1/*
2 * ipmi_ssif.c
3 *
4 * The interface to the IPMI driver for SMBus access to a SMBus
5 * compliant device.  Called SSIF by the IPMI spec.
6 *
7 * Author: Intel Corporation
8 *         Todd Davis <todd.c.davis@intel.com>
9 *
10 * Rewritten by Corey Minyard <minyard@acm.org> to support the
11 * non-blocking I2C interface, add support for multi-part
12 * transactions, add PEC support, and general clenaup.
13 *
14 * Copyright 2003 Intel Corporation
15 * Copyright 2005 MontaVista Software
16 *
17 *  This program is free software; you can redistribute it and/or modify it
18 *  under the terms of the GNU General Public License as published by the
19 *  Free Software Foundation; either version 2 of the License, or (at your
20 *  option) any later version.
21 */
22
23/*
24 * This file holds the "policy" for the interface to the SSIF state
25 * machine.  It does the configuration, handles timers and interrupts,
26 * and drives the real SSIF state machine.
27 */
28
29/*
30 * TODO: Figure out how to use SMB alerts.  This will require a new
31 * interface into the I2C driver, I believe.
32 */
33
34#if defined(MODVERSIONS)
35#include <linux/modversions.h>
36#endif
37
38#include <linux/module.h>
39#include <linux/moduleparam.h>
40#include <linux/sched.h>
41#include <linux/seq_file.h>
42#include <linux/timer.h>
43#include <linux/delay.h>
44#include <linux/errno.h>
45#include <linux/spinlock.h>
46#include <linux/slab.h>
47#include <linux/list.h>
48#include <linux/i2c.h>
49#include <linux/ipmi_smi.h>
50#include <linux/init.h>
51#include <linux/dmi.h>
52#include <linux/kthread.h>
53#include <linux/acpi.h>
54#include <linux/ctype.h>
55
56#define PFX "ipmi_ssif: "
57#define DEVICE_NAME "ipmi_ssif"
58
59#define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD	0x57
60
61#define	SSIF_IPMI_REQUEST			2
62#define	SSIF_IPMI_MULTI_PART_REQUEST_START	6
63#define	SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE	7
64#define	SSIF_IPMI_RESPONSE			3
65#define	SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE	9
66
67/* ssif_debug is a bit-field
68 *	SSIF_DEBUG_MSG -	commands and their responses
69 *	SSIF_DEBUG_STATES -	message states
70 *	SSIF_DEBUG_TIMING -	 Measure times between events in the driver
71 */
72#define SSIF_DEBUG_TIMING	4
73#define SSIF_DEBUG_STATE	2
74#define SSIF_DEBUG_MSG		1
75#define SSIF_NODEBUG		0
76#define SSIF_DEFAULT_DEBUG	(SSIF_NODEBUG)
77
78/*
79 * Timer values
80 */
81#define SSIF_MSG_USEC		20000	/* 20ms between message tries. */
82#define SSIF_MSG_PART_USEC	5000	/* 5ms for a message part */
83
84/* How many times to we retry sending/receiving the message. */
85#define	SSIF_SEND_RETRIES	5
86#define	SSIF_RECV_RETRIES	250
87
88#define SSIF_MSG_MSEC		(SSIF_MSG_USEC / 1000)
89#define SSIF_MSG_JIFFIES	((SSIF_MSG_USEC * 1000) / TICK_NSEC)
90#define SSIF_MSG_PART_JIFFIES	((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
91
92enum ssif_intf_state {
93	SSIF_NORMAL,
94	SSIF_GETTING_FLAGS,
95	SSIF_GETTING_EVENTS,
96	SSIF_CLEARING_FLAGS,
97	SSIF_GETTING_MESSAGES,
98	/* FIXME - add watchdog stuff. */
99};
100
101#define SSIF_IDLE(ssif)	 ((ssif)->ssif_state == SSIF_NORMAL \
102			  && (ssif)->curr_msg == NULL)
103
104/*
105 * Indexes into stats[] in ssif_info below.
106 */
107enum ssif_stat_indexes {
108	/* Number of total messages sent. */
109	SSIF_STAT_sent_messages = 0,
110
111	/*
112	 * Number of message parts sent.  Messages may be broken into
113	 * parts if they are long.
114	 */
115	SSIF_STAT_sent_messages_parts,
116
117	/*
118	 * Number of time a message was retried.
119	 */
120	SSIF_STAT_send_retries,
121
122	/*
123	 * Number of times the send of a message failed.
124	 */
125	SSIF_STAT_send_errors,
126
127	/*
128	 * Number of message responses received.
129	 */
130	SSIF_STAT_received_messages,
131
132	/*
133	 * Number of message fragments received.
134	 */
135	SSIF_STAT_received_message_parts,
136
137	/*
138	 * Number of times the receive of a message was retried.
139	 */
140	SSIF_STAT_receive_retries,
141
142	/*
143	 * Number of errors receiving messages.
144	 */
145	SSIF_STAT_receive_errors,
146
147	/*
148	 * Number of times a flag fetch was requested.
149	 */
150	SSIF_STAT_flag_fetches,
151
152	/*
153	 * Number of times the hardware didn't follow the state machine.
154	 */
155	SSIF_STAT_hosed,
156
157	/*
158	 * Number of received events.
159	 */
160	SSIF_STAT_events,
161
162	/* Number of asyncronous messages received. */
163	SSIF_STAT_incoming_messages,
164
165	/* Number of watchdog pretimeouts. */
166	SSIF_STAT_watchdog_pretimeouts,
167
168	/* Number of alers received. */
169	SSIF_STAT_alerts,
170
171	/* Always add statistics before this value, it must be last. */
172	SSIF_NUM_STATS
173};
174
175struct ssif_addr_info {
176	unsigned short addr;
177	struct i2c_board_info binfo;
178	char *adapter_name;
179	int debug;
180	int slave_addr;
181	enum ipmi_addr_src addr_src;
182	union ipmi_smi_info_union addr_info;
183
184	struct mutex clients_mutex;
185	struct list_head clients;
186
187	struct list_head link;
188};
189
190struct ssif_info;
191
192typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
193			     unsigned char *data, unsigned int len);
194
195struct ssif_info {
196	ipmi_smi_t          intf;
197	int                 intf_num;
198	spinlock_t	    lock;
199	struct ipmi_smi_msg *waiting_msg;
200	struct ipmi_smi_msg *curr_msg;
201	enum ssif_intf_state ssif_state;
202	unsigned long       ssif_debug;
203
204	struct ipmi_smi_handlers handlers;
205
206	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
207	union ipmi_smi_info_union addr_info;
208
209	/*
210	 * Flags from the last GET_MSG_FLAGS command, used when an ATTN
211	 * is set to hold the flags until we are done handling everything
212	 * from the flags.
213	 */
214#define RECEIVE_MSG_AVAIL	0x01
215#define EVENT_MSG_BUFFER_FULL	0x02
216#define WDT_PRE_TIMEOUT_INT	0x08
217	unsigned char       msg_flags;
218
219	u8		    global_enables;
220	bool		    has_event_buffer;
221	bool		    supports_alert;
222
223	/*
224	 * Used to tell what we should do with alerts.  If we are
225	 * waiting on a response, read the data immediately.
226	 */
227	bool		    got_alert;
228	bool		    waiting_alert;
229
230	/*
231	 * If set to true, this will request events the next time the
232	 * state machine is idle.
233	 */
234	bool                req_events;
235
236	/*
237	 * If set to true, this will request flags the next time the
238	 * state machine is idle.
239	 */
240	bool                req_flags;
241
242	/*
243	 * Used to perform timer operations when run-to-completion
244	 * mode is on.  This is a countdown timer.
245	 */
246	int                 rtc_us_timer;
247
248	/* Used for sending/receiving data.  +1 for the length. */
249	unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
250	unsigned int  data_len;
251
252	/* Temp receive buffer, gets copied into data. */
253	unsigned char recv[I2C_SMBUS_BLOCK_MAX];
254
255	struct i2c_client *client;
256	ssif_i2c_done done_handler;
257
258	/* Thread interface handling */
259	struct task_struct *thread;
260	struct completion wake_thread;
261	bool stopping;
262	int i2c_read_write;
263	int i2c_command;
264	unsigned char *i2c_data;
265	unsigned int i2c_size;
266
267	/* From the device id response. */
268	struct ipmi_device_id device_id;
269
270	struct timer_list retry_timer;
271	int retries_left;
272
273	/* Info from SSIF cmd */
274	unsigned char max_xmit_msg_size;
275	unsigned char max_recv_msg_size;
276	unsigned int  multi_support;
277	int           supports_pec;
278
279#define SSIF_NO_MULTI		0
280#define SSIF_MULTI_2_PART	1
281#define SSIF_MULTI_n_PART	2
282	unsigned char *multi_data;
283	unsigned int  multi_len;
284	unsigned int  multi_pos;
285
286	atomic_t stats[SSIF_NUM_STATS];
287};
288
289#define ssif_inc_stat(ssif, stat) \
290	atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
291#define ssif_get_stat(ssif, stat) \
292	((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
293
294static bool initialized;
295
296static atomic_t next_intf = ATOMIC_INIT(0);
297
298static void return_hosed_msg(struct ssif_info *ssif_info,
299			     struct ipmi_smi_msg *msg);
300static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
301static int start_send(struct ssif_info *ssif_info,
302		      unsigned char   *data,
303		      unsigned int    len);
304
305static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
306					  unsigned long *flags)
307{
308	spin_lock_irqsave(&ssif_info->lock, *flags);
309	return flags;
310}
311
312static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
313				  unsigned long *flags)
314{
315	spin_unlock_irqrestore(&ssif_info->lock, *flags);
316}
317
318static void deliver_recv_msg(struct ssif_info *ssif_info,
319			     struct ipmi_smi_msg *msg)
320{
321	ipmi_smi_t    intf = ssif_info->intf;
322
323	if (!intf) {
324		ipmi_free_smi_msg(msg);
325	} else if (msg->rsp_size < 0) {
326		return_hosed_msg(ssif_info, msg);
327		pr_err(PFX
328		       "Malformed message in deliver_recv_msg: rsp_size = %d\n",
329		       msg->rsp_size);
330	} else {
331		ipmi_smi_msg_received(intf, msg);
332	}
333}
334
335static 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 SSIF_IDLE and start a
352 * new operation, so there is no need to check for new messages to
353 * start in here.
354 */
355static 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, msg, 3) != 0) {
369		/* Error, just go to normal state. */
370		ssif_info->ssif_state = SSIF_NORMAL;
371	}
372}
373
374static 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, mb, 2) != 0)
385		ssif_info->ssif_state = SSIF_NORMAL;
386}
387
388static 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, msg->data, msg->data_size) != 0) {
392		unsigned long oflags;
393
394		flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
395		ssif_info->curr_msg = NULL;
396		ssif_info->ssif_state = SSIF_NORMAL;
397		ipmi_ssif_unlock_cond(ssif_info, flags);
398		ipmi_free_smi_msg(msg);
399	}
400}
401
402static 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_NORMAL;
411		return;
412	}
413
414	ssif_info->curr_msg = msg;
415	ssif_info->ssif_state = SSIF_GETTING_EVENTS;
416	ipmi_ssif_unlock_cond(ssif_info, flags);
417
418	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
419	msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
420	msg->data_size = 2;
421
422	check_start_send(ssif_info, flags, msg);
423}
424
425static void start_recv_msg_fetch(struct ssif_info *ssif_info,
426				 unsigned long *flags)
427{
428	struct ipmi_smi_msg *msg;
429
430	msg = ipmi_alloc_smi_msg();
431	if (!msg) {
432		ssif_info->ssif_state = SSIF_NORMAL;
433		return;
434	}
435
436	ssif_info->curr_msg = msg;
437	ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
438	ipmi_ssif_unlock_cond(ssif_info, flags);
439
440	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
441	msg->data[1] = IPMI_GET_MSG_CMD;
442	msg->data_size = 2;
443
444	check_start_send(ssif_info, flags, msg);
445}
446
447/*
448 * Must be called with the message lock held.  This will release the
449 * message lock.  Note that the caller will check SSIF_IDLE and start a
450 * new operation, so there is no need to check for new messages to
451 * start in here.
452 */
453static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
454{
455	if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
456		ipmi_smi_t intf = ssif_info->intf;
457		/* Watchdog pre-timeout */
458		ssif_inc_stat(ssif_info, watchdog_pretimeouts);
459		start_clear_flags(ssif_info, flags);
460		if (intf)
461			ipmi_smi_watchdog_pretimeout(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_NORMAL;
470		ipmi_ssif_unlock_cond(ssif_info, flags);
471	}
472}
473
474static 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						&ssif_info->wake_thread);
484		if (ssif_info->stopping)
485			break;
486		if (result == -ERESTARTSYS)
487			continue;
488		init_completion(&ssif_info->wake_thread);
489
490		if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
491			result = i2c_smbus_write_block_data(
492				ssif_info->client, ssif_info->i2c_command,
493				ssif_info->i2c_data[0],
494				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				ssif_info->client, ssif_info->i2c_command,
499				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
513static int 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	return 0;
526}
527
528
529static void msg_done_handler(struct ssif_info *ssif_info, int result,
530			     unsigned char *data, unsigned int len);
531
532static void start_get(struct ssif_info *ssif_info)
533{
534	int rv;
535
536	ssif_info->rtc_us_timer = 0;
537	ssif_info->multi_pos = 0;
538
539	rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
540			  SSIF_IPMI_RESPONSE,
541			  ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
542	if (rv < 0) {
543		/* request failed, just return the error. */
544		if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
545			pr_info("Error from i2c_non_blocking_op(5)\n");
546
547		msg_done_handler(ssif_info, -EIO, NULL, 0);
548	}
549}
550
551static void retry_timeout(unsigned long data)
552{
553	struct ssif_info *ssif_info = (void *) data;
554	unsigned long oflags, *flags;
555	bool waiting;
556
557	if (ssif_info->stopping)
558		return;
559
560	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
561	waiting = ssif_info->waiting_alert;
562	ssif_info->waiting_alert = false;
563	ipmi_ssif_unlock_cond(ssif_info, flags);
564
565	if (waiting)
566		start_get(ssif_info);
567}
568
569
570static void ssif_alert(struct i2c_client *client, unsigned int data)
571{
572	struct ssif_info *ssif_info = i2c_get_clientdata(client);
573	unsigned long oflags, *flags;
574	bool do_get = false;
575
576	ssif_inc_stat(ssif_info, alerts);
577
578	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
579	if (ssif_info->waiting_alert) {
580		ssif_info->waiting_alert = false;
581		del_timer(&ssif_info->retry_timer);
582		do_get = true;
583	} else if (ssif_info->curr_msg) {
584		ssif_info->got_alert = true;
585	}
586	ipmi_ssif_unlock_cond(ssif_info, flags);
587	if (do_get)
588		start_get(ssif_info);
589}
590
591static int start_resend(struct ssif_info *ssif_info);
592
593static void msg_done_handler(struct ssif_info *ssif_info, int result,
594			     unsigned char *data, unsigned int len)
595{
596	struct ipmi_smi_msg *msg;
597	unsigned long oflags, *flags;
598	int rv;
599
600	/*
601	 * We are single-threaded here, so no need for a lock until we
602	 * start messing with driver states or the queues.
603	 */
604
605	if (result < 0) {
606		ssif_info->retries_left--;
607		if (ssif_info->retries_left > 0) {
608			ssif_inc_stat(ssif_info, receive_retries);
609
610			flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
611			ssif_info->waiting_alert = true;
612			ssif_info->rtc_us_timer = SSIF_MSG_USEC;
613			mod_timer(&ssif_info->retry_timer,
614				  jiffies + SSIF_MSG_JIFFIES);
615			ipmi_ssif_unlock_cond(ssif_info, flags);
616			return;
617		}
618
619		ssif_inc_stat(ssif_info, receive_errors);
620
621		if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
622			pr_info("Error in msg_done_handler: %d\n", result);
623		len = 0;
624		goto continue_op;
625	}
626
627	if ((len > 1) && (ssif_info->multi_pos == 0)
628				&& (data[0] == 0x00) && (data[1] == 0x01)) {
629		/* Start of multi-part read.  Start the next transaction. */
630		int i;
631
632		ssif_inc_stat(ssif_info, received_message_parts);
633
634		/* Remove the multi-part read marker. */
635		len -= 2;
636		for (i = 0; i < len; i++)
637			ssif_info->data[i] = data[i+2];
638		ssif_info->multi_len = len;
639		ssif_info->multi_pos = 1;
640
641		rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
642				  SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
643				  ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
644		if (rv < 0) {
645			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
646				pr_info("Error from i2c_non_blocking_op(1)\n");
647
648			result = -EIO;
649		} else
650			return;
651	} else if (ssif_info->multi_pos) {
652		/* Middle of multi-part read.  Start the next transaction. */
653		int i;
654		unsigned char blocknum;
655
656		if (len == 0) {
657			result = -EIO;
658			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
659				pr_info(PFX "Middle message with no data\n");
660
661			goto continue_op;
662		}
663
664		blocknum = data[0];
665
666		if (ssif_info->multi_len + len - 1 > IPMI_MAX_MSG_LENGTH) {
667			/* Received message too big, abort the operation. */
668			result = -E2BIG;
669			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
670				pr_info("Received message too big\n");
671
672			goto continue_op;
673		}
674
675		/* Remove the blocknum from the data. */
676		len--;
677		for (i = 0; i < len; i++)
678			ssif_info->data[i + ssif_info->multi_len] = data[i + 1];
679		ssif_info->multi_len += len;
680		if (blocknum == 0xff) {
681			/* End of read */
682			len = ssif_info->multi_len;
683			data = ssif_info->data;
684		} else if (blocknum + 1 != ssif_info->multi_pos) {
685			/*
686			 * Out of sequence block, just abort.  Block
687			 * numbers start at zero for the second block,
688			 * but multi_pos starts at one, so the +1.
689			 */
690			result = -EIO;
691		} else {
692			ssif_inc_stat(ssif_info, received_message_parts);
693
694			ssif_info->multi_pos++;
695
696			rv = ssif_i2c_send(ssif_info, msg_done_handler,
697					   I2C_SMBUS_READ,
698					   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
699					   ssif_info->recv,
700					   I2C_SMBUS_BLOCK_DATA);
701			if (rv < 0) {
702				if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
703					pr_info(PFX
704						"Error from ssif_i2c_send\n");
705
706				result = -EIO;
707			} else
708				return;
709		}
710	}
711
712	if (result < 0) {
713		ssif_inc_stat(ssif_info, receive_errors);
714	} else {
715		ssif_inc_stat(ssif_info, received_messages);
716		ssif_inc_stat(ssif_info, received_message_parts);
717	}
718
719
720 continue_op:
721	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
722		pr_info(PFX "DONE 1: state = %d, result=%d.\n",
723			ssif_info->ssif_state, result);
724
725	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
726	msg = ssif_info->curr_msg;
727	if (msg) {
728		msg->rsp_size = len;
729		if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
730			msg->rsp_size = IPMI_MAX_MSG_LENGTH;
731		memcpy(msg->rsp, data, msg->rsp_size);
732		ssif_info->curr_msg = NULL;
733	}
734
735	switch (ssif_info->ssif_state) {
736	case SSIF_NORMAL:
737		ipmi_ssif_unlock_cond(ssif_info, flags);
738		if (!msg)
739			break;
740
741		if (result < 0)
742			return_hosed_msg(ssif_info, msg);
743		else
744			deliver_recv_msg(ssif_info, msg);
745		break;
746
747	case SSIF_GETTING_FLAGS:
748		/* We got the flags from the SSIF, now handle them. */
749		if ((result < 0) || (len < 4) || (data[2] != 0)) {
750			/*
751			 * Error fetching flags, or invalid length,
752			 * just give up for now.
753			 */
754			ssif_info->ssif_state = SSIF_NORMAL;
755			ipmi_ssif_unlock_cond(ssif_info, flags);
756			pr_warn(PFX "Error getting flags: %d %d, %x\n",
757			       result, len, data[2]);
758		} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
759			   || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
760			pr_warn(PFX "Invalid response getting flags: %x %x\n",
761				data[0], data[1]);
762		} else {
763			ssif_inc_stat(ssif_info, flag_fetches);
764			ssif_info->msg_flags = data[3];
765			handle_flags(ssif_info, flags);
766		}
767		break;
768
769	case SSIF_CLEARING_FLAGS:
770		/* We cleared the flags. */
771		if ((result < 0) || (len < 3) || (data[2] != 0)) {
772			/* Error clearing flags */
773			pr_warn(PFX "Error clearing flags: %d %d, %x\n",
774			       result, len, data[2]);
775		} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
776			   || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
777			pr_warn(PFX "Invalid response clearing flags: %x %x\n",
778				data[0], data[1]);
779		}
780		ssif_info->ssif_state = SSIF_NORMAL;
781		ipmi_ssif_unlock_cond(ssif_info, flags);
782		break;
783
784	case SSIF_GETTING_EVENTS:
785		if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
786			/* Error getting event, probably done. */
787			msg->done(msg);
788
789			/* Take off the event flag. */
790			ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
791			handle_flags(ssif_info, flags);
792		} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
793			   || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
794			pr_warn(PFX "Invalid response getting events: %x %x\n",
795				msg->rsp[0], msg->rsp[1]);
796			msg->done(msg);
797			/* Take off the event flag. */
798			ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
799			handle_flags(ssif_info, flags);
800		} else {
801			handle_flags(ssif_info, flags);
802			ssif_inc_stat(ssif_info, events);
803			deliver_recv_msg(ssif_info, msg);
804		}
805		break;
806
807	case SSIF_GETTING_MESSAGES:
808		if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
809			/* Error getting event, probably done. */
810			msg->done(msg);
811
812			/* Take off the msg flag. */
813			ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
814			handle_flags(ssif_info, flags);
815		} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
816			   || msg->rsp[1] != IPMI_GET_MSG_CMD) {
817			pr_warn(PFX "Invalid response clearing flags: %x %x\n",
818				msg->rsp[0], msg->rsp[1]);
819			msg->done(msg);
820
821			/* Take off the msg flag. */
822			ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
823			handle_flags(ssif_info, flags);
824		} else {
825			ssif_inc_stat(ssif_info, incoming_messages);
826			handle_flags(ssif_info, flags);
827			deliver_recv_msg(ssif_info, msg);
828		}
829		break;
830	}
831
832	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
833	if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
834		if (ssif_info->req_events)
835			start_event_fetch(ssif_info, flags);
836		else if (ssif_info->req_flags)
837			start_flag_fetch(ssif_info, flags);
838		else
839			start_next_msg(ssif_info, flags);
840	} else
841		ipmi_ssif_unlock_cond(ssif_info, flags);
842
843	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
844		pr_info(PFX "DONE 2: state = %d.\n", ssif_info->ssif_state);
845}
846
847static void msg_written_handler(struct ssif_info *ssif_info, int result,
848				unsigned char *data, unsigned int len)
849{
850	int rv;
851
852	/* We are single-threaded here, so no need for a lock. */
853	if (result < 0) {
854		ssif_info->retries_left--;
855		if (ssif_info->retries_left > 0) {
856			if (!start_resend(ssif_info)) {
857				ssif_inc_stat(ssif_info, send_retries);
858				return;
859			}
860			/* request failed, just return the error. */
861			ssif_inc_stat(ssif_info, send_errors);
862
863			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
864				pr_info(PFX
865					"Out of retries in msg_written_handler\n");
866			msg_done_handler(ssif_info, -EIO, NULL, 0);
867			return;
868		}
869
870		ssif_inc_stat(ssif_info, send_errors);
871
872		/*
873		 * Got an error on transmit, let the done routine
874		 * handle it.
875		 */
876		if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
877			pr_info("Error in msg_written_handler: %d\n", result);
878
879		msg_done_handler(ssif_info, result, NULL, 0);
880		return;
881	}
882
883	if (ssif_info->multi_data) {
884		/*
885		 * In the middle of a multi-data write.  See the comment
886		 * in the SSIF_MULTI_n_PART case in the probe function
887		 * for details on the intricacies of this.
888		 */
889		int left;
890
891		ssif_inc_stat(ssif_info, sent_messages_parts);
892
893		left = ssif_info->multi_len - ssif_info->multi_pos;
894		if (left > 32)
895			left = 32;
896		/* Length byte. */
897		ssif_info->multi_data[ssif_info->multi_pos] = left;
898		ssif_info->multi_pos += left;
899		if (left < 32)
900			/*
901			 * Write is finished.  Note that we must end
902			 * with a write of less than 32 bytes to
903			 * complete the transaction, even if it is
904			 * zero bytes.
905			 */
906			ssif_info->multi_data = NULL;
907
908		rv = ssif_i2c_send(ssif_info, msg_written_handler,
909				  I2C_SMBUS_WRITE,
910				  SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
911				  ssif_info->multi_data + ssif_info->multi_pos,
912				  I2C_SMBUS_BLOCK_DATA);
913		if (rv < 0) {
914			/* request failed, just return the error. */
915			ssif_inc_stat(ssif_info, send_errors);
916
917			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
918				pr_info("Error from i2c_non_blocking_op(3)\n");
919			msg_done_handler(ssif_info, -EIO, NULL, 0);
920		}
921	} else {
922		unsigned long oflags, *flags;
923		bool got_alert;
924
925		ssif_inc_stat(ssif_info, sent_messages);
926		ssif_inc_stat(ssif_info, sent_messages_parts);
927
928		flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
929		got_alert = ssif_info->got_alert;
930		if (got_alert) {
931			ssif_info->got_alert = false;
932			ssif_info->waiting_alert = false;
933		}
934
935		if (got_alert) {
936			ipmi_ssif_unlock_cond(ssif_info, flags);
937			/* The alert already happened, try now. */
938			retry_timeout((unsigned long) ssif_info);
939		} else {
940			/* Wait a jiffie then request the next message */
941			ssif_info->waiting_alert = true;
942			ssif_info->retries_left = SSIF_RECV_RETRIES;
943			ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
944			mod_timer(&ssif_info->retry_timer,
945				  jiffies + SSIF_MSG_PART_JIFFIES);
946			ipmi_ssif_unlock_cond(ssif_info, flags);
947		}
948	}
949}
950
951static int start_resend(struct ssif_info *ssif_info)
952{
953	int rv;
954	int command;
955
956	ssif_info->got_alert = false;
957
958	if (ssif_info->data_len > 32) {
959		command = SSIF_IPMI_MULTI_PART_REQUEST_START;
960		ssif_info->multi_data = ssif_info->data;
961		ssif_info->multi_len = ssif_info->data_len;
962		/*
963		 * Subtle thing, this is 32, not 33, because we will
964		 * overwrite the thing at position 32 (which was just
965		 * transmitted) with the new length.
966		 */
967		ssif_info->multi_pos = 32;
968		ssif_info->data[0] = 32;
969	} else {
970		ssif_info->multi_data = NULL;
971		command = SSIF_IPMI_REQUEST;
972		ssif_info->data[0] = ssif_info->data_len;
973	}
974
975	rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
976			  command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
977	if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
978		pr_info("Error from i2c_non_blocking_op(4)\n");
979	return rv;
980}
981
982static int start_send(struct ssif_info *ssif_info,
983		      unsigned char   *data,
984		      unsigned int    len)
985{
986	if (len > IPMI_MAX_MSG_LENGTH)
987		return -E2BIG;
988	if (len > ssif_info->max_xmit_msg_size)
989		return -E2BIG;
990
991	ssif_info->retries_left = SSIF_SEND_RETRIES;
992	memcpy(ssif_info->data + 1, data, len);
993	ssif_info->data_len = len;
994	return start_resend(ssif_info);
995}
996
997/* Must be called with the message lock held. */
998static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
999{
1000	struct ipmi_smi_msg *msg;
1001	unsigned long oflags;
1002
1003 restart:
1004	if (!SSIF_IDLE(ssif_info)) {
1005		ipmi_ssif_unlock_cond(ssif_info, flags);
1006		return;
1007	}
1008
1009	if (!ssif_info->waiting_msg) {
1010		ssif_info->curr_msg = NULL;
1011		ipmi_ssif_unlock_cond(ssif_info, flags);
1012	} else {
1013		int rv;
1014
1015		ssif_info->curr_msg = ssif_info->waiting_msg;
1016		ssif_info->waiting_msg = NULL;
1017		ipmi_ssif_unlock_cond(ssif_info, flags);
1018		rv = start_send(ssif_info,
1019				ssif_info->curr_msg->data,
1020				ssif_info->curr_msg->data_size);
1021		if (rv) {
1022			msg = ssif_info->curr_msg;
1023			ssif_info->curr_msg = NULL;
1024			return_hosed_msg(ssif_info, msg);
1025			flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1026			goto restart;
1027		}
1028	}
1029}
1030
1031static void sender(void                *send_info,
1032		   struct ipmi_smi_msg *msg)
1033{
1034	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1035	unsigned long oflags, *flags;
1036
1037	BUG_ON(ssif_info->waiting_msg);
1038	ssif_info->waiting_msg = msg;
1039
1040	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1041	start_next_msg(ssif_info, flags);
1042
1043	if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1044		struct timeval t;
1045
1046		do_gettimeofday(&t);
1047		pr_info("**Enqueue %02x %02x: %ld.%6.6ld\n",
1048		       msg->data[0], msg->data[1],
1049		       (long) t.tv_sec, (long) t.tv_usec);
1050	}
1051}
1052
1053static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1054{
1055	struct ssif_info *ssif_info = send_info;
1056
1057	data->addr_src = ssif_info->addr_source;
1058	data->dev = &ssif_info->client->dev;
1059	data->addr_info = ssif_info->addr_info;
1060	get_device(data->dev);
1061
1062	return 0;
1063}
1064
1065/*
1066 * Instead of having our own timer to periodically check the message
1067 * flags, we let the message handler drive us.
1068 */
1069static void request_events(void *send_info)
1070{
1071	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1072	unsigned long oflags, *flags;
1073
1074	if (!ssif_info->has_event_buffer)
1075		return;
1076
1077	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1078	/*
1079	 * Request flags first, not events, because the lower layer
1080	 * doesn't have a way to send an attention.  But make sure
1081	 * event checking still happens.
1082	 */
1083	ssif_info->req_events = true;
1084	if (SSIF_IDLE(ssif_info))
1085		start_flag_fetch(ssif_info, flags);
1086	else {
1087		ssif_info->req_flags = true;
1088		ipmi_ssif_unlock_cond(ssif_info, flags);
1089	}
1090}
1091
1092static int inc_usecount(void *send_info)
1093{
1094	struct ssif_info *ssif_info = send_info;
1095
1096	if (!i2c_get_adapter(ssif_info->client->adapter->nr))
1097		return -ENODEV;
1098
1099	i2c_use_client(ssif_info->client);
1100	return 0;
1101}
1102
1103static void dec_usecount(void *send_info)
1104{
1105	struct ssif_info *ssif_info = send_info;
1106
1107	i2c_release_client(ssif_info->client);
1108	i2c_put_adapter(ssif_info->client->adapter);
1109}
1110
1111static int ssif_start_processing(void *send_info,
1112				 ipmi_smi_t intf)
1113{
1114	struct ssif_info *ssif_info = send_info;
1115
1116	ssif_info->intf = intf;
1117
1118	return 0;
1119}
1120
1121#define MAX_SSIF_BMCS 4
1122
1123static unsigned short addr[MAX_SSIF_BMCS];
1124static int num_addrs;
1125module_param_array(addr, ushort, &num_addrs, 0);
1126MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1127
1128static char *adapter_name[MAX_SSIF_BMCS];
1129static int num_adapter_names;
1130module_param_array(adapter_name, charp, &num_adapter_names, 0);
1131MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1132
1133static int slave_addrs[MAX_SSIF_BMCS];
1134static int num_slave_addrs;
1135module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1136MODULE_PARM_DESC(slave_addrs,
1137		 "The default IPMB slave address for the controller.");
1138
1139/*
1140 * Bit 0 enables message debugging, bit 1 enables state debugging, and
1141 * bit 2 enables timing debugging.  This is an array indexed by
1142 * interface number"
1143 */
1144static int dbg[MAX_SSIF_BMCS];
1145static int num_dbg;
1146module_param_array(dbg, int, &num_dbg, 0);
1147MODULE_PARM_DESC(dbg, "Turn on debugging.");
1148
1149static bool ssif_dbg_probe;
1150module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1151MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1152
1153static int use_thread;
1154module_param(use_thread, int, 0);
1155MODULE_PARM_DESC(use_thread, "Use the thread interface.");
1156
1157static bool ssif_tryacpi = 1;
1158module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1159MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1160
1161static bool ssif_trydmi = 1;
1162module_param_named(trydmi, ssif_trydmi, bool, 0);
1163MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1164
1165static DEFINE_MUTEX(ssif_infos_mutex);
1166static LIST_HEAD(ssif_infos);
1167
1168static int ssif_remove(struct i2c_client *client)
1169{
1170	struct ssif_info *ssif_info = i2c_get_clientdata(client);
1171	int rv;
1172
1173	if (!ssif_info)
1174		return 0;
1175
1176	/*
1177	 * After this point, we won't deliver anything asychronously
1178	 * to the message handler.  We can unregister ourself.
1179	 */
1180	rv = ipmi_unregister_smi(ssif_info->intf);
1181	if (rv) {
1182		pr_err(PFX "Unable to unregister device: errno=%d\n", rv);
1183		return rv;
1184	}
1185	ssif_info->intf = NULL;
1186
1187	/* make sure the driver is not looking for flags any more. */
1188	while (ssif_info->ssif_state != SSIF_NORMAL)
1189		schedule_timeout(1);
1190
1191	ssif_info->stopping = true;
1192	del_timer_sync(&ssif_info->retry_timer);
1193	if (ssif_info->thread) {
1194		complete(&ssif_info->wake_thread);
1195		kthread_stop(ssif_info->thread);
1196	}
1197
1198	/*
1199	 * No message can be outstanding now, we have removed the
1200	 * upper layer and it permitted us to do so.
1201	 */
1202	kfree(ssif_info);
1203	return 0;
1204}
1205
1206static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1207		  int *resp_len, unsigned char *resp)
1208{
1209	int retry_cnt;
1210	int ret;
1211
1212	retry_cnt = SSIF_SEND_RETRIES;
1213 retry1:
1214	ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1215	if (ret) {
1216		retry_cnt--;
1217		if (retry_cnt > 0)
1218			goto retry1;
1219		return -ENODEV;
1220	}
1221
1222	ret = -ENODEV;
1223	retry_cnt = SSIF_RECV_RETRIES;
1224	while (retry_cnt > 0) {
1225		ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1226						resp);
1227		if (ret > 0)
1228			break;
1229		msleep(SSIF_MSG_MSEC);
1230		retry_cnt--;
1231		if (retry_cnt <= 0)
1232			break;
1233	}
1234
1235	if (ret > 0) {
1236		/* Validate that the response is correct. */
1237		if (ret < 3 ||
1238		    (resp[0] != (msg[0] | (1 << 2))) ||
1239		    (resp[1] != msg[1]))
1240			ret = -EINVAL;
1241		else {
1242			*resp_len = ret;
1243			ret = 0;
1244		}
1245	}
1246
1247	return ret;
1248}
1249
1250static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1251{
1252	unsigned char *resp;
1253	unsigned char msg[3];
1254	int           rv;
1255	int           len;
1256
1257	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1258	if (!resp)
1259		return -ENOMEM;
1260
1261	/* Do a Get Device ID command, since it is required. */
1262	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1263	msg[1] = IPMI_GET_DEVICE_ID_CMD;
1264	rv = do_cmd(client, 2, msg, &len, resp);
1265	if (rv)
1266		rv = -ENODEV;
1267	else
1268		strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1269	kfree(resp);
1270	return rv;
1271}
1272
1273static int smi_type_proc_show(struct seq_file *m, void *v)
1274{
1275	seq_puts(m, "ssif\n");
1276
1277	return 0;
1278}
1279
1280static int smi_type_proc_open(struct inode *inode, struct file *file)
1281{
1282	return single_open(file, smi_type_proc_show, inode->i_private);
1283}
1284
1285static const struct file_operations smi_type_proc_ops = {
1286	.open		= smi_type_proc_open,
1287	.read		= seq_read,
1288	.llseek		= seq_lseek,
1289	.release	= single_release,
1290};
1291
1292static int smi_stats_proc_show(struct seq_file *m, void *v)
1293{
1294	struct ssif_info *ssif_info = m->private;
1295
1296	seq_printf(m, "sent_messages:          %u\n",
1297		   ssif_get_stat(ssif_info, sent_messages));
1298	seq_printf(m, "sent_messages_parts:    %u\n",
1299		   ssif_get_stat(ssif_info, sent_messages_parts));
1300	seq_printf(m, "send_retries:           %u\n",
1301		   ssif_get_stat(ssif_info, send_retries));
1302	seq_printf(m, "send_errors:            %u\n",
1303		   ssif_get_stat(ssif_info, send_errors));
1304	seq_printf(m, "received_messages:      %u\n",
1305		   ssif_get_stat(ssif_info, received_messages));
1306	seq_printf(m, "received_message_parts: %u\n",
1307		   ssif_get_stat(ssif_info, received_message_parts));
1308	seq_printf(m, "receive_retries:        %u\n",
1309		   ssif_get_stat(ssif_info, receive_retries));
1310	seq_printf(m, "receive_errors:         %u\n",
1311		   ssif_get_stat(ssif_info, receive_errors));
1312	seq_printf(m, "flag_fetches:           %u\n",
1313		   ssif_get_stat(ssif_info, flag_fetches));
1314	seq_printf(m, "hosed:                  %u\n",
1315		   ssif_get_stat(ssif_info, hosed));
1316	seq_printf(m, "events:                 %u\n",
1317		   ssif_get_stat(ssif_info, events));
1318	seq_printf(m, "watchdog_pretimeouts:   %u\n",
1319		   ssif_get_stat(ssif_info, watchdog_pretimeouts));
1320	seq_printf(m, "alerts:                 %u\n",
1321		   ssif_get_stat(ssif_info, alerts));
1322	return 0;
1323}
1324
1325static int smi_stats_proc_open(struct inode *inode, struct file *file)
1326{
1327	return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
1328}
1329
1330static const struct file_operations smi_stats_proc_ops = {
1331	.open		= smi_stats_proc_open,
1332	.read		= seq_read,
1333	.llseek		= seq_lseek,
1334	.release	= single_release,
1335};
1336
1337static int strcmp_nospace(char *s1, char *s2)
1338{
1339	while (*s1 && *s2) {
1340		while (isspace(*s1))
1341			s1++;
1342		while (isspace(*s2))
1343			s2++;
1344		if (*s1 > *s2)
1345			return 1;
1346		if (*s1 < *s2)
1347			return -1;
1348		s1++;
1349		s2++;
1350	}
1351	return 0;
1352}
1353
1354static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1355					     char *adapter_name,
1356					     bool match_null_name)
1357{
1358	struct ssif_addr_info *info, *found = NULL;
1359
1360restart:
1361	list_for_each_entry(info, &ssif_infos, link) {
1362		if (info->binfo.addr == addr) {
1363			if (info->adapter_name || adapter_name) {
1364				if (!info->adapter_name != !adapter_name) {
1365					/* One is NULL and one is not */
1366					continue;
1367				}
1368				if (adapter_name &&
1369				    strcmp_nospace(info->adapter_name,
1370						   adapter_name))
1371					/* Names do not match */
1372					continue;
1373			}
1374			found = info;
1375			break;
1376		}
1377	}
1378
1379	if (!found && match_null_name) {
1380		/* Try to get an exact match first, then try with a NULL name */
1381		adapter_name = NULL;
1382		match_null_name = false;
1383		goto restart;
1384	}
1385
1386	return found;
1387}
1388
1389static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1390{
1391#ifdef CONFIG_ACPI
1392	acpi_handle acpi_handle;
1393
1394	acpi_handle = ACPI_HANDLE(dev);
1395	if (acpi_handle) {
1396		ssif_info->addr_source = SI_ACPI;
1397		ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1398		return true;
1399	}
1400#endif
1401	return false;
1402}
1403
1404/*
1405 * Global enables we care about.
1406 */
1407#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1408			     IPMI_BMC_EVT_MSG_INTR)
1409
1410static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1411{
1412	unsigned char     msg[3];
1413	unsigned char     *resp;
1414	struct ssif_info   *ssif_info;
1415	int               rv = 0;
1416	int               len;
1417	int               i;
1418	u8		  slave_addr = 0;
1419	struct ssif_addr_info *addr_info = NULL;
1420
1421
1422	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1423	if (!resp)
1424		return -ENOMEM;
1425
1426	ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1427	if (!ssif_info) {
1428		kfree(resp);
1429		return -ENOMEM;
1430	}
1431
1432	if (!check_acpi(ssif_info, &client->dev)) {
1433		addr_info = ssif_info_find(client->addr, client->adapter->name,
1434					   true);
1435		if (!addr_info) {
1436			/* Must have come in through sysfs. */
1437			ssif_info->addr_source = SI_HOTMOD;
1438		} else {
1439			ssif_info->addr_source = addr_info->addr_src;
1440			ssif_info->ssif_debug = addr_info->debug;
1441			ssif_info->addr_info = addr_info->addr_info;
1442			slave_addr = addr_info->slave_addr;
1443		}
1444	}
1445
1446	pr_info(PFX "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1447	       ipmi_addr_src_to_str(ssif_info->addr_source),
1448	       client->addr, client->adapter->name, slave_addr);
1449
1450	/*
1451	 * Do a Get Device ID command, since it comes back with some
1452	 * useful info.
1453	 */
1454	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1455	msg[1] = IPMI_GET_DEVICE_ID_CMD;
1456	rv = do_cmd(client, 2, msg, &len, resp);
1457	if (rv)
1458		goto out;
1459
1460	rv = ipmi_demangle_device_id(resp, len, &ssif_info->device_id);
1461	if (rv)
1462		goto out;
1463
1464	ssif_info->client = client;
1465	i2c_set_clientdata(client, ssif_info);
1466
1467	/* Now check for system interface capabilities */
1468	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1469	msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1470	msg[2] = 0; /* SSIF */
1471	rv = do_cmd(client, 3, msg, &len, resp);
1472	if (!rv && (len >= 3) && (resp[2] == 0)) {
1473		if (len < 7) {
1474			if (ssif_dbg_probe)
1475				pr_info(PFX "SSIF info too short: %d\n", len);
1476			goto no_support;
1477		}
1478
1479		/* Got a good SSIF response, handle it. */
1480		ssif_info->max_xmit_msg_size = resp[5];
1481		ssif_info->max_recv_msg_size = resp[6];
1482		ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1483		ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1484
1485		/* Sanitize the data */
1486		switch (ssif_info->multi_support) {
1487		case SSIF_NO_MULTI:
1488			if (ssif_info->max_xmit_msg_size > 32)
1489				ssif_info->max_xmit_msg_size = 32;
1490			if (ssif_info->max_recv_msg_size > 32)
1491				ssif_info->max_recv_msg_size = 32;
1492			break;
1493
1494		case SSIF_MULTI_2_PART:
1495			if (ssif_info->max_xmit_msg_size > 63)
1496				ssif_info->max_xmit_msg_size = 63;
1497			if (ssif_info->max_recv_msg_size > 62)
1498				ssif_info->max_recv_msg_size = 62;
1499			break;
1500
1501		case SSIF_MULTI_n_PART:
1502			/*
1503			 * The specification is rather confusing at
1504			 * this point, but I think I understand what
1505			 * is meant.  At least I have a workable
1506			 * solution.  With multi-part messages, you
1507			 * cannot send a message that is a multiple of
1508			 * 32-bytes in length, because the start and
1509			 * middle messages are 32-bytes and the end
1510			 * message must be at least one byte.  You
1511			 * can't fudge on an extra byte, that would
1512			 * screw up things like fru data writes.  So
1513			 * we limit the length to 63 bytes.  That way
1514			 * a 32-byte message gets sent as a single
1515			 * part.  A larger message will be a 32-byte
1516			 * start and the next message is always going
1517			 * to be 1-31 bytes in length.  Not ideal, but
1518			 * it should work.
1519			 */
1520			if (ssif_info->max_xmit_msg_size > 63)
1521				ssif_info->max_xmit_msg_size = 63;
1522			break;
1523
1524		default:
1525			/* Data is not sane, just give up. */
1526			goto no_support;
1527		}
1528	} else {
1529 no_support:
1530		/* Assume no multi-part or PEC support */
1531		pr_info(PFX "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1532		       rv, len, resp[2]);
1533
1534		ssif_info->max_xmit_msg_size = 32;
1535		ssif_info->max_recv_msg_size = 32;
1536		ssif_info->multi_support = SSIF_NO_MULTI;
1537		ssif_info->supports_pec = 0;
1538	}
1539
1540	/* Make sure the NMI timeout is cleared. */
1541	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1542	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1543	msg[2] = WDT_PRE_TIMEOUT_INT;
1544	rv = do_cmd(client, 3, msg, &len, resp);
1545	if (rv || (len < 3) || (resp[2] != 0))
1546		pr_warn(PFX "Unable to clear message flags: %d %d %2.2x\n",
1547			rv, len, resp[2]);
1548
1549	/* Attempt to enable the event buffer. */
1550	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1551	msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1552	rv = do_cmd(client, 2, msg, &len, resp);
1553	if (rv || (len < 4) || (resp[2] != 0)) {
1554		pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
1555			rv, len, resp[2]);
1556		rv = 0; /* Not fatal */
1557		goto found;
1558	}
1559
1560	ssif_info->global_enables = resp[3];
1561
1562	if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1563		ssif_info->has_event_buffer = true;
1564		/* buffer is already enabled, nothing to do. */
1565		goto found;
1566	}
1567
1568	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1569	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1570	msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1571	rv = do_cmd(client, 3, msg, &len, resp);
1572	if (rv || (len < 2)) {
1573		pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1574			rv, len, resp[2]);
1575		rv = 0; /* Not fatal */
1576		goto found;
1577	}
1578
1579	if (resp[2] == 0) {
1580		/* A successful return means the event buffer is supported. */
1581		ssif_info->has_event_buffer = true;
1582		ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1583	}
1584
1585	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1586	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1587	msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1588	rv = do_cmd(client, 3, msg, &len, resp);
1589	if (rv || (len < 2)) {
1590		pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1591			rv, len, resp[2]);
1592		rv = 0; /* Not fatal */
1593		goto found;
1594	}
1595
1596	if (resp[2] == 0) {
1597		/* A successful return means the alert is supported. */
1598		ssif_info->supports_alert = true;
1599		ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1600	}
1601
1602 found:
1603	ssif_info->intf_num = atomic_inc_return(&next_intf);
1604
1605	if (ssif_dbg_probe) {
1606		pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
1607			client->addr);
1608	}
1609
1610	spin_lock_init(&ssif_info->lock);
1611	ssif_info->ssif_state = SSIF_NORMAL;
1612	init_timer(&ssif_info->retry_timer);
1613	ssif_info->retry_timer.data = (unsigned long) ssif_info;
1614	ssif_info->retry_timer.function = retry_timeout;
1615
1616	for (i = 0; i < SSIF_NUM_STATS; i++)
1617		atomic_set(&ssif_info->stats[i], 0);
1618
1619	if (ssif_info->supports_pec)
1620		ssif_info->client->flags |= I2C_CLIENT_PEC;
1621
1622	ssif_info->handlers.owner = THIS_MODULE;
1623	ssif_info->handlers.start_processing = ssif_start_processing;
1624	ssif_info->handlers.get_smi_info = get_smi_info;
1625	ssif_info->handlers.sender = sender;
1626	ssif_info->handlers.request_events = request_events;
1627	ssif_info->handlers.inc_usecount = inc_usecount;
1628	ssif_info->handlers.dec_usecount = dec_usecount;
1629
1630	{
1631		unsigned int thread_num;
1632
1633		thread_num = ((ssif_info->client->adapter->nr << 8) |
1634			      ssif_info->client->addr);
1635		init_completion(&ssif_info->wake_thread);
1636		ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1637					       "kssif%4.4x", thread_num);
1638		if (IS_ERR(ssif_info->thread)) {
1639			rv = PTR_ERR(ssif_info->thread);
1640			dev_notice(&ssif_info->client->dev,
1641				   "Could not start kernel thread: error %d\n",
1642				   rv);
1643			goto out;
1644		}
1645	}
1646
1647	rv = ipmi_register_smi(&ssif_info->handlers,
1648			       ssif_info,
1649			       &ssif_info->device_id,
1650			       &ssif_info->client->dev,
1651			       slave_addr);
1652	 if (rv) {
1653		pr_err(PFX "Unable to register device: error %d\n", rv);
1654		goto out;
1655	}
1656
1657	rv = ipmi_smi_add_proc_entry(ssif_info->intf, "type",
1658				     &smi_type_proc_ops,
1659				     ssif_info);
1660	if (rv) {
1661		pr_err(PFX "Unable to create proc entry: %d\n", rv);
1662		goto out_err_unreg;
1663	}
1664
1665	rv = ipmi_smi_add_proc_entry(ssif_info->intf, "ssif_stats",
1666				     &smi_stats_proc_ops,
1667				     ssif_info);
1668	if (rv) {
1669		pr_err(PFX "Unable to create proc entry: %d\n", rv);
1670		goto out_err_unreg;
1671	}
1672
1673 out:
1674	if (rv)
1675		kfree(ssif_info);
1676	kfree(resp);
1677	return rv;
1678
1679 out_err_unreg:
1680	ipmi_unregister_smi(ssif_info->intf);
1681	goto out;
1682}
1683
1684static int ssif_adapter_handler(struct device *adev, void *opaque)
1685{
1686	struct ssif_addr_info *addr_info = opaque;
1687
1688	if (adev->type != &i2c_adapter_type)
1689		return 0;
1690
1691	i2c_new_device(to_i2c_adapter(adev), &addr_info->binfo);
1692
1693	if (!addr_info->adapter_name)
1694		return 1; /* Only try the first I2C adapter by default. */
1695	return 0;
1696}
1697
1698static int new_ssif_client(int addr, char *adapter_name,
1699			   int debug, int slave_addr,
1700			   enum ipmi_addr_src addr_src)
1701{
1702	struct ssif_addr_info *addr_info;
1703	int rv = 0;
1704
1705	mutex_lock(&ssif_infos_mutex);
1706	if (ssif_info_find(addr, adapter_name, false)) {
1707		rv = -EEXIST;
1708		goto out_unlock;
1709	}
1710
1711	addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1712	if (!addr_info) {
1713		rv = -ENOMEM;
1714		goto out_unlock;
1715	}
1716
1717	if (adapter_name) {
1718		addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1719		if (!addr_info->adapter_name) {
1720			kfree(addr_info);
1721			rv = -ENOMEM;
1722			goto out_unlock;
1723		}
1724	}
1725
1726	strncpy(addr_info->binfo.type, DEVICE_NAME,
1727		sizeof(addr_info->binfo.type));
1728	addr_info->binfo.addr = addr;
1729	addr_info->binfo.platform_data = addr_info;
1730	addr_info->debug = debug;
1731	addr_info->slave_addr = slave_addr;
1732	addr_info->addr_src = addr_src;
1733
1734	list_add_tail(&addr_info->link, &ssif_infos);
1735
1736	if (initialized)
1737		i2c_for_each_dev(addr_info, ssif_adapter_handler);
1738	/* Otherwise address list will get it */
1739
1740out_unlock:
1741	mutex_unlock(&ssif_infos_mutex);
1742	return rv;
1743}
1744
1745static void free_ssif_clients(void)
1746{
1747	struct ssif_addr_info *info, *tmp;
1748
1749	mutex_lock(&ssif_infos_mutex);
1750	list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1751		list_del(&info->link);
1752		kfree(info->adapter_name);
1753		kfree(info);
1754	}
1755	mutex_unlock(&ssif_infos_mutex);
1756}
1757
1758static unsigned short *ssif_address_list(void)
1759{
1760	struct ssif_addr_info *info;
1761	unsigned int count = 0, i;
1762	unsigned short *address_list;
1763
1764	list_for_each_entry(info, &ssif_infos, link)
1765		count++;
1766
1767	address_list = kzalloc(sizeof(*address_list) * (count + 1), GFP_KERNEL);
1768	if (!address_list)
1769		return NULL;
1770
1771	i = 0;
1772	list_for_each_entry(info, &ssif_infos, link) {
1773		unsigned short addr = info->binfo.addr;
1774		int j;
1775
1776		for (j = 0; j < i; j++) {
1777			if (address_list[j] == addr)
1778				goto skip_addr;
1779		}
1780		address_list[i] = addr;
1781skip_addr:
1782		i++;
1783	}
1784	address_list[i] = I2C_CLIENT_END;
1785
1786	return address_list;
1787}
1788
1789#ifdef CONFIG_ACPI
1790static struct acpi_device_id ssif_acpi_match[] = {
1791	{ "IPI0001", 0 },
1792	{ },
1793};
1794MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1795
1796/*
1797 * Once we get an ACPI failure, we don't try any more, because we go
1798 * through the tables sequentially.  Once we don't find a table, there
1799 * are no more.
1800 */
1801static int acpi_failure;
1802
1803/*
1804 * Defined in the IPMI 2.0 spec.
1805 */
1806struct SPMITable {
1807	s8	Signature[4];
1808	u32	Length;
1809	u8	Revision;
1810	u8	Checksum;
1811	s8	OEMID[6];
1812	s8	OEMTableID[8];
1813	s8	OEMRevision[4];
1814	s8	CreatorID[4];
1815	s8	CreatorRevision[4];
1816	u8	InterfaceType;
1817	u8	IPMIlegacy;
1818	s16	SpecificationRevision;
1819
1820	/*
1821	 * Bit 0 - SCI interrupt supported
1822	 * Bit 1 - I/O APIC/SAPIC
1823	 */
1824	u8	InterruptType;
1825
1826	/*
1827	 * If bit 0 of InterruptType is set, then this is the SCI
1828	 * interrupt in the GPEx_STS register.
1829	 */
1830	u8	GPE;
1831
1832	s16	Reserved;
1833
1834	/*
1835	 * If bit 1 of InterruptType is set, then this is the I/O
1836	 * APIC/SAPIC interrupt.
1837	 */
1838	u32	GlobalSystemInterrupt;
1839
1840	/* The actual register address. */
1841	struct acpi_generic_address addr;
1842
1843	u8	UID[4];
1844
1845	s8      spmi_id[1]; /* A '\0' terminated array starts here. */
1846};
1847
1848static int try_init_spmi(struct SPMITable *spmi)
1849{
1850	unsigned short myaddr;
1851
1852	if (num_addrs >= MAX_SSIF_BMCS)
1853		return -1;
1854
1855	if (spmi->IPMIlegacy != 1) {
1856		pr_warn("IPMI: Bad SPMI legacy: %d\n", spmi->IPMIlegacy);
1857		return -ENODEV;
1858	}
1859
1860	if (spmi->InterfaceType != 4)
1861		return -ENODEV;
1862
1863	if (spmi->addr.space_id != ACPI_ADR_SPACE_SMBUS) {
1864		pr_warn(PFX "Invalid ACPI SSIF I/O Address type: %d\n",
1865			spmi->addr.space_id);
1866		return -EIO;
1867	}
1868
1869	myaddr = spmi->addr.address >> 1;
1870
1871	return new_ssif_client(myaddr, NULL, 0, 0, SI_SPMI);
1872}
1873
1874static void spmi_find_bmc(void)
1875{
1876	acpi_status      status;
1877	struct SPMITable *spmi;
1878	int              i;
1879
1880	if (acpi_disabled)
1881		return;
1882
1883	if (acpi_failure)
1884		return;
1885
1886	for (i = 0; ; i++) {
1887		status = acpi_get_table(ACPI_SIG_SPMI, i+1,
1888					(struct acpi_table_header **)&spmi);
1889		if (status != AE_OK)
1890			return;
1891
1892		try_init_spmi(spmi);
1893	}
1894}
1895#else
1896static void spmi_find_bmc(void) { }
1897#endif
1898
1899#ifdef CONFIG_DMI
1900static int decode_dmi(const struct dmi_device *dmi_dev)
1901{
1902	struct dmi_header *dm = dmi_dev->device_data;
1903	u8             *data = (u8 *) dm;
1904	u8             len = dm->length;
1905	unsigned short myaddr;
1906	int            slave_addr;
1907
1908	if (num_addrs >= MAX_SSIF_BMCS)
1909		return -1;
1910
1911	if (len < 9)
1912		return -1;
1913
1914	if (data[0x04] != 4) /* Not SSIF */
1915		return -1;
1916
1917	if ((data[8] >> 1) == 0) {
1918		/*
1919		 * Some broken systems put the I2C address in
1920		 * the slave address field.  We try to
1921		 * accommodate them here.
1922		 */
1923		myaddr = data[6] >> 1;
1924		slave_addr = 0;
1925	} else {
1926		myaddr = data[8] >> 1;
1927		slave_addr = data[6];
1928	}
1929
1930	return new_ssif_client(myaddr, NULL, 0, 0, SI_SMBIOS);
1931}
1932
1933static void dmi_iterator(void)
1934{
1935	const struct dmi_device *dev = NULL;
1936
1937	while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
1938		decode_dmi(dev);
1939}
1940#else
1941static void dmi_iterator(void) { }
1942#endif
1943
1944static const struct i2c_device_id ssif_id[] = {
1945	{ DEVICE_NAME, 0 },
1946	{ }
1947};
1948MODULE_DEVICE_TABLE(i2c, ssif_id);
1949
1950static struct i2c_driver ssif_i2c_driver = {
1951	.class		= I2C_CLASS_HWMON,
1952	.driver		= {
1953		.owner			= THIS_MODULE,
1954		.name			= DEVICE_NAME
1955	},
1956	.probe		= ssif_probe,
1957	.remove		= ssif_remove,
1958	.alert		= ssif_alert,
1959	.id_table	= ssif_id,
1960	.detect		= ssif_detect
1961};
1962
1963static int init_ipmi_ssif(void)
1964{
1965	int i;
1966	int rv;
1967
1968	if (initialized)
1969		return 0;
1970
1971	pr_info("IPMI SSIF Interface driver\n");
1972
1973	/* build list for i2c from addr list */
1974	for (i = 0; i < num_addrs; i++) {
1975		rv = new_ssif_client(addr[i], adapter_name[i],
1976				     dbg[i], slave_addrs[i],
1977				     SI_HARDCODED);
1978		if (rv)
1979			pr_err(PFX
1980			       "Couldn't add hardcoded device at addr 0x%x\n",
1981			       addr[i]);
1982	}
1983
1984	if (ssif_tryacpi)
1985		ssif_i2c_driver.driver.acpi_match_table	=
1986			ACPI_PTR(ssif_acpi_match);
1987	if (ssif_trydmi)
1988		dmi_iterator();
1989	if (ssif_tryacpi)
1990		spmi_find_bmc();
1991
1992	ssif_i2c_driver.address_list = ssif_address_list();
1993
1994	rv = i2c_add_driver(&ssif_i2c_driver);
1995	if (!rv)
1996		initialized = true;
1997
1998	return rv;
1999}
2000module_init(init_ipmi_ssif);
2001
2002static void cleanup_ipmi_ssif(void)
2003{
2004	if (!initialized)
2005		return;
2006
2007	initialized = false;
2008
2009	i2c_del_driver(&ssif_i2c_driver);
2010
2011	free_ssif_clients();
2012}
2013module_exit(cleanup_ipmi_ssif);
2014
2015MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2016MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2017MODULE_LICENSE("GPL");
2018