interrupt.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2003-2018, Intel Corporation. All rights reserved.
  4 * Intel Management Engine Interface (Intel MEI) Linux driver
  5 */
  6
  7#include <linux/export.h>
  8#include <linux/kthread.h>
  9#include <linux/interrupt.h>
 10#include <linux/fs.h>
 11#include <linux/jiffies.h>
 12#include <linux/slab.h>
 13#include <linux/pm_runtime.h>
 14
 15#include <linux/mei.h>
 16
 17#include "mei_dev.h"
 18#include "hbm.h"
 19#include "client.h"
 20
 21
 22/**
 23 * mei_irq_compl_handler - dispatch complete handlers
 24 *	for the completed callbacks
 25 *
 26 * @dev: mei device
 27 * @cmpl_list: list of completed cbs
 28 */
 29void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
 30{
 31	struct mei_cl_cb *cb, *next;
 32	struct mei_cl *cl;
 33
 34	list_for_each_entry_safe(cb, next, cmpl_list, list) {
 35		cl = cb->cl;
 36		list_del_init(&cb->list);
 37
 38		cl_dbg(dev, cl, "completing call back.\n");
 39		mei_cl_complete(cl, cb);
 40	}
 41}
 42EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
 43
 44/**
 45 * mei_cl_hbm_equal - check if hbm is addressed to the client
 46 *
 47 * @cl: host client
 48 * @mei_hdr: header of mei client message
 49 *
 50 * Return: true if matches, false otherwise
 51 */
 52static inline int mei_cl_hbm_equal(struct mei_cl *cl,
 53			struct mei_msg_hdr *mei_hdr)
 54{
 55	return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
 56		mei_cl_me_id(cl) == mei_hdr->me_addr;
 57}
 58
 59/**
 60 * mei_irq_discard_msg  - discard received message
 61 *
 62 * @dev: mei device
 63 * @hdr: message header
 64 * @discard_len: the length of the message to discard (excluding header)
 65 */
 66static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr,
 67				size_t discard_len)
 68{
 69	if (hdr->dma_ring) {
 70		mei_dma_ring_read(dev, NULL,
 71				  hdr->extension[dev->rd_msg_hdr_count - 2]);
 72		discard_len = 0;
 73	}
 74	/*
 75	 * no need to check for size as it is guaranteed
 76	 * that length fits into rd_msg_buf
 77	 */
 78	mei_read_slots(dev, dev->rd_msg_buf, discard_len);
 79	dev_dbg(&dev->dev, "discarding message " MEI_HDR_FMT "\n",
 80		MEI_HDR_PRM(hdr));
 81}
 82
 83/**
 84 * mei_cl_irq_read_msg - process client message
 85 *
 86 * @cl: reading client
 87 * @mei_hdr: header of mei client message
 88 * @meta: extend meta header
 89 * @cmpl_list: completion list
 90 *
 91 * Return: always 0
 92 */
 93static int mei_cl_irq_read_msg(struct mei_cl *cl,
 94			       struct mei_msg_hdr *mei_hdr,
 95			       struct mei_ext_meta_hdr *meta,
 96			       struct list_head *cmpl_list)
 97{
 98	struct mei_device *dev = cl->dev;
 99	struct mei_cl_cb *cb;
100
101	struct mei_ext_hdr_vtag *vtag_hdr = NULL;
102	struct mei_ext_hdr_gsc_f2h *gsc_f2h = NULL;
103
104	size_t buf_sz;
105	u32 length;
106	u32 ext_len;
107
108	length = mei_hdr->length;
109	ext_len = 0;
110	if (mei_hdr->extended) {
111		ext_len = sizeof(*meta) + mei_slots2data(meta->size);
112		length -= ext_len;
113	}
114
115	cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
116	if (!cb) {
117		if (!mei_cl_is_fixed_address(cl)) {
118			cl_err(dev, cl, "pending read cb not found\n");
119			goto discard;
120		}
121		cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
122		if (!cb)
123			goto discard;
124		list_add_tail(&cb->list, &cl->rd_pending);
125	}
126
127	if (mei_hdr->extended) {
128		struct mei_ext_hdr *ext = mei_ext_begin(meta);
129		do {
130			switch (ext->type) {
131			case MEI_EXT_HDR_VTAG:
132				vtag_hdr = (struct mei_ext_hdr_vtag *)ext;
133				break;
134			case MEI_EXT_HDR_GSC:
135				gsc_f2h = (struct mei_ext_hdr_gsc_f2h *)ext;
136				cb->ext_hdr = (struct mei_ext_hdr *)kzalloc(sizeof(*gsc_f2h), GFP_KERNEL);
137				if (!cb->ext_hdr) {
138					cb->status = -ENOMEM;
139					goto discard;
140				}
141				break;
142			case MEI_EXT_HDR_NONE:
143				fallthrough;
144			default:
145				cl_err(dev, cl, "unknown extended header\n");
146				cb->status = -EPROTO;
147				break;
148			}
149
150			ext = mei_ext_next(ext);
151		} while (!mei_ext_last(meta, ext));
152
153		if (!vtag_hdr && !gsc_f2h) {
154			cl_dbg(dev, cl, "no vtag or gsc found in extended header.\n");
155			cb->status = -EPROTO;
156			goto discard;
157		}
158	}
159
160	if (vtag_hdr) {
161		cl_dbg(dev, cl, "vtag: %d\n", vtag_hdr->vtag);
162		if (cb->vtag && cb->vtag != vtag_hdr->vtag) {
163			cl_err(dev, cl, "mismatched tag: %d != %d\n",
164			       cb->vtag, vtag_hdr->vtag);
165			cb->status = -EPROTO;
166			goto discard;
167		}
168		cb->vtag = vtag_hdr->vtag;
169	}
170
171	if (gsc_f2h) {
172		u32 ext_hdr_len = mei_ext_hdr_len(&gsc_f2h->hdr);
173
174		if (!dev->hbm_f_gsc_supported) {
175			cl_err(dev, cl, "gsc extended header is not supported\n");
176			cb->status = -EPROTO;
177			goto discard;
178		}
179
180		if (length) {
181			cl_err(dev, cl, "no data allowed in cb with gsc\n");
182			cb->status = -EPROTO;
183			goto discard;
184		}
185		if (ext_hdr_len > sizeof(*gsc_f2h)) {
186			cl_err(dev, cl, "gsc extended header is too big %u\n", ext_hdr_len);
187			cb->status = -EPROTO;
188			goto discard;
189		}
190		memcpy(cb->ext_hdr, gsc_f2h, ext_hdr_len);
191	}
192
193	if (!mei_cl_is_connected(cl)) {
194		cl_dbg(dev, cl, "not connected\n");
195		cb->status = -ENODEV;
196		goto discard;
197	}
198
199	if (mei_hdr->dma_ring)
200		length = mei_hdr->extension[mei_data2slots(ext_len)];
201
202	buf_sz = length + cb->buf_idx;
203	/* catch for integer overflow */
204	if (buf_sz < cb->buf_idx) {
205		cl_err(dev, cl, "message is too big len %d idx %zu\n",
206		       length, cb->buf_idx);
207		cb->status = -EMSGSIZE;
208		goto discard;
209	}
210
211	if (cb->buf.size < buf_sz) {
212		cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
213			cb->buf.size, length, cb->buf_idx);
214		cb->status = -EMSGSIZE;
215		goto discard;
216	}
217
218	if (mei_hdr->dma_ring) {
219		mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
220		/*  for DMA read 0 length to generate interrupt to the device */
221		mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0);
222	} else {
223		mei_read_slots(dev, cb->buf.data + cb->buf_idx, length);
224	}
225
226	cb->buf_idx += length;
227
228	if (mei_hdr->msg_complete) {
229		cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
230		list_move_tail(&cb->list, cmpl_list);
231	} else {
232		pm_request_autosuspend(dev->parent);
233	}
234
235	return 0;
236
237discard:
238	if (cb)
239		list_move_tail(&cb->list, cmpl_list);
240	mei_irq_discard_msg(dev, mei_hdr, length);
241	return 0;
242}
243
244/**
245 * mei_cl_irq_disconnect_rsp - send disconnection response message
246 *
247 * @cl: client
248 * @cb: callback block.
249 * @cmpl_list: complete list.
250 *
251 * Return: 0, OK; otherwise, error.
252 */
253static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
254				     struct list_head *cmpl_list)
255{
256	struct mei_device *dev = cl->dev;
257	u32 msg_slots;
258	int slots;
259	int ret;
260
261	msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
262	slots = mei_hbuf_empty_slots(dev);
263	if (slots < 0)
264		return -EOVERFLOW;
265
266	if ((u32)slots < msg_slots)
267		return -EMSGSIZE;
268
269	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
270	list_move_tail(&cb->list, cmpl_list);
271
272	return ret;
273}
274
275/**
276 * mei_cl_irq_read - processes client read related operation from the
277 *	interrupt thread context - request for flow control credits
278 *
279 * @cl: client
280 * @cb: callback block.
281 * @cmpl_list: complete list.
282 *
283 * Return: 0, OK; otherwise, error.
284 */
285static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
286			   struct list_head *cmpl_list)
287{
288	struct mei_device *dev = cl->dev;
289	u32 msg_slots;
290	int slots;
291	int ret;
292
293	if (!list_empty(&cl->rd_pending))
294		return 0;
295
296	msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
297	slots = mei_hbuf_empty_slots(dev);
298	if (slots < 0)
299		return -EOVERFLOW;
300
301	if ((u32)slots < msg_slots)
302		return -EMSGSIZE;
303
304	ret = mei_hbm_cl_flow_control_req(dev, cl);
305	if (ret) {
306		cl->status = ret;
307		cb->buf_idx = 0;
308		list_move_tail(&cb->list, cmpl_list);
309		return ret;
310	}
311
312	pm_request_autosuspend(dev->parent);
313
314	list_move_tail(&cb->list, &cl->rd_pending);
315
316	return 0;
317}
318
319static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
320{
321	return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
322}
323
324static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
325{
326	return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
327}
328
329static inline int hdr_is_valid(u32 msg_hdr)
330{
331	struct mei_msg_hdr *mei_hdr;
332	u32 expected_len = 0;
333
334	mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
335	if (!msg_hdr || mei_hdr->reserved)
336		return -EBADMSG;
337
338	if (mei_hdr->dma_ring)
339		expected_len += MEI_SLOT_SIZE;
340	if (mei_hdr->extended)
341		expected_len += MEI_SLOT_SIZE;
342	if (mei_hdr->length < expected_len)
343		return -EBADMSG;
344
345	return 0;
346}
347
348/**
349 * mei_irq_read_handler - bottom half read routine after ISR to
350 * handle the read processing.
351 *
352 * @dev: the device structure
353 * @cmpl_list: An instance of our list structure
354 * @slots: slots to read.
355 *
356 * Return: 0 on success, <0 on failure.
357 */
358int mei_irq_read_handler(struct mei_device *dev,
359			 struct list_head *cmpl_list, s32 *slots)
360{
361	struct mei_msg_hdr *mei_hdr;
362	struct mei_ext_meta_hdr *meta_hdr = NULL;
363	struct mei_cl *cl;
364	int ret;
365	u32 hdr_size_left;
366	u32 hdr_size_ext;
367	int i;
368	int ext_hdr_end;
369
370	if (!dev->rd_msg_hdr[0]) {
371		dev->rd_msg_hdr[0] = mei_read_hdr(dev);
372		dev->rd_msg_hdr_count = 1;
373		(*slots)--;
374		dev_dbg(&dev->dev, "slots =%08x.\n", *slots);
375
376		ret = hdr_is_valid(dev->rd_msg_hdr[0]);
377		if (ret) {
378			dev_err(&dev->dev, "corrupted message header 0x%08X\n",
379				dev->rd_msg_hdr[0]);
380			goto end;
381		}
382	}
383
384	mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
385	dev_dbg(&dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
386
387	if (mei_slots2data(*slots) < mei_hdr->length) {
388		dev_err(&dev->dev, "less data available than length=%08x.\n",
389				*slots);
390		/* we can't read the message */
391		ret = -ENODATA;
392		goto end;
393	}
394
395	ext_hdr_end = 1;
396	hdr_size_left = mei_hdr->length;
397
398	if (mei_hdr->extended) {
399		if (!dev->rd_msg_hdr[1]) {
400			dev->rd_msg_hdr[1] = mei_read_hdr(dev);
401			dev->rd_msg_hdr_count++;
402			(*slots)--;
403			dev_dbg(&dev->dev, "extended header is %08x\n", dev->rd_msg_hdr[1]);
404		}
405		meta_hdr = ((struct mei_ext_meta_hdr *)&dev->rd_msg_hdr[1]);
406		if (check_add_overflow((u32)sizeof(*meta_hdr),
407				       mei_slots2data(meta_hdr->size),
408				       &hdr_size_ext)) {
409			dev_err(&dev->dev, "extended message size too big %d\n",
410				meta_hdr->size);
411			return -EBADMSG;
412		}
413		if (hdr_size_left < hdr_size_ext) {
414			dev_err(&dev->dev, "corrupted message header len %d\n",
415				mei_hdr->length);
416			return -EBADMSG;
417		}
418		hdr_size_left -= hdr_size_ext;
419
420		ext_hdr_end = meta_hdr->size + 2;
421		for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
422			dev->rd_msg_hdr[i] = mei_read_hdr(dev);
423			dev_dbg(&dev->dev, "extended header %d is %08x\n", i,
424				dev->rd_msg_hdr[i]);
425			dev->rd_msg_hdr_count++;
426			(*slots)--;
427		}
428	}
429
430	if (mei_hdr->dma_ring) {
431		if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
432			dev_err(&dev->dev, "corrupted message header len %d\n",
433				mei_hdr->length);
434			return -EBADMSG;
435		}
436
437		dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
438		dev->rd_msg_hdr_count++;
439		(*slots)--;
440		mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
441	}
442
443	/*  HBM message */
444	if (hdr_is_hbm(mei_hdr)) {
445		ret = mei_hbm_dispatch(dev, mei_hdr);
446		if (ret) {
447			dev_dbg(&dev->dev, "mei_hbm_dispatch failed ret = %d\n", ret);
448			goto end;
449		}
450		goto reset_slots;
451	}
452
453	/* find recipient cl */
454	list_for_each_entry(cl, &dev->file_list, link) {
455		if (mei_cl_hbm_equal(cl, mei_hdr)) {
456			cl_dbg(dev, cl, "got a message\n");
457			ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
458			goto reset_slots;
459		}
460	}
461
462	/* if no recipient cl was found we assume corrupted header */
463	/* A message for not connected fixed address clients
464	 * should be silently discarded
465	 * On power down client may be force cleaned,
466	 * silently discard such messages
467	 */
468	if (hdr_is_fixed(mei_hdr) ||
469	    dev->dev_state == MEI_DEV_POWER_DOWN) {
470		mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
471		ret = 0;
472		goto reset_slots;
473	}
474	dev_err(&dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]);
475	ret = -EBADMSG;
476	goto end;
477
478reset_slots:
479	/* reset the number of slots and header */
480	memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
481	dev->rd_msg_hdr_count = 0;
482	*slots = mei_count_full_read_slots(dev);
483	if (*slots == -EOVERFLOW) {
484		/* overflow - reset */
485		dev_err(&dev->dev, "resetting due to slots overflow.\n");
486		/* set the event since message has been read */
487		ret = -ERANGE;
488		goto end;
489	}
490end:
491	return ret;
492}
493EXPORT_SYMBOL_GPL(mei_irq_read_handler);
494
495
496/**
497 * mei_irq_write_handler -  dispatch write requests
498 *  after irq received
499 *
500 * @dev: the device structure
501 * @cmpl_list: An instance of our list structure
502 *
503 * Return: 0 on success, <0 on failure.
504 */
505int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
506{
507
508	struct mei_cl *cl;
509	struct mei_cl_cb *cb, *next;
510	s32 slots;
511	int ret;
512
513
514	if (!mei_hbuf_acquire(dev))
515		return 0;
516
517	slots = mei_hbuf_empty_slots(dev);
518	if (slots < 0)
519		return -EOVERFLOW;
520
521	if (slots == 0)
522		return -EMSGSIZE;
523
524	/* complete all waiting for write CB */
525	dev_dbg(&dev->dev, "complete all waiting for write cb.\n");
526
527	list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
528		cl = cb->cl;
529
530		cl->status = 0;
531		cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
532		cl->writing_state = MEI_WRITE_COMPLETE;
533		list_move_tail(&cb->list, cmpl_list);
534	}
535
536	/* complete control write list CB */
537	dev_dbg(&dev->dev, "complete control write list cb.\n");
538	list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
539		cl = cb->cl;
540		switch (cb->fop_type) {
541		case MEI_FOP_DISCONNECT:
542			/* send disconnect message */
543			ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
544			if (ret)
545				return ret;
546
547			break;
548		case MEI_FOP_READ:
549			/* send flow control message */
550			ret = mei_cl_irq_read(cl, cb, cmpl_list);
551			if (ret)
552				return ret;
553
554			break;
555		case MEI_FOP_CONNECT:
556			/* connect message */
557			ret = mei_cl_irq_connect(cl, cb, cmpl_list);
558			if (ret)
559				return ret;
560
561			break;
562		case MEI_FOP_DISCONNECT_RSP:
563			/* send disconnect resp */
564			ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
565			if (ret)
566				return ret;
567			break;
568
569		case MEI_FOP_NOTIFY_START:
570		case MEI_FOP_NOTIFY_STOP:
571			ret = mei_cl_irq_notify(cl, cb, cmpl_list);
572			if (ret)
573				return ret;
574			break;
575		case MEI_FOP_DMA_MAP:
576			ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
577			if (ret)
578				return ret;
579			break;
580		case MEI_FOP_DMA_UNMAP:
581			ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
582			if (ret)
583				return ret;
584			break;
585		default:
586			BUG();
587		}
588
589	}
590	/* complete  write list CB */
591	dev_dbg(&dev->dev, "complete write list cb.\n");
592	list_for_each_entry_safe(cb, next, &dev->write_list, list) {
593		cl = cb->cl;
594		ret = mei_cl_irq_write(cl, cb, cmpl_list);
595		if (ret)
596			return ret;
597	}
598	return 0;
599}
600EXPORT_SYMBOL_GPL(mei_irq_write_handler);
601
602
603/**
604 * mei_connect_timeout  - connect/disconnect timeouts
605 *
606 * @cl: host client
607 */
608static void mei_connect_timeout(struct mei_cl *cl)
609{
610	struct mei_device *dev = cl->dev;
611
612	if (cl->state == MEI_FILE_CONNECTING) {
613		if (dev->hbm_f_dot_supported) {
614			cl->state = MEI_FILE_DISCONNECT_REQUIRED;
615			wake_up(&cl->wait);
616			return;
617		}
618	}
619	mei_reset(dev);
620}
621
622#define MEI_STALL_TIMER_FREQ (2 * HZ)
623/**
624 * mei_schedule_stall_timer - re-arm stall_timer work
625 *
626 * @dev: the device structure
627 *
628 * Schedule stall timer
629 */
630void mei_schedule_stall_timer(struct mei_device *dev)
631{
632	schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
633}
634
635/**
636 * mei_timer - timer function.
637 *
638 * @work: pointer to the work_struct structure
639 *
640 */
641void mei_timer(struct work_struct *work)
642{
643	struct mei_cl *cl;
644	struct mei_device *dev = container_of(work,
645					struct mei_device, timer_work.work);
646	bool reschedule_timer = false;
647
648	mutex_lock(&dev->device_lock);
649
650	/* Catch interrupt stalls during HBM init handshake */
651	if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
652	    dev->hbm_state != MEI_HBM_IDLE) {
653
654		if (dev->init_clients_timer) {
655			if (--dev->init_clients_timer == 0) {
656				dev_err(&dev->dev, "timer: init clients timeout hbm_state = %d.\n",
657					dev->hbm_state);
658				mei_reset(dev);
659				goto out;
660			}
661			reschedule_timer = true;
662		}
663	}
664
665	if (dev->dev_state != MEI_DEV_ENABLED)
666		goto out;
667
668	/*** connect/disconnect timeouts ***/
669	list_for_each_entry(cl, &dev->file_list, link) {
670		if (cl->timer_count) {
671			if (--cl->timer_count == 0) {
672				dev_err(&dev->dev, "timer: connect/disconnect timeout.\n");
673				mei_connect_timeout(cl);
674				goto out;
675			}
676			reschedule_timer = true;
677		}
678	}
679
680out:
681	if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
682		mei_schedule_stall_timer(dev);
683
684	mutex_unlock(&dev->device_lock);
685}