ipmi_bt_sm.c

来自「linux 内核源代码」· C语言 代码 · 共 671 行 · 第 1/2 页

{
	unsigned char i;

	/* length is "framing info", minimum = 4: NetFn, Seq, Cmd, cCode.
	   Keep layout of first four bytes aligned with write_data[] */

	bt->read_data[0] = BMC2HOST;
	bt->read_count = bt->read_data[0];

	if (bt->read_count < 4 || bt->read_count >= IPMI_MAX_MSG_LENGTH) {
		if (bt_debug & BT_DEBUG_MSG)
			printk(KERN_WARNING "BT: bad raw rsp len=%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 internally for length byte */

	if (bt_debug & BT_DEBUG_MSG) {
		int max = bt->read_count;

		printk(KERN_WARNING "BT: got %d bytes seq=0x%02X",
			max, bt->read_data[2]);
		if (max > 16)
			max = 16;
		for (i = 0; i < max; i++)
			printk (" %02x", bt->read_data[i]);
		printk ("%s\n", bt->read_count == max ? "" : " ...");
	}

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

	if (bt_debug & BT_DEBUG_MSG)
		printk(KERN_WARNING "IPMI BT: bad packet: "
		"want 0x(%02X, %02X, %02X) got (%02X, %02X, %02X)\n",
		bt->write_data[1] | 0x04, bt->write_data[2], bt->write_data[3],
		bt->read_data[1],  bt->read_data[2],  bt->read_data[3]);
	return 0;
}

/* Restart if retries are left, or return an error completion code */

static enum si_sm_result error_recovery(struct si_sm_data *bt,
					unsigned char status,
					unsigned char cCode)
{
	char *reason;

	bt->timeout = bt->BT_CAP_req2rsp;

	switch (cCode) {
	case IPMI_TIMEOUT_ERR:
		reason = "timeout";
		break;
	default:
		reason = "internal error";
		break;
	}

	printk(KERN_WARNING "IPMI BT: %s in %s %s ", 	/* open-ended line */
		reason, STATE2TXT, STATUS2TXT);

	/* Per the IPMI spec, retries are based on the sequence number
	   known only to this module, so manage a restart here. */
	(bt->error_retries)++;
	if (bt->error_retries < bt->BT_CAP_retries) {
		printk("%d retries left\n",
			bt->BT_CAP_retries - bt->error_retries);
		bt->state = BT_STATE_RESTART;
		return SI_SM_CALL_WITHOUT_DELAY;
	}

	printk("failed %d retries, sending error response\n",
		bt->BT_CAP_retries);
	if (!bt->nonzero_status)
		printk(KERN_ERR "IPMI BT: stuck, try power cycle\n");

	/* this is most likely during insmod */
	else if (bt->seq <= (unsigned char)(bt->BT_CAP_retries & 0xFF)) {
		printk(KERN_WARNING "IPMI: BT reset (takes 5 secs)\n");
		bt->state = BT_STATE_RESET1;
		return SI_SM_CALL_WITHOUT_DELAY;
	}

	/* Concoct a useful error message, set up the next state, and
	   be done with this sequence. */

	bt->state = BT_STATE_IDLE;
	switch (cCode) {
	case IPMI_TIMEOUT_ERR:
		if (status & BT_B_BUSY) {
			cCode = IPMI_NODE_BUSY_ERR;
			bt->state = BT_STATE_LONG_BUSY;
		}
		break;
	default:
		break;
	}
	force_result(bt, cCode);
	return SI_SM_TRANSACTION_COMPLETE;
}

/* Check status and (usually) take action and change this state machine. */

static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
{
	unsigned char status, BT_CAP[8];
	static enum bt_states last_printed = BT_STATE_PRINTME;
	int i;

	status = BT_STATUS;
	bt->nonzero_status |= status;
	if ((bt_debug & BT_DEBUG_STATES) && (bt->state != last_printed)) {
		printk(KERN_WARNING "BT: %s %s TO=%ld - %ld \n",
			STATE2TXT,
			STATUS2TXT,
			bt->timeout,
			time);
		last_printed = bt->state;
	}

	/* Commands that time out may still (eventually) provide a response.
	   This stale response will get in the way of a new response so remove
	   it if possible (hopefully during IDLE).  Even if it comes up later
	   it will be rejected by its (now-forgotten) seq number. */

	if ((bt->state < BT_STATE_WRITE_BYTES) && (status & BT_B2H_ATN)) {
		drain_BMC2HOST(bt);
		BT_SI_SM_RETURN(SI_SM_CALL_WITH_DELAY);
	}

	if ((bt->state != BT_STATE_IDLE) &&
	    (bt->state <  BT_STATE_PRINTME)) {		/* check timeout */
		bt->timeout -= time;
		if ((bt->timeout < 0) && (bt->state < BT_STATE_RESET1))
			return error_recovery(bt,
					      status,
					      IPMI_TIMEOUT_ERR);
	}

	switch (bt->state) {

	/* Idle state first checks for asynchronous messages from another
	   channel, then does some opportunistic housekeeping. */

	case BT_STATE_IDLE:
		if (status & BT_SMS_ATN) {
			BT_CONTROL(BT_SMS_ATN);	/* clear it */
			return SI_SM_ATTN;
		}

		if (status & BT_H_BUSY)		/* clear a leftover H_BUSY */
			BT_CONTROL(BT_H_BUSY);

		/* Read BT capabilities if it hasn't been done yet */
		if (!bt->BT_CAP_outreqs)
			BT_STATE_CHANGE(BT_STATE_CAPABILITIES_BEGIN,
					SI_SM_CALL_WITHOUT_DELAY);
		bt->timeout = bt->BT_CAP_req2rsp;
		BT_SI_SM_RETURN(SI_SM_IDLE);

	case BT_STATE_XACTION_START:
		if (status & (BT_B_BUSY | BT_H2B_ATN))
			BT_SI_SM_RETURN(SI_SM_CALL_WITH_DELAY);
		if (BT_STATUS & BT_H_BUSY)
			BT_CONTROL(BT_H_BUSY);	/* force clear */
		BT_STATE_CHANGE(BT_STATE_WRITE_BYTES,
				SI_SM_CALL_WITHOUT_DELAY);

	case BT_STATE_WRITE_BYTES:
		if (status & BT_H_BUSY)
			BT_CONTROL(BT_H_BUSY);	/* clear */
		BT_CONTROL(BT_CLR_WR_PTR);
		write_all_bytes(bt);
		BT_CONTROL(BT_H2B_ATN);	/* can clear too fast to catch */
		BT_STATE_CHANGE(BT_STATE_WRITE_CONSUME,
				SI_SM_CALL_WITHOUT_DELAY);

	case BT_STATE_WRITE_CONSUME:
		if (status & (BT_B_BUSY | BT_H2B_ATN))
			BT_SI_SM_RETURN(SI_SM_CALL_WITH_DELAY);
		BT_STATE_CHANGE(BT_STATE_READ_WAIT,
				SI_SM_CALL_WITHOUT_DELAY);

	/* Spinning hard can suppress B2H_ATN and force a timeout */

	case BT_STATE_READ_WAIT:
		if (!(status & BT_B2H_ATN))
			BT_SI_SM_RETURN(SI_SM_CALL_WITH_DELAY);
		BT_CONTROL(BT_H_BUSY);		/* set */

		/* Uncached, ordered writes should just proceeed serially but
		   some BMCs don't clear B2H_ATN with one hit.  Fast-path a
		   workaround without too much penalty to the general case. */

		BT_CONTROL(BT_B2H_ATN);		/* clear it to ACK the BMC */
		BT_STATE_CHANGE(BT_STATE_CLEAR_B2H,
				SI_SM_CALL_WITHOUT_DELAY);

	case BT_STATE_CLEAR_B2H:
		if (status & BT_B2H_ATN) {	/* keep hitting it */
			BT_CONTROL(BT_B2H_ATN);
			BT_SI_SM_RETURN(SI_SM_CALL_WITH_DELAY);
		}
		BT_STATE_CHANGE(BT_STATE_READ_BYTES,
				SI_SM_CALL_WITHOUT_DELAY);

	case BT_STATE_READ_BYTES:
		if (!(status & BT_H_BUSY))	/* check in case of retry */
			BT_CONTROL(BT_H_BUSY);
		BT_CONTROL(BT_CLR_RD_PTR);	/* start of BMC2HOST buffer */
		i = read_all_bytes(bt);		/* true == packet seq match */
		BT_CONTROL(BT_H_BUSY);		/* NOW clear */
		if (!i) 			/* Not my message */
			BT_STATE_CHANGE(BT_STATE_READ_WAIT,
					SI_SM_CALL_WITHOUT_DELAY);
		bt->state = bt->complete;
		return bt->state == BT_STATE_IDLE ?	/* where to next? */
			SI_SM_TRANSACTION_COMPLETE :	/* normal */
			SI_SM_CALL_WITHOUT_DELAY;	/* Startup magic */

	case BT_STATE_LONG_BUSY:	/* For example: after FW update */
		if (!(status & BT_B_BUSY)) {
			reset_flags(bt);	/* next state is now IDLE */
			bt_init_data(bt, bt->io);
		}
		return SI_SM_CALL_WITH_DELAY;	/* No repeat printing */

	case BT_STATE_RESET1:
		reset_flags(bt);
		drain_BMC2HOST(bt);
		BT_STATE_CHANGE(BT_STATE_RESET2,
				SI_SM_CALL_WITH_DELAY);

	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->timeout = BT_RESET_DELAY * 1000000;
		BT_STATE_CHANGE(BT_STATE_RESET3,
				SI_SM_CALL_WITH_DELAY);

	case BT_STATE_RESET3:		/* Hold off everything for a bit */
		if (bt->timeout > 0)
			return SI_SM_CALL_WITH_DELAY;
		drain_BMC2HOST(bt);
		BT_STATE_CHANGE(BT_STATE_RESTART,
				SI_SM_CALL_WITH_DELAY);

	case BT_STATE_RESTART:		/* don't reset retries or seq! */
		bt->read_count = 0;
		bt->nonzero_status = 0;
		bt->timeout = bt->BT_CAP_req2rsp;
		BT_STATE_CHANGE(BT_STATE_XACTION_START,
				SI_SM_CALL_WITH_DELAY);

	/* Get BT Capabilities, using timing of upper level state machine.
	   Set outreqs to prevent infinite loop on timeout. */
	case BT_STATE_CAPABILITIES_BEGIN:
		bt->BT_CAP_outreqs = 1;
		{
			unsigned char GetBT_CAP[] = { 0x18, 0x36 };
			bt->state = BT_STATE_IDLE;
			bt_start_transaction(bt, GetBT_CAP, sizeof(GetBT_CAP));
		}
		bt->complete = BT_STATE_CAPABILITIES_END;
		BT_STATE_CHANGE(BT_STATE_XACTION_START,
				SI_SM_CALL_WITH_DELAY);

	case BT_STATE_CAPABILITIES_END:
		i = bt_get_result(bt, BT_CAP, sizeof(BT_CAP));
		bt_init_data(bt, bt->io);
		if ((i == 8) && !BT_CAP[2]) {
			bt->BT_CAP_outreqs = BT_CAP[3];
			bt->BT_CAP_req2rsp = BT_CAP[6] * 1000000;
			bt->BT_CAP_retries = BT_CAP[7];
		} else
			printk(KERN_WARNING "IPMI BT: using default values\n");
		if (!bt->BT_CAP_outreqs)
			bt->BT_CAP_outreqs = 1;
		printk(KERN_WARNING "IPMI BT: req2rsp=%ld secs retries=%d\n",
			bt->BT_CAP_req2rsp / 1000000L, bt->BT_CAP_retries);
		bt->timeout = bt->BT_CAP_req2rsp;
		return SI_SM_CALL_WITHOUT_DELAY;

	default:	/* should never occur */
		return error_recovery(bt,
				      status,
				      IPMI_ERR_UNSPECIFIED);
	}
	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,
};