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 <linux/miscdevice.h>
23 #include "ishtp-dev.h"
24 #include "hbm.h"
25 #include "client.h"
26 
27 /**
28  * ishtp_hbm_fw_cl_allocate() - Allocate FW clients
29  * @dev: ISHTP device instance
30  *
31  * Allocates storage for fw clients
32  */
33 static void ishtp_hbm_fw_cl_allocate(struct ishtp_device *dev)
34 {
35 	struct ishtp_fw_client *clients;
36 	int b;
37 
38 	/* count how many ISH clients we have */
39 	for_each_set_bit(b, dev->fw_clients_map, ISHTP_CLIENTS_MAX)
40 		dev->fw_clients_num++;
41 
42 	if (dev->fw_clients_num <= 0)
43 		return;
44 
45 	/* allocate storage for fw clients representation */
46 	clients = kcalloc(dev->fw_clients_num, sizeof(struct ishtp_fw_client),
47 			  GFP_KERNEL);
48 	if (!clients) {
49 		dev->dev_state = ISHTP_DEV_RESETTING;
50 		ish_hw_reset(dev);
51 		return;
52 	}
53 	dev->fw_clients = clients;
54 }
55 
56 /**
57  * ishtp_hbm_cl_hdr() - construct client hbm header
58  * @cl: client
59  * @hbm_cmd: host bus message command
60  * @buf: buffer for cl header
61  * @len: buffer length
62  *
63  * Initialize HBM buffer
64  */
65 static inline void ishtp_hbm_cl_hdr(struct ishtp_cl *cl, uint8_t hbm_cmd,
66 	void *buf, size_t len)
67 {
68 	struct ishtp_hbm_cl_cmd *cmd = buf;
69 
70 	memset(cmd, 0, len);
71 
72 	cmd->hbm_cmd = hbm_cmd;
73 	cmd->host_addr = cl->host_client_id;
74 	cmd->fw_addr = cl->fw_client_id;
75 }
76 
77 /**
78  * ishtp_hbm_cl_addr_equal() - Compare client address
79  * @cl: client
80  * @buf: Client command buffer
81  *
82  * Compare client address with the address in command buffer
83  *
84  * Return: True if they have the same address
85  */
86 static inline bool ishtp_hbm_cl_addr_equal(struct ishtp_cl *cl, void *buf)
87 {
88 	struct ishtp_hbm_cl_cmd *cmd = buf;
89 
90 	return cl->host_client_id == cmd->host_addr &&
91 		cl->fw_client_id == cmd->fw_addr;
92 }
93 
94 /**
95  * ishtp_hbm_start_wait() - Wait for HBM start message
96  * @dev: ISHTP device instance
97  *
98  * Wait for HBM start message from firmware
99  *
100  * Return: 0 if HBM start is/was received else timeout error
101  */
102 int ishtp_hbm_start_wait(struct ishtp_device *dev)
103 {
104 	int ret;
105 
106 	if (dev->hbm_state > ISHTP_HBM_START)
107 		return 0;
108 
109 	dev_dbg(dev->devc, "Going to wait for ishtp start. hbm_state=%08X\n",
110 		dev->hbm_state);
111 	ret = wait_event_interruptible_timeout(dev->wait_hbm_recvd_msg,
112 					dev->hbm_state >= ISHTP_HBM_STARTED,
113 					(ISHTP_INTEROP_TIMEOUT * HZ));
114 
115 	dev_dbg(dev->devc,
116 		"Woke up from waiting for ishtp start. hbm_state=%08X\n",
117 		dev->hbm_state);
118 
119 	if (ret <= 0 && (dev->hbm_state <= ISHTP_HBM_START)) {
120 		dev->hbm_state = ISHTP_HBM_IDLE;
121 		dev_err(dev->devc,
122 		"waiting for ishtp start failed. ret=%d hbm_state=%08X\n",
123 			ret, dev->hbm_state);
124 		return -ETIMEDOUT;
125 	}
126 	return 0;
127 }
128 
129 /**
130  * ishtp_hbm_start_req() - Send HBM start message
131  * @dev: ISHTP device instance
132  *
133  * Send HBM start message to firmware
134  *
135  * Return: 0 if success else error code
136  */
137 int ishtp_hbm_start_req(struct ishtp_device *dev)
138 {
139 	struct ishtp_msg_hdr hdr;
140 	unsigned char data[128];
141 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
142 	struct hbm_host_version_request *start_req;
143 	const size_t len = sizeof(struct hbm_host_version_request);
144 
145 	ishtp_hbm_hdr(ishtp_hdr, len);
146 
147 	/* host start message */
148 	start_req = (struct hbm_host_version_request *)data;
149 	memset(start_req, 0, len);
150 	start_req->hbm_cmd = HOST_START_REQ_CMD;
151 	start_req->host_version.major_version = HBM_MAJOR_VERSION;
152 	start_req->host_version.minor_version = HBM_MINOR_VERSION;
153 
154 	/*
155 	 * (!) Response to HBM start may be so quick that this thread would get
156 	 * preempted BEFORE managing to set hbm_state = ISHTP_HBM_START.
157 	 * So set it at first, change back to ISHTP_HBM_IDLE upon failure
158 	 */
159 	dev->hbm_state = ISHTP_HBM_START;
160 	if (ishtp_write_message(dev, ishtp_hdr, data)) {
161 		dev_err(dev->devc, "version message send failed\n");
162 		dev->dev_state = ISHTP_DEV_RESETTING;
163 		dev->hbm_state = ISHTP_HBM_IDLE;
164 		ish_hw_reset(dev);
165 		return -ENODEV;
166 	}
167 
168 	return 0;
169 }
170 
171 /**
172  * ishtp_hbm_enum_clients_req() - Send client enum req
173  * @dev: ISHTP device instance
174  *
175  * Send enumeration client request message
176  *
177  * Return: 0 if success else error code
178  */
179 void ishtp_hbm_enum_clients_req(struct ishtp_device *dev)
180 {
181 	struct ishtp_msg_hdr hdr;
182 	unsigned char data[128];
183 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
184 	struct hbm_host_enum_request *enum_req;
185 	const size_t len = sizeof(struct hbm_host_enum_request);
186 
187 	/* enumerate clients */
188 	ishtp_hbm_hdr(ishtp_hdr, len);
189 
190 	enum_req = (struct hbm_host_enum_request *)data;
191 	memset(enum_req, 0, len);
192 	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
193 
194 	if (ishtp_write_message(dev, ishtp_hdr, data)) {
195 		dev->dev_state = ISHTP_DEV_RESETTING;
196 		dev_err(dev->devc, "enumeration request send failed\n");
197 		ish_hw_reset(dev);
198 	}
199 	dev->hbm_state = ISHTP_HBM_ENUM_CLIENTS;
200 }
201 
202 /**
203  * ishtp_hbm_prop_req() - Request property
204  * @dev: ISHTP device instance
205  *
206  * Request property for a single client
207  *
208  * Return: 0 if success else error code
209  */
210 static int ishtp_hbm_prop_req(struct ishtp_device *dev)
211 {
212 
213 	struct ishtp_msg_hdr hdr;
214 	unsigned char data[128];
215 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
216 	struct hbm_props_request *prop_req;
217 	const size_t len = sizeof(struct hbm_props_request);
218 	unsigned long next_client_index;
219 	uint8_t client_num;
220 
221 	client_num = dev->fw_client_presentation_num;
222 
223 	next_client_index = find_next_bit(dev->fw_clients_map,
224 		ISHTP_CLIENTS_MAX, dev->fw_client_index);
225 
226 	/* We got all client properties */
227 	if (next_client_index == ISHTP_CLIENTS_MAX) {
228 		dev->hbm_state = ISHTP_HBM_WORKING;
229 		dev->dev_state = ISHTP_DEV_ENABLED;
230 
231 		for (dev->fw_client_presentation_num = 1;
232 			dev->fw_client_presentation_num < client_num + 1;
233 				++dev->fw_client_presentation_num)
234 			/* Add new client device */
235 			ishtp_bus_new_client(dev);
236 		return 0;
237 	}
238 
239 	dev->fw_clients[client_num].client_id = next_client_index;
240 
241 	ishtp_hbm_hdr(ishtp_hdr, len);
242 	prop_req = (struct hbm_props_request *)data;
243 
244 	memset(prop_req, 0, sizeof(struct hbm_props_request));
245 
246 	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
247 	prop_req->address = next_client_index;
248 
249 	if (ishtp_write_message(dev, ishtp_hdr, data)) {
250 		dev->dev_state = ISHTP_DEV_RESETTING;
251 		dev_err(dev->devc, "properties request send failed\n");
252 		ish_hw_reset(dev);
253 		return -EIO;
254 	}
255 
256 	dev->fw_client_index = next_client_index;
257 
258 	return 0;
259 }
260 
261 /**
262  * ishtp_hbm_stop_req() - Send HBM stop
263  * @dev: ISHTP device instance
264  *
265  * Send stop request message
266  */
267 static void ishtp_hbm_stop_req(struct ishtp_device *dev)
268 {
269 	struct ishtp_msg_hdr hdr;
270 	unsigned char data[128];
271 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
272 	struct hbm_host_stop_request *req;
273 	const size_t len = sizeof(struct hbm_host_stop_request);
274 
275 	ishtp_hbm_hdr(ishtp_hdr, len);
276 	req = (struct hbm_host_stop_request *)data;
277 
278 	memset(req, 0, sizeof(struct hbm_host_stop_request));
279 	req->hbm_cmd = HOST_STOP_REQ_CMD;
280 	req->reason = DRIVER_STOP_REQUEST;
281 
282 	ishtp_write_message(dev, ishtp_hdr, data);
283 }
284 
285 /**
286  * ishtp_hbm_cl_flow_control_req() - Send flow control request
287  * @dev: ISHTP device instance
288  * @cl: ISHTP client instance
289  *
290  * Send flow control request
291  *
292  * Return: 0 if success else error code
293  */
294 int ishtp_hbm_cl_flow_control_req(struct ishtp_device *dev,
295 				  struct ishtp_cl *cl)
296 {
297 	struct ishtp_msg_hdr hdr;
298 	unsigned char data[128];
299 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
300 	const size_t len = sizeof(struct hbm_flow_control);
301 	int	rv;
302 	unsigned int	num_frags;
303 	unsigned long	flags;
304 
305 	spin_lock_irqsave(&cl->fc_spinlock, flags);
306 	ishtp_hbm_hdr(ishtp_hdr, len);
307 	ishtp_hbm_cl_hdr(cl, ISHTP_FLOW_CONTROL_CMD, data, len);
308 
309 	/*
310 	 * Sync possible race when RB recycle and packet receive paths
311 	 * both try to send an out FC
312 	 */
313 	if (cl->out_flow_ctrl_creds) {
314 		spin_unlock_irqrestore(&cl->fc_spinlock, flags);
315 		return	0;
316 	}
317 
318 	num_frags = cl->recv_msg_num_frags;
319 	cl->recv_msg_num_frags = 0;
320 
321 	rv = ishtp_write_message(dev, ishtp_hdr, data);
322 	if (!rv) {
323 		++cl->out_flow_ctrl_creds;
324 		++cl->out_flow_ctrl_cnt;
325 		getnstimeofday(&cl->ts_out_fc);
326 		if (cl->ts_rx.tv_sec && cl->ts_rx.tv_nsec) {
327 			struct timespec ts_diff;
328 
329 			ts_diff = timespec_sub(cl->ts_out_fc, cl->ts_rx);
330 			if (timespec_compare(&ts_diff, &cl->ts_max_fc_delay)
331 					> 0)
332 				cl->ts_max_fc_delay = ts_diff;
333 		}
334 	} else {
335 		++cl->err_send_fc;
336 	}
337 
338 	spin_unlock_irqrestore(&cl->fc_spinlock, flags);
339 	return	rv;
340 }
341 
342 /**
343  * ishtp_hbm_cl_disconnect_req() - Send disconnect request
344  * @dev: ISHTP device instance
345  * @cl: ISHTP client instance
346  *
347  * Send disconnect message to fw
348  *
349  * Return: 0 if success else error code
350  */
351 int ishtp_hbm_cl_disconnect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
352 {
353 	struct ishtp_msg_hdr hdr;
354 	unsigned char data[128];
355 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
356 	const size_t len = sizeof(struct hbm_client_connect_request);
357 
358 	ishtp_hbm_hdr(ishtp_hdr, len);
359 	ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_REQ_CMD, data, len);
360 
361 	return ishtp_write_message(dev, ishtp_hdr, data);
362 }
363 
364 /**
365  * ishtp_hbm_cl_disconnect_res() - Get disconnect response
366  * @dev: ISHTP device instance
367  * @rs: Response message
368  *
369  * Received disconnect response from fw
370  */
371 static void ishtp_hbm_cl_disconnect_res(struct ishtp_device *dev,
372 	struct hbm_client_connect_response *rs)
373 {
374 	struct ishtp_cl *cl = NULL;
375 	unsigned long	flags;
376 
377 	spin_lock_irqsave(&dev->cl_list_lock, flags);
378 	list_for_each_entry(cl, &dev->cl_list, link) {
379 		if (!rs->status && ishtp_hbm_cl_addr_equal(cl, rs)) {
380 			cl->state = ISHTP_CL_DISCONNECTED;
381 			wake_up_interruptible(&cl->wait_ctrl_res);
382 			break;
383 		}
384 	}
385 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
386 }
387 
388 /**
389  * ishtp_hbm_cl_connect_req() - Send connect request
390  * @dev: ISHTP device instance
391  * @cl: client device instance
392  *
393  * Send connection request to specific fw client
394  *
395  * Return: 0 if success else error code
396  */
397 int ishtp_hbm_cl_connect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
398 {
399 	struct ishtp_msg_hdr hdr;
400 	unsigned char data[128];
401 	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
402 	const size_t len = sizeof(struct hbm_client_connect_request);
403 
404 	ishtp_hbm_hdr(ishtp_hdr, len);
405 	ishtp_hbm_cl_hdr(cl, CLIENT_CONNECT_REQ_CMD, data, len);
406 
407 	return ishtp_write_message(dev, ishtp_hdr, data);
408 }
409 
410 /**
411  * ishtp_hbm_cl_connect_res() - Get connect response
412  * @dev: ISHTP device instance
413  * @rs: Response message
414  *
415  * Received connect response from fw
416  */
417 static void ishtp_hbm_cl_connect_res(struct ishtp_device *dev,
418 	struct hbm_client_connect_response *rs)
419 {
420 	struct ishtp_cl *cl = NULL;
421 	unsigned long	flags;
422 
423 	spin_lock_irqsave(&dev->cl_list_lock, flags);
424 	list_for_each_entry(cl, &dev->cl_list, link) {
425 		if (ishtp_hbm_cl_addr_equal(cl, rs)) {
426 			if (!rs->status) {
427 				cl->state = ISHTP_CL_CONNECTED;
428 				cl->status = 0;
429 			} else {
430 				cl->state = ISHTP_CL_DISCONNECTED;
431 				cl->status = -ENODEV;
432 			}
433 			wake_up_interruptible(&cl->wait_ctrl_res);
434 			break;
435 		}
436 	}
437 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
438 }
439 
440 /**
441  * ishtp_client_disconnect_request() - Receive disconnect request
442  * @dev: ISHTP device instance
443  * @disconnect_req: disconnect request structure
444  *
445  * Disconnect request bus message from the fw. Send diconnect response.
446  */
447 static void ishtp_hbm_fw_disconnect_req(struct ishtp_device *dev,
448 	struct hbm_client_connect_request *disconnect_req)
449 {
450 	struct ishtp_cl *cl;
451 	const size_t len = sizeof(struct hbm_client_connect_response);
452 	unsigned long	flags;
453 	struct ishtp_msg_hdr hdr;
454 	unsigned char data[4];	/* All HBM messages are 4 bytes */
455 
456 	spin_lock_irqsave(&dev->cl_list_lock, flags);
457 	list_for_each_entry(cl, &dev->cl_list, link) {
458 		if (ishtp_hbm_cl_addr_equal(cl, disconnect_req)) {
459 			cl->state = ISHTP_CL_DISCONNECTED;
460 
461 			/* send disconnect response */
462 			ishtp_hbm_hdr(&hdr, len);
463 			ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD, data,
464 				len);
465 			ishtp_write_message(dev, &hdr, data);
466 			break;
467 		}
468 	}
469 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
470 }
471 
472 /**
473  * ishtp_hbm_dma_xfer_ack(() - Receive transfer ACK
474  * @dev: ISHTP device instance
475  * @dma_xfer: HBM transfer message
476  *
477  * Receive ack for ISHTP-over-DMA client message
478  */
479 static void ishtp_hbm_dma_xfer_ack(struct ishtp_device *dev,
480 				   struct dma_xfer_hbm *dma_xfer)
481 {
482 	void	*msg;
483 	uint64_t	offs;
484 	struct ishtp_msg_hdr	*ishtp_hdr =
485 		(struct ishtp_msg_hdr *)&dev->ishtp_msg_hdr;
486 	unsigned int	msg_offs;
487 	struct ishtp_cl *cl;
488 
489 	for (msg_offs = 0; msg_offs < ishtp_hdr->length;
490 		msg_offs += sizeof(struct dma_xfer_hbm)) {
491 		offs = dma_xfer->msg_addr - dev->ishtp_host_dma_tx_buf_phys;
492 		if (offs > dev->ishtp_host_dma_tx_buf_size) {
493 			dev_err(dev->devc, "Bad DMA Tx ack message address\n");
494 			return;
495 		}
496 		if (dma_xfer->msg_length >
497 				dev->ishtp_host_dma_tx_buf_size - offs) {
498 			dev_err(dev->devc, "Bad DMA Tx ack message size\n");
499 			return;
500 		}
501 
502 		/* logical address of the acked mem */
503 		msg = (unsigned char *)dev->ishtp_host_dma_tx_buf + offs;
504 		ishtp_cl_release_dma_acked_mem(dev, msg, dma_xfer->msg_length);
505 
506 		list_for_each_entry(cl, &dev->cl_list, link) {
507 			if (cl->fw_client_id == dma_xfer->fw_client_id &&
508 			    cl->host_client_id == dma_xfer->host_client_id)
509 				/*
510 				 * in case that a single ack may be sent
511 				 * over several dma transfers, and the last msg
512 				 * addr was inside the acked memory, but not in
513 				 * its start
514 				 */
515 				if (cl->last_dma_addr >=
516 							(unsigned char *)msg &&
517 						cl->last_dma_addr <
518 						(unsigned char *)msg +
519 						dma_xfer->msg_length) {
520 					cl->last_dma_acked = 1;
521 
522 					if (!list_empty(&cl->tx_list.list) &&
523 						cl->ishtp_flow_ctrl_creds) {
524 						/*
525 						 * start sending the first msg
526 						 */
527 						ishtp_cl_send_msg(dev, cl);
528 					}
529 				}
530 		}
531 		++dma_xfer;
532 	}
533 }
534 
535 /**
536  * ishtp_hbm_dma_xfer() - Receive DMA transfer message
537  * @dev: ISHTP device instance
538  * @dma_xfer: HBM transfer message
539  *
540  * Receive ISHTP-over-DMA client message
541  */
542 static void ishtp_hbm_dma_xfer(struct ishtp_device *dev,
543 			       struct dma_xfer_hbm *dma_xfer)
544 {
545 	void	*msg;
546 	uint64_t	offs;
547 	struct ishtp_msg_hdr	hdr;
548 	struct ishtp_msg_hdr	*ishtp_hdr =
549 		(struct ishtp_msg_hdr *) &dev->ishtp_msg_hdr;
550 	struct dma_xfer_hbm	*prm = dma_xfer;
551 	unsigned int	msg_offs;
552 
553 	for (msg_offs = 0; msg_offs < ishtp_hdr->length;
554 		msg_offs += sizeof(struct dma_xfer_hbm)) {
555 
556 		offs = dma_xfer->msg_addr - dev->ishtp_host_dma_rx_buf_phys;
557 		if (offs > dev->ishtp_host_dma_rx_buf_size) {
558 			dev_err(dev->devc, "Bad DMA Rx message address\n");
559 			return;
560 		}
561 		if (dma_xfer->msg_length >
562 				dev->ishtp_host_dma_rx_buf_size - offs) {
563 			dev_err(dev->devc, "Bad DMA Rx message size\n");
564 			return;
565 		}
566 		msg = dev->ishtp_host_dma_rx_buf + offs;
567 		recv_ishtp_cl_msg_dma(dev, msg, dma_xfer);
568 		dma_xfer->hbm = DMA_XFER_ACK;	/* Prepare for response */
569 		++dma_xfer;
570 	}
571 
572 	/* Send DMA_XFER_ACK [...] */
573 	ishtp_hbm_hdr(&hdr, ishtp_hdr->length);
574 	ishtp_write_message(dev, &hdr, (unsigned char *)prm);
575 }
576 
577 /**
578  * ishtp_hbm_dispatch() - HBM dispatch function
579  * @dev: ISHTP device instance
580  * @hdr: bus message
581  *
582  * Bottom half read routine after ISR to handle the read bus message cmd
583  * processing
584  */
585 void ishtp_hbm_dispatch(struct ishtp_device *dev,
586 			struct ishtp_bus_message *hdr)
587 {
588 	struct ishtp_bus_message *ishtp_msg;
589 	struct ishtp_fw_client *fw_client;
590 	struct hbm_host_version_response *version_res;
591 	struct hbm_client_connect_response *connect_res;
592 	struct hbm_client_connect_response *disconnect_res;
593 	struct hbm_client_connect_request *disconnect_req;
594 	struct hbm_props_response *props_res;
595 	struct hbm_host_enum_response *enum_res;
596 	struct ishtp_msg_hdr ishtp_hdr;
597 	struct dma_alloc_notify	dma_alloc_notify;
598 	struct dma_xfer_hbm	*dma_xfer;
599 
600 	ishtp_msg = hdr;
601 
602 	switch (ishtp_msg->hbm_cmd) {
603 	case HOST_START_RES_CMD:
604 		version_res = (struct hbm_host_version_response *)ishtp_msg;
605 		if (!version_res->host_version_supported) {
606 			dev->version = version_res->fw_max_version;
607 
608 			dev->hbm_state = ISHTP_HBM_STOPPED;
609 			ishtp_hbm_stop_req(dev);
610 			return;
611 		}
612 
613 		dev->version.major_version = HBM_MAJOR_VERSION;
614 		dev->version.minor_version = HBM_MINOR_VERSION;
615 		if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
616 				dev->hbm_state == ISHTP_HBM_START) {
617 			dev->hbm_state = ISHTP_HBM_STARTED;
618 			ishtp_hbm_enum_clients_req(dev);
619 		} else {
620 			dev_err(dev->devc,
621 				"reset: wrong host start response\n");
622 			/* BUG: why do we arrive here? */
623 			ish_hw_reset(dev);
624 			return;
625 		}
626 
627 		wake_up_interruptible(&dev->wait_hbm_recvd_msg);
628 		break;
629 
630 	case CLIENT_CONNECT_RES_CMD:
631 		connect_res = (struct hbm_client_connect_response *)ishtp_msg;
632 		ishtp_hbm_cl_connect_res(dev, connect_res);
633 		break;
634 
635 	case CLIENT_DISCONNECT_RES_CMD:
636 		disconnect_res =
637 			(struct hbm_client_connect_response *)ishtp_msg;
638 		ishtp_hbm_cl_disconnect_res(dev, disconnect_res);
639 		break;
640 
641 	case HOST_CLIENT_PROPERTIES_RES_CMD:
642 		props_res = (struct hbm_props_response *)ishtp_msg;
643 		fw_client = &dev->fw_clients[dev->fw_client_presentation_num];
644 
645 		if (props_res->status || !dev->fw_clients) {
646 			dev_err(dev->devc,
647 			"reset: properties response hbm wrong status\n");
648 			ish_hw_reset(dev);
649 			return;
650 		}
651 
652 		if (fw_client->client_id != props_res->address) {
653 			dev_err(dev->devc,
654 				"reset: host properties response address mismatch [%02X %02X]\n",
655 				fw_client->client_id, props_res->address);
656 			ish_hw_reset(dev);
657 			return;
658 		}
659 
660 		if (dev->dev_state != ISHTP_DEV_INIT_CLIENTS ||
661 			dev->hbm_state != ISHTP_HBM_CLIENT_PROPERTIES) {
662 			dev_err(dev->devc,
663 				"reset: unexpected properties response\n");
664 			ish_hw_reset(dev);
665 			return;
666 		}
667 
668 		fw_client->props = props_res->client_properties;
669 		dev->fw_client_index++;
670 		dev->fw_client_presentation_num++;
671 
672 		/* request property for the next client */
673 		ishtp_hbm_prop_req(dev);
674 
675 		if (dev->dev_state != ISHTP_DEV_ENABLED)
676 			break;
677 
678 		if (!ishtp_use_dma_transfer())
679 			break;
680 
681 		dev_dbg(dev->devc, "Requesting to use DMA\n");
682 		ishtp_cl_alloc_dma_buf(dev);
683 		if (dev->ishtp_host_dma_rx_buf) {
684 			const size_t len = sizeof(dma_alloc_notify);
685 
686 			memset(&dma_alloc_notify, 0, sizeof(dma_alloc_notify));
687 			dma_alloc_notify.hbm = DMA_BUFFER_ALLOC_NOTIFY;
688 			dma_alloc_notify.buf_size =
689 					dev->ishtp_host_dma_rx_buf_size;
690 			dma_alloc_notify.buf_address =
691 					dev->ishtp_host_dma_rx_buf_phys;
692 			ishtp_hbm_hdr(&ishtp_hdr, len);
693 			ishtp_write_message(dev, &ishtp_hdr,
694 				(unsigned char *)&dma_alloc_notify);
695 		}
696 
697 		break;
698 
699 	case HOST_ENUM_RES_CMD:
700 		enum_res = (struct hbm_host_enum_response *) ishtp_msg;
701 		memcpy(dev->fw_clients_map, enum_res->valid_addresses, 32);
702 		if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
703 			dev->hbm_state == ISHTP_HBM_ENUM_CLIENTS) {
704 			dev->fw_client_presentation_num = 0;
705 			dev->fw_client_index = 0;
706 
707 			ishtp_hbm_fw_cl_allocate(dev);
708 			dev->hbm_state = ISHTP_HBM_CLIENT_PROPERTIES;
709 
710 			/* first property request */
711 			ishtp_hbm_prop_req(dev);
712 		} else {
713 			dev_err(dev->devc,
714 			      "reset: unexpected enumeration response hbm\n");
715 			ish_hw_reset(dev);
716 			return;
717 		}
718 		break;
719 
720 	case HOST_STOP_RES_CMD:
721 		if (dev->hbm_state != ISHTP_HBM_STOPPED)
722 			dev_err(dev->devc, "unexpected stop response\n");
723 
724 		dev->dev_state = ISHTP_DEV_DISABLED;
725 		dev_info(dev->devc, "reset: FW stop response\n");
726 		ish_hw_reset(dev);
727 		break;
728 
729 	case CLIENT_DISCONNECT_REQ_CMD:
730 		/* search for client */
731 		disconnect_req =
732 			(struct hbm_client_connect_request *)ishtp_msg;
733 		ishtp_hbm_fw_disconnect_req(dev, disconnect_req);
734 		break;
735 
736 	case FW_STOP_REQ_CMD:
737 		dev->hbm_state = ISHTP_HBM_STOPPED;
738 		break;
739 
740 	case DMA_BUFFER_ALLOC_RESPONSE:
741 		dev->ishtp_host_dma_enabled = 1;
742 		break;
743 
744 	case DMA_XFER:
745 		dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
746 		if (!dev->ishtp_host_dma_enabled) {
747 			dev_err(dev->devc,
748 				"DMA XFER requested but DMA is not enabled\n");
749 			break;
750 		}
751 		ishtp_hbm_dma_xfer(dev, dma_xfer);
752 		break;
753 
754 	case DMA_XFER_ACK:
755 		dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
756 		if (!dev->ishtp_host_dma_enabled ||
757 		    !dev->ishtp_host_dma_tx_buf) {
758 			dev_err(dev->devc,
759 				"DMA XFER acked but DMA Tx is not enabled\n");
760 			break;
761 		}
762 		ishtp_hbm_dma_xfer_ack(dev, dma_xfer);
763 		break;
764 
765 	default:
766 		dev_err(dev->devc, "unknown HBM: %u\n",
767 			(unsigned int)ishtp_msg->hbm_cmd);
768 
769 		break;
770 	}
771 }
772 
773 /**
774  * bh_hbm_work_fn() - HBM work function
775  * @work: work struct
776  *
777  * Bottom half processing work function (instead of thread handler)
778  * for processing hbm messages
779  */
780 void	bh_hbm_work_fn(struct work_struct *work)
781 {
782 	unsigned long	flags;
783 	struct ishtp_device	*dev;
784 	unsigned char	hbm[IPC_PAYLOAD_SIZE];
785 
786 	dev = container_of(work, struct ishtp_device, bh_hbm_work);
787 	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
788 	if (dev->rd_msg_fifo_head != dev->rd_msg_fifo_tail) {
789 		memcpy(hbm, dev->rd_msg_fifo + dev->rd_msg_fifo_head,
790 			IPC_PAYLOAD_SIZE);
791 		dev->rd_msg_fifo_head =
792 			(dev->rd_msg_fifo_head + IPC_PAYLOAD_SIZE) %
793 			(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
794 		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
795 		ishtp_hbm_dispatch(dev, (struct ishtp_bus_message *)hbm);
796 	} else {
797 		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
798 	}
799 }
800 
801 /**
802  * recv_hbm() - Receive HBM message
803  * @dev: ISHTP device instance
804  * @ishtp_hdr: received bus message
805  *
806  * Receive and process ISHTP bus messages in ISR context. This will schedule
807  * work function to process message
808  */
809 void	recv_hbm(struct ishtp_device *dev, struct ishtp_msg_hdr *ishtp_hdr)
810 {
811 	uint8_t	rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
812 	struct ishtp_bus_message	*ishtp_msg =
813 		(struct ishtp_bus_message *)rd_msg_buf;
814 	unsigned long	flags;
815 
816 	dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
817 
818 	/* Flow control - handle in place */
819 	if (ishtp_msg->hbm_cmd == ISHTP_FLOW_CONTROL_CMD) {
820 		struct hbm_flow_control *flow_control =
821 			(struct hbm_flow_control *)ishtp_msg;
822 		struct ishtp_cl *cl = NULL;
823 		unsigned long	flags, tx_flags;
824 
825 		spin_lock_irqsave(&dev->cl_list_lock, flags);
826 		list_for_each_entry(cl, &dev->cl_list, link) {
827 			if (cl->host_client_id == flow_control->host_addr &&
828 					cl->fw_client_id ==
829 					flow_control->fw_addr) {
830 				/*
831 				 * NOTE: It's valid only for counting
832 				 * flow-control implementation to receive a
833 				 * FC in the middle of sending. Meanwhile not
834 				 * supported
835 				 */
836 				if (cl->ishtp_flow_ctrl_creds)
837 					dev_err(dev->devc,
838 					 "recv extra FC from FW client %u (host client %u) (FC count was %d)\n",
839 					 (unsigned int)cl->fw_client_id,
840 					 (unsigned int)cl->host_client_id,
841 					 cl->ishtp_flow_ctrl_creds);
842 				else {
843 					++cl->ishtp_flow_ctrl_creds;
844 					++cl->ishtp_flow_ctrl_cnt;
845 					cl->last_ipc_acked = 1;
846 					spin_lock_irqsave(
847 							&cl->tx_list_spinlock,
848 							tx_flags);
849 					if (!list_empty(&cl->tx_list.list)) {
850 						/*
851 						 * start sending the first msg
852 						 *	= the callback function
853 						 */
854 						spin_unlock_irqrestore(
855 							&cl->tx_list_spinlock,
856 							tx_flags);
857 						ishtp_cl_send_msg(dev, cl);
858 					} else {
859 						spin_unlock_irqrestore(
860 							&cl->tx_list_spinlock,
861 							tx_flags);
862 					}
863 				}
864 				break;
865 			}
866 		}
867 		spin_unlock_irqrestore(&dev->cl_list_lock, flags);
868 		goto	eoi;
869 	}
870 
871 	/*
872 	 * Some messages that are safe for ISR processing and important
873 	 * to be done "quickly" and in-order, go here
874 	 */
875 	if (ishtp_msg->hbm_cmd == CLIENT_CONNECT_RES_CMD ||
876 			ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_RES_CMD ||
877 			ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_REQ_CMD ||
878 			ishtp_msg->hbm_cmd == DMA_XFER) {
879 		ishtp_hbm_dispatch(dev, ishtp_msg);
880 		goto	eoi;
881 	}
882 
883 	/*
884 	 * All other HBMs go here.
885 	 * We schedule HBMs for processing serially by using system wq,
886 	 * possibly there will be multiple HBMs scheduled at the same time.
887 	 */
888 	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
889 	if ((dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
890 			(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE) ==
891 			dev->rd_msg_fifo_head) {
892 		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
893 		dev_err(dev->devc, "BH buffer overflow, dropping HBM %u\n",
894 			(unsigned int)ishtp_msg->hbm_cmd);
895 		goto	eoi;
896 	}
897 	memcpy(dev->rd_msg_fifo + dev->rd_msg_fifo_tail, ishtp_msg,
898 		ishtp_hdr->length);
899 	dev->rd_msg_fifo_tail = (dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
900 		(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
901 	spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
902 	schedule_work(&dev->bh_hbm_work);
903 eoi:
904 	return;
905 }
906 
907 /**
908  * recv_fixed_cl_msg() - Receive fixed client message
909  * @dev: ISHTP device instance
910  * @ishtp_hdr: received bus message
911  *
912  * Receive and process ISHTP fixed client messages (address == 0)
913  * in ISR context
914  */
915 void recv_fixed_cl_msg(struct ishtp_device *dev,
916 	struct ishtp_msg_hdr *ishtp_hdr)
917 {
918 	uint8_t rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
919 
920 	dev->print_log(dev,
921 		"%s() got fixed client msg from client #%d\n",
922 		__func__, ishtp_hdr->fw_addr);
923 	dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
924 	if (ishtp_hdr->fw_addr == ISHTP_SYSTEM_STATE_CLIENT_ADDR) {
925 		struct ish_system_states_header *msg_hdr =
926 			(struct ish_system_states_header *)rd_msg_buf;
927 		if (msg_hdr->cmd == SYSTEM_STATE_SUBSCRIBE)
928 			ishtp_send_resume(dev);
929 		/* if FW request arrived here, the system is not suspended */
930 		else
931 			dev_err(dev->devc, "unknown fixed client msg [%02X]\n",
932 				msg_hdr->cmd);
933 	}
934 }
935 
936 /**
937  * fix_cl_hdr() - Initialize fixed client header
938  * @hdr: message header
939  * @length: length of message
940  * @cl_addr: Client address
941  *
942  * Initialize message header for fixed client
943  */
944 static inline void fix_cl_hdr(struct ishtp_msg_hdr *hdr, size_t length,
945 	uint8_t cl_addr)
946 {
947 	hdr->host_addr = 0;
948 	hdr->fw_addr = cl_addr;
949 	hdr->length = length;
950 	hdr->msg_complete = 1;
951 	hdr->reserved = 0;
952 }
953 
954 /*** Suspend and resume notification ***/
955 
956 static uint32_t current_state;
957 static uint32_t supported_states = 0 | SUSPEND_STATE_BIT;
958 
959 /**
960  * ishtp_send_suspend() - Send suspend message to FW
961  * @dev: ISHTP device instance
962  *
963  * Send suspend message to FW. This is useful for system freeze (non S3) case
964  */
965 void ishtp_send_suspend(struct ishtp_device *dev)
966 {
967 	struct ishtp_msg_hdr	ishtp_hdr;
968 	struct ish_system_states_status state_status_msg;
969 	const size_t len = sizeof(struct ish_system_states_status);
970 
971 	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
972 
973 	memset(&state_status_msg, 0, len);
974 	state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
975 	state_status_msg.supported_states = supported_states;
976 	current_state |= SUSPEND_STATE_BIT;
977 	dev->print_log(dev, "%s() sends SUSPEND notification\n", __func__);
978 	state_status_msg.states_status = current_state;
979 
980 	ishtp_write_message(dev, &ishtp_hdr,
981 		(unsigned char *)&state_status_msg);
982 }
983 EXPORT_SYMBOL(ishtp_send_suspend);
984 
985 /**
986  * ishtp_send_resume() - Send resume message to FW
987  * @dev: ISHTP device instance
988  *
989  * Send resume message to FW. This is useful for system freeze (non S3) case
990  */
991 void ishtp_send_resume(struct ishtp_device *dev)
992 {
993 	struct ishtp_msg_hdr	ishtp_hdr;
994 	struct ish_system_states_status state_status_msg;
995 	const size_t len = sizeof(struct ish_system_states_status);
996 
997 	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
998 
999 	memset(&state_status_msg, 0, len);
1000 	state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
1001 	state_status_msg.supported_states = supported_states;
1002 	current_state &= ~SUSPEND_STATE_BIT;
1003 	dev->print_log(dev, "%s() sends RESUME notification\n", __func__);
1004 	state_status_msg.states_status = current_state;
1005 
1006 	ishtp_write_message(dev, &ishtp_hdr,
1007 		(unsigned char *)&state_status_msg);
1008 }
1009 EXPORT_SYMBOL(ishtp_send_resume);
1010 
1011 /**
1012  * ishtp_query_subscribers() - Send query subscribers message
1013  * @dev: ISHTP device instance
1014  *
1015  * Send message to query subscribers
1016  */
1017 void ishtp_query_subscribers(struct ishtp_device *dev)
1018 {
1019 	struct ishtp_msg_hdr	ishtp_hdr;
1020 	struct ish_system_states_query_subscribers query_subscribers_msg;
1021 	const size_t len = sizeof(struct ish_system_states_query_subscribers);
1022 
1023 	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
1024 
1025 	memset(&query_subscribers_msg, 0, len);
1026 	query_subscribers_msg.hdr.cmd = SYSTEM_STATE_QUERY_SUBSCRIBERS;
1027 
1028 	ishtp_write_message(dev, &ishtp_hdr,
1029 		(unsigned char *)&query_subscribers_msg);
1030 }
1031