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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Management-Controller-to-Driver Interface
  4 *
  5 * Copyright 2008-2013 Solarflare Communications Inc.
  6 * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
  7 */
  8#include <linux/delay.h>
  9#include <linux/slab.h>
 10#include <linux/io.h>
 11#include <linux/spinlock.h>
 12#include <linux/netdevice.h>
 13#include <linux/etherdevice.h>
 14#include <linux/ethtool.h>
 15#include <linux/if_vlan.h>
 16#include <linux/timer.h>
 17#include <linux/list.h>
 18#include <linux/pci.h>
 19#include <linux/device.h>
 20#include <linux/rwsem.h>
 21#include <linux/vmalloc.h>
 22#include <net/netevent.h>
 23#include <linux/log2.h>
 24#include <linux/net_tstamp.h>
 25#include <linux/wait.h>
 26
 27#include "bitfield.h"
 28#include "mcdi.h"
 29
 30static void cdx_mcdi_cancel_cmd(struct cdx_mcdi *cdx, struct cdx_mcdi_cmd *cmd);
 31static void cdx_mcdi_wait_for_cleanup(struct cdx_mcdi *cdx);
 32static int cdx_mcdi_rpc_async_internal(struct cdx_mcdi *cdx,
 33				       struct cdx_mcdi_cmd *cmd,
 34				       unsigned int *handle);
 35static void cdx_mcdi_start_or_queue(struct cdx_mcdi_iface *mcdi,
 36				    bool allow_retry);
 37static void cdx_mcdi_cmd_start_or_queue(struct cdx_mcdi_iface *mcdi,
 38					struct cdx_mcdi_cmd *cmd);
 39static bool cdx_mcdi_complete_cmd(struct cdx_mcdi_iface *mcdi,
 40				  struct cdx_mcdi_cmd *cmd,
 41				  struct cdx_dword *outbuf,
 42				  int len,
 43				  struct list_head *cleanup_list);
 44static void cdx_mcdi_timeout_cmd(struct cdx_mcdi_iface *mcdi,
 45				 struct cdx_mcdi_cmd *cmd,
 46				 struct list_head *cleanup_list);
 47static void cdx_mcdi_cmd_work(struct work_struct *context);
 48static void cdx_mcdi_mode_fail(struct cdx_mcdi *cdx, struct list_head *cleanup_list);
 49static void _cdx_mcdi_display_error(struct cdx_mcdi *cdx, unsigned int cmd,
 50				    size_t inlen, int raw, int arg, int err_no);
 51
 52static bool cdx_cmd_cancelled(struct cdx_mcdi_cmd *cmd)
 53{
 54	return cmd->state == MCDI_STATE_RUNNING_CANCELLED;
 55}
 56
 57static void cdx_mcdi_cmd_release(struct kref *ref)
 58{
 59	kfree(container_of(ref, struct cdx_mcdi_cmd, ref));
 60}
 61
 62static unsigned int cdx_mcdi_cmd_handle(struct cdx_mcdi_cmd *cmd)
 63{
 64	return cmd->handle;
 65}
 66
 67static void _cdx_mcdi_remove_cmd(struct cdx_mcdi_iface *mcdi,
 68				 struct cdx_mcdi_cmd *cmd,
 69				 struct list_head *cleanup_list)
 70{
 71	/* if cancelled, the completers have already been called */
 72	if (cdx_cmd_cancelled(cmd))
 73		return;
 74
 75	if (cmd->completer) {
 76		list_add_tail(&cmd->cleanup_list, cleanup_list);
 77		++mcdi->outstanding_cleanups;
 78		kref_get(&cmd->ref);
 79	}
 80}
 81
 82static void cdx_mcdi_remove_cmd(struct cdx_mcdi_iface *mcdi,
 83				struct cdx_mcdi_cmd *cmd,
 84				struct list_head *cleanup_list)
 85{
 86	list_del(&cmd->list);
 87	_cdx_mcdi_remove_cmd(mcdi, cmd, cleanup_list);
 88	cmd->state = MCDI_STATE_FINISHED;
 89	kref_put(&cmd->ref, cdx_mcdi_cmd_release);
 90	if (list_empty(&mcdi->cmd_list))
 91		wake_up(&mcdi->cmd_complete_wq);
 92}
 93
 94static unsigned long cdx_mcdi_rpc_timeout(struct cdx_mcdi *cdx, unsigned int cmd)
 95{
 96	if (!cdx->mcdi_ops->mcdi_rpc_timeout)
 97		return MCDI_RPC_TIMEOUT;
 98	else
 99		return cdx->mcdi_ops->mcdi_rpc_timeout(cdx, cmd);
100}
101
102int cdx_mcdi_init(struct cdx_mcdi *cdx)
103{
104	struct cdx_mcdi_iface *mcdi;
105	int rc = -ENOMEM;
106
107	cdx->mcdi = kzalloc(sizeof(*cdx->mcdi), GFP_KERNEL);
108	if (!cdx->mcdi)
109		goto fail;
110
111	mcdi = cdx_mcdi_if(cdx);
112	mcdi->cdx = cdx;
113
114	mcdi->workqueue = alloc_ordered_workqueue("mcdi_wq", 0);
115	if (!mcdi->workqueue)
116		goto fail2;
117	mutex_init(&mcdi->iface_lock);
118	mcdi->mode = MCDI_MODE_EVENTS;
119	INIT_LIST_HEAD(&mcdi->cmd_list);
120	init_waitqueue_head(&mcdi->cmd_complete_wq);
121
122	mcdi->new_epoch = true;
123
124	return 0;
125fail2:
126	kfree(cdx->mcdi);
127	cdx->mcdi = NULL;
128fail:
129	return rc;
130}
131
132void cdx_mcdi_finish(struct cdx_mcdi *cdx)
133{
134	struct cdx_mcdi_iface *mcdi;
135
136	mcdi = cdx_mcdi_if(cdx);
137	if (!mcdi)
138		return;
139
140	cdx_mcdi_wait_for_cleanup(cdx);
141
142	destroy_workqueue(mcdi->workqueue);
143	kfree(cdx->mcdi);
144	cdx->mcdi = NULL;
145}
146
147static bool cdx_mcdi_flushed(struct cdx_mcdi_iface *mcdi, bool ignore_cleanups)
148{
149	bool flushed;
150
151	mutex_lock(&mcdi->iface_lock);
152	flushed = list_empty(&mcdi->cmd_list) &&
153		  (ignore_cleanups || !mcdi->outstanding_cleanups);
154	mutex_unlock(&mcdi->iface_lock);
155	return flushed;
156}
157
158/* Wait for outstanding MCDI commands to complete. */
159static void cdx_mcdi_wait_for_cleanup(struct cdx_mcdi *cdx)
160{
161	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
162
163	if (!mcdi)
164		return;
165
166	wait_event(mcdi->cmd_complete_wq,
167		   cdx_mcdi_flushed(mcdi, false));
168}
169
170int cdx_mcdi_wait_for_quiescence(struct cdx_mcdi *cdx,
171				 unsigned int timeout_jiffies)
172{
173	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
174	DEFINE_WAIT_FUNC(wait, woken_wake_function);
175	int rc = 0;
176
177	if (!mcdi)
178		return -EINVAL;
179
180	flush_workqueue(mcdi->workqueue);
181
182	add_wait_queue(&mcdi->cmd_complete_wq, &wait);
183
184	while (!cdx_mcdi_flushed(mcdi, true)) {
185		rc = wait_woken(&wait, TASK_IDLE, timeout_jiffies);
186		if (rc)
187			continue;
188		break;
189	}
190
191	remove_wait_queue(&mcdi->cmd_complete_wq, &wait);
192
193	if (rc > 0)
194		rc = 0;
195	else if (rc == 0)
196		rc = -ETIMEDOUT;
197
198	return rc;
199}
200
201static u8 cdx_mcdi_payload_csum(const struct cdx_dword *hdr, size_t hdr_len,
202				const struct cdx_dword *sdu, size_t sdu_len)
203{
204	u8 *p = (u8 *)hdr;
205	u8 csum = 0;
206	int i;
207
208	for (i = 0; i < hdr_len; i++)
209		csum += p[i];
210
211	p = (u8 *)sdu;
212	for (i = 0; i < sdu_len; i++)
213		csum += p[i];
214
215	return ~csum & 0xff;
216}
217
218static void cdx_mcdi_send_request(struct cdx_mcdi *cdx,
219				  struct cdx_mcdi_cmd *cmd)
220{
221	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
222	const struct cdx_dword *inbuf = cmd->inbuf;
223	size_t inlen = cmd->inlen;
224	struct cdx_dword hdr[2];
225	size_t hdr_len;
226	bool not_epoch;
227	u32 xflags;
228
229	if (!mcdi)
230		return;
231
232	mcdi->prev_seq = cmd->seq;
233	mcdi->seq_held_by[cmd->seq] = cmd;
234	mcdi->db_held_by = cmd;
235	cmd->started = jiffies;
236
237	not_epoch = !mcdi->new_epoch;
238	xflags = 0;
239
240	/* MCDI v2 */
241	WARN_ON(inlen > MCDI_CTL_SDU_LEN_MAX_V2);
242	CDX_POPULATE_DWORD_7(hdr[0],
243			     MCDI_HEADER_RESPONSE, 0,
244			     MCDI_HEADER_RESYNC, 1,
245			     MCDI_HEADER_CODE, MC_CMD_V2_EXTN,
246			     MCDI_HEADER_DATALEN, 0,
247			     MCDI_HEADER_SEQ, cmd->seq,
248			     MCDI_HEADER_XFLAGS, xflags,
249			     MCDI_HEADER_NOT_EPOCH, not_epoch);
250	CDX_POPULATE_DWORD_3(hdr[1],
251			     MC_CMD_V2_EXTN_IN_EXTENDED_CMD, cmd->cmd,
252			     MC_CMD_V2_EXTN_IN_ACTUAL_LEN, inlen,
253			     MC_CMD_V2_EXTN_IN_MESSAGE_TYPE,
254			     MC_CMD_V2_EXTN_IN_MCDI_MESSAGE_TYPE_PLATFORM);
255	hdr_len = 8;
256
257	hdr[0].cdx_u32 |= (__force __le32)(cdx_mcdi_payload_csum(hdr, hdr_len, inbuf, inlen) <<
258			 MCDI_HEADER_XFLAGS_LBN);
259
260	print_hex_dump_debug("MCDI REQ HEADER: ", DUMP_PREFIX_NONE, 32, 4, hdr, hdr_len, false);
261	print_hex_dump_debug("MCDI REQ PAYLOAD: ", DUMP_PREFIX_NONE, 32, 4, inbuf, inlen, false);
262
263	cdx->mcdi_ops->mcdi_request(cdx, hdr, hdr_len, inbuf, inlen);
264
265	mcdi->new_epoch = false;
266}
267
268static int cdx_mcdi_errno(struct cdx_mcdi *cdx, unsigned int mcdi_err)
269{
270	switch (mcdi_err) {
271	case 0:
272	case MC_CMD_ERR_QUEUE_FULL:
273		return mcdi_err;
274	case MC_CMD_ERR_EPERM:
275		return -EPERM;
276	case MC_CMD_ERR_ENOENT:
277		return -ENOENT;
278	case MC_CMD_ERR_EINTR:
279		return -EINTR;
280	case MC_CMD_ERR_EAGAIN:
281		return -EAGAIN;
282	case MC_CMD_ERR_EACCES:
283		return -EACCES;
284	case MC_CMD_ERR_EBUSY:
285		return -EBUSY;
286	case MC_CMD_ERR_EINVAL:
287		return -EINVAL;
288	case MC_CMD_ERR_ERANGE:
289		return -ERANGE;
290	case MC_CMD_ERR_EDEADLK:
291		return -EDEADLK;
292	case MC_CMD_ERR_ENOSYS:
293		return -EOPNOTSUPP;
294	case MC_CMD_ERR_ETIME:
295		return -ETIME;
296	case MC_CMD_ERR_EALREADY:
297		return -EALREADY;
298	case MC_CMD_ERR_ENOSPC:
299		return -ENOSPC;
300	case MC_CMD_ERR_ENOMEM:
301		return -ENOMEM;
302	case MC_CMD_ERR_ENOTSUP:
303		return -EOPNOTSUPP;
304	case MC_CMD_ERR_ALLOC_FAIL:
305		return -ENOBUFS;
306	case MC_CMD_ERR_MAC_EXIST:
307		return -EADDRINUSE;
308	case MC_CMD_ERR_NO_EVB_PORT:
309		return -EAGAIN;
310	default:
311		return -EPROTO;
312	}
313}
314
315static void cdx_mcdi_process_cleanup_list(struct cdx_mcdi *cdx,
316					  struct list_head *cleanup_list)
317{
318	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
319	unsigned int cleanups = 0;
320
321	if (!mcdi)
322		return;
323
324	while (!list_empty(cleanup_list)) {
325		struct cdx_mcdi_cmd *cmd =
326			list_first_entry(cleanup_list,
327					 struct cdx_mcdi_cmd, cleanup_list);
328		cmd->completer(cdx, cmd->cookie, cmd->rc,
329			       cmd->outbuf, cmd->outlen);
330		list_del(&cmd->cleanup_list);
331		kref_put(&cmd->ref, cdx_mcdi_cmd_release);
332		++cleanups;
333	}
334
335	if (cleanups) {
336		bool all_done;
337
338		mutex_lock(&mcdi->iface_lock);
339		CDX_WARN_ON_PARANOID(cleanups > mcdi->outstanding_cleanups);
340		all_done = (mcdi->outstanding_cleanups -= cleanups) == 0;
341		mutex_unlock(&mcdi->iface_lock);
342		if (all_done)
343			wake_up(&mcdi->cmd_complete_wq);
344	}
345}
346
347static void _cdx_mcdi_cancel_cmd(struct cdx_mcdi_iface *mcdi,
348				 unsigned int handle,
349				 struct list_head *cleanup_list)
350{
351	struct cdx_mcdi_cmd *cmd;
352
353	list_for_each_entry(cmd, &mcdi->cmd_list, list)
354		if (cdx_mcdi_cmd_handle(cmd) == handle) {
355			switch (cmd->state) {
356			case MCDI_STATE_QUEUED:
357			case MCDI_STATE_RETRY:
358				pr_debug("command %#x inlen %zu cancelled in queue\n",
359					 cmd->cmd, cmd->inlen);
360				/* if not yet running, properly cancel it */
361				cmd->rc = -EPIPE;
362				cdx_mcdi_remove_cmd(mcdi, cmd, cleanup_list);
363				break;
364			case MCDI_STATE_RUNNING:
365			case MCDI_STATE_RUNNING_CANCELLED:
366			case MCDI_STATE_FINISHED:
367			default:
368				/* invalid state? */
369				WARN_ON(1);
370			}
371			break;
372		}
373}
374
375static void cdx_mcdi_cancel_cmd(struct cdx_mcdi *cdx, struct cdx_mcdi_cmd *cmd)
376{
377	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
378	LIST_HEAD(cleanup_list);
379
380	if (!mcdi)
381		return;
382
383	mutex_lock(&mcdi->iface_lock);
384	cdx_mcdi_timeout_cmd(mcdi, cmd, &cleanup_list);
385	mutex_unlock(&mcdi->iface_lock);
386	cdx_mcdi_process_cleanup_list(cdx, &cleanup_list);
387}
388
389struct cdx_mcdi_blocking_data {
390	struct kref ref;
391	bool done;
392	wait_queue_head_t wq;
393	int rc;
394	struct cdx_dword *outbuf;
395	size_t outlen;
396	size_t outlen_actual;
397};
398
399static void cdx_mcdi_blocking_data_release(struct kref *ref)
400{
401	kfree(container_of(ref, struct cdx_mcdi_blocking_data, ref));
402}
403
404static void cdx_mcdi_rpc_completer(struct cdx_mcdi *cdx, unsigned long cookie,
405				   int rc, struct cdx_dword *outbuf,
406				   size_t outlen_actual)
407{
408	struct cdx_mcdi_blocking_data *wait_data =
409		(struct cdx_mcdi_blocking_data *)cookie;
410
411	wait_data->rc = rc;
412	memcpy(wait_data->outbuf, outbuf,
413	       min(outlen_actual, wait_data->outlen));
414	wait_data->outlen_actual = outlen_actual;
415	/* memory barrier */
416	smp_wmb();
417	wait_data->done = true;
418	wake_up(&wait_data->wq);
419	kref_put(&wait_data->ref, cdx_mcdi_blocking_data_release);
420}
421
422static int cdx_mcdi_rpc_sync(struct cdx_mcdi *cdx, unsigned int cmd,
423			     const struct cdx_dword *inbuf, size_t inlen,
424			     struct cdx_dword *outbuf, size_t outlen,
425			     size_t *outlen_actual, bool quiet)
426{
427	struct cdx_mcdi_blocking_data *wait_data;
428	struct cdx_mcdi_cmd *cmd_item;
429	unsigned int handle;
430	int rc;
431
432	if (outlen_actual)
433		*outlen_actual = 0;
434
435	wait_data = kmalloc(sizeof(*wait_data), GFP_KERNEL);
436	if (!wait_data)
437		return -ENOMEM;
438
439	cmd_item = kmalloc(sizeof(*cmd_item), GFP_KERNEL);
440	if (!cmd_item) {
441		kfree(wait_data);
442		return -ENOMEM;
443	}
444
445	kref_init(&wait_data->ref);
446	wait_data->done = false;
447	init_waitqueue_head(&wait_data->wq);
448	wait_data->outbuf = outbuf;
449	wait_data->outlen = outlen;
450
451	kref_init(&cmd_item->ref);
452	cmd_item->quiet = quiet;
453	cmd_item->cookie = (unsigned long)wait_data;
454	cmd_item->completer = &cdx_mcdi_rpc_completer;
455	cmd_item->cmd = cmd;
456	cmd_item->inlen = inlen;
457	cmd_item->inbuf = inbuf;
458
459	/* Claim an extra reference for the completer to put. */
460	kref_get(&wait_data->ref);
461	rc = cdx_mcdi_rpc_async_internal(cdx, cmd_item, &handle);
462	if (rc) {
463		kref_put(&wait_data->ref, cdx_mcdi_blocking_data_release);
464		goto out;
465	}
466
467	if (!wait_event_timeout(wait_data->wq, wait_data->done,
468				cdx_mcdi_rpc_timeout(cdx, cmd)) &&
469	    !wait_data->done) {
470		pr_err("MC command 0x%x inlen %zu timed out (sync)\n",
471		       cmd, inlen);
472
473		cdx_mcdi_cancel_cmd(cdx, cmd_item);
474
475		wait_data->rc = -ETIMEDOUT;
476		wait_data->outlen_actual = 0;
477	}
478
479	if (outlen_actual)
480		*outlen_actual = wait_data->outlen_actual;
481	rc = wait_data->rc;
482
483out:
484	kref_put(&wait_data->ref, cdx_mcdi_blocking_data_release);
485
486	return rc;
487}
488
489static bool cdx_mcdi_get_seq(struct cdx_mcdi_iface *mcdi, unsigned char *seq)
490{
491	*seq = mcdi->prev_seq;
492	do {
493		*seq = (*seq + 1) % ARRAY_SIZE(mcdi->seq_held_by);
494	} while (mcdi->seq_held_by[*seq] && *seq != mcdi->prev_seq);
495	return !mcdi->seq_held_by[*seq];
496}
497
498static int cdx_mcdi_rpc_async_internal(struct cdx_mcdi *cdx,
499				       struct cdx_mcdi_cmd *cmd,
500				       unsigned int *handle)
501{
502	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
503	LIST_HEAD(cleanup_list);
504
505	if (!mcdi) {
506		kref_put(&cmd->ref, cdx_mcdi_cmd_release);
507		return -ENETDOWN;
508	}
509
510	if (mcdi->mode == MCDI_MODE_FAIL) {
511		kref_put(&cmd->ref, cdx_mcdi_cmd_release);
512		return -ENETDOWN;
513	}
514
515	cmd->mcdi = mcdi;
516	INIT_WORK(&cmd->work, cdx_mcdi_cmd_work);
517	INIT_LIST_HEAD(&cmd->list);
518	INIT_LIST_HEAD(&cmd->cleanup_list);
519	cmd->rc = 0;
520	cmd->outbuf = NULL;
521	cmd->outlen = 0;
522
523	queue_work(mcdi->workqueue, &cmd->work);
524	return 0;
525}
526
527static void cdx_mcdi_cmd_start_or_queue(struct cdx_mcdi_iface *mcdi,
528					struct cdx_mcdi_cmd *cmd)
529{
530	struct cdx_mcdi *cdx = mcdi->cdx;
531	u8 seq;
532
533	if (!mcdi->db_held_by &&
534	    cdx_mcdi_get_seq(mcdi, &seq)) {
535		cmd->seq = seq;
536		cmd->reboot_seen = false;
537		cdx_mcdi_send_request(cdx, cmd);
538		cmd->state = MCDI_STATE_RUNNING;
539	} else {
540		cmd->state = MCDI_STATE_QUEUED;
541	}
542}
543
544/* try to advance other commands */
545static void cdx_mcdi_start_or_queue(struct cdx_mcdi_iface *mcdi,
546				    bool allow_retry)
547{
548	struct cdx_mcdi_cmd *cmd, *tmp;
549
550	list_for_each_entry_safe(cmd, tmp, &mcdi->cmd_list, list)
551		if (cmd->state == MCDI_STATE_QUEUED ||
552		    (cmd->state == MCDI_STATE_RETRY && allow_retry))
553			cdx_mcdi_cmd_start_or_queue(mcdi, cmd);
554}
555
556void cdx_mcdi_process_cmd(struct cdx_mcdi *cdx, struct cdx_dword *outbuf, int len)
557{
558	struct cdx_mcdi_iface *mcdi;
559	struct cdx_mcdi_cmd *cmd;
560	LIST_HEAD(cleanup_list);
561	unsigned int respseq;
562
563	if (!len || !outbuf) {
564		pr_err("Got empty MC response\n");
565		return;
566	}
567
568	mcdi = cdx_mcdi_if(cdx);
569	if (!mcdi)
570		return;
571
572	respseq = CDX_DWORD_FIELD(outbuf[0], MCDI_HEADER_SEQ);
573
574	mutex_lock(&mcdi->iface_lock);
575	cmd = mcdi->seq_held_by[respseq];
576
577	if (cmd) {
578		if (cmd->state == MCDI_STATE_FINISHED) {
579			mutex_unlock(&mcdi->iface_lock);
580			kref_put(&cmd->ref, cdx_mcdi_cmd_release);
581			return;
582		}
583
584		cdx_mcdi_complete_cmd(mcdi, cmd, outbuf, len, &cleanup_list);
585	} else {
586		pr_err("MC response unexpected for seq : %0X\n", respseq);
587	}
588
589	mutex_unlock(&mcdi->iface_lock);
590
591	cdx_mcdi_process_cleanup_list(mcdi->cdx, &cleanup_list);
592}
593
594static void cdx_mcdi_cmd_work(struct work_struct *context)
595{
596	struct cdx_mcdi_cmd *cmd =
597		container_of(context, struct cdx_mcdi_cmd, work);
598	struct cdx_mcdi_iface *mcdi = cmd->mcdi;
599
600	mutex_lock(&mcdi->iface_lock);
601
602	cmd->handle = mcdi->prev_handle++;
603	list_add_tail(&cmd->list, &mcdi->cmd_list);
604	cdx_mcdi_cmd_start_or_queue(mcdi, cmd);
605
606	mutex_unlock(&mcdi->iface_lock);
607}
608
609/*
610 * Returns true if the MCDI module is finished with the command.
611 * (examples of false would be if the command was proxied, or it was
612 * rejected by the MC due to lack of resources and requeued).
613 */
614static bool cdx_mcdi_complete_cmd(struct cdx_mcdi_iface *mcdi,
615				  struct cdx_mcdi_cmd *cmd,
616				  struct cdx_dword *outbuf,
617				  int len,
618				  struct list_head *cleanup_list)
619{
620	size_t resp_hdr_len, resp_data_len;
621	struct cdx_mcdi *cdx = mcdi->cdx;
622	unsigned int respcmd, error;
623	bool completed = false;
624	int rc;
625
626	/* ensure the command can't go away before this function returns */
627	kref_get(&cmd->ref);
628
629	respcmd = CDX_DWORD_FIELD(outbuf[0], MCDI_HEADER_CODE);
630	error = CDX_DWORD_FIELD(outbuf[0], MCDI_HEADER_ERROR);
631
632	if (respcmd != MC_CMD_V2_EXTN) {
633		resp_hdr_len = 4;
634		resp_data_len = CDX_DWORD_FIELD(outbuf[0], MCDI_HEADER_DATALEN);
635	} else {
636		resp_data_len = 0;
637		resp_hdr_len = 8;
638		if (len >= 8)
639			resp_data_len =
640				CDX_DWORD_FIELD(outbuf[1], MC_CMD_V2_EXTN_IN_ACTUAL_LEN);
641	}
642
643	if ((resp_hdr_len + resp_data_len) > len) {
644		pr_warn("Incomplete MCDI response received %d. Expected %zu\n",
645			len, (resp_hdr_len + resp_data_len));
646		resp_data_len = 0;
647	}
648
649	print_hex_dump_debug("MCDI RESP HEADER: ", DUMP_PREFIX_NONE, 32, 4,
650			     outbuf, resp_hdr_len, false);
651	print_hex_dump_debug("MCDI RESP PAYLOAD: ", DUMP_PREFIX_NONE, 32, 4,
652			     outbuf + (resp_hdr_len / 4), resp_data_len, false);
653
654	if (error && resp_data_len == 0) {
655		/* MC rebooted during command */
656		rc = -EIO;
657	} else {
658		if (WARN_ON_ONCE(error && resp_data_len < 4))
659			resp_data_len = 4;
660		if (error) {
661			rc = CDX_DWORD_FIELD(outbuf[resp_hdr_len / 4], CDX_DWORD);
662			if (!cmd->quiet) {
663				int err_arg = 0;
664
665				if (resp_data_len >= MC_CMD_ERR_ARG_OFST + 4) {
666					int offset = (resp_hdr_len + MC_CMD_ERR_ARG_OFST) / 4;
667
668					err_arg = CDX_DWORD_VAL(outbuf[offset]);
669				}
670
671				_cdx_mcdi_display_error(cdx, cmd->cmd,
672							cmd->inlen, rc, err_arg,
673							cdx_mcdi_errno(cdx, rc));
674			}
675			rc = cdx_mcdi_errno(cdx, rc);
676		} else {
677			rc = 0;
678		}
679	}
680
681	/* free doorbell */
682	if (mcdi->db_held_by == cmd)
683		mcdi->db_held_by = NULL;
684
685	if (cdx_cmd_cancelled(cmd)) {
686		list_del(&cmd->list);
687		kref_put(&cmd->ref, cdx_mcdi_cmd_release);
688		completed = true;
689	} else if (rc == MC_CMD_ERR_QUEUE_FULL) {
690		cmd->state = MCDI_STATE_RETRY;
691	} else {
692		cmd->rc = rc;
693		cmd->outbuf = outbuf + DIV_ROUND_UP(resp_hdr_len, 4);
694		cmd->outlen = resp_data_len;
695		cdx_mcdi_remove_cmd(mcdi, cmd, cleanup_list);
696		completed = true;
697	}
698
699	/* free sequence number and buffer */
700	mcdi->seq_held_by[cmd->seq] = NULL;
701
702	cdx_mcdi_start_or_queue(mcdi, rc != MC_CMD_ERR_QUEUE_FULL);
703
704	/* wake up anyone waiting for flush */
705	wake_up(&mcdi->cmd_complete_wq);
706
707	kref_put(&cmd->ref, cdx_mcdi_cmd_release);
708
709	return completed;
710}
711
712static void cdx_mcdi_timeout_cmd(struct cdx_mcdi_iface *mcdi,
713				 struct cdx_mcdi_cmd *cmd,
714				 struct list_head *cleanup_list)
715{
716	struct cdx_mcdi *cdx = mcdi->cdx;
717
718	pr_err("MC command 0x%x inlen %zu state %d timed out after %u ms\n",
719	       cmd->cmd, cmd->inlen, cmd->state,
720	       jiffies_to_msecs(jiffies - cmd->started));
721
722	cmd->rc = -ETIMEDOUT;
723	cdx_mcdi_remove_cmd(mcdi, cmd, cleanup_list);
724
725	cdx_mcdi_mode_fail(cdx, cleanup_list);
726}
727
728/**
729 * cdx_mcdi_rpc - Issue an MCDI command and wait for completion
730 * @cdx: NIC through which to issue the command
731 * @cmd: Command type number
732 * @inbuf: Command parameters
733 * @inlen: Length of command parameters, in bytes. Must be a multiple
734 *	of 4 and no greater than %MCDI_CTL_SDU_LEN_MAX_V1.
735 * @outbuf: Response buffer. May be %NULL if @outlen is 0.
736 * @outlen: Length of response buffer, in bytes. If the actual
737 *	response is longer than @outlen & ~3, it will be truncated
738 *	to that length.
739 * @outlen_actual: Pointer through which to return the actual response
740 *	length. May be %NULL if this is not needed.
741 *
742 * This function may sleep and therefore must be called in process
743 * context.
744 *
745 * Return: A negative error code, or zero if successful. The error
746 *	code may come from the MCDI response or may indicate a failure
747 *	to communicate with the MC. In the former case, the response
748 *	will still be copied to @outbuf and *@outlen_actual will be
749 *	set accordingly. In the latter case, *@outlen_actual will be
750 *	set to zero.
751 */
752int cdx_mcdi_rpc(struct cdx_mcdi *cdx, unsigned int cmd,
753		 const struct cdx_dword *inbuf, size_t inlen,
754		 struct cdx_dword *outbuf, size_t outlen,
755		 size_t *outlen_actual)
756{
757	return cdx_mcdi_rpc_sync(cdx, cmd, inbuf, inlen, outbuf, outlen,
758				 outlen_actual, false);
759}
760
761/**
762 * cdx_mcdi_rpc_async - Schedule an MCDI command to run asynchronously
763 * @cdx: NIC through which to issue the command
764 * @cmd: Command type number
765 * @inbuf: Command parameters
766 * @inlen: Length of command parameters, in bytes
767 * @complete: Function to be called on completion or cancellation.
768 * @cookie: Arbitrary value to be passed to @complete.
769 *
770 * This function does not sleep and therefore may be called in atomic
771 * context.  It will fail if event queues are disabled or if MCDI
772 * event completions have been disabled due to an error.
773 *
774 * If it succeeds, the @complete function will be called exactly once
775 * in process context, when one of the following occurs:
776 * (a) the completion event is received (in process context)
777 * (b) event queues are disabled (in the process that disables them)
778 */
779int
780cdx_mcdi_rpc_async(struct cdx_mcdi *cdx, unsigned int cmd,
781		   const struct cdx_dword *inbuf, size_t inlen,
782		   cdx_mcdi_async_completer *complete, unsigned long cookie)
783{
784	struct cdx_mcdi_cmd *cmd_item =
785		kmalloc(sizeof(struct cdx_mcdi_cmd) + inlen, GFP_ATOMIC);
786
787	if (!cmd_item)
788		return -ENOMEM;
789
790	kref_init(&cmd_item->ref);
791	cmd_item->quiet = true;
792	cmd_item->cookie = cookie;
793	cmd_item->completer = complete;
794	cmd_item->cmd = cmd;
795	cmd_item->inlen = inlen;
796	/* inbuf is probably not valid after return, so take a copy */
797	cmd_item->inbuf = (struct cdx_dword *)(cmd_item + 1);
798	memcpy(cmd_item + 1, inbuf, inlen);
799
800	return cdx_mcdi_rpc_async_internal(cdx, cmd_item, NULL);
801}
802
803static void _cdx_mcdi_display_error(struct cdx_mcdi *cdx, unsigned int cmd,
804				    size_t inlen, int raw, int arg, int err_no)
805{
806	pr_err("MC command 0x%x inlen %d failed err_no=%d (raw=%d) arg=%d\n",
807	       cmd, (int)inlen, err_no, raw, arg);
808}
809
810/*
811 * Set MCDI mode to fail to prevent any new commands, then cancel any
812 * outstanding commands.
813 * Caller must hold the mcdi iface_lock.
814 */
815static void cdx_mcdi_mode_fail(struct cdx_mcdi *cdx, struct list_head *cleanup_list)
816{
817	struct cdx_mcdi_iface *mcdi = cdx_mcdi_if(cdx);
818
819	if (!mcdi)
820		return;
821
822	mcdi->mode = MCDI_MODE_FAIL;
823
824	while (!list_empty(&mcdi->cmd_list)) {
825		struct cdx_mcdi_cmd *cmd;
826
827		cmd = list_first_entry(&mcdi->cmd_list, struct cdx_mcdi_cmd,
828				       list);
829		_cdx_mcdi_cancel_cmd(mcdi, cdx_mcdi_cmd_handle(cmd), cleanup_list);
830	}
831}