		disconnect_req =
728 			(struct hbm_client_connect_request *)ishtp_msg;
729 		ishtp_hbm_fw_disconnect_req(dev, disconnect_req);
730 		break;
731 
732 	case FW_STOP_REQ_CMD:
733 		dev->hbm_state = ISHTP_HBM_STOPPED;
734 		break;
735 
736 	case DMA_BUFFER_ALLOC_RESPONSE:
737 		dev->ishtp_host_dma_enabled = 1;
738 		break;
739 
740 	case DMA_XFER:
741 		dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
742 		if (!dev->ishtp_host_dma_enabled) {
743 			dev_err(dev->devc,
744 				"DMA XFER requested but DMA is not enabled\n");
745 			break;
746 		}
747 		ishtp_hbm_dma_xfer(dev, dma_xfer);
748 		break;
749 
750 	case DMA_XFER_ACK:
751 		dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
752 		if (!dev->ishtp_host_dma_enabled ||
753 		    !dev->ishtp_host_dma_tx_buf) {
754 			dev_err(dev->devc,
755 				"DMA XFER acked but DMA Tx is not enabled\n");
756 			break;
757 		}
758 		ishtp_hbm_dma_xfer_ack(dev, dma_xfer);
759 		break;
760 
761 	default:
762 		dev_err(dev->devc, "unknown HBM: %u\n",
763 			(unsigned int)ishtp_msg->hbm_cmd);
764 
765 		break;
766 	}
767 }
768 
769 /**
770  * bh_hbm_work_fn() - HBM work function
771  * @work: work struct
772  *
773  * Bottom half processing work function (instead of thread handler)
774  * for processing hbm messages
775  */
776 void	bh_hbm_work_fn(struct work_struct *work)
777 {
778 	unsigned long	flags;
779 	struct ishtp_device	*dev;
780 	unsigned char	hbm[IPC_PAYLOAD_SIZE];
781 
782 	dev = container_of(work, struct ishtp_device, bh_hbm_work);
783 	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
784 	if (dev->rd_msg_fifo_head != dev->rd_msg_fifo_tail) {
785 		memcpy(hbm, dev->rd_msg_fifo + dev->rd_msg_fifo_head,
786 			IPC_PAYLOAD_SIZE);
787 		dev->rd_msg_fifo_head =
788 			(dev->rd_msg_fifo_head + IPC_PAYLOAD_SIZE) %
789 			(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
790 		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
791 		ishtp_hbm_dispatch(dev, (struct ishtp_bus_message *)hbm);
792 	} else {
793 		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
794 	}
795 }
796 
797 /**
798  * recv_hbm() - Receive HBM message
799  * @dev: ISHTP device instance
800  * @ishtp_hdr: received bus message
801  *
802  * Receive and process ISHTP bus messages in ISR context. This will schedule
803  * work function to process message
804  */
805 void	recv_hbm(struct ishtp_device *dev, struct ishtp_msg_hdr *ishtp_hdr)
806 {
807 	uint8_t	rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
808 	struct ishtp_bus_message	*ishtp_msg =
809 		(struct ishtp_bus_message *)rd_msg_buf;
810 	unsigned long	flags;
811 
812 	dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
813 
814 	/* Flow control - handle in place */
815 	if (ishtp_msg->hbm_cmd == ISHTP_FLOW_CONTROL_CMD) {
816 		struct hbm_flow_control *flow_control =
817 			(struct hbm_flow_control *)ishtp_msg;
818 		struct ishtp_cl *cl = NULL;
819 		unsigned long	flags, tx_flags;
820 
821 		spin_lock_irqsave(&dev->cl_list_lock, flags);
822 		list_for_each_entry(cl, &dev->cl_list, link) {
823 			if (cl->host_client_id == flow_control->host_addr &&
824 					cl->fw_client_id ==
825 					flow_control->fw_addr) {
826 				/*
827 				 * NOTE: It's valid only for counting
828 				 * flow-control implementation to receive a
829 				 * FC in the middle of sending. Meanwhile not
830 				 * supported
831 				 */
832 				if (cl->ishtp_flow_ctrl_creds)
833 					dev_err(dev->devc,
834 					 "recv extra FC from FW client %u (host client %u) (FC count was %d)\n",
835 					 (unsigned int)cl->fw_client_id,
836 					 (unsigned int)cl->host_client_id,
837 					 cl->ishtp_flow_ctrl_creds);
838 				else {
839 					++cl->ishtp_flow_ctrl_creds;
840 					++cl->ishtp_flow_ctrl_cnt;
841 					cl->last_ipc_acked = 1;
842 					spin_lock_irqsave(
843 							&cl->tx_list_spinlock,
844 							tx_flags);
845 					if (!list_empty(&cl->tx_list.list)) {
846 						/*
847 						 * start sending the first msg
848 						 *	= the callback function
849 						 */
850 						spin_unlock_irqrestore(
851 							&cl->tx_list_spinlock,
852 							tx_flags);
853 						ishtp_cl_send_msg(dev, cl);
854 					} else {
855 						spin_unlock_irqrestore(
856 							&cl->tx_list_spinlock,
857 							tx_flags);
858 					}
859 				}
860 				break;
861 			}
862 		}
863 		spin_unlock_irqrestore(&dev->cl_list_lock, flags);
864 		goto	eoi;
865 	}
866 
867 	/*
868 	 * Some messages that are safe for ISR processing and important
869 	 * to be done "quickly" and in-order, go here
870 	 */
871 	if (ishtp_msg->hbm_cmd == CLIENT_CONNECT_RES_CMD ||
872 			ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_RES_CMD ||
873 			ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_REQ_CMD ||
874 			ishtp_msg->hbm_cmd == DMA_XFER) {
875 		ishtp_hbm_dispatch(dev, ishtp_msg);
876 		goto	eoi;
877 	}
878 
879 	/*
880 	 * All other HBMs go here.
881 	 * We schedule HBMs for processing serially by using system wq,
882 	 * possibly there will be multiple HBMs scheduled at the same time.
883 	 */
884 	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
885 	if ((dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
886 			(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE) ==
887 			dev->rd_msg_fifo_head) {
888 		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
889 		dev_err(dev->devc, "BH buffer overflow, dropping HBM %u\n",
890 			(unsigned int)ishtp_msg->hbm_cmd);
891 		goto	eoi;
892 	}
893 	memcpy(dev->rd_msg_fifo + dev->rd_msg_fifo_tail, ishtp_msg,
894 		ishtp_hdr->length);
895 	dev->rd_msg_fifo_tail = (dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
896 		(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
897 	spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
898 	schedule_work(&dev->bh_hbm_work);
899 eoi:
900 	return;
901 }
902 
903 /**
904  * recv_fixed_cl_msg() - Receive fixed client message
905  * @dev: ISHTP device instance
906  * @ishtp_hdr: received bus message
907  *
908  * Receive and process ISHTP fixed client messages (address == 0)
909  * in ISR context
910  */
911 void recv_fixed_cl_msg(struct ishtp_device *dev,
912 	struct ishtp_msg_hdr *ishtp_hdr)
913 {
914 	uint8_t rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
915 
916 	dev->print_log(dev,
917 		"%s() got fixed client msg from client #%d\n",
918 		__func__, ishtp_hdr->fw_addr);
919 	dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
920 	if (ishtp_hdr->fw_addr == ISHTP_SYSTEM_STATE_CLIENT_ADDR) {
921 		struct ish_system_states_header *msg_hdr =
922 			(struct ish_system_states_header *)rd_msg_buf;
923 		if (msg_hdr->cmd == SYSTEM_STATE_SUBSCRIBE)
924 			ishtp_send_resume(dev);
925 		/* if FW request arrived here, the system is not suspended */
926 		else
927 			dev_err(dev->devc, "unknown fixed client msg [%02X]\n",
928 				msg_hdr->cmd);
929 	}
930 }
931 
932 /**
933  * fix_cl_hdr() - Initialize fixed client header
934  * @hdr: message header
935  * @length: length of message
936  * @cl_addr: Client address
937  *
938  * Initialize message header for fixed client
939  */
940 static inline void fix_cl_hdr(struct ishtp_msg_hdr *hdr, size_t length,
941 	uint8_t cl_addr)
942 {
943 	hdr->host_addr = 0;
944 	hdr->fw_addr = cl_addr;
945 	hdr->length = length;
946 	hdr->msg_complete = 1;
947 	hdr->reserved = 0;
948 }
949 
950 /*** Suspend and resume notification ***/
951 
952 static uint32_t current_state;
953 static uint32_t supported_states = 0 | SUSPEND_STATE_BIT;
954 
955 /**
956  * ishtp_send_suspend() - Send suspend message to FW
957  * @dev: ISHTP device instance
958  *
959  * Send suspend message to FW. This is useful for system freeze (non S3) case
960  */
961 void ishtp_send_suspend(struct ishtp_device *dev)
962 {
963 	struct ishtp_msg_hdr	ishtp_hdr;
964 	struct ish_system_states_status state_status_msg;
965 	const size_t len = sizeof(struct ish_system_states_status);
966 
967 	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
968 
969 	memset(&state_status_msg, 0, len);
970 	state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
971 	state_status_msg.supported_states = supported_states;
972 	current_state |= SUSPEND_STATE_BIT;
973 	dev->print_log(dev, "%s() sends SUSPEND notification\n", __func__);
974 	state_status_msg.states_status = current_state;
975 
976 	ishtp_write_message(dev, &ishtp_hdr,
977 		(unsigned char *)&state_status_msg);
978 }
979 EXPORT_SYMBOL(ishtp_send_suspend);
980 
981 /**
982  * ishtp_send_resume() - Send resume message to FW
983  * @dev: ISHTP device instance
984  *
985  * Send resume message to FW. This is useful for system freeze (non S3) case
986  */
987 void ishtp_send_resume(struct ishtp_device *dev)
988 {
989 	struct ishtp_msg_hdr	ishtp_hdr;
990 	struct ish_system_states_status state_status_msg;
991 	const size_t len = sizeof(struct ish_system_states_status);
992 
993 	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
994 
995 	memset(&state_status_msg, 0, len);
996 	state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
997 	state_status_msg.supported_states = supported_states;
998 	current_state &= ~SUSPEND_STATE_BIT;
999 	dev->print_log(dev, "%s() sends RESUME notification\n", __func__);
1000 	state_status_msg.states_status = current_state;
1001 
1002 	ishtp_write_message(dev, &ishtp_hdr,
1003 		(unsigned char *)&state_status_msg);
1004 }
1005 EXPORT_SYMBOL(ishtp_send_resume);
1006 
1007 /**
1008  * ishtp_query_subscribers() - Send query subscribers message
1009  * @dev: ISHTP device instance
1010  *
1011  * Send message to query subscribers
1012  */
1013 void ishtp_query_subscribers(struct ishtp_device *dev)
1014 {
1015 	struct ishtp_msg_hdr	ishtp_hdr;
1016 	struct ish_system_states_query_subscribers query_subscribers_msg;
1017 	const size_t len = sizeof(struct ish_system_states_query_subscribers);
1018 
1019 	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
1020 
1021 	memset(&query_subscribers_msg, 0, len);
1022 	query_subscribers_msg.hdr.cmd = SYSTEM_STATE_QUERY_SUBSCRIBERS;
1023 
1024 	ishtp_write_message(dev, &ishtp_hdr,
1025 		(unsigned char *)&query_subscribers_msg);
1026 }
1027