4 * The state machine for an Open IPMI BT sub-driver under ipmi_si.c, part
5 * of the driver architecture at http://sourceforge.net/project/openipmi
7 * Author: Rocky Craig <first.last@hp.com>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
14 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
16 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
20 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
22 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
23 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 * You should have received a copy of the GNU General Public License along
26 * with this program; if not, write to the Free Software Foundation, Inc.,
27 * 675 Mass Ave, Cambridge, MA 02139, USA. */
29 #include <linux/kernel.h> /* For printk. */
30 #include <linux/string.h>
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/ipmi_msgdefs.h> /* for completion codes */
34 #include "ipmi_si_sm.h"
36 static int bt_debug = 0x00; /* Production value 0, see following flags */
38 #define BT_DEBUG_ENABLE 1
39 #define BT_DEBUG_MSG 2
40 #define BT_DEBUG_STATES 4
41 module_param(bt_debug, int, 0644);
42 MODULE_PARM_DESC(bt_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
44 /* Typical "Get BT Capabilities" values are 2-3 retries, 5-10 seconds,
45 and 64 byte buffers. However, one HP implementation wants 255 bytes of
46 buffer (with a documented message of 160 bytes) so go for the max.
47 Since the Open IPMI architecture is single-message oriented at this
48 stage, the queue depth of BT is of no concern. */
50 #define BT_NORMAL_TIMEOUT 5000000 /* seconds in microseconds */
51 #define BT_RETRY_LIMIT 2
52 #define BT_RESET_DELAY 6000000 /* 6 seconds after warm reset */
56 BT_STATE_XACTION_START,
59 BT_STATE_WRITE_CONSUME,
62 BT_STATE_RESET1, /* These must come last */
71 enum bt_states last_state; /* assist printing and resets */
72 unsigned char seq; /* BT sequence number */
74 unsigned char write_data[IPMI_MAX_MSG_LENGTH];
76 unsigned char read_data[IPMI_MAX_MSG_LENGTH];
80 unsigned int error_retries; /* end of "common" fields */
81 int nonzero_status; /* hung BMCs stay all 0 */
84 #define BT_CLR_WR_PTR 0x01 /* See IPMI 1.5 table 11.6.4 */
85 #define BT_CLR_RD_PTR 0x02
86 #define BT_H2B_ATN 0x04
87 #define BT_B2H_ATN 0x08
88 #define BT_SMS_ATN 0x10
90 #define BT_H_BUSY 0x40
91 #define BT_B_BUSY 0x80
93 /* Some bits are toggled on each write: write once to set it, once
94 more to clear it; writing a zero does nothing. To absolutely
95 clear it, check its state and write if set. This avoids the "get
96 current then use as mask" scheme to modify one bit. Note that the
97 variable "bt" is hardcoded into these macros. */
99 #define BT_STATUS bt->io->inputb(bt->io, 0)
100 #define BT_CONTROL(x) bt->io->outputb(bt->io, 0, x)
102 #define BMC2HOST bt->io->inputb(bt->io, 1)
103 #define HOST2BMC(x) bt->io->outputb(bt->io, 1, x)
105 #define BT_INTMASK_R bt->io->inputb(bt->io, 2)
106 #define BT_INTMASK_W(x) bt->io->outputb(bt->io, 2, x)
108 /* Convenience routines for debugging. These are not multi-open safe!
109 Note the macros have hardcoded variables in them. */
111 static char *state2txt(unsigned char state)
114 case BT_STATE_IDLE: return("IDLE");
115 case BT_STATE_XACTION_START: return("XACTION");
116 case BT_STATE_WRITE_BYTES: return("WR_BYTES");
117 case BT_STATE_WRITE_END: return("WR_END");
118 case BT_STATE_WRITE_CONSUME: return("WR_CONSUME");
119 case BT_STATE_B2H_WAIT: return("B2H_WAIT");
120 case BT_STATE_READ_END: return("RD_END");
121 case BT_STATE_RESET1: return("RESET1");
122 case BT_STATE_RESET2: return("RESET2");
123 case BT_STATE_RESET3: return("RESET3");
124 case BT_STATE_RESTART: return("RESTART");
125 case BT_STATE_HOSED: return("HOSED");
129 #define STATE2TXT state2txt(bt->state)
131 static char *status2txt(unsigned char status, char *buf)
134 if (status & BT_B_BUSY) strcat(buf, "B_BUSY ");
135 if (status & BT_H_BUSY) strcat(buf, "H_BUSY ");
136 if (status & BT_OEM0) strcat(buf, "OEM0 ");
137 if (status & BT_SMS_ATN) strcat(buf, "SMS ");
138 if (status & BT_B2H_ATN) strcat(buf, "B2H ");
139 if (status & BT_H2B_ATN) strcat(buf, "H2B ");
143 #define STATUS2TXT(buf) status2txt(status, buf)
145 /* This will be called from within this module on a hosed condition */
147 static unsigned int bt_init_data(struct si_sm_data *bt, struct si_sm_io *io)
149 bt->state = BT_STATE_IDLE;
150 bt->last_state = BT_STATE_IDLE;
155 bt->error_retries = 0;
156 bt->nonzero_status = 0;
158 bt->timeout = BT_NORMAL_TIMEOUT;
159 return 3; /* We claim 3 bytes of space; ought to check SPMI table */
162 static int bt_start_transaction(struct si_sm_data *bt,
168 if ((size < 2) || (size > IPMI_MAX_MSG_LENGTH))
171 if ((bt->state != BT_STATE_IDLE) && (bt->state != BT_STATE_HOSED))
174 if (bt_debug & BT_DEBUG_MSG) {
175 printk(KERN_WARNING "+++++++++++++++++++++++++++++++++++++\n");
176 printk(KERN_WARNING "BT: write seq=0x%02X:", bt->seq);
177 for (i = 0; i < size; i ++)
178 printk (" %02x", data[i]);
181 bt->write_data[0] = size + 1; /* all data plus seq byte */
182 bt->write_data[1] = *data; /* NetFn/LUN */
183 bt->write_data[2] = bt->seq;
184 memcpy(bt->write_data + 3, data + 1, size - 1);
185 bt->write_count = size + 2;
187 bt->error_retries = 0;
188 bt->nonzero_status = 0;
191 bt->state = BT_STATE_XACTION_START;
192 bt->last_state = BT_STATE_IDLE;
193 bt->timeout = BT_NORMAL_TIMEOUT;
197 /* After the upper state machine has been told SI_SM_TRANSACTION_COMPLETE
198 it calls this. Strip out the length and seq bytes. */
200 static int bt_get_result(struct si_sm_data *bt,
206 msg_len = bt->read_count - 2; /* account for length & seq */
207 /* Always NetFn, Cmd, cCode */
208 if (msg_len < 3 || msg_len > IPMI_MAX_MSG_LENGTH) {
209 printk(KERN_DEBUG "BT results: bad msg_len = %d\n", msg_len);
210 data[0] = bt->write_data[1] | 0x4; /* Kludge a response */
211 data[1] = bt->write_data[3];
212 data[2] = IPMI_ERR_UNSPECIFIED;
215 data[0] = bt->read_data[1];
216 data[1] = bt->read_data[3];
217 if (length < msg_len)
219 if (bt->truncated) { /* can be set in read_all_bytes() */
220 data[2] = IPMI_ERR_MSG_TRUNCATED;
223 memcpy(data + 2, bt->read_data + 4, msg_len - 2);
225 if (bt_debug & BT_DEBUG_MSG) {
226 printk (KERN_WARNING "BT: res (raw)");
227 for (i = 0; i < msg_len; i++)
228 printk(" %02x", data[i]);
232 bt->read_count = 0; /* paranoia */
236 /* This bit's functionality is optional */
237 #define BT_BMC_HWRST 0x80
239 static void reset_flags(struct si_sm_data *bt)
241 if (BT_STATUS & BT_H_BUSY)
242 BT_CONTROL(BT_H_BUSY);
243 if (BT_STATUS & BT_B_BUSY)
244 BT_CONTROL(BT_B_BUSY);
245 BT_CONTROL(BT_CLR_WR_PTR);
246 BT_CONTROL(BT_SMS_ATN);
248 if (BT_STATUS & BT_B2H_ATN) {
250 BT_CONTROL(BT_H_BUSY);
251 BT_CONTROL(BT_B2H_ATN);
252 BT_CONTROL(BT_CLR_RD_PTR);
253 for (i = 0; i < IPMI_MAX_MSG_LENGTH + 2; i++)
255 BT_CONTROL(BT_H_BUSY);
259 static inline void write_all_bytes(struct si_sm_data *bt)
263 if (bt_debug & BT_DEBUG_MSG) {
264 printk(KERN_WARNING "BT: write %d bytes seq=0x%02X",
265 bt->write_count, bt->seq);
266 for (i = 0; i < bt->write_count; i++)
267 printk (" %02x", bt->write_data[i]);
270 for (i = 0; i < bt->write_count; i++)
271 HOST2BMC(bt->write_data[i]);
274 static inline int read_all_bytes(struct si_sm_data *bt)
278 bt->read_data[0] = BMC2HOST;
279 bt->read_count = bt->read_data[0];
280 if (bt_debug & BT_DEBUG_MSG)
281 printk(KERN_WARNING "BT: read %d bytes:", bt->read_count);
283 /* minimum: length, NetFn, Seq, Cmd, cCode == 5 total, or 4 more
284 following the length byte. */
285 if (bt->read_count < 4 || bt->read_count >= IPMI_MAX_MSG_LENGTH) {
286 if (bt_debug & BT_DEBUG_MSG)
287 printk("bad length %d\n", bt->read_count);
289 return 1; /* let next XACTION START clean it up */
291 for (i = 1; i <= bt->read_count; i++)
292 bt->read_data[i] = BMC2HOST;
293 bt->read_count++; /* account for the length byte */
295 if (bt_debug & BT_DEBUG_MSG) {
296 for (i = 0; i < bt->read_count; i++)
297 printk (" %02x", bt->read_data[i]);
300 if (bt->seq != bt->write_data[2]) /* idiot check */
301 printk(KERN_DEBUG "BT: internal error: sequence mismatch\n");
303 /* per the spec, the (NetFn, Seq, Cmd) tuples should match */
304 if ((bt->read_data[3] == bt->write_data[3]) && /* Cmd */
305 (bt->read_data[2] == bt->write_data[2]) && /* Sequence */
306 ((bt->read_data[1] & 0xF8) == (bt->write_data[1] & 0xF8)))
309 if (bt_debug & BT_DEBUG_MSG)
310 printk(KERN_WARNING "BT: bad packet: "
311 "want 0x(%02X, %02X, %02X) got (%02X, %02X, %02X)\n",
312 bt->write_data[1], bt->write_data[2], bt->write_data[3],
313 bt->read_data[1], bt->read_data[2], bt->read_data[3]);
317 /* Modifies bt->state appropriately, need to get into the bt_event() switch */
319 static void error_recovery(struct si_sm_data *bt, char *reason)
321 unsigned char status;
322 char buf[40]; /* For getting status */
324 bt->timeout = BT_NORMAL_TIMEOUT; /* various places want to retry */
327 printk(KERN_DEBUG "BT: %s in %s %s\n", reason, STATE2TXT,
330 (bt->error_retries)++;
331 if (bt->error_retries > BT_RETRY_LIMIT) {
332 printk(KERN_DEBUG "retry limit (%d) exceeded\n", BT_RETRY_LIMIT);
333 bt->state = BT_STATE_HOSED;
334 if (!bt->nonzero_status)
335 printk(KERN_ERR "IPMI: BT stuck, try power cycle\n");
336 else if (bt->seq == FIRST_SEQ + BT_RETRY_LIMIT) {
337 /* most likely during insmod */
338 printk(KERN_DEBUG "IPMI: BT reset (takes 5 secs)\n");
339 bt->state = BT_STATE_RESET1;
344 /* Sometimes the BMC queues get in an "off-by-one" state...*/
345 if ((bt->state == BT_STATE_B2H_WAIT) && (status & BT_B2H_ATN)) {
346 printk(KERN_DEBUG "retry B2H_WAIT\n");
350 printk(KERN_DEBUG "restart command\n");
351 bt->state = BT_STATE_RESTART;
354 /* Check the status and (possibly) advance the BT state machine. The
355 default return is SI_SM_CALL_WITH_DELAY. */
357 static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
359 unsigned char status;
360 char buf[40]; /* For getting status */
364 bt->nonzero_status |= status;
366 if ((bt_debug & BT_DEBUG_STATES) && (bt->state != bt->last_state))
367 printk(KERN_WARNING "BT: %s %s TO=%ld - %ld \n",
372 bt->last_state = bt->state;
374 if (bt->state == BT_STATE_HOSED)
377 if (bt->state != BT_STATE_IDLE) { /* do timeout test */
379 if ((bt->timeout < 0) && (bt->state < BT_STATE_RESET1)) {
380 error_recovery(bt, "timed out");
381 return SI_SM_CALL_WITHOUT_DELAY;
387 case BT_STATE_IDLE: /* check for asynchronous messages */
388 if (status & BT_SMS_ATN) {
389 BT_CONTROL(BT_SMS_ATN); /* clear it */
394 case BT_STATE_XACTION_START:
395 if (status & BT_H_BUSY) {
396 BT_CONTROL(BT_H_BUSY);
399 if (status & BT_B2H_ATN)
401 bt->state = BT_STATE_WRITE_BYTES;
402 return SI_SM_CALL_WITHOUT_DELAY; /* for logging */
404 case BT_STATE_WRITE_BYTES:
405 if (status & (BT_B_BUSY | BT_H2B_ATN))
407 BT_CONTROL(BT_CLR_WR_PTR);
409 BT_CONTROL(BT_H2B_ATN); /* clears too fast to catch? */
410 bt->state = BT_STATE_WRITE_CONSUME;
411 return SI_SM_CALL_WITHOUT_DELAY; /* it MIGHT sail through */
413 case BT_STATE_WRITE_CONSUME: /* BMCs usually blow right thru here */
414 if (status & (BT_H2B_ATN | BT_B_BUSY))
416 bt->state = BT_STATE_B2H_WAIT;
417 /* fall through with status */
419 /* Stay in BT_STATE_B2H_WAIT until a packet matches. However, spinning
420 hard here, constantly reading status, seems to hold off the
421 generation of B2H_ATN so ALWAYS return CALL_WITH_DELAY. */
423 case BT_STATE_B2H_WAIT:
424 if (!(status & BT_B2H_ATN))
427 /* Assume ordered, uncached writes: no need to wait */
428 if (!(status & BT_H_BUSY))
429 BT_CONTROL(BT_H_BUSY); /* set */
430 BT_CONTROL(BT_B2H_ATN); /* clear it, ACK to the BMC */
431 BT_CONTROL(BT_CLR_RD_PTR); /* reset the queue */
432 i = read_all_bytes(bt);
433 BT_CONTROL(BT_H_BUSY); /* clear */
434 if (!i) /* Try this state again */
436 bt->state = BT_STATE_READ_END;
437 return SI_SM_CALL_WITHOUT_DELAY; /* for logging */
439 case BT_STATE_READ_END:
441 /* I could wait on BT_H_BUSY to go clear for a truly clean
442 exit. However, this is already done in XACTION_START
443 and the (possible) extra loop/status/possible wait affects
444 performance. So, as long as it works, just ignore H_BUSY */
446 #ifdef MAKE_THIS_TRUE_IF_NECESSARY
448 if (status & BT_H_BUSY)
452 bt->state = BT_STATE_IDLE;
453 return SI_SM_TRANSACTION_COMPLETE;
455 case BT_STATE_RESET1:
457 bt->timeout = BT_RESET_DELAY;
458 bt->state = BT_STATE_RESET2;
461 case BT_STATE_RESET2: /* Send a soft reset */
462 BT_CONTROL(BT_CLR_WR_PTR);
463 HOST2BMC(3); /* number of bytes following */
464 HOST2BMC(0x18); /* NetFn/LUN == Application, LUN 0 */
465 HOST2BMC(42); /* Sequence number */
466 HOST2BMC(3); /* Cmd == Soft reset */
467 BT_CONTROL(BT_H2B_ATN);
468 bt->state = BT_STATE_RESET3;
471 case BT_STATE_RESET3:
473 return SI_SM_CALL_WITH_DELAY;
474 bt->state = BT_STATE_RESTART; /* printk in debug modes */
477 case BT_STATE_RESTART: /* don't reset retries! */
478 bt->write_data[2] = ++bt->seq;
480 bt->nonzero_status = 0;
481 bt->timeout = BT_NORMAL_TIMEOUT;
482 bt->state = BT_STATE_XACTION_START;
485 default: /* HOSED is supposed to be caught much earlier */
486 error_recovery(bt, "internal logic error");
489 return SI_SM_CALL_WITH_DELAY;
492 static int bt_detect(struct si_sm_data *bt)
494 /* It's impossible for the BT status and interrupt registers to be
495 all 1's, (assuming a properly functioning, self-initialized BMC)
496 but that's what you get from reading a bogus address, so we
497 test that first. The calling routine uses negative logic. */
499 if ((BT_STATUS == 0xFF) && (BT_INTMASK_R == 0xFF))
505 static void bt_cleanup(struct si_sm_data *bt)
509 static int bt_size(void)
511 return sizeof(struct si_sm_data);
514 struct si_sm_handlers bt_smi_handlers =
516 .init_data = bt_init_data,
517 .start_transaction = bt_start_transaction,
518 .get_result = bt_get_result,
521 .cleanup = bt_cleanup,