Merge tag 'drm-fixes-2018-09-12' of git://anongit.freedesktop.org/drm/drm
[muen/linux.git] / drivers / char / ipmi / ipmi_ssif.c
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 /*
26  * TODO: Figure out how to use SMB alerts.  This will require a new
27  * interface into the I2C driver, I believe.
28  */
29
30 #if defined(MODVERSIONS)
31 #include <linux/modversions.h>
32 #endif
33
34 #include <linux/module.h>
35 #include <linux/moduleparam.h>
36 #include <linux/sched.h>
37 #include <linux/seq_file.h>
38 #include <linux/timer.h>
39 #include <linux/delay.h>
40 #include <linux/errno.h>
41 #include <linux/spinlock.h>
42 #include <linux/slab.h>
43 #include <linux/list.h>
44 #include <linux/i2c.h>
45 #include <linux/ipmi_smi.h>
46 #include <linux/init.h>
47 #include <linux/dmi.h>
48 #include <linux/kthread.h>
49 #include <linux/acpi.h>
50 #include <linux/ctype.h>
51 #include <linux/time64.h>
52 #include "ipmi_si_sm.h"
53 #include "ipmi_dmi.h"
54
55 #define PFX "ipmi_ssif: "
56 #define DEVICE_NAME "ipmi_ssif"
57
58 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
59
60 #define SSIF_IPMI_REQUEST                       2
61 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
62 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
63 #define SSIF_IPMI_RESPONSE                      3
64 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
65
66 /* ssif_debug is a bit-field
67  *      SSIF_DEBUG_MSG -        commands and their responses
68  *      SSIF_DEBUG_STATES -     message states
69  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
70  */
71 #define SSIF_DEBUG_TIMING       4
72 #define SSIF_DEBUG_STATE        2
73 #define SSIF_DEBUG_MSG          1
74 #define SSIF_NODEBUG            0
75 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
76
77 /*
78  * Timer values
79  */
80 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
81 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
82
83 /* How many times to we retry sending/receiving the message. */
84 #define SSIF_SEND_RETRIES       5
85 #define SSIF_RECV_RETRIES       250
86
87 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
88 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
89 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
90
91 enum ssif_intf_state {
92         SSIF_NORMAL,
93         SSIF_GETTING_FLAGS,
94         SSIF_GETTING_EVENTS,
95         SSIF_CLEARING_FLAGS,
96         SSIF_GETTING_MESSAGES,
97         /* FIXME - add watchdog stuff. */
98 };
99
100 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
101                           && (ssif)->curr_msg == NULL)
102
103 /*
104  * Indexes into stats[] in ssif_info below.
105  */
106 enum ssif_stat_indexes {
107         /* Number of total messages sent. */
108         SSIF_STAT_sent_messages = 0,
109
110         /*
111          * Number of message parts sent.  Messages may be broken into
112          * parts if they are long.
113          */
114         SSIF_STAT_sent_messages_parts,
115
116         /*
117          * Number of time a message was retried.
118          */
119         SSIF_STAT_send_retries,
120
121         /*
122          * Number of times the send of a message failed.
123          */
124         SSIF_STAT_send_errors,
125
126         /*
127          * Number of message responses received.
128          */
129         SSIF_STAT_received_messages,
130
131         /*
132          * Number of message fragments received.
133          */
134         SSIF_STAT_received_message_parts,
135
136         /*
137          * Number of times the receive of a message was retried.
138          */
139         SSIF_STAT_receive_retries,
140
141         /*
142          * Number of errors receiving messages.
143          */
144         SSIF_STAT_receive_errors,
145
146         /*
147          * Number of times a flag fetch was requested.
148          */
149         SSIF_STAT_flag_fetches,
150
151         /*
152          * Number of times the hardware didn't follow the state machine.
153          */
154         SSIF_STAT_hosed,
155
156         /*
157          * Number of received events.
158          */
159         SSIF_STAT_events,
160
161         /* Number of asyncronous messages received. */
162         SSIF_STAT_incoming_messages,
163
164         /* Number of watchdog pretimeouts. */
165         SSIF_STAT_watchdog_pretimeouts,
166
167         /* Number of alers received. */
168         SSIF_STAT_alerts,
169
170         /* Always add statistics before this value, it must be last. */
171         SSIF_NUM_STATS
172 };
173
174 struct ssif_addr_info {
175         struct i2c_board_info binfo;
176         char *adapter_name;
177         int debug;
178         int slave_addr;
179         enum ipmi_addr_src addr_src;
180         union ipmi_smi_info_union addr_info;
181         struct device *dev;
182         struct i2c_client *client;
183
184         struct mutex clients_mutex;
185         struct list_head clients;
186
187         struct list_head link;
188 };
189
190 struct ssif_info;
191
192 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
193                              unsigned char *data, unsigned int len);
194
195 struct ssif_info {
196         struct ipmi_smi     *intf;
197         spinlock_t          lock;
198         struct ipmi_smi_msg *waiting_msg;
199         struct ipmi_smi_msg *curr_msg;
200         enum ssif_intf_state ssif_state;
201         unsigned long       ssif_debug;
202
203         struct ipmi_smi_handlers handlers;
204
205         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
206         union ipmi_smi_info_union addr_info;
207
208         /*
209          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
210          * is set to hold the flags until we are done handling everything
211          * from the flags.
212          */
213 #define RECEIVE_MSG_AVAIL       0x01
214 #define EVENT_MSG_BUFFER_FULL   0x02
215 #define WDT_PRE_TIMEOUT_INT     0x08
216         unsigned char       msg_flags;
217
218         u8                  global_enables;
219         bool                has_event_buffer;
220         bool                supports_alert;
221
222         /*
223          * Used to tell what we should do with alerts.  If we are
224          * waiting on a response, read the data immediately.
225          */
226         bool                got_alert;
227         bool                waiting_alert;
228
229         /*
230          * If set to true, this will request events the next time the
231          * state machine is idle.
232          */
233         bool                req_events;
234
235         /*
236          * If set to true, this will request flags the next time the
237          * state machine is idle.
238          */
239         bool                req_flags;
240
241         /*
242          * Used to perform timer operations when run-to-completion
243          * mode is on.  This is a countdown timer.
244          */
245         int                 rtc_us_timer;
246
247         /* Used for sending/receiving data.  +1 for the length. */
248         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
249         unsigned int  data_len;
250
251         /* Temp receive buffer, gets copied into data. */
252         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
253
254         struct i2c_client *client;
255         ssif_i2c_done done_handler;
256
257         /* Thread interface handling */
258         struct task_struct *thread;
259         struct completion wake_thread;
260         bool stopping;
261         int i2c_read_write;
262         int i2c_command;
263         unsigned char *i2c_data;
264         unsigned int i2c_size;
265
266         struct timer_list retry_timer;
267         int retries_left;
268
269         /* Info from SSIF cmd */
270         unsigned char max_xmit_msg_size;
271         unsigned char max_recv_msg_size;
272         unsigned int  multi_support;
273         int           supports_pec;
274
275 #define SSIF_NO_MULTI           0
276 #define SSIF_MULTI_2_PART       1
277 #define SSIF_MULTI_n_PART       2
278         unsigned char *multi_data;
279         unsigned int  multi_len;
280         unsigned int  multi_pos;
281
282         atomic_t stats[SSIF_NUM_STATS];
283 };
284
285 #define ssif_inc_stat(ssif, stat) \
286         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
287 #define ssif_get_stat(ssif, stat) \
288         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
289
290 static bool initialized;
291
292 static void return_hosed_msg(struct ssif_info *ssif_info,
293                              struct ipmi_smi_msg *msg);
294 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
295 static int start_send(struct ssif_info *ssif_info,
296                       unsigned char   *data,
297                       unsigned int    len);
298
299 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
300                                           unsigned long *flags)
301 {
302         spin_lock_irqsave(&ssif_info->lock, *flags);
303         return flags;
304 }
305
306 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
307                                   unsigned long *flags)
308 {
309         spin_unlock_irqrestore(&ssif_info->lock, *flags);
310 }
311
312 static void deliver_recv_msg(struct ssif_info *ssif_info,
313                              struct ipmi_smi_msg *msg)
314 {
315         if (msg->rsp_size < 0) {
316                 return_hosed_msg(ssif_info, msg);
317                 pr_err(PFX
318                        "Malformed message in deliver_recv_msg: rsp_size = %d\n",
319                        msg->rsp_size);
320         } else {
321                 ipmi_smi_msg_received(ssif_info->intf, msg);
322         }
323 }
324
325 static void return_hosed_msg(struct ssif_info *ssif_info,
326                              struct ipmi_smi_msg *msg)
327 {
328         ssif_inc_stat(ssif_info, hosed);
329
330         /* Make it a response */
331         msg->rsp[0] = msg->data[0] | 4;
332         msg->rsp[1] = msg->data[1];
333         msg->rsp[2] = 0xFF; /* Unknown error. */
334         msg->rsp_size = 3;
335
336         deliver_recv_msg(ssif_info, msg);
337 }
338
339 /*
340  * Must be called with the message lock held.  This will release the
341  * message lock.  Note that the caller will check SSIF_IDLE and start a
342  * new operation, so there is no need to check for new messages to
343  * start in here.
344  */
345 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
346 {
347         unsigned char msg[3];
348
349         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
350         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
351         ipmi_ssif_unlock_cond(ssif_info, flags);
352
353         /* Make sure the watchdog pre-timeout flag is not set at startup. */
354         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
355         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
356         msg[2] = WDT_PRE_TIMEOUT_INT;
357
358         if (start_send(ssif_info, msg, 3) != 0) {
359                 /* Error, just go to normal state. */
360                 ssif_info->ssif_state = SSIF_NORMAL;
361         }
362 }
363
364 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
365 {
366         unsigned char mb[2];
367
368         ssif_info->req_flags = false;
369         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
370         ipmi_ssif_unlock_cond(ssif_info, flags);
371
372         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
373         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
374         if (start_send(ssif_info, mb, 2) != 0)
375                 ssif_info->ssif_state = SSIF_NORMAL;
376 }
377
378 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
379                              struct ipmi_smi_msg *msg)
380 {
381         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
382                 unsigned long oflags;
383
384                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
385                 ssif_info->curr_msg = NULL;
386                 ssif_info->ssif_state = SSIF_NORMAL;
387                 ipmi_ssif_unlock_cond(ssif_info, flags);
388                 ipmi_free_smi_msg(msg);
389         }
390 }
391
392 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
393 {
394         struct ipmi_smi_msg *msg;
395
396         ssif_info->req_events = false;
397
398         msg = ipmi_alloc_smi_msg();
399         if (!msg) {
400                 ssif_info->ssif_state = SSIF_NORMAL;
401                 ipmi_ssif_unlock_cond(ssif_info, flags);
402                 return;
403         }
404
405         ssif_info->curr_msg = msg;
406         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
407         ipmi_ssif_unlock_cond(ssif_info, flags);
408
409         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
410         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
411         msg->data_size = 2;
412
413         check_start_send(ssif_info, flags, msg);
414 }
415
416 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
417                                  unsigned long *flags)
418 {
419         struct ipmi_smi_msg *msg;
420
421         msg = ipmi_alloc_smi_msg();
422         if (!msg) {
423                 ssif_info->ssif_state = SSIF_NORMAL;
424                 ipmi_ssif_unlock_cond(ssif_info, flags);
425                 return;
426         }
427
428         ssif_info->curr_msg = msg;
429         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
430         ipmi_ssif_unlock_cond(ssif_info, flags);
431
432         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
433         msg->data[1] = IPMI_GET_MSG_CMD;
434         msg->data_size = 2;
435
436         check_start_send(ssif_info, flags, msg);
437 }
438
439 /*
440  * Must be called with the message lock held.  This will release the
441  * message lock.  Note that the caller will check SSIF_IDLE and start a
442  * new operation, so there is no need to check for new messages to
443  * start in here.
444  */
445 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
446 {
447         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
448                 /* Watchdog pre-timeout */
449                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
450                 start_clear_flags(ssif_info, flags);
451                 ipmi_smi_watchdog_pretimeout(ssif_info->intf);
452         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
453                 /* Messages available. */
454                 start_recv_msg_fetch(ssif_info, flags);
455         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
456                 /* Events available. */
457                 start_event_fetch(ssif_info, flags);
458         else {
459                 ssif_info->ssif_state = SSIF_NORMAL;
460                 ipmi_ssif_unlock_cond(ssif_info, flags);
461         }
462 }
463
464 static int ipmi_ssif_thread(void *data)
465 {
466         struct ssif_info *ssif_info = data;
467
468         while (!kthread_should_stop()) {
469                 int result;
470
471                 /* Wait for something to do */
472                 result = wait_for_completion_interruptible(
473                                                 &ssif_info->wake_thread);
474                 if (ssif_info->stopping)
475                         break;
476                 if (result == -ERESTARTSYS)
477                         continue;
478                 init_completion(&ssif_info->wake_thread);
479
480                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
481                         result = i2c_smbus_write_block_data(
482                                 ssif_info->client, ssif_info->i2c_command,
483                                 ssif_info->i2c_data[0],
484                                 ssif_info->i2c_data + 1);
485                         ssif_info->done_handler(ssif_info, result, NULL, 0);
486                 } else {
487                         result = i2c_smbus_read_block_data(
488                                 ssif_info->client, ssif_info->i2c_command,
489                                 ssif_info->i2c_data);
490                         if (result < 0)
491                                 ssif_info->done_handler(ssif_info, result,
492                                                         NULL, 0);
493                         else
494                                 ssif_info->done_handler(ssif_info, 0,
495                                                         ssif_info->i2c_data,
496                                                         result);
497                 }
498         }
499
500         return 0;
501 }
502
503 static int ssif_i2c_send(struct ssif_info *ssif_info,
504                         ssif_i2c_done handler,
505                         int read_write, int command,
506                         unsigned char *data, unsigned int size)
507 {
508         ssif_info->done_handler = handler;
509
510         ssif_info->i2c_read_write = read_write;
511         ssif_info->i2c_command = command;
512         ssif_info->i2c_data = data;
513         ssif_info->i2c_size = size;
514         complete(&ssif_info->wake_thread);
515         return 0;
516 }
517
518
519 static void msg_done_handler(struct ssif_info *ssif_info, int result,
520                              unsigned char *data, unsigned int len);
521
522 static void start_get(struct ssif_info *ssif_info)
523 {
524         int rv;
525
526         ssif_info->rtc_us_timer = 0;
527         ssif_info->multi_pos = 0;
528
529         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
530                           SSIF_IPMI_RESPONSE,
531                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
532         if (rv < 0) {
533                 /* request failed, just return the error. */
534                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
535                         pr_info("Error from i2c_non_blocking_op(5)\n");
536
537                 msg_done_handler(ssif_info, -EIO, NULL, 0);
538         }
539 }
540
541 static void retry_timeout(struct timer_list *t)
542 {
543         struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
544         unsigned long oflags, *flags;
545         bool waiting;
546
547         if (ssif_info->stopping)
548                 return;
549
550         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
551         waiting = ssif_info->waiting_alert;
552         ssif_info->waiting_alert = false;
553         ipmi_ssif_unlock_cond(ssif_info, flags);
554
555         if (waiting)
556                 start_get(ssif_info);
557 }
558
559
560 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
561                        unsigned int data)
562 {
563         struct ssif_info *ssif_info = i2c_get_clientdata(client);
564         unsigned long oflags, *flags;
565         bool do_get = false;
566
567         if (type != I2C_PROTOCOL_SMBUS_ALERT)
568                 return;
569
570         ssif_inc_stat(ssif_info, alerts);
571
572         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
573         if (ssif_info->waiting_alert) {
574                 ssif_info->waiting_alert = false;
575                 del_timer(&ssif_info->retry_timer);
576                 do_get = true;
577         } else if (ssif_info->curr_msg) {
578                 ssif_info->got_alert = true;
579         }
580         ipmi_ssif_unlock_cond(ssif_info, flags);
581         if (do_get)
582                 start_get(ssif_info);
583 }
584
585 static int start_resend(struct ssif_info *ssif_info);
586
587 static void msg_done_handler(struct ssif_info *ssif_info, int result,
588                              unsigned char *data, unsigned int len)
589 {
590         struct ipmi_smi_msg *msg;
591         unsigned long oflags, *flags;
592         int rv;
593
594         /*
595          * We are single-threaded here, so no need for a lock until we
596          * start messing with driver states or the queues.
597          */
598
599         if (result < 0) {
600                 ssif_info->retries_left--;
601                 if (ssif_info->retries_left > 0) {
602                         ssif_inc_stat(ssif_info, receive_retries);
603
604                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
605                         ssif_info->waiting_alert = true;
606                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
607                         mod_timer(&ssif_info->retry_timer,
608                                   jiffies + SSIF_MSG_JIFFIES);
609                         ipmi_ssif_unlock_cond(ssif_info, flags);
610                         return;
611                 }
612
613                 ssif_inc_stat(ssif_info, receive_errors);
614
615                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
616                         pr_info("Error in msg_done_handler: %d\n", result);
617                 len = 0;
618                 goto continue_op;
619         }
620
621         if ((len > 1) && (ssif_info->multi_pos == 0)
622                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
623                 /* Start of multi-part read.  Start the next transaction. */
624                 int i;
625
626                 ssif_inc_stat(ssif_info, received_message_parts);
627
628                 /* Remove the multi-part read marker. */
629                 len -= 2;
630                 for (i = 0; i < len; i++)
631                         ssif_info->data[i] = data[i+2];
632                 ssif_info->multi_len = len;
633                 ssif_info->multi_pos = 1;
634
635                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
636                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
637                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
638                 if (rv < 0) {
639                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
640                                 pr_info("Error from i2c_non_blocking_op(1)\n");
641
642                         result = -EIO;
643                 } else
644                         return;
645         } else if (ssif_info->multi_pos) {
646                 /* Middle of multi-part read.  Start the next transaction. */
647                 int i;
648                 unsigned char blocknum;
649
650                 if (len == 0) {
651                         result = -EIO;
652                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
653                                 pr_info(PFX "Middle message with no data\n");
654
655                         goto continue_op;
656                 }
657
658                 blocknum = data[0];
659
660                 if (ssif_info->multi_len + len - 1 > IPMI_MAX_MSG_LENGTH) {
661                         /* Received message too big, abort the operation. */
662                         result = -E2BIG;
663                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
664                                 pr_info("Received message too big\n");
665
666                         goto continue_op;
667                 }
668
669                 /* Remove the blocknum from the data. */
670                 len--;
671                 for (i = 0; i < len; i++)
672                         ssif_info->data[i + ssif_info->multi_len] = data[i + 1];
673                 ssif_info->multi_len += len;
674                 if (blocknum == 0xff) {
675                         /* End of read */
676                         len = ssif_info->multi_len;
677                         data = ssif_info->data;
678                 } else if (blocknum + 1 != ssif_info->multi_pos) {
679                         /*
680                          * Out of sequence block, just abort.  Block
681                          * numbers start at zero for the second block,
682                          * but multi_pos starts at one, so the +1.
683                          */
684                         result = -EIO;
685                 } else {
686                         ssif_inc_stat(ssif_info, received_message_parts);
687
688                         ssif_info->multi_pos++;
689
690                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
691                                            I2C_SMBUS_READ,
692                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
693                                            ssif_info->recv,
694                                            I2C_SMBUS_BLOCK_DATA);
695                         if (rv < 0) {
696                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
697                                         pr_info(PFX
698                                                 "Error from ssif_i2c_send\n");
699
700                                 result = -EIO;
701                         } else
702                                 return;
703                 }
704         }
705
706         if (result < 0) {
707                 ssif_inc_stat(ssif_info, receive_errors);
708         } else {
709                 ssif_inc_stat(ssif_info, received_messages);
710                 ssif_inc_stat(ssif_info, received_message_parts);
711         }
712
713
714  continue_op:
715         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
716                 pr_info(PFX "DONE 1: state = %d, result=%d.\n",
717                         ssif_info->ssif_state, result);
718
719         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
720         msg = ssif_info->curr_msg;
721         if (msg) {
722                 msg->rsp_size = len;
723                 if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
724                         msg->rsp_size = IPMI_MAX_MSG_LENGTH;
725                 memcpy(msg->rsp, data, msg->rsp_size);
726                 ssif_info->curr_msg = NULL;
727         }
728
729         switch (ssif_info->ssif_state) {
730         case SSIF_NORMAL:
731                 ipmi_ssif_unlock_cond(ssif_info, flags);
732                 if (!msg)
733                         break;
734
735                 if (result < 0)
736                         return_hosed_msg(ssif_info, msg);
737                 else
738                         deliver_recv_msg(ssif_info, msg);
739                 break;
740
741         case SSIF_GETTING_FLAGS:
742                 /* We got the flags from the SSIF, now handle them. */
743                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
744                         /*
745                          * Error fetching flags, or invalid length,
746                          * just give up for now.
747                          */
748                         ssif_info->ssif_state = SSIF_NORMAL;
749                         ipmi_ssif_unlock_cond(ssif_info, flags);
750                         pr_warn(PFX "Error getting flags: %d %d, %x\n",
751                                result, len, (len >= 3) ? data[2] : 0);
752                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
753                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
754                         /*
755                          * Don't abort here, maybe it was a queued
756                          * response to a previous command.
757                          */
758                         ipmi_ssif_unlock_cond(ssif_info, flags);
759                         pr_warn(PFX "Invalid response getting flags: %x %x\n",
760                                 data[0], data[1]);
761                 } else {
762                         ssif_inc_stat(ssif_info, flag_fetches);
763                         ssif_info->msg_flags = data[3];
764                         handle_flags(ssif_info, flags);
765                 }
766                 break;
767
768         case SSIF_CLEARING_FLAGS:
769                 /* We cleared the flags. */
770                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
771                         /* Error clearing flags */
772                         pr_warn(PFX "Error clearing flags: %d %d, %x\n",
773                                result, len, (len >= 3) ? data[2] : 0);
774                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
775                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
776                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
777                                 data[0], data[1]);
778                 }
779                 ssif_info->ssif_state = SSIF_NORMAL;
780                 ipmi_ssif_unlock_cond(ssif_info, flags);
781                 break;
782
783         case SSIF_GETTING_EVENTS:
784                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
785                         /* Error getting event, probably done. */
786                         msg->done(msg);
787
788                         /* Take off the event flag. */
789                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
790                         handle_flags(ssif_info, flags);
791                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
792                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
793                         pr_warn(PFX "Invalid response getting events: %x %x\n",
794                                 msg->rsp[0], msg->rsp[1]);
795                         msg->done(msg);
796                         /* Take off the event flag. */
797                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
798                         handle_flags(ssif_info, flags);
799                 } else {
800                         handle_flags(ssif_info, flags);
801                         ssif_inc_stat(ssif_info, events);
802                         deliver_recv_msg(ssif_info, msg);
803                 }
804                 break;
805
806         case SSIF_GETTING_MESSAGES:
807                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
808                         /* Error getting event, probably done. */
809                         msg->done(msg);
810
811                         /* Take off the msg flag. */
812                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
813                         handle_flags(ssif_info, flags);
814                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
815                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
816                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
817                                 msg->rsp[0], msg->rsp[1]);
818                         msg->done(msg);
819
820                         /* Take off the msg flag. */
821                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
822                         handle_flags(ssif_info, flags);
823                 } else {
824                         ssif_inc_stat(ssif_info, incoming_messages);
825                         handle_flags(ssif_info, flags);
826                         deliver_recv_msg(ssif_info, msg);
827                 }
828                 break;
829         }
830
831         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
832         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
833                 if (ssif_info->req_events)
834                         start_event_fetch(ssif_info, flags);
835                 else if (ssif_info->req_flags)
836                         start_flag_fetch(ssif_info, flags);
837                 else
838                         start_next_msg(ssif_info, flags);
839         } else
840                 ipmi_ssif_unlock_cond(ssif_info, flags);
841
842         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
843                 pr_info(PFX "DONE 2: state = %d.\n", ssif_info->ssif_state);
844 }
845
846 static void msg_written_handler(struct ssif_info *ssif_info, int result,
847                                 unsigned char *data, unsigned int len)
848 {
849         int rv;
850
851         /* We are single-threaded here, so no need for a lock. */
852         if (result < 0) {
853                 ssif_info->retries_left--;
854                 if (ssif_info->retries_left > 0) {
855                         if (!start_resend(ssif_info)) {
856                                 ssif_inc_stat(ssif_info, send_retries);
857                                 return;
858                         }
859                         /* request failed, just return the error. */
860                         ssif_inc_stat(ssif_info, send_errors);
861
862                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
863                                 pr_info(PFX
864                                         "Out of retries in msg_written_handler\n");
865                         msg_done_handler(ssif_info, -EIO, NULL, 0);
866                         return;
867                 }
868
869                 ssif_inc_stat(ssif_info, send_errors);
870
871                 /*
872                  * Got an error on transmit, let the done routine
873                  * handle it.
874                  */
875                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
876                         pr_info("Error in msg_written_handler: %d\n", result);
877
878                 msg_done_handler(ssif_info, result, NULL, 0);
879                 return;
880         }
881
882         if (ssif_info->multi_data) {
883                 /*
884                  * In the middle of a multi-data write.  See the comment
885                  * in the SSIF_MULTI_n_PART case in the probe function
886                  * for details on the intricacies of this.
887                  */
888                 int left;
889                 unsigned char *data_to_send;
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                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
899                 ssif_info->multi_pos += left;
900                 if (left < 32)
901                         /*
902                          * Write is finished.  Note that we must end
903                          * with a write of less than 32 bytes to
904                          * complete the transaction, even if it is
905                          * zero bytes.
906                          */
907                         ssif_info->multi_data = NULL;
908
909                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
910                                   I2C_SMBUS_WRITE,
911                                   SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
912                                   data_to_send,
913                                   I2C_SMBUS_BLOCK_DATA);
914                 if (rv < 0) {
915                         /* request failed, just return the error. */
916                         ssif_inc_stat(ssif_info, send_errors);
917
918                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
919                                 pr_info("Error from i2c_non_blocking_op(3)\n");
920                         msg_done_handler(ssif_info, -EIO, NULL, 0);
921                 }
922         } else {
923                 /* Ready to request the result. */
924                 unsigned long oflags, *flags;
925
926                 ssif_inc_stat(ssif_info, sent_messages);
927                 ssif_inc_stat(ssif_info, sent_messages_parts);
928
929                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
930                 if (ssif_info->got_alert) {
931                         /* The result is already ready, just start it. */
932                         ssif_info->got_alert = false;
933                         ipmi_ssif_unlock_cond(ssif_info, flags);
934                         start_get(ssif_info);
935                 } else {
936                         /* Wait a jiffie then request the next message */
937                         ssif_info->waiting_alert = true;
938                         ssif_info->retries_left = SSIF_RECV_RETRIES;
939                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
940                         mod_timer(&ssif_info->retry_timer,
941                                   jiffies + SSIF_MSG_PART_JIFFIES);
942                         ipmi_ssif_unlock_cond(ssif_info, flags);
943                 }
944         }
945 }
946
947 static int start_resend(struct ssif_info *ssif_info)
948 {
949         int rv;
950         int command;
951
952         ssif_info->got_alert = false;
953
954         if (ssif_info->data_len > 32) {
955                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
956                 ssif_info->multi_data = ssif_info->data;
957                 ssif_info->multi_len = ssif_info->data_len;
958                 /*
959                  * Subtle thing, this is 32, not 33, because we will
960                  * overwrite the thing at position 32 (which was just
961                  * transmitted) with the new length.
962                  */
963                 ssif_info->multi_pos = 32;
964                 ssif_info->data[0] = 32;
965         } else {
966                 ssif_info->multi_data = NULL;
967                 command = SSIF_IPMI_REQUEST;
968                 ssif_info->data[0] = ssif_info->data_len;
969         }
970
971         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
972                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
973         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
974                 pr_info("Error from i2c_non_blocking_op(4)\n");
975         return rv;
976 }
977
978 static int start_send(struct ssif_info *ssif_info,
979                       unsigned char   *data,
980                       unsigned int    len)
981 {
982         if (len > IPMI_MAX_MSG_LENGTH)
983                 return -E2BIG;
984         if (len > ssif_info->max_xmit_msg_size)
985                 return -E2BIG;
986
987         ssif_info->retries_left = SSIF_SEND_RETRIES;
988         memcpy(ssif_info->data + 1, data, len);
989         ssif_info->data_len = len;
990         return start_resend(ssif_info);
991 }
992
993 /* Must be called with the message lock held. */
994 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
995 {
996         struct ipmi_smi_msg *msg;
997         unsigned long oflags;
998
999  restart:
1000         if (!SSIF_IDLE(ssif_info)) {
1001                 ipmi_ssif_unlock_cond(ssif_info, flags);
1002                 return;
1003         }
1004
1005         if (!ssif_info->waiting_msg) {
1006                 ssif_info->curr_msg = NULL;
1007                 ipmi_ssif_unlock_cond(ssif_info, flags);
1008         } else {
1009                 int rv;
1010
1011                 ssif_info->curr_msg = ssif_info->waiting_msg;
1012                 ssif_info->waiting_msg = NULL;
1013                 ipmi_ssif_unlock_cond(ssif_info, flags);
1014                 rv = start_send(ssif_info,
1015                                 ssif_info->curr_msg->data,
1016                                 ssif_info->curr_msg->data_size);
1017                 if (rv) {
1018                         msg = ssif_info->curr_msg;
1019                         ssif_info->curr_msg = NULL;
1020                         return_hosed_msg(ssif_info, msg);
1021                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1022                         goto restart;
1023                 }
1024         }
1025 }
1026
1027 static void sender(void                *send_info,
1028                    struct ipmi_smi_msg *msg)
1029 {
1030         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1031         unsigned long oflags, *flags;
1032
1033         BUG_ON(ssif_info->waiting_msg);
1034         ssif_info->waiting_msg = msg;
1035
1036         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1037         start_next_msg(ssif_info, flags);
1038
1039         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1040                 struct timespec64 t;
1041
1042                 ktime_get_real_ts64(&t);
1043                 pr_info("**Enqueue %02x %02x: %lld.%6.6ld\n",
1044                        msg->data[0], msg->data[1],
1045                        (long long) t.tv_sec, (long) t.tv_nsec / NSEC_PER_USEC);
1046         }
1047 }
1048
1049 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1050 {
1051         struct ssif_info *ssif_info = send_info;
1052
1053         data->addr_src = ssif_info->addr_source;
1054         data->dev = &ssif_info->client->dev;
1055         data->addr_info = ssif_info->addr_info;
1056         get_device(data->dev);
1057
1058         return 0;
1059 }
1060
1061 /*
1062  * Instead of having our own timer to periodically check the message
1063  * flags, we let the message handler drive us.
1064  */
1065 static void request_events(void *send_info)
1066 {
1067         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1068         unsigned long oflags, *flags;
1069
1070         if (!ssif_info->has_event_buffer)
1071                 return;
1072
1073         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1074         /*
1075          * Request flags first, not events, because the lower layer
1076          * doesn't have a way to send an attention.  But make sure
1077          * event checking still happens.
1078          */
1079         ssif_info->req_events = true;
1080         if (SSIF_IDLE(ssif_info))
1081                 start_flag_fetch(ssif_info, flags);
1082         else {
1083                 ssif_info->req_flags = true;
1084                 ipmi_ssif_unlock_cond(ssif_info, flags);
1085         }
1086 }
1087
1088 static int ssif_start_processing(void            *send_info,
1089                                  struct ipmi_smi *intf)
1090 {
1091         struct ssif_info *ssif_info = send_info;
1092
1093         ssif_info->intf = intf;
1094
1095         return 0;
1096 }
1097
1098 #define MAX_SSIF_BMCS 4
1099
1100 static unsigned short addr[MAX_SSIF_BMCS];
1101 static int num_addrs;
1102 module_param_array(addr, ushort, &num_addrs, 0);
1103 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1104
1105 static char *adapter_name[MAX_SSIF_BMCS];
1106 static int num_adapter_names;
1107 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1108 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1109
1110 static int slave_addrs[MAX_SSIF_BMCS];
1111 static int num_slave_addrs;
1112 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1113 MODULE_PARM_DESC(slave_addrs,
1114                  "The default IPMB slave address for the controller.");
1115
1116 static bool alerts_broken;
1117 module_param(alerts_broken, bool, 0);
1118 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1119
1120 /*
1121  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1122  * bit 2 enables timing debugging.  This is an array indexed by
1123  * interface number"
1124  */
1125 static int dbg[MAX_SSIF_BMCS];
1126 static int num_dbg;
1127 module_param_array(dbg, int, &num_dbg, 0);
1128 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1129
1130 static bool ssif_dbg_probe;
1131 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1132 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1133
1134 static bool ssif_tryacpi = true;
1135 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1136 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1137
1138 static bool ssif_trydmi = true;
1139 module_param_named(trydmi, ssif_trydmi, bool, 0);
1140 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1141
1142 static DEFINE_MUTEX(ssif_infos_mutex);
1143 static LIST_HEAD(ssif_infos);
1144
1145 #define IPMI_SSIF_ATTR(name) \
1146 static ssize_t ipmi_##name##_show(struct device *dev,                   \
1147                                   struct device_attribute *attr,        \
1148                                   char *buf)                            \
1149 {                                                                       \
1150         struct ssif_info *ssif_info = dev_get_drvdata(dev);             \
1151                                                                         \
1152         return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1153 }                                                                       \
1154 static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1155
1156 static ssize_t ipmi_type_show(struct device *dev,
1157                               struct device_attribute *attr,
1158                               char *buf)
1159 {
1160         return snprintf(buf, 10, "ssif\n");
1161 }
1162 static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1163
1164 IPMI_SSIF_ATTR(sent_messages);
1165 IPMI_SSIF_ATTR(sent_messages_parts);
1166 IPMI_SSIF_ATTR(send_retries);
1167 IPMI_SSIF_ATTR(send_errors);
1168 IPMI_SSIF_ATTR(received_messages);
1169 IPMI_SSIF_ATTR(received_message_parts);
1170 IPMI_SSIF_ATTR(receive_retries);
1171 IPMI_SSIF_ATTR(receive_errors);
1172 IPMI_SSIF_ATTR(flag_fetches);
1173 IPMI_SSIF_ATTR(hosed);
1174 IPMI_SSIF_ATTR(events);
1175 IPMI_SSIF_ATTR(watchdog_pretimeouts);
1176 IPMI_SSIF_ATTR(alerts);
1177
1178 static struct attribute *ipmi_ssif_dev_attrs[] = {
1179         &dev_attr_type.attr,
1180         &dev_attr_sent_messages.attr,
1181         &dev_attr_sent_messages_parts.attr,
1182         &dev_attr_send_retries.attr,
1183         &dev_attr_send_errors.attr,
1184         &dev_attr_received_messages.attr,
1185         &dev_attr_received_message_parts.attr,
1186         &dev_attr_receive_retries.attr,
1187         &dev_attr_receive_errors.attr,
1188         &dev_attr_flag_fetches.attr,
1189         &dev_attr_hosed.attr,
1190         &dev_attr_events.attr,
1191         &dev_attr_watchdog_pretimeouts.attr,
1192         &dev_attr_alerts.attr,
1193         NULL
1194 };
1195
1196 static const struct attribute_group ipmi_ssif_dev_attr_group = {
1197         .attrs          = ipmi_ssif_dev_attrs,
1198 };
1199
1200 static void shutdown_ssif(void *send_info)
1201 {
1202         struct ssif_info *ssif_info = send_info;
1203
1204         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1205         dev_set_drvdata(&ssif_info->client->dev, NULL);
1206
1207         /* make sure the driver is not looking for flags any more. */
1208         while (ssif_info->ssif_state != SSIF_NORMAL)
1209                 schedule_timeout(1);
1210
1211         ssif_info->stopping = true;
1212         del_timer_sync(&ssif_info->retry_timer);
1213         if (ssif_info->thread) {
1214                 complete(&ssif_info->wake_thread);
1215                 kthread_stop(ssif_info->thread);
1216         }
1217
1218         /*
1219          * No message can be outstanding now, we have removed the
1220          * upper layer and it permitted us to do so.
1221          */
1222         kfree(ssif_info);
1223 }
1224
1225 static int ssif_remove(struct i2c_client *client)
1226 {
1227         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1228         struct ipmi_smi *intf;
1229         struct ssif_addr_info *addr_info;
1230
1231         if (!ssif_info)
1232                 return 0;
1233
1234         /*
1235          * After this point, we won't deliver anything asychronously
1236          * to the message handler.  We can unregister ourself.
1237          */
1238         intf = ssif_info->intf;
1239         ssif_info->intf = NULL;
1240         ipmi_unregister_smi(intf);
1241
1242         list_for_each_entry(addr_info, &ssif_infos, link) {
1243                 if (addr_info->client == client) {
1244                         addr_info->client = NULL;
1245                         break;
1246                 }
1247         }
1248
1249         return 0;
1250 }
1251
1252 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1253                   int *resp_len, unsigned char *resp)
1254 {
1255         int retry_cnt;
1256         int ret;
1257
1258         retry_cnt = SSIF_SEND_RETRIES;
1259  retry1:
1260         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1261         if (ret) {
1262                 retry_cnt--;
1263                 if (retry_cnt > 0)
1264                         goto retry1;
1265                 return -ENODEV;
1266         }
1267
1268         ret = -ENODEV;
1269         retry_cnt = SSIF_RECV_RETRIES;
1270         while (retry_cnt > 0) {
1271                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1272                                                 resp);
1273                 if (ret > 0)
1274                         break;
1275                 msleep(SSIF_MSG_MSEC);
1276                 retry_cnt--;
1277                 if (retry_cnt <= 0)
1278                         break;
1279         }
1280
1281         if (ret > 0) {
1282                 /* Validate that the response is correct. */
1283                 if (ret < 3 ||
1284                     (resp[0] != (msg[0] | (1 << 2))) ||
1285                     (resp[1] != msg[1]))
1286                         ret = -EINVAL;
1287                 else {
1288                         *resp_len = ret;
1289                         ret = 0;
1290                 }
1291         }
1292
1293         return ret;
1294 }
1295
1296 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1297 {
1298         unsigned char *resp;
1299         unsigned char msg[3];
1300         int           rv;
1301         int           len;
1302
1303         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1304         if (!resp)
1305                 return -ENOMEM;
1306
1307         /* Do a Get Device ID command, since it is required. */
1308         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1309         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1310         rv = do_cmd(client, 2, msg, &len, resp);
1311         if (rv)
1312                 rv = -ENODEV;
1313         else
1314                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1315         kfree(resp);
1316         return rv;
1317 }
1318
1319 static int strcmp_nospace(char *s1, char *s2)
1320 {
1321         while (*s1 && *s2) {
1322                 while (isspace(*s1))
1323                         s1++;
1324                 while (isspace(*s2))
1325                         s2++;
1326                 if (*s1 > *s2)
1327                         return 1;
1328                 if (*s1 < *s2)
1329                         return -1;
1330                 s1++;
1331                 s2++;
1332         }
1333         return 0;
1334 }
1335
1336 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1337                                              char *adapter_name,
1338                                              bool match_null_name)
1339 {
1340         struct ssif_addr_info *info, *found = NULL;
1341
1342 restart:
1343         list_for_each_entry(info, &ssif_infos, link) {
1344                 if (info->binfo.addr == addr) {
1345                         if (info->adapter_name || adapter_name) {
1346                                 if (!info->adapter_name != !adapter_name) {
1347                                         /* One is NULL and one is not */
1348                                         continue;
1349                                 }
1350                                 if (adapter_name &&
1351                                     strcmp_nospace(info->adapter_name,
1352                                                    adapter_name))
1353                                         /* Names do not match */
1354                                         continue;
1355                         }
1356                         found = info;
1357                         break;
1358                 }
1359         }
1360
1361         if (!found && match_null_name) {
1362                 /* Try to get an exact match first, then try with a NULL name */
1363                 adapter_name = NULL;
1364                 match_null_name = false;
1365                 goto restart;
1366         }
1367
1368         return found;
1369 }
1370
1371 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1372 {
1373 #ifdef CONFIG_ACPI
1374         acpi_handle acpi_handle;
1375
1376         acpi_handle = ACPI_HANDLE(dev);
1377         if (acpi_handle) {
1378                 ssif_info->addr_source = SI_ACPI;
1379                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1380                 return true;
1381         }
1382 #endif
1383         return false;
1384 }
1385
1386 static int find_slave_address(struct i2c_client *client, int slave_addr)
1387 {
1388 #ifdef CONFIG_IPMI_DMI_DECODE
1389         if (!slave_addr)
1390                 slave_addr = ipmi_dmi_get_slave_addr(
1391                         SI_TYPE_INVALID,
1392                         i2c_adapter_id(client->adapter),
1393                         client->addr);
1394 #endif
1395
1396         return slave_addr;
1397 }
1398
1399 /*
1400  * Global enables we care about.
1401  */
1402 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1403                              IPMI_BMC_EVT_MSG_INTR)
1404
1405 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1406 {
1407         unsigned char     msg[3];
1408         unsigned char     *resp;
1409         struct ssif_info   *ssif_info;
1410         int               rv = 0;
1411         int               len;
1412         int               i;
1413         u8                slave_addr = 0;
1414         struct ssif_addr_info *addr_info = NULL;
1415
1416         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1417         if (!resp)
1418                 return -ENOMEM;
1419
1420         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1421         if (!ssif_info) {
1422                 kfree(resp);
1423                 return -ENOMEM;
1424         }
1425
1426         if (!check_acpi(ssif_info, &client->dev)) {
1427                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1428                                            true);
1429                 if (!addr_info) {
1430                         /* Must have come in through sysfs. */
1431                         ssif_info->addr_source = SI_HOTMOD;
1432                 } else {
1433                         ssif_info->addr_source = addr_info->addr_src;
1434                         ssif_info->ssif_debug = addr_info->debug;
1435                         ssif_info->addr_info = addr_info->addr_info;
1436                         addr_info->client = client;
1437                         slave_addr = addr_info->slave_addr;
1438                 }
1439         }
1440
1441         slave_addr = find_slave_address(client, slave_addr);
1442
1443         pr_info(PFX "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1444                ipmi_addr_src_to_str(ssif_info->addr_source),
1445                client->addr, client->adapter->name, slave_addr);
1446
1447         ssif_info->client = client;
1448         i2c_set_clientdata(client, ssif_info);
1449
1450         /* Now check for system interface capabilities */
1451         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1452         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1453         msg[2] = 0; /* SSIF */
1454         rv = do_cmd(client, 3, msg, &len, resp);
1455         if (!rv && (len >= 3) && (resp[2] == 0)) {
1456                 if (len < 7) {
1457                         if (ssif_dbg_probe)
1458                                 pr_info(PFX "SSIF info too short: %d\n", len);
1459                         goto no_support;
1460                 }
1461
1462                 /* Got a good SSIF response, handle it. */
1463                 ssif_info->max_xmit_msg_size = resp[5];
1464                 ssif_info->max_recv_msg_size = resp[6];
1465                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1466                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1467
1468                 /* Sanitize the data */
1469                 switch (ssif_info->multi_support) {
1470                 case SSIF_NO_MULTI:
1471                         if (ssif_info->max_xmit_msg_size > 32)
1472                                 ssif_info->max_xmit_msg_size = 32;
1473                         if (ssif_info->max_recv_msg_size > 32)
1474                                 ssif_info->max_recv_msg_size = 32;
1475                         break;
1476
1477                 case SSIF_MULTI_2_PART:
1478                         if (ssif_info->max_xmit_msg_size > 63)
1479                                 ssif_info->max_xmit_msg_size = 63;
1480                         if (ssif_info->max_recv_msg_size > 62)
1481                                 ssif_info->max_recv_msg_size = 62;
1482                         break;
1483
1484                 case SSIF_MULTI_n_PART:
1485                         /*
1486                          * The specification is rather confusing at
1487                          * this point, but I think I understand what
1488                          * is meant.  At least I have a workable
1489                          * solution.  With multi-part messages, you
1490                          * cannot send a message that is a multiple of
1491                          * 32-bytes in length, because the start and
1492                          * middle messages are 32-bytes and the end
1493                          * message must be at least one byte.  You
1494                          * can't fudge on an extra byte, that would
1495                          * screw up things like fru data writes.  So
1496                          * we limit the length to 63 bytes.  That way
1497                          * a 32-byte message gets sent as a single
1498                          * part.  A larger message will be a 32-byte
1499                          * start and the next message is always going
1500                          * to be 1-31 bytes in length.  Not ideal, but
1501                          * it should work.
1502                          */
1503                         if (ssif_info->max_xmit_msg_size > 63)
1504                                 ssif_info->max_xmit_msg_size = 63;
1505                         break;
1506
1507                 default:
1508                         /* Data is not sane, just give up. */
1509                         goto no_support;
1510                 }
1511         } else {
1512  no_support:
1513                 /* Assume no multi-part or PEC support */
1514                 pr_info(PFX "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1515                        rv, len, resp[2]);
1516
1517                 ssif_info->max_xmit_msg_size = 32;
1518                 ssif_info->max_recv_msg_size = 32;
1519                 ssif_info->multi_support = SSIF_NO_MULTI;
1520                 ssif_info->supports_pec = 0;
1521         }
1522
1523         /* Make sure the NMI timeout is cleared. */
1524         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1525         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1526         msg[2] = WDT_PRE_TIMEOUT_INT;
1527         rv = do_cmd(client, 3, msg, &len, resp);
1528         if (rv || (len < 3) || (resp[2] != 0))
1529                 pr_warn(PFX "Unable to clear message flags: %d %d %2.2x\n",
1530                         rv, len, resp[2]);
1531
1532         /* Attempt to enable the event buffer. */
1533         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1534         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1535         rv = do_cmd(client, 2, msg, &len, resp);
1536         if (rv || (len < 4) || (resp[2] != 0)) {
1537                 pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
1538                         rv, len, resp[2]);
1539                 rv = 0; /* Not fatal */
1540                 goto found;
1541         }
1542
1543         ssif_info->global_enables = resp[3];
1544
1545         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1546                 ssif_info->has_event_buffer = true;
1547                 /* buffer is already enabled, nothing to do. */
1548                 goto found;
1549         }
1550
1551         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1552         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1553         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1554         rv = do_cmd(client, 3, msg, &len, resp);
1555         if (rv || (len < 2)) {
1556                 pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1557                         rv, len, resp[2]);
1558                 rv = 0; /* Not fatal */
1559                 goto found;
1560         }
1561
1562         if (resp[2] == 0) {
1563                 /* A successful return means the event buffer is supported. */
1564                 ssif_info->has_event_buffer = true;
1565                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1566         }
1567
1568         /* Some systems don't behave well if you enable alerts. */
1569         if (alerts_broken)
1570                 goto found;
1571
1572         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1573         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1574         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1575         rv = do_cmd(client, 3, msg, &len, resp);
1576         if (rv || (len < 2)) {
1577                 pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1578                         rv, len, resp[2]);
1579                 rv = 0; /* Not fatal */
1580                 goto found;
1581         }
1582
1583         if (resp[2] == 0) {
1584                 /* A successful return means the alert is supported. */
1585                 ssif_info->supports_alert = true;
1586                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1587         }
1588
1589  found:
1590         if (ssif_dbg_probe) {
1591                 pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
1592                         client->addr);
1593         }
1594
1595         spin_lock_init(&ssif_info->lock);
1596         ssif_info->ssif_state = SSIF_NORMAL;
1597         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1598
1599         for (i = 0; i < SSIF_NUM_STATS; i++)
1600                 atomic_set(&ssif_info->stats[i], 0);
1601
1602         if (ssif_info->supports_pec)
1603                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1604
1605         ssif_info->handlers.owner = THIS_MODULE;
1606         ssif_info->handlers.start_processing = ssif_start_processing;
1607         ssif_info->handlers.shutdown = shutdown_ssif;
1608         ssif_info->handlers.get_smi_info = get_smi_info;
1609         ssif_info->handlers.sender = sender;
1610         ssif_info->handlers.request_events = request_events;
1611
1612         {
1613                 unsigned int thread_num;
1614
1615                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1616                                << 8) |
1617                               ssif_info->client->addr);
1618                 init_completion(&ssif_info->wake_thread);
1619                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1620                                                "kssif%4.4x", thread_num);
1621                 if (IS_ERR(ssif_info->thread)) {
1622                         rv = PTR_ERR(ssif_info->thread);
1623                         dev_notice(&ssif_info->client->dev,
1624                                    "Could not start kernel thread: error %d\n",
1625                                    rv);
1626                         goto out;
1627                 }
1628         }
1629
1630         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1631         rv = device_add_group(&ssif_info->client->dev,
1632                               &ipmi_ssif_dev_attr_group);
1633         if (rv) {
1634                 dev_err(&ssif_info->client->dev,
1635                         "Unable to add device attributes: error %d\n",
1636                         rv);
1637                 goto out;
1638         }
1639
1640         rv = ipmi_register_smi(&ssif_info->handlers,
1641                                ssif_info,
1642                                &ssif_info->client->dev,
1643                                slave_addr);
1644          if (rv) {
1645                 pr_err(PFX "Unable to register device: error %d\n", rv);
1646                 goto out_remove_attr;
1647         }
1648
1649  out:
1650         if (rv) {
1651                 /*
1652                  * Note that if addr_info->client is assigned, we
1653                  * leave it.  The i2c client hangs around even if we
1654                  * return a failure here, and the failure here is not
1655                  * propagated back to the i2c code.  This seems to be
1656                  * design intent, strange as it may be.  But if we
1657                  * don't leave it, ssif_platform_remove will not remove
1658                  * the client like it should.
1659                  */
1660                 dev_err(&client->dev, "Unable to start IPMI SSIF: %d\n", rv);
1661                 kfree(ssif_info);
1662         }
1663         kfree(resp);
1664         return rv;
1665
1666 out_remove_attr:
1667         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1668         dev_set_drvdata(&ssif_info->client->dev, NULL);
1669         goto out;
1670 }
1671
1672 static int ssif_adapter_handler(struct device *adev, void *opaque)
1673 {
1674         struct ssif_addr_info *addr_info = opaque;
1675
1676         if (adev->type != &i2c_adapter_type)
1677                 return 0;
1678
1679         i2c_new_device(to_i2c_adapter(adev), &addr_info->binfo);
1680
1681         if (!addr_info->adapter_name)
1682                 return 1; /* Only try the first I2C adapter by default. */
1683         return 0;
1684 }
1685
1686 static int new_ssif_client(int addr, char *adapter_name,
1687                            int debug, int slave_addr,
1688                            enum ipmi_addr_src addr_src,
1689                            struct device *dev)
1690 {
1691         struct ssif_addr_info *addr_info;
1692         int rv = 0;
1693
1694         mutex_lock(&ssif_infos_mutex);
1695         if (ssif_info_find(addr, adapter_name, false)) {
1696                 rv = -EEXIST;
1697                 goto out_unlock;
1698         }
1699
1700         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1701         if (!addr_info) {
1702                 rv = -ENOMEM;
1703                 goto out_unlock;
1704         }
1705
1706         if (adapter_name) {
1707                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1708                 if (!addr_info->adapter_name) {
1709                         kfree(addr_info);
1710                         rv = -ENOMEM;
1711                         goto out_unlock;
1712                 }
1713         }
1714
1715         strncpy(addr_info->binfo.type, DEVICE_NAME,
1716                 sizeof(addr_info->binfo.type));
1717         addr_info->binfo.addr = addr;
1718         addr_info->binfo.platform_data = addr_info;
1719         addr_info->debug = debug;
1720         addr_info->slave_addr = slave_addr;
1721         addr_info->addr_src = addr_src;
1722         addr_info->dev = dev;
1723
1724         if (dev)
1725                 dev_set_drvdata(dev, addr_info);
1726
1727         list_add_tail(&addr_info->link, &ssif_infos);
1728
1729         if (initialized)
1730                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1731         /* Otherwise address list will get it */
1732
1733 out_unlock:
1734         mutex_unlock(&ssif_infos_mutex);
1735         return rv;
1736 }
1737
1738 static void free_ssif_clients(void)
1739 {
1740         struct ssif_addr_info *info, *tmp;
1741
1742         mutex_lock(&ssif_infos_mutex);
1743         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1744                 list_del(&info->link);
1745                 kfree(info->adapter_name);
1746                 kfree(info);
1747         }
1748         mutex_unlock(&ssif_infos_mutex);
1749 }
1750
1751 static unsigned short *ssif_address_list(void)
1752 {
1753         struct ssif_addr_info *info;
1754         unsigned int count = 0, i;
1755         unsigned short *address_list;
1756
1757         list_for_each_entry(info, &ssif_infos, link)
1758                 count++;
1759
1760         address_list = kcalloc(count + 1, sizeof(*address_list),
1761                                GFP_KERNEL);
1762         if (!address_list)
1763                 return NULL;
1764
1765         i = 0;
1766         list_for_each_entry(info, &ssif_infos, link) {
1767                 unsigned short addr = info->binfo.addr;
1768                 int j;
1769
1770                 for (j = 0; j < i; j++) {
1771                         if (address_list[j] == addr)
1772                                 goto skip_addr;
1773                 }
1774                 address_list[i] = addr;
1775 skip_addr:
1776                 i++;
1777         }
1778         address_list[i] = I2C_CLIENT_END;
1779
1780         return address_list;
1781 }
1782
1783 #ifdef CONFIG_ACPI
1784 static const struct acpi_device_id ssif_acpi_match[] = {
1785         { "IPI0001", 0 },
1786         { },
1787 };
1788 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1789 #endif
1790
1791 #ifdef CONFIG_DMI
1792 static int dmi_ipmi_probe(struct platform_device *pdev)
1793 {
1794         u8 slave_addr = 0;
1795         u16 i2c_addr;
1796         int rv;
1797
1798         if (!ssif_trydmi)
1799                 return -ENODEV;
1800
1801         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
1802         if (rv) {
1803                 dev_warn(&pdev->dev, PFX "No i2c-addr property\n");
1804                 return -ENODEV;
1805         }
1806
1807         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
1808         if (rv)
1809                 dev_warn(&pdev->dev, "device has no slave-addr property");
1810
1811         return new_ssif_client(i2c_addr, NULL, 0,
1812                                slave_addr, SI_SMBIOS, &pdev->dev);
1813 }
1814 #else
1815 static int dmi_ipmi_probe(struct platform_device *pdev)
1816 {
1817         return -ENODEV;
1818 }
1819 #endif
1820
1821 static const struct i2c_device_id ssif_id[] = {
1822         { DEVICE_NAME, 0 },
1823         { }
1824 };
1825 MODULE_DEVICE_TABLE(i2c, ssif_id);
1826
1827 static struct i2c_driver ssif_i2c_driver = {
1828         .class          = I2C_CLASS_HWMON,
1829         .driver         = {
1830                 .name                   = DEVICE_NAME
1831         },
1832         .probe          = ssif_probe,
1833         .remove         = ssif_remove,
1834         .alert          = ssif_alert,
1835         .id_table       = ssif_id,
1836         .detect         = ssif_detect
1837 };
1838
1839 static int ssif_platform_probe(struct platform_device *dev)
1840 {
1841         return dmi_ipmi_probe(dev);
1842 }
1843
1844 static int ssif_platform_remove(struct platform_device *dev)
1845 {
1846         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
1847
1848         if (!addr_info)
1849                 return 0;
1850
1851         mutex_lock(&ssif_infos_mutex);
1852         i2c_unregister_device(addr_info->client);
1853
1854         list_del(&addr_info->link);
1855         kfree(addr_info);
1856         mutex_unlock(&ssif_infos_mutex);
1857         return 0;
1858 }
1859
1860 static struct platform_driver ipmi_driver = {
1861         .driver = {
1862                 .name = DEVICE_NAME,
1863         },
1864         .probe          = ssif_platform_probe,
1865         .remove         = ssif_platform_remove,
1866 };
1867
1868 static int init_ipmi_ssif(void)
1869 {
1870         int i;
1871         int rv;
1872
1873         if (initialized)
1874                 return 0;
1875
1876         pr_info("IPMI SSIF Interface driver\n");
1877
1878         /* build list for i2c from addr list */
1879         for (i = 0; i < num_addrs; i++) {
1880                 rv = new_ssif_client(addr[i], adapter_name[i],
1881                                      dbg[i], slave_addrs[i],
1882                                      SI_HARDCODED, NULL);
1883                 if (rv)
1884                         pr_err(PFX
1885                                "Couldn't add hardcoded device at addr 0x%x\n",
1886                                addr[i]);
1887         }
1888
1889         if (ssif_tryacpi)
1890                 ssif_i2c_driver.driver.acpi_match_table =
1891                         ACPI_PTR(ssif_acpi_match);
1892
1893         if (ssif_trydmi) {
1894                 rv = platform_driver_register(&ipmi_driver);
1895                 if (rv)
1896                         pr_err(PFX "Unable to register driver: %d\n", rv);
1897         }
1898
1899         ssif_i2c_driver.address_list = ssif_address_list();
1900
1901         rv = i2c_add_driver(&ssif_i2c_driver);
1902         if (!rv)
1903                 initialized = true;
1904
1905         return rv;
1906 }
1907 module_init(init_ipmi_ssif);
1908
1909 static void cleanup_ipmi_ssif(void)
1910 {
1911         if (!initialized)
1912                 return;
1913
1914         initialized = false;
1915
1916         i2c_del_driver(&ssif_i2c_driver);
1917
1918         platform_driver_unregister(&ipmi_driver);
1919
1920         free_ssif_clients();
1921 }
1922 module_exit(cleanup_ipmi_ssif);
1923
1924 MODULE_ALIAS("platform:dmi-ipmi-ssif");
1925 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
1926 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
1927 MODULE_LICENSE("GPL");