1	// SPDX-License-Identifier: GPL-2.0+
2	/*
3	* ipmi_ssif.c
4	*
5	* The interface to the IPMI driver for SMBus access to a SMBus
6	* compliant device. Called SSIF by the IPMI spec.
7	*
8	* Author: Intel Corporation
9	* Todd Davis <todd.c.davis@intel.com>
10	*
11	* Rewritten by Corey Minyard <minyard@acm.org> to support the
12	* non-blocking I2C interface, add support for multi-part
13	* transactions, add PEC support, and general clenaup.
14	*
15	* Copyright 2003 Intel Corporation
16	* Copyright 2005 MontaVista Software
17	*/
18
19	/*
20	* This file holds the "policy" for the interface to the SSIF state
21	* machine. It does the configuration, handles timers and interrupts,
22	* and drives the real SSIF state machine.
23	*/
24
25	#define pr_fmt(fmt) "ipmi_ssif: " fmt
26	#define dev_fmt(fmt) "ipmi_ssif: " fmt
27
28	#if defined(MODVERSIONS)
29	#include <linux/modversions.h>
30	#endif
31
32	#include <linux/module.h>
33	#include <linux/moduleparam.h>
34	#include <linux/sched.h>
35	#include <linux/seq_file.h>
36	#include <linux/timer.h>
37	#include <linux/delay.h>
38	#include <linux/errno.h>
39	#include <linux/spinlock.h>
40	#include <linux/slab.h>
41	#include <linux/list.h>
42	#include <linux/i2c.h>
43	#include <linux/ipmi_smi.h>
44	#include <linux/init.h>
45	#include <linux/dmi.h>
46	#include <linux/kthread.h>
47	#include <linux/acpi.h>
48	#include <linux/ctype.h>
49	#include <linux/time64.h>
50	#include "ipmi_dmi.h"
51
52	#define DEVICE_NAME "ipmi_ssif"
53
54	#define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD 0x57
55
56	#define SSIF_IPMI_REQUEST 2
57	#define SSIF_IPMI_MULTI_PART_REQUEST_START 6
58	#define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE 7
59	#define SSIF_IPMI_MULTI_PART_REQUEST_END 8
60	#define SSIF_IPMI_RESPONSE 3
61	#define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE 9
62
63	/* ssif_debug is a bit-field
64	* SSIF_DEBUG_MSG - commands and their responses
65	* SSIF_DEBUG_STATES - message states
66	* SSIF_DEBUG_TIMING - Measure times between events in the driver
67	*/
68	#define SSIF_DEBUG_TIMING 4
69	#define SSIF_DEBUG_STATE 2
70	#define SSIF_DEBUG_MSG 1
71	#define SSIF_NODEBUG 0
72	#define SSIF_DEFAULT_DEBUG (SSIF_NODEBUG)
73
74	/*
75	* Timer values
76	*/
77	#define SSIF_MSG_USEC 60000 /* 60ms between message tries (T3). */
78	#define SSIF_REQ_RETRY_USEC 60000 /* 60ms between send retries (T6). */
79	#define SSIF_MSG_PART_USEC 5000 /* 5ms for a message part */
80
81	/* How many times to we retry sending/receiving the message. */
82	#define SSIF_SEND_RETRIES 5
83	#define SSIF_RECV_RETRIES 250
84
85	#define SSIF_MSG_MSEC (SSIF_MSG_USEC / 1000)
86	#define SSIF_REQ_RETRY_MSEC (SSIF_REQ_RETRY_USEC / 1000)
87	#define SSIF_MSG_JIFFIES ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
88	#define SSIF_REQ_RETRY_JIFFIES ((SSIF_REQ_RETRY_USEC * 1000) / TICK_NSEC)
89	#define SSIF_MSG_PART_JIFFIES ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
90
91	/*
92	* Timeout for the watch, only used for get flag timer.
93	*/
94	#define SSIF_WATCH_MSG_TIMEOUT msecs_to_jiffies(10)
95	#define SSIF_WATCH_WATCHDOG_TIMEOUT msecs_to_jiffies(250)
96
97	enum ssif_intf_state {
98	SSIF_IDLE,
99	SSIF_GETTING_FLAGS,
100	SSIF_GETTING_EVENTS,
101	SSIF_CLEARING_FLAGS,
102	SSIF_GETTING_MESSAGES,
103	/* FIXME - add watchdog stuff. */
104	};
105
106	#define IS_SSIF_IDLE(ssif) ((ssif)->ssif_state == SSIF_IDLE \
107	&& (ssif)->curr_msg == NULL)
108
109	/*
110	* Indexes into stats[] in ssif_info below.
111	*/
112	enum ssif_stat_indexes {
113	/* Number of total messages sent. */
114	SSIF_STAT_sent_messages = 0,
115
116	/*
117	* Number of message parts sent. Messages may be broken into
118	* parts if they are long.
119	*/
120	SSIF_STAT_sent_messages_parts,
121
122	/*
123	* Number of time a message was retried.
124	*/
125	SSIF_STAT_send_retries,
126
127	/*
128	* Number of times the send of a message failed.
129	*/
130	SSIF_STAT_send_errors,
131
132	/*
133	* Number of message responses received.
134	*/
135	SSIF_STAT_received_messages,
136
137	/*
138	* Number of message fragments received.
139	*/
140	SSIF_STAT_received_message_parts,
141
142	/*
143	* Number of times the receive of a message was retried.
144	*/
145	SSIF_STAT_receive_retries,
146
147	/*
148	* Number of errors receiving messages.
149	*/
150	SSIF_STAT_receive_errors,
151
152	/*
153	* Number of times a flag fetch was requested.
154	*/
155	SSIF_STAT_flag_fetches,
156
157	/*
158	* Number of times the hardware didn't follow the state machine.
159	*/
160	SSIF_STAT_hosed,
161
162	/*
163	* Number of received events.
164	*/
165	SSIF_STAT_events,
166
167	/* Number of asyncronous messages received. */
168	SSIF_STAT_incoming_messages,
169
170	/* Number of watchdog pretimeouts. */
171	SSIF_STAT_watchdog_pretimeouts,
172
173	/* Number of alers received. */
174	SSIF_STAT_alerts,
175
176	/* Always add statistics before this value, it must be last. */
177	SSIF_NUM_STATS
178	};
179
180	struct ssif_addr_info {
181	struct i2c_board_info binfo;
182	char *adapter_name;
183	int debug;
184	int slave_addr;
185	enum ipmi_addr_src addr_src;
186	union ipmi_smi_info_union addr_info;
187	struct device *dev;
188	struct i2c_client *client;
189
190	struct mutex clients_mutex;
191	struct list_head clients;
192
193	struct list_head link;
194	};
195
196	struct ssif_info;
197
198	typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
199	unsigned char *data, unsigned int len);
200
201	struct ssif_info {
202	struct ipmi_smi *intf;
203	spinlock_t lock;
204	struct ipmi_smi_msg *waiting_msg;
205	struct ipmi_smi_msg *curr_msg;
206	enum ssif_intf_state ssif_state;
207	unsigned long ssif_debug;
208
209	struct ipmi_smi_handlers handlers;
210
211	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
212	union ipmi_smi_info_union addr_info;
213
214	/*
215	* Flags from the last GET_MSG_FLAGS command, used when an ATTN
216	* is set to hold the flags until we are done handling everything
217	* from the flags.
218	*/
219	#define RECEIVE_MSG_AVAIL 0x01
220	#define EVENT_MSG_BUFFER_FULL 0x02
221	#define WDT_PRE_TIMEOUT_INT 0x08
222	unsigned char msg_flags;
223
224	u8 global_enables;
225	bool has_event_buffer;
226	bool supports_alert;
227
228	/*
229	* Used to tell what we should do with alerts. If we are
230	* waiting on a response, read the data immediately.
231	*/
232	bool got_alert;
233	bool waiting_alert;
234
235	/* Used to inform the timeout that it should do a resend. */
236	bool do_resend;
237
238	/*
239	* If set to true, this will request events the next time the
240	* state machine is idle.
241	*/
242	bool req_events;
243
244	/*
245	* If set to true, this will request flags the next time the
246	* state machine is idle.
247	*/
248	bool req_flags;
249
250	/* Used for sending/receiving data. +1 for the length. */
251	unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
252	unsigned int data_len;
253
254	/* Temp receive buffer, gets copied into data. */
255	unsigned char recv[I2C_SMBUS_BLOCK_MAX];
256
257	struct i2c_client *client;
258	ssif_i2c_done done_handler;
259
260	/* Thread interface handling */
261	struct task_struct *thread;
262	struct completion wake_thread;
263	bool stopping;
264	int i2c_read_write;
265	int i2c_command;
266	unsigned char *i2c_data;
267	unsigned int i2c_size;
268
269	struct timer_list retry_timer;
270	int retries_left;
271
272	long watch_timeout; /* Timeout for flags check, 0 if off. */
273	struct timer_list watch_timer; /* Flag fetch timer. */
274
275	/* Info from SSIF cmd */
276	unsigned char max_xmit_msg_size;
277	unsigned char max_recv_msg_size;
278	bool cmd8_works; /* See test_multipart_messages() for details. */
279	unsigned int multi_support;
280	int supports_pec;
281
282	#define SSIF_NO_MULTI 0
283	#define SSIF_MULTI_2_PART 1
284	#define SSIF_MULTI_n_PART 2
285	unsigned char *multi_data;
286	unsigned int multi_len;
287	unsigned int multi_pos;
288
289	atomic_t stats[SSIF_NUM_STATS];
290	};
291
292	#define ssif_inc_stat(ssif, stat) \
293	atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
294	#define ssif_get_stat(ssif, stat) \
295	((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
296
297	static bool initialized;
298	static bool platform_registered;
299
300	static void return_hosed_msg(struct ssif_info *ssif_info,
301	struct ipmi_smi_msg *msg);
302	static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
303	static int start_send(struct ssif_info *ssif_info,
304	unsigned char *data,
305	unsigned int len);
306
307	static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
308	unsigned long *flags)
309	__acquires(&ssif_info->lock)
310	{
311	spin_lock_irqsave(&ssif_info->lock, *flags);
312	return flags;
313	}
314
315	static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
316	unsigned long *flags)
317	__releases(&ssif_info->lock)
318	{
319	spin_unlock_irqrestore(lock: &ssif_info->lock, flags: *flags);
320	}
321
322	static void deliver_recv_msg(struct ssif_info *ssif_info,
323	struct ipmi_smi_msg *msg)
324	{
325	if (msg->rsp_size < 0) {
326	return_hosed_msg(ssif_info, msg);
327	dev_err(&ssif_info->client->dev,
328	"%s: Malformed message: rsp_size = %d\n",
329	__func__, msg->rsp_size);
330	} else {
331	ipmi_smi_msg_received(intf: ssif_info->intf, msg);
332	}
333	}
334
335	static void return_hosed_msg(struct ssif_info *ssif_info,
336	struct ipmi_smi_msg *msg)
337	{
338	ssif_inc_stat(ssif_info, hosed);
339
340	/* Make it a response */
341	msg->rsp[0] = msg->data[0] | 4;
342	msg->rsp[1] = msg->data[1];
343	msg->rsp[2] = 0xFF; /* Unknown error. */
344	msg->rsp_size = 3;
345
346	deliver_recv_msg(ssif_info, msg);
347	}
348
349	/*
350	* Must be called with the message lock held. This will release the
351	* message lock. Note that the caller will check IS_SSIF_IDLE and
352	* start a new operation, so there is no need to check for new
353	* messages to start in here.
354	*/
355	static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
356	{
357	unsigned char msg[3];
358
359	ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
360	ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
361	ipmi_ssif_unlock_cond(ssif_info, flags);
362
363	/* Make sure the watchdog pre-timeout flag is not set at startup. */
364	msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
365	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
366	msg[2] = WDT_PRE_TIMEOUT_INT;
367
368	if (start_send(ssif_info, data: msg, len: 3) != 0) {
369	/* Error, just go to normal state. */
370	ssif_info->ssif_state = SSIF_IDLE;
371	}
372	}
373
374	static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
375	{
376	unsigned char mb[2];
377
378	ssif_info->req_flags = false;
379	ssif_info->ssif_state = SSIF_GETTING_FLAGS;
380	ipmi_ssif_unlock_cond(ssif_info, flags);
381
382	mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
383	mb[1] = IPMI_GET_MSG_FLAGS_CMD;
384	if (start_send(ssif_info, data: mb, len: 2) != 0)
385	ssif_info->ssif_state = SSIF_IDLE;
386	}
387
388	static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
389	struct ipmi_smi_msg *msg)
390	{
391	if (start_send(ssif_info, data: msg->data, len: msg->data_size) != 0) {
392	unsigned long oflags;
393
394	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
395	ssif_info->curr_msg = NULL;
396	ssif_info->ssif_state = SSIF_IDLE;
397	ipmi_ssif_unlock_cond(ssif_info, flags);
398	ipmi_free_smi_msg(msg);
399	}
400	}
401
402	static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
403	{
404	struct ipmi_smi_msg *msg;
405
406	ssif_info->req_events = false;
407
408	msg = ipmi_alloc_smi_msg();
409	if (!msg) {
410	ssif_info->ssif_state = SSIF_IDLE;
411	ipmi_ssif_unlock_cond(ssif_info, flags);
412	return;
413	}
414
415	ssif_info->curr_msg = msg;
416	ssif_info->ssif_state = SSIF_GETTING_EVENTS;
417	ipmi_ssif_unlock_cond(ssif_info, flags);
418
419	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
420	msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
421	msg->data_size = 2;
422
423	check_start_send(ssif_info, flags, msg);
424	}
425
426	static void start_recv_msg_fetch(struct ssif_info *ssif_info,
427	unsigned long *flags)
428	{
429	struct ipmi_smi_msg *msg;
430
431	msg = ipmi_alloc_smi_msg();
432	if (!msg) {
433	ssif_info->ssif_state = SSIF_IDLE;
434	ipmi_ssif_unlock_cond(ssif_info, flags);
435	return;
436	}
437
438	ssif_info->curr_msg = msg;
439	ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
440	ipmi_ssif_unlock_cond(ssif_info, flags);
441
442	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
443	msg->data[1] = IPMI_GET_MSG_CMD;
444	msg->data_size = 2;
445
446	check_start_send(ssif_info, flags, msg);
447	}
448
449	/*
450	* Must be called with the message lock held. This will release the
451	* message lock. Note that the caller will check IS_SSIF_IDLE and
452	* start a new operation, so there is no need to check for new
453	* messages to start in here.
454	*/
455	static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
456	{
457	if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
458	/* Watchdog pre-timeout */
459	ssif_inc_stat(ssif_info, watchdog_pretimeouts);
460	start_clear_flags(ssif_info, flags);
461	ipmi_smi_watchdog_pretimeout(intf: ssif_info->intf);
462	} else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
463	/* Messages available. */
464	start_recv_msg_fetch(ssif_info, flags);
465	else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
466	/* Events available. */
467	start_event_fetch(ssif_info, flags);
468	else {
469	ssif_info->ssif_state = SSIF_IDLE;
470	ipmi_ssif_unlock_cond(ssif_info, flags);
471	}
472	}
473
474	static int ipmi_ssif_thread(void *data)
475	{
476	struct ssif_info *ssif_info = data;
477
478	while (!kthread_should_stop()) {
479	int result;
480
481	/* Wait for something to do */
482	result = wait_for_completion_interruptible(
483	x: &ssif_info->wake_thread);
484	if (ssif_info->stopping)
485	break;
486	if (result == -ERESTARTSYS)
487	continue;
488	init_completion(x: &ssif_info->wake_thread);
489
490	if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
491	result = i2c_smbus_write_block_data(
492	client: ssif_info->client, command: ssif_info->i2c_command,
493	length: ssif_info->i2c_data[0],
494	values: ssif_info->i2c_data + 1);
495	ssif_info->done_handler(ssif_info, result, NULL, 0);
496	} else {
497	result = i2c_smbus_read_block_data(
498	client: ssif_info->client, command: ssif_info->i2c_command,
499	values: ssif_info->i2c_data);
500	if (result < 0)
501	ssif_info->done_handler(ssif_info, result,
502	NULL, 0);
503	else
504	ssif_info->done_handler(ssif_info, 0,
505	ssif_info->i2c_data,
506	result);
507	}
508	}
509
510	return 0;
511	}
512
513	static void ssif_i2c_send(struct ssif_info *ssif_info,
514	ssif_i2c_done handler,
515	int read_write, int command,
516	unsigned char *data, unsigned int size)
517	{
518	ssif_info->done_handler = handler;
519
520	ssif_info->i2c_read_write = read_write;
521	ssif_info->i2c_command = command;
522	ssif_info->i2c_data = data;
523	ssif_info->i2c_size = size;
524	complete(&ssif_info->wake_thread);
525	}
526
527
528	static void msg_done_handler(struct ssif_info *ssif_info, int result,
529	unsigned char *data, unsigned int len);
530
531	static void start_get(struct ssif_info *ssif_info)
532	{
533	ssif_info->multi_pos = 0;
534
535	ssif_i2c_send(ssif_info, handler: msg_done_handler, I2C_SMBUS_READ,
536	SSIF_IPMI_RESPONSE,
537	data: ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
538	}
539
540	static void start_resend(struct ssif_info *ssif_info);
541
542	static void retry_timeout(struct timer_list *t)
543	{
544	struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
545	unsigned long oflags, *flags;
546	bool waiting, resend;
547
548	if (ssif_info->stopping)
549	return;
550
551	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
552	resend = ssif_info->do_resend;
553	ssif_info->do_resend = false;
554	waiting = ssif_info->waiting_alert;
555	ssif_info->waiting_alert = false;
556	ipmi_ssif_unlock_cond(ssif_info, flags);
557
558	if (waiting)
559	start_get(ssif_info);
560	if (resend) {
561	start_resend(ssif_info);
562	ssif_inc_stat(ssif_info, send_retries);
563	}
564	}
565
566	static void watch_timeout(struct timer_list *t)
567	{
568	struct ssif_info *ssif_info = from_timer(ssif_info, t, watch_timer);
569	unsigned long oflags, *flags;
570
571	if (ssif_info->stopping)
572	return;
573
574	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
575	if (ssif_info->watch_timeout) {
576	mod_timer(timer: &ssif_info->watch_timer,
577	expires: jiffies + ssif_info->watch_timeout);
578	if (IS_SSIF_IDLE(ssif_info)) {
579	start_flag_fetch(ssif_info, flags); /* Releases lock */
580	return;
581	}
582	ssif_info->req_flags = true;
583	}
584	ipmi_ssif_unlock_cond(ssif_info, flags);
585	}
586
587	static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
588	unsigned int data)
589	{
590	struct ssif_info *ssif_info = i2c_get_clientdata(client);
591	unsigned long oflags, *flags;
592	bool do_get = false;
593
594	if (type != I2C_PROTOCOL_SMBUS_ALERT)
595	return;
596
597	ssif_inc_stat(ssif_info, alerts);
598
599	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
600	if (ssif_info->waiting_alert) {
601	ssif_info->waiting_alert = false;
602	del_timer(timer: &ssif_info->retry_timer);
603	do_get = true;
604	} else if (ssif_info->curr_msg) {
605	ssif_info->got_alert = true;
606	}
607	ipmi_ssif_unlock_cond(ssif_info, flags);
608	if (do_get)
609	start_get(ssif_info);
610	}
611
612	static void msg_done_handler(struct ssif_info *ssif_info, int result,
613	unsigned char *data, unsigned int len)
614	{
615	struct ipmi_smi_msg *msg;
616	unsigned long oflags, *flags;
617
618	/*
619	* We are single-threaded here, so no need for a lock until we
620	* start messing with driver states or the queues.
621	*/
622
623	if (result < 0) {
624	ssif_info->retries_left--;
625	if (ssif_info->retries_left > 0) {
626	ssif_inc_stat(ssif_info, receive_retries);
627
628	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
629	ssif_info->waiting_alert = true;
630	if (!ssif_info->stopping)
631	mod_timer(timer: &ssif_info->retry_timer,
632	expires: jiffies + SSIF_MSG_JIFFIES);
633	ipmi_ssif_unlock_cond(ssif_info, flags);
634	return;
635	}
636
637	ssif_inc_stat(ssif_info, receive_errors);
638
639	if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
640	dev_dbg(&ssif_info->client->dev,
641	"%s: Error %d\n", __func__, result);
642	len = 0;
643	goto continue_op;
644	}
645
646	if ((len > 1) && (ssif_info->multi_pos == 0)
647	&& (data[0] == 0x00) && (data[1] == 0x01)) {
648	/* Start of multi-part read. Start the next transaction. */
649	int i;
650
651	ssif_inc_stat(ssif_info, received_message_parts);
652
653	/* Remove the multi-part read marker. */
654	len -= 2;
655	data += 2;
656	for (i = 0; i < len; i++)
657	ssif_info->data[i] = data[i];
658	ssif_info->multi_len = len;
659	ssif_info->multi_pos = 1;
660
661	ssif_i2c_send(ssif_info, handler: msg_done_handler, I2C_SMBUS_READ,
662	SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
663	data: ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
664	return;
665	} else if (ssif_info->multi_pos) {
666	/* Middle of multi-part read. Start the next transaction. */
667	int i;
668	unsigned char blocknum;
669
670	if (len == 0) {
671	result = -EIO;
672	if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
673	dev_dbg(&ssif_info->client->dev,
674	"Middle message with no data\n");
675
676	goto continue_op;
677	}
678
679	blocknum = data[0];
680	len--;
681	data++;
682
683	if (blocknum != 0xff && len != 31) {
684	/* All blocks but the last must have 31 data bytes. */
685	result = -EIO;
686	if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
687	dev_dbg(&ssif_info->client->dev,
688	"Received middle message <31\n");
689
690	goto continue_op;
691	}
692
693	if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
694	/* Received message too big, abort the operation. */
695	result = -E2BIG;
696	if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
697	dev_dbg(&ssif_info->client->dev,
698	"Received message too big\n");
699
700	goto continue_op;
701	}
702
703	for (i = 0; i < len; i++)
704	ssif_info->data[i + ssif_info->multi_len] = data[i];
705	ssif_info->multi_len += len;
706	if (blocknum == 0xff) {
707	/* End of read */
708	len = ssif_info->multi_len;
709	data = ssif_info->data;
710	} else if (blocknum + 1 != ssif_info->multi_pos) {
711	/*
712	* Out of sequence block, just abort. Block
713	* numbers start at zero for the second block,
714	* but multi_pos starts at one, so the +1.
715	*/
716	if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
717	dev_dbg(&ssif_info->client->dev,
718	"Received message out of sequence, expected %u, got %u\n",
719	ssif_info->multi_pos - 1, blocknum);
720	result = -EIO;
721	} else {
722	ssif_inc_stat(ssif_info, received_message_parts);
723
724	ssif_info->multi_pos++;
725
726	ssif_i2c_send(ssif_info, handler: msg_done_handler,
727	I2C_SMBUS_READ,
728	SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
729	data: ssif_info->recv,
730	I2C_SMBUS_BLOCK_DATA);
731	return;
732	}
733	}
734
735	continue_op:
736	if (result < 0) {
737	ssif_inc_stat(ssif_info, receive_errors);
738	} else {
739	ssif_inc_stat(ssif_info, received_messages);
740	ssif_inc_stat(ssif_info, received_message_parts);
741	}
742
743	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
744	dev_dbg(&ssif_info->client->dev,
745	"DONE 1: state = %d, result=%d\n",
746	ssif_info->ssif_state, result);
747
748	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
749	msg = ssif_info->curr_msg;
750	if (msg) {
751	if (data) {
752	if (len > IPMI_MAX_MSG_LENGTH)
753	len = IPMI_MAX_MSG_LENGTH;
754	memcpy(msg->rsp, data, len);
755	} else {
756	len = 0;
757	}
758	msg->rsp_size = len;
759	ssif_info->curr_msg = NULL;
760	}
761
762	switch (ssif_info->ssif_state) {
763	case SSIF_IDLE:
764	ipmi_ssif_unlock_cond(ssif_info, flags);
765	if (!msg)
766	break;
767
768	if (result < 0)
769	return_hosed_msg(ssif_info, msg);
770	else
771	deliver_recv_msg(ssif_info, msg);
772	break;
773
774	case SSIF_GETTING_FLAGS:
775	/* We got the flags from the SSIF, now handle them. */
776	if ((result < 0) || (len < 4) || (data[2] != 0)) {
777	/*
778	* Error fetching flags, or invalid length,
779	* just give up for now.
780	*/
781	ssif_info->ssif_state = SSIF_IDLE;
782	ipmi_ssif_unlock_cond(ssif_info, flags);
783	dev_warn(&ssif_info->client->dev,
784	"Error getting flags: %d %d, %x\n",
785	result, len, (len >= 3) ? data[2] : 0);
786	} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
787	|| data[1] != IPMI_GET_MSG_FLAGS_CMD) {
788	/*
789	* Recv error response, give up.
790	*/
791	ssif_info->ssif_state = SSIF_IDLE;
792	ipmi_ssif_unlock_cond(ssif_info, flags);
793	dev_warn(&ssif_info->client->dev,
794	"Invalid response getting flags: %x %x\n",
795	data[0], data[1]);
796	} else {
797	ssif_inc_stat(ssif_info, flag_fetches);
798	ssif_info->msg_flags = data[3];
799	handle_flags(ssif_info, flags);
800	}
801	break;
802
803	case SSIF_CLEARING_FLAGS:
804	/* We cleared the flags. */
805	if ((result < 0) || (len < 3) || (data[2] != 0)) {
806	/* Error clearing flags */
807	dev_warn(&ssif_info->client->dev,
808	"Error clearing flags: %d %d, %x\n",
809	result, len, (len >= 3) ? data[2] : 0);
810	} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
811	|| data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
812	dev_warn(&ssif_info->client->dev,
813	"Invalid response clearing flags: %x %x\n",
814	data[0], data[1]);
815	}
816	ssif_info->ssif_state = SSIF_IDLE;
817	ipmi_ssif_unlock_cond(ssif_info, flags);
818	break;
819
820	case SSIF_GETTING_EVENTS:
821	if (!msg) {
822	/* Should never happen, but just in case. */
823	dev_warn(&ssif_info->client->dev,
824	"No message set while getting events\n");
825	ipmi_ssif_unlock_cond(ssif_info, flags);
826	break;
827	}
828
829	if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
830	/* Error getting event, probably done. */
831	msg->done(msg);
832
833	/* Take off the event flag. */
834	ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
835	handle_flags(ssif_info, flags);
836	} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
837	|| msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
838	dev_warn(&ssif_info->client->dev,
839	"Invalid response getting events: %x %x\n",
840	msg->rsp[0], msg->rsp[1]);
841	msg->done(msg);
842	/* Take off the event flag. */
843	ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
844	handle_flags(ssif_info, flags);
845	} else {
846	handle_flags(ssif_info, flags);
847	ssif_inc_stat(ssif_info, events);
848	deliver_recv_msg(ssif_info, msg);
849	}
850	break;
851
852	case SSIF_GETTING_MESSAGES:
853	if (!msg) {
854	/* Should never happen, but just in case. */
855	dev_warn(&ssif_info->client->dev,
856	"No message set while getting messages\n");
857	ipmi_ssif_unlock_cond(ssif_info, flags);
858	break;
859	}
860
861	if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
862	/* Error getting event, probably done. */
863	msg->done(msg);
864
865	/* Take off the msg flag. */
866	ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
867	handle_flags(ssif_info, flags);
868	} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
869	|| msg->rsp[1] != IPMI_GET_MSG_CMD) {
870	dev_warn(&ssif_info->client->dev,
871	"Invalid response clearing flags: %x %x\n",
872	msg->rsp[0], msg->rsp[1]);
873	msg->done(msg);
874
875	/* Take off the msg flag. */
876	ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
877	handle_flags(ssif_info, flags);
878	} else {
879	ssif_inc_stat(ssif_info, incoming_messages);
880	handle_flags(ssif_info, flags);
881	deliver_recv_msg(ssif_info, msg);
882	}
883	break;
884
885	default:
886	/* Should never happen, but just in case. */
887	dev_warn(&ssif_info->client->dev,
888	"Invalid state in message done handling: %d\n",
889	ssif_info->ssif_state);
890	ipmi_ssif_unlock_cond(ssif_info, flags);
891	}
892
893	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
894	if (IS_SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
895	if (ssif_info->req_events)
896	start_event_fetch(ssif_info, flags);
897	else if (ssif_info->req_flags)
898	start_flag_fetch(ssif_info, flags);
899	else
900	start_next_msg(ssif_info, flags);
901	} else
902	ipmi_ssif_unlock_cond(ssif_info, flags);
903
904	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
905	dev_dbg(&ssif_info->client->dev,
906	"DONE 2: state = %d.\n", ssif_info->ssif_state);
907	}
908
909	static void msg_written_handler(struct ssif_info *ssif_info, int result,
910	unsigned char *data, unsigned int len)
911	{
912	/* We are single-threaded here, so no need for a lock. */
913	if (result < 0) {
914	ssif_info->retries_left--;
915	if (ssif_info->retries_left > 0) {
916	/*
917	* Wait the retry timeout time per the spec,
918	* then redo the send.
919	*/
920	ssif_info->do_resend = true;
921	mod_timer(timer: &ssif_info->retry_timer,
922	expires: jiffies + SSIF_REQ_RETRY_JIFFIES);
923	return;
924	}
925
926	ssif_inc_stat(ssif_info, send_errors);
927
928	if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
929	dev_dbg(&ssif_info->client->dev,
930	"%s: Out of retries\n", __func__);
931
932	msg_done_handler(ssif_info, result: -EIO, NULL, len: 0);
933	return;
934	}
935
936	if (ssif_info->multi_data) {
937	/*
938	* In the middle of a multi-data write. See the comment
939	* in the SSIF_MULTI_n_PART case in the probe function
940	* for details on the intricacies of this.
941	*/
942	int left, to_write;
943	unsigned char *data_to_send;
944	unsigned char cmd;
945
946	ssif_inc_stat(ssif_info, sent_messages_parts);
947
948	left = ssif_info->multi_len - ssif_info->multi_pos;
949	to_write = left;
950	if (to_write > 32)
951	to_write = 32;
952	/* Length byte. */
953	ssif_info->multi_data[ssif_info->multi_pos] = to_write;
954	data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
955	ssif_info->multi_pos += to_write;
956	cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
957	if (ssif_info->cmd8_works) {
958	if (left == to_write) {
959	cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
960	ssif_info->multi_data = NULL;
961	}
962	} else if (to_write < 32) {
963	ssif_info->multi_data = NULL;
964	}
965
966	ssif_i2c_send(ssif_info, handler: msg_written_handler,
967	I2C_SMBUS_WRITE, command: cmd,
968	data: data_to_send, I2C_SMBUS_BLOCK_DATA);
969	} else {
970	/* Ready to request the result. */
971	unsigned long oflags, *flags;
972
973	ssif_inc_stat(ssif_info, sent_messages);
974	ssif_inc_stat(ssif_info, sent_messages_parts);
975
976	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
977	if (ssif_info->got_alert) {
978	/* The result is already ready, just start it. */
979	ssif_info->got_alert = false;
980	ipmi_ssif_unlock_cond(ssif_info, flags);
981	start_get(ssif_info);
982	} else {
983	/* Wait a jiffie then request the next message */
984	ssif_info->waiting_alert = true;
985	ssif_info->retries_left = SSIF_RECV_RETRIES;
986	if (!ssif_info->stopping)
987	mod_timer(timer: &ssif_info->retry_timer,
988	expires: jiffies + SSIF_MSG_PART_JIFFIES);
989	ipmi_ssif_unlock_cond(ssif_info, flags);
990	}
991	}
992	}
993
994	static void start_resend(struct ssif_info *ssif_info)
995	{
996	int command;
997
998	ssif_info->got_alert = false;
999
1000	if (ssif_info->data_len > 32) {
1001	command = SSIF_IPMI_MULTI_PART_REQUEST_START;
1002	ssif_info->multi_data = ssif_info->data;
1003	ssif_info->multi_len = ssif_info->data_len;
1004	/*
1005	* Subtle thing, this is 32, not 33, because we will
1006	* overwrite the thing at position 32 (which was just
1007	* transmitted) with the new length.
1008	*/
1009	ssif_info->multi_pos = 32;
1010	ssif_info->data[0] = 32;
1011	} else {
1012	ssif_info->multi_data = NULL;
1013	command = SSIF_IPMI_REQUEST;
1014	ssif_info->data[0] = ssif_info->data_len;
1015	}
1016
1017	ssif_i2c_send(ssif_info, handler: msg_written_handler, I2C_SMBUS_WRITE,
1018	command, data: ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1019	}
1020
1021	static int start_send(struct ssif_info *ssif_info,
1022	unsigned char *data,
1023	unsigned int len)
1024	{
1025	if (len > IPMI_MAX_MSG_LENGTH)
1026	return -E2BIG;
1027	if (len > ssif_info->max_xmit_msg_size)
1028	return -E2BIG;
1029
1030	ssif_info->retries_left = SSIF_SEND_RETRIES;
1031	memcpy(ssif_info->data + 1, data, len);
1032	ssif_info->data_len = len;
1033	start_resend(ssif_info);
1034	return 0;
1035	}
1036
1037	/* Must be called with the message lock held. */
1038	static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1039	{
1040	struct ipmi_smi_msg *msg;
1041	unsigned long oflags;
1042
1043	restart:
1044	if (!IS_SSIF_IDLE(ssif_info)) {
1045	ipmi_ssif_unlock_cond(ssif_info, flags);
1046	return;
1047	}
1048
1049	if (!ssif_info->waiting_msg) {
1050	ssif_info->curr_msg = NULL;
1051	ipmi_ssif_unlock_cond(ssif_info, flags);
1052	} else {
1053	int rv;
1054
1055	ssif_info->curr_msg = ssif_info->waiting_msg;
1056	ssif_info->waiting_msg = NULL;
1057	ipmi_ssif_unlock_cond(ssif_info, flags);
1058	rv = start_send(ssif_info,
1059	data: ssif_info->curr_msg->data,
1060	len: ssif_info->curr_msg->data_size);
1061	if (rv) {
1062	msg = ssif_info->curr_msg;
1063	ssif_info->curr_msg = NULL;
1064	return_hosed_msg(ssif_info, msg);
1065	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
1066	goto restart;
1067	}
1068	}
1069	}
1070
1071	static void sender(void *send_info,
1072	struct ipmi_smi_msg *msg)
1073	{
1074	struct ssif_info *ssif_info = send_info;
1075	unsigned long oflags, *flags;
1076
1077	BUG_ON(ssif_info->waiting_msg);
1078	ssif_info->waiting_msg = msg;
1079
1080	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
1081	start_next_msg(ssif_info, flags);
1082
1083	if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1084	struct timespec64 t;
1085
1086	ktime_get_real_ts64(tv: &t);
1087	dev_dbg(&ssif_info->client->dev,
1088	"**Enqueue %02x %02x: %lld.%6.6ld\n",
1089	msg->data[0], msg->data[1],
1090	(long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1091	}
1092	}
1093
1094	static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1095	{
1096	struct ssif_info *ssif_info = send_info;
1097
1098	data->addr_src = ssif_info->addr_source;
1099	data->dev = &ssif_info->client->dev;
1100	data->addr_info = ssif_info->addr_info;
1101	get_device(dev: data->dev);
1102
1103	return 0;
1104	}
1105
1106	/*
1107	* Upper layer wants us to request events.
1108	*/
1109	static void request_events(void *send_info)
1110	{
1111	struct ssif_info *ssif_info = send_info;
1112	unsigned long oflags, *flags;
1113
1114	if (!ssif_info->has_event_buffer)
1115	return;
1116
1117	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
1118	ssif_info->req_events = true;
1119	ipmi_ssif_unlock_cond(ssif_info, flags);
1120	}
1121
1122	/*
1123	* Upper layer is changing the flag saying whether we need to request
1124	* flags periodically or not.
1125	*/
1126	static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
1127	{
1128	struct ssif_info *ssif_info = send_info;
1129	unsigned long oflags, *flags;
1130	long timeout = 0;
1131
1132	if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
1133	timeout = SSIF_WATCH_MSG_TIMEOUT;
1134	else if (watch_mask)
1135	timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
1136
1137	flags = ipmi_ssif_lock_cond(ssif_info, flags: &oflags);
1138	if (timeout != ssif_info->watch_timeout) {
1139	ssif_info->watch_timeout = timeout;
1140	if (ssif_info->watch_timeout)
1141	mod_timer(timer: &ssif_info->watch_timer,
1142	expires: jiffies + ssif_info->watch_timeout);
1143	}
1144	ipmi_ssif_unlock_cond(ssif_info, flags);
1145	}
1146
1147	static int ssif_start_processing(void *send_info,
1148	struct ipmi_smi *intf)
1149	{
1150	struct ssif_info *ssif_info = send_info;
1151
1152	ssif_info->intf = intf;
1153
1154	return 0;
1155	}
1156
1157	#define MAX_SSIF_BMCS 4
1158
1159	static unsigned short addr[MAX_SSIF_BMCS];
1160	static int num_addrs;
1161	module_param_array(addr, ushort, &num_addrs, 0);
1162	MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1163
1164	static char *adapter_name[MAX_SSIF_BMCS];
1165	static int num_adapter_names;
1166	module_param_array(adapter_name, charp, &num_adapter_names, 0);
1167	MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC. By default all devices are scanned.");
1168
1169	static int slave_addrs[MAX_SSIF_BMCS];
1170	static int num_slave_addrs;
1171	module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1172	MODULE_PARM_DESC(slave_addrs,
1173	"The default IPMB slave address for the controller.");
1174
1175	static bool alerts_broken;
1176	module_param(alerts_broken, bool, 0);
1177	MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1178
1179	/*
1180	* Bit 0 enables message debugging, bit 1 enables state debugging, and
1181	* bit 2 enables timing debugging. This is an array indexed by
1182	* interface number"
1183	*/
1184	static int dbg[MAX_SSIF_BMCS];
1185	static int num_dbg;
1186	module_param_array(dbg, int, &num_dbg, 0);
1187	MODULE_PARM_DESC(dbg, "Turn on debugging.");
1188
1189	static bool ssif_dbg_probe;
1190	module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1191	MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1192
1193	static bool ssif_tryacpi = true;
1194	module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1195	MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1196
1197	static bool ssif_trydmi = true;
1198	module_param_named(trydmi, ssif_trydmi, bool, 0);
1199	MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1200
1201	static DEFINE_MUTEX(ssif_infos_mutex);
1202	static LIST_HEAD(ssif_infos);
1203
1204	#define IPMI_SSIF_ATTR(name) \
1205	static ssize_t ipmi_##name##_show(struct device *dev, \
1206	struct device_attribute *attr, \
1207	char *buf) \
1208	{ \
1209	struct ssif_info *ssif_info = dev_get_drvdata(dev); \
1210	\
1211	return sysfs_emit(buf, "%u\n", ssif_get_stat(ssif_info, name));\
1212	} \
1213	static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1214
1215	static ssize_t ipmi_type_show(struct device *dev,
1216	struct device_attribute *attr,
1217	char *buf)
1218	{
1219	return sysfs_emit(buf, fmt: "ssif\n");
1220	}
1221	static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1222
1223	IPMI_SSIF_ATTR(sent_messages);
1224	IPMI_SSIF_ATTR(sent_messages_parts);
1225	IPMI_SSIF_ATTR(send_retries);
1226	IPMI_SSIF_ATTR(send_errors);
1227	IPMI_SSIF_ATTR(received_messages);
1228	IPMI_SSIF_ATTR(received_message_parts);
1229	IPMI_SSIF_ATTR(receive_retries);
1230	IPMI_SSIF_ATTR(receive_errors);
1231	IPMI_SSIF_ATTR(flag_fetches);
1232	IPMI_SSIF_ATTR(hosed);
1233	IPMI_SSIF_ATTR(events);
1234	IPMI_SSIF_ATTR(watchdog_pretimeouts);
1235	IPMI_SSIF_ATTR(alerts);
1236
1237	static struct attribute *ipmi_ssif_dev_attrs[] = {
1238	&dev_attr_type.attr,
1239	&dev_attr_sent_messages.attr,
1240	&dev_attr_sent_messages_parts.attr,
1241	&dev_attr_send_retries.attr,
1242	&dev_attr_send_errors.attr,
1243	&dev_attr_received_messages.attr,
1244	&dev_attr_received_message_parts.attr,
1245	&dev_attr_receive_retries.attr,
1246	&dev_attr_receive_errors.attr,
1247	&dev_attr_flag_fetches.attr,
1248	&dev_attr_hosed.attr,
1249	&dev_attr_events.attr,
1250	&dev_attr_watchdog_pretimeouts.attr,
1251	&dev_attr_alerts.attr,
1252	NULL
1253	};
1254
1255	static const struct attribute_group ipmi_ssif_dev_attr_group = {
1256	.attrs = ipmi_ssif_dev_attrs,
1257	};
1258
1259	static void shutdown_ssif(void *send_info)
1260	{
1261	struct ssif_info *ssif_info = send_info;
1262
1263	device_remove_group(dev: &ssif_info->client->dev, grp: &ipmi_ssif_dev_attr_group);
1264	dev_set_drvdata(dev: &ssif_info->client->dev, NULL);
1265
1266	/* make sure the driver is not looking for flags any more. */
1267	while (ssif_info->ssif_state != SSIF_IDLE)
1268	schedule_timeout(timeout: 1);
1269
1270	ssif_info->stopping = true;
1271	del_timer_sync(timer: &ssif_info->watch_timer);
1272	del_timer_sync(timer: &ssif_info->retry_timer);
1273	if (ssif_info->thread) {
1274	complete(&ssif_info->wake_thread);
1275	kthread_stop(k: ssif_info->thread);
1276	}
1277	}
1278
1279	static void ssif_remove(struct i2c_client *client)
1280	{
1281	struct ssif_info *ssif_info = i2c_get_clientdata(client);
1282	struct ssif_addr_info *addr_info;
1283
1284	/*
1285	* After this point, we won't deliver anything asynchronously
1286	* to the message handler. We can unregister ourself.
1287	*/
1288	ipmi_unregister_smi(intf: ssif_info->intf);
1289
1290	list_for_each_entry(addr_info, &ssif_infos, link) {
1291	if (addr_info->client == client) {
1292	addr_info->client = NULL;
1293	break;
1294	}
1295	}
1296
1297	kfree(objp: ssif_info);
1298	}
1299
1300	static int read_response(struct i2c_client *client, unsigned char *resp)
1301	{
1302	int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1303
1304	while (retry_cnt > 0) {
1305	ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1306	values: resp);
1307	if (ret > 0)
1308	break;
1309	msleep(SSIF_MSG_MSEC);
1310	retry_cnt--;
1311	if (retry_cnt <= 0)
1312	break;
1313	}
1314
1315	return ret;
1316	}
1317
1318	static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1319	int *resp_len, unsigned char *resp)
1320	{
1321	int retry_cnt;
1322	int ret;
1323
1324	retry_cnt = SSIF_SEND_RETRIES;
1325	retry1:
1326	ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, length: len, values: msg);
1327	if (ret) {
1328	retry_cnt--;
1329	if (retry_cnt > 0) {
1330	msleep(SSIF_REQ_RETRY_MSEC);
1331	goto retry1;
1332	}
1333	return -ENODEV;
1334	}
1335
1336	ret = read_response(client, resp);
1337	if (ret > 0) {
1338	/* Validate that the response is correct. */
1339	if (ret < 3 ||
1340	(resp[0] != (msg[0] | (1 << 2))) ||
1341	(resp[1] != msg[1]))
1342	ret = -EINVAL;
1343	else if (ret > IPMI_MAX_MSG_LENGTH) {
1344	ret = -E2BIG;
1345	} else {
1346	*resp_len = ret;
1347	ret = 0;
1348	}
1349	}
1350
1351	return ret;
1352	}
1353
1354	static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1355	{
1356	unsigned char *resp;
1357	unsigned char msg[3];
1358	int rv;
1359	int len;
1360
1361	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1362	if (!resp)
1363	return -ENOMEM;
1364
1365	/* Do a Get Device ID command, since it is required. */
1366	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1367	msg[1] = IPMI_GET_DEVICE_ID_CMD;
1368	rv = do_cmd(client, len: 2, msg, resp_len: &len, resp);
1369	if (rv)
1370	rv = -ENODEV;
1371	else
1372	strscpy(p: info->type, DEVICE_NAME, I2C_NAME_SIZE);
1373	kfree(objp: resp);
1374	return rv;
1375	}
1376
1377	static int strcmp_nospace(char *s1, char *s2)
1378	{
1379	while (*s1 && *s2) {
1380	while (isspace(*s1))
1381	s1++;
1382	while (isspace(*s2))
1383	s2++;
1384	if (*s1 > *s2)
1385	return 1;
1386	if (*s1 < *s2)
1387	return -1;
1388	s1++;
1389	s2++;
1390	}
1391	return 0;
1392	}
1393
1394	static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1395	char *adapter_name,
1396	bool match_null_name)
1397	{
1398	struct ssif_addr_info *info, *found = NULL;
1399
1400	restart:
1401	list_for_each_entry(info, &ssif_infos, link) {
1402	if (info->binfo.addr == addr) {
1403	if (info->addr_src == SI_SMBIOS && !info->adapter_name)
1404	info->adapter_name = kstrdup(s: adapter_name,
1405	GFP_KERNEL);
1406
1407	if (info->adapter_name || adapter_name) {
1408	if (!info->adapter_name != !adapter_name) {
1409	/* One is NULL and one is not */
1410	continue;
1411	}
1412	if (adapter_name &&
1413	strcmp_nospace(s1: info->adapter_name,
1414	s2: adapter_name))
1415	/* Names do not match */
1416	continue;
1417	}
1418	found = info;
1419	break;
1420	}
1421	}
1422
1423	if (!found && match_null_name) {
1424	/* Try to get an exact match first, then try with a NULL name */
1425	adapter_name = NULL;
1426	match_null_name = false;
1427	goto restart;
1428	}
1429
1430	return found;
1431	}
1432
1433	static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1434	{
1435	#ifdef CONFIG_ACPI
1436	acpi_handle acpi_handle;
1437
1438	acpi_handle = ACPI_HANDLE(dev);
1439	if (acpi_handle) {
1440	ssif_info->addr_source = SI_ACPI;
1441	ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1442	request_module_nowait("acpi_ipmi");
1443	return true;
1444	}
1445	#endif
1446	return false;
1447	}
1448
1449	static int find_slave_address(struct i2c_client *client, int slave_addr)
1450	{
1451	#ifdef CONFIG_IPMI_DMI_DECODE
1452	if (!slave_addr)
1453	slave_addr = ipmi_dmi_get_slave_addr(
1454	si_type: SI_TYPE_INVALID,
1455	space: i2c_adapter_id(adap: client->adapter),
1456	base_addr: client->addr);
1457	#endif
1458
1459	return slave_addr;
1460	}
1461
1462	static int start_multipart_test(struct i2c_client *client,
1463	unsigned char *msg, bool do_middle)
1464	{
1465	int retry_cnt = SSIF_SEND_RETRIES, ret;
1466
1467	retry_write:
1468	ret = i2c_smbus_write_block_data(client,
1469	SSIF_IPMI_MULTI_PART_REQUEST_START,
1470	length: 32, values: msg);
1471	if (ret) {
1472	retry_cnt--;
1473	if (retry_cnt > 0) {
1474	msleep(SSIF_REQ_RETRY_MSEC);
1475	goto retry_write;
1476	}
1477	dev_err(&client->dev, "Could not write multi-part start, though the BMC said it could handle it. Just limit sends to one part.\n");
1478	return ret;
1479	}
1480
1481	if (!do_middle)
1482	return 0;
1483
1484	ret = i2c_smbus_write_block_data(client,
1485	SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1486	length: 32, values: msg + 32);
1487	if (ret) {
1488	dev_err(&client->dev, "Could not write multi-part middle, though the BMC said it could handle it. Just limit sends to one part.\n");
1489	return ret;
1490	}
1491
1492	return 0;
1493	}
1494
1495	static void test_multipart_messages(struct i2c_client *client,
1496	struct ssif_info *ssif_info,
1497	unsigned char *resp)
1498	{
1499	unsigned char msg[65];
1500	int ret;
1501	bool do_middle;
1502
1503	if (ssif_info->max_xmit_msg_size <= 32)
1504	return;
1505
1506	do_middle = ssif_info->max_xmit_msg_size > 63;
1507
1508	memset(msg, 0, sizeof(msg));
1509	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1510	msg[1] = IPMI_GET_DEVICE_ID_CMD;
1511
1512	/*
1513	* The specification is all messed up dealing with sending
1514	* multi-part messages. Per what the specification says, it
1515	* is impossible to send a message that is a multiple of 32
1516	* bytes, except for 32 itself. It talks about a "start"
1517	* transaction (cmd=6) that must be 32 bytes, "middle"
1518	* transaction (cmd=7) that must be 32 bytes, and an "end"
1519	* transaction. The "end" transaction is shown as cmd=7 in
1520	* the text, but if that's the case there is no way to
1521	* differentiate between a middle and end part except the
1522	* length being less than 32. But there is a table at the far
1523	* end of the section (that I had never noticed until someone
1524	* pointed it out to me) that mentions it as cmd=8.
1525	*
1526	* After some thought, I think the example is wrong and the
1527	* end transaction should be cmd=8. But some systems don't
1528	* implement cmd=8, they use a zero-length end transaction,
1529	* even though that violates the SMBus specification.
1530	*
1531	* So, to work around this, this code tests if cmd=8 works.
1532	* If it does, then we use that. If not, it tests zero-
1533	* byte end transactions. If that works, good. If not,
1534	* we only allow 63-byte transactions max.
1535	*/
1536
1537	ret = start_multipart_test(client, msg, do_middle);
1538	if (ret)
1539	goto out_no_multi_part;
1540
1541	ret = i2c_smbus_write_block_data(client,
1542	SSIF_IPMI_MULTI_PART_REQUEST_END,
1543	length: 1, values: msg + 64);
1544
1545	if (!ret)
1546	ret = read_response(client, resp);
1547
1548	if (ret > 0) {
1549	/* End transactions work, we are good. */
1550	ssif_info->cmd8_works = true;
1551	return;
1552	}
1553
1554	ret = start_multipart_test(client, msg, do_middle);
1555	if (ret) {
1556	dev_err(&client->dev, "Second multipart test failed.\n");
1557	goto out_no_multi_part;
1558	}
1559
1560	ret = i2c_smbus_write_block_data(client,
1561	SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1562	length: 0, values: msg + 64);
1563	if (!ret)
1564	ret = read_response(client, resp);
1565	if (ret > 0)
1566	/* Zero-size end parts work, use those. */
1567	return;
1568
1569	/* Limit to 63 bytes and use a short middle command to mark the end. */
1570	if (ssif_info->max_xmit_msg_size > 63)
1571	ssif_info->max_xmit_msg_size = 63;
1572	return;
1573
1574	out_no_multi_part:
1575	ssif_info->max_xmit_msg_size = 32;
1576	return;
1577	}
1578
1579	/*
1580	* Global enables we care about.
1581	*/
1582	#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1583	IPMI_BMC_EVT_MSG_INTR)
1584
1585	static void ssif_remove_dup(struct i2c_client *client)
1586	{
1587	struct ssif_info *ssif_info = i2c_get_clientdata(client);
1588
1589	ipmi_unregister_smi(intf: ssif_info->intf);
1590	kfree(objp: ssif_info);
1591	}
1592
1593	static int ssif_add_infos(struct i2c_client *client)
1594	{
1595	struct ssif_addr_info *info;
1596
1597	info = kzalloc(size: sizeof(*info), GFP_KERNEL);
1598	if (!info)
1599	return -ENOMEM;
1600	info->addr_src = SI_ACPI;
1601	info->client = client;
1602	info->adapter_name = kstrdup(s: client->adapter->name, GFP_KERNEL);
1603	if (!info->adapter_name) {
1604	kfree(objp: info);
1605	return -ENOMEM;
1606	}
1607
1608	info->binfo.addr = client->addr;
1609	list_add_tail(new: &info->link, head: &ssif_infos);
1610	return 0;
1611	}
1612
1613	/*
1614	* Prefer ACPI over SMBIOS, if both are available.
1615	* So if we get an ACPI interface and have already registered a SMBIOS
1616	* interface at the same address, remove the SMBIOS and add the ACPI one.
1617	*/
1618	static int ssif_check_and_remove(struct i2c_client *client,
1619	struct ssif_info *ssif_info)
1620	{
1621	struct ssif_addr_info *info;
1622
1623	list_for_each_entry(info, &ssif_infos, link) {
1624	if (!info->client)
1625	return 0;
1626	if (!strcmp(info->adapter_name, client->adapter->name) &&
1627	info->binfo.addr == client->addr) {
1628	if (info->addr_src == SI_ACPI)
1629	return -EEXIST;
1630
1631	if (ssif_info->addr_source == SI_ACPI &&
1632	info->addr_src == SI_SMBIOS) {
1633	dev_info(&client->dev,
1634	"Removing %s-specified SSIF interface in favor of ACPI\n",
1635	ipmi_addr_src_to_str(info->addr_src));
1636	ssif_remove_dup(client: info->client);
1637	return 0;
1638	}
1639	}
1640	}
1641	return 0;
1642	}
1643
1644	static int ssif_probe(struct i2c_client *client)
1645	{
1646	unsigned char msg[3];
1647	unsigned char *resp;
1648	struct ssif_info *ssif_info;
1649	int rv = 0;
1650	int len = 0;
1651	int i;
1652	u8 slave_addr = 0;
1653	struct ssif_addr_info *addr_info = NULL;
1654
1655	mutex_lock(&ssif_infos_mutex);
1656	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1657	if (!resp) {
1658	mutex_unlock(lock: &ssif_infos_mutex);
1659	return -ENOMEM;
1660	}
1661
1662	ssif_info = kzalloc(size: sizeof(*ssif_info), GFP_KERNEL);
1663	if (!ssif_info) {
1664	kfree(objp: resp);
1665	mutex_unlock(lock: &ssif_infos_mutex);
1666	return -ENOMEM;
1667	}
1668
1669	if (!check_acpi(ssif_info, dev: &client->dev)) {
1670	addr_info = ssif_info_find(addr: client->addr, adapter_name: client->adapter->name,
1671	match_null_name: true);
1672	if (!addr_info) {
1673	/* Must have come in through sysfs. */
1674	ssif_info->addr_source = SI_HOTMOD;
1675	} else {
1676	ssif_info->addr_source = addr_info->addr_src;
1677	ssif_info->ssif_debug = addr_info->debug;
1678	ssif_info->addr_info = addr_info->addr_info;
1679	addr_info->client = client;
1680	slave_addr = addr_info->slave_addr;
1681	}
1682	}
1683
1684	ssif_info->client = client;
1685	i2c_set_clientdata(client, data: ssif_info);
1686
1687	rv = ssif_check_and_remove(client, ssif_info);
1688	/* If rv is 0 and addr source is not SI_ACPI, continue probing */
1689	if (!rv && ssif_info->addr_source == SI_ACPI) {
1690	rv = ssif_add_infos(client);
1691	if (rv) {
1692	dev_err(&client->dev, "Out of memory!, exiting ..\n");
1693	goto out;
1694	}
1695	} else if (rv) {
1696	dev_err(&client->dev, "Not probing, Interface already present\n");
1697	goto out;
1698	}
1699
1700	slave_addr = find_slave_address(client, slave_addr);
1701
1702	dev_info(&client->dev,
1703	"Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1704	ipmi_addr_src_to_str(ssif_info->addr_source),
1705	client->addr, client->adapter->name, slave_addr);
1706
1707	/* Now check for system interface capabilities */
1708	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1709	msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1710	msg[2] = 0; /* SSIF */
1711	rv = do_cmd(client, len: 3, msg, resp_len: &len, resp);
1712	if (!rv && (len >= 3) && (resp[2] == 0)) {
1713	if (len < 7) {
1714	if (ssif_dbg_probe)
1715	dev_dbg(&ssif_info->client->dev,
1716	"SSIF info too short: %d\n", len);
1717	goto no_support;
1718	}
1719
1720	/* Got a good SSIF response, handle it. */
1721	ssif_info->max_xmit_msg_size = resp[5];
1722	ssif_info->max_recv_msg_size = resp[6];
1723	ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1724	ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1725
1726	/* Sanitize the data */
1727	switch (ssif_info->multi_support) {
1728	case SSIF_NO_MULTI:
1729	if (ssif_info->max_xmit_msg_size > 32)
1730	ssif_info->max_xmit_msg_size = 32;
1731	if (ssif_info->max_recv_msg_size > 32)
1732	ssif_info->max_recv_msg_size = 32;
1733	break;
1734
1735	case SSIF_MULTI_2_PART:
1736	if (ssif_info->max_xmit_msg_size > 63)
1737	ssif_info->max_xmit_msg_size = 63;
1738	if (ssif_info->max_recv_msg_size > 62)
1739	ssif_info->max_recv_msg_size = 62;
1740	break;
1741
1742	case SSIF_MULTI_n_PART:
1743	/* We take whatever size given, but do some testing. */
1744	break;
1745
1746	default:
1747	/* Data is not sane, just give up. */
1748	goto no_support;
1749	}
1750	} else {
1751	no_support:
1752	/* Assume no multi-part or PEC support */
1753	dev_info(&ssif_info->client->dev,
1754	"Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1755	rv, len, resp[2]);
1756
1757	ssif_info->max_xmit_msg_size = 32;
1758	ssif_info->max_recv_msg_size = 32;
1759	ssif_info->multi_support = SSIF_NO_MULTI;
1760	ssif_info->supports_pec = 0;
1761	}
1762
1763	test_multipart_messages(client, ssif_info, resp);
1764
1765	/* Make sure the NMI timeout is cleared. */
1766	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1767	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1768	msg[2] = WDT_PRE_TIMEOUT_INT;
1769	rv = do_cmd(client, len: 3, msg, resp_len: &len, resp);
1770	if (rv || (len < 3) || (resp[2] != 0))
1771	dev_warn(&ssif_info->client->dev,
1772	"Unable to clear message flags: %d %d %2.2x\n",
1773	rv, len, resp[2]);
1774
1775	/* Attempt to enable the event buffer. */
1776	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1777	msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1778	rv = do_cmd(client, len: 2, msg, resp_len: &len, resp);
1779	if (rv || (len < 4) || (resp[2] != 0)) {
1780	dev_warn(&ssif_info->client->dev,
1781	"Error getting global enables: %d %d %2.2x\n",
1782	rv, len, resp[2]);
1783	rv = 0; /* Not fatal */
1784	goto found;
1785	}
1786
1787	ssif_info->global_enables = resp[3];
1788
1789	if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1790	ssif_info->has_event_buffer = true;
1791	/* buffer is already enabled, nothing to do. */
1792	goto found;
1793	}
1794
1795	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1796	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1797	msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1798	rv = do_cmd(client, len: 3, msg, resp_len: &len, resp);
1799	if (rv || (len < 2)) {
1800	dev_warn(&ssif_info->client->dev,
1801	"Error setting global enables: %d %d %2.2x\n",
1802	rv, len, resp[2]);
1803	rv = 0; /* Not fatal */
1804	goto found;
1805	}
1806
1807	if (resp[2] == 0) {
1808	/* A successful return means the event buffer is supported. */
1809	ssif_info->has_event_buffer = true;
1810	ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1811	}
1812
1813	/* Some systems don't behave well if you enable alerts. */
1814	if (alerts_broken)
1815	goto found;
1816
1817	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1818	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1819	msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1820	rv = do_cmd(client, len: 3, msg, resp_len: &len, resp);
1821	if (rv || (len < 2)) {
1822	dev_warn(&ssif_info->client->dev,
1823	"Error setting global enables: %d %d %2.2x\n",
1824	rv, len, resp[2]);
1825	rv = 0; /* Not fatal */
1826	goto found;
1827	}
1828
1829	if (resp[2] == 0) {
1830	/* A successful return means the alert is supported. */
1831	ssif_info->supports_alert = true;
1832	ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1833	}
1834
1835	found:
1836	if (ssif_dbg_probe) {
1837	dev_dbg(&ssif_info->client->dev,
1838	"%s: i2c_probe found device at i2c address %x\n",
1839	__func__, client->addr);
1840	}
1841
1842	spin_lock_init(&ssif_info->lock);
1843	ssif_info->ssif_state = SSIF_IDLE;
1844	timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1845	timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1846
1847	for (i = 0; i < SSIF_NUM_STATS; i++)
1848	atomic_set(v: &ssif_info->stats[i], i: 0);
1849
1850	if (ssif_info->supports_pec)
1851	ssif_info->client->flags |= I2C_CLIENT_PEC;
1852
1853	ssif_info->handlers.owner = THIS_MODULE;
1854	ssif_info->handlers.start_processing = ssif_start_processing;
1855	ssif_info->handlers.shutdown = shutdown_ssif;
1856	ssif_info->handlers.get_smi_info = get_smi_info;
1857	ssif_info->handlers.sender = sender;
1858	ssif_info->handlers.request_events = request_events;
1859	ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1860
1861	{
1862	unsigned int thread_num;
1863
1864	thread_num = ((i2c_adapter_id(adap: ssif_info->client->adapter)
1865	<< 8) |
1866	ssif_info->client->addr);
1867	init_completion(x: &ssif_info->wake_thread);
1868	ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1869	"kssif%4.4x", thread_num);
1870	if (IS_ERR(ptr: ssif_info->thread)) {
1871	rv = PTR_ERR(ptr: ssif_info->thread);
1872	dev_notice(&ssif_info->client->dev,
1873	"Could not start kernel thread: error %d\n",
1874	rv);
1875	goto out;
1876	}
1877	}
1878
1879	dev_set_drvdata(dev: &ssif_info->client->dev, data: ssif_info);
1880	rv = device_add_group(dev: &ssif_info->client->dev,
1881	grp: &ipmi_ssif_dev_attr_group);
1882	if (rv) {
1883	dev_err(&ssif_info->client->dev,
1884	"Unable to add device attributes: error %d\n",
1885	rv);
1886	goto out;
1887	}
1888
1889	rv = ipmi_register_smi(&ssif_info->handlers,
1890	ssif_info,
1891	&ssif_info->client->dev,
1892	slave_addr);
1893	if (rv) {
1894	dev_err(&ssif_info->client->dev,
1895	"Unable to register device: error %d\n", rv);
1896	goto out_remove_attr;
1897	}
1898
1899	out:
1900	if (rv) {
1901	if (addr_info)
1902	addr_info->client = NULL;
1903
1904	dev_err(&ssif_info->client->dev,
1905	"Unable to start IPMI SSIF: %d\n", rv);
1906	i2c_set_clientdata(client, NULL);
1907	kfree(objp: ssif_info);
1908	}
1909	kfree(objp: resp);
1910	mutex_unlock(lock: &ssif_infos_mutex);
1911	return rv;
1912
1913	out_remove_attr:
1914	device_remove_group(dev: &ssif_info->client->dev, grp: &ipmi_ssif_dev_attr_group);
1915	dev_set_drvdata(dev: &ssif_info->client->dev, NULL);
1916	goto out;
1917	}
1918
1919	static int new_ssif_client(int addr, char *adapter_name,
1920	int debug, int slave_addr,
1921	enum ipmi_addr_src addr_src,
1922	struct device *dev)
1923	{
1924	struct ssif_addr_info *addr_info;
1925	int rv = 0;
1926
1927	mutex_lock(&ssif_infos_mutex);
1928	if (ssif_info_find(addr, adapter_name, match_null_name: false)) {
1929	rv = -EEXIST;
1930	goto out_unlock;
1931	}
1932
1933	addr_info = kzalloc(size: sizeof(*addr_info), GFP_KERNEL);
1934	if (!addr_info) {
1935	rv = -ENOMEM;
1936	goto out_unlock;
1937	}
1938
1939	if (adapter_name) {
1940	addr_info->adapter_name = kstrdup(s: adapter_name, GFP_KERNEL);
1941	if (!addr_info->adapter_name) {
1942	kfree(objp: addr_info);
1943	rv = -ENOMEM;
1944	goto out_unlock;
1945	}
1946	}
1947
1948	strscpy(p: addr_info->binfo.type, DEVICE_NAME,
1949	size: sizeof(addr_info->binfo.type));
1950	addr_info->binfo.addr = addr;
1951	addr_info->binfo.platform_data = addr_info;
1952	addr_info->debug = debug;
1953	addr_info->slave_addr = slave_addr;
1954	addr_info->addr_src = addr_src;
1955	addr_info->dev = dev;
1956
1957	if (dev)
1958	dev_set_drvdata(dev, data: addr_info);
1959
1960	list_add_tail(new: &addr_info->link, head: &ssif_infos);
1961
1962	/* Address list will get it */
1963
1964	out_unlock:
1965	mutex_unlock(lock: &ssif_infos_mutex);
1966	return rv;
1967	}
1968
1969	static void free_ssif_clients(void)
1970	{
1971	struct ssif_addr_info *info, *tmp;
1972
1973	mutex_lock(&ssif_infos_mutex);
1974	list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1975	list_del(entry: &info->link);
1976	kfree(objp: info->adapter_name);
1977	kfree(objp: info);
1978	}
1979	mutex_unlock(lock: &ssif_infos_mutex);
1980	}
1981
1982	static unsigned short *ssif_address_list(void)
1983	{
1984	struct ssif_addr_info *info;
1985	unsigned int count = 0, i = 0;
1986	unsigned short *address_list;
1987
1988	list_for_each_entry(info, &ssif_infos, link)
1989	count++;
1990
1991	address_list = kcalloc(n: count + 1, size: sizeof(*address_list),
1992	GFP_KERNEL);
1993	if (!address_list)
1994	return NULL;
1995
1996	list_for_each_entry(info, &ssif_infos, link) {
1997	unsigned short addr = info->binfo.addr;
1998	int j;
1999
2000	for (j = 0; j < i; j++) {
2001	if (address_list[j] == addr)
2002	/* Found a dup. */
2003	break;
2004	}
2005	if (j == i) /* Didn't find it in the list. */
2006	address_list[i++] = addr;
2007	}
2008	address_list[i] = I2C_CLIENT_END;
2009
2010	return address_list;
2011	}
2012
2013	#ifdef CONFIG_ACPI
2014	static const struct acpi_device_id ssif_acpi_match[] = {
2015	{ "IPI0001", 0 },
2016	{ },
2017	};
2018	MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
2019	#endif
2020
2021	#ifdef CONFIG_DMI
2022	static int dmi_ipmi_probe(struct platform_device *pdev)
2023	{
2024	u8 slave_addr = 0;
2025	u16 i2c_addr;
2026	int rv;
2027
2028	if (!ssif_trydmi)
2029	return -ENODEV;
2030
2031	rv = device_property_read_u16(dev: &pdev->dev, propname: "i2c-addr", val: &i2c_addr);
2032	if (rv) {
2033	dev_warn(&pdev->dev, "No i2c-addr property\n");
2034	return -ENODEV;
2035	}
2036
2037	rv = device_property_read_u8(dev: &pdev->dev, propname: "slave-addr", val: &slave_addr);
2038	if (rv)
2039	slave_addr = 0x20;
2040
2041	return new_ssif_client(addr: i2c_addr, NULL, debug: 0,
2042	slave_addr, addr_src: SI_SMBIOS, dev: &pdev->dev);
2043	}
2044	#else
2045	static int dmi_ipmi_probe(struct platform_device *pdev)
2046	{
2047	return -ENODEV;
2048	}
2049	#endif
2050
2051	static const struct i2c_device_id ssif_id[] = {
2052	{ DEVICE_NAME, 0 },
2053	{ }
2054	};
2055	MODULE_DEVICE_TABLE(i2c, ssif_id);
2056
2057	static struct i2c_driver ssif_i2c_driver = {
2058	.class = I2C_CLASS_HWMON,
2059	.driver = {
2060	.name = DEVICE_NAME
2061	},
2062	.probe = ssif_probe,
2063	.remove = ssif_remove,
2064	.alert = ssif_alert,
2065	.id_table = ssif_id,
2066	.detect = ssif_detect
2067	};
2068
2069	static int ssif_platform_probe(struct platform_device *dev)
2070	{
2071	return dmi_ipmi_probe(pdev: dev);
2072	}
2073
2074	static int ssif_platform_remove(struct platform_device *dev)
2075	{
2076	struct ssif_addr_info *addr_info = dev_get_drvdata(dev: &dev->dev);
2077
2078	mutex_lock(&ssif_infos_mutex);
2079	list_del(entry: &addr_info->link);
2080	kfree(objp: addr_info);
2081	mutex_unlock(lock: &ssif_infos_mutex);
2082	return 0;
2083	}
2084
2085	static const struct platform_device_id ssif_plat_ids[] = {
2086	{ "dmi-ipmi-ssif", 0 },
2087	{ }
2088	};
2089
2090	static struct platform_driver ipmi_driver = {
2091	.driver = {
2092	.name = DEVICE_NAME,
2093	},
2094	.probe = ssif_platform_probe,
2095	.remove = ssif_platform_remove,
2096	.id_table = ssif_plat_ids
2097	};
2098
2099	static int __init init_ipmi_ssif(void)
2100	{
2101	int i;
2102	int rv;
2103
2104	if (initialized)
2105	return 0;
2106
2107	pr_info("IPMI SSIF Interface driver\n");
2108
2109	/* build list for i2c from addr list */
2110	for (i = 0; i < num_addrs; i++) {
2111	rv = new_ssif_client(addr: addr[i], adapter_name: adapter_name[i],
2112	debug: dbg[i], slave_addr: slave_addrs[i],
2113	addr_src: SI_HARDCODED, NULL);
2114	if (rv)
2115	pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2116	addr[i]);
2117	}
2118
2119	if (ssif_tryacpi)
2120	ssif_i2c_driver.driver.acpi_match_table =
2121	ACPI_PTR(ssif_acpi_match);
2122
2123	if (ssif_trydmi) {
2124	rv = platform_driver_register(&ipmi_driver);
2125	if (rv)
2126	pr_err("Unable to register driver: %d\n", rv);
2127	else
2128	platform_registered = true;
2129	}
2130
2131	ssif_i2c_driver.address_list = ssif_address_list();
2132
2133	rv = i2c_add_driver(&ssif_i2c_driver);
2134	if (!rv)
2135	initialized = true;
2136
2137	return rv;
2138	}
2139	module_init(init_ipmi_ssif);
2140
2141	static void __exit cleanup_ipmi_ssif(void)
2142	{
2143	if (!initialized)
2144	return;
2145
2146	initialized = false;
2147
2148	i2c_del_driver(driver: &ssif_i2c_driver);
2149
2150	kfree(objp: ssif_i2c_driver.address_list);
2151
2152	if (ssif_trydmi && platform_registered)
2153	platform_driver_unregister(&ipmi_driver);
2154
2155	free_ssif_clients();
2156	}
2157	module_exit(cleanup_ipmi_ssif);
2158
2159	MODULE_ALIAS("platform:dmi-ipmi-ssif");
2160	MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2161	MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2162	MODULE_LICENSE("GPL");
2163