[net-next-2.6.git] / drivers / char / ipmi / ipmi_bt_sm.c

/*
 *  ipmi_bt_sm.c
 *
 *  The state machine for an Open IPMI BT sub-driver under ipmi_si.c, part
 *  of the driver architecture at http://sourceforge.net/project/openipmi
 *
 *  Author:	Rocky Craig <first.last@hp.com>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.  */

#include <linux/kernel.h> /* For printk. */
#include <linux/string.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ipmi_msgdefs.h>		/* for completion codes */
#include "ipmi_si_sm.h"

static int bt_debug = 0x00;	/* Production value 0, see following flags */

#define	BT_DEBUG_ENABLE	1
#define BT_DEBUG_MSG	2
#define BT_DEBUG_STATES	4
module_param(bt_debug, int, 0644);
MODULE_PARM_DESC(bt_debug, "debug bitmask, 1=enable, 2=messages, 4=states");

/* Typical "Get BT Capabilities" values are 2-3 retries, 5-10 seconds,
   and 64 byte buffers.  However, one HP implementation wants 255 bytes of
   buffer (with a documented message of 160 bytes) so go for the max.
   Since the Open IPMI architecture is single-message oriented at this
   stage, the queue depth of BT is of no concern. */

#define BT_NORMAL_TIMEOUT	5000000	/* seconds in microseconds */
#define BT_RETRY_LIMIT		2
#define BT_RESET_DELAY		6000000	/* 6 seconds after warm reset */

enum bt_states {
	BT_STATE_IDLE,
	BT_STATE_XACTION_START,
	BT_STATE_WRITE_BYTES,
	BT_STATE_WRITE_END,
	BT_STATE_WRITE_CONSUME,
	BT_STATE_B2H_WAIT,
	BT_STATE_READ_END,
	BT_STATE_RESET1,		/* These must come last */
	BT_STATE_RESET2,
	BT_STATE_RESET3,
	BT_STATE_RESTART,
	BT_STATE_HOSED
};

struct si_sm_data {
	enum bt_states	state;
	enum bt_states	last_state;	/* assist printing and resets */
	unsigned char	seq;		/* BT sequence number */
	struct si_sm_io	*io;
        unsigned char	write_data[IPMI_MAX_MSG_LENGTH];
        int		write_count;
        unsigned char	read_data[IPMI_MAX_MSG_LENGTH];
        int		read_count;
        int		truncated;
        long		timeout;
        unsigned int	error_retries;	/* end of "common" fields */
	int		nonzero_status;	/* hung BMCs stay all 0 */
};

#define BT_CLR_WR_PTR	0x01	/* See IPMI 1.5 table 11.6.4 */
#define BT_CLR_RD_PTR	0x02
#define BT_H2B_ATN	0x04
#define BT_B2H_ATN	0x08
#define BT_SMS_ATN	0x10
#define BT_OEM0		0x20
#define BT_H_BUSY	0x40
#define BT_B_BUSY	0x80

/* Some bits are toggled on each write: write once to set it, once
   more to clear it; writing a zero does nothing.  To absolutely
   clear it, check its state and write if set.  This avoids the "get
   current then use as mask" scheme to modify one bit.  Note that the
   variable "bt" is hardcoded into these macros. */

#define BT_STATUS	bt->io->inputb(bt->io, 0)
#define BT_CONTROL(x)	bt->io->outputb(bt->io, 0, x)

#define BMC2HOST	bt->io->inputb(bt->io, 1)
#define HOST2BMC(x)	bt->io->outputb(bt->io, 1, x)

#define BT_INTMASK_R	bt->io->inputb(bt->io, 2)
#define BT_INTMASK_W(x)	bt->io->outputb(bt->io, 2, x)

/* Convenience routines for debugging.  These are not multi-open safe!
   Note the macros have hardcoded variables in them. */

static char *state2txt(unsigned char state)
{
	switch (state) {
		case BT_STATE_IDLE:		return("IDLE");
		case BT_STATE_XACTION_START:	return("XACTION");
		case BT_STATE_WRITE_BYTES:	return("WR_BYTES");
		case BT_STATE_WRITE_END:	return("WR_END");
		case BT_STATE_WRITE_CONSUME:	return("WR_CONSUME");
		case BT_STATE_B2H_WAIT:		return("B2H_WAIT");
		case BT_STATE_READ_END:		return("RD_END");
		case BT_STATE_RESET1:		return("RESET1");
		case BT_STATE_RESET2:		return("RESET2");
		case BT_STATE_RESET3:		return("RESET3");
		case BT_STATE_RESTART:		return("RESTART");
		case BT_STATE_HOSED:		return("HOSED");
	}
	return("BAD STATE");
}
#define STATE2TXT state2txt(bt->state)

static char *status2txt(unsigned char status, char *buf)
{
	strcpy(buf, "[ ");
	if (status & BT_B_BUSY) strcat(buf, "B_BUSY ");
	if (status & BT_H_BUSY) strcat(buf, "H_BUSY ");
	if (status & BT_OEM0) strcat(buf, "OEM0 ");
	if (status & BT_SMS_ATN) strcat(buf, "SMS ");
	if (status & BT_B2H_ATN) strcat(buf, "B2H ");
	if (status & BT_H2B_ATN) strcat(buf, "H2B ");
	strcat(buf, "]");
	return buf;
}
#define STATUS2TXT(buf) status2txt(status, buf)

/* This will be called from within this module on a hosed condition */
#define FIRST_SEQ	0
static unsigned int bt_init_data(struct si_sm_data *bt, struct si_sm_io *io)
{
	bt->state = BT_STATE_IDLE;
	bt->last_state = BT_STATE_IDLE;
	bt->seq = FIRST_SEQ;
	bt->io = io;
	bt->write_count = 0;
	bt->read_count = 0;
	bt->error_retries = 0;
	bt->nonzero_status = 0;
	bt->truncated = 0;
	bt->timeout = BT_NORMAL_TIMEOUT;
	return 3; /* We claim 3 bytes of space; ought to check SPMI table */
}

static int bt_start_transaction(struct si_sm_data *bt,
				unsigned char *data,
				unsigned int size)
{
	unsigned int i;

	if ((size < 2) || (size > IPMI_MAX_MSG_LENGTH))
	       return -1;

	if ((bt->state != BT_STATE_IDLE) && (bt->state != BT_STATE_HOSED))
		return -2;

	if (bt_debug & BT_DEBUG_MSG) {
    		printk(KERN_WARNING "+++++++++++++++++++++++++++++++++++++\n");
		printk(KERN_WARNING "BT: write seq=0x%02X:", bt->seq);
		for (i = 0; i < size; i ++)
		       printk (" %02x", data[i]);
		printk("\n");
	}
	bt->write_data[0] = size + 1;	/* all data plus seq byte */
	bt->write_data[1] = *data;	/* NetFn/LUN */
	bt->write_data[2] = bt->seq;
	memcpy(bt->write_data + 3, data + 1, size - 1);
	bt->write_count = size + 2;

	bt->error_retries = 0;
	bt->nonzero_status = 0;
	bt->read_count = 0;
	bt->truncated = 0;
	bt->state = BT_STATE_XACTION_START;
	bt->last_state = BT_STATE_IDLE;
	bt->timeout = BT_NORMAL_TIMEOUT;
	return 0;
}

/* After the upper state machine has been told SI_SM_TRANSACTION_COMPLETE
   it calls this.  Strip out the length and seq bytes. */

static int bt_get_result(struct si_sm_data *bt,
			   unsigned char *data,
			   unsigned int length)
{
	int i, msg_len;

	msg_len = bt->read_count - 2;		/* account for length & seq */
	/* Always NetFn, Cmd, cCode */
	if (msg_len < 3 || msg_len > IPMI_MAX_MSG_LENGTH) {
		printk(KERN_DEBUG "BT results: bad msg_len = %d\n", msg_len);
		data[0] = bt->write_data[1] | 0x4;	/* Kludge a response */
		data[1] = bt->write_data[3];
		data[2] = IPMI_ERR_UNSPECIFIED;
		msg_len = 3;
	} else {
		data[0] = bt->read_data[1];
		data[1] = bt->read_data[3];
		if (length < msg_len)
		       bt->truncated = 1;
		if (bt->truncated) {	/* can be set in read_all_bytes() */
			data[2] = IPMI_ERR_MSG_TRUNCATED;
			msg_len = 3;
		} else
		       memcpy(data + 2, bt->read_data + 4, msg_len - 2);

		if (bt_debug & BT_DEBUG_MSG) {
			printk (KERN_WARNING "BT: res (raw)");
			for (i = 0; i < msg_len; i++)
			       printk(" %02x", data[i]);
			printk ("\n");
		}
	}
	bt->read_count = 0;	/* paranoia */
	return msg_len;
}

/* This bit's functionality is optional */
#define BT_BMC_HWRST	0x80

static void reset_flags(struct si_sm_data *bt)
{
	if (BT_STATUS & BT_H_BUSY)
	       BT_CONTROL(BT_H_BUSY);
	if (BT_STATUS & BT_B_BUSY)
	       BT_CONTROL(BT_B_BUSY);
	BT_CONTROL(BT_CLR_WR_PTR);
	BT_CONTROL(BT_SMS_ATN);

	if (BT_STATUS & BT_B2H_ATN) {
		int i;
		BT_CONTROL(BT_H_BUSY);
		BT_CONTROL(BT_B2H_ATN);
		BT_CONTROL(BT_CLR_RD_PTR);
		for (i = 0; i < IPMI_MAX_MSG_LENGTH + 2; i++)
		       BMC2HOST;
		BT_CONTROL(BT_H_BUSY);
	}
}

static inline void write_all_bytes(struct si_sm_data *bt)
{
	int i;

	if (bt_debug & BT_DEBUG_MSG) {
    		printk(KERN_WARNING "BT: write %d bytes seq=0x%02X",
			bt->write_count, bt->seq);
		for (i = 0; i < bt->write_count; i++)
			printk (" %02x", bt->write_data[i]);
		printk ("\n");
	}
	for (i = 0; i < bt->write_count; i++)
	       HOST2BMC(bt->write_data[i]);
}

static inline int read_all_bytes(struct si_sm_data *bt)
{
	unsigned char i;

	bt->read_data[0] = BMC2HOST;
	bt->read_count = bt->read_data[0];
	if (bt_debug & BT_DEBUG_MSG)
    		printk(KERN_WARNING "BT: read %d bytes:", bt->read_count);

	/* minimum: length, NetFn, Seq, Cmd, cCode == 5 total, or 4 more
	   following the length byte. */
	if (bt->read_count < 4 || bt->read_count >= IPMI_MAX_MSG_LENGTH) {
		if (bt_debug & BT_DEBUG_MSG)
			printk("bad length %d\n", bt->read_count);
		bt->truncated = 1;
		return 1;	/* let next XACTION START clean it up */
	}
	for (i = 1; i <= bt->read_count; i++)
	       bt->read_data[i] = BMC2HOST;
	bt->read_count++;	/* account for the length byte */

	if (bt_debug & BT_DEBUG_MSG) {
	    	for (i = 0; i < bt->read_count; i++)
			printk (" %02x", bt->read_data[i]);
	    	printk ("\n");
	}
	if (bt->seq != bt->write_data[2])	/* idiot check */
		printk(KERN_DEBUG "BT: internal error: sequence mismatch\n");

	/* per the spec, the (NetFn, Seq, Cmd) tuples should match */
	if ((bt->read_data[3] == bt->write_data[3]) &&		/* Cmd */
        	(bt->read_data[2] == bt->write_data[2]) &&	/* Sequence */
        	((bt->read_data[1] & 0xF8) == (bt->write_data[1] & 0xF8)))
			return 1;

	if (bt_debug & BT_DEBUG_MSG)
	       printk(KERN_WARNING "BT: bad packet: "
		"want 0x(%02X, %02X, %02X) got (%02X, %02X, %02X)\n",
		bt->write_data[1], bt->write_data[2], bt->write_data[3],
		bt->read_data[1],  bt->read_data[2],  bt->read_data[3]);
	return 0;
}

/* Modifies bt->state appropriately, need to get into the bt_event() switch */

static void error_recovery(struct si_sm_data *bt, char *reason)
{
	unsigned char status;
	char buf[40]; /* For getting status */

	bt->timeout = BT_NORMAL_TIMEOUT; /* various places want to retry */

	status = BT_STATUS;
	printk(KERN_DEBUG "BT: %s in %s %s\n", reason, STATE2TXT,
	       STATUS2TXT(buf));

	(bt->error_retries)++;
	if (bt->error_retries > BT_RETRY_LIMIT) {
		printk(KERN_DEBUG "retry limit (%d) exceeded\n", BT_RETRY_LIMIT);
		bt->state = BT_STATE_HOSED;
		if (!bt->nonzero_status)
			printk(KERN_ERR "IPMI: BT stuck, try power cycle\n");
		else if (bt->seq == FIRST_SEQ + BT_RETRY_LIMIT) {
			/* most likely during insmod */
			printk(KERN_DEBUG "IPMI: BT reset (takes 5 secs)\n");
        		bt->state = BT_STATE_RESET1;
		}
	return;
	}

	/* Sometimes the BMC queues get in an "off-by-one" state...*/
	if ((bt->state == BT_STATE_B2H_WAIT) && (status & BT_B2H_ATN)) {
    		printk(KERN_DEBUG "retry B2H_WAIT\n");
		return;
	}

	printk(KERN_DEBUG "restart command\n");
	bt->state = BT_STATE_RESTART;
}

/* Check the status and (possibly) advance the BT state machine.  The
   default return is SI_SM_CALL_WITH_DELAY. */

static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
{
	unsigned char status;
	char buf[40]; /* For getting status */
	int i;

	status = BT_STATUS;
	bt->nonzero_status |= status;

	if ((bt_debug & BT_DEBUG_STATES) && (bt->state != bt->last_state))
		printk(KERN_WARNING "BT: %s %s TO=%ld - %ld \n",
			STATE2TXT,
			STATUS2TXT(buf),
			bt->timeout,
			time);
	bt->last_state = bt->state;

	if (bt->state == BT_STATE_HOSED)
	       return SI_SM_HOSED;

	if (bt->state != BT_STATE_IDLE) {	/* do timeout test */
		bt->timeout -= time;
		if ((bt->timeout < 0) && (bt->state < BT_STATE_RESET1)) {
			error_recovery(bt, "timed out");
			return SI_SM_CALL_WITHOUT_DELAY;
		}
	}

	switch (bt->state) {

    	case BT_STATE_IDLE:	/* check for asynchronous messages */
		if (status & BT_SMS_ATN) {
			BT_CONTROL(BT_SMS_ATN);	/* clear it */
			return SI_SM_ATTN;
		}
		return SI_SM_IDLE;

	case BT_STATE_XACTION_START:
		if (status & BT_H_BUSY) {
			BT_CONTROL(BT_H_BUSY);
			break;
		}
    		if (status & BT_B2H_ATN)
		       break;
		bt->state = BT_STATE_WRITE_BYTES;
		return SI_SM_CALL_WITHOUT_DELAY;	/* for logging */

	case BT_STATE_WRITE_BYTES:
		if (status & (BT_B_BUSY | BT_H2B_ATN))
		       break;
		BT_CONTROL(BT_CLR_WR_PTR);
		write_all_bytes(bt);
		BT_CONTROL(BT_H2B_ATN);	/* clears too fast to catch? */
		bt->state = BT_STATE_WRITE_CONSUME;
		return SI_SM_CALL_WITHOUT_DELAY; /* it MIGHT sail through */

	case BT_STATE_WRITE_CONSUME: /* BMCs usually blow right thru here */
        	if (status & (BT_H2B_ATN | BT_B_BUSY))
		       break;
		bt->state = BT_STATE_B2H_WAIT;
		/* fall through with status */

	/* Stay in BT_STATE_B2H_WAIT until a packet matches.  However, spinning
	   hard here, constantly reading status, seems to hold off the
	   generation of B2H_ATN so ALWAYS return CALL_WITH_DELAY. */

	case BT_STATE_B2H_WAIT:
    		if (!(status & BT_B2H_ATN))
		       break;

		/* Assume ordered, uncached writes: no need to wait */
		if (!(status & BT_H_BUSY))
		       BT_CONTROL(BT_H_BUSY); /* set */
		BT_CONTROL(BT_B2H_ATN);		/* clear it, ACK to the BMC */
		BT_CONTROL(BT_CLR_RD_PTR);	/* reset the queue */
		i = read_all_bytes(bt);
		BT_CONTROL(BT_H_BUSY);		/* clear */
		if (!i)				/* Try this state again */
		       break;
		bt->state = BT_STATE_READ_END;
		return SI_SM_CALL_WITHOUT_DELAY;	/* for logging */

    	case BT_STATE_READ_END:

		/* I could wait on BT_H_BUSY to go clear for a truly clean
		   exit.  However, this is already done in XACTION_START
		   and the (possible) extra loop/status/possible wait affects
		   performance.  So, as long as it works, just ignore H_BUSY */

#ifdef MAKE_THIS_TRUE_IF_NECESSARY

		if (status & BT_H_BUSY)
		       break;
#endif
		bt->seq++;
		bt->state = BT_STATE_IDLE;
		return SI_SM_TRANSACTION_COMPLETE;

	case BT_STATE_RESET1:
    		reset_flags(bt);
    		bt->timeout = BT_RESET_DELAY;
		bt->state = BT_STATE_RESET2;
		break;

	case BT_STATE_RESET2:		/* Send a soft reset */
		BT_CONTROL(BT_CLR_WR_PTR);
		HOST2BMC(3);		/* number of bytes following */
		HOST2BMC(0x18);		/* NetFn/LUN == Application, LUN 0 */
		HOST2BMC(42);		/* Sequence number */
		HOST2BMC(3);		/* Cmd == Soft reset */
		BT_CONTROL(BT_H2B_ATN);
		bt->state = BT_STATE_RESET3;
		break;

	case BT_STATE_RESET3:
		if (bt->timeout > 0)
		       return SI_SM_CALL_WITH_DELAY;
		bt->state = BT_STATE_RESTART;	/* printk in debug modes */
		break;

	case BT_STATE_RESTART:		/* don't reset retries! */
		bt->write_data[2] = ++bt->seq;
		bt->read_count = 0;
		bt->nonzero_status = 0;
		bt->timeout = BT_NORMAL_TIMEOUT;
		bt->state = BT_STATE_XACTION_START;
		break;

	default:	/* HOSED is supposed to be caught much earlier */
		error_recovery(bt, "internal logic error");
		break;
  	}
  	return SI_SM_CALL_WITH_DELAY;
}

static int bt_detect(struct si_sm_data *bt)
{
	/* It's impossible for the BT status and interrupt registers to be
	   all 1's, (assuming a properly functioning, self-initialized BMC)
	   but that's what you get from reading a bogus address, so we
	   test that first.  The calling routine uses negative logic. */

	if ((BT_STATUS == 0xFF) && (BT_INTMASK_R == 0xFF))
	       return 1;
	reset_flags(bt);
	return 0;
}

static void bt_cleanup(struct si_sm_data *bt)
{
}

static int bt_size(void)
{
	return sizeof(struct si_sm_data);
}

struct si_sm_handlers bt_smi_handlers =
{
	.init_data         = bt_init_data,
	.start_transaction = bt_start_transaction,
	.get_result        = bt_get_result,
	.event             = bt_event,
	.detect            = bt_detect,
	.cleanup           = bt_cleanup,
	.size              = bt_size,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ipmi_bt_sm.c
	3	*
	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
	6	*
	7	* Author: Rocky Craig <first.last@hp.com>
	8	*
	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.
	13	*
	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.
	24	*
	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. */
	28
	29	#include <linux/kernel.h> /* For printk. */
	30	#include <linux/string.h>
c4edff1c CM	31	#include <linux/module.h>
c4edff1c CM	32	#include <linux/moduleparam.h>
1da177e4 LT	33	#include <linux/ipmi_msgdefs.h> /* for completion codes */
	34	#include "ipmi_si_sm.h"
	35
1da177e4 LT	36	static int bt_debug = 0x00; /* Production value 0, see following flags */
	37
	38	#define BT_DEBUG_ENABLE 1
	39	#define BT_DEBUG_MSG 2
	40	#define BT_DEBUG_STATES 4
c4edff1c CM	41	module_param(bt_debug, int, 0644);
c4edff1c CM	42	MODULE_PARM_DESC(bt_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
1da177e4 LT	43
	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. */
	49
c4edff1c	50	#define BT_NORMAL_TIMEOUT 5000000 /* seconds in microseconds */
1da177e4 LT	51	#define BT_RETRY_LIMIT 2
	52	#define BT_RESET_DELAY 6000000 /* 6 seconds after warm reset */
	53
	54	enum bt_states {
	55	BT_STATE_IDLE,
	56	BT_STATE_XACTION_START,
	57	BT_STATE_WRITE_BYTES,
	58	BT_STATE_WRITE_END,
	59	BT_STATE_WRITE_CONSUME,
	60	BT_STATE_B2H_WAIT,
	61	BT_STATE_READ_END,
	62	BT_STATE_RESET1, /* These must come last */
	63	BT_STATE_RESET2,
	64	BT_STATE_RESET3,
	65	BT_STATE_RESTART,
	66	BT_STATE_HOSED
	67	};
	68
	69	struct si_sm_data {
	70	enum bt_states state;
	71	enum bt_states last_state; /* assist printing and resets */
	72	unsigned char seq; /* BT sequence number */
	73	struct si_sm_io *io;
	74	unsigned char write_data[IPMI_MAX_MSG_LENGTH];
	75	int write_count;
	76	unsigned char read_data[IPMI_MAX_MSG_LENGTH];
	77	int read_count;
	78	int truncated;
	79	long timeout;
	80	unsigned int error_retries; /* end of "common" fields */
	81	int nonzero_status; /* hung BMCs stay all 0 */
	82	};
	83
	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
	89	#define BT_OEM0 0x20
	90	#define BT_H_BUSY 0x40
	91	#define BT_B_BUSY 0x80
	92
	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. */
	98
	99	#define BT_STATUS bt->io->inputb(bt->io, 0)
	100	#define BT_CONTROL(x) bt->io->outputb(bt->io, 0, x)
	101
	102	#define BMC2HOST bt->io->inputb(bt->io, 1)
	103	#define HOST2BMC(x) bt->io->outputb(bt->io, 1, x)
	104
	105	#define BT_INTMASK_R bt->io->inputb(bt->io, 2)
	106	#define BT_INTMASK_W(x) bt->io->outputb(bt->io, 2, x)
	107
	108	/* Convenience routines for debugging. These are not multi-open safe!
	109	Note the macros have hardcoded variables in them. */
	110
	111	static char *state2txt(unsigned char state)
	112	{
	113	switch (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");
126	}
127	return("BAD STATE");
128	}
129	#define STATE2TXT state2txt(bt->state)
130
131	static char status2txt(unsigned char status, char buf)
132	{
133	strcpy(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 ");
140	strcat(buf, "]");
141	return buf;
142	}
143	#define STATUS2TXT(buf) status2txt(status, buf)
144
145	/* This will be called from within this module on a hosed condition */
146	#define FIRST_SEQ 0
147	static unsigned int bt_init_data(struct si_sm_data bt, struct si_sm_io io)
148	{
149	bt->state = BT_STATE_IDLE;
150	bt->last_state = BT_STATE_IDLE;
151	bt->seq = FIRST_SEQ;
152	bt->io = io;
153	bt->write_count = 0;
154	bt->read_count = 0;
155	bt->error_retries = 0;
156	bt->nonzero_status = 0;
157	bt->truncated = 0;
158	bt->timeout = BT_NORMAL_TIMEOUT;
159	return 3; /* We claim 3 bytes of space; ought to check SPMI table */
160	}
161
162	static int bt_start_transaction(struct si_sm_data *bt,
163	unsigned char *data,
164	unsigned int size)
165	{
166	unsigned int i;
167
e8b33617 CM	168	if ((size < 2) \|\| (size > IPMI_MAX_MSG_LENGTH))
e8b33617 CM	169	return -1;
1da177e4 LT	170
	171	if ((bt->state != BT_STATE_IDLE) && (bt->state != BT_STATE_HOSED))
	172	return -2;
	173
	174	if (bt_debug & BT_DEBUG_MSG) {
	175	printk(KERN_WARNING "+++++++++++++++++++++++++++++++++++++\n");
	176	printk(KERN_WARNING "BT: write seq=0x%02X:", bt->seq);
e8b33617 CM	177	for (i = 0; i < size; i ++)
e8b33617 CM	178	printk (" %02x", data[i]);
1da177e4 LT	179	printk("\n");
	180	}
	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;
	186
	187	bt->error_retries = 0;
	188	bt->nonzero_status = 0;
	189	bt->read_count = 0;
	190	bt->truncated = 0;
	191	bt->state = BT_STATE_XACTION_START;
	192	bt->last_state = BT_STATE_IDLE;
	193	bt->timeout = BT_NORMAL_TIMEOUT;
	194	return 0;
	195	}
	196
	197	/* After the upper state machine has been told SI_SM_TRANSACTION_COMPLETE
	198	it calls this. Strip out the length and seq bytes. */
	199
	200	static int bt_get_result(struct si_sm_data *bt,
	201	unsigned char *data,
	202	unsigned int length)
	203	{
	204	int i, msg_len;
	205
	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) {
c4edff1c	209	printk(KERN_DEBUG "BT results: bad msg_len = %d\n", msg_len);
1da177e4 LT	210	data[0] = bt->write_data[1] \| 0x4; /* Kludge a response */
	211	data[1] = bt->write_data[3];
	212	data[2] = IPMI_ERR_UNSPECIFIED;
	213	msg_len = 3;
	214	} else {
	215	data[0] = bt->read_data[1];
	216	data[1] = bt->read_data[3];
e8b33617 CM	217	if (length < msg_len)
e8b33617 CM	218	bt->truncated = 1;
1da177e4 LT	219	if (bt->truncated) { /* can be set in read_all_bytes() */
	220	data[2] = IPMI_ERR_MSG_TRUNCATED;
	221	msg_len = 3;
e8b33617 CM	222	} else
e8b33617 CM	223	memcpy(data + 2, bt->read_data + 4, msg_len - 2);
1da177e4 LT	224
	225	if (bt_debug & BT_DEBUG_MSG) {
	226	printk (KERN_WARNING "BT: res (raw)");
e8b33617 CM	227	for (i = 0; i < msg_len; i++)
e8b33617 CM	228	printk(" %02x", data[i]);
1da177e4 LT	229	printk ("\n");
	230	}
	231	}
	232	bt->read_count = 0; /* paranoia */
	233	return msg_len;
	234	}
	235
	236	/* This bit's functionality is optional */
	237	#define BT_BMC_HWRST 0x80
	238
	239	static void reset_flags(struct si_sm_data *bt)
	240	{
e8b33617 CM	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);
1da177e4 LT	245	BT_CONTROL(BT_CLR_WR_PTR);
1da177e4 LT	246	BT_CONTROL(BT_SMS_ATN);
c4edff1c	247
1da177e4 LT	248	if (BT_STATUS & BT_B2H_ATN) {
	249	int i;
	250	BT_CONTROL(BT_H_BUSY);
	251	BT_CONTROL(BT_B2H_ATN);
	252	BT_CONTROL(BT_CLR_RD_PTR);
e8b33617 CM	253	for (i = 0; i < IPMI_MAX_MSG_LENGTH + 2; i++)
e8b33617 CM	254	BMC2HOST;
1da177e4 LT	255	BT_CONTROL(BT_H_BUSY);
1da177e4 LT	256	}
1da177e4 LT	257	}
	258
	259	static inline void write_all_bytes(struct si_sm_data *bt)
	260	{
	261	int i;
	262
	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]);
	268	printk ("\n");
	269	}
e8b33617 CM	270	for (i = 0; i < bt->write_count; i++)
e8b33617 CM	271	HOST2BMC(bt->write_data[i]);
1da177e4 LT	272	}
	273
	274	static inline int read_all_bytes(struct si_sm_data *bt)
	275	{
	276	unsigned char i;
	277
	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);
	282
	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);
	288	bt->truncated = 1;
	289	return 1; /* let next XACTION START clean it up */
	290	}
e8b33617 CM	291	for (i = 1; i <= bt->read_count; i++)
e8b33617 CM	292	bt->read_data[i] = BMC2HOST;
1da177e4 LT	293	bt->read_count++; /* account for the length byte */
	294
	295	if (bt_debug & BT_DEBUG_MSG) {
	296	for (i = 0; i < bt->read_count; i++)
	297	printk (" %02x", bt->read_data[i]);
	298	printk ("\n");
	299	}
	300	if (bt->seq != bt->write_data[2]) /* idiot check */
c4edff1c	301	printk(KERN_DEBUG "BT: internal error: sequence mismatch\n");
1da177e4 LT	302
	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)))
	307	return 1;
	308
e8b33617 CM	309	if (bt_debug & BT_DEBUG_MSG)
e8b33617 CM	310	printk(KERN_WARNING "BT: bad packet: "
1da177e4 LT	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]);
	314	return 0;
	315	}
	316
	317	/* Modifies bt->state appropriately, need to get into the bt_event() switch */
	318
	319	static void error_recovery(struct si_sm_data bt, char reason)
	320	{
	321	unsigned char status;
	322	char buf[40]; /* For getting status */
	323
	324	bt->timeout = BT_NORMAL_TIMEOUT; /* various places want to retry */
	325
	326	status = BT_STATUS;
c4edff1c	327	printk(KERN_DEBUG "BT: %s in %s %s\n", reason, STATE2TXT,
1da177e4 LT	328	STATUS2TXT(buf));
	329
	330	(bt->error_retries)++;
	331	if (bt->error_retries > BT_RETRY_LIMIT) {
c4edff1c	332	printk(KERN_DEBUG "retry limit (%d) exceeded\n", BT_RETRY_LIMIT);
1da177e4 LT	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 */
c4edff1c	338	printk(KERN_DEBUG "IPMI: BT reset (takes 5 secs)\n");
1da177e4 LT	339	bt->state = BT_STATE_RESET1;
	340	}
	341	return;
	342	}
	343
	344	/* Sometimes the BMC queues get in an "off-by-one" state...*/
	345	if ((bt->state == BT_STATE_B2H_WAIT) && (status & BT_B2H_ATN)) {
c4edff1c	346	printk(KERN_DEBUG "retry B2H_WAIT\n");
1da177e4 LT	347	return;
	348	}
	349
c4edff1c	350	printk(KERN_DEBUG "restart command\n");
1da177e4 LT	351	bt->state = BT_STATE_RESTART;
	352	}
	353
	354	/* Check the status and (possibly) advance the BT state machine. The
	355	default return is SI_SM_CALL_WITH_DELAY. */
	356
	357	static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
	358	{
	359	unsigned char status;
	360	char buf[40]; /* For getting status */
	361	int i;
	362
	363	status = BT_STATUS;
	364	bt->nonzero_status \|= status;
	365
	366	if ((bt_debug & BT_DEBUG_STATES) && (bt->state != bt->last_state))
	367	printk(KERN_WARNING "BT: %s %s TO=%ld - %ld \n",
	368	STATE2TXT,
	369	STATUS2TXT(buf),
	370	bt->timeout,
	371	time);
	372	bt->last_state = bt->state;
	373
e8b33617 CM	374	if (bt->state == BT_STATE_HOSED)
e8b33617 CM	375	return SI_SM_HOSED;
1da177e4 LT	376
1da177e4 LT	377	if (bt->state != BT_STATE_IDLE) { /* do timeout test */
1da177e4 LT	378	bt->timeout -= time;
	379	if ((bt->timeout < 0) && (bt->state < BT_STATE_RESET1)) {
	380	error_recovery(bt, "timed out");
	381	return SI_SM_CALL_WITHOUT_DELAY;
	382	}
	383	}
	384
	385	switch (bt->state) {
	386
	387	case BT_STATE_IDLE: /* check for asynchronous messages */
	388	if (status & BT_SMS_ATN) {
	389	BT_CONTROL(BT_SMS_ATN); /* clear it */
	390	return SI_SM_ATTN;
	391	}
	392	return SI_SM_IDLE;
	393
	394	case BT_STATE_XACTION_START:
	395	if (status & BT_H_BUSY) {
	396	BT_CONTROL(BT_H_BUSY);
	397	break;
	398	}
e8b33617 CM	399	if (status & BT_B2H_ATN)
e8b33617 CM	400	break;
1da177e4 LT	401	bt->state = BT_STATE_WRITE_BYTES;
	402	return SI_SM_CALL_WITHOUT_DELAY; /* for logging */
	403
	404	case BT_STATE_WRITE_BYTES:
e8b33617 CM	405	if (status & (BT_B_BUSY \| BT_H2B_ATN))
e8b33617 CM	406	break;
1da177e4 LT	407	BT_CONTROL(BT_CLR_WR_PTR);
	408	write_all_bytes(bt);
	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 */
	412
	413	case BT_STATE_WRITE_CONSUME: /* BMCs usually blow right thru here */
e8b33617 CM	414	if (status & (BT_H2B_ATN \| BT_B_BUSY))
e8b33617 CM	415	break;
1da177e4 LT	416	bt->state = BT_STATE_B2H_WAIT;
	417	/* fall through with status */
	418
	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. */
	422
	423	case BT_STATE_B2H_WAIT:
e8b33617 CM	424	if (!(status & BT_B2H_ATN))
e8b33617 CM	425	break;
1da177e4 LT	426
1da177e4 LT	427	/* Assume ordered, uncached writes: no need to wait */
e8b33617 CM	428	if (!(status & BT_H_BUSY))
e8b33617 CM	429	BT_CONTROL(BT_H_BUSY); /* set */
1da177e4 LT	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 */
e8b33617 CM	434	if (!i) /* Try this state again */
e8b33617 CM	435	break;
1da177e4 LT	436	bt->state = BT_STATE_READ_END;
	437	return SI_SM_CALL_WITHOUT_DELAY; /* for logging */
	438
	439	case BT_STATE_READ_END:
	440
	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 */
	445
	446	#ifdef MAKE_THIS_TRUE_IF_NECESSARY
	447
e8b33617 CM	448	if (status & BT_H_BUSY)
e8b33617 CM	449	break;
1da177e4 LT	450	#endif
	451	bt->seq++;
	452	bt->state = BT_STATE_IDLE;
	453	return SI_SM_TRANSACTION_COMPLETE;
	454
	455	case BT_STATE_RESET1:
	456	reset_flags(bt);
	457	bt->timeout = BT_RESET_DELAY;
	458	bt->state = BT_STATE_RESET2;
	459	break;
	460
	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;
	469	break;
	470
	471	case BT_STATE_RESET3:
e8b33617 CM	472	if (bt->timeout > 0)
e8b33617 CM	473	return SI_SM_CALL_WITH_DELAY;
1da177e4 LT	474	bt->state = BT_STATE_RESTART; /* printk in debug modes */
	475	break;
	476
	477	case BT_STATE_RESTART: /* don't reset retries! */
	478	bt->write_data[2] = ++bt->seq;
	479	bt->read_count = 0;
	480	bt->nonzero_status = 0;
	481	bt->timeout = BT_NORMAL_TIMEOUT;
	482	bt->state = BT_STATE_XACTION_START;
	483	break;
	484
	485	default: /* HOSED is supposed to be caught much earlier */
	486	error_recovery(bt, "internal logic error");
	487	break;
	488	}
	489	return SI_SM_CALL_WITH_DELAY;
	490	}
	491
	492	static int bt_detect(struct si_sm_data *bt)
	493	{
	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. */
	498
e8b33617 CM	499	if ((BT_STATUS == 0xFF) && (BT_INTMASK_R == 0xFF))
e8b33617 CM	500	return 1;
1da177e4 LT	501	reset_flags(bt);
	502	return 0;
	503	}
	504
	505	static void bt_cleanup(struct si_sm_data *bt)
	506	{
	507	}
	508
	509	static int bt_size(void)
	510	{
	511	return sizeof(struct si_sm_data);
	512	}
	513
	514	struct si_sm_handlers bt_smi_handlers =
	515	{
1da177e4 LT	516	.init_data = bt_init_data,
	517	.start_transaction = bt_start_transaction,
	518	.get_result = bt_get_result,
	519	.event = bt_event,
	520	.detect = bt_detect,
	521	.cleanup = bt_cleanup,
	522	.size = bt_size,
	523	};