1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2003-2018, Intel Corporation. All rights reserved.
4 * Intel Management Engine Interface (Intel MEI) Linux driver
7 #include <linux/export.h>
8 #include <linux/kthread.h>
9 #include <linux/interrupt.h>
11 #include <linux/jiffies.h>
12 #include <linux/slab.h>
13 #include <linux/pm_runtime.h>
15 #include <linux/mei.h>
23 * mei_irq_compl_handler - dispatch complete handlers
24 * for the completed callbacks
27 * @cmpl_list: list of completed cbs
29 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
31 struct mei_cl_cb *cb, *next;
34 list_for_each_entry_safe(cb, next, cmpl_list, list) {
36 list_del_init(&cb->list);
38 dev_dbg(dev->dev, "completing call back.\n");
39 mei_cl_complete(cl, cb);
42 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
45 * mei_cl_hbm_equal - check if hbm is addressed to the client
48 * @mei_hdr: header of mei client message
50 * Return: true if matches, false otherwise
52 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
53 struct mei_msg_hdr *mei_hdr)
55 return mei_cl_host_addr(cl) == mei_hdr->host_addr &&
56 mei_cl_me_id(cl) == mei_hdr->me_addr;
60 * mei_irq_discard_msg - discard received message
63 * @hdr: message header
64 * @discard_len: the length of the message to discard (excluding header)
66 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr,
70 mei_dma_ring_read(dev, NULL,
71 hdr->extension[dev->rd_msg_hdr_count - 2]);
75 * no need to check for size as it is guarantied
76 * that length fits into rd_msg_buf
78 mei_read_slots(dev, dev->rd_msg_buf, discard_len);
79 dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
84 * mei_cl_irq_read_msg - process client message
87 * @mei_hdr: header of mei client message
88 * @meta: extend meta header
89 * @cmpl_list: completion list
93 static 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)
98 struct mei_device *dev = cl->dev;
105 length = mei_hdr->length;
107 if (mei_hdr->extended) {
108 ext_len = sizeof(*meta) + mei_slots2data(meta->size);
112 cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
114 if (!mei_cl_is_fixed_address(cl)) {
115 cl_err(dev, cl, "pending read cb not found\n");
118 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
121 list_add_tail(&cb->list, &cl->rd_pending);
124 if (mei_hdr->extended) {
125 struct mei_ext_hdr *ext;
126 struct mei_ext_hdr_vtag *vtag_hdr = NULL;
128 ext = mei_ext_begin(meta);
131 case MEI_EXT_HDR_VTAG:
132 vtag_hdr = (struct mei_ext_hdr_vtag *)ext;
134 case MEI_EXT_HDR_NONE:
137 cb->status = -EPROTO;
141 ext = mei_ext_next(ext);
142 } while (!mei_ext_last(meta, ext));
145 cl_dbg(dev, cl, "vtag not found in extended header.\n");
146 cb->status = -EPROTO;
150 cl_dbg(dev, cl, "vtag: %d\n", vtag_hdr->vtag);
151 if (cb->vtag && cb->vtag != vtag_hdr->vtag) {
152 cl_err(dev, cl, "mismatched tag: %d != %d\n",
153 cb->vtag, vtag_hdr->vtag);
154 cb->status = -EPROTO;
157 cb->vtag = vtag_hdr->vtag;
160 if (!mei_cl_is_connected(cl)) {
161 cl_dbg(dev, cl, "not connected\n");
162 cb->status = -ENODEV;
166 if (mei_hdr->dma_ring)
167 length = mei_hdr->extension[mei_data2slots(ext_len)];
169 buf_sz = length + cb->buf_idx;
170 /* catch for integer overflow */
171 if (buf_sz < cb->buf_idx) {
172 cl_err(dev, cl, "message is too big len %d idx %zu\n",
173 length, cb->buf_idx);
174 cb->status = -EMSGSIZE;
178 if (cb->buf.size < buf_sz) {
179 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
180 cb->buf.size, length, cb->buf_idx);
181 cb->status = -EMSGSIZE;
185 if (mei_hdr->dma_ring) {
186 mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
187 /* for DMA read 0 length to generate interrupt to the device */
188 mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0);
190 mei_read_slots(dev, cb->buf.data + cb->buf_idx, length);
193 cb->buf_idx += length;
195 if (mei_hdr->msg_complete) {
196 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
197 list_move_tail(&cb->list, cmpl_list);
199 pm_runtime_mark_last_busy(dev->dev);
200 pm_request_autosuspend(dev->dev);
207 list_move_tail(&cb->list, cmpl_list);
208 mei_irq_discard_msg(dev, mei_hdr, length);
213 * mei_cl_irq_disconnect_rsp - send disconnection response message
216 * @cb: callback block.
217 * @cmpl_list: complete list.
219 * Return: 0, OK; otherwise, error.
221 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
222 struct list_head *cmpl_list)
224 struct mei_device *dev = cl->dev;
229 msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
230 slots = mei_hbuf_empty_slots(dev);
234 if ((u32)slots < msg_slots)
237 ret = mei_hbm_cl_disconnect_rsp(dev, cl);
238 list_move_tail(&cb->list, cmpl_list);
244 * mei_cl_irq_read - processes client read related operation from the
245 * interrupt thread context - request for flow control credits
248 * @cb: callback block.
249 * @cmpl_list: complete list.
251 * Return: 0, OK; otherwise, error.
253 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
254 struct list_head *cmpl_list)
256 struct mei_device *dev = cl->dev;
261 if (!list_empty(&cl->rd_pending))
264 msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
265 slots = mei_hbuf_empty_slots(dev);
269 if ((u32)slots < msg_slots)
272 ret = mei_hbm_cl_flow_control_req(dev, cl);
276 list_move_tail(&cb->list, cmpl_list);
280 pm_runtime_mark_last_busy(dev->dev);
281 pm_request_autosuspend(dev->dev);
283 list_move_tail(&cb->list, &cl->rd_pending);
288 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
290 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
293 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
295 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
298 static inline int hdr_is_valid(u32 msg_hdr)
300 struct mei_msg_hdr *mei_hdr;
301 u32 expected_len = 0;
303 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
304 if (!msg_hdr || mei_hdr->reserved)
307 if (mei_hdr->dma_ring)
308 expected_len += MEI_SLOT_SIZE;
309 if (mei_hdr->extended)
310 expected_len += MEI_SLOT_SIZE;
311 if (mei_hdr->length < expected_len)
318 * mei_irq_read_handler - bottom half read routine after ISR to
319 * handle the read processing.
321 * @dev: the device structure
322 * @cmpl_list: An instance of our list structure
323 * @slots: slots to read.
325 * Return: 0 on success, <0 on failure.
327 int mei_irq_read_handler(struct mei_device *dev,
328 struct list_head *cmpl_list, s32 *slots)
330 struct mei_msg_hdr *mei_hdr;
331 struct mei_ext_meta_hdr *meta_hdr = NULL;
339 if (!dev->rd_msg_hdr[0]) {
340 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
341 dev->rd_msg_hdr_count = 1;
343 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
345 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
347 dev_err(dev->dev, "corrupted message header 0x%08X\n",
353 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
354 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
356 if (mei_slots2data(*slots) < mei_hdr->length) {
357 dev_err(dev->dev, "less data available than length=%08x.\n",
359 /* we can't read the message */
365 hdr_size_left = mei_hdr->length;
367 if (mei_hdr->extended) {
368 if (!dev->rd_msg_hdr[1]) {
369 dev->rd_msg_hdr[1] = mei_read_hdr(dev);
370 dev->rd_msg_hdr_count++;
372 dev_dbg(dev->dev, "extended header is %08x\n", dev->rd_msg_hdr[1]);
374 meta_hdr = ((struct mei_ext_meta_hdr *)&dev->rd_msg_hdr[1]);
375 if (check_add_overflow((u32)sizeof(*meta_hdr),
376 mei_slots2data(meta_hdr->size),
378 dev_err(dev->dev, "extended message size too big %d\n",
382 if (hdr_size_left < hdr_size_ext) {
383 dev_err(dev->dev, "corrupted message header len %d\n",
387 hdr_size_left -= hdr_size_ext;
389 ext_hdr_end = meta_hdr->size + 2;
390 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
391 dev->rd_msg_hdr[i] = mei_read_hdr(dev);
392 dev_dbg(dev->dev, "extended header %d is %08x\n", i,
394 dev->rd_msg_hdr_count++;
399 if (mei_hdr->dma_ring) {
400 if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
401 dev_err(dev->dev, "corrupted message header len %d\n",
406 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
407 dev->rd_msg_hdr_count++;
409 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
413 if (hdr_is_hbm(mei_hdr)) {
414 ret = mei_hbm_dispatch(dev, mei_hdr);
416 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
423 /* find recipient cl */
424 list_for_each_entry(cl, &dev->file_list, link) {
425 if (mei_cl_hbm_equal(cl, mei_hdr)) {
426 cl_dbg(dev, cl, "got a message\n");
427 ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
432 /* if no recipient cl was found we assume corrupted header */
433 /* A message for not connected fixed address clients
434 * should be silently discarded
435 * On power down client may be force cleaned,
436 * silently discard such messages
438 if (hdr_is_fixed(mei_hdr) ||
439 dev->dev_state == MEI_DEV_POWER_DOWN) {
440 mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
444 dev_err(dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]);
449 /* reset the number of slots and header */
450 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
451 dev->rd_msg_hdr_count = 0;
452 *slots = mei_count_full_read_slots(dev);
453 if (*slots == -EOVERFLOW) {
454 /* overflow - reset */
455 dev_err(dev->dev, "resetting due to slots overflow.\n");
456 /* set the event since message has been read */
463 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
467 * mei_irq_write_handler - dispatch write requests
470 * @dev: the device structure
471 * @cmpl_list: An instance of our list structure
473 * Return: 0 on success, <0 on failure.
475 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
479 struct mei_cl_cb *cb, *next;
484 if (!mei_hbuf_acquire(dev))
487 slots = mei_hbuf_empty_slots(dev);
494 /* complete all waiting for write CB */
495 dev_dbg(dev->dev, "complete all waiting for write cb.\n");
497 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
501 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
502 cl->writing_state = MEI_WRITE_COMPLETE;
503 list_move_tail(&cb->list, cmpl_list);
506 /* complete control write list CB */
507 dev_dbg(dev->dev, "complete control write list cb.\n");
508 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
510 switch (cb->fop_type) {
511 case MEI_FOP_DISCONNECT:
512 /* send disconnect message */
513 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
519 /* send flow control message */
520 ret = mei_cl_irq_read(cl, cb, cmpl_list);
525 case MEI_FOP_CONNECT:
526 /* connect message */
527 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
532 case MEI_FOP_DISCONNECT_RSP:
533 /* send disconnect resp */
534 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
539 case MEI_FOP_NOTIFY_START:
540 case MEI_FOP_NOTIFY_STOP:
541 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
545 case MEI_FOP_DMA_MAP:
546 ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
550 case MEI_FOP_DMA_UNMAP:
551 ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
560 /* complete write list CB */
561 dev_dbg(dev->dev, "complete write list cb.\n");
562 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
564 ret = mei_cl_irq_write(cl, cb, cmpl_list);
570 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
574 * mei_connect_timeout - connect/disconnect timeouts
578 static void mei_connect_timeout(struct mei_cl *cl)
580 struct mei_device *dev = cl->dev;
582 if (cl->state == MEI_FILE_CONNECTING) {
583 if (dev->hbm_f_dot_supported) {
584 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
592 #define MEI_STALL_TIMER_FREQ (2 * HZ)
594 * mei_schedule_stall_timer - re-arm stall_timer work
596 * Schedule stall timer
598 * @dev: the device structure
600 void mei_schedule_stall_timer(struct mei_device *dev)
602 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
606 * mei_timer - timer function.
608 * @work: pointer to the work_struct structure
611 void mei_timer(struct work_struct *work)
614 struct mei_device *dev = container_of(work,
615 struct mei_device, timer_work.work);
616 bool reschedule_timer = false;
618 mutex_lock(&dev->device_lock);
620 /* Catch interrupt stalls during HBM init handshake */
621 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
622 dev->hbm_state != MEI_HBM_IDLE) {
624 if (dev->init_clients_timer) {
625 if (--dev->init_clients_timer == 0) {
626 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
631 reschedule_timer = true;
635 if (dev->dev_state != MEI_DEV_ENABLED)
638 /*** connect/disconnect timeouts ***/
639 list_for_each_entry(cl, &dev->file_list, link) {
640 if (cl->timer_count) {
641 if (--cl->timer_count == 0) {
642 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
643 mei_connect_timeout(cl);
646 reschedule_timer = true;
651 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
652 mei_schedule_stall_timer(dev);
654 mutex_unlock(&dev->device_lock);